ARTICLE | doi:10.20944/preprints202103.0492.v2
Subject: Engineering, Automotive Engineering Keywords: Education Robotics; Mechanism Design; Motion Control; Barycenter Offset Robot
Online: 1 March 2022 (06:46:27 CET)
Various designs of spherical robots using barycenter offset mechanisms were previously reported. This kind of robots offers advantages such as turning in placeor moving in any direction at any time. Yet, the approaches resulting in a balanced robot, which could roll with reduced energy costs once accelerated, are scarce. We introduce anovel robot of this type. The feasibility of the approach is verified on a cylindrical robot. This paper presents an open-source, remotely controlled, robotic cylinder. The robot uses a specifically designed mechanism to displace a mass in its center, which causes the cylinder to roll forwards or backwards. The movement characteristics of the cylinder, as well as the mathematical and physical limitations of the mechanism were studied. An intuitive user interface allows the robot to be controlled through WiFi. This robot was manufactured only with readily available and inexpensive materials, which would make it a suitable platform for education, typically in the fields of physics and engineering.
ARTICLE | doi:10.20944/preprints202003.0179.v1
Subject: Engineering, Mechanical Engineering Keywords: fast tool servo; voice coil motor; flexure mechanism; resonant controller
Online: 11 March 2020 (04:04:49 CET)
In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to have a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using PID controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking.
ARTICLE | doi:10.20944/preprints201807.0442.v1
Subject: Engineering, Mechanical Engineering Keywords: electric vehicles; configuration synthesis; motor transmission; in-wheel-hub motor; six-link mechanism
Online: 24 July 2018 (05:59:20 CEST)
Nowadays, there are several electric vehicle (EV) on the market, due to the innovation of technology that promotes the new components such as battery, transmission, electric motors. This paper proposes a design approach for the configuration synthesis and simulation of the in-wheel-hub motor transmissions with the six-link mechanisms. The synthesis process shows 6 mechanisms with six members and eight joints, 15 new clutchless motor transmissions and 16 new clutched motor transmissions. A novel motor transmission in the feasibility of the synthesized configurations is selected as an example to analyze the working principle with operation modes and power flow paths. And, this design is modeled for the simulation process that generates the results of operation mode transition and energy regulation.
ARTICLE | doi:10.20944/preprints201703.0185.v1
Subject: Engineering, Mechanical Engineering Keywords: MEMS S&A device; threshold-value judging mechanism; fabrication process; tensile test; theoretical, simulationand experimentalanalysis; parametric design method
Online: 24 March 2017 (10:12:13 CET)
In order to meet the military requirements of the fuze, such as precision strike, efficient mutilates ability and low collateral damages, the microminiaturization is an inevitable trend of secure system. Based on the silicon-based MEMS S&A device designed by our term, the design principles of each module and fabrication process are introduced. The average fracture strength and Young's modulus of the silicon are 726 MPa and 175 GPa from the tensile test, respectively. From Hopkinson impact experiment, we can get the threshold-value judging mechanism being safety under the impact overload of 20526 g, and this value is much more than the standard of the drop overload 12000g; the arming value under the centrifugal overload obtained from theory, simulation and experiment is at the range of 28200 g and 32000 g, it shows that the threshold-value judging mechanism can be arming compared with the value 35951g of design principle. Therefore, the threshold-value judging mechanism can meet the design requirements of overload. Furthermore, the relationship of fracture threshold-values obtained by different theories is found out through parametric design method, as shown in Figure 14, it provides the theory evidence to the follow parametric design.
ARTICLE | doi:10.20944/preprints201904.0026.v1
Subject: Engineering, Mechanical Engineering Keywords: actuation and driving mechanism; soft robotics; soft epicyclical mechanism; Shape Memory Alloy
Online: 2 April 2019 (06:23:28 CEST)
Nowadays, the development or improvement of actuation mechanisms is a crucial topic for the achievement of dextrous manipulation using soft robots. Then, a primary target of research is the design of actuation and driving devices. Consequently, in this paper, we introduce a soft driving epicyclical mechanism that mimics human muscle behavior and fulfills motion requirements to achieve grasping gestures using a robotic finger. The prototype is experimentally assessed, and results show that our approach has enough performance for the implementation in grasping tasks. Furthermore, we introduce the basis for a new soft epicyclical mechanism merger with shape memory alloys to allow active stiffness control of the mechanism.
ARTICLE | doi:10.20944/preprints201912.0059.v2
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: hyperspectral image classiﬁcation; deep learning; channel-wise attention mechanism; spatial-wise attention mechanism
Online: 12 February 2020 (05:40:08 CET)
In recent years, researchers have paid increasing attention on hyperspectral image (HSI) classification using deep learning methods. To improve the accuracy and reduce the training samples, we propose a double-branch dual-attention mechanism network (DBDA) for HSI classification in this paper. Two branches are designed in DBDA to capture plenty of spectral and spatial features contained in HSI. Furthermore, a channel attention block and a spatial attention block are applied to these two branches respectively, which enables DBDA to refine and optimize the extracted feature maps. A series of experiments on four hyperspectral datasets show that the proposed framework has superior performance to the state-of-the-art algorithm, especially when the training samples are signally lacking.
ARTICLE | doi:10.20944/preprints201807.0307.v1
Subject: Social Sciences, Marketing Keywords: sustainable outcomes; dedication-based mechanism; constraint-based mechanism; perceived switching costs; loyalty program
Online: 17 July 2018 (10:55:47 CEST)
Given the increase in consumers’ preferences for coffee, it is becoming important to understand their decision-making processes in the coffee chain context. To deepen the understanding of sustainable outcomes in this context, this study investigates the role of dedication- and constraint-based mechanisms in forming consumers’ repurchase and positive word-of-mouth (WOM) intentions, two critical sustainable outcomes. We examined the effects of coffee quality, the quality of the physical environment, and service quality in accelerating the formation of dedication-based factors. Moreover, this study offers an in-depth understanding of the enablers of perceived switching costs. Data collected from 238 university students that frequently visit coffee chains are empirically tested against the proposed theoretical framework by using structural equation modeling. The results confirm that both dedication- and constraint-based factors substantially predict consumers’ sustainable outcomes in the coffee chain context. Brand image and perceived switching costs play an important role in enhancing consumers’ repurchase and positive WOM intentions compared with customer satisfaction. Coffee quality is significantly associated with both customer satisfaction and brand image, whereas the quality of the physical environment and service quality are only significantly associated with brand image. Habit is found to be the key enabler of perceived switching costs, while loyalty programs have no significant impact on perceived switching costs.
ARTICLE | doi:10.20944/preprints202207.0415.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: P2P botnet; Cybersecurity; detection mechanism
Online: 27 July 2022 (08:12:50 CEST)
Cybercrimes are becoming a bigger menace to both people and corporations. It poses a serious challenge to the modern digital world. According to a press release from 2019 Cisco and Cybersecurity Ventures, Cisco stopped seven trillion threats in 2018, or 20 billion threats every day, on behalf of its clients. According to Cybersecurity Ventures, the global cost of cybercrime will reach $6 trillion annually by 2021, which is significantly more than the annual damage caused by all natural disasters and more profitable than the global trade in all major illegal narcotics put together. Botnets are the most common and have a significant negative impact on any civilization among malware programmes. As a result, this study will explore various P2P botnet detection algorithms by outlining their essential characteristics, advantages and disadvantages, obstacles, and future research.
REVIEW | doi:10.20944/preprints202206.0260.v1
Subject: Life Sciences, Microbiology Keywords: canine; fecal microbiota transplantation; treatment; mechanism
Online: 20 June 2022 (05:49:24 CEST)
Fecal microbiota transplantation (FMT) is an emerging therapeutic option for a variety of diseases, which is characterized as transferring fecal microorganisms from a healthy donor into the intestinal tract of a diseased receipt. In human clinics, FMT has been used for treating diseases for decades with promising results. In recent years, veterinary specialists adapted FMT in canine patients, however, compared to humans, canine FMT is more inclined to research purposes than practical applications in most cases due to safety concerns. Therefore, in order to facilitate the application of fecal transplant therapy in dogs, in this paper, we aimed to review recent application of FMT in canine clinical treatments as well as possible mechanisms that are involved in the process of therapeutic effect of FMT.
ARTICLE | doi:10.20944/preprints202206.0231.v1
Subject: Social Sciences, Microeconomics And Decision Sciences Keywords: industrial cluster; Taobao Village; expansion mechanism
Online: 16 June 2022 (05:20:09 CEST)
China’s rural e-commerce has been developing rapidly. Taobao Villages are combination of e-commerce and rural industries. When rural e-commerce coverage evolves from Taobao village to Taobao town, the scale of industrial clusters has been expanding synchronously. This paper investigates flower and seedling industrial cluster in Xinhe Town, Yanji Town and Miaotou Town of Shuyang County, China, and conducts the econometric analysis of the expansive determinants of flower and seedling industrial cluster of Taobao Villages. An effective sample of 263 was obtained through a face-to-face survey of e-merchants of flower and seedling in the Shuyang County of Jiangsu Province. Bases on the structural equation modeling, series of test results show that the data can be used to calculate the path regression. The outcomes shows that creation of e-merchants of flower and seedling, integration of e-commerce platform, supply chain friendliness, involvement of e-commerce service providers, and governmental policy guidance are driving expansion of flower and seedling industrial cluster together, moreover, the five forces interact with each other. This implies that expansion of flower and seedling industrial cluster is a systematic process, each stakeholder needs to pay attention to the role of other forces, and five forces achieve a balanced situation in the cluster.
ARTICLE | doi:10.20944/preprints202108.0179.v1
Subject: Engineering, Mechanical Engineering Keywords: aramid fibber; ballistic test; failure mechanism
Online: 9 August 2021 (08:04:46 CEST)
The main objective of this study focuses on designing and testing body protection systems using advanced materials based on aramid fibers, for high impact speeds of up to 410...430 m/s. The investigation of the failure mechanisms identifies issues of protective materials, major challenges and technological problems for efficient development of these systems. The authors presents an investigation on the failure processes and destructive stages of a ballistic package made of succesive layers of LFT SB1plus, taking into account the particular test conditions from NIJ Standard-0101.06 Ballistic Resistance of Body Armor. The main parameter of interest was the backface signature (BFS), but also details of projectile arrest and SEM investigaton could offer arguments in using this material for individual protection.
REVIEW | doi:10.20944/preprints202007.0649.v1
Subject: Chemistry, Physical Chemistry Keywords: Glycerol polymerization; Polyglycerol; Alkaline catalyst; Mechanism
Online: 26 July 2020 (17:36:16 CEST)
Polyglycerols (PGs) are biocompatible and highly functional polyols with a wide range of applications, such as emulsifiers, stabilizers, antimicrobial agents, in many industries including cosmetics, food, plastic and biomedical. The demand increase for biobased PGs encourages researchers to develop new catalytic systems for glycerol polymerization. This review focuses on alkaline homogeneous and heterogeneous catalysts. The performances of the alkaline catalysts are compared in terms of conversion and selectivity, and their respective advantages and disadvantages are commented. While homogeneous catalysts exhibit a high catalytic activity, they cannot be recycled and reused, whereas solid catalysts can be partially recycled. The key issue for heterogenous catalytic systems, which is unsolved so far, is linked to their instability due to partial dissolution in the reaction medium. Further, this paper also reviews the proposed mechanisms of glycerol polymerization over alkaline-based catalysts and discuss the various operating conditions with an impact on the performances. More particularly, temperature and amount of catalyst proved to have a significant influence on glycerol conversion and on its polymerization extent.
ARTICLE | doi:10.20944/preprints201904.0158.v1
Subject: Materials Science, General Materials Science Keywords: LiBH4; Al; dehydrogenation mechanism; kinetic properties; reversibility
Online: 15 April 2019 (10:53:00 CEST)
A detailed analysis of the dehydrogenation mechanism and reversibility of LiBH4 doped by active Al* derived from AlH3 was performed by thermogravimetry (TG), differential scanning calorimetry (DSC), mass spectral analysis (MS), powder X-ray diffraction (XRD), scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The results show that the dehydrogenation of LiBH4/Al* is a five-step reaction: (1) LiBH4 + Al → LiH + AlB2 + “Li-Al-B-H” + B2H6 + H2; (2) the decomposition of "Li-Al-B-H" compounds liberating H2; (3) 2LiBH4 + Al → 2LiH + AlB2 + 3H2; (4) LiBH4 → LiH + B + 3/2H2; (5) LiH + Al → LiAl + 1/2H2. And the reversibility of LiBH4/Al* composite is based on equation as follows: LiH + LiAl + AlB2 + 7/2H2 ↔ 2LiBH4 + 2Al. The extent of dehydrogenation reaction between LiBH4 and Al* greatly depends on the precipitation and growth of reaction products (LiH, AlB2 and LiAl, etc.) on the surface of Al*. A passivation shell of Al* formed by these products is the kinetic barrier to the dehydrogenation of LiBH4/Al* composite.
ARTICLE | doi:10.20944/preprints201807.0598.v1
Subject: Keywords: biofilm, biofilm formation organism, Mechanism of Biofilm
Online: 30 July 2018 (15:59:05 CEST)
Biofilms are usually defined as surface-associated microbial communities, surrounded by an extracellular polymeric substance matrix. There are three major steps that are observed in biofilm formation: initial attachment events, microcolony formation and construction of mushroom-like structure with secretion of extracelluar polymeric substances. These substances can be considered a mechanism to protect the bacterial community from external insults.Biofilms, significantly increase the ability of the pathogen to evade both host defenses and antibiotics and they are being implicated in the pathogenesis and also clinical manifestation of several infections. They cause a variety of persistent infections, such as native valve endocarditis, osteomyelitis, dental caries, middle ear infections, ocular implant infections, urinary tract infections and cystic fibrosis. Established biofilms can tolerate antimicrobial agents at concentrations of 10–1000-times that needed to kill genetically equivalent planktonic bacteria, and are also resistant to phagocytosis, making biofilms extremely difficult to eradicate from living hosts. Consequently, biofilm-related infections that appear to respond to a therapeutic course of antibiotics may relapse weeks or even months later, making surgical removal and replacement of the infected tissue or medical device a frequent and unfortunate necessity.Several pathogens associated with chronic infections, including Pseudomonas aeruginosa in cystic fibrosis pneumonia, Haemophilus influenzae and Streptococcus pneumoniae in chronic otitis media and Enteropathogenic Escherichia coli in recurrent urinary tract infections, are linked to biofilm formation.
ARTICLE | doi:10.20944/preprints201705.0155.v1
Subject: Materials Science, Polymers & Plastics Keywords: single fiber; cutting; fracture morphology; failure mechanism
Online: 22 May 2017 (05:29:48 CEST)
The present study investigates the failure mechanisms of industrial fiber materials, using a custom designed fiber cutting performance test bench. The fracture morphologies of single PA6 fibers are examined by scanning electron microscopy. The analysis reveals that fiber cutting can be distinguished according to four distinct stages of fiber failure represented by shearing, cutting, brittle fracture, and tensile failure, which are the result of different mechanisms active during the processes of crack initiation, extension and fracture. The results of fractographic analysis are further verified by an analysis of the blade assembly speed with respect to time over the entire fracture failure process based on high-speed camera data. The results of fractographic analysis and blade assembly speed are fully consistent.
REVIEW | doi:10.20944/preprints202204.0093.v1
Subject: Life Sciences, Immunology Keywords: Electrophile signaling; drug mechanism; immunology; antioxidant response; apoptosis
Online: 11 April 2022 (10:39:31 CEST)
Here we draw insights from the latest serendipitous findings made on the opposing roles of a validated drug-target protein Keap1. We weigh up how natural reactive electrophiles and electrophilic small-molecule drugs in clinical use directly impinge on seemingly conflicting, yet both Keap1-electrophile-modification-dependent, cell-survival- vs. cell-death-promoting behaviors. In the process, we convey how understanding reactive chemical-signal regulation at a single-protein-specific level is an enabling necessity in deconstructing otherwise intricate reactive-small-molecule-responsive cellular pathways. We hope this opinion piece further spurs the broader interests of basic and pharmaceutical research communities toward better understanding of molecular mechanisms underpinning reactive small-molecule-regulated signaling subsystems.
