ARTICLE | doi:10.20944/preprints202011.0506.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: sleep stage classification; ECG, nested–cycle sleep pattern; stage transition
Online: 19 November 2020 (11:10:07 CET)
：Sleep stage on the whole night is not steady. Sleepers generally pass through three to five cycles. In each cycle, there are occur four typical sleep stages, such as wake stage (WS), light stage (LS), deep sleep (DS), rapid eye movement sleep stage (REM). According to the natural routine, in this paper, we investigate the stage transition and analyze the feature of stage transition using the local cluster Algorithm (LCA). Two-cycle sleep model (TCSM) is proposed to automatically classify sleep stages using over-night continuous heart rate variability (HRV) data. The generated model is based on the characteristics of the nested cycle's sleep stage distribution and the transition probabilities of sleep stages. Experiments were conducted using a public data set including 400 healthy subjects (female 239, male 161) and the model’s classification accuracy was evaluated for four sleep stages: WS, LS, DS, REM. The experimental results showed that based on the TCSM model, the segmentation classification of pure sleep is 5.2% higher than that of the traditional method, and the accuracy of segmentation classification is 11.2% higher than the traditional sleep staging accuracy. The experimental performance is promising in terms of the accuracy, sensitivity, and specificity rates compared with the ones of the state-of-the-art methods. The study contributes to improve the quality of sleep monitoring in daily life using easy-to-wear HRV sensors.
ARTICLE | doi:10.20944/preprints202005.0319.v1
Subject: Mathematics & Computer Science, Probability And Statistics Keywords: COVID-19; structural break; growth stage
Online: 20 May 2020 (04:24:15 CEST)
COVID-19 is an infectious disease, growth of which depends upon the linked stages of the epidemic, the average number of people one person can infect and the time it takes for those people to become infectious themselves. We have studied the COVID-19 time series to understand the growth behaviour of COVID-19 cases series. A structural break occurs in the COVID-19 series at the change time form one stage to another. We have performed the structural break analysis of data available for 207 countries till April 20, 2020. There are 42 countries which have recorded five breaks in COVID cases series. This means that these countries are in the sixth stage of growth transmission and show a downward pattern in reporting in the daily cases, whereas countries with two and three breaks, record the rapid growth pattern in the daily cases. From this study, we conclude that the more the breaks in the series, there is more possibility to determine the constant or decreasing rate of daily cases. It is well fitted using lognormal distribution as this distribution is archived at its highest peak after some period and then suddenly it decreases at a longer time period. This can be seen in various countries like China, Australia, New Zealand and so on.
ARTICLE | doi:10.20944/preprints201807.0163.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: smoking; pathologic stage; pathologic grade; low risk
Online: 10 July 2018 (10:00:46 CEST)
Introduction: We investigated the potential effect of smoking on pathological staging in clinically low-risk patients. Material-Methods: Data of 59 patients who were diagnosed with a bladder tumor for the first time and had a single lesion radiologically and endoscopically smaller than 3 cm were investigated, retrospectively. A total of 33 patients who currently smoke or smoked were classified as ever smokers group and 26 patients who did not ever smoke were classified as never smokers group. Pathological diagnoses of the patients in both groups were compared. Results: A total of 9 patients (27.3%) in ever smokers group and 18 patients (69.2%) in never smokers group had Ta disease (p<0.05). Morover, 19 patients (57.6%) in ever smokers group and 5 patients (19.2%) in never smokers group had T1 disease (p<0.05). The number of patients with low grade (LG) tumor were 8 (24.2%) and 19 (73.1%) in ever smoking and never smoking groups, respectively (p<0.05). The number of patients with high grade (HG) tumor were 25 (75.8%) and 7 (26.9%) in ever smoking and never smoking groups, respectively (p<0.05). Ta HG was detected in 9 (27.3%) patients in ever smoking group. In contrast, no patients in never smoking group had Ta HG disease (p<0.05). The number of patients with T1 HG was 17 (51.5%) in ever smoking group and 2 (7.69%) in never smoking group (p<0.05). Conclusion:Smoking seems to associate with pathologically worse stage and grade in patients with primary, single, < 3cm bladder cancer.
ARTICLE | doi:10.20944/preprints201806.0115.v1
Online: 7 June 2018 (11:14:20 CEST)
The aim of this study was to determine the relationship between levels of leisure-time sports and physical activity and the stages of change in high school students with goal orientations. Methods: The sample consisted of 2168 students randomly selected to participate in a longitudinal study in Costa Rica (423), Mexico (408) and Spain (1337), with 1052 being boys, 1037 girls and 79 who did not specify sex, aged between 11 and 16 years old (M = 12.49, SD = .81). We used a questionnaire to ask students about their leisure-time sports and physical activity, about stages of change and to measure achievement goals. Results: The results show that students are more active in Costa Rica, most of them being in the stage of active change. Conclusions: We found significant differences in achievement goals in all three countries, which shows that students in active stages have higher values than those in the inactive stage.
ARTICLE | doi:10.20944/preprints201805.0320.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: smoking; pathologic stage; pathologic grade; low risk
Online: 23 May 2018 (08:48:03 CEST)
AbstractWe investigated the effect of cigarette smoking on pathological staging in clinically low-risk patients. Data of 59 patients who were diagnosed with bladder tumor for the first time and had a single lesion radiologically and endoscopically smaller than 3 cm were investigated retrospectively. 33 patients who smoked were classified as Group I, and 26 patients who did not smoke were classified as Group II. Pathological diagnoses of the patients in both groups were compared. The mean age of the patients were 64.8 (20–86) years. In Group II, 5 (19.2%) were female and 21 (80.8%) were male (p < 0.05). Nine patients (27.3%) in Group I and 18 patients (69.2%) in Group II had Ta disease (p < 0.05). Nineteen patients (57.6%) in Group I and 5 patients (19.2%) in Group II had T1 disease (p < 0.05). The number of patients with low grade (LG) tumor were 8 (24.2%) and 19 (73.1%) in Group I and in Group II, respectively (p < 0.05). The number of patients with high grade(HG) tumor were 25 (75.8%) and 7 (26.9%) in Group I and in Group II, respectively (p < 0.05). TaHG was detected in 9 (27.3%) patients in Group I. In contrast, no patients in Group II had TaHG disease (p < 0.05). The number of patients with T1HG was 17(51.5%) patients in Group I and 2 (7.69%) patients in Group II (p < 0.05). Smoking is associated with pathologically HG and stage in patients with first time bladder tumor which is single and smaller than 3 cm.
ARTICLE | doi:10.20944/preprints202210.0134.v1
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: endometriosis; endometrium; ErbB receptors; immunoprecipitation; implantation stage; infertility
Online: 11 October 2022 (03:30:29 CEST)
Several lines of evidence indicate that high proliferative bias in eutopic endometrium during secretory phase is a hallmark of endometriosis and that high occurrence of implantation failure in patients resulting in infertility is often associated with endometriosis. ErbB family of proteins, which regulate the proliferation capacity in mammalian cells, appear as potential group of proteins to cause higher proliferation and endometrial hostility to implantation process in endometriosis. However, we have no concrete knowledge regarding the involvement of ErbB family in human endometrium during the ‘implantation window’, i.e., days 20-24 of a typical ovulatory cycle in endometriosis associated infertility. In the present study, the cellular profiles of immunopositive ErbBs-1 to -4 in endometrium of endometriosis-free, infertile women (Group 1; n=11), and in eutopic endometrium of infertile women diagnosed with stage IV ovarian endometriosis (Group 2; n=13) during mid-secretory phase were examined and compared using standardized WERF EPHect guidelines. Computer-aided standardized combinative analysis of immunoprecipitation in different compartments revealed an overexpression of ErbB-1 in the epithelial, stromal and vascular compartments along with marginally higher ErbB-3 expressions (P< 0.06) in the vascular compartment and ErbB-4 expression (P< 0.05) in the glandular epithelium and stroma in endometrium during the window of implantation of women with primary infertility associated with stage IV ovarian endometriosis compared with disease-free endometrium from women. A global overexpression of ErbB-1 in the endometrium during implantation window may induce anomalous proliferative, inflammatory and angiogenic activities in it, which antagonizes endometrial preparation for embryo implantation.
ARTICLE | doi:10.20944/preprints202111.0415.v1
Subject: Engineering, Mechanical Engineering Keywords: Precision stage; Balanced platform; Balancing weight; Drive force offset; Yaw motion; Abbe er-ror; Error prediction; Low-cost stage; Open frame stage; Linear motion guide (LM Guide); Py-thon; GEKKO; ANSYS bushing joint
Online: 23 November 2021 (09:47:56 CET)
Recently, due to the miniaturization of electronic products, printed circuit boards (PCBs) have also become smaller. This trend has led to the need for high-precision electrical test equipment to check PCBs for disconnections and short circuits. The purpose of this study is to improve the position repeatability of the platform unit up to ±2.5 μm in a linear stage type test equipment. For this purpose, the causes of position errors of the platform unit are analyzed. The platform unit holding the PCB is driven by a single-axis linear ball screw drive system offset from its geometric center due to design constraints. The yaw rotation of the platform is found to have a dominant effect on position repeatability. To address this problem, the methods of adding balancing weights to the platform unit and adjusting the stiffness of LM Guides are proposed. This reduces the yaw rotation by moving the centers of mass and stiffness closer to the linear ball screw actuator. In the verification tests, the position repeatability was decreased to less than ±1.0 μm.
REVIEW | doi:10.20944/preprints202301.0192.v1
Subject: Life Sciences, Biotechnology Keywords: malaria vaccine, patents, stage of development.; transmission-blocking vaccines
Online: 11 January 2023 (03:08:51 CET)
Malaria is a parasitic infection that is a great public health concern and is responsible for high mortality rates worldwide. Different strategies have been employed to improve disease control, demonstrating the ineffectiveness of controlling vectors, and parasite resistance to antimalarial drugs requires the development of an effective preventive vaccine. There are countless challenges to the development of such a vaccine directly related to the parasite's complex life cycle. After more than four decades of basic research and clinical trials, the World Health Organization (WHO) has recommended the pre-erythrocytic Plasmodium falciparum (RTS, S) malaria vaccine for widespread use among children living in malaria-endemic areas. However, there is a consensus that major improvements are needed to develop a vaccine with a greater epidemiological impact in endemic areas. This review discusses novel strategies for malaria vaccine design taking the target stages within the parasite cycle into account. The design of the multi-component vaccine shows considerable potential, especially as it involves transmission-blocking vaccines (TBVs) that eliminate the parasite's replication towards sporozoite stage parasites during a blood meal of female anopheline mosquitoes. Significant improvements have been made but additional efforts to achieve an efficient vaccine are required to improve control measures. Different strategies have been employed, thus demonstrating the ineffectiveness in controlling vectors, and parasite resistance to antimalarial drugs requires the development of a preventive vaccine. Despite having a vaccine in an advanced stage of development, such as the RTS, S malaria vaccine, the search for an effective vaccine against malaria is far from over. This review discusses novel strategies for malaria vaccine design taking into account the target stages within the parasite’s life cycle.
ARTICLE | doi:10.20944/preprints202208.0064.v1
Subject: Earth Sciences, Palaeontology Keywords: Abadiella; South China; Gondwana; stratigraphic correlation; Cambrian Stage 3
Online: 2 August 2022 (11:13:00 CEST)
The taxonomy of trilobites Abadiella Hupé, 1953 and Parabadiella Zhang, 1966 from the lower Cambrian of Gondwana has long been a controversy. Based on newly-collected and formerly-reported materials, 94 trilobite cranidia within 21 species are selected for morphometric analyses: principal components analysis (PCA) and canonical variates analysis (CVA). The integrated morphological characters are successfully accounted for by two principal components in PCA. The further validations for the presupposed qualitative groupings are indispensable to detect and calibrate the ultimate taxonomic results in CVA. By this way, all specimens distributed in a consistent morphospace in PCA and the short distances between them demonstrate their close morphological affinity, supporting their congeneric status within Abadiella. Additionally, three morphotypes were recognized from all selected specimens and they were eventually revised and incorporated into A. bourgini Hupé, 1953, A. huoi Zhang, 1966, and A. yunnanensis Luo, 1981, through stepwise test-calibration to get a high correct rate as far as possible in CVA. From this, it is certain that A. huoi is conspecific in South Australia and South China. Its occurrence allows to correlate the Australian A. huoi Range Zone to the identical zone in South China (in platform), having an approximately consistent stratigraphic range in the two regions. In comparison with A. huoi, A. bourgini was reported from fewer localities in South China. Nevertheless, its presