REVIEW | doi:10.20944/preprints201912.0149.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: damage detection; machine learning; principal component analysis; composites; micromechanics of damage; continuum damage mechanics
Online: 11 December 2019 (04:50:48 CET)
The loss of integrity and adverse effect on mechanical properties can be concluded as attributing miro/macro-mechanics damage in structures, especially in composite structures. Damage as a progressive degradation of material continuity in engineering predictions for any aspects of initiation and propagation requires to be identified by a trustworthy mechanism to guarantee the safety of structures. Besides the materials design, structural integrity and health are usually prone to be monitored clearly. One of the most powerful methods for the detection of damage is machine learning (ML). This paper presents the state of the art of ML methods and their applications in structural damage and prediction. Popular ML methods are identified and the performance and future trends are discussed.
ARTICLE | doi:10.20944/preprints201905.0151.v1
Subject: Business, Economics And Management, Economics Keywords: climate change; adaptation; loss & damage; damage function; return period; tropical cyclone
Online: 13 May 2019 (10:07:41 CEST)
This paper constructs a model of climate-related damage for small island developing states (SIDS). We focus on the loss of private productive capital stocks through extreme climate events. In contrast to most economic analyses of climate impacts, which assume temperature-dependent damage functions, we draw on the engineering literature to allow for a greater or lesser degree of anticipation of climate change when designing capital stocks and balancing current adaptation expenditure against future loss & damage. We apply the model to tropical storm damage in the small island developing state of Barbados and show how anticipatory behavior changes the damage to infrastructure for the same degree of climate change. Thus, in the model, damage depends on behavior as well as climate variables.
ARTICLE | doi:10.20944/preprints202004.0500.v1
Online: 28 April 2020 (14:24:57 CEST)
A rehabilitation technique for asphalt pavements with geosynthetic is the application of impregnated nonwoven geotextiles between deteriorated and new asphalt overlays. The performance investigation of impregnated geotextiles proves that they are enhancing in mechanical and hydraulic properties. Although, the installation process may cause severe impacts on these materials’ performance. During the installation, the geotextile suffers damage due to the traffic of high load vehicles, as compactors and pavers, and the friction with granular materials found under its layer or poured above it. This paper aims to investigate how the damage caused by granular materials on nonwoven geotextiles impregnated with different asphalt emulsions effect on their strength resistance and permittivity. From two types of nonwoven geotextiles: polypropylene and polyethylene terephthalate, the comparison uses geotextiles in three conditions: not impregnated, impregnated with asphalt emulsion of rapid setting, and impregnated with asphalt emulsion changed by an elastomeric polymer. Part of the samples followed the damage according to ISO 10722 procedure, placed between three different scenarios of granular materials, applying gravel, sand, and clay. After the damage process, the samples were submitted to mechanical and hydraulic properties evaluations.
ARTICLE | doi:10.20944/preprints201811.0191.v1
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: gradual damage behaviour; damage propagation; modal properties; composite rotor; structural dynamic behaviour
Online: 8 November 2018 (08:57:15 CET)
Fibre-reinforced composite structures under complex loads exhibit gradual damage behaviour with a degradation of effective mechanical properties and change of their structural dynamic behaviour. Damage manifests itself as spatial increase of inter-fibre failure and delamination-growth, resulting in local changes of stiffness. These changes affect not only the residual strengths but more importantly the structural dynamic behaviour. In case of composite rotors, this can lead to catastrophic failure if an eigenfrequency coincides with the rotational speed. The description and analysis of the gradual damage behaviour of composite rotors therefore provides the fundamentals for a better understanding of unpredicted structural phenomena. The gradual damage behaviour on the example of composite rotors and the resulting damage-dependent dynamic behaviour is experimentally investigated under propagating damage for combined out-of-plane and in-plane loads. A novel observation is reported, where monotonic increase of damage results in non-monotonic frequency shift of significant amount of eigenfrequencies.
ARTICLE | doi:10.20944/preprints202305.1750.v1
Subject: Chemistry And Materials Science, Ceramics And Composites Keywords: PRAMCs; TiB2 particles; Numerical simulation; Damage factor; Linear damage evolution law; 3D RVE
Online: 25 May 2023 (07:17:02 CEST)
In order to study the effect of TiB2 particles on the mechanical properties of TiB2/6061Al composites, a series of TiB2/6061Al 3D representative volume element (RVE) were established based on SEM photos. This model took into account the ductile damage of the matrix and the traction separation behavior of the interface, and the linear damage evolution law was introduced to characterize the stiffness degradation behavior of the matrix elements. The mixed boundary conditions were used for RVE tensile experiments, and the accuracy of the predicted result was verified by the agreement of the experimental stress-strain curve. Results show that the addition of TiB2 particles can effectively promote the load-bearing capacity of the composite, but elongation is reduced. With the weight fraction of TiB2 increasing from 2.5% to 12.5%, the elastic modulus, yield strength, and tensile strength are increased by 8%, 10.37%, and 11.55% respectively, while the elongation decreased by 10%. The clustering rate of the TiB2 particles is also an important factor affecting the toughness of the composites. With the increase in the clustering rate of TiB2 particles from 20% to 80%, the load-bearing capacity of the composites is not improved, and the elongation of the composites is reduced by 8%. Moreover, the high strain region provides a fast expansion path for crack propagation and the particle spacing is a crucial factor that affects the stress field.
ARTICLE | doi:10.20944/preprints202107.0154.v1
Subject: Engineering, Automotive Engineering Keywords: microcracking; concrete; feature detection; damage detection; structural health monitoring; CNN based damage classification
Online: 6 July 2021 (13:34:21 CEST)
High costs for the repair of concrete structures can be prevented if damage at an early stage of degradation is detected and precautionary maintenance measures are applied. To this end, we use numerical wave propagation simulations to identify simulated damage in concrete using convolutional neural networks (CNN). Damage in concrete subjected to compression is modeled at the mesoscale using the discrete element method. Ultrasonic wave propagation simulation on the damaged concrete specimens are performed using the rotated staggered finite-difference grid method. The simulated ultrasonic signals are used to train a CNN based classifier capable of classifying three different damage stages (microcrack initiation, microcrack growth and microcrack coalescence leading to macrocracks). The performance of the classifier is improved by refining the dataset via an analysis of the averaged envelope of the signal. The classifier using the refined dataset has an overall accuracy of 90%.
ARTICLE | doi:10.20944/preprints202212.0033.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: bedrock; building; damage; earthquake; planning
Online: 2 December 2022 (02:22:20 CET)
Recently on the November 4, 2022 at 03:00 PM, a Mww 5.6 earthquake struck Cianjur district of West Java province, Indonesia. To our best knowledge, an earthquake will cause a massive damage to the manmade infrastructure and this responsible for a massive casualty. A building damage is affected by various determinant factors. One of important factors is the geological bedrock variations. Here this research aiming to elaborate the associations of geological bedrocks in Cianjur district with residential building damages caused by recent earthquakes. The results confirm that majority of building damages account for 54.67% of the total building was associated with quaternary volcanic bedrocks. The second massive building damages were observed for Andesitic Dacitic volcanic rocks accounted for 32.07%. To conclude, elaborations of geological bedrock-building damage will contribute to the better planning in the future that can reduce the damages in the urban settings.
ARTICLE | doi:10.20944/preprints202103.0278.v1
Online: 10 March 2021 (13:01:45 CET)
Samarinda City is one of the most attractive cities in Borneo Island (Indonesia) and also as a capital city of EastBorneo Province. The expansion of urban areas becomes essential due to rapid population and housing demand. Base on the statistical report, the annual population growth rate is 0.018% from the year 2016-2017 with a total population of 843446 inhabitants. Many natural disasters occur in some areas in this city, especially flooding. This natural disaster occurs almost every year, many people suffered and forced to evacuate. In 2018 there is 3 flood event with 28311 people was suffered and evacuated, and 5170 houses were flooded . During the flood event, it was very possible to gain damages to their property and make traffic stuck. One common way to reducing the damages is using Early Warning Systems (EWS). Early warning is a major element for disaster risk reduction, including damages. To prevent and mitigate the impact of a disaster, many countries had taken action to build various methods of a public warning system. An effective early warning system focused on people-centered and comprises the following element, such as risk knowledge, technical monitoring and service, communication and dissemination of warnings, and community response capability . Related to the existing condition which Samarinda is a Muslim-dominated city and obviously has a lot of a number of mosques. This is a good potency to develop an early warning system because every mosque has a loudspeaker for echoing Adzan (Muslim prayer-calling). With this existing condition, the loudspeaker can be utilized as a flood outdoor-voice warning announcer. The aim of this study is to briefly introduce the strategy of dissemination early warning by utilizing mosques. The hope of early warning dissemination is giving enough time to the people to evacuate their property to reduce damages and possibly to giving information to avoiding traffic stuck (in a certain location)due to flooding. The results of this study can be used as input for decision-makers to develop effective flood management strategies and policies, especially in the case of an early warning system where not well-developed in Samarinda.
ARTICLE | doi:10.20944/preprints202311.0157.v2
Subject: Social Sciences, Urban Studies And Planning Keywords: historic sites; spatial damage degree; K-means clustering; K nearest neighbor classification; Damage factors
Online: 3 November 2023 (04:04:34 CET)
Historic sites are important components of every city's cultural history because they preserve rich historical knowledge and distinctive values passed down from previous generations to the present. Due to the progress of urbanization and modernization, many historic sites face pressure from damage and transformation. In this paper, a method for assessing cultural heritage damage was developed to measure the extent of spatial damage in historic sites. Using sample data obtained in Xiyang, Qixian, and Xiaoyi, all historic cities in Shanxi Province, Mainland China, and combined weights were estimated using the Delphi technique and the CRITIC weight method. Following this, the Spatial Damage Degree Model (SDDM) based on K-means cluster analysis and K-nearest neighbor (KNN) classification was developed. The findings show that the model efficiently solves the problem of assessing spatial damage levels in historic sites. Through multiple linear regression analysis, it was shown that the damage to historic sites was predominantly caused by three factors: natural erosion, construction damage, and planning and policy. SDDM was used to calculate the spatial damage levels of historic sites, allowing conservators to fully comprehend the features and concerns related to historic sites. As a result, more scientific and rational preservation approaches may be developed, improving the efficiency of historic site restoration and conservation and encouraging the sustainable development of urban and rural heritage.
ARTICLE | doi:10.20944/preprints202310.2053.v1
Subject: Chemistry And Materials Science, Electronic, Optical And Magnetic Materials Keywords: µLED; GaN; KOH treatment; sidewall damage
Online: 31 October 2023 (09:54:40 CET)
InGaN-based red micro light-emitting diodes (µLEDs) of different sizes prepared in this work. The red GaN epilayers were grown on a 4-inch sapphire substrate through metal organic chemical vapor deposition (MOCVD). Etching, sidewall treatment, and p- and n- contact deposition was involved in the fabrication process. Initially, the etching process would cause undesirable damages to the GaN sidewalls, which leads to an increase in leakage current. Hence, we employed KOH wet treatment to rectify the defects on the sidewalls and conducted a comparative and systematic analysis on electrical as well as optical properties. We observed that the µLEDs with a size of 5µm exhibited substantial leakage current, which was effectively mitigated by the application of KOH wet treatment. In terms of optical performance, the arrays with KOH demonstrated improved Light Output Power (LOP). Additionally, while photoelectric performance exhibited a decline with increasing current density, the devices treated with KOH consistently outperformed their counterparts in terms of optoelectronic efficiency. It is noteworthy that the optimized devices displayed enhanced photoelectric characteristics without significantly altering their original peak wavelength and FWHM. Our findings point to the elimination of surface non-radiative recombination by KOH wet treatment, thereby enhancing the performance of small-sized red µLEDs which has significant potential in realizing full-color micro-displays in near-eye projection applications.
ARTICLE | doi:10.20944/preprints202305.1860.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: : Cisplatin; cilostazol; tadalafil; pentoxifylline; testicular damage
Online: 26 May 2023 (05:22:12 CEST)
Despite being extremely potent against malignancies, cisplatin (CIS) has limited practical applicability due to its adverse effects such as testicular damage. Consequently, it becomes necessary to reduce its toxicity. In this study, cilostazol, a selective phosphodiesterase-3 inhibitor that is frequently used in the treatment of intermittent claudication, was examined for its ability to abrogate CIS-induces testicular toxicity and its ameliorative effect was compared with two phosphodiesterase inhibitors, tadalafil and pentoxifylline. The study also focused on the possible mechanisms involved in the proposed protective effect. Ten groups of rats were included; Group (1): control, Groups (2-4): 5 mg/kg tadalafil or 75 mg/kg pentoxifylline or 20 mg/kg cilostazol respectively), Group (5):7 mg/kg CIS, Group (6&7): CIS + 5 mg/kg tadalafil or 75 mg/kg pentoxifylline, Group (8-10) CIS+ 5, 10 or 20 mg/kg cilostazol respectively. CIS treated rats showed a significant decrease in testicular function, serum testosterone and reduced glutathione levels, and significant elevation in malondialdehyde, total nitrite levels, tumor necrosis factor-alpha and nuclear factor-kappa β alongside caspase-3. These outcomes were confirmed by marked testicular architecture deterioration. Contrary, Cilostazol in a dose-dependent manner showed potential protection against testicular toxicity, reversion of the disrupted testicular function and improvement of the histological alterations through rebalancing of oxidative stress, inflammatory and apoptotic biomarkers. In addition, cilostazol exerted more pronounced protective effect in comparison to tadalafil and pentoxifylline. In conclusion, administrations of cilostazol might ameliorate cisplatin-induced testicular impairment through alteration of oxidative stress, inflammation, and apoptotic pathway, offering a promising treatment for cisplatin -intoxication in the testes.
ARTICLE | doi:10.20944/preprints202305.0370.v1
Online: 5 May 2023 (14:09:00 CEST)
Free-edge effect is one of the factors affecting the mechanical properties of three-dimensional woven composites under tensile load. However, current research is relatively poorly understood regarding the effect of free-edge on the stiffness and strength of the material. This paper aims at examining the influence of free-edge effect on the mechanical properties of 3D woven composites under tension through experimental and simulation mathods. The three-dimensional DIC technique is used to collect the full-field strains on the specimen surface during the test, and the stress-strain differences in different regions in the width direction are analyzed, and the overlap of the curves in each region is found to be high. Experimental studies are conducted on specimens of different widths (within the range of 15-20 mm), and the results indicate that the differences in mechanical properties of 3D woven composites under tension loading in this width range are not significant. A progressive damage finite element model is developed for calculation and compared with experimental results.
ARTICLE | doi:10.20944/preprints202012.0083.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: genitalia; damage; instar; insect pest; dimorphism
Online: 3 December 2020 (11:31:35 CET)
The coffee leaf miner Leucoptera coffeella (Guérin-Mèneville & Perrottet), is a key pest in coffee producing countries. During their development, the larvae feed on the palisade parenchyma of the leaves forming mines. As a result, the photosynthetic area of the plant decreases, affecting coffee production. Despite the severity of the damage caused by coffee leaf miner (CLM), morphological aspects of the larval development and the adult genitalia remain unknown. It is important to identify more susceptible targets to an efficient and narrow control by natural or synthetic approaches, relies on determining the larval instars. Equally important is the sexing of the adult, in experiments aiming efficient ways to control CLM, as the study of pheromone-based control methods. This work presents the first morphological description of the four larval instars and the adult genitalia of L. coffeella. In each larval instar, we measured the Mean ± SD (mm) of the cephalic capsules (1st 0,14±0,03; 2nd 0,25±0,04; 3rd 0,32±0,03; 4th 0,42±0,03) and observed the following morphological details: primary setae, prolegs, crochets and ecdysial line of the cephalic capsule. In the adults, we observed the sexual structures present in both genitalia: male - bulbus ejaculatorius, valva, anellus, gnathos and aedeagus and female - ovipositor, sclerite and corpus bursae. The dissection of the adult specimens confirmed that the external morphology corresponds to the correct sex attribution in CLM adults. These results may support innovative and improved control strategies for CLM Integrated Pest Management (IPM).
ARTICLE | doi:10.20944/preprints201704.0118.v2
Subject: Engineering, Civil Engineering Keywords: bond; concrete; reinforcement; damage-plasticity; failure
Online: 25 August 2017 (08:01:21 CEST)
The structural performance of reinforced concrete relies heavily on the bond between reinforcement and concrete. In nonlinear finite element analyses, bond is either modelled by merged, also called perfect bond, or coincident with slip, also called bond-slip, approaches. Here, the performance of these two approaches for the modelling of failure of reinforced concrete was investigated using a damage-plasticity constitutive model in LS-DYNA. Firstly, the influence of element size on the response of tension-stiffening analyses with the two modelling approaches was investigated. Then, the results of the two approaches were compared for plain and fibre reinforced tension stiffening and a drop weight impact test. It was shown that only the coincident with slip approach provided mesh insensitive results. However, both approaches were capable of reproducing the overall response of the experiments in the form of load and displacements satisfactorily for the meshes used.
ARTICLE | doi:10.20944/preprints202310.1373.v1
Subject: Engineering, Aerospace Engineering Keywords: Fatigue; Residual strength; Stress ratio; Damage rule
Online: 20 October 2023 (16:22:09 CEST)
This paper discusses the theoretical and experimental correlations between fatigue and static strength statistical distributions. We use a two-parameter residual strength model that obeys the qualitative Strenght-Life Equal-Rank (SLERA) assumption for guidance. The modeling approach consists of recovering the model's parameters by best fitting the constant amplitude (CA) fatigue data at a given stress ratio, R, and the experimental Weibull parameters of the static strength distribution function. Once the model's parameters are fixed, its capabilities, potential, and limits are discussed by comparing its predictions with residual strength and fatigue data obtained at different stress ratios, R. Moreover, from a preliminary analysis, the theoretical extension of the model's capabilities to variable amplitude loadings is conceptualized. The application of Miner's rule is also discussed and compared with a new damage rule to analyze the fatigue responses under variable amplitude loadings.
ARTICLE | doi:10.20944/preprints202310.0578.v1
Subject: Engineering, Safety, Risk, Reliability And Quality Keywords: infrastructure damage; transportation vulnerability; roadway; risk; hazard
Online: 10 October 2023 (12:21:08 CEST)
Wildfires can be destructive to highway infrastructure. Despite the substantial number of wildfires experienced every year, research on the physical impacts of wildfire on highways has been understudied. This research examines historical and potential future highway physical damage from wildfires. To accomplish our research objectives, we examined three major areas related to physical harm to highways and the consequences of that damage – physical characteristics, roadway impacts, and traffic impacts. These categories were subsequently broken into additional metrics, the first being physical characteristics, which includes length of highway affected and reduced average daily traffic (RADT) impacts during the event. Roadway impacts were broken into the number of trees requiring removal (those that present a danger either standing or fallen), pavement damage (burning asphalt concrete), slope/rock scaling (loose hazard rocks/vegetation), and structural damage (guardrail, signs, and delineators). Traffic impacts included the need for traffic control, road closures required, and reduced annual average daily traffic (RAADT) impacts for the year. The physical characteristics on the three highways researched during the 2020 Oregon Labor Day wildfires (Beachie Creek, Archie Creek, and Holiday Farm) indicated less than 61% of the highways were affected. The highway impacts, which included damage from hazard trees, damage to various structures – guardrail, signs, and delineators as well as bridges, slope/rock scaling damage and pavement destruction – averaged 34% for the three highways, while the three of eight arterial highway routes studied in the Oregon Cascades saw a 21% reduction in AADT. Results from this study can be used not only to assess physical damage to highways from wildfires, but as a baseline for measuring and assessing potential future wildfire highway impacts.
ARTICLE | doi:10.20944/preprints202308.2197.v1
Subject: Engineering, Civil Engineering Keywords: damage identification; modal curvature; beamforming algorithms; MVDR
Online: 1 September 2023 (03:34:57 CEST)
This paper presents an approach to damage identification in beams by modal curvatures based on the use of beamforming algorithms. These processors have been successfully used in acoustics for the last thirty years to solve the inverse problems encountered in source recognition and image reconstruction, based on ultrasonic waves. In addition, beamformers apply to a broader range of problems in which the forward solutions are computable and measurable, especially regarding the field of structural vibrations, where the use of such estimators has not received attention to date. In this paper, modal curvatures will play the role of the replica vectors of the imaging field. By means of numerical studies and experimental tests on a steel beam, we motivate the choice of modal curvatures as observed quantities. Furthermore, we compare the performance of the Bartlett and minimum variance distortionless beamformers (MVDR) with an estimator based on the simple minimization of the difference between model and measured data. The results suggest that the application of the MVDR beamformer is highly effective, especially in cases of slight damage between two sensors. MVDR enabled both damage localization, and quantification.
ARTICLE | doi:10.20944/preprints202305.0630.v1
Online: 9 May 2023 (09:52:46 CEST)
The paper explores the potential of a low-cost advanced video-based technique for the assessment of structural damage induced to buildings by seismic loading. A low-cost high-speed video camera was utilized for motion magnification (MM) processing of footages of a two-story reinforced concrete frame building subjected to shaking table tests. The damage after seismic loading was estimated by analyzing the dynamic behavior (i.e. in terms of modal parameters) and the structural deformations of the building in the MM videos. The results by MM were compared for method validation to damage assessment obtained by the analyses of conventional accelerometers and high-precision optical markers tracked by a passive 3D motion capture system. Also, 3D laser scanning to obtain an accurate survey of the building geometry before and after the seismic tests was carried out. In particular, accelerometers were also processed and analyzed by using several stationary and non-stationary techniques with the aim to analyze the linear behavior of the undamaged structure and the nonlinear structural behavior during damaging shaking table tests. The proposed MM-based procedure provided accurate estimate of the main modal frequency and the damage location through the analysis of modal shapes, which were confirmed by advanced analyses of accelerometric data.
ARTICLE | doi:10.20944/preprints202305.0605.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: acute fluorosis; tetramethylpyrazine; liver; oxidative damage; Nrf2
Online: 9 May 2023 (08:34:59 CEST)
Excessive intake of fluoride, one of the trace elements to maintain health, leads to liver injury. Tetramethylpyrazine (TMP) is a kind of traditional Chinese medicine monomer with good antioxidant and hepatoprotective function. The aim of this study was to investigate the effect of TMP on liver injury induced by acute fluorosis. A total of 60 1-month-old male Institute of Cancer Research mice without carriage of pathogenic bacteria were selected. All mice were fed adaptively for one week, and then randomly divided into 5 groups: control (K) group, model (F) group, low-dose (LT) group, medium-dose (MT) group and high-dose (HT) group. The control and model group were given distilled water, while 40 mg/kg (LT), 80 mg/kg (MT) and 160 mg/kg (HT) TMP were fed by gavage for two weeks with the maximum gavage volume of mice is 0.2ml/10g/d. Except for the control group, all groups were given fluoride (35 mg/kg) by intraperitoneal injection on the last day of the experiment. The results of this study showed that compared with the model group, TMP alleviated the pathological changes of liver induced by fluoride and improved the ultrastructure of liver cells; TMP significantly decreased the levels of ALT, AST and MDA (P <0.05), and increased the levels of T-AOC, T-SOD and GSH (P <0.05). The results of mRNA detection showed that TMP significantly increased the mRNA expression levels of Nrf2, HO-1, CAT, GSH-Px and SOD in liver compared with model group (P <0.05). In conclusion, TMP can inhibit oxidative stress by activating Nrf2 pathway and alleviate liver injury induced by fluoride.
ARTICLE | doi:10.20944/preprints202201.0376.v1
Subject: Computer Science And Mathematics, Applied Mathematics Keywords: flood damage methodology; hydraulic infrastructure; resilience; indicators
Online: 25 January 2022 (10:27:21 CET)
Critical infrastructures are those that are essential. For this type of infrastructure, it is necessary to implement analytical methodologies that will allow us to quickly obtain the susceptibility or resilience and possible damage generated in extreme precipitation episodes, through a holistic perspective in which the factors linked to hydrological risk intervene. In particular, urban hydraulic infrastructures are analyzed considering the degree of criticality, defined as the number of interactions on the different activities of the population. For this purpose, a hydrological risk analysis methodology is required. This methodology is focused on an integral approach of the system indicators to be analyzed and linked to the hydrological threat. This work proposes to delimit and analyze those factors that involve risk using an analytical expression. This model will estimate the damage to these infrastructures breaking down the factors involved in the risk equation and analyzing their variability according to the intrinsic characteristics linked to them as well as the interaction with external factors.
ARTICLE | doi:10.20944/preprints202111.0563.v1
Subject: Physical Sciences, Optics And Photonics Keywords: Laser induces damage threshold; ZnGeP2; Magnetorheological polish
Online: 30 November 2021 (11:50:44 CET)
Magnetorheological processing was applied to polish the working surfaces of the ZnGeP2 single crystal, in which a non-aqueous liquid with magnetic particles of carbonyl iron with the addition of nanodiamonds was used. Samples of a single crystal ZnGeP2 with an angstrom level of surface roughness were received. the use of MRP has allowed more accurately characterizing possible structural defects that have emerged on the surface of a single crystal and have a size of ~ 0.5-1.5 μm. the LIDT value at the indicated or-ders of magnitude of the surface roughness parameters is determined not by the quality of polishing, but by the number of point depressions caused by physical limitations of the structural configuration of the crystal volume. These results are in good agreement with the assumption made about a significant effect of the concentration of dislocations in a ZnGeP2 crystal on LIDT.
ARTICLE | doi:10.20944/preprints202103.0411.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: HDV; mouse model; AAV; HDAg; Liver damage
Online: 16 March 2021 (10:14:06 CET)
Hepatitis delta virus (HDV) infection causes the most severe form of viral hepatitis but little is known about the molecular mechanisms involved. The recently developed HDV mouse model based on the delivery of HDV replication-competent genomes using adeno-associated vectors (AAV) develop a liver pathology very similar to the human disease, and allowed us to perform mechanistic studies. We have generated different AAV-HDV mutants to eliminate the expression HDV antigens (HDAgs), characterized them both in vitro and in vivo. We confirmed that S-HDAg is essential for HDV replication and cannot be replaced by L-HDAg or host cellular proteins, and the L-HDAg is essential for HDV infectious particle production. We have also found that the lack of L-HDAg resulted in the increase of of S-HDAg expression levels and the exacerbation of liver damage which is T cell independent but is associated with an increment in liver inflammation. Interestingly, early expression of L-HDAg significantly ameliorated the liver damage induced by the mutant expressing only the S-HDAg. In summary, the use of AAV-HDV represents a very attractive platform to interrogate in vivo the role of viral components in the HDV life cycle and to better understand the mechanism of HDV-induced liver pathology.
ARTICLE | doi:10.20944/preprints202006.0201.v1
Subject: Engineering, Civil Engineering Keywords: piezoceramic sensor; reinforced concrete; force; earthquake; damage.
Online: 16 June 2020 (08:34:24 CEST)
To quantify damage to reinforced concrete (RC) column members after an earthquake, an engineer needs to know the maximum applied force that was generated by the earthquake. Therefore, in this work, piezoceramic transducers are used to detect the applied force on an RC column member under dynamic loading. To investigate the use of post-embedded piezoceramic sensors in detecting the force that is applied to RC columns, eight full-size RC column specimens with various failure modes are tested under specific earthquake loadings. Post-embedded piezoceramic sensors are installed at a range of depths (70-80 mm) beneath the surface of a column specimen to examine the relationship between the signals that are obtained from them and the force applied by the dynamic actuator. The signals that are generated by the post-embedded piezoceramic sensors, which correlate with the applied force, are presented. These results indicate that the post-embedded piezoceramic sensors have great potential as tools for measuring the maximum applied force on an RC column in an earthquake. Restated, signals that are obtained from post-embedded piezoceramic sensors on an RC column in an earthquake can be used to determine the applied force and corresponding damage or residual seismic capacity.
ARTICLE | doi:10.20944/preprints201812.0117.v1
Subject: Biology And Life Sciences, Toxicology Keywords: radioresistance; DNA-damage recognition; CRISPRa; multiplex overexpression
Online: 11 December 2018 (09:27:42 CET)
Current understanding of mechanisms of cellular resistance to genotoxic stress is incomplete but is critical for a variety of medical applications. Recent developments in the CRISPR/Cas technologies open new opportunities for targeted interrogation of resistance genes and pathways. In the present work, we used nuclease dead Cas9 constructs to achieve targeted overexpression of endogenous genes encoding two essential subunits of DNA damage sensor complex, XPC and HR23B, in HEK293T cells. Both individual and simultaneous overexpression of the two genes was achieved and the effects on cellular resistance to ionizing radiation and paraquat was examined. Using the fluorometric microculture cytotoxicity assay, we showed that simultaneous, but not separate overexpression of the two genes lead to a 30% increase in survivability. Irradiated cells that overexpressed both XPC and HR23B genes showed higher clonogenic capacity and proliferation rate compared to the irradiated transfection control as revealed by the clonogenic survival assay. Modulation of the gene expression did not affect cell resistance to paraquat. In summary, our results demonstrate a high potential of CRISPR/dCas9-enabled multiplex overexpression of stress-response genes in functionally justified combinations, exemplified here by the XPC-HR23B complex, for achieving an enhanced cellular radioresistance.
REVIEW | doi:10.20944/preprints201810.0481.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: fluoride; fluorosis; fluoride systemic damage; human health
Online: 22 October 2018 (08:25:40 CEST)
The use of fluoride (F-) for decreasing the prevalence and incidence of tooth decay was the greatest worldwide preventive public health measure of the 20th century. There have been controversial reports about the benefits of the use of F-, because in small amounts it helps prevent dental caries, but in high concentrations it can be potentially toxic and harmful to dental and systemic health. Since the mid-20th century, F- has been studied by toxicologists, looking at its deleterious effects in human populations. During the last decade, the interest on the undesirable effects has resurfaced because of the knowledge that it interacts with the cellular system, even in low doses, with a very small safety margin. Acute ingestion of toxic amounts of fluoride can cause corrosive gastric mucosa injury. Also respiratory effects such as bleeding, pulmonary edema, tracheostomy and shortness of breath, have been observed in individuals who inhale hydrogen fluoride. Some researchers had shown that F- is an oxidizing agent and a well-known reversible enzymatic inhibitor that interferes with the enzyme activity of at least 80 proteins, can altered the intracellular redox equilibrium, lipid peroxidation, as well as, alteration in the gene expression and apoptosis induction. The primary purpose of this review is to examine findings of the action of inorganic F-, and an overview of hard and soft tissue disturbances, known as fluorosis. The goal of this review is to enhance understanding of the mechanisms by which F- affects cells with an emphasis on human tissue-specific events.
ARTICLE | doi:10.20944/preprints201808.0303.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: pine bark extract; oxidative stress; muscle damage
Online: 17 August 2018 (12:07:49 CEST)
The purpose of the present study was to examine if 14 days of supplementation with a pine bark extract leading up to and following an exercise test would increase performance and reduce biomarkers associated with muscle damage, inflammation and oxidative stress. The study used a double-blind, placebo controlled, cross-over design. Participants ingested either 800mg pine bark extract or placebo for 14 days prior to the first exercise trial and for 2 days post-exercise. On the exercise day, participants submitted a pre-exercise blood sample, then completed a VO2 peak test until volitional failure. A post-blood sample was collected 1 hour after completion of exercise. Participants returned at 24 & 48 hours after the exercise testing for measures of muscle pain in the lower body using an algometer. Participants then had a 7-day washout period before beginning to crossing over to the alternate treatment. Analysis via ordinal regression demonstrated a significant difference in oxidative stress in the pine bark extract group compared to placebo (ChiSq = 2.63; p = 0.05). The pine bark extract was effective at affording protection from oxidative stress post exercise. Further work should be undertaken to evaluate the findings with other exercise modes or in participants with known metabolic syndrome.
ARTICLE | doi:10.20944/preprints201702.0094.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: laser wavelength; polysilicon; laser damage; thermal shock
Online: 27 February 2017 (06:56:01 CET)
Based on PVDF (piezoelectric sensing techniques), this paper attempts to study the propagation law of shock waves in brittle materials during the process of three-wavelength laser irradiation of polysilicon, and discusses the formation mechanism of thermal shock failure. The experimental results show that the vapor pressure effect and the plasma pressure effect in the process of pulsed laser irradiation lead to the splashing of high temperature and high density melt. With the decrease of the laser wavelength, the laser breakdown threshold decreases and the shock wave is weakened. Because of pressure effect of the laser shock, the brittle fracture zone is at the edge of the irradiated area. The surface tension gradient and surface shear wave caused by the surface wave are the result of coherent coupling between optical and thermodynamics. The average propagation velocity of laser shock wave in polysilicon is 8.47×103m/s, and the experiment has reached the conclusion that the laser shock wave pressure peak exponentially distributes attenuation in the polysilicon.
ARTICLE | doi:10.20944/preprints202203.0188.v1
Subject: Engineering, Civil Engineering Keywords: Seismic Sequence; Machine Learning Algorithms; Repeated Earthquakes; Structural Damage Prediction; Intensity Measures; Damage Accumulation; Machine Learning; Artificial Neural Network
Online: 14 March 2022 (11:57:51 CET)
Advanced machine learning algorithms, have the potential to be successfully applied to many areas of system modelling. In the present study the capability of ten machine learning algorithms in predicting the structural damage of an 8-storey reinforced concrete frame building subjected to single and successive ground motions is examined. From this point of view, the initial damage state of the structural system, as well as 16 well known ground motion intensity measures are adopted as the features of the machine-learning algorithms that aim to predict the structural damage after each seismic event. The structural analyses are performed considering both real and artificial mainshock–aftershock sequences, while the structural damage is expressed in terms of two overall damage indices. The comparative study results in the most efficient damage index, as well as the most promising machine learning algorithm in predicting the structural response of a reinforced concrete building under single or multiple seismic events. Finally, the configured methodology deployed in a user-friendly web-application.
ARTICLE | doi:10.20944/preprints202308.2187.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Krüppel-like factors; myocardial damage; cardiovascular diseases; hypertrophy.
Online: 13 November 2023 (10:02:18 CET)
Cardiac hypertrophy typically follows myocardial damage, a process known to involve members of the Krüppel-Like Factors (KLFs) which have pro-hypertrophic and anti-hypertrophic roles. Our study delved into the molecular mechanisms underlying KLFs-cardiac hypertrophy interplay post myocardial infraction. We induced myocardial dam-age in rats using isoproterenol. Total RNA was extracted from the left ventricle and Quantitative Real Time RT-PCR was conducted to assess the expression of KLFs, cardiac commitment genes, inflammatory markers, and certain conduction-related genes. We devel-oped a computational approach to construct a proteomic network centered on KLFs. Initial results revealed early expression (2-3 days post-induction) of KLF3, KLF4 and KLF6, followed by the subsequent expression of KLF11 and KLF15 (5-8 days after induction). In the maturation stage, KLF12 and KLF13 regulators were found upregulated. IL-6 was gradually found to be upregulated through. Interaction analysis revealed KLF3, KLF8 and KLF12 interacted with cardiac electrical functions. RT-PCR confirmed up-regulation in cardiac genes linked to electrical function and scar maturation. Our findings underscore the central role of KLFs during the modulation of the cardiac hypertrophic response. Dysregulation of KLF expression resulted in damaged myocardium, participating in the progression of abnormal hypertrophy, highlighting their potential as therapeutic targets for heart diseases.
ARTICLE | doi:10.20944/preprints202310.1421.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: potato; cultivars; weeding control methods; herbicides; phytotoxic damage
Online: 23 October 2023 (12:36:46 CEST)
(Background) Phytotoxicity refers to the capacity of chemical substances or environmental factors to have a negative impact on plants. This is a crucial issue in both the context of crop cultivation and environmental protection. (Material and Methods) The research results were based on a 3-year field experiment conducted at the experimental station in Jadwisin (52°28′ N, 21°02′ E) on loamy soil. The experiment was set up using a randomized sub-block design in a split-split-plot arrangement, with three replications. The first-order factor consisted of potato cultivars, while the second-order factors were weed control methods: 1) Control – without protection; 2) mechanical weed control, extensive mechanical treatments to close rows; 3) Sencor 70 WG – pre-emergence (PRE) of potatoes; 4) Sencor 70 WG + Titus 25 WG + Trend 90 EC – PRE of potatoes; 5) Sencor 70 WG – post-emergence (POST) of potatoes; 6) Sencor 70 WG + Titus 25 WG + Trend 90 EC – POST of potatoes; 7) Sencor 70 WG + Fusilade Forte 150 EC – POST of potatoes; 8) Sencor 70 WG + Apyros 75 WG + Atpolan 80 SC – POST of potatoes. The phytotoxic effects of herbicides on potato plants and weeds were assessed every 7 days, starting from the date when the first signs of damage appeared, until they stabilized or disappeared. (Results:) Phytotoxic damage to potato and weed plants were caused by the chemical weed control methods used. The response of potato plants to herbicides was significantly related to the genetic traits of the cultivars and meteorological conditions in the years of research. (Conclusion:) Phytotoxicity is an important aspect in both agriculture and environmental protection. Research on its mechanisms and impact will enable the development of effective plant protection strategies and the preservation of ecosystem balance.
ARTICLE | doi:10.20944/preprints202307.1876.v1
Subject: Biology And Life Sciences, Toxicology Keywords: keto-enol insecticides; DNA damage response; Drosophila germarium.
Online: 27 July 2023 (08:58:21 CEST)
DNA damage response (DDR) pathways in keto-enol genotoxicity have not been characterized, and few studies have reported genotoxic effects in non-target organisms. The present study shows that concentrations of 11.2, 22.4, 37.3 mg/L of Movento® 240SC and 12.3, 24.6, 41.1 mg/L of Envidor® 240SC for 72 h oral exposure induced DSBs by significantly increasing the percentage of γH2AV expression in regions 2b and 3 from the germarium of wildtype females of Drosophila melanogaster Oregon R, compared to the control group (0.0 mg/L of insecticides), by confocal immunofluorescence microscopy. The comparison between both insecticides’ revels that only the Envidor® 240SC induces concentration-dependent DNA damage, as well as structural changes in the germarium. We determined that the DDR induced by Movento® 240SC depends on the activation of the ATMtefu, Chk1grp and Chk2lok kinases by significantly increasing the percentage of expression of γH2AX in regions 2b and 3 of the germarium, and that ATRmei-29D and p53dp53 kinases only respond at the highest concentration of 37.3 mg/L of Movento® 240SC. With the Envidor® 240SC insecticide, we determined that the DDR depends on the activation of the ATRmei-29D/Chk1grp and ATMtefu/Chk2lok kinases, and p53dp53 by significantly increasing the percentage of expression of γH2AX in the germarium.
ARTICLE | doi:10.20944/preprints202307.0124.v1
Subject: Engineering, Mechanical Engineering Keywords: damage detection; sparsity-based approach; finite element; FISTA
Online: 4 July 2023 (03:31:02 CEST)
Model-based approaches form the basis of the majority of damage detection and localization studies; however, built-in online detection technique can offer an alternative for future structural health monitoring technologies. Thus, in this paper, we present a dynamic localization algorithm for damage localization in functionally graded plates. The method depends on the creation of a grid matrix that contains the dynamic response of the structure over time. Subsequently, an optimization process is carried out via a linear equation representing the information contained within the grid to achieve accurate localization of damage. Due to the inherent sparsity of the localization nature, the FISTA algorithm has been employed as a problem solver. The approach is tested in the case of the functionally graded plate under clamped free boundary conditions. Several, damage scenarios were investigated for the case of damage signals on and off the grid. The results show that the proposed approach is capable of accurately predicting damage position and can be suitable for use in low size data systems.
ARTICLE | doi:10.20944/preprints202304.0006.v1
Subject: Biology And Life Sciences, Virology Keywords: Parvoviruses; DNA damage response; Minute Virus of Mice
Online: 3 April 2023 (04:21:03 CEST)
Minute Virus of Mice (MVM) is an autonomous parvovirus of the Parvovirus family that replicates in mouse cells and transformed human cells. MVM genomes localize to cellular sites of DNA damage with the help of their essential non-structural phosphoprotein NS1 to establish viral replication centers. MVM replication induces a cellular DNA damage response that is mediated by signaling through the ATM kinase pathway, while inhibiting induction of the ATR kinase signaling pathway. However, the cellular signals regulating virus localization to cellular DNA damage response sites has remained unknown. Using chemical inhibitors to DNA damage response proteins, we have discovered that NS1 locallization to cellular DDR sites is independent of ATM or DNA-PK signaling, but is dependent on ATR signaling. Pulsing cells with an ATR inhibitor after S-phase entry leads to attenuated MVM replication. These observations suggest that the initial localization of MVM to cellular DDR sites depends on ATR signaling before it is inactivated by vigorous virus replication.
ARTICLE | doi:10.20944/preprints202107.0240.v1
Subject: Engineering, Automotive Engineering Keywords: damage detection; multi-cracked beam; eigenfrequency; deflection; superposition
Online: 12 July 2021 (11:13:05 CEST)
Identifying cracks in the incipient state is essential to prevent the failure of engineering structures. Detection methods relying on the analysis of the changes in modal parameters are widely used because of the advantages they present. In our previous research, we have found that eigenfrequencies were capable of indicating the position and depth of damage when sufficient vibration modes were considered. The damage indicator we developed was based on the relative frequency shifts (RFS). To calculate the RFSs for various positions and depths of a crack, we established a mathematical relation that involved the squared modal curvatures in the healthy state and the deflection of the healthy and damaged beam under dead mass, respectively. In this study, we propose to calculate the RFS for beams with several cracks by applying the superposition principle. We demonstrate that this is possible if the cracks are far enough from each other. In fact, if the cracks are close to each other, the superposition method does not work and we distinguish two cases: (i) when the cracks affect the same beam face, the frequency drop is less than the sum of the individual frequency drops, and (ii) on the contrary, cracks on opposite sides cause a decrease in frequency, which is greater than the sum of the frequency drop due to individual damage. When the RFS curves are known, crack assessment becomes an optimization problem, the cost function being the distance between the measured RFSs and all possible RFSs for several vibration modes. Thus, the RFS constitutes a benchmark that characterizes damage using only the eigenfrequencies. We can accurately locate multiple cracks and estimate their severity trough experiments and thus prove the reliability of the proposed method.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: chronic intermittent hypoxia; autophagy; apoptosis; cardiomyocyte damage; calcineurin
Online: 24 June 2021 (14:58:22 CEST)
Calcineurin plays a key role in cardiovascular pathogenesis by exerting pro-apoptotic effects in cardiomyocytes; however, its involvement in the regulation of cardiomyocyte autophagy under chronic intermittent hypoxia (CIH) remains largely unknown. Here we showed that CIH induced calcineurin activity in H9C2 cells, resulting in the attenuation of adenosine monophos-phate-activated protein kinase (AMPK) signaling and inhibition of H9C2 cell autophagy. Au-tophagy, LC3-II levels, and AMPK phosphorylation were significantly elevated in response to CIH in H9C2 cells by day 3; however, these effects were reversed, and calcineurin activity and apoptosis were significantly increased by day 5. The calcineurin inhibitor, FK506, restored AMPK activation and LC3 protein levels, and reduced CIH-induced H9C2 cell apoptosis, while calcineurin overexpression significantly attenuated the increase in LC3 levels and enhanced H9C2 cell apop-tosis. Calcineurin inhibition failed to induce autophagy or alleviate apoptosis in H9C2 cells ex-pressing a dominant negative K45R AMPK mutant. Autophagy downregulation abrogated the protective effects of FK506-mediated calcineurin inhibition. These results indicated that calcineurin suppressed adaptive autophagy during CIH by downregulating AMPK activation. Our findings showed the underlying mechanisms of calcineurin and autophagy regulation during H9C2 cell survival in response to CIH, and suggested a new strategy for preventing CIH-induced cardiomyocyte damage.
ARTICLE | doi:10.20944/preprints202102.0516.v1
Subject: Environmental And Earth Sciences, Remote Sensing Keywords: machine learning; insect-damage; spectral data; theoretical model
Online: 23 February 2021 (14:12:28 CET)
In cotton cultivars, an insect that causes irreversible damage is the Spodoptera frugiperda, known as the fall armyworm. Since the visual detection of plants is a burdensome task for human inspection, the spectral information related to plant damage, registered on a spectral scale, can be useful. These measurements, associated with machine learning techniques, produce useful information for a rapid and non-invasive inspection method development. To contribute to this gap fulfillment, this paper proposes a machine learning framework to model the spectral response of cotton plants under the attack of the fall armyworm. Additionally, a theoretical model is presented, built from the results of the machine learning analysis, to infer this damage with up-to-date orbital sensors. The data was composed of the reflectance measurements collected at a cotton field with control plants and plants submitted to Spodoptera frugiperda damage. Their spectral response was recorded with a hand-held spectroradiometer ranging from 350 to 2,500 nm, for eight consecutive days. Different machine learning models were evaluated and the overall best model was defined by accuracies comparisons on a testing-set. A ranking approach was adopted based on the model accuracy, returning the most contributive wavelengths for the classification. Sequentially, an unsupervised neural network (Self-Organizing Map - SOM) was implemented to reduce data-dimensionality and assist in the definition of important spectral regions. The regions were associated with the spectral bands of the two sensors (OLI and MSI) and a theoretical model using a band simulation process with the overall best machine learning model was proposed. The results indicated that the Random Forest (RF) algorithm is the most suitable to predict cotton-plants damaged by insects and that the last day of analysis (8th day) was better to separate it, with F-measure equals 0.912. The ranking approach combined with the SOM method indicated the spectral regions at the red to near-infrared (650 to 1,350 nm) and shortwave infrared (1,570 to 1,640 nm) as the most important regions to the analysis. The proposed theoretical model simulated with the OLI and MSI sensor-bands returned an F-Measure of 0.865 and 0.886, respectively. In conclusion, this framework can be used to map cotton-plants under insect-attack. The theoretical model presents high accuracy to infer the insect-damaged on cotton plants based on multispectral bands from other sensors, being a useful tool for future research that intends to evaluate it in other areas and at different field scales.
ARTICLE | doi:10.20944/preprints202011.0534.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Digital Image Correlation; damage; self-heating; EPDM; fillers
Online: 20 November 2020 (10:32:54 CET)
The effect of the strain rate on damage in carbon black filled EPDM stretched during single and multiple uniaxial loading is investigated. This has been performed by analysing the stress-strain response, the evolution of damage by Digital Image Correlation (DIC), the associated dissipative heat source by InfraRed thermography (IR), and the chains network damage by swelling. The strain rates were selected to cover the transition from quasi-static to medium strain rate conditions. In single loading conditions, the increase of the strain rate yields in a preferential damage of the filler network while rubber network is preserved. Such damage is accompanied by a stress softening and an adiabatic heat source rise. Conversely, increasing the strain rate in cyclic loading conditions yields in a filler network accommodation and a high self-heating whose combined effect is proposed as a possible cause of the ability of filled EPDM to limit damage, by reducing cavities opening during loading and favoring cavities closing upon unloading.
ARTICLE | doi:10.20944/preprints202008.0357.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Striga infestation; Striga damage; yield loss; nitrogen application
Online: 17 August 2020 (10:08:51 CEST)
Low soil nitrogen status of savanna soils in Nigeria contributes to the persistent Striga hermonthica (Del.) Benth. infestation that limits maize production. The application of nitrogen fertilizer to Striga-resistant hybrids may reduce Striga infection and increase grain yields. This study assessed the performance of maize hybrids at low (30 kg ha-1) and high (120 kg ha-1) nitrogen application under natural infestation with Striga at Kafin Madaki and Tudun Wada in 2014 and 2015. Results showed that the application of nitrogen at 120 kg ha-1 reduced number of Striga plants by 59% compared to application at 30 kg N ha-1 in Kafin Madaki and by 21% in Tudun Wada. Compared to 30 kg N ha-1, the 120 kg N ha-1 rate also reduced Striga damage rating by 22% in Kafin Madaki and by 33% in Tudun Wada across the hybrids. Hybrids 8338-1 (5.3) and OBASUPER 1 (4.3) were the only entries with Striga damage rating greater than 4.5 (SDR > 4.5) when averaged across the nitrogen levels at both locations. Grain yield was 86 and 98% higher in Kafin Madaki and Tudun Wada, respectively when N was applied at 120 kg N ha-1 than at 30 kg N ha-1. The hybrids M1124-3 and M1227-14 produced grain yields that were significantly higher than those of the other hybrids in all locations. The hybrid 8338-1 produced the lowest grain yield across locations. Our results showed that, the application of 120 kg N ha-1 to Striga resistant maize hybrids will reduce Striga infection and increase grain yield.
ARTICLE | doi:10.20944/preprints202007.0343.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: protein; exercise; muscle damage; creatine kinase; myoglobin; inflammation
Online: 16 July 2020 (06:33:18 CEST)
This randomized trial compared pea protein, whey protein, and water-only supplementation on muscle damage, inflammation, delayed onset of muscle soreness (DOMS), and physical fitness test performance during a 5-day period after a 90-minute eccentric exercise bout in non-athletic, non-obese males (n=92, ages 18-55 years). The two protein sources (0.9 g protein/kg divided into three doses/day) were administered under double blind procedures. The eccentric exercise protocol induced significant muscle damage and soreness, and reduced bench press and 30-second Wingate performance. Whey protein supplementation significantly attenuated post-exercise blood levels for biomarkers of muscle damage compared to water-only, with large effect sizes for creatine kinase and myoglobin during the 4th and 5th days of recovery (Cohen's d >0.80); pea protein versus water supplementation had an intermediate, non-significant effect (Cohen's d <0.50); and no significant differences between whey and pea protein were found. Whey and pea protein compared to water supplementation had no significant effects on post-exercise DOMS and the fitness tests. In conclusion, high intake of whey protein for 5 days after intensive eccentric exercise mitigated efflux of muscle damage biomarkers, with intake of pea protein having an intermediate effect in part due to the 24% lower leucine amino acid content.
ARTICLE | doi:10.20944/preprints202001.0217.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: antioxidant; Nigella sativa; secondary metabolites; thymoquinone; DNA damage
Online: 19 January 2020 (14:33:58 CET)
Nigella sativa (NS) is an effective medicinal plant possessing noteworthy antioxidant property. In NS, there are more than hundred phyto-chemicals reported, out of which thymoquinone is the utmost active phyto-constituent having sturdy antioxidative property. Thymoquinone is a cyclicdione, when reacts with sodium azide, converts into α-azido ketones i.e its analogs which are handy with extensive range of reactions. Sodium azide induces stress in plants thereby, modulating the antioxidant system. The present investigation was planned to elucidate the effect of sodium azide at different concentrations (5µM, 10µM, 20µM, 50µM, 100µM and 200µM) on its secondary metabolites (mainly thymoquinone) in NS callus culture extract (NSE). The results showed sodium azide effect on thymoquinone content and a concentration dependent boost in antioxidant property. It was also observed that thymoquinone content and percent yield (analyzed by RP-HPLC; Reverse Phase- High Performance Liquid Chromatography) were minimum (0.033±0.006% and 0.420±0.045%, respectively) at 200 µM sodium azide used. Whereas, antioxidant activity (analyzed by DPPH; 2, 2-diphenyl-1-picrylhydrazyl) was found to be maximum (3.873±0.402%) at same dose. Further, analysis was done for inhibition of oxidative DNA damage at different concentrations of sodium azide on NSE, maximum inhibition of DNA damage (0.243±0.017%) was found at 200 µM concentration of sodium azide. When correlated, strong positive correlation was observed between percent yield and percent thymoquinone, antioxidant property and inhibition of DNA damage. Whereas, strong negative correlation was observed between percent yield and antioxidant property, percent thymoquinone and antioxidant property, percent thymoquinone and inhibition of DNA damage. The findings evidently point out that the content of thymoquinone, antioxidant property and inhibition of DNA damage was affected by sodium azide.
ARTICLE | doi:10.20944/preprints201812.0234.v1
Subject: Engineering, Civil Engineering Keywords: Steel; Tensile Test; XRCT; Damage Evolution; Gurson Model
Online: 19 December 2018 (12:14:27 CET)
This paper analyses the evolution of the internal damage in two types of steel that show different fracture behaviours, with one of them being the initial material used for manufacturing prestressing steel wires, which shows a flat fracture surface perpendicular to the loading direction, and the other one being a standard steel used in reinforced concrete structures, which shows the typical cup-cone surface. 3mm-diameter cylindrical specimens are tested with a tensile test carried out in several loading stages and, after each of them, unloaded and analysed with X-ray tomography, which allows detection of internal damage throughout the tensile test. In the steel used for reinforcement, damage is developed progressively in the whole specimen, as predicted by Gurson-type models, while in the steel used for manufacturing prestressing steel-wire damage is developed only in the very last part of the test. In addition to the experimental study, a numerical analysis is carried out by means of the finite element method by using a Gurson model to reproduce the material behaviour.
REVIEW | doi:10.20944/preprints201809.0422.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: LDL-oxidation; DNA-damage; antioxidant vitamins; oxidative stress
Online: 20 September 2018 (16:53:42 CEST)
Radical oxygen species formed in human tissue cells by many endogenous and exogenous pathways, cause extensive oxidative damage, which has been linked to various human diseases. This review paper provides an overview of lipid peroxidation and focuses on the free-radicals initiated processes of LDL oxidative modification and DNA oxidative damage, which are widely associated to the initiation and development of atherosclerosis and carcinogenesis, respectively. The article subsequently provides an overview of the recent human trials or even in vitro investigations on the potential of natural antioxidant compounds (such as carotenoids, vitamins C and E) to monitor LDL and DNA oxidative changes.
ARTICLE | doi:10.20944/preprints201807.0584.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: salt rock; creep; damage; fractional derivative; acoustic emission
Online: 30 July 2018 (11:15:31 CEST)
The use of salt rock for underground radioactive waste disposal facilities requires a comprehensive analysis of creep-damage process in salt rock. A computer-controlled creep setup is employed to carry out a creep test of salt rock lasted as long as 359 days under a constant uniaxial stress. The AE space-time evolution and energy releasing characteristics during creep test are studied in the meantime. A new creep-damage model is proposed on the basis of fractional derivative by combining the AE statistical regularity. It indicates that the AE data in non-decay creep process of salt rock can be divided into three stages. Furthermore, the parameters of new creep-damage model are determined by Quasi-Newton method. The fitting analysis suggests that the creep-damage model based on fractional derivative in this paper provides a precise description of full creep regions in salt rock.
ARTICLE | doi:10.20944/preprints201608.0011.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: curcumin; furazolidone; oxidative stress; DNA damage; mitochondrial pathway
Online: 2 August 2016 (05:59:38 CEST)
Furazolidone (FZD) is a synthetic nitrofuran with the antiprotozoal and antibacterial activity. The proper mechanism of FZD induced toxicity is still unclear. This study aimed to investigate the protective effect of curcumin on FZD induced oxidative stress, DNA injury and apoptosis in human hepatocyte L02 cells. The results showed that curcumin treatment significantly ameliorated FZD induced cytotoxicity, characterized by decreasing the production of reactive oxygen species (ROS) and malondialdehyde, as well as increasing superoxide dismutase, catalase activities and glutathione contents. Moreover, curcumin pretreatment significantly inhibited FZD induced the loss of mitochondrial membrane potential, the activation caspase-9 and -3 and apoptosis. Comet assay showed that curcumin attenuated FZD induced DNA injury in a dose-dependent manner. Correspondingly, curcumin markedly reversed the up-regulation of p53, Bax, caspase-9 and -3 mRNA expressions and the down-regulation of Bcl-2 mRNA (all p<0.05 or 0.01). These results reveal that curcumin protects against FZD induced oxidative stress, DNA injury and cell apoptosis via inhibiting oxidative stress and mitochondrial pathway, which may be attributed to ROS scavenging and anti-oxidative ability of curcumin. Importantly, our study highlights that curcumin may be a potential way to prevent FZD-mediated oxidative DNA injury and apoptosis in human or animals.
ARTICLE | doi:10.20944/preprints202311.1795.v1
Subject: Civil Engineering, Engineering Keywords: reinforced concrete beam; crack; damage evolution; finite element analysis
Online: 29 November 2023 (05:02:05 CET)
The insufficient toughness of concrete can lead to the occurrence of crack expansion, ultimately resulting in a decline in the physical and mechanical properties such as bearing capacity and deformation characteristics of structural components. In severe cases, this may lead to brittle failure, where the entire structure and system fail suddenly without significant deformation after being stressed. Additionally, during the process of shear and bending failure of reinforced concrete beams, the cracks generated on the side of the beam are mostly I-II composite cracks. Considering the material nonlinearity and geometric irregularity of reinforced concrete, it is of great significance to study the dynamic evolution law of crack expansion in reinforced concrete members. Based on experimental data, this paper aims to utilize the nonlinear finite element simulation software Abaqus to conduct finite element simulations of crack expansion in simple supported reinforced concrete beams. By accurately controlling the constitutive curves of concrete and reinforcement materials, the design of seismic performance of structural members can be enhanced, thereby making essential contributions to the preliminary analysis of actual crack control engineering. The nonlinear finite element results indicate that the joint cracks of the frame with the floor slab primarily manifest as flexural cracks, with the concrete damage degree of the floor slab being higher than that of the beam. This finding underscores the importance of considering the behavior of concrete and reinforcement materials in designing for seismic performance and crack control in actual engineering applications.
ARTICLE | doi:10.20944/preprints202311.1616.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: DNA replication; DNA damage; cell cycle checkpoints
Online: 24 November 2023 (16:29:38 CET)
Cells respond to DNA double-strand breaks by initiating DSB repair and ensuing a cell cycle checkpoint. The primary responder to DSB repair is non-homologous end joining, an error prone repair pathway. However, when DSBs are generated after DNA replication in the G2 phase of the cell cycle, a second DSB repair pathway, homologous recombination, can come into action. Both ATM and ATR are important for DSB-induced DSB repair and checkpoint responses. One method of ATM and ATR working together is through the DNA end-resection of DSBs. As a readout and marker of DNA end-resection, RPA is phosphorylated at Ser4/Ser8 of the N-terminus of RPA32 in response to DSBs. Here, the significance of RPA32 Ser4/Ser8 phosphorylation in response to DNA damage, specifically in S phase to G2 phase of the cell cycle is examined. RPA32 Ser4/Ser8 phosphorylation in G2 synchronized cells is necessary for increases in TopBP1 and Rad9 accumulation on chromatin and full activation of the ATR-dependent G2 checkpoint. In addition, our data suggest RPA Ser4/Ser8 phosphorylation modulates ATM-dependent KAP-1 phosphorylation and Rad51 chromatin loading in G2 cells.
ARTICLE | doi:10.20944/preprints202311.1278.v1
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: Acoustic Emission; Digital Image Correlation; Heat Exchanger; Damage Mechanism.
Online: 21 November 2023 (09:34:38 CET)
Aircraft heat exchangers play a crucial role in maintaining thermal balance and ensuring that essential components operate efficiently and safely. In this context, it is highly relevant to gain knowledge about the deterioration and the predominant damage mechanisms of these components. In this study, two different non-destructive methods are employed to analyze the damage initiation of a heat exchanger part during fatigue test. On the one hand, Acoustic Emission technique is employed using membrane-free microphones capable of capturing a broad bandwidth. The acoustic events were classified by a machine learning algorithm to determine their source and damage mechanisms. On the other side, Digital Image Correlation (DIC) allowed the measurement of the strain evolution along the test and more precisely, redistributions were considered as damage indicators. As a result, it was identified that AE served as early damage indicator as the cumulative number of events was in good agreement with the severity of the damage. With respect to classification two clear clusters ascribed to different type of events were identified. In the case of DIC, strain redistributions gave clear indications of damage or deterioration but at a later stage compared to AE
ARTICLE | doi:10.20944/preprints202310.0602.v2
Subject: Biology And Life Sciences, Aquatic Science Keywords: bifenthrin; Chinese giant salamander; RNAseq; oxidative stress; DNA damage
Online: 13 October 2023 (11:26:09 CEST)
Bifenthrin (BF) is a new highly effective broad-spectrum insecticide that has gained widespread use. However, there is limited research on the potential toxic effects of bifenthrin pollution on amphibians. In this research, Chinese giant salamanders (CGS) were exposed to three different concentrations of BF (0, 0.04, and 4 g/L BF) for 1-week to investigate the toxic effects. Behavioral changes, liver pathology, oxidative stress factors, DNA damage, and transcriptome differences were observed and analyzed. The results showed that exposure to BF (0.04 and 4) significantly decreased the adenosine-triphosphate (ATP), superoxide dismutase (SOD), glutathione (GSH), catalase (CAT), and 8-hydroxydeoxyguanosine (8-OHdG) contents in the brain, liver, and kidney of CGS, whereas the malondialdehyde (MDA) and reactive oxygen species (ROS) contents were increased. The liver tissue showed considerable inflammatory reactions and structural malformations. RNAseq analysis of the liver showed that BF caused abnormal antioxidant indices of CGS, which affected molecular function genes such as catalytic activity, ATP-dependent activity, metabolic processes, signaling and immune system processes, behavior and detoxification significantly up-regulated, resulting the differential genes were significantly enriched in calcium signaling pathway, PPARα signaling pathway and NF-kB signaling pathway. These results indicated that BF induced the abnormal production of free radicals to exceed the potential of the self-defense system, causing different degrees of oxidative damage and lipid peroxidation in the body, resulting in oxidative stress, abnormal lipid metabolism, DNA damage, tissue inflammation, and abnormal behavior. This work provides a theoretical basis for the rational use of pyrethrin and environmental risks assessment, and scientific guidance for the conservation of amphibian populations.
REVIEW | doi:10.20944/preprints202309.1932.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Anti-aging, DNA damage response, senescence-associated secretory phenotype
Online: 28 September 2023 (04:56:53 CEST)
Cellular aging has drawn the attention of researchers, scientists, and biotech businesses for the treatment of a number of medical conditions. Cellular aging is primarily defined by consistent cessation of proliferative development in response to internal and external stressors, including DNA damage, telomere shortening, mitochondrial dysfunction, and regulation of the senescence-associated secretory phenotype (SASP). Disturbances involving these factors may contribute to age-related disease development. Therefore, the current review aims to explore anti-aging factors targeting DNA damage response and SASP regulation and their detailed signaling networks. In addition, it provides an opportunity for researchers to identify not only anti-aging targets, but also anti-aging therapeutic strategies based on identified and non-identified targets.
REVIEW | doi:10.20944/preprints202308.0709.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: TLKs; DNA repair; HRR; NHEJ; replication; DNA damage; therapeutics
Online: 30 August 2023 (05:08:39 CEST)
DNA damage repair lies at the core of all cells’ survival strategy, including cancerous. Therefore, targeting such repair mechanisms forms the major goal of cancer therapeutics. The mechanism of DNA repair has been tousled with the discovery of multiple kinases. Recent studies on Tousled like Kinases have brought significant clarity on the effectors of these kinases which stands to regulate DSB repair. In addition to their well-established role in the DDR and cell cycle checkpoint mediation after DNA damage or inhibitors of replication, their suspected involvement in the actual DSB repair process has more recently been strengthened by the important finding that TLK1 phosphorylates RAD54 and regulates some of its activities and localization in the cell. Earlier findings of its regulation of RAD9 during checkpoint deactivation as well as defined steps during NHEJ ends processing were earlier hints of its important involvement broadly in DSB repair. All this has opened up new avenues to target cancer cells in combination therapy with genotoxins and TLK inhibitors.
ARTICLE | doi:10.20944/preprints202307.0551.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: pesticides; mining; chemical mixtures; selenium; hormesis; genetic damage; Colombia.
Online: 10 July 2023 (10:40:46 CEST)
The contexts where there is mining and agriculture activities are potential sources of risk to human health due to contamination by chemical mixtures. This study explored the association between the frequency of micronuclei and pesticides in regions with ferronickel (Montelibano, Córdoba) and gold (Nechí, Antioquia) mining, and a closed native mercury mine (Aranzazu, Caldas). A cross-sectional study was carried out with 247 residents in the mining regions. Sociodemographic, occupational, and toxicological variables were ascertained. Blood and urine samples were taken for pesticide analysis (12 organochlorines, organophosphates, and carbamates), 68 chemical elements were quantified in hair, and micronuclei (MN) were quantified in lymphocytes. The mixtures of chemical elements were grouped through exploratory factor analysis. Prevalence ratios (PR) were estimated with robust variance Poisson regressions to explore associations. The highest concentrations of chemical elements were in the active mines. The potentially most toxic chemical mixture was observed in the ferronickel mine. Pesticides were detected in a low proportion of participants. The frequency of MN was similar in the three mining contexts. There was great heterogeneity in the exposure to pesticides and chemical elements. The “hormetic effect” of selenium is described, in which at low doses it acts as a chelator and at high doses it can enhance the toxic effects of other elements. It is proposed that future studies in mining contexts include the measurement of chemical mixtures to better assess exposure and potential adverse health effects.
ARTICLE | doi:10.20944/preprints202306.2149.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: tomato homogenate; radiofrequency; dielectric heating; pasteurisation; inactivation; thermal damage
Online: 30 June 2023 (04:39:19 CEST)
Salmorejo is a homogenate based on tomato, olive oil and breadcrumbs commercialized as a “fresh-like” cold puree in Spain and other European countries. Salmorejo is thermolabile and requires pasteurising upon High Temperature, Short Time (HTST) conditions to inhibit microbes and enzymes. Due to its penetration, dielectric heating by radiofrequency (RF) might improve pasteurisation results of conventional heating (CH) in viscous products. The objective was to validate the pasteurisation temperature (70-100 °C, at 5 ºC intervals) for salmorejo processed by radiofrequency (operating at 27.12 MHz for 9.08 s) or conventional continuous heating. Salmorejo was prone to thermal damage upon HTST conditions. Main heat-induced changes include: orangeness, flavour homogenisation, loss of freshness, thickening, loss of vitamin C and lipid oxidation. A ‘fresh-like’ good quality salmorejo can be obtained using either conventional or radiofrequency pasteurisers. Both CH and RF equivalent treatments allowed a strong reduction of total and sporulated mesophilic microorganisms, and an adequate inhibition of the pectinmethylesterase, peroxidase and, to a lesser extent, polyphenoloxidase, but did not inhibit the polygalacturonase enzyme. Pasteurisation at 80 °C for 9.8 s (RF) or 10.9 s (CH) provided a good equilibrium in levels of microbiological and enzymatic inhibition and thermal damage to the product. Increasing this temperature does not improve enzyme inactivation levels and salmorejo may become overheated.
ARTICLE | doi:10.20944/preprints202201.0458.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: bypass cement dust; bioglass; FTIR; atomic displacement; radiation damage
Online: 31 January 2022 (12:50:44 CET)
Selected glasses with 10 Na2O + (90-x) P2O5 + x BCD where bypass cement dust (BCD) x value =10, 20, 30 in mol% were synthesized by recognizable melting annealing technique. Cooperative characterization of the prepared glasses were carried out through FTIR and SEM analysis before and after immersed in simulated body fluid (SBF) solution for 13 and 23 days at 37 oC. After immersion in SBF, apatite layer is produced on the glass surface after 13 day and increase after 23 day, showing good bioactivity after immersion in the SBF especially for bioglass sample with 30% BCD. A porous hydroxy apatite layer produced on the surface of SBF-glass composite and this layer became denser after more soaking time, periods were extended from 13 to 23 days. Atomic absorption spectroscopy explained the early period of soaking that cause release of both Si and Ca ions through the glass beside decreasing of phosphrous ions. Bioglass (BCD-30) is studied as shielding for gamma, protons and alphas by using Phy-X software, SRIM Monte Carlo simulation code and its subroutine TRIM. The gamma shielding parameters, mass stopping power (MSP), range for both proton (H- ions) and alpha (He- ions) in bioglass- BCD-30 and human bone tissue have estimated. Also, comparison between them is calculated in predicting the radiation damage and atomic displacements per atom (dpa).
ARTICLE | doi:10.20944/preprints202111.0192.v1
Subject: Social Sciences, Safety Research Keywords: rural village; earthquake; vulnerability index; vulnerability analysis; damage matrix
Online: 10 November 2021 (08:26:28 CET)
This study investigated and classified typical structures in rural village and analyzed the vulnerability of various typical types of structures. Based on the statistics of earthquake damages with magnitudes above 5 from 1996 to 2013 in China, the damage matrixes of different types of structures in rural village are obtained. And The vulnerability index and the vulnerability equation of structure are crucial to assess the earthquake losses of typical structures under different magnitudes earthquakes. According to the seismic loss of different types of structures under different earthquake magnitudes, there are possible to improve the seismic resilience of the buildings in rural village. Moreover, the regional vulnerability is analyzed by β probability distribution function, and the comprehensive seismic performance index of different types of agricultural buildings in the region is obtained. The main research is to predict the loss of different types of structures under different earthquake magnitudes in the future, and to provide technical support for different types of building in rural village reinforcement.
HYPOTHESIS | doi:10.20944/preprints202108.0454.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Alzheimer’s disease; DNA damage; somatic mutation; integrin; synaptic adhesion
Online: 23 August 2021 (14:34:00 CEST)
Alzheimer’s disease (AD) is a genetically complex senile neurodegeneration with unknown etiology. The first gene discovered to be mutated in early-onset AD, the amyloid precursor protein (APP), has been widely assumed as a causal factor in the disease cascade due to its generation of Aβ species. APP has an evolutionarily conserved biological role and activates a signaling program with notable similarities to integrin—a cell adhesion receptor with a wide array of functions. Intriguingly, several AD genome-wide association study (GWAS) candidate genes, including the SHARPIN locus recently reported by us and others, influence signaling of the integrin pathway. Integrins are focal adhesion regulators and serve in nervous system development, synaptic plasticity, and Tau phosphorylation. These observations suggest that the function of APP probably goes beyond Aβ generation in AD. Aging—the strongest risk factor for AD—is associated with various clock-like events in cells. For instance, neurons are continuously impacted by stochastic ‘hits’ to their genomes in aging, in the forms of DNA damage, insertion-deletions, copy-number variations (CNVs) and other types of somatic mutations. DNA damage and somatic mutations can result in neoplastic changes and cancer in mitotically active cells. However, their consequences in post-mitotic cells such as aging neurons are less defined. The current hypothesis holds that the stochastic loss of DNA sequence data at random loci in aging affects longer genes by chance more frequently. As a result, the biological processes coordinated by long genes may be more vulnerable to such random aging effects. Curiously, as shown by us and others, long genes are strongly enriched for synapse- and cell adhesion-related ontologies, more than any other biological process or cellular compartment. In addition, among various cell types, neurons possess the highest levels of long gene expression and are therefore more vulnerable to such harmful effects. The long gene vulnerability hypothesis provides a simple link between aging and the genetic landscape of AD and warrants new strategies for disease modification.
ARTICLE | doi:10.20944/preprints202106.0716.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: intracranial compliance; intracranial pressure; decompressive craniectomy; acute brain damage
Online: 29 June 2021 (23:58:09 CEST)
Background: Morphological alterations in intracranial pressure pulse waveform (ICPPW) secondary to intracranial hypertension (ICP >20 mmHg) and reduction in intracranial compliance (ICC) are well known indicators of neurological severity. To date, no studies have documented the ICPPW modifications after intracranial hypertension resolution with decompressive craniectomy (DC). The present study aimed to assess the morphological alterations in ICPPW among neurocritical care patients with and without DC, by comparing the variations of ICPPW features according to elevations in mean ICP values. Methods: Patients requiring ICP monitoring because of severe traumatic or spontaneous conditions were included. Mean ICP values were compared with ICPPW features (P2/P1 ratio, TTP and pulse amplitude). Elevation in ICP was produced by means of ultrasound-guided manual internal jugular veins compression. Results were distributed for three groups: intact skull (exclusive burr hole for ICP monitoring), craniotomy/large fractures (group 2) or DC (group 3). Results: 57 patients were analyzed. 21 (36%) presented no skull defects, whereas 15 (26%) had DC. ICP was not significantly different between groups: ±13.59 for intact and ±17.66 mmHg for DC, with ICP induced elevation also similar between groups (p= 0.56). Significant elevation was observed for P2/P1 ratio for groups 1 and 2, whereas reduction was observed in group 3 (elevation of ±0.09 for groups 1 and 2, whereas reduction of 0.03 for group 3, p=0.01). Conclusion: In the present study, intracranial pressure pulse waveform analysis indicated that intracranial compliance was significantly more impaired among decompressive craniectomy patients, although ICPPW indicated DC to be protective for further influences of ICP elevations over the brain. Analysis of ICPPW seems to be an alternative to real time ICC assessment.
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: galangin; Self microemulsion drug delivery system; Antioxidant damage; Pharmacokinetics
Online: 15 June 2021 (15:30:12 CEST)
Galangin(Gal) is a natural active flavonoid compound separated from the roots and rhizomes of Alpinia ofcinarum Hance. Modern pharmacological studies have shown that Gal has a variety of biological activities such as anti-tumor, anti-fungal, anti-bacterial, anti-inflammatory, anti-ischemic stroke, suppressing vitiligo and Alzheimer’s disease, etc. The purpose of this research was to prepare a galangin self-microemulsion drug delivery system (Gal-SMEDDS) and compare its anti-oxidant activity and pharmacokinetics with free Gal.The average particle size of the prepared Gal-SMEDDS was approximately 21.33 nm, the polydispersity index was 0.096, the zeta potential was -4.09 mV, and the entrapment efficiency was 96.74%. Compared with free Gal, the release of Gal-SMEDDS was improved in vitro release experiment. Cell experiments showed that Gal had obvious anti-oxidation effect, and the effect of Gal-SMEDDS was better than that of free Gal. In vivo pharmacokinetic experiments showed that the pharmacokinetic parameters of Gal-SMEDDS were better than that of free Gal, which indicated that the self-microemulsion drug delivery system(SMEDDS) effectively increases the oral bioavailability of Gal and alters its pharmacokinetic parameters, such that it may be effective in the treatment of anti-oxidant.
REVIEW | doi:10.20944/preprints202101.0525.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: DNA Damage; Base Excision Repair; SMUG1; 5-hmdU; Cancer
Online: 26 January 2021 (08:17:11 CET)
Single-stand selective monofunctional uracil DNA glycosylase 1 (SMUG1) works to remove uracil and certain oxidized bases from DNA during base excision repair (BER). This review provides a historical characterization of SMUG1 and 5-hydroxymethyl-2'-deoxyuridine (5-hmdU) one important substrate of this enzyme. Biochemical and structural analyses provide remarkable insight into the mechanism of this glycosylase revealing SMUG1 has a unique helical wedge which influences damage recognition during repair. Rodent studies suggest that, while SMUG1 shares substrate specificity with another uracil glycosylase UNG2, loss of SMUG1 can have unique cellular phenotypes. This review highlights the multiple roles SMUG1 may play in preserving genome stability, and how the loss of SMUG1 activity may promote cancer. Finally, we discuss recent studies indicating SMUG1 has moonlighting functions beyond BER, playing a critical role in RNA processing including the RNA component of telomerase.
ARTICLE | doi:10.20944/preprints202008.0005.v1
Subject: Biology And Life Sciences, Forestry Keywords: birch; chlorophyll; leaves’ damage; plants’ pathogens; roots; secondary metabolites
Online: 2 August 2020 (08:47:32 CEST)
The purpose of this study was to better understand the interactive impact of two soil-borne pathogens, Phytophthora cactorum (as the primary pathogen) and Armillaria gallica (as secondary), on two-year-old seedlings of silver birch (Betula pendula) subjected to stress caused by mechanical defoliation simulating primary insect feeding. One year after treatments, the chlorophyll fluorescence measurement and gas chromatography coupled with mass spectrometry (GC-MS) were used to analyze the photosynthetic activity in leaves, the volatile organic compounds (VOCs) emitted by birch leaves and chemical compounds from roots. Only the infection of roots by P. cactorum increased photosynthetic rates in the leaves, which may suggest its cryptic development in contrast to fungi. The birch leaves in seedlings exposed to 50% defoliation, inoculation with P. cactorum and A. gallica emitted more aromatic carbonyls and alcohols, as well as half as much aliphatic esters, compared to untreated controls. In infected birch roots, the production of phenols, triterpenes and fatty alcohols increased, but fatty acids decreased. This was the first experimental confirmation of the pathogenicity of P. cactorum on silver birch seedlings in Poland. The most severe damage to roots took place only in the case of two-way or three-way interactions. Higher levels of aromatic carbonyls and alcohols in leaves, as well as phenolic compounds in roots of stressed birches (compared to control) suggest an activation of plant systemic acquired resistance (SAR).
Subject: Medicine And Pharmacology, Pathology And Pathobiology Keywords: Epilepsy; Brain damage; Golgi determinations; Ramon y Cajal: axons
Online: 27 March 2020 (12:35:20 CET)
As a medical student (Granada University Medical School, Spain), interested in Pediatrics, expended countless hours at the hospital pediatric facilities and got to know many of the children and their medical problems. A particular case, still vivid on my mind, awaken my scientific curiosity. One day, walking and talking with a seven years old child he unexpectedly felt down unconscious with multiple, incontrollable and erratic muscular contractions involving face, body and extremities and salivating. I was overwhelmed thinking it was the child’ last hour. At the time, my knowledge of epilepsy was nil. Following the seizures, the child was up, talking and walking with me as if nothing has happened and without any knowledge of the event. What could have caused the brain motor cortex to suddenly discharge that amount of altered activity causing generalized and erratic muscular contractions remains inexplicable. I migrated to USA, become a Pediatric (Developmental) Pathologist and Director of the Pediatrics Autopsy Service (1962-1999) at the Dartmouth-Hitchcock Medical Center, New Hampshire. I carried out countless postmortem studied of children brains, normal (unaltered) as well as those altered by hemorrhagic, hypoxic-ischemic and/or traumatic damage. With an NIH Fellowship, I spend one year (1967-68) at the Cajal Institute (Madrid, Spain) studying Cajal’ old Golgi preparations and learning about the method. Some of my Golgi studies of children’ brains have been published: The Human Brain. Prenatal Development and Structure, Springer, Heidelberg, Germany, 2012. The present monograph explores the developmental neuropathology of selected perinatal cortical injuries through their acute, subacute and chronic stages. Including: a) how an altered neuronal activity evolves in a damaged cortical region; b) how it moves through the cortex (epileptic auras); and c) how it reaches the motor cortex to be discharged as erratic and incontrollable muscular contractions. Understanding these processes should provide insights into the pathogenesis of epilepsy secondary to perinatal brain damage.
ARTICLE | doi:10.20944/preprints201908.0074.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Heavy metals; Mining; Balochistan gerbil; liver injury; Kidney damage.
Online: 6 August 2019 (12:14:09 CEST)
Mining can impact the environment, biodiversity and human health through direct and indirect practices. This study investigated the effects of gold mining on Gerbillus nanus, pointing to organ dysfunction and redox imbalance. Soil samples, Lycium shawii and G. nanus were collected from a site near a mining planet and a control site. Soil and L. shawii samples from the mining site showed a significant increase cadmium (Cd), cupper (Cu), mercury (Hg), arsenic (As), zinc (Zn), lead (Pb) and vanadium (V). Hepatic, renal and pulmonary Cd, Pb, Hg, Zn, Cu, Fe, As and V concentrations were increased significantly in G. nanus at the mining site. Markers of liver and kidney function were elevated in serum, and several histological manifestations were demonstrated in liver, kidney and lung of G. nanus at the mining site. Malondialdehyde and nitric oxide were increased, and glutathione and antioxidant enzyme were declined in the liver and kidney of G. nanus. In conclusion, mining practices triggered tissue damage and oxidative stress in G. nanus living close to the mining site. These findings can represent the scientific basis for evaluating the environmental and health impact of mining in the on the nearby communities.
ARTICLE | doi:10.20944/preprints201809.0426.v1
Subject: Engineering, Marine Engineering Keywords: riser; vortex-induced vibration; fatigue damage prediction; empirical method
Online: 21 September 2018 (04:04:01 CEST)
To gain insight into riser motions and associated fatigue damage due to vortex-induced vibration (VIV), data loggers such as strain sensors and/or accelerometers are sometimes deployed on risers to monitor their motion in different current velocity conditions. Accurate reconstruction of the riser response and empirical estimation of fatigue damage rates over the entire riser length using measurements from a limited number of sensors can help in efficient utilization of the costly measurements recorded. Several different empirical procedures are described here for analysis of the VIV response of a long flexible cylinder subjected to uniform and sheared current profiles. The methods include weighted waveform analysis (WWA), proper orthogonal decomposition (POD), modal phase reconstruction (MPR), a modified WWA procedure, and a hybrid method which combines MPR and the modified WWA method. Fatigue damage rates estimated using these different empirical methods are compared and cross-validated against measurements. Detailed formulations for each method are presented and discussed with examples. Results suggest that all the empirical methods, despite different underlying assumptions in each of them, can be employed to estimate fatigue damage rates quite well from limited strain measurements.
ARTICLE | doi:10.20944/preprints201806.0131.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: histone demethylase inhibitors; DNA damage; epigenetic drugs; breast cancer
Online: 8 June 2018 (12:29:10 CEST)
Background: KDM5 enzymes are H3K4 specific histone demethylases involved in transcriptional regulation and DNA repair. These proteins are over-expressed in different kinds of cancer, including breast, prostate and bladder carcinoma, with positive effects on cancer proliferation and chemo-resistance. For these reasons, these enzymes are potential therapeutic cancer targets. Methods: In the present study, we analyzed the effects of three different inhibitors of KDM5 enzymes in MCF-7 breast cancer cells over-expressing JARID1B. In particular we tested H3K4 demethylation (western blot); target gene transcription (RNAseq and real time PCR); radio-sensitivity (citoxicity and clonogenic assays) and damage accumulation (kinetics of H2AX phosphorylation). Results: we show that two compounds with completely different chemical structure can selectively inhibit KDM5 enzymes and that both compounds are capable of increasing sensitivity of breast cancer cells to ionizing radiation and H2AX phosphorylation. Conclusions: These findings confirm the involvement of H3K4 specific demethylases in DNA damage signaling and repair and suggest new strategies for the therapeutic use of their inhibitors.
ARTICLE | doi:10.20944/preprints201708.0021.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: 3-((2-chlorobenzylidene)amino)coumarin; corrosion inhibitor; damage reduction
Online: 7 August 2017 (10:51:42 CEST)
New corrosion inhibitor derived from coumarin-3-amine namely 3-((2-chlorobenzylidene)amino)coumarin was synthesized and characterized by CHN elemental analysis in addition to Fourier transform infrared and nuclear magnetic resonance techniques. The anti-corrosion ability of 3-((2-chlorobenzylidene)amino)coumarin to inhibit the impacts of corrosion has been demonstrated and damage reduction of the mild steel also. 3-((2-chlorobenzylidene)amino)coumarin, has been employed as a good corrosion inhibitor for mild steel in HCL solution. The efficiency of the inhibition was figured according to weight loss method and it was 74.6%.
ARTICLE | doi:10.20944/preprints202308.1218.v1
Subject: Engineering, Mechanical Engineering Keywords: deformation; finite element method; mechanical damage; mechanical properties; numerical simulation.
Online: 17 August 2023 (09:45:57 CEST)
The flavor, aroma and color of coffee may change due to mechanical damage, reducing its qual-ity. To measure the mechanical response of materials, compression tests can be performed, de-termining the effect of force application on the mechanical behavior of the fruit at different stages of ripeness. In this context, this study aimed to analyze the deformation, strain energy and equivalent von Mises stress of coffee fruits at mature, semi-mature and immature maturation stages and compressed by collapse forces. Compression in three directions (x, y and z) was sim-ulated on coffee fruit models using the finite element method, with a compression support in the direction opposite to the force application axis. The numerical simulation of the compression process allowed to verify that the more mature the fruit, the greater the associated mean defor-mation (2.20 mm mm-1, 0.78 mm mm-1 and 0.88 mm mm-1), the lower the mean strain energy (0.07 mJ, 0.21 mJ and 0. 34 mJ) and the lower the mean equivalent von Mises stress (0.25 MPa, 1.03 MPa and 1.25 MPa), corresponding to ripe, semi-ripe and immature fruits; and these proper-ties may be used to analyze how processes in the production chain affect the amount of mechan-ical damage.
ARTICLE | doi:10.20944/preprints202308.0335.v1
Subject: Medicine And Pharmacology, Complementary And Alternative Medicine Keywords: Mexican stingless bee; propolis; antimicotic activity; structural damage; Malassezia pachydermatis
Online: 3 August 2023 (10:28:37 CEST)
This work demonstrates the antimycotic activity and structural damage of stingless bee propolis against Malassezia pachydermatis,causative agent of canine otitis.Two propolis ethanolic extracts(EEP) derived from the stingless bees, Scaptotrigona mexicana and Tetragonisca angustula were tested against three clinical strains of Malassezia pachydermatis and one of reference (ATCC 14522). Each ethanolic extract of propolis was analyzed by Gas Chromatography – Mass Spectrometry(GC-MS). Antimycotic activity was evaluated by plate microdilution. To evaluate the induced changes in yeasts, by fluorescence microscopy, stains were performed with chalcofluor white and propidium iodide. For both propolis, sesquiterpenes were the main components determined by GC-MS. Minimum inhibitory concentration (MIC) of 32 mg/mL and a minimum fungicidal concentration of 64 mg/Ml were determined in both extracts. EPP of Scaptotrigona mexicana and Tetragonisca angustula caused significant damage to yeast morphology. Propidium iodide penetration was observed, indicating damage to the yeast and with calcofluor-white stain, only morphology deformation was observed..The antimycotic activity and structural damage of propolis from Scaptotrigona mexicana and Tetragonisca angustula against Malassezia pachydermtais was demonstrated .This probably being the first scientific report that demonstrates structural damage in Malassezia pachydermatis of Mexican stingless bee propolis
ARTICLE | doi:10.20944/preprints202308.0154.v1
Subject: Engineering, Mechanical Engineering Keywords: Radio Telescope; Azimuth Wheel-Rail; Surface Damage; Electromagnetic Ultrasonic Testing
Online: 2 August 2023 (10:05:35 CEST)
The azimuth wheel-rail of large aperture radio telescope is the key component, it not only sup-ports the whole weight of the antenna, but also directly affects the pointing performance of the antenna with its surface accuracy. The whole weight of the radio telescope is hundreds or even thousands of tons, its azimuth frame rollers have great contact stress with the wheel-rail surface, repeated rolling can cause rolling contact fatigue on the wheel-rail surface, resulting in wear, cracks and other damage to the wheel-rail, and even lead to failure or fracture of the wheel-rail in serious cases, so it is very important to monitor the damage of the antenna wheel-rail. In order to visually detect the use of antenna wheel-rail surface, this paper proposed the method using electromagnetic ultrasonic detection to detect the damage of antenna wheel-rail surface for the first time. Based on the electromagnetic ultrasonic nondestructive testing principle, the simplified wheel-rail model containing wear, corrosion and crack damage is simulated. The results show that this method can effectively detect the surface damage of the antenna wheel-rail surface, and it can provide an important reference for the research of wheel-rail damage detection of large radio telescope.
ARTICLE | doi:10.20944/preprints202306.0656.v1
Subject: Engineering, Mining And Mineral Processing Keywords: rockburst; true triaxial; numerical simulation; static-dynamic loads; damage evolution
Online: 9 June 2023 (03:51:39 CEST)
The damage evolution rules of coal under true triaxial combined static-dynamic loads are important to understand and reveal the mechanism of rockburst in coal mines. The numerical simulation was carried out using FLAC3D to explore the coupling effect of static and dynamic stress, especially the influence of dynamic load parameters. The results show that the increase of dynamic load amplitude not only makes the plastic zone grow exponentially and shorten the damage development time, but also decreases the residual strength of the coal sample, which leads to a much more violent of the dynamic failure. The stress wave can propagate more stable in the coal sample with the increase of dynamic load frequency and the development time of the plastic zone also show synchronous fluctuating features, and when the frequency is like the intrinsic frequency of the coal sample, the dynamic load has a significant stimulate effect. The static and dynamic loads have different damage effect to the coal sample under true triaxial stress path, the weight decreases in order of the minimum principal stress, the maximum principal, the amplitude of the dynamic load and at last the dynamic stress frequency by the entropy weight method analysis.
ARTICLE | doi:10.20944/preprints202306.0025.v1
Subject: Engineering, Civil Engineering Keywords: ANN; FEM; damage assessment; structural health monitoring; steel truss bridge
Online: 1 June 2023 (04:38:41 CEST)
Damage assessment is one of the most crucial issues for bridge engineers, especially for existing steel bridges. Among several methodologies, the vibration measurement test is a typical approach in which the natural frequency variation of the structure is monitored to detect the existence of damage. However, locating and quantifying the damage is still a big challenge. In this regard, the artificial intelligence (AI)-based approach seems a potential way to accomplish those obstacles. This study deploys a comprehensive campaign to determine all dynamic parameters of a pre-damage steel truss bridge structure. Based on the results of mode shape, natural frequency, and damping ratio, a finite element model (FEM) is created and keeps updating. The artificial intelligence network's input data will be analyzed and evaluation from damage cases. The trained artificial neural network model will be curated and evaluated to confirm the approach's feasibility. During the actual operational stage of the steel truss bridge, this damage assessment system is showing good performance in terms of monitoring the structural behavior of the bridge under some unexpected accidents.
ARTICLE | doi:10.20944/preprints202305.1200.v1
Subject: Medicine And Pharmacology, Pulmonary And Respiratory Medicine Keywords: Histones; COPD; HDAC; H3.3; Inflammation; Hyperacetylations; Cytotoxicity; Alveolar damage; Cytokines.
Online: 17 May 2023 (05:46:03 CEST)
Excessive extracellular histones can damage cells despite their importance in DNA structure and gene regulation. We previously showed the harmful effect of histone 3.3 (H3.3) and its acetylated form (AcH3.3) in chronic obstructive pulmonary disease (COPD), but further research is needed to understand the in vivo underlying mechanisms. To investigate this, we administered a single dose of recombinant histones via intra-tracheal instillation in C57BL/6 mice and analyzed the outcomes after 48 hours. Both rH3.3 and rAcH3.3 effectively reached the bronchial and alveolar space. Lung histology revealed severe immune cell infiltration, rupture, damage, and thickening of many alveolar walls. Micro-CT scans showed macroscopic structure changes with a decreased tissue volume to total volume ratio. The administration of rH3.3 and rAcH3.3 induced lung apoptotic activity, as indicated by increased levels of cleavage caspase 3 and 9. Moreover, elevated plasma levels of pro-inflammatory cell mediators, including TNF-alpha, IL-6, MCP-3, and CXCL-1, were observed. The pathological changes and pro-inflammatory cytokine response were more pronounced in animals treated with rAcH3.3, which also exhibited leukocytosis and lymphocytosis. These findings emphasize the crucial role of extracellular H3.3 acetylation in inducing cytotoxicity and a robust, acute inflammatory response similar to what occurs in the lungs of COPD patients.
ARTICLE | doi:10.20944/preprints202302.0472.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Flax; Flexural behavior; Damage behavior; Acoustic Emission; Digital Image Correlation
Online: 27 February 2023 (10:13:53 CET)
Understanding the effect of staking sequences and identifying the damage occurring within a structure using a structural health monitoring system are the keys to an efficient design of composite-based parts. In this research, a combination of digital image correlation (DIC) and acoustic emission (AE) is used to locate and classify the type of damage depending on the stacking sequence of the laminate during flexural loading. A comparison of the strain field results for unidirectional, cross-ply, and quasi-isotropic laminates was made in a first attempt to discuss their global behavior and to correlate the different damage patterns with the possible failure mechanisms. The damage was then addressed using a comprehensive interpretation of the acoustic emission signatures using the K-means classification of the acoustic events. The development of each damage mechanism was correlated to the applied load and expressed as a function of the loading rate to highlight the effect of the stacking sequence. Finally, the results of DIC and AE were combined to improve the reliability of the damage investigation without limiting the failure mechanism to matrix cracking, interfacial failure, and fiber breakage, as expected by the unsupervised event clustering.
REVIEW | doi:10.20944/preprints202207.0078.v2
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Extracellular vesicles; neurodegenerative disorders; mitochondrial damage-associated molecular patterns; inflammation
Online: 6 July 2022 (09:16:21 CEST)
Neuroinflammation is a common hallmark in different neurodegenerative conditions that share neuronal dysfunction and a progressive loss of a selectively vulnerable brain cell population. Alongside ageing and genetics, inflammation, oxidative stress, and mitochondrial dysfunction are considered key risk factors. Microglia are considered immune sentinels of the central nervous system capable of initiating an innate and adaptive immune response. Nevertheless, the pathological mechanisms underlying the initiation and spread of inflammation in the brain are still poorly described. Recently, a new mechanism of intercellular signalling mediated by small extracellular vesicles (EVs) has been identified. EVs are nanosized particles (30-150 nm) with a bilipid membrane that carries cell-specific bioactive cargos that participate in physiological or pathological processes. Damage-associated molecular patterns (DAMPs) are cellular components recognized by the immune receptors of microglia, inducing or aggravating neuroinflammation in neurodegenerative disorders. Diverse evidence links mitochondrial dysfunction and inflammation mediated by mitochondrial-DAMPs (mtDAMPs) such as mitochondrial DNA, TFAM and cardiolipin, among others. Mitochondrial-derived vesicles (MDVs) are a subtype of EVs produced after mild damage to mitochondria and, upon fusion with multivesicular bodies (MVBs), are released as EVs to the extracellular space. MDVs are particularly enriched in mtDAMPs which can induce an immune response and the release of pro-inflammatory cytokines. Importantly, growing evidence supports the association between mitochondrial dysfunction, EVs release and inflammation. Here, we describe the role of extracellular vesicles-associated mtDAMPS in physiological conditions and as neuroinflammation activators contributing to neurodegenerative disorders.
ARTICLE | doi:10.20944/preprints202204.0240.v1
Subject: Engineering, Civil Engineering Keywords: Deep Learning; Aerial photo; Typhoon Faxai; roof damage; detection; classification
Online: 26 April 2022 (10:58:36 CEST)
Following the occurrence of a typhoon, quick damage assessment related to residents can facilitate quick dispatch of house repair and disaster insurance works. Employing a deep learning method, this study used aerial photos of the Chiba prefecture obtained following the Typhoon Faxai in 2019 to automatically detect and evaluate the roof damage. This study comprised three parts: training deep learning model, detecting the roof damage using trained model, and classifying the level of roof damage. The detection object comprised roof outline, blue tarps, and roof completely destroyed. The roofs were divided into three categories: roof without damage, roof with blue tarps and roof completely destroyed. the F value obtained using the proposed method was higher than those obtained using other methods. In addition, it can be further divided into 5 levels from level 0 to 4. Finally, the spatial distribution of the roof damage was analyzed using ArcGIS tools. The proposed method is expected to provide certain reference for the real-time detection of the roof damage after the occurrence of a typhoon.
ARTICLE | doi:10.20944/preprints202202.0297.v1
Subject: Biology And Life Sciences, Virology Keywords: miRNA; mRNA; HIV; network; bioinformatics; HAND; viral infection; CNS damage
Online: 23 February 2022 (14:13:59 CET)
HIV-associated neurocognitive disorder (HAND) is an array of neurocognitive changes associated with HIV infection, and the roles of microRNAs in HAND are not completely revealed yet. Based on published data and publicly available databases, we constructed an integrated miRNA-mRNA network involved in HAND. Bioinformatics analyses, including gene ontology, network analysis, and KEGG pathway analysis, were applied for further study of the network and the genes of the network. The axon guidance KEGG pathway, three genes NTNG1, EFNB2, CXCL12, and 17 miRNAs which regulates them, are spotlighted in our study. This study provides new perspectives to the knowledge of miRNAs’ roles in the process of HAND, and our findings provided potential therapeutic targets and clues of HAND.
ARTICLE | doi:10.20944/preprints202012.0175.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: fruit transport; mechanical damage; physiological disorders; fruit maturity; colour; firmness
Online: 7 December 2020 (16:00:33 CET)
The study assessed the changes in the quality and physical and chemical parameters of apples of four cultivars (‘Gala’, ‘Idared’, ‘Topaz’, ‘Red Prince’) subjected to mechanical vibrations during transport under model conditions and after storage (shelf-life). Quality changes in apples were evaluated based on skin and flesh colour, total soluble solids, dry matter, firmness, titratable acidity, pH value, total polyphenol content and antioxidant capacity. The applied vibrations at a frequency of 28 Hz caused changes in the above parameters, which were visible also after storage and depended on cultivar, but did not show any clear trend or direction. Skin colour varied whereas flesh colour remained stable. Vibrations resulted in a decrease in firmness. The greatest stability of quality parameters, the highest content of bioactive compounds and the highest antioxidant capacity were observed for ‘Red Prince’ and ‘Topaz’ apples – this refers to the control and treated samples before and after storage. However, total polyphenol content and antioxidant capacity increased in all studied cultivars as a result of vibrations and storage, which suggests that 28 Hz mechanical vibrations and short-term cold storage did not reduce the health promoting potential of the apples.
ARTICLE | doi:10.20944/preprints201912.0295.v3
Subject: Chemistry And Materials Science, Polymers And Plastics Keywords: damage and defect assessment; magnetic resonance imaging; polymer matrix composite
Online: 4 November 2020 (10:17:19 CET)
Defectively manufactured and deliberately damaged composite laminates fabricated with different continuous reinforcing fibres (respectively, carbon and glass) and polymer matrices (respectively, thermoset and thermoplastic) were inspected in magnetic resonance imaging equipment. Two pulse sequences were evaluated during non-destructive examination conducted in saline solution-immersed samples to simulate load-bearing orthopaedic implants permanently in contact with biofluids. The orientation, positioning, shape, and especially the size of translaminar and delamination fractures were determined according to stringent structural assessment criteria. The spatial distribution, shape, and contours of water-filled voids were sufficiently delineated to infer the amount of absorbed water if thinner image slices than this study were used. The surface texture of composite specimens featuring roughness, waviness, indentation, crushing, and scratches was outlined, with fortuitous artefacts not impairing the image quality and interpretation. Low electromagnetic shielding glass fibres delivered the highest, while electrically conductive carbon fibres produced the poorest quality images, particularly when blended with thermoplastic polymer, though reliable image interpretation was still attainable.
ARTICLE | doi:10.20944/preprints202005.0012.v1
Subject: Engineering, Civil Engineering Keywords: cylindrical latticed shell; damage accumulation; progressive collapse; Finite Element; earthquake
Online: 2 May 2020 (13:22:42 CEST)
In this paper, the results of finite element analyses of a single-layer cylindrical latticed shell under severe earthquake is presented. A 3D Finite Element model using fiber beam elements were used to investigate the collapse mechanism of this type of shell. The failure criteria of structural members are simulated based on the theory of damage accumulation. Severe earthquake of peak ground acceleration (PGA) of 500 gal was applied to the shell. The stress and defeomation of the shell were studied in detail. A three-stages collapse mechanism “double-diagonal -members-failure-belt” of this type of structure was discovered. Based on the analysis results, the measures to mitigate collapse of this type of structure is recomanded.
ARTICLE | doi:10.20944/preprints202001.0225.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: radar remote sensing; building damage assessment; change detection method; GLCM
Online: 20 January 2020 (10:19:38 CET)
In this research paper, change detection based methods were considered to find collapsed and intact buildings using radar remote sensing data or radar imageries. Main task of this research paper is collection of most relevant scientific research in field of building damage assessment using radar remote sensing data. Several methods are selected and presented as best methods in present time, there are methods with using interferometric coherence, backscattering coefficients in different spatial resolution. In conclusion, methods are given in end, which show, which methods and radar remote sensing data give more accuracy and more available for building damage assessment. Low resolution Sentinel-1A/B radar remote sensing data are recomended as free available for monitoring of destruction degree in microdistrict level. Change detection and texture based method are used together to increase overall accuracy. Homogeneity and Dissimilarity GLCM texture parameters found as better for separation of a collapsed and intact buildings. Dual polarization (VV,VH) backscattering coefficients and coherence coefficients (before earthquake and coseismic) were fully utilized for this study. There were defined the better multi variable for supervised classification of none building, damaged and intact buildings features in urban areas. In this work, we were achieved overall accuracy 0.77, producer’s accuracy for none building is 0.84, for damaged building case 0.85, for intact building 0.64. Amatrice town was chosen as most damaged from 2016 Central Italy Earthquake.
ARTICLE | doi:10.20944/preprints201910.0052.v1
Subject: Physical Sciences, Optics And Photonics Keywords: 3D laser lithography; laser induced damage threshold; micro-optics; photonics
Online: 4 October 2019 (11:56:36 CEST)
Direct laser writing based on non-linear 3D nanolithography (also known as 3D laser lithography, 3DLL) is a powerful technology to manufacture polymeric micro-optical components. However, practical applications of these elements are limited due to the lack of knowledge of their optical resilience and durability. In this work, we employ 3DLL for the fabrication of bulk (i.e. fully filled) and woodpile structures out of different photopolymers. We then characterize them using S-on-1 laser induced damage threshold (LIDT) measurements. In this way, quantitative data of LIDT values can be collected. Furthermore, this method permits to gather damage morphologies. The results presented in this work demonstrate that LIDT values depend on the material and the geometry of the structure. Bulk non-photosensitized hybrid organic-inorganic photopolymer SZ2080 structures are found to be the most resilient with a damage threshold being of 169±15 mJ/cm2.
ARTICLE | doi:10.20944/preprints201811.0102.v1
Subject: Biology And Life Sciences, Aging Keywords: aryl hydrocarbon receptor; DNA damage; single nucleotide polymorphisms; BCL6; lymphoma
Online: 5 November 2018 (10:28:08 CET)
1) Background: We tested whether AHR activation induces DNA damage, whether polymorphisms in genes related to risk of Non-Hodgkin lymphoma are associated with DNA damage, and whether the two conditions do interact with each other. 2) Methods: Our study population included 36 subjects, randomly selected among the population controls participating in a case-control study on lymphoma in Sardinia, Italy, who donated a blood sample. We investigated 47 single nucleotide polymorphisms (SNPs) previously reported to convey risk of lymphoma; the Dual-Glo® Luciferase Assay System to detect activation of the aryl hydrocarbon receptor (AhR) by the serum of study subjects; and the COMET Assay to detect DNA damage. 3) Results: Activation of the aryl hydrocarbon receptor did not increase DNA damage in our study population. On the other hand, the mutant allele (G) of rs1056932/BCL6 increased the occurrence of DNA damage (p = 0.045); such association was confirmed among AhR negative, but not AhR positive subjects. 4) Conclusions: We observed excess DNA damage associated with a gene polymorphism, namely rs1056932/ BCL6, previously reported in association with risk of lymphoma. No increase in DNA damage was associated with AhR activation per se, nor with the other gene polymorphisms we investigated.
ARTICLE | doi:10.20944/preprints201810.0359.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: oxidative damage; organophosphates; neurotoxicity; spatial working memory; anxiety-related behaviors
Online: 16 October 2018 (12:04:13 CEST)
The mechanization of agricultural activities has led to indiscriminate deposition of toxic xenobiotics, including organophosphates in the biomes, and this has led to intoxication characterized with deleterious oxidative and neuronal changes. This study investigated the consequences of oxidative and neurogenic disruptions that follow exposure to two organophosphates, chlorpyrifos (CPF) and dichlorvos (DDVP) on neuro-cognitive performance and anxiety-like behaviors in rats Thirty-two adult male Wistar rats (150 – 170g) were randomly divided into 4 groups, orally exposed to normal saline (NS), DDVP (8.8mg/kg), CPF (14.9mg/kg) and DDVP+CPF for 14 consecutive days. On day 10 of exposures, anxiety-like behaviors and amygdala dependent fear learning were assessed using Open Field and Elevated Plus Maze paradigms respectively, while spatial working memory was assessed on day 14 in the Morris water maze paradigm, following 3 training trials each on days 11, 12 and 13. On day 15, the rats were euthanized, and their brains excised, hippocampus and amygdala removed, 5 of which were homogenized and centrifuged to analyze nitric oxide (NO) metabolites, total reactive oxygen species (ROS), and acetylcholinesterase (AChE) activity, and the other three processed for histology (cresyl violet stain) and proliferative marker (Ki67 immunohistochemistry). Marked (p≤0.05) loss in body weight, AChE depletion, and overproduction of both NO and ROS were observed after repeated exposure to individual and combined doses of CPF and DDVP. Insults from DDVP exposure appeared more severe owing to the observed greater losses in the body weights of exposed rats. There was also a significant (p≤0.05) effect on the cognitive behaviors recorded from the exposed rats, and these deficits were related to the oxidative damage and neurogenic cell loss in the hippocampus and the amygdala of the exposed rats. Taken together, these results provided an insight that oxidative and neurogenic damages are central to the severity of neuro-cognitive dysfunction and increased anxiety-like behaviors that follow organophosphate poisoning.
ARTICLE | doi:10.20944/preprints201809.0382.v1
Subject: Biology And Life Sciences, Forestry Keywords: forest road surface; forest road damage; vibration measurements; vibration software
Online: 19 September 2018 (10:43:25 CEST)
Regarding number of vehicles, forest roads are characterized by low traffic intensity, but on the other hand great values of ground pressure between wheels of timber truck units and forest road surface occur, often with pressures values above 80 kN which additionally causes damage of the upper and lower forest road layer. There are currently several methods for assessing condition of a forest road surface which are mainly used for assessing state of public roads, but can be used in forestry as well. Assessing condition of forest road surface was done by measuring vibrations with a specially developed software for Android OS installed on a Huawei MediaPad 7 Lite. Software measured vibrations in all three axes, coordinates of device, speed of the vehicle and time. Aim of this research was to determine accuracy of collected data so that this method can be used for scientific and practical purposes. Research was carried out on the segment of a forest road during driving a vehicle equipped with a measuring device. Tests were performed in both driving direction of the forest road segment with different measuring frequencies, tyre inflation pressures and driving speeds. Values of vibrations were classified and translated on a map of forest road together with devices’ measured coordinates. Vibration values were compared with places of recorded forest road surface damages. Research results show no significant difference in vibration values between 1 Hz and 10 Hz of measurement frequencies. Based on the analysis of collected data and obtained results, it is clear that it is possible to assess the condition of a forest road surface by measuring vibrations. The greatest values of vibrations were recorded on the most damaged parts of the forest road. Vibrations do not depend on tyre inflation pressure, but ranges of vibrations are decreasing with decreasing driving speed. Accuracy of collected data depends on GPS signal quality, so it is recommended that each segment of forest road is recorded twice so that location of damages on forest road can be confirmed with certainty.
ARTICLE | doi:10.20944/preprints201710.0182.v1
Subject: Engineering, Mechanical Engineering Keywords: very high cycle fatigue; fatigue pre-damage; titanium alloy; LCF
Online: 30 October 2017 (10:22:24 CET)
The effect of low cycle fatigue (LCF) pre-damage on the subsequent very high cycle fatigue (VHCF) behavior is investigated in TC21 titanium alloy. LCF pre-damage is applied under 1.8% strain amplitude up to various fractions of the expected life and subsequent VHCF properties are determined using ultrasonic fatigue tests. Results show that 5% of LCF pre-damage insignificantly affects the VHCF limit due to the absent of pre-crack, but decreases the subsequent fatigue crack initiation life estimated by Pairs’ law. Pre-cracks introduced by 10% and 20% of LCF pre-damage significantly reduce the subsequent VHCF limits. The crack initiation site shifts from subsurface-induced fracture for undamaged and 5% of LCF pre-damage specimens to surface pre-crack for 10% and 20% of LCF pre-damage specimens in very high cycle region. The fracture mechanism analysis indicate that LCF pre-crack will re-start to propagate under subsequently low stress amplitude when stress intensity factor of pre-crack is larger than its threshold. Furthermore, the predicted fatigue limits based on EI Haddad model for the LCF pre-damage specimens well agree with the experimental results.
ARTICLE | doi:10.20944/preprints201608.0055.v1
Subject: Environmental And Earth Sciences, Remote Sensing Keywords: seismic damage building; watershed segmentation; SAR; texture feature; change detection
Online: 5 August 2016 (12:19:24 CEST)
The information of seismic damage of buildings in SAR images of different time phase, especially in SAR images after earthquake, is easily disturbed by other factors, which affects the accuracy of information discrimination. In order to identify and evaluate the distribution information of the seismic damage accurately and make full use of the abundant texture features in the SAR image. The conventional method of change detection based on texture features usually takes the pixel as the calculating unit. In this paper, a method of texture feature change detection of SAR images based on watershed segmentation algorithm is proposed. Based on the optimization of texture feature parameters, the feature parameters are segmented by the watershed segmentation algorithm, and the feature object image is obtained. This method introduces the idea of object oriented, and carries out the calculation of the difference map at the object level, Finally, the classification threshold value of different types of seismic damage types is selected, and the recognition of building damage is achieved. Taking the ALOS data before and after the earthquake in Yushu as an example to verify the effectiveness of the method, the overall accuracy of the building extraction is 88.9%, Compared with pixel-based methods, it is proved that the proposed method is effective.
ARTICLE | doi:10.20944/preprints202311.0136.v1
Subject: Engineering, Aerospace Engineering Keywords: Open hole tensile test; Hybrid composite; Damage mechanism; Hole diameter; SEM
Online: 2 November 2023 (09:10:47 CET)
The open hole tensile and flexural test of composites holds immense importance in aerospace and structural engineering. These tests provide critical insights into how composites perform under real-world conditions, allowing for the development of materials that meet rigorous standards, thereby ensuring the safety and durability of aircraft and other applications. This study investigates the influence of hole size on the open hole tensile (OHT) and flexural properties (OHF) of plane woven aramid/epoxy (AFRP), basalt/epoxy (BFRP), and aramid-basalt/epoxy (ABFRP) sandwiched laminates. Specimens with three different hole sizes viz., 4 mm, 6 mm, 8 mm were prepared and tested according to ASTM D5766 and ASTM D7264 for OHT and OHF performance respectively. Results indicated that the hybridization of aramid-basalt layers in a sandwich lay up significantly improved the mechanical performance when compared to only aramid laminate. However, with the increase in hole size the mechanical properties declined irrespective of the material. Basalt fibres showed higher hole sensitivity under tensile loading due to its brittle fracture mechanism while aramid fibres exhibited higher hole sensitivity under flexural loading which can be attributed to its the poor compressive strength. The effect of hole size on the damage mechanism has also been highlighted through scanning electron microscope (SEM). Major failure modes observed are delamination around the hole edges, ductile and brittle fibre fractures, and delamination.
COMMUNICATION | doi:10.20944/preprints202309.2156.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: stem cells; DNA-damage; precancerous cell state; repair; genome reprograming; carcinogenesids
Online: 30 September 2023 (07:58:52 CEST)
Recent successes in the field of evolutionary cancer cell biology (ECCB) have brought to a head two of the most important controversies regarding cancer origin. The first concerns the question of whether carcinogenesis is initiated only by genetic alterations, mutations, and driver genes, as the mutational theory teaches. The ECCB, claims that a large number of polyploidy-related cancers (PGCC cancers) are not due to mutations, but rather to inadequate ancient repair mechanisms used by DNA-damaged stem cells for their repair. Somatic mutations are merely secondary. The second controversy, described in the previous article, concerns the non-mutational theory itself: Are non-mutational polyploid cancers an atavism - as previously thought - or rather the effect of an ancient gene regulatory network aGRN that controls genome reprogramming in precancerous DNA-damaged cells as well in the transformed cells. Finally, the unicellular gene module of cancer, of which the aGRN is a part, has evolved along with the multicellular genome during the last 1000 My of evolution. and non-mutated cancer cell systems are under the control of the aGRN. The atavistic theory relies on phylostratigraphic evidence to determine the age of cancer genes. It states that most cancer-like genes arose during the transition period from unicellularity to multicellularity, but also during the early metazoan era. In our opinion, the atavistic theory is flawed and suffers from many misunderstandings. It provides little insight into the origin and coevolution of the cancer cell system and its control by the ancient gene regulatory network aGRN.
REVIEW | doi:10.20944/preprints202307.0327.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Brainstem auditory evoked potentials; microvascular decompression; hemifacial spasm; vestibulocochlear nerve damage
Online: 6 July 2023 (03:41:17 CEST)
Brainstem auditory evoked potentials (BAEPs) testing is very important when microvascular decompression (MVD) is performed with hemifacial spasm (HFS). The reason for this is that the vestibulocochlear nerve is located right next to the facial nerve, so the vestibulocochlear nerve may be affected by manipulation by surgery. The BAEPs test method for detecting vestibulocochlear nerve damage during surgery has been developed a lot and is helping a lot during surgery. In most HFS patients with normal vestibulocochlear nerve, the degree of vestibulocochlear nerve damage caused by surgery is reflected very well in the BAEPs test waveforms. Therefore, a real time test is the best way to minimize the damage to the vestibulocochlear nerve. The purpose of this study was to review the most recently published BAEPs test used in MVD surgery and to find out in detail the relationship between the vestibulocochlear nerve damage and the BAEPs waveforms.
ARTICLE | doi:10.20944/preprints202307.0259.v1
Subject: Engineering, Marine Engineering Keywords: PMMA; J-C constitutive Model; Impact; Loss and Damage; Numerical Simulation
Online: 5 July 2023 (08:50:16 CEST)
Polymethyl methacrylate (PMMA) polymer is widely used in various fields today. In order to thoroughly reveal the structural impact performance of PMMA materials, this paper is based on the comprehensive Johnson-Cook constitutive model and damage failure model, and accurately confirm the J-C constitutive and damage failure model parameters of PMMA through material test data, The dynamic process of steel bullet impacting PMMA plate structure is analyzed by finite element software ABAQUS. The calculation results show that the numerical simulation results in this paper are in good agreement with the experimental test data. Therefore, the feasibility and accuracy of the impact analysis of PMMA structures based on J-C constitutive and damage failure models in this paper are studied. Finally, based on the J-C constitutive model and damage failure model, the variation of the residual velocity of the bullet with the PMMA plate thickness is analyzed in depth, that is, the results show that the residual velocity of the bullet has a certain linear relationship with the plate thickness.
ARTICLE | doi:10.20944/preprints202306.1096.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Fall armyworm; damage; Littovir; insecticides; maize; yield; virus extracts; baculoviruses; NPV
Online: 15 June 2023 (07:52:00 CEST)
A Fall armyworm (FAW) is a major pest of maize and causes huge losses. Chemical control is the commonly used strategy FAW among farmers. Efficacy of baculovirus against FAW has been proven, however, farmers may not afford the products. The use of farmer produced baculovirus mixtures could provide an opportunity for a nature-based solution for FAW at low cost. This study evaluated the potential of virus extracted from FAW larvae treated with a commercial baculovirus (Littovir) for the management of FAW under laboratory and field conditions. In Laboratory, the virus extracted from 25, 50, 75 and 100 FAW larvae caused varied mortality on FAW instars. The highest mortality (45%) on 1st-3rd instars was caused by Littovir followed by virus extract from 100 FAW larvae (36%). Under field conditions, even though virus extracts did not offer adequate protection against the FAW damage, the maize yield was comparable to commercial insecticides treated plots. This study has shown the potential of use of virus extracts for management of FAW. This would offer the farmers a sustainable and affordable option for management of FAW as it would require the farmers to purchase the commercial baculovirus once and collect larvae from treated plots for repeat applications.
ARTICLE | doi:10.20944/preprints202306.0618.v1
Subject: Engineering, Civil Engineering Keywords: Asphalt mixes; moisture damage; indirect tensile strength; polyethylene terephthalate; international standards
Online: 8 June 2023 (09:56:04 CEST)
Water damage is one of the main causes of roads’ deterioration throughout their service life. This effect harms the adhesion and cohesion parameters of the asphalt mix, which leads to a decrease in the structural and functional characteristics of the road surface. This research focuses on studying the water susceptibility of hot mix asphalt mixtures using three different procedures: (1) UNE-EN 12697-12, (2) ASTM D4867, and (3) AASHTO T-283. The tests are carried out on reference mixtures and mixtures modified with polyethylene terephthalate (PET) particles as an additive. The results indicate that the incorporation of 6% PET allows the limits established by the UNE-EN 12697-12 standards to be exceeded, reaching 86% of the tensile strength ratio (TSR). However, for the ASTM D4867 and AASHTO T-283 standards, the results obtained concerning the water susceptibility of the bituminous mixtures were not as satisfactory because the established minimum limits were not reached (< 75%), which indicates that the procedure applied in a test can significantly modify the results of a later application.
ARTICLE | doi:10.20944/preprints202112.0043.v1
Subject: Engineering, Civil Engineering Keywords: hydro-damage; red-bed mudstone; hydrodynamic; X-ray image; seepage–diffusion
Online: 3 December 2021 (09:46:59 CET)
Nonlinear catastrophes caused by geological fluids are a fundamental issue in rock mechanics and the geoengineering hazard field. For the consideration of hydrodynamic force on red-bed mudstone softening damage, X-ray visualization test on the fissure flow in mudstone block failure under hydrodynamic force was performed in this study based on block scale and the physical phenomena of fissure seepage and nonlinear diffusion were further explored. A new method for evaluating the hydro-damage degrees of rocks using an X-ray image analysis was proposed, and the quantitative relation of diffusion coefficients of hydro-damage and seepage was established. The research results revealed that the hydrodynamic force promoted the fluid-filled fissure behavior in mudstone specimen failure. Also, the seepage and diffusion phenomena of fluid in rocks during failures were indicated using X-ray imaging. A dual mechanical behavior was presented in the nonlinear seepage and abnormal diffusion of a red mudstone geological body under hydrodynamic conditions. The damaged degree of mudstone was aggravated by the effect of hydrodynamic force, and the initial seepage–diffusion coefficient with respect to lower hydro-damage was larger than the final seepage–diffusion coefficient with respect to higher hydro-damage of rocks with a decreasing nonlinear trend.
ARTICLE | doi:10.20944/preprints202102.0122.v2
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: tomato; temperature; damage; seedling; plant; root; weight; photosynthesis; proline; electrical conductivity
Online: 20 May 2021 (09:45:18 CEST)
High temperature (HT) significantly affects the crop physiological traits and reduces the 12 productivity in plants. To increase yields as well as survival of crops under HT, developing heat13 tolerant plants is one of the main targets in crop breeding programs. The present study attempted 14 to investigate the linkage of the heat tolerance between the seedling and the reproductive growth 15 stages of tomato cultivars ’Dafnis‘ and ’Minichal’. This research was undertaken to evaluate heat 16 tolerance under two experimental designs such as screening at seedling stage and screening from 17 reproductive traits in greenhouses. Survival rate and physiological responses in seedlings of 18 tomatoes with 4-5 true leaf were estimated under HT (40 °C, RH 70%, day/night, respectively) and 19 under two control and HT greenhouse conditions (day time 28 °C and 40 °C, respectively). Heat 20 stress significantly affected physiological-chemical (photosynthesis, electrolyte conductivity, 21 proline) and vegetative parameters (plant height, shoot fresh weight, root fresh weight) in all 22 tomatoes seedlings. The finding revealed that regardless of tomato cultivars the photosynthesis, 23 chlorophyll, total proline and electrical conductivity parameters were varied in seedlings during the 24 heat stress period. The heat tolerance rate of tomatoes in the seedling stage might not be associated 25 always with reproductive parameters. HT reduced the fruit parameters likeas fruit weight (31.9%), 26 fruit length (14.1%), fruit diameter (19.1%) and fruit hardness (9.1%) in compared to NT under HT 27 in heat susceptible tomato cultivar ‘Dafnis’, while in heat tolerant cultivar ‘Minichal’ fruit length 28 (7.1%) and fruit diameter (12.1%) was decreased by the affect of HT but on the contrary fruit weight 29 (3.6%) and fruit hardness (8.3%) were increased. In conclusion, screening and selection for tomatoes 30 should be evaluated at the vegetative and reproductive stages with consideration of reproductive 31 parameters.
ARTICLE | doi:10.20944/preprints202012.0551.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Enterohemorrhagic Escherichia coli O157: H7; EspF; SMC1; CoIP-MS; DNA damage
Online: 22 December 2020 (10:33:53 CET)
The enterohemorrhagic Escherichia coli (EHEC) O157: H7 EspF is known to be a multifunctional effector that triggers several damage processes in the host cells. However, in the process of EHEC O157: H7 infection, the interactions between EspF, its N- or C-terminus, and host proteins are still unclear. In this work, we use co-immunoprecipitation combined with mass spectrometry (CoIP-MS) to screen the interactions between EspF/EspF-N/EspF-C terminus and host proteins. A total of 311 host proteins are analyzed. The N-terminus of EspF is found to interact with 192 proteins, whereas 205 proteins interact with the C-terminus. These proteins are mainly involved in RNA splicing, endoplasmic reticulum stress, and a variety of metabolic signaling pathways. Surprisingly, MS results reveal that EspF can also phosphorylate H2AX, suggesting that EspF may directly mediate DNA damage. Here, by western blot and immunofluorescence (IF), we verified that EspF can cause phosphorylation of H2AX and mediates cell multi-nuclearation and cell hypertrophy. Furthermore, we verify here for the first time that SMC1 interacts with EspF -C-terminus, and provide evidence that EspF increases p-SMC1 levels. p-SMC1 is known to influence S-phase cell cycle arrest and usually increases during periods of DNA damage. Our work revealed a novel interaction between EspF and the host protein SMC1 and lays a foundation for further research on EspF-mediated host DNA damage, apoptosis, and even colorectal carcinogenesis.
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: COVID-19; paracetamol; NSAIDs; inflammation; lung injury; oxidative damage; glutathione; antioxidant.
Online: 7 August 2020 (11:02:20 CEST)
COVID-19 pandemic represents an unprecedented sanitary threat: antiviral and host-directed medications to treat the disease are still urgently needed.A great effort has been paid to find drugs and treatments for hospitalized, severely ill patients. However, medications used for the domiciliary management of initial symptoms, notwithstanding their importance, have not been and are not presently regarded with the same attention. In analogy with other respiratory viral infections, COVID-19 patients in the early phase require specific antivirals (still lacking) and non-etiotropic drugs to lower pain, fever and control inflammation. Non-steroidal antinflammatory drugs (NSAIDs) and paracetamol (PAC) are widely used as non-etiotropic agents in these conditions and hence are both theoretically repurposable for COVID-19. However, a warning from some research reports and National Authorities raised NSAIDs safety concerns because of the supposed induction of ACE2 protein levels (the receptor used by SARS-CoV2 to enter host airways cells), the risk of bacterial superinfections and masking of disease symptoms. As a consequence, the use of NSAIDs was, and is, strongly discouraged while the alternative adoption of paracetamol is still preferred.On the basis of novel data and hypothesis on the possible role of scarce glutathione (GSH) levels in the exacerbation of COVID-19 and of the GSH depleting activity of PAC, this commentary raises the question of whether PAC may produce an oxidative imbalance which could be detrimental in COVID-19 clinical outcomes.
ARTICLE | doi:10.20944/preprints201909.0002.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: berry harvesting stages; Markov chains; Viterbi algorithm; monitoring; fruit damage indicator
Online: 1 September 2019 (08:11:54 CEST)
This article proposes a monitoring system that allows to track transitions between different stages in the berry harvesting process (berry picking, waiting for transport, transport, and arrival to the packing) solely using information from temperature and vibration sensors located in the basket. The monitoring system assumes a characterization of the process based on Hidden Markov Models and uses the Viterbi algorithm to perform inference and estimate the most likely state trajectory. The obtained state trajectory estimate is then used to compute a potential damage indicator in real-time. The proposed methodology does not require information about the weight of the basket to identify each of the different stages, which makes it effective and more efficient than other alternatives available in the industry.
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: metabolism; metabolic by products; overflow; damage; toxicity; repair; geneticist-induced stress
Online: 20 June 2019 (10:10:09 CEST)
In intermediary metabolism, enzymes are mainly for the specific provision of one small molecule from another, B from A, for its further use. But there are also decades of work relating to another evolved purpose, which is to prevent untoward effects of odd compounds of various origins, and of ordinary intermediates, whose improper concentrations may be avoided by hydrolases and other activities of metabolic correction.
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: marine mortar; multi-scale; interfacial behavior; strength; damage; on-line detection
Online: 7 May 2019 (11:38:17 CEST)
Marine mortar was the goal material and its multi-scale physical-chemical-mechanical characteristics were the principal interest in this study. The on-line multi-scale damage detection experiments art was designed to quantify the characteristics mathematically and graphically. The normal cylinder specimen with 70-day age was produced and investigated by dynamically global MSHCT scan and local detection of EDS, SEM and XRD. The experiments results indicated that the marine mortar offered the appreciable strength at the early age at least, although some saline minerals were generated during the preparation. The micro-interfacial behavior and the parental foci controlled the damage development of the marine mortar the performance of which was still the adjustable one by the composition optimization.
ARTICLE | doi:10.20944/preprints201904.0313.v1
Subject: Engineering, Energy And Fuel Technology Keywords: nanoaditives; nitrogen foamed stimulation fluids; reservoir stimulation; rheology; formation damage; SEM
Online: 28 April 2019 (10:54:56 CEST)
Impact of Nitrogen Foamed Stimulation Fluids Stabilized by Nanoadditives on Reservoir Rocks of Hydrocarbon Deposits
ARTICLE | doi:10.20944/preprints201811.0442.v1
Subject: Engineering, Mechanical Engineering Keywords: fatigue; damage; crack initiation; crack propagation; nonlinear models; crack growth retardation
Online: 19 November 2018 (10:03:14 CET)
Reliable fatigue design rules affect the proactive identification of safety parameters in aerospace industry. Numerous fatigue crack initiation and propagation models, linear and nonlinear, have been developed for designing purposes or estimation of the remaining life of aging airplanes. Depending on the adopted assumptions, the accuracy varies for different loading histories, loading types, and materials. Semi empirical models are simple but yield significant inaccuracies. Models with better theoretical basis provide better accuracy, but implementation in real conditions is problematic. In the present work, a review of author’s recent fatigue crack initiation and propagation models based on physical mechanisms is presented and improvements are proposed. Verification of the models on test results is provided and discussed.
REVIEW | doi:10.20944/preprints201809.0440.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Dormant origins; replicative stress; replication timing; DNA damage; genome instability; cancer
Online: 21 September 2018 (16:00:30 CEST)
Maintenance of the human chromosomes stability requires a tight regulation of DNA replication to duplicate once and only once the entire genome of a single cell. In mammalians cells, origin activation is controlled in space and time by a cell specific and robust program called replication timing. About 100 000 of potential origins are loaded onto the chromatin at the G1 phase but only 20-30% are selected and active during the replication of a given cell. When the replication fork is slowed down by exogenous or endogenous sources, the cell need to activate more origins to complete the replication on time. Thus, the large choice of origins that can be activated may be a key player in the protection of the genome. The aim of this review is to discuss about the role of these dormant origins as housekeepers of the human genome in response to replicative stress.