ARTICLE | doi:10.20944/preprints201908.0128.v2
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: Nash equilibria; Mechanism design; Artificial inference; Global learning
Online: 31 January 2022 (11:19:04 CET)
This paper presents an extension of the results obtained in previous work concerning the application of global optimization techniques to the design of finite strategic games with mixed strategies. In that publication the Fuzzy ASA global optimization method was applied to many examples of synthesis of strategic games with one previously specified Nash equilibrium, evidencing its ability in finding payoff functions whose respective games present those equilibria, possibly among others. That is to say, it was shown it is possible to establish in advance a Nash equilibrium for a generic finite state strategic game and to compute payoff functions that will make it feasible to reach the chosen equilibrium, allowing players to converge to the desired profile, con- sidering that it is an equilibrium of the game as well. Going beyond this state of affairs, the present article shows that it is possible to ”impose” multiple Nash equilibria to finite strategic games by following the same reasoning as before, but with a fundamental change: using the same fundamental theorem of Richard McKelvey, modifying the originally prescribed objective function and globally minimizing it. The proposed method, in principle, is able to find payoff functions that result in games featuring an arbitrary number of Nash equilibria, paving the way to a substantial number of potential applications.
ARTICLE | doi:10.20944/preprints202105.0562.v1
Subject: Materials Science, Biomaterials Keywords: MgAl2O4, Single atomic Nin+, RWGS, Stability, Reaction mechanism
Online: 24 May 2021 (10:50:17 CEST)
Reverse water gas shift reaction (RWGS) is an important process which plays a vital role in many CO2 utilization related reactions. Noble metals are the most active catalysts in RWGS, but the high price and low reserve strangled their applications. In the present work, we reported a non-transition-metal MgAl2O4 catalyst which showed outstanding activity and stability at high temperatures in the RWGS reaction and improved performance after doping of single atomic Nin+. The catalyst can obtain 46% of CO2 conversion in durability test of 75 h at 800 °C under high weight hourly space velocities (225 000 ml g-1 h-1). The adsorption sites, possible reaction route, and effects of Nin+ single atoms on the (111) surface of MgAl2O4 for RWGS were investigated by in situ DRIFTS and DFT calculations. The results indicated that the rate determining reaction step of RWGS on MgAl2O4 and Ni (SA)/MgAl2O4 were both the reaction of OH* + H* → H2O* + *, but the energy barrier was significantly reduced after introducing single atomic Nin+. Nin+ atoms can increase the hydroxyl coverage on the surface of catalyst and Al3+ sites near the Nin+ ion are considered as the predominant active sites for RWGS reactions.
REVIEW | doi:10.20944/preprints202103.0031.v1
Subject: Materials Science, Biomaterials Keywords: Dermal wound; Nanocuetical; Wound biochemistry; Wound healing mechanism
Online: 1 March 2021 (14:21:46 CET)
Dermal wound healing describes the progressive repair and recalcitrant mechanism of damaged skin and eventually reformatting and reshaping the skin. Many probiotics, nutraceuticals, metal nanoparticles have been associated with improved healing process of intra and inter tissue wounds. Despite the vast nature on material based wound healing mediators, the exact mechanism on material-cellular interaction is still point of repent issue particularly in diabetics and pathological condition. The use of bioengineered alternative agents will likely only continue to dominate the outpatient and perioperative management of chronic, recalcitrant wounds as new additional products continue to cut costs and improve wound healing process. This review article provides an update of the various remedies with confirmed wound healing activities by a diverse group of agents from previous experiments conducted by various researchers
ARTICLE | doi:10.20944/preprints202012.0447.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Injury mechanism; Muscle strengthening; Neuromotor; Neurocognitive; Injury Prevention
Online: 18 December 2020 (08:34:06 CET)
Anterior Cruciate Ligament (ACL) tear is currently a main issue in all of sports communities. Although the number of ACL injuries in football remains low, it’s consequences on both professional and personal lives remain a major concern of rehabilitation. If practitioners often require more time to bring athletes in the best condition, the fact remains that this concept of time before return to sport is nowadays considered as obsolete. Indeed, the better understanding of the mechanisms of lesion and the strains placed on the graft after reconstruction, allow us to establish a personalized program based on clinical criteria and the patient's objectives. The current scientific literature allows us today to optimize the return to play and performance by the use of neuromotor and neurocognitive approaches, muscle strengthening methods and a preventive program necessary to cover the previous level of the players while taking into account physiological and psychological changes due to ACL reconstruction. Indeed, it is important to have a systemic approach centered on the patient, the sports movement, as close as possible to the field in order to find an optimal function of the knee in interaction with its environment.If there is a risk of reinjury of the ACL, it appears important to be able to identify the risk factors so that the player can return to play in optimal conditions.
ARTICLE | doi:10.20944/preprints201811.0629.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: bufadienolides-like chemicals; molecular mechanism; anti-cancer; bioinformatics
Online: 30 November 2018 (10:14:58 CET)
Bufadienolides-like chemicals, which mostly composed the active ingredient of Chansu, had been widely discovered to possess anti-inflammatory, tumor-suppressing and antipain activity, but the mechanisms of action were not clearly illuminated. In this research, in order to explore the potential mechanism of bufadienolides-like chemicals on breast cancer, a serious of bioinformatics analysis, included (1) differentially expressed genes identification combined with gene set variation analysis, (2) tissue specific co-expression network construction, (3) differentially regulated sub-networks detection with disease phenome, (4) hub gene selection and it’s relation to survival probability, and (5) similar small molecule detection were performed with gene expression profiles of bufadienolides-like chemicals. Results indicated bufadienolides-like chemicals had the most same target with valproic, estradiol and etc, could disturbed the pathways in RNA splicing, apoptotic process, cell migration, extracellular matrix organization, adherens junction organization, synaptic transmission, Wnt signaling, AK-STAT signaling, BMP signaling pathway and unfolded protein response, and had the potential ability to be used as anticancer, hormones and vasoprotectives agents.
ARTICLE | doi:10.20944/preprints201801.0271.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: breast cancer; ginkgolic acid C13:0; mechanism; CYP1B1
Online: 29 January 2018 (09:57:10 CET)
Ginkgolic acids (GA) have been reported to exhibit anticancer properties, however, the mechanisms remain unclear. This study aims to investigate the mechanisms of GA C13:0 that was isolated from Ginkgo biloba exocarp (GBE) for anti-proliferation, pro-apoptosis and anti-migration effects in human MCF-7 and mouse 4T-1 breast cancer cells. The cytotoxic effect, apoptosis induction and migration inhibition were measured using MTT, TUNEL and Wound healing assays. The expression of mRNA and protein were determined using qPCR and Western blot. Our results showed that no cytotoxicity was found at concentrations of C13:0 below 100µM. The effects of GA C13:0 was further demonstrated by up-regulation of the Bax/Bcl-2 apoptosis pathway and the expression of Apaf-1 protein in the mitochondria. In addition, GA C13:0 also suppressed cell migration and epithelial to mesenchymal transition (EMT) with the increase of E-cadherin expression accompanied by the decrease of Snail, MMP-2, MMP-9 and Vimentin expression. Moreover, GA C13:0 induced cytochrome P450 (CYP) 1B1 expression in aryl hydrocarbon receptor (AhR) pathway. Notably, the up-regulation of CYP1B1 also might play a pivotal regulatory role in mitochondrial and EMT pathways in MCF-7 and 4T-1 cells. Our results may have implications for the development of anticancer agents containing GA as functional additives.
ARTICLE | doi:10.20944/preprints201711.0001.v1
Subject: Materials Science, Metallurgy Keywords: corrosion behavior; FG20; electrochemical measurements; EPMA; corrosion mechanism
Online: 1 November 2017 (04:15:39 CET)
In some sour reservoirs and tertiary oil recovery blocks, SO42- in solution can cause the corrosion and corrosion fatigue of the sucker rods. In this paper, the corrosion behaviors of super-strength sucker rod FG20 (16Mn2SiCrMoVTiA) steel in the well fluid are investigated by electrochemical measurements, and electron probe micro-analyzer (EPMA) analysis. The results show that FG20 steel has a favorable corrosion resistance in neural solutions. When the hydrogen ion content increases, the hydrolysis of SO42- greatly accelerates the corrosion of FG20 steel. The energy dispersive X-ray(EDX)results demonstrate that the corrosion process of FG20 steel in neural well liquid is an oxygen concentration process, and the protective FeCO3 and Fe2O3 on the surface of the samples can prevent further corrosion. With the increase of the acidity in the well liquid, the corrosion process converts into a sulphide concentration process, and the sloppy FeS and mackinawite film cannot provide effective protection for the specimens, resulting in the increase of corrosion rate.
ARTICLE | doi:10.20944/preprints202011.0283.v1
Subject: Biology, Anatomy & Morphology Keywords: Salvia sclarea; chlorophyll fluorescence imaging; non-photochemical quenching; tolerance mechanism; photoprotective mechanism; photosynthesis; reactive oxygen species; toxicity; adaptive response, photochemical efficiency
Online: 9 November 2020 (16:06:01 CET)
Five-day exposure of clary sage (Salvia sclarea) to 100 μM cadmium (Cd) in hydroponics was sufficient to increase Cd concentrations significantly in roots and aboveground parts and affect negatively whole plant levels of calcium (Ca) and magnesium (Mg), since Cd competes for Ca channels, while reduced Mg concentrations are associated with increased Cd tolerance. Total zinc (Zn), copper (Cu), and iron (Fe) uptake increased but their translocation to the aboveground parts decreased possible due to translocation barriers. Despite the substantial levels of Cd in leaves, without any observed defects on chloroplast ultrastructure, an enhanced photosystem II (PSII) efficiency was observed, with a higher fraction of absorbed light energy to be directed to photochemistry (ΦPSΙΙ). The concomitant increase in the photoprotective mechanism of non-photochemical quenching of photosynthesis (NPQ) resulted in an important decrease in the dissipated non-regulated energy (ΦNO), modifying the homeostasis of reactive oxygen species (ROS), through a decreased singlet oxygen (1O2) formation. Thus, when clary sage was exposed to Cd for a short period, tolerance mechanisms were triggered, with PSII photochemistry to be regulated by NPQ in such a way that PSII efficiency to be enhanced. However, exposure to a combination of Cd and high light or for longer duration (8 days) to Cd alone, resulted in an inhibition of PSII functionality pointing out towards Cd toxicity. Thus, the rapid activation of PSII functionality at short time exposures and the inhibition at longer duration suggests a hormetic response and describes these effects in terms of “adaptive response” and “toxicity”, respectively.
ARTICLE | doi:10.20944/preprints202202.0159.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: hybrid degradation; generative adversarial network; attention mechanism; disentangled representation
Online: 11 February 2022 (08:42:43 CET)
In this paper, we propose an unsupervised blind restoration model for images in hybrid degradation scenes. The proposed model encodes the content information and degradation information of images and then uses the attention module to disentangle the two kinds of information. It can improve the ability of disentangled presentation learning for a generative adversarial network (GAN) to restore the images in hybrid degradation scenes, enhance the detailed features of restored image and remove the artifact combining the adversarial loss, cycle-consistency loss, and perception loss. The experimental results on the DIV2K dataset and medical images show that the proposed method outperforms existing unsupervised image restoration algorithms in terms of peak signal-to-noise ratio (PSNR), structural similarity (SSIM), and subjective visual evaluation.
REVIEW | doi:10.20944/preprints202201.0440.v1
Subject: Life Sciences, Other Keywords: electrophiles; signaling; profiling; drug mechanism; drug discovery; T-REX
Online: 28 January 2022 (14:57:08 CET)
Our bodies produce a host of electrophilic species that can label specific endogenous proteins in cells. The signaling roles of these molecules are underactive debate. However, in our opinion it is becoming increasingly likely that electrophiles can rewire cellular signaling processes at endogenous levels. Attention is turning more to understanding how nuanced electrophile signaling in cells is. In this perspective, we describe recent work from our laboratory that has started to inform on different levels of context-specific regulation of proteins by electrophiles. We discuss the relevance of these data to the field, and to the broader application of electrophile signaling to precision medicine development, beyond the traditional views of their pleiotropic cytotoxic roles.
ARTICLE | doi:10.20944/preprints202108.0012.v1
Subject: Engineering, Automotive Engineering Keywords: Contract Theory; Incentive Mechanism; Cooperative NOMA; SWIPT; Full Duplex
Online: 2 August 2021 (10:03:27 CEST)
Cooperative Non-Orthogonal Multiple Access (NOMA) with Simultaneous Wireless Information and Power Transfer (SWIPT) communication can effectively improve the spectrum efficiency and energy efficiency of the wireless networks with extend coverage. An important design issue is to incentivize a relaying center user to participate in the cooperative process and achieve a win-win situation to both the BS and the center user. Some private information of the center users are hidden from the BS in the networks. We apply a contract theory-based incentive mechanism under such asymmetric information scenario to incentives center user to join the cooperative communication to maximize the BS profit utility and to guarantee the center user’s expect payoff. A match theory-based Gale-Shapley algorithm is proposed to obtain the optimal strategy with low computation complexity. Simulation results indicated the network performance of our proposed cooperative transmission is much better than the conventional NOMA transmission and the benefit utility of the BS with the stable match strategy is nearly close to the complete channel state information multi-users scenario while the center users get the satisfied expect payoffs.
COMMUNICATION | doi:10.20944/preprints202107.0500.v1
Subject: Engineering, Automotive Engineering Keywords: Clinching; binding mechanism; process chain; torsion test; electrical test
Online: 21 July 2021 (15:33:17 CEST)
The multi-material design and the adaptability of a modern process chain require joining connections with specifically adjustable mechanical, thermal, chemical or electrical properties, whereby previous considerations have focused primarily on the mechanical properties. With clinching, the multitude of possible combinations of requirements, materials and component or joint geometry makes it impossible to determine these joint properties empirically. As a result of the established and empirically based procedure, no model exists to date that considers all questions of joinability, i.e. the materials (suitability for joining), the design (joining safety) and the production (joining possibility) and allows a calculation of the achievable properties. It is therefore necessary to describe the physical properties of the joint as a function of the three bonding mechanisms force closure, form closure and material closure in relation to the application. This approach enables the illustration of the relationships along the causal chain "joint requirement - binding mechanism - joining parameters". In this way the adaptability of the mechanical joining technology can be improved. A geometric comparison is made using metallographic cross sections, of clinched joints of the combination of aluminum and steel. The torsional testing of the rotationally symmetric clinching points for detection of the mechanical stress state are qualified as examination method and technological test. By measuring the electrical resistance in the base material, in the clinch joint and during the production cycle (after clinching, before precipitation hardening and after precipitation hardening), this change in the stress state can also be detected.
ARTICLE | doi:10.20944/preprints202107.0201.v1
Subject: Social Sciences, Accounting Keywords: Internet use; social capital; income gap between farmers; mechanism
Online: 8 July 2021 (13:26:17 CEST)
Based on 2010, 2013 and 2015 CGSS data, the impact of Internet use and social capital on the income gap among farmers in the past five years is assessed at three time points using the OLS method and a quantile regression method. The study finds that (1) the income gap among farmers increases continuously in the five-year period, while Internet use plays a positive impact on farmers’ income growth in all five quartiles; the coefficient differences are all significantly negative, indicating that Internet use plays a positive role in alleviating the income gap between high-income and low-income farmer subgroups, and (2) social capital plays a positive role in moderating the income gap among farmers and that Internet use by farmers expands the boundary of social capital, which in turn increases the income level of and alleviates the income gap among farmers.
CONCEPT PAPER | doi:10.20944/preprints202106.0578.v1
Subject: Biology, Animal Sciences & Zoology Keywords: homology; developmental mechanism; evidential integration; eumetazoan body plan; phylogenetics
Online: 23 June 2021 (11:45:06 CEST)
Reconstructing ancestral species is a challenging endeavour: fossils are often scarce or enigmatic, and inferring ancestral characters based on novel molecular approaches (e.g. comparative genomics or developmental genetics) has long been controversial. A key philosophical challenge pertinent at present is the lack of a theoretical framework capable of evaluating inferences of homology made through integration of multiple kinds of evidence (e.g. molecular, developmental, or morphological). Here, I present just such a framework. I start with a brief history and critical assessment of attempts at inferring morphological homology through developmental genetics. I then bring attention to a recent model of homology, namely Character Identity Mechanisms (DiFrisco, Love, & Wagner, 2020), intended partly to elucidate the relationships between morphological characters, developmental genetics, and homology. I utilise and build on this model to construct the evaluative framework mentioned above, which judges the epistemic value of evidence of each kind in each particular case based on three proposed criteria: effectiveness, admissibility, and informativity, as well as providing a generalised guideline on how it can be scientifically operationalised. I then point out the evolution of the eumetazoan body plan as a case in point where the application of this framework can yield satisfactory results, both empirically and conceptually. I will conclude with a discussion on some potential implications for more general philosophy of biology and philosophy of science, especially surrounding evidential integration, models and explanation, and reductionism.
Subject: Materials Science, Biomaterials Keywords: Zinc nanoparticles; Plant extract; Green Synthesis; Characterization; Mechanism; Applications
Online: 28 May 2021 (09:58:44 CEST)
Background:Boom in nanotechnology in current era has sketched unforeseen transformations in number of fields, such as medicine, health care, food, space, agriculture, etc. The synthesis of nanoparticles with different chemical compositions, sizes, shapes and controlled disparities is an important area of research in this field. Over the last decade, the biosynthesis of metal nanoparticles has received considerable attention due to their unusual and fascinating properties, with various applications, over their bulk counterparts.Hypothesis: The nanoparticle can have huge application in the field of food, pharmaceutical, and cosmetic industries and thus become a major area of research. Green synthesis of zinc oxide nanoparticles (ZnO NPs) using plant extracts offers an eco-friendly and promising substitute to the conventional methods of chemical synthesis. Conclusion: In the arena of nanoparticle phytosynthesis, novel materials have been produced that are eco-friendly, cost-effective and stable. In the current situation, nanotechnology inspires progress in all spheres of life, and therefore the phytosynthetic path of nanoparticle synthesis has emerged as a safe and best alternative to conventional methods. This review summarizes the recent work in the field of zinc nanoparticle phytosynthesis and critically discusses the mechanism proposed behind it.
REVIEW | doi:10.20944/preprints202104.0069.v1
Subject: Biology, Anatomy & Morphology Keywords: willow bark; chemical characterization; mechanism; broiler diet; heat stress
Online: 2 April 2021 (14:09:52 CEST)
Over the last decade, there has been a growing interest in the use of a wide range of phytoadditives to counteract the harmful effects of heat stress in poultry. Willow (Salix spp.) is a tree with a long history. Among various forms, willow bark is an important natural source of salicin, β-O-glucoside of saligenin, but also of polyphenols (flavonoids and condensed tannins) with antioxidant, antimicrobial and anti-inflammatory activity. In light of this, the current review presents some literature data aiming to: (1) describe the relationship between heat stress and oxidative stress in broilers, (2) present or summarize literature data on the chemical composition of Salix species, (3) summarize the mechanisms of action of willow bark in heat-stressed broilers, (4) present different biological effects of the extract of Salix species in different experimental models.
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: Amharic script; Attention mechanism; OCR; Encoder-decoder; Text-image
Online: 15 October 2020 (13:42:28 CEST)
In the present, the growth of digitization and worldwide communications make OCR systems of exotic languages a very important task. In this paper, we attempt to develop an OCR system for one of these exotic languages with a unique script, Amharic. Motivated by the recent success of the Attention mechanism in Neural Machine Translation (NMT), we extend the attention mechanism for Amharic text-image recognition. The proposed model consists of CNNs and attention embedded recurrent encoder-decoder networks that are integrated following the configuration of the seq2seq framework. The attention network parameters are trained in an end-to-end fashion and the context vector is injected, with the previously predicted output, at each time steps of decoding. Unlike the existing OCR model that minimizes the CTC objective function, the new model minimizes the categorical cross-entropy loss. The performance of the proposed attention-based model is evaluated against the test dataset from the ADOCR database which consists of both printed and synthetically generated Amharic text-line images and achieved promising results with a CER of 1.54% and 1.17% respectively.
ARTICLE | doi:10.20944/preprints202009.0416.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: adversarial learning; deep cross-modal hashing; self-attention mechanism
Online: 18 September 2020 (04:16:58 CEST)
Recently deep cross-modal hashing networks have received increasing interests due to its superior query efficiency and low storage cost. However, most of existing methods concentrate less on hash representations learning part, which means the semantic information of data cannot be fully used. Furthermore, they may neglect the high-ranking relevance and consistency of hash codes. To solve these problems, we propose a Self-Attention and Adversary Guided Hashing Network (SAAGHN). Specifically, it employs self-attention mechanism in hash representations learning part to extract rich semantic relevance information. Meanwhile, in order to keep invariability of hash codes, adversarial learning is adopted in the hash codes learning part. In addition, to generate higher-ranking hash codes and avoid local minima early, a new batch semi-hard cosine triplet loss and a cosine quantization loss are proposed. Extensive experiments on two benchmark datasets have shown that SAAGHN outperforms other baselines and achieves the state-of-the-art performance.
ARTICLE | doi:10.20944/preprints202005.0439.v3
Subject: Life Sciences, Biochemistry Keywords: curcumin; COVID-19; nucleocapsid phosphoprotein; membrane glycoprotein; antiviral mechanism
Online: 7 June 2020 (17:21:49 CEST)
Corona virus disease 2019 (COVID-19) is caused by a Severe Acute Respiratory Syndrome-Coronavirus 2 (SARS-CoV-2), which is a positive strand RNA virus. The SARS-CoV-2 genome and its association to SAR-CoV-1 vary from ca. 66% to 96% depending on the type of betacoronavirdeae family members. With several drugs, viz. chloroquine, hydroxychloroquine, ivermectin, artemisinin, remdesivir, azithromycin considered for clinical trials, there has been an inherent need to find distinctive antiviral mechanisms of these drugs. Curcumin, a natural bioactive molecule has been shown to have a therapeutic potential for various diseases, but its effect on COVID-19 has not been explored. In this study, we show the binding potential of curcumin targeted to a variety of SARS-CoV-2 proteins, viz. spike glycoproteins (PDB ID: 6VYB), nucleocapsid phosphoprotein (PDB ID: 6VYO), membrane glycoprotein (PDB ID: 6M17) along with nsp10 (PDB ID: 6W4H) and RNA dependent RNA polymerase (PDB ID: 6M71) structures. Our results indicate that curcumin has high binding affinity towards nucleocapsid and nsp 10 proteins with potential antiviral activity.
COMMUNICATION | doi:10.20944/preprints201910.0068.v1
Online: 7 October 2019 (12:15:26 CEST)
I have recently reiterated that the cross-bridge is a calcium ATPase that is inhibited by magnesium and this arises because in normal hearts Myosin binding Protein-C prevents the use of MgATP as rate limiting substrate ensuring that Ca2+ replaces Mg2+ in the excitation pathway. Here I revisit the studies on [Ca2+] dependency of ATPase and tension under diastolic stretch with a different conclusion on Hill coefficients. This reveals the underlying mechanisms of the Frank-Starling Law and Hypertrophic myopathy are not the same, the former being kinase controlled.
ARTICLE | doi:10.20944/preprints201909.0341.v1
Subject: Life Sciences, Biochemistry Keywords: Covalent labeling; stereoselectivity; electrophile signaling; affinity; mechanism; kinetic control
Online: 30 September 2019 (07:53:42 CEST)
Significance: Electrophile signaling is coming into focus as a bona fide cell signaling mechanism. The electrophilic regulation occurs typically through a sensing event (i.e., labeling of a protein) and a signaling event (the labeling event having an effect of the proteins activity, association, etc.). Recent advances: Herein, we focus on the first step of this process, electrophile sensing. Electrophile sensing is typically a deceptively simple reaction between the thiol of a protein-cysteine, of which there are around 200,000 in the human proteome, and a Michael acceptor, of which there are numerous flavors, including enals and enones. Recent data overall paint a picture that despite being a simple chemical reaction, electrophile sensing is a discerning process, showing labeling preferences that are often not in line with reactivity of the electrophile. Critical issues: With a view to trying to decide what brings about highly electrophile-reactive protein-cysteines, and how reactive these sensors may be, we discuss aspects of the thermodynamics and kinetics of covalent/non-covalent binding. Data made available by several laboratories indicate that it is likely that specific proteins exhibit highly stereo- and chemoselective electrophile sensing, which we take as good evidence for recognition between the electrophile and the protein prior to forming a covalent bond. Future directions: We propose experiments that could help us gain a better and more quantitative understanding of the mechanisms through which sensing comes about. We further extoll the importance of performing more detailed experiments on labeling and trying to standardize the way we assess protein-specific electrophile sensing.We propose experiments that could help us gain a better and more quantitative understanding of the mechanisms through which sensing comes about. We further extoll the importance of performing more detailed experiments on labeling and trying to standardize the way we assess protein-specific electrophile sensing.
REVIEW | doi:10.20944/preprints201908.0279.v1
Subject: Materials Science, Nanotechnology Keywords: Acetaldehyde; Chemiresistive gas sensor, Nanostructured metal oxide, Sensing mechanism.
Online: 27 August 2019 (09:59:08 CEST)
Volatile organic compounds (VOCs) are among the most abundant air pollutants. Their high concentrations can adversely affect the human body and therefore, early detection of VOCs is of outmost importance. Among the different VOCs, in this review paper, we have focused our attention on the monitoring of acetaldehyde by chemiresistive gas sensors using nanostructured semiconducting metal oxides. These sensors not only can provide a high sensing signal for detection of acetaldehyde, but also high thermal and mechanical stability and low price. This review paper is divided into three major sections. First, we will introduce acetaldehyde as the target gas and the importance of its detection. Then, the fundamentals of chemiresistive gas sensors will be briefly presented and, in the last section, a survey of literature on acetaldehyde gas sensors will be discussed. Acetaldehyde sensors working mechanism, their structures and configurations are reviewed. Finally, the future development outlook and potential applications are discussed, giving a complete panoramic view for researcher working and interested in acetaldehyde detection for different purposes in many fundamentals and applicative fields.
ARTICLE | doi:10.20944/preprints201908.0259.v1
Subject: Physical Sciences, Particle & Field Physics Keywords: Higgs mechanism; Yukawa coupling; fine structure constant; leptons; quarks
Online: 25 August 2019 (17:06:35 CEST)
The problem of Yukawa couplings being arbitrary parameters in the Standard Model Higgs mechanism is a long standing one due to their formulaic dependence on the Higgs Vacuum Expectation Value. We will attempt to solve this problem and provide a strong argument that the Yukawa couplings of charged leptons and down type quarks are not arbitrary parameters in the SM. A new methodology for predicting the Yukawa couplings will be presented by using Compton wavelengths, the Rydberg Constant and g-factors of charged leptons instead of relying on the Higgs VEV. We will then proceed to rewrite this new method in terms of an empirical formula that depends on the running of the fine-structure constant on the Q scale, charge and lepton quantum numbers and g-factors to predict the values of the Yukawa couplings for all three generations of charged leptons and d-type quarks. We will also touch on the subject of neutrinos both as Majorana and Dirac fermions respectively and make a prediction for the lightest possible Majorana neutrino and the differences between Dirac neutrinos and anti-neutrinos. We conclude that the Yukawa couplings are not arbitrary parameters in the SM and that this new formula provides very accurate results.
Subject: Physical Sciences, Other Keywords: polyethylene; crystallinity; breakdown strength; conduction mechanism; SCLC; Field strength.
Online: 17 July 2019 (10:20:59 CEST)
In order to study the crystallinity of different density polyethylenes, the experimental study on the transformation of the conductance mechanism under high electric field was carried out. The X-ray Diffraction(XRD), Different Scanning Calorimeter(DSC), Direct Current(DC) breakdown of Low-density polyethylene(LDPE), Linear low density polyethylene(LLDPE), Medium density polyethylene(MDPE) and High-density polyethylene(HDPE) and the electric field of 5-200kV/mm were tested. Conductivity characteristics experiments, in addition, using the mathematical formula of a variety of conductance mechanisms, the electric field-current density curves of the four kinds of polyethylene were fitted to analyze the conductance transition of the above four kinds of polyethylene in non-ohmic regions under different high field strengths. mechanism. The experimental results show that as the density of polyethylene increases, the crystallinity increases continuously, and the continuous increase of crystallinity causes the electric conduction flow under the same field strength to decrease significantly. The field strength corresponding to the two turning points in the conductance characteristic curve increases simultaneously. Large, the breakdown field strength increases; through analysis, it is found that in the high field, as the electric field increases, the conductance mechanism develops from the ohmic conductance of the low field strength region to the bulk effect of the high field strength region (Poole-Frenkel). Then the electrode effect to the high field strength (Schottky), and the threshold field strength of this conductance mechanism transition increases with the increase of crystallinity.
ARTICLE | doi:10.20944/preprints201905.0167.v1
Subject: Physical Sciences, Other Keywords: Morus alba L.; Salinity; Alkalinity; Proteomics; Photosynthesis; Photoprotective mechanism
Online: 14 May 2019 (10:19:19 CEST)
Photosynthetic function, photoprotection, and the response of related proteomics of mulberry (Morus alba L.) seedling leaves under NaCl and NaHCO3 stress with the same Na+ concentration (100 mmol•L-1) were studied by using photosynthetic gas exchange and chlorophyll fluorescence techniques combined with TMT proteomics. The results showed that NaCl stress had no significant effect on photosystem II (PSII) activity in mulberry seedling leaves, and the expressions of the related proteins, OEE3-1 and PPD4, of the PSII oxygen-evolving complex (OEC) and the antenna proteins, CP24 10A, CP26, and CP29, of LHCII in the leaves also increased to varying degrees. The photosystem I (PSI) activity in the leaves of mulberry seedling also increased, and the expressions of some proteins, PsaF, PsaG, PsaH, PsaL, PsaN, and Ycf4, in PSI increased significantly under NaCl stress. Under NaHCO3 stress, the activity of PSII and PSI and the expression of their protein complexes and the electron transfer-related proteins significantly decreased. NaCl stress had little effect on RuBP regeneration during dark reaction in the leaves and the expressions of glucose synthesis related proteins and net photosynthetic rate (Pn) did not decrease significantly. The leaves could adapt to NaCl stress by reducing stomatal conductance (Gs) to increase water use efficiency (WUE). Under NaHCO3 stress, the expression of dark reaction-related proteins was mostly down-regulated, and Gs was significantly reduced, which indicated that non-stomatal factors were important reasons for the significant inhibition of carbon assimilation. In the photoprotective mechanism under NaCl stress, the expression of cyclic electron flow (CEF) related proteins, ndhH, ndhI, ndhK, and ndhM, involved in NAD(P)H dehydrogenase (NDH) and the key enzyme of the xanthophyll cycle, violaxanthin de-epoxidase (VDE) were up-regulated. In addition, the ratio of xanthophyll cycle components (A+Z)/(V+A+Z) was increased. The expressions of proteins FTR and Fd-NiR, which are related to Fd-dependent ROS metabolism and nitrogen metabolism, were also significant up-regulated under NaCl stress, which can effectively reduce the electronic pressure on Fd. Under NaHCO3 stress, the expressions of CEF-related proteins, VDE, ZE, FTR, Fd-NiR, Fd-GOGAT, SGAT, and GGAT, were significant down-regulated, and the photoprotective mechanism, like the xanthophyll cycle, CEF, and photorespiration, might be damaged, resulting in the inhibition of PSII activity and carbon assimilation in leaves of mulberry seedling under NaHCO3 stress.
ARTICLE | doi:10.20944/preprints202206.0187.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Membrane fouling; Hermia model; Fouling model; Pore blocking; Blocking mechanism
Online: 13 June 2022 (12:54:53 CEST)
One of the most broadly used models for membrane fouling is the Hermia model, which separates this phenomenon into four blocking mechanisms, each with an associated parameter n. These mechanisms are complete blocking (n=2), intermediate blocking (n=1), standard blocking (n=3/2) and cake formation (n=0). The original model, which was obtained through experimental data, is given by an Ordinary Differential Equation (ODE) dependent on n. At the time, this ODE was only solved for these four values of n, which limits the effectiveness of the model when adjusted to experimental data. The aim of this paper is to not only mathematically prove the original Hermia model, but also to broaden the scope of this model for any real number n by using the original ODE, the equations of fluid mechanics and the properties of single and multivariable calculus. The final generalized Hermia model is given by a power-law for any n≠2 and is given by an exponential function at n=2 and can be fitted to ultrafiltration, microfiltration, nanofiltration and reverse osmosis data with acceptable values of R2 (>0.93). Here it is also shown that the accumulated volume as a function of time follows the same type of ODE. The values of n between the four original discreate values could be physically interpreted as the existence of new blocking mechanisms.
ARTICLE | doi:10.20944/preprints202112.0244.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: Attention mechanism; CHMM; LSTM; Multi-modal fusion; Human behavior recognition
Online: 14 December 2021 (15:09:15 CET)
The multi-modal data fusion method based on IA-net and CHMM technical proposed is designed to solve the problem that the incompleteness of target behavior information in complex family environment leads to the low accuracy of human behavior recognition.The two improved neural networks(STA-ResNet50、STA-GoogleNet)are combined with LSTM to form two IA-Nets respectively to extract RGB and skeleton modal behavior features in video. The two modal feature sequences are input CHMM to construct the probability fusion model of multi-modal behavior recognition.The experimental results show that the human behavior recognition model proposed in this paper has higher accuracy than the previous fusion methods on HMDB51 and UCF101 datasets. New contributions: attention mechanism is introduced to improve the efficiency of video target feature extraction and utilization. A skeleton based feature extraction framework is proposed, which can be used for human behavior recognition in complex environment. In the field of human behavior recognition, probability theory and neural network are cleverly combined and applied, which provides a new method for multi-modal information fusion.
CASE REPORT | doi:10.20944/preprints202110.0047.v1
Subject: Earth Sciences, Geophysics Keywords: shock waves; mechanism and dynamics of destruction; quartz; granites; calcite
Online: 4 October 2021 (11:03:20 CEST)
The spectra of the plasma emitted from the studied samples consist of several dozens of narrow bands superimposed on each other. Tables of spectral lines were used to interpret the spectra. It turned out that the largest number of bands corresponds to the radiation of positively charged ions and atoms of elements that make up the crystal lattices of minerals that make up the studied rocks. Thus, the spectra of the plasma emitted from quartz corresponded to the radiation of atoms and positively charged silicon ions, the charge of which varied from 1 to 4, as well as atoms and positively charged oxygen ions, the charge of which varied from 1 to 3. Positively charged ions and atoms of Si, O, K, Ca, Al and Na, which are part of the crystal lattices of quartz and feldspar, flew out of granites. Positively charged ions and Ca, C and O atoms flew out of the calcite.
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Vericiguat; osteoclast (OCs), MAPK, NF-κB; RANKL; AKT, molecular mechanism
Online: 8 September 2021 (13:02:05 CEST)
The nature of bone homeostasis is the coordination between the osteoblasts (OBs) and osteoclasts (OCs). However, abnormal activation of osteoclasts (OCs) could compromise the bone homeostasis. Thus, it is imperatively urgent to explore effective medical interventions for patients. NO/guanylate cyclase (GC)/cGMP signaling cascade has been widely reported in regulating bone metabolism, and GC plays a significantly critical role. Vericiguat, a novel oral soluble guanylate cyclase (sGC) stimulator, has been firstly reported in 2020 to treat patients with heart failure. However, the effect of Vericiguat on the function of OCs has not been explored. In this present study, we found that the concentration range of Vericiguat between 0-8uM was none- cytotoxic to BMMs. Vericiguat could enhance differentiation of OCs at concentration of 500nM, whereas it inhibited differentiation at 8 uM in terms of the number and size of OCs. In addition, Veirciguat also showed dural effect on RANKL‐induced OC fusion and bone resorption in a concentration‐dependent manner. Further, molecular assay suggested that the dually regulatory effect of Vericiguat on OCs was mediated by the bidirectional activation of IκB-α/NF-κB signaling pathway. Taken together, our present study demonstrated the dual effects of Vericiguat on the formation of functional OCs in a concentration-dependent manner. The regulatory effect of Vericiguat on OCs was mediated by the bidirectional activation of IκB-α/ NF-κB signaling pathway, and a potential balance between IκB-α/ NF-κB signaling pathway and sGC/cGMP/VASP may exist.
ARTICLE | doi:10.20944/preprints202107.0416.v1
Subject: Biology, Anatomy & Morphology Keywords: Epilepsy; VOCs; Attention seeking behaviours; Remote Odour Delivery Mechanism (RODM)
Online: 19 July 2021 (14:30:08 CEST)
Abstract Epilepsy is a disorder of the brain and a seriously debilitating condition, which has been associated with injury, social stigmatisation and in some cases, sudden unexpected and premature death. A sense of profound isolation is felt by many individuals with epilepsy, and this community has expressed an urgent desire for an early warning system to allow them time to prepare for seizure onset. Surveys of dog owners with epilepsy have previously reported that some dogs can predict the onset of a seizure. The current study used an experimental design to investigate the alleged propensity of untrained pet dogs to react to human epileptic seizures. We hypothesised that seizures are associated with specific volatile organic compounds resulting in detectable odours which are the biomarker that triggers these reported behavioural changes in the dogs. Here we provide details of the first empirical test to demonstrate that pet dogs display several significant behavioural changes when they are exposed to seizure-related odours that apparently emanate from their owners. Using a repeated measures design experiment, recordings were made of the reactions of 19 untrained pet dogs to odours from sweat samples provided by three people with epilepsy and by two people without epilepsy (controls). The seizure-associated sweat samples were captured pre-seizure, during seizure and post-seizure. All samples were randomly delivered to individual dogs in a test area, using two bespoke pieces of apparatus called Remote Odour Delivery Mechanisms (RODM). One RODM delivered only experimental odours, the other delivered only control odours. Behavioural changes by the dogs on encountering the odour samples were recorded by video for later analysis. Consistent with our hypothesis, seizure-associated odours evoked significant behavioural changes in the dogs which were affiliative in nature and directed at their owners.
ARTICLE | doi:10.20944/preprints202104.0247.v1
Subject: Life Sciences, Biochemistry Keywords: Rice-husk; power plants; CO2 emission reductions; Clean Development Mechanism
Online: 8 April 2021 (17:33:39 CEST)
The research is designed for developing the pilot small-scale clean development mechanism bundled project activities in Vietnam electricity/ energy sector. Its overall purpose is to assess the potential of rice husk - fuelled bio-power development projects in Mekong delta. Based on estimating the electricity potential of a bundle of rice husk-fuelled bio-power development projects in Mekong delta with the capacity of 11 MW per project, assessing their CO2 emission reductions (CERs) and CER credits, calculating and comparing their financial indices (NPV, B/C, IRR) in two cases: W/O CDM and W/CDM, the research expects to establish a rice husk energy balance flowchart for the whole Mekong delta in the year 2021 and recommend policies to use for bio-power generation the unused rice husk that is dumped and discharged from local paddy milling centers into rivers and canals, as well as, to put forward a safe and environmentally friendly solution to minimize thoroughly the current serious pollution of rivers and canals in Mekong delta with the increasing unused rice husk quantity in the context is where the sea level rise phenomenon is the strongest in the world .
REVIEW | doi:10.20944/preprints202102.0405.v1
Subject: Keywords: drug repurposing; antifungal therapy; antifungal mechanism; clinical application; antifungal agents
Online: 18 February 2021 (10:21:38 CET)
The morbidity and mortality caused by invasive fungal infections is increasing across the globe due to developments in transplant surgery, the use of immunosuppressive agents, and the emergence of drug-resistant fungal strains, which has led to a challenge in terms of treatment due to the limitations of three classes of drugs. Hence, it is imperative to establish effective strategies to identify and design new antifungal drugs. Drug repurposing is an effective way of expanding the application of existing drugs. In the last years, various existing drugs have been shown to be useful in the prevention and treatment of the invasive fungi. In this review, we summarize the currently used antifungal agents. In addition, the most up to date information on the effectiveness of existing drugs with antifungal activity is discussed. Moreover, the antifungal mechanisms of existing drugs are highlighted. These data will provide valuable knowledge to stimulate further investigation and clinical application in this field.
REVIEW | doi:10.20944/preprints202101.0151.v1
Subject: Life Sciences, Biochemistry Keywords: complement system; proteolytic cascade; convertase; inhibitor; structural biology; molecular mechanism
Online: 8 January 2021 (11:54:36 CET)
The complement system is part of the innate immune response, where it provides immediate protection from infectious agents and plays a fundamental role in homeostasis. Complement dysregulation occurs in several diseases, where the tightly regulated proteolytic cascade turns offensive. Prominent examples are atypical hemolytic uremic syndrome, paroxysmal nocturnal hemoglobinuria and Alzheimer’s disease. Therapeutic intervention targeting complement activation may allow treatment of such debilitating diseases. In this review, we describe a panel of complement targeting nanobodies that allow modulation at different steps of the proteolytic cascade, from the activation of the C1 complex in the classical pathway to formation of the C5 convertase in the terminal pathway. Thorough structural and functional characterization has provided a deep mechanistic understanding of the mode of inhibition for each of the nanobodies. These complement specific nanobodies are novel powerful probes for basic research and offer new opportunities for in vivo complement modulation.
ARTICLE | doi:10.20944/preprints202009.0029.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: diabetes mellitus; hypertension; obesity; Coronavirus; mechanism; COVID-19; viral interaction
Online: 2 September 2020 (05:37:46 CEST)
The pandemic of coronavirus disease (COVID-19), a disease caused by severe acute respiratory syndrome coronavirus 2 (SARSCoV-2), is causing substantial morbidity and mortality. Older age and presence of diabetes mellitus, hypertension and obesity significantly increases the risk for hospitalization and death in COVID-19 patients. In this Perspective, informed by the studies on SARS-CoV-2, Middle East respiratory syndrome (MERS-CoV), and the current literature on SARS-CoV-2, we discuss potential mechanisms by which diabetes modulates the host-viral interactions and host-immune responses. We hope to highlight gaps in knowledge that require further studies pertinent to COVID-19 in patients with diabetes mellitus, hypertension and obesity.
ARTICLE | doi:10.20944/preprints202007.0669.v1
Subject: Keywords: volt-ampere characteristics; battery mathematical model; mechanism function; fuel cell
Online: 28 July 2020 (09:39:10 CEST)
The corrected mechanism model of battery voltammetric function is helpful to guide the development and application of battery. There are two scientific issues that need to be answered: First, how many mechanisms do batteries have; Second, how to establish the mechanism model separately under the overlapping of these mechanisms. Volt-ampere characteristics of both linear state and nonlinear state exist; the monotonic decreasing of volt-ampere characteristics indicates that the battery have only three kinds of mechanisms. Without changing the basic form of the function and under the principle of the mechanism function’s working region considered, we propose a mechanism function which satisfies the monotonic decreasing characteristic of the voltammetric curve of battery, via the derivative law of each mechanism function in the voltammetric function of battery. By using the voltammetric data, the obtained cell mechanism function can accurately predict the potential (current or voltage) when the independent variable of the cell is zero, and provide the theoretical basis for the internal working mechanism of the cell, which can guide the practice.
REVIEW | doi:10.20944/preprints201902.0238.v1
Subject: Chemistry, Analytical Chemistry Keywords: hydride surface; silicon-carbon bond; aqueous normal phase; retention mechanism
Online: 26 February 2019 (11:33:15 CET)
The development of a stationary phase material for high performance liquid chromatography based on a surface of silica hydride as opposed to silanols on ordinary silica is discussed including synthetic approaches, characterization and applications. There are several synthetic approaches available to create a silica hydride surface. Modification of the Si-H moiety on the silica surface can be accomplished through use of a hydrosilation reaction. Both the intermediate silica hydride and the material modified with an organic moiety can be characterized by a number of spectroscopic as well as a variety of other methods. Further insights into the retention mechanism are provide through chromatographic measurements. The ultimate utility of any chromatographic stationary phase material is determined by its success for solving challenging analytical problems. A broad range of applications are reviewed to illustrate the versatility and usefulness of silica hydride-based stationary phases.
ARTICLE | doi:10.20944/preprints201804.0313.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: visual question answering; cross-modal multistep fusion network; attention mechanism
Online: 24 April 2018 (09:09:45 CEST)
Visual question answering (VQA) is receiving increasing attention from researchers in both the computer vision and natural language processing fields. There are two key components in the VQA task: feature extraction and multi-modal fusion. For feature extraction, we introduce a novel co-attention scheme by combining Sentence-guide Word Attention (SWA) and Question-guide Image Attention (QIA) in a unified framework. To be specific, the textual attention SWA relies on the semantics of the whole question sentence to calculate contributions of different question words for text representation. For the multi-modal fusion, we propose a “Cross-modal Multistep Fusion (CMF)” network to generate multistep features and achieve multiple interactions for two modalities, rather than focusing on modeling complex interactions between two modals like most current feature fusion methods. To avoid the linear increase of the computational cost, we share the parameters for each step in the CMF. Extensive experiments demonstrate that the proposed method can achieve competitive or better performance than the state-of-the-art.
ARTICLE | doi:10.20944/preprints201611.0097.v1
Subject: Social Sciences, Economics Keywords: forest industry and ecology; environmental capacity; interaction mechanism; SEM; PSIR
Online: 18 November 2016 (10:01:42 CET)
By introducing environmental mediator, for avoiding randomness in selecting indicators and subjectivity in deciding interaction path coefficients to reveal interaction mechanism among forest industry, ecology and environmental capacity, structural Pressure–State–Impact–Response (PSIR) and quantitative Structural Equation Modeling (SEM) are utilized with data on thirty–one provinces of China. We can find that: (i) forest industry has a negative influence on ecology, whereas ecology has a positive influence on industry; (ii) the destructive influence that industry has on ecology is much greater than the positive effect ecology has on industry; and (iii) environmental capacity plays a partial mediating role between industry and ecology. According to these results we can conclude that: (i) forest industry and ecology are not in a symbiotic relationship and have not reached a level of ecological security; (ii) the interaction between industry and ecology is in a period of transition from antagonistic to beneficial; and (iii) industry dominates ecology. However, we prospect the following advice: (i) methods of forest industry should be changed; (ii) new modes of industrial integration and circular economy should be developed; and (iii) the ability of the environment to sustain itself should be enhanced. The level of forest ecological security to discuss the symbiotic mechanism of industry and ecology will propose to be measured in future.
ARTICLE | doi:10.20944/preprints202206.0399.v1
Subject: Earth Sciences, Atmospheric Science Keywords: carbazole; OH radical; rate constants; oxidation mechanism; density functional theory (DFT)
Online: 29 June 2022 (08:19:43 CEST)
Carbazole is one of the typical heterocyclic aromatic compounds (NSO-HETs) observed in pol-luted urban atmosphere, which has become a serious environmental concern. The most im-portant atmospheric loss process of carbazole is the reaction with OH radical. The present work investigated the mechanism of OH-initiated atmospheric oxidation degradation of carbazole by using density functional theory (DFT) calculations at the M06-2X/6-311++G(3df,2p)//M06-2X/6-311+G(d,p) level. The rate constants were determined by the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The lifetime of carbazole determined by OH was compared with other typical NSO-HETs. The theoretical results show that the degradation of carbazole initiated by OH radical includes four types of reactions: OH additions to “bend” C atoms, OH additions to “benzene ring” C atoms, H abstractions from C-H bonds and the H ab-straction from N-H bond. The OH addition to C1 atom and the H abstraction from N-H bond are energetically favorable. The main oxidation products are hydroxycarbazole, dialdehyde, carba-zolequinone, carbazole-ol, hydroxy-carbazole-one and hydroperoxyl-carbazole-one. The calcu-lated overall rate constant of carbazole oxidation by OH radical is 6.52 × 10−12 cm3 molecule−1 s−1 and the atmospheric lifetime is 43.92 h under the condition of 298 K and 1 atm. The lifetime of carbazole determined by OH radical is similar with that of dibenzothiophene oxidation but longer than those of pyrrole, indole, dibenzofuran and fluorene. This work provides a better understanding of the reactivity of carbazole in the atmospheric environment, the formation of secondary organic aerosols, and the chemical degradation and removal of carbazole in the at-mospheric environment.
ARTICLE | doi:10.20944/preprints202206.0295.v1
Subject: Materials Science, Metallurgy Keywords: high entropy alloys; selective laser melting; microstructure; mechanical properties; strengthening mechanism
Online: 21 June 2022 (10:52:27 CEST)
The high entropy alloy (HEA) of equiatomic composition CrNiFeCoMn and with FCC crystal structure was additively manufactured with a selective laser melting (SLM) process starting from mechanically alloyed powders. The as produced alloy shows finenitride and phase pre-cipitates, which are Cr-rich and stable up to about 900 K. The precipitates increase in number and dimensions after long-period annealing at 900-1300 K, with a change in the HEA mechanical properties. Higher aging temperatures in furnace, above 1300 K, turn the alloy in a single FCC structure, with disappearance of the nitrate and phase precipitates inside the grains and at the grain boundaries, but with still a presence of a finer Cr-rich nitride precipitation phase. These re-sults suggest that the as-produced HEA is a supersatured solid solution at low and intermediate temperature with nitrides and nanostructures.
ARTICLE | doi:10.20944/preprints202202.0179.v2
Subject: Engineering, Mechanical Engineering Keywords: Ankle joint rehabilitation robot; Parallel mechanism; Statics analysis; Kinematics analysis; Workspace
Online: 18 February 2022 (13:06:23 CET)
In-depth research on the rehabilitation mechanism and motion characteristics of a rehabilitation training robot based on 4-UPUS parallel mechanism. The overall design and the working principle of each key component are explained, and the robot rehabilitation scheme is described. The static analysis and modal analysis of the robot bearing structure are carried out to verify whether the static mechanical characteristics of the mechanism meet the application requirements under working conditions.A simplified mathematical model of the six-bar linkage mechanism is established, and the kinematics of the mechanism is solved by the geometric analysis method. The motion characteristic diagram of each key point is obtained through simulation calculation. Establish the motion model of the parallel mechanism, and discuss the working space and motion performance analysis of the mechanism. The forward solution analysis of the mechanism position is carried out by using the numerical analysis method, and the three-dimensional graphics of the attitude angle and linear displacement of the reachable working space are obtained.Taking the UPUS single branch chain as the analysis object, the single open chain analysis method is used to solve the kinematics image of the corresponding surface in the working space of the mechanism, which verifies the correctness of the kinematics theoretical solution and the feasibility of simulation.The research results show that the 4-UPUS parallel mechanism rehabilitation training robot can cooperate with the ankle joint for rehabilitation training. It makes up for the single movement of the current lower limb rehabilitation robot and the unsatisfactory rehabilitation effect, and provides a reference for the practical application of the subsequent ankle joint rehabilitation robot system.
REVIEW | doi:10.20944/preprints202108.0578.v1
Subject: Materials Science, Other Keywords: Mo-Si-based alloys; alloying; rare earth elements; oxidation behavior; mechanism
Online: 31 August 2021 (15:58:50 CEST)
Traditional refractory materials such as nickel-based superalloys have been gradually unable to meet the performance requirements of advanced materials. The Mo-Si-based alloy, as a new type of high temperature structural material, has entered the vision of researchers due to its charming high temperature performance characteristics. However, its easy oxidation and even "pesting oxidation" at medium temperatures limit its further applications. In order to solve this problem, researchers have conducted large numbers of experiments and made breakthrough achievements. Based on these research results, the effects of rare earth elements like La, Hf, Ce and Y on the microstructure and oxidation behavior of Mo-Si-based alloys were systematically reviewed in the current work. Meanwhile, this paper also provided an analysis about the strengthening mechanism of rare earth elements on the oxidation behavior for Mo-Si-based alloys after discussing the oxidation process. Furthermore, the research focus about the oxidation protection of Mo-Si-based alloys in the future was prospected to expand the application field.
HYPOTHESIS | doi:10.20944/preprints202010.0004.v9
Subject: Biology, Anatomy & Morphology Keywords: carbon-based entity; driving force; energy; evolution; fitness; mechanism; natural selection; speciation; thermodynamics; theory
Online: 17 June 2021 (11:56:15 CEST)
It is desirable to upgrade previous evolutionary theories, which have remained incomplete and controversial for decades. Here we employ the concept of carbon-based entities (CBEs), which include methane, amino acids, proteins, organisms, and other entities containing relatively many carbon atoms. We deduce the driving force, mechanisms, steps, modes, tempos of CBE evolution, through integration of biology, physics, and chemistry using logics for complex issues. We hence establish the Carbon-Based Evolutionary Theory (CBET). The CBET suggests that evolution is the increase in hierarchy, diversity, fitness of CBEs under natural selection and driven by thermodynamics due to the chemical effect of the thermodynamic features of the Earth on CBEs. It provides better explanations for life origin, macroevolution events, natural selection, sympatric speciation, and evolution tempos than previous evolutionary theories. It reveals the evolutionary basis of multiple important social notions, including diversity, collaboration, altruism, obeying rules, and proper increase in freedom. It refutes some wrong notions in thermodynamics, including negative entropy (negentropy) and that biological order is equal to thermodynamic order, which have misled many people. The CBET is supported by its deduction and application. It could be a rare bridge linking laws of thermodynamics, evolution of life, and development of human society, and could have great significance in various sciences.
ARTICLE | doi:10.20944/preprints202009.0438.v1
Subject: Materials Science, Other Keywords: poly-ether-ether ketone; graphene oxide (GO); MoS2; tribological behaviours; mechanism
Online: 18 September 2020 (12:11:15 CEST)
Poly-ether-ether ketone (PEEK) is a great potential thermoplastic in industry and medical treatment and health. In this work, the PEEK/GO and PEEK/MoS2 composites were prepared by a novel hot isostatic pressing method. The addition of GO alters the tribological behaviours mechanism, fatigue wear mechanism is predominant to PEEK/GO composites. However, the combination of abrasive and adhesive wear mechanisms is observed for PEEK/MoS2 composites and PEEK. The reason is the hardness and tensile strength of composites are increased with the appropriate addition of GO. The response time to stable friction state of PEEK/GO and PEEK/MoS2 composites reduces in compared with PEEK, which conduce to shorten running-in time, reduce energy consumption and improve the tribological performances of composites. The addition of GO and MoS2 can effectively decrease the friction coefficient and wear rate, and the optimal content of GO and MoS2 was 0.7 wt.% and 15 wt.%, respectively. The results indicate that PEEK/GO and PEEK/MoS2 are impressive composites that possess super tribological properties.
ARTICLE | doi:10.20944/preprints202004.0544.v1
Subject: Biology, Ecology Keywords: ecological restoration; illegal mining; Clean Development Mechanism; carbon sequestration; carbon credits
Online: 30 April 2020 (17:24:36 CEST)
Ghana has had a long-standing problem of illegal gold mining that has led to the destruction of the environment. The government of Ghana is taking steps to not only curb illegal mining but also to restore destroyed lands that resulted from illegal mining. The government intends to spend financially in the area of ecological restoration to returned disturbed lands to their natural states possible, but the question remains whether restoring those disturbed lands will be beneficial to the country. The study was undertaken in Bekwai Municipal Area in the Ashanti region of Ghana where most locals are farmers. The research studies whether the benefits of ecological restoration outweigh the cost of ecological restoration? The research deployed a quantitative data collection. The data collected was analyzed using benefit-Cost ratio. The result shows that the benefit of ecological restoration outweighs the cost incurred as dependent on the land use as a carbon sequestration project. In conclusion, investment in ecological restoration is a step in the right direction for a country endowed with gold resources. This will spur growth and at the same time improve and protect the country’s natural resources and environment.
REVIEW | doi:10.20944/preprints202003.0274.v1
Subject: Keywords: Calcium-signaling; inositol-trisphosphate; IP3-mechanism; intracellular-pH; [Ca2+]i; proton.
Online: 17 March 2020 (09:14:03 CET)
36 years after the publication of the important article by Busa and Nuccitelli on the variability of intracellular pH (pHi) and the interdependence of pHi and intracellular Ca2+ concentration ([Ca2+]i), little research has been carried out on pHi and calcium signaling. Moreover, the results appear to be contradictory. Some authors claim that the increase in [Ca2+]i is due to a reduction in pHi, others that it is caused by an increase in pHi. The reasons for these conflicting results have not yet been discussed and clarified in an exhaustive manner. Variations in pHi have a significant impact on the increase in [Ca2+]i and hence on some of the basic biochemical mechanisms of calcium signaling. This paper focuses on the possible triggering role of protons, highlighting the mechanisms potentially involved and the open issues that could be clarified by research.
REVIEW | doi:10.20944/preprints202002.0209.v1
Subject: Life Sciences, Molecular Biology Keywords: bone morphogenetic protein 4; molecular mechanism; delivery; clinical application; malignant glioma
Online: 16 February 2020 (04:19:22 CET)
Malignant gliomas are heterogeneous neoplasms. Glioma stem-like cells (GSCs) are undifferentiated and self-renewing cells that develop and maintain these tumors. These cells are the main population that resist current therapies. Genomic and epigenomic analyses has identified various molecular subtypes. Bone morphogenetic protein 4 (BMP4) reduces the number of GSCs through differentiation and induction of apoptosis, thus increasing therapeutic sensitivity. However, the short half-life of BMP4 impedes its clinical application. We have previously reviewed BMP4 signaling in central nervous system development and glioma tumorigenesis and its’ potential as a treatment target in human gliomas. Recent advances in understanding both adult and pediatric malignant gliomas highlight critical roles of BMP4 signaling pathways in the regulation of tumor biology, and indicate its’ potential as a therapeutic molecule. Furthermore, significant progress has been made on synthesizing BMP4 biocompatible delivery materials, which can bind to and markedly extend BMP4 half-life. Here, we review current research associated with BMP4 in brain tumors, especially in pediatric malignant gliomas. We also summarize BMP4 delivery strategies, with a focus on biocompatible BMP4 binding peptide amphiphile nanostructures as promising novel delivery platforms for treatment of these devastating tumors.
ARTICLE | doi:10.20944/preprints201808.0416.v1
Subject: Keywords: hexapod walking robot; 3-UPU parallel mechanism; kinematics; stability; gait planning
Online: 23 August 2018 (13:31:36 CEST)
The paper presents an innovative hexapod walking robot built with 3-UPU parallel mechanism. In the robot, the parallel mechanism is used as both an actuator to generate walking and also a connecting body to connect two groups of three legs, thus enables the robot to walk with simple gait by very few motors. In the paper, the forward and inverse kinematics solutions are obtained. The workspace of the parallel mechanism is analyzed using limit boundary search method. The walking stability of the robot is analyzed, which yields the robot’s maximum step length. The gait planning of the hexapod walking robot is studied for walking on both flat and uneven terrains. The new robot, combining the advantages of parallel robot and walking robot, has a large carrying capacity, strong passing ability, flexible turning ability, and simple gait control for its deployment for uneven terrain.
ARTICLE | doi:10.20944/preprints201808.0354.v1
Subject: Materials Science, Nanotechnology Keywords: ZnO; NiO loading; p-n heterojunction; nanofiber; gas sensor; sensing mechanism
Online: 20 August 2018 (12:26:21 CEST)
Metal oxide p-n heterojunction nanofibers (NFs) are among the most promising approaches to enhancing the efficiency of gas sensors. In this paper, we report the preparation of a series of p-NiO-loaded n-ZnO NFs, namely (1 − x) ZnO-xNiO (x = 0.03, 0.05, and 0.1 wt%), for hydrogen gas sensing experiments. Samples were prepared through the electrospinning technique followed by a calcination process. The sensing experiments showed that the sample with 0.05 wt% NiO loading resulted in the highest sensing performance at an optimal sensing temperature of 200 °C. The sensing mechanism is discussed in detail and contributions of the p-n heterojunctions, metallization of ZnO and catalytic effect of NiO on the sensing enhancements of an optimized gas sensor are analyzed. This study demonstrates the possibility of fabricating high-performance H2 sensors through the optimization of p-type metal oxide loading on the surfaces of n-type metal oxides.
ARTICLE | doi:10.20944/preprints201806.0192.v1
Subject: Life Sciences, Biotechnology Keywords: β4-galactosyltransferase 4; transcriptional mechanism; sensor cells; colon cancer; drug screening
Online: 12 June 2018 (12:51:07 CEST)
The increased expression of β4-galactosyltransferase (β4GalT) 4 was closely associated with poor prognosis of colon cancer. Recently, we showed that the expression of the β4GalT4 gene is regulated by the 0.17 kb core promoter region containing one binding site for Specificity protein 1 (Sp1). To develop a novel screening method for anti-colon cancer drugs, two sensor cell lines having the luciferase gene under the control of two β4GalT4 gene promoters that differed in length were established from SW480 human colon cancer cells. The hGT4-0.17-sensor cells possessed the luciferase reporter driven by the 0.17 kb promoter, while the hGT4-0.3-sensor cells possessed the luciferase reporter driven by the 0.3 kb promoter containing one binding site each for colon cancer-related transcription factors including activator protein 2, E2F, caudal-related homeobox transcription factors, and Runt-related transcription factors besides Sp1. Upon treatment with mitogen-activated protein kinase inhibitor U0126, the promoter activities of the hGT4-0.3-sensor cells decreased significantly, while those of the hGT4-0.17-sensor cells unchanged. These results suggest that the responsiveness to U0126 differs between two sensor cell lines due to the different regulation of the luciferase reporters. This study provides the novel screening method for anti-colon cancer drugs by the combination of two sensor cell lines.
COMMUNICATION | doi:10.20944/preprints201710.0106.v1
Subject: Materials Science, Other Keywords: graphene-doped porous silicon; p-type silicon; hydrogen sensor; sensing mechanism
Online: 16 October 2017 (08:00:59 CEST)
In this study, a graphene-doped porous silicon (G-doped/p-Si) substrate for low ppm H2 gas detection by an inexpensive synthesis route was proposed as a potential noble graphene-based gas sensor material and to understand the sensing mechanism. The G-doped/p-Si gas sensor was synthesized by a simple capillary force-assisted solution dropping method on p-Si substrates, whose porosity was generated through an electrochemical etching process. G-doped/p-Si was fabricated with various graphene concentrations and exploited as a H2 sensor operated at room temperature. The sensing mechanism of the sensor with/without graphene decoration on p-Si was proposed to elucidate the synergetic gas sensing effect generated from the interface between the graphene and p-type silicon.
ARTICLE | doi:10.20944/preprints201704.0030.v1
Subject: Mathematics & Computer Science, Artificial Intelligence & Robotics Keywords: Automatic localization; human visual mechanism; superpixel contrast feature; ultrasound breast tumor.
Online: 5 April 2017 (15:50:40 CEST)
Human visual system (HVM) can quickly localize the most salient object in scenes, which has been widely applied on natural image segmentation -. In ultrasound (US) breast images, compared with background areas, tumor is more salient because of its higher contrast. In this paper, we develop a novel automatic localization method based on HVM for automatic segmentation of ultrasound (US) breast tumors. First, the input image is smoothed by convolution with a linearly separable Gaussian filter and then subsampled into a 9-layer Gaussian pyramid. Then intensity, blackness ratio, and superpixel contrast features are combined to compute saliency map, in which Winner Take All algorithm is used to localize the most salient region, presenting with a circle on the localized target. Finally the circle is taken as the initial contour of CV level set to finish the extraction of breast tumor. The localization method has been tested on 400 US beast images, among which 378 images have higher saliency than background areas and succeed in localization, with high accuracy 92.00%. The HVM localization method can be used to localize the tumors, combined with this method, CV level set can achieve the fully automatic segmentation of US breast tumors. By combing intensity, blackness ratio and superpixel contrast features, the proposed localization method can successfully avoid the interference caused by background areas with low echo and high intensity. Moreover, multi-object localization of US breast images can be considered in future employment.
ARTICLE | doi:10.20944/preprints202206.0396.v1
Subject: Social Sciences, Economics Keywords: Fuzzy Logic; Global optimization; Mechanism design; Game theory; Artificial inference; Global learning
Online: 29 June 2022 (05:22:14 CEST)
This paper aims to introduce an overview of several aspects of the so-called Artificial Intelligence, their potential impacts on economic and social dimen- sions, and suggestions for possible approaches of investiment based upon effective and mature techniques. In this fashion, it is important to address from educational and academic issues to industrial densities and profiles, rel- atively to a given region, country or continent. Even etymological adequacy and psychological consequences of the denomination ”Artificial Intelligence” need some reflection, and suggestions for a lucid replacement are presented. In addition, suggestions about how can specific firms choose the right type of technique in order to improve profit and organizational efficiency. After all, what are the main transformations needed to amplify gains and structural improvements from the use of higher level technological mecha- nisms? Which connections can be established between the pillars of evolu- tionary economics and this field of knowledge? Which institutional contexts are able to benefit from AI tools, inducing constructive externalities to firms in terms of education, technical and scientific skills upgrading, so as to reach higher levels of employment in the long term and limit unemployment in the short one? Which branches of the so-called Artificial Intelligence are best suited to which types of activities? This work aims to contribute in the search for answers to these questions.
ARTICLE | doi:10.20944/preprints202206.0087.v2
Subject: Social Sciences, Sociology Keywords: public sports service; new urbanization; development dynamic relationship; interaction mechanism; optimal path
Online: 8 June 2022 (10:19:08 CEST)
In the new period, the state has made every effort to promote the new urbanization of public sports service. Entropy method, coupled coordination model, cold hot spot analysis is used to explore the dynamic relationship between public sports services and the development of new urbanization in China from 2008 to 2017. The results show that: (1) The development of the internal subsystem of public sports service is not balanced, the sports financial investment system grows rapidly, but the development of professional sports talent team is slow. (2) The imbalance of regional development cannot be ignored, and the public sports service level shows a decreasing gradient from east to west. (3) The regional development features are different. The eastern region is dominated by the coordinated development of sports public service and urbanization, while the central region is mainly in the type of public sports service lag, while the western region has multiple complex characteristics of low-level coordination and public sports service lag. Therefore, it is proposed that the construction of modern public sports service system should be investigated in the context of the development of new urbanization. It should be promoted from the following aspects: promoting the extension of public sports service to rural areas, engendering the "citizen's right" of sports health to the migrant population, conforming to the trend of mass sports intelligence, developing green sports and revitalizing idle sports assets in cities.
ARTICLE | doi:10.20944/preprints202201.0115.v1
Subject: Physical Sciences, General & Theoretical Physics Keywords: de Broglie phase; de Sitter geometry; micro-cosmology; third quantization; Higgs mechanism
Online: 10 January 2022 (12:58:36 CET)
A theoretical description of quantum jumps at the level of elementary particles is proposed, based on a micro-cosmological interpretation of their de Broglie phase. The third quantization formalism proposed in current literature for the description of baby universes in quantum cosmology is used here to describe the breakdown of unitarity in the transition from the pre-jump to the post-jump wave function. The corpuscular aspect manifested by the particle in the micro-interaction that originates the jump is represented by a pair of evanescent "micro-universes", respectively pre- and post-jump, connected by a wormhole. The latter represents the actual implementation of the interaction that leads to the projection on the outgoing state; this interaction is always local, even when the selected outgoing state is entangled. Therefore, the decoherence which leads to the emergence of classicality is originated by the same fundamental interactions of the Standard Model involved in the unitary evolution of the wave function. The objective nature of the reduction process admits implications on the possibility of using the formalism in the cosmological context, which are briefly discussed.
ARTICLE | doi:10.20944/preprints201703.0184.v1
Subject: Engineering, Mechanical Engineering Keywords: MEMS S&A device; centrifugal insurance mechanism; nonlinear dynamic method; parametric study
Online: 24 March 2017 (10:04:55 CET)
MEMS (Micro-electromechanical Systems) becomes important increasingly due to the smarter and smaller fuze used in OICW (Objective Individual Combat Weapon). MEMS Safety and Arming (S&A) device is employed in different platforms and regions for small caliber projectile. Therefore, it is necessary to make a parametric study of the MEMS S&A device in different apply environments and explore the main sensitive factors of the MEMS S&A device to provide reference for designs. In this paper, based on the MEMS S&A device designed by our term, theory and finite element models are established, and the centrifugal insurance mechanism of the MEMS S&A device is parametric studied under the different speeds, temperature and thickness of the model by nonlinear dynamic method. By comparing the experimental and predicted results, the established FEM model is verified, and the conclusion is that the temperature and the centrifugal force are the main sensitive factors in the centrifugal insurance mechanism. In summary, we can suggest that the application environment, which the MEMS S&A device is suitable for, is the temperature equal to or slightly greater than normal temperature and the rotating speed higher than35000r/min of small caliber projectile.
ARTICLE | doi:10.20944/preprints202206.0390.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: Object detection; Feature fusion network; Multiple feature selection; Angle prediction; Pixel Attention Mechanism
Online: 29 June 2022 (03:09:52 CEST)
The object detection task is usually affected by complex backgrounds. In this paper, a new image object detection method is proposed, which can perform multi-feature selection on multi-scale feature maps. By this method, a bidirectional multi-scale feature fusion network is designed to fuse semantic features and shallow features to improve the detection effect of small objects in complex backgrounds. When the shallow features are transferred to the top layer, a bottom-up path is added to reduce the number of network layers experienced by the feature fusion network, reducing the loss of shallow features. In addition, a multi-feature selection module based on the attention mechanism is used to minimize the interference of useless information on subsequent classification and regression, allowing the network to adaptively focus on appropriate information for classification or regression to improve detection accuracy. Because the traditional five-parameter regression method has severe boundary problems when predicting objects with large aspect ratios, the proposed network treats angle prediction as a classification task. The experimental results on the DOTA dataset, the self-made DOTA-GF dataset and the HRSC 2016 dataset show that, compared with several popular object detection algorithms, the proposed method has certain advantages in detection accuracy.
ARTICLE | doi:10.20944/preprints202111.0115.v1
Subject: Physical Sciences, Particle & Field Physics Keywords: Mach's principle; GR; Borsuk-Ulam theorem; topology; Page and Wootters mechanism; dimensional anisotropy
Online: 5 November 2021 (10:58:49 CET)
We create a model universe by equipping a topological surface (system) with compact dimensions insulated by an information blocking horizon. The insulated compact WF can produce entanglement independent of distance. Interaction between the system and the WF changes the curvature of the first and the quantum state (frequency) of the second in an interconnected relationship. Thus, the field curvature measures the evolution of the particle WF as time. Positive field curvature creates pressure, whereas negative field curvature generates a vacuum, satisfying the Borsuk-Ulam Theorem and the Page and Wootters mechanism of static time. The accumulation of pressure or vacuum generates poles with contrasting dimensionalities, two-dimensional black hole horizons (time infinite), and four-dimensional cosmic voids (time zero). The orthogonality of the field and the compact WF give rise to global self-regulation that fine-tunes the cosmic parameters and can promote fractal topology. The four-dimensional vacuum in cosmic voids can produce an accelerating expansion without dark energy. When gravity effects are eliminated, we find a new, so far unexplored, order-increasing side of entropy. The verifiable and elegant hypothesis satisfies Mach's principle.
ARTICLE | doi:10.20944/preprints202109.0381.v1
Subject: Engineering, Mechanical Engineering Keywords: double ceramic coating; arc aluminum plating; stress; protection mechanism; finite element sim-ulation
Online: 22 September 2021 (11:52:46 CEST)
To understand the enhanced protection mechanism of CoCrNiAlY-YSZ-LaMgAl11O19 dou-ble-layer ceramic coating with aluminum plating, a finite element simulation method was used to simulate the distribution of thermal stress in the coating in all directions. The results show that in the air exposure of the un-aluminized coating, high temperature causes a large radial thermal stress on the surface of the LaMgAl11O19 (LMA) layer, and it increases with the increase in temperature, which is the main reason for the initiation of axial cracks. After arc aluminum plating, the aluminum plating layer effectively inhibited the volume shrinkage of the coating through good adhesion to the coating and internal diffusion, the thermal stress of the coating was considerably reduced, and the CoCrNiAlY-YSZ-LMA coating had an effective enhancement and protection effect; however, there was still a certain amount of shear thermal stress inside the LMA layer, the top of the crack, and the bottom of the crack. This thermal stress caused the initi-ation of radial microcracks in the LMA layer, which also becomes a risk point for the failure of the aluminum coating.
ARTICLE | doi:10.20944/preprints202101.0515.v1
Subject: Physical Sciences, Acoustics Keywords: Entropy; Black hole physics; Radiation mechanism: thermal; Relativity; Methods: analytical; Astronomical databases: miscellaneous
Online: 25 January 2021 (15:32:41 CET)
Is it possible to quantify in General Relativity, GR, the entropy generated by supermassive black holes, BHs, during its evaporation time, since the intrinsic Hawking radiation in the infinity that, although insignificant, is important in the effects on the thermal quantum atmosphere?The purpose was to develop a formula that allows us to measure the entropy generated during the evaporation time of different types of BHs of: i. remnant BH of the binary black holes’ merger, BBH: GW150914, GW151226 and LTV151012 detected by the Laser Interferometer Gravitational-Wave Observatory (LIGO), and ii. Schwarzschild, Reissner-Nordström, Kerr and Kerr-Newman, and thus quantify in GR the “insignificant” quantum effects involved, in order to contribute to the validity of the generalized second law (GSL) that directly links the laws of black hole mechanics to the ordinary laws of thermodynamics, as a starting point for unifying quantum effects with GR. This formula could have some relationship with the detection of the shadow’s image of the event horizon of a BH.This formula was developed in dimensional analysis, using the constants of nature and the possible evaporation time of a black hole, to quantify the entropy generated during that time. The energy-stress tensor was calculated with the 4 metrics to obtain the material content and apply the proposed formula.The entropy of the evaporation time of BHs proved to be insignificant, its temperature is barely above absolute zero, however, the calculation of this type of entropy allows us to argue about the importance of the quantum effects of Hawking radiation mentioned by authors who have studied the quantum effects with arguments that are fundamentally based on the presence of the surrounding thermal atmosphere of the black hole.
ARTICLE | doi:10.20944/preprints202009.0283.v1
Subject: Life Sciences, Molecular Biology Keywords: Decapod Crustaceans; dsRNA transport; Gene silencing mechanism; Serum dsRNA binding proteins; Systemic RNAi
Online: 13 September 2020 (12:09:03 CEST)
RNA interference (RNAi) has become a widely utilised method to study gene function, yet despite this, many of the mechanisms surrounding RNAi remain elusive. The core RNAi machinery is relatively well understood, however many of the systemic mechanisms, particularly double stranded RNA (dsRNA) transport, are not. Here, we demonstrate that dsRNA binding proteins in the serum contribute to systemic RNAi, and may be the limiting factor in RNAi capacity for species such as spiny lobsters where gene silencing is not functional. Incubating serum from a variety of species across phyla with dsRNA led to a gel mobility shift in species where systemic RNAi has been observed, with this response being absent in species where systemic RNAi has never been observed. Proteomic analysis suggested lipoproteins may be responsible for this phenomenon, and may transport dsRNA to spread the RNAi signal systemically. Following this, we identified the same gel shift in the slipper lobster Thenus australiensis and subsequently silenced the insulin androgenic gland hormone, marking the first time RNAi has been performed in any lobster species. These results pave the way for inducing RNAi in spiny lobsters, and better understanding the mechanisms of systemic RNAi in Crustacea, as well as across phyla.
ARTICLE | doi:10.20944/preprints201912.0005.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: motivational mechanism; labor interests; personnel selection; adaptation and training; the structure of interests
Online: 2 December 2019 (04:46:36 CET)
The issue of actualization of labor interests as a motivational driver and one of the sources of labor productivity is little-studied in applied and organizational psychology. The study given in the paper fills some “blanks” of this problem. The leading approach to research is the motivational system proposed on the basis of theoretical analysis and the developed psychological model of labor interests. Using the methods of a special survey, questioning and interview guides, the analysis and comparative assessment of the labor interests of 50 candidates for the service manager position (entertainment and restaurant industry field) was conducted; as well as of 45 employees in this industry aged 18 to 25. The main results of the paper show the connection of labor interests with the company's personnel management system, namely with the processes of selection, adaptation, and training. It was revealed that the candidates selected for the service manager position were of primary group interest and financial incentive was secondary. At the same time, financial incentive contributed to the successful passage of the adaptation period. Occupational interests of employees depended on their education and job specifics. Career interests were influenced by the time spent with the company. The recommendations necessary for employers to create the conditions corresponding to the leading labor interests of employees were substantiated.
ARTICLE | doi:10.20944/preprints201903.0103.v2
Subject: Physical Sciences, Particle & Field Physics Keywords: charged dark matters; left-handed neutrinos; Higgs mechanism, universe evolution; extended standard model
Online: 15 April 2019 (12:53:22 CEST)
In the present work, the charged dark matters of B1, B2 and B3 bastons are explained as the right-handed partners of the left-handed neutrinos. The new Higgs mechanism of SU(2)DM×SU(2)Weak×SU(2)Strong including electromagnetic and gravitational forces is applied. And the rest masses of the elementary particles depend on their charge configurations. The left-handed neutrinos have only the lepton charges (LC) and the right-handed dark matters have only the electric charges (EC). This explains the fact that the rest masses of the left-handed neutrinos are so small, and the rest masses of the right-handed dark matters are relatively very large. The proposed rest mass (26.12 eV/c2) of the B1 dark matter is indirectly confirmed from the supernova 1987A data. The missing neutrinos are newly explained by using the dark matters and lepton charge force. The neutrino excess anomaly of the MinibooNE data is explained by the B1 dark matter scattering within the Cherenkov detectors. The quark mixing and neutrino mixing are not required in the present model. It is shown that our matter universe and its partner antimatter universe can be created from the big bang in the point of view of time -, charge -, space -, and quantum state – symmetric universe evolution.
ARTICLE | doi:10.20944/preprints201902.0237.v1
Subject: Chemistry, General & Theoretical Chemistry Keywords: PCTA/PT/DTs; formation mechanism; radical/molecule coupling; density functional theory; rate constant
Online: 26 February 2019 (11:29:37 CET)
Polychlorinated phenoxathiins (PCPTs), polychlorinated dibenzothiophenes (PCDTs), and polychlorinated thianthrenes (PCTAs) are sulfur analogues of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/DFs). Chlorothiophenols(CTPs) and chlorophenols (CPs) are key precursors to form PCTA/PT/DTs, which can form chloro(thio)phenoxy radical, sulfydryl/hydryl-substituted phenyl radical and (thio)phenoxyl diradicals. The available radical/radical PCTA/DT formation mechanism failed to explain the higher concentration of PCDTs than that of PCTAs under the pyrolysis or combustion conditions. Thus in this work, a detailed thermodynamics and kinetic calculations were carried out to investigate the pre-intermediates formation for PCTA/PT/DTs from radial/molecule coupling of 2-C(T)P with their key radical species. Our study found that the radial/molecule mechanism can thermodynamically and kinetically contribute to the gas-phase formation of PCTA/PT/DT/s. The S/C coupling modes to form thioether-(thio)enol intermediats are preferable over the O/C coupling modes to form ether-(thio)enol intermediats. Thus, although the radial/molecule coupling of chlorophenoxy radical with 2-C(T)P have no effect on the PCDD/PTs formation, the radial/molecule coupling of chlorothiophenoxy radical with 2-C(T)P play an important role in the PCDT/PT formation. Most importantly, the pre-PCDT intermediates formation pathways from the coupling of sulfydryl/hydryl-substituted phenyl radical with 2-C(T)P and the coupling of (thio)phenoxyl diradicals with 2-C(T)P are more favorable to pre-PCTA/PT intermediates formation pathways from the coupling of chlorothiophenoxy radical with 2-C(T)P, which can give reasonable explanation for the high PCDT-to-PCTA ratio in the environment.
ARTICLE | doi:10.20944/preprints201901.0329.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: non-thermal plasma; charcoal gasification; carbon conversion; hydrogen release; reaction kinetics; reaction mechanism
Online: 31 January 2019 (14:20:08 CET)
The motivation of this work is to investigate experimentally the influence of non-thermal plasma (NTP) application on the reaction kinetics of atmospheric pressure steam gasification of charcoal using a thermostatically controlled drop tube reactor. A gliding-arc generator provides about 1 kW electrical power NTP. For comparison thermal gasification is investigated under comparable flow and specific energy input conditions providing additional heat to the steam. Optical temperature measurement 20 cm flow down of the NTP zone is utilized to characterize the specific enthalpy of the reactive flow. The composition of produced syngas is measured by a gas analyzer and used for the calculation of gas flow rates. The results show a NTP-enhancement on the production of individual syngas components (H2, CO, CH4), especially on hydrogen production by around 39%. The syngas-based carbon conversion and hydrogen release are calculated from the carbon and hydrogen balance between the correspondent content in syngas and in the feedstock. The NTP promoted the carbon conversion and hydrogen release by 25% and 31%, respectively. The first-order reaction kinetics are determined by data-fitting in an Arrhenius diagram. The plasma enhanced the reaction rate coefficients by 27%. Based on experimental results and other literature, possible plasma-induced reactions are proposed.
ARTICLE | doi:10.20944/preprints201810.0511.v1
Subject: Social Sciences, Organizational Economics & Management Keywords: Bio-economy; Agricultural by-product; Horizontal coordination; Contract mechanism; Choice model; Waste valorization
Online: 22 October 2018 (16:11:55 CEST)
Efficient use of agricultural wastes and by-products, basically transforming waste materials into value added products, is considered as pivotal for an effective bioeconomy strategy for the rural development. To this scope, citrus waste management represents a major issue for citrus processors but, at the same time, it embodies a potentially unexploited resource for the rural sustainable development. This study focuses on analyzing the current management of citrus waste in South Italy and identifying the determinants and barriers that may affect an entrepreneur’s choice on the destination of citrus waste. Citrus processors’ preferences about the contract characteristics needed to take part in a co-investment scheme have been investigated. Both analyses are preliminary steps to design an innovative and sustainable citrus by-product supply chain. Results show that the distance between the citrus processors and the citrus by-products plant is one of the main criteria for choosing alternative valorization pathways. Moreover, the required guaranteed capital, the short duration of the contract, and low risk are contract scheme characteristics that improve entrepreneurs’ willingness to co-invest in the development of a citrus waste multifunctional plant.
REVIEW | doi:10.20944/preprints201810.0128.v1
Subject: Chemistry, Organic Chemistry Keywords: amide resonance; anomeric effect; HERON reaction; pyramidal amides; physical organic chemistry; reaction mechanism
Online: 8 October 2018 (05:45:12 CEST)
This review describes how resonance in amides is greatly affected upon substitution at nitrogen by two electronegative atoms. Nitrogen becomes strongly pyramidal and resonance stabilisation, evaluated computationally, can be reduced to as little as 50% that of N,N-dimethylacetamide. However, this occurs without significant twisting about the amide bond, which is borne out both experimentally and theoretically. In certain configurations, reduced resonance and pronounced anomeric effects between heteroatom substituents are instrumental in driving the HERON (Heteroatom Rearrangement On Nitrogen)† reaction, in which the more electronegative atom migrates from nitrogen to the carbonyl carbon in concert with heterolysis of the amide bond, to generate acyl derivatives and heteroatom-substituted nitrenes. In other cases the anomeric effect facilitates SN1 and SN2 reactivity at the amide nitrogen.
ARTICLE | doi:10.20944/preprints201712.0189.v1
Subject: Materials Science, Nanotechnology Keywords: micro/nano-structured alloy; mechanical properties; in-situ tensile; deformation mechanism; research progress
Online: 27 December 2017 (06:39:22 CET)
Metal and alloy toughening was the core and long-term research direction in materials filed. As grain size had bimodal distribution, micro/nano-structured alloys presented excellent comprehensive mechanical properties, and this had become one of the research hotspots and developing trends in the field of nanotechnology. In-situ tensile test was a direct and effective method to study the deformation mechanism of materials, which revealed the multiple mechanisms responding to feature grain sizes and provided reliable experimental means and research technique. Research on development of in-situ technique and its applications in mechanical properties was reviewed in this paper according to the recent advances on the modern mechanical properties for high strength and high plasticity alloy at home and abroad. The disadvantages of the present study of preparation methods and investigation techniques for high-performance alloy had been concluded. Finally, the development prospects of high strength and high plasticity alloy materials were analyzed.
ARTICLE | doi:10.20944/preprints201709.0154.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: penetration enhancement effect; molecular mechanism; coarse grain molecular dynamics; menthol; borneol; 5-FU
Online: 29 September 2017 (12:39:49 CEST)
Borneol and menthol were two terpenes wildly used as penetrate enhancer in transdermal drug delivery. To explore their penetration enhancement effect towards hydrophilic drug, 5-FU was selected as model drug. A method combined vitro permeation studies and coarse grain molecular dynamics was used to investigate their penetration enhancement effect towards 5-FU. As a result, although both borneol and menthol showed a penetration enhancement effect towards 5-FU, they differed a lot in the penetration enhancement mechanism, which was also thought to account for their different penetration enhancement effect. As for menthol, SC bilayer disrupting effect seemed to be its main mechanism. While for borneol, its mechanism seemed to be more complicated. Except for disrupting the SC bilayer, it could also increase the permeation of 5-FU by enhancing the diffusion rate of 5-FU or inducing the formation of transient pore. All of this enable us a molecular understanding of borneol and menthol’s penetration enhancement effect towards hydrophilic drug, which might provide some guidance in the latter research and application.
ARTICLE | doi:10.20944/preprints201612.0082.v1
Subject: Chemistry, Medicinal Chemistry Keywords: transdermal physical penetration technology; Fu’s Cupping Therapy; pharmacokinetics; SEM; TEM; stratum corneum; mechanism
Online: 15 December 2016 (10:57:46 CET)
Background: in this paper, a new physical penetration technology for transdermal administration with traditional Chinese medicine (TCM) characteristics - Fu’s cupping therapy (FCT) - was established and studied by in-vitro and in-vivo experiments; the penetration effect and mechanism of FCT physical penetration technology (FCT-PPT) was preliminarily discussed. Method: Indomethacin (IM) as a model drug，by transdermal in vitro tests the establishment of the high，medium and low reference were finished as the chemical permeation system；chemical penetration enhancers and iontophoresis as a reference，the percutaneous penetration effect of FCT for IM patch was evaluated with 7 species diffusion kinetics model and in vitro drug distribution；naproxen as an internal standard，using UPLC-MS/MS technology，the IM quantitative analysis method in vivo was established，and pharmacokinetic parameters (AUC0-t，AUC0-∞，AUMC0-t，AUMC0-∞, Cmax and MRT) as indicators were used evaluate to FCT penetration role in vivo；in the same time，the group used 3K factorial design to study joint synergistic penetration effect on FCT and chemical penetration enhancers (CPEs)；by SEM and TEM，the skin micro and ultrastructural changes of the stratum corneum (SC) surface were observed, to explore pay tank penetration mechanism. Results: In vitro and in-vivo skin permeation experiments revealed that both the total cumulative percutaneous amount and in-vivo percutaneous absorption amount (AUC and AUMC) of indomethacin that permeated SD mouse skin using FCT techniques were greater than the amount observed using CPE and iontophoresis: Firstly, in contrast to the control group, the indomethacin percutaneous rate (PR) of the FCT lower group (FCTL) was 35.52%, and the enhancement ratio (ER) at 9h was 1.76X, which was roughly equivalent to the penetration enhancing effect of the CPEs and iontophoresis; secondly, the indomethacin PR of the FCT middle (FCTM) group and the FCT high intensity group (FCTH) were respectively 47.36% and 54.58%, ER at 9h were separately 3.58X and 8.39X; thirdly, pharmacokinetic studies showed that in-vivo indomethacin percutaneous absorption of the FCTs was higher than that of the control group, that of the FCTM group was slightly higher than that of the CPEs group, and that of the FCTM group was significantly higher than that of the others. Meanwhile, the variance analysis indicated that the combination of the FCT penetration enhancement method and the CPE method had beneficial effects in penetration enhancing of the skin: the significance level of the CPE method was 0.0004, which was apparently lower than the 0.001, meaning the difference was markedly significant; the significance level of the FCT was under 0.0001, its difference markedly significant; and the significance level of factor interaction A×B was lower than 0.0001, indicating that its difference of the synergism was markedly significant. Moreover, SEM and TEM images showed that the SC surfaces of SD rats treaded with FCT-PPT was damaged, and hard to observe the complete surface structure with its SC pores growing bigger and its special “brick structure” becoming looser, indicating that it broke the barrier function of skin, which revealed potentially a major route of skin penetration. Conclusion: FCT, as percutaneous penetration new technologies, has penetration effects significantly, with Chinese characteristics and highly clinical value, worth promoting development.
ARTICLE | doi:10.20944/preprints202201.0286.v3
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: novel ncRNAs; DE landscape; LSCs and LTCs; LncRNA; MiRNA; CircRNA; ceRNA networks; molecular mechanism
Online: 4 August 2022 (16:29:49 CEST)
ALDH+ H1975 lung adenocarcinoma stem cells (LSCs) are a rare cell population identified in lung adenocarcinoma (LUAD). LSCs can self-renew, drive tumor initiation, growth, metastasis, and recurrence, and are also the predominant cause of poor prognosis due to their intrinsic resistance to drugs and chemotherapy. Consequently, LSCs are a promising target for LUAD therapy. Noncoding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), exert many significant regulatory functions in the pathogenesis of human cancers, showing the necessity for a comprehensive understanding of the mechanisms that underlie lung carcinogenesis. Nonetheless, research on many known transcripts and messenger RNAs (mRNAs) has already generated new information. Unknown biomarkers in ncRNAs and systematic and comprehensive interrelation with unknown ncRNAs and mRNAs may provide further insights into the biology of LUAD. Herein, a set of novel ncRNAs that include miRNAs, lncRNAs, circRNAs, were identified and differentially expressed patterns of ncRNAs and mRNAs in LSCs and ALDH- H1975 LUAD tumor cells (LTCs) were obtained using stringent bioinformatics pipelines. Through a meta-analysis of the identified landscapes, novel competitive endogenous RNA (ceRNA) networks were constructed to reveal the potential molecular mechanisms that regulate the hallmarks of LSCs and LTCs. This study presents a summary of novel ncRNAs and the fundamental roles of differentially expressed ncRNAs implicated in the activity of LSCs and LTCs. In addition, the study also provides a comprehensive resource for the future identification of diagnostic, therapeutic, and prognostic biomarkers in LUAD.
REVIEW | doi:10.20944/preprints202207.0250.v1
Subject: Life Sciences, Virology Keywords: Emergence of Omicron and its mechanism; mutation and sub-lineages; Monoclonal antibodies; Antiviral drugs
Online: 18 July 2022 (07:48:00 CEST)
With the ongoing COVID pandemic, the emergence of a novel omicron variant in November 2021 has chaos the world. Despite mass vaccination, this omicron has spread rapidly raising concerns around the globe. The Omicron variant has a vast array of mutations as compared to another variant of concern with overall 50 mutations where 30 mutations are present in its spike protein. This mutation has led to immune escape and more transmissibility compared to other variants, including Delta. A cluster of mutations (H655Y, N679K, and P681H) present at the omicron spike protein could aid in transmission. Currently, no virus-specific data are available to predict the efficacy of anti-viral and mAbs drugs. However, two monoclonal antibody drugs: Sotrovimab and Evusheld are authorized for emergency use in COVID patients. This virus is not fading away soon. The easiest solution and less expensive measure to fight against this pandemic are following COVID appropriate protocols.There is need to strengthen the level of research for development of potential vaccines and anti-viral drugs. It is also important to monitor and expand genomic surveillance to keep track of the emergence of new variants thus avoiding the spread of new diseases worldwide. This article highlights the emergence of omicron and vast number of mutation in its protein. In addition, recent advancement in drugs approved by FDA to treat COVID patients has been listed and focused in this paper.
Subject: Biology, Anatomy & Morphology Keywords: adaptive significance; evolution of gall insects; gall-inducing insects; gall formation mechanism; insect effectors
Online: 24 August 2021 (13:04:19 CEST)
Galls are characteristic plant structures formed by cell size enlargement and/or cell proliferation induced by parasitic or pathogenic organisms. Insects are a major inducer of galls, and insect galls can occur on plant leaves, stems, floral buds, flowers, fruits, or roots. Many of these exhibit unique shapes, providing shelter and nutrients to insects. To form unique gall structures, gall-inducing insects are believed to secrete certain effector molecules and hijack host developmental programs. However, the molecular mechanisms of insect gall induction and development remain largely unknown due to the difficulties associated with the study of non-model plants in the wild. Recent advances in next-generation sequencing have allowed us to determine the biological processes in non-model organisms, including gall-inducing insects and their host plants. In this review, we first summarize the adaptive significance of galls for insects and plants. Thereafter, we summarize recent progress regarding the molecular aspects of insect gall formation.
Subject: Keywords: Tight sandstone; Low resistivity contrast oil pay; Reservoir Characteristic; Control mechanism; Longdong West area.
Online: 15 January 2021 (13:02:42 CET)
The log interpretation and evaluation of Chang 8 tight sandstone reservoir in Longdong West area, Ordos Basin, is facing great challenges due to the existence of low resistivity contrast oil pays. To better guide the exploration of oil resources in this area, the characteristics and control mechanism of low resistivity contrast oil pays were studied in this research. Firstly, according to the relative value of apparent resistivity increase rate of the target formation, the reservoir was divided into two types: low resistivity contrast oil pay (LRCP) and high resistivity oil pay (HRP). Then, the reservoir characteristics were studied by comparing and analyzing the experimental data, formation water data and logging data collected from the two reservoir types. On this basis, the control mechanism of LRCP was studied and summarized into reservoir micro factors and regional macro factors, respectively. It is found that the reservoir rock composition between LRCP and HRP is basically the same. Compared with HRP reservoir, the average porosity and permeability of LRCP reservoir are relatively better, but the pore structure is relatively poorer because of the high content of micro pores. When the filling pressure of crude oil is sufficient enough, the high oil saturation can be formed in LRCP reservoir. The high irreducible water saturation and high formation water salinity are the main micro factors reduced the reservoir resistivity. Besides, the difference of hydrocarbon expulsion capacity of source rock and the regional difference of formation water salinity are the macro factors influenced the distribution of LRCP and HRP from vertical and horizontal of the region. The formation of LRCP is controlled by the comprehensive influence of reservoir micro factors and regional macro factors. And the comprehensive consideration of the influence of micro factors and macro factors on LRCP is suggested during the log interpretation and evaluation.
ARTICLE | doi:10.20944/preprints201911.0224.v1
Subject: Materials Science, Metallurgy Keywords: Cu6Sn5 intermetallic; solid-state polymorphic transition; superstructure; transmission electron microscopy; damage mechanism; multiple reflows
Online: 19 November 2019 (04:05:13 CET)
The formation of high-melting-point Cu6Sn5 interconnections is crucial to overcome the collapse of Sn-based micro-bumps and produce reliable intermetallic interconnections in three-dimensional (3D) package. However, because of the multiple reflows in 3D package manufacturing, Cu6Sn5 interconnections will experience the cyclic polymorphic transitions in the solid state. The repeated and abrupt change in the Cu6Sn5 lattice due to the cyclic polymorphic transitions can cause extreme strain oscillations, producing damages at the surface and in the interior of the Cu6Sn5 matrix. Moreover, because of the polymorphic-transition-induced grain splitting and superstructure phase formation, the reliability of Cu6Sn5 interconnections will thus face great challenges in 3D package. In addition, the Cu6Sn5 polymorphic transition is structure-dependent, and the η′↔η polymorphic transition will occur at the surface while the η′↔ηs↔η polymorphic transition will occur in the deep matrix. Our results can provide in-depth understandings of structural evolution and damage mechanism of Cu6Sn5 interconnections in real 3D package manufacturing.
REVIEW | doi:10.20944/preprints201807.0008.v1
Subject: Life Sciences, Biophysics Keywords: antimicrobial peptides; cell-penetrating peptides; biophysical characterization; uptake mechanism; membrane disruption; peptide-lipid interactions
Online: 2 July 2018 (10:37:22 CEST)
In the last 20 years, an increasing number of studies have been reported on membrane active peptides, which exert their biological activity by interacting with the cell membrane either to disrupt it and lead to cell lysis or to translocate through it to deliver cargos into the cell and reach their target. These peptides are attractive alternatives to currently used pharmaceuticals. Antimicrobial peptides (AMPs) and peptides designed for drug and gene delivery currently in the drug pipeline suggest that these membrane active peptides will soon constitute a significant percentage of the drug market. Here, we focus on two most prominent classes of membrane active peptides; AMPs and cell-penetrating peptides (CPPs). AMPs are a group of membrane active peptides that disrupt the membrane integrity or inhibit the cellular functions of bacteria, virus and fungi. CPPs are another group of membrane active peptides that mainly function as cargo-carriers even though they may also show antimicrobial activity to some extent. Biophysical techniques to understand how they interact with the membrane have shed light on the peptide–membrane interaction at various levels of detail. Structural investigation of membrane active peptides in the presence of the membrane provides important clues on the effect of the membrane environment on peptide conformations. Advances in live imaging techniques have allowed examination of peptide action at a single cell or single molecule level. In addition to these experimental biophysical techniques, molecular dynamics simulations provided clues on the peptide-lipid interactions and dynamics of the cell entry process at atomic detail. In this review, we summarize the recent advances in experimental and computational investigation of membrane active peptides with particular emphasis on two amphipathic membrane active peptides, the AMP melittin and the CPP pVEC.
ARTICLE | doi:10.20944/preprints201804.0207.v1
Subject: Engineering, General Engineering Keywords: deep mining; coal seam floor; unloading disturbance; space–time difference; stress shell; mechanical mechanism
Online: 16 April 2018 (11:29:05 CEST)
Failure characteristics induced by unloading disturbance and the corresponding mechanical mechanism of the coal seam floor are important theoretical bases for water-bursting prevention from the floor of the coal seam and rock burst alarm in deep mining. However, the existing two-dimensional ground-pressure-control theory based on shallow mining cannot sufficiently guide deep-mining practices. In this study, the redistribution of mining-induced stress field in rocks surrounding the longwall face and mechanical behaviors of strata in deep mining are investigated through a combination of numerical simulation, physical simulation, and field measurement. Results demonstrate that mining-induced stress fields in the floor of the longwall face differ in space and time. Vertical stress unloading from top to bottom of the floor and horizontal stress unloading are relatively low. A concentration zone of high horizontal stress exists at stope boundaries. The critical yield load of rock stratum in the floor is determined through thin plate yield theory. Under the combined effect of concentrated high horizontal and vertical resilience stresses, strata in the floor fracture from seam to seam if the load increases to the minimum critical buckling value. Fractured strata slide along the fracture surface, which leads to floor heave. The stope floor shows evident time-delay progressive failure characteristics. The stress shell in the stope floor in deep mining is found to be a sensitive mechanical parameter that produces three-dimensional ground-pressure behavior in the floor. This ground-pressure behavior in the stope floor is controlled by the existence of the corresponding stress shell and effects induced by its space–time evolution. This study provides theoretical basis for the dynamic control of a hazard-inducing environment in engineering and minimizing or altering disaster-occurrence conditions during the construction engineering of the coal seam floor.
REVIEW | doi:10.20944/preprints201705.0212.v1
Subject: Biology, Physiology Keywords: cancer; cell-surface receptor; EGFR; molecular mechanism; phosphorylation; receptor tyrosine kinase; transmembrane signal transduction
Online: 30 May 2017 (08:34:04 CEST)
The epidermal growth factor receptor (EGFR) plays vital roles in cellular processes including cell proliferation, survival, motility and differentiation. Dysregulated activation of the receptor is often implicated in human cancers. EGFR is synthesized as a single-pass transmembrane protein, which consists of an extracellular ligand-binding domain and an intracellular kinase domain separated by a single transmembrane domain. The receptor is activated by a variety of polypeptide ligands such as epidermal growth factor and transforming growth factor α. It has long been thought that EGFR is activated by ligand-induced dimerization of the receptor monomer, which brings intracellular kinase domains into close proximity for trans-autophosphorylation. An increasing number of diverse studies, however, demonstrate that EGFR is present as a pre-formed, yet inactive, dimer prior to ligand binding. Furthermore, recent progress in structural studies has provided insight into conformational changes during the activation of a pre-formed EGFR dimer. Upon ligand binding to the extracellular domain of EGFR, its transmembrane domains rotate or twist parallel to the plane of the cell membrane, resulting in reorientation of the intracellular kinase domain dimer from a symmetric inactive configuration to an asymmetric active form (the “rotation model”). This model is also able to explain how oncogenic mutations activate the receptor in the absence of ligand without assuming that the mutations induce receptor dimerization. In this review, we discuss mechanisms underlying ligand-induced activation of the preformed EGFR dimer, as well as how oncogenic mutations constitutively activate the receptor dimer, based on the rotation model.
ARTICLE | doi:10.20944/preprints201704.0067.v1
Subject: Earth Sciences, Other Keywords: ice algae; brine channels; organic chemistry; Arctic sea ice; CICE model; mechanism development; biomacromolecules
Online: 12 April 2017 (05:12:28 CEST)
A numerical mechanism connecting ice algal ecodynamics with the buildup of organic macromolecules is tested within modeled pan-Arctic brine channels. The simulations take place offline in a reduced representation of sea ice geochemistry. Physical driver quantities derive from the global sea ice code CICE, including snow cover, thickness and internal temperature. The framework is averaged over ten boreal biogeographic zones. Computed nutrient-light-salt limited algal growth supports grazing, mortality and carbon flow. Vertical transport is diffusive but responds to pore structure. Simulated bottom layer chlorophyll maxima are reasonable, though delayed by about a month relative to observations due to uncertainties in snow variability. Upper level biota arise intermittently during flooding events. Macromolecular concentrations are tracked as proxy proteins, polysaccharides, lipids and refractory humics. The fresh biopolymers undergo succession and removal by bacteria. Baseline organics enter solely through cell disruption, so that the internal carbon content is initially biased low. By including exudation, agreement with dissolved organic or individual biopolymer data is achieved given strong release coupled to light intensity. Detrital carbon then reaches hundreds of micromolar, sufficient to support structural changes to the ice matrix.
ARTICLE | doi:10.20944/preprints201612.0104.v1
Subject: Engineering, Other Keywords: green logistics; negative externality of logistics; internalization of logistics negative external cost; incentive mechanism
Online: 20 December 2016 (10:37:21 CET)
The implementation of green logistics can reduce the increasingly serious environmental damage and improve the operating efficiency of logistics enterprises. In this paper, through quantitative calculation of logistics negative external costs, including traffic accidents, atmospheric pollution, noise pollution, and pollution caused by packaging, we build accounting standards to calculate the negative external cost of logistics enterprises that mainly generate pollution from transportation and packaging. Then, assuming the impetus provided by government implementing incentive mechanisms in a free market economy, we establish a ‘Logistics Negative External Cost Internalizing’ model, which quantitatively analyzes the relationships among freight rate, freight volume, investment of enterprise for implementing green logistics, and the subsidy given by government, under the comparison of the two modes ‘enterprise operates first’ and ‘government subsidizes first’. The results show that the introduction of ‘government subsidizes first’ incentive mechanism and increasing freight rate are helpful in promoting the process of logistics market greening.
ARTICLE | doi:10.20944/preprints202204.0103.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Monochoria angustifolia; Monochoria hastata; Flavonoid; Antioxidant mechanism; Natural populations; Phytochemical profile; Traditional herbal medicine; Phytopharmaceutical
Online: 12 April 2022 (04:08:17 CEST)
Plants of the genus Monochoria have long been utilized in food, cosmetics, and traditional herbal treatment. Thailand has the highest species diversity of this genus and a new member, Monochoria angustifolia (G. X. Wang) Boonkerd & Tungmunnithum has been recently described. This plant is called “Siam Violet Pearl” as a common name or “ไข่มุกสีม่วงแห่งสยาม” as its vernacular name in the same meaning in Thai language. Despite their importance, few researches on Monochoria species have been conducted. This study, thus, provided the results to fill in this gap by: i) determining flavonoids phytochemical profiles of 25 natural populations of M. angustifolia covering the whole floristic regions in Thailand, and ii) determining antioxidant activity using various antioxidant assays to investigate the probable mechanism. The results revealed that M. angustifolia presented a higher flavonoid content than the outgroup, M. hastata. Our results also revealed that flavonoids might be used to investigate Monochoria evolutionary connections and for botanical authentication. The various antioxidant assays revealed that M. angustifolia extracts preferentially act through a hydrogen atom transfer antioxidant mechanism. Pearson correlation analysis indicated significant correlations emphasizing that the antioxidant capacity is most probably the result of a complex phytochemical combinations rather than of a single molecule. Altogether, these results showed that this new species provide an attractive alternative starting material with phytochemical variety and antioxidant potential for the phytopharmaceutical industry.
REVIEW | doi:10.20944/preprints202203.0062.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: Major depression; inflammation; sickness behaviour; mechanism; model; microglia; zcitokynes; CRP; blood brain barrier; choroid plexus
Online: 3 March 2022 (10:28:08 CET)
Current lines of research into mood disorders indicate that immune mediators participating in the pathophysiology of chronic somatic disorders have potent influences on brain functions, even when these mediators are produced in peripheral tissues. Elevated levels of circulating immune molecules have been consistently associated with depressive symptoms in a number of clinical populations and experimental models, to the extent that major depressive disorder (MDD) is now seen, at least in part, as a disorder of immunity. This paradigm has brought to the fore the use of anti-inflammatory therapies as adjunctive to standard antidepressant therapy with the hope to improve treatment efficacy, particularly in those cohorts that do not respond well to standard medication. Such new practice requires the availability of biomarkers to tailor these new therapies to those most likely to benefit but also clear mechanisms of action describing the interaction between peripheral immunity and brain function. These mechanisms are generally studied in preclinical models that try to recapitulate the human disease through peripherally induced sickness behaviour as the model for immune-induced MDD. After an appraisal of the data in rodent models and their adherence to the data in clinical cohorts, we propose a modified model of periphery-brain interaction that goes beyond the currently established view of interaction between peripheral cytokines and microglia cells as the driver of depression. Instead, we suggest that brain barriers are primary actors in the communication between body and brain and, as a consequence, in the pathophysiology of the disease. This model suggests novel biomarkers, novel targets for therapies as well as a novel mechanism for resistance to standard treatments.
ARTICLE | doi:10.20944/preprints202104.0357.v1
Subject: Materials Science, Biomaterials Keywords: cavitation erosion; ion implanta; wear; failure analysis; cobalt alloy; stellite 6; damage mechanism; phase transformation
Online: 13 April 2021 (13:13:29 CEST)
From the wide range of engineering materials traditional Stellite 6 alloy exhibits excellent cavitation erosion (CE) resistance. In this work, the effect of nitrogen ion implantation of HIPed Stellite 6 on the improvement of CE resistance and both cobalt-rich matrix phase transformation due to nitrogen implantation and CE were stated. The CE resistance of stellites ion-implanted by 120 keV N+ ions two fluences: 5x1016 cm-2 and 1x1017 cm-2 were comparatively analysed with the unimplanted stellite and AISI 304 stainless steel. CE tests were conducted according to ASTM G32 with stationary specimen method. Erosion rate curves and mean depth of erosion confirm that the nitrogen implanted HIPed Stellite 6 two times exceeds the resistance to CE than unimplanted stellite, and has almost 10 times higher CE reference than stainless steel. The X-ray diffraction (XRD) confirms that HIPed Stellite 6 nitrogen ion implantation favours transformation of the ɛ(hcp) to γ(fcc) structure. Unimplanted stellite ɛ-rich matirx is less prone to plastic deformation than γ and consequently, increase of γ phase effectively holds carbides in cobalt matrix and prevents Cr7C3 debonding. This phenomenon elongates three times the CE incubation stage, slows erosion rate and mitigates the material loss. Metastable γ structure formed by ion implantation consumes the cavitation load for work-hardening and γ → ɛ martensitic transformation. In further CE stages, phases transform as for unimplanted alloy namely, the cavitation-inducted recovery process, removal of strain, dislocations resulting in increase of fcc phase. The CE mechanism was investigated using a surface profilometer, atomic force microscopy, SEM-EDS and XRD. HIPed Stellite 6 wear behaviour relies on the plastic deformation of cobalt matrix, starting at Cr7C3/matrix interfaces. Once the Cr7C3 losing their restrain, are debonding and removed. Carbides detachment creates cavitation pits which initiate cracks propagation through cobalt matrix, the loss of matrix phase and CE proceeds with a detachment of massive chunk of materials.
Subject: Social Sciences, Accounting Keywords: hierarchy; complexity; organization; formal authority; social mechanism; ideology; self-organization; responsibility; status; typology; literature review
Online: 11 February 2021 (12:53:32 CET)
The notion of hierarchy is a key characteristic of any complex system. This paper explores which notions of hierarchy are being used in the field of management and organization studies. Four distinct types of hierarchy are identified: a ladder of formal decision-making authority, a ladder of achieved status, a self-organized ladder of responsibility, and an ideology-based ladder. A social mechanism-based perspective serves to define and distinguish these four types. Subsequently, the typology is further developed by comparing the four hierarchy types in terms of their tacit/explicitness, (in)transitivity, and behavior- versus cognition-centeredness. This review article contributes to the literature by dissecting the general metaphor of hierarchy into four different constructs and their social mechanisms, which serves to create a typology of the various ways in which complex systems can be characterized as being hierarchical. This typology can inform future research drawing on any type of hierarchy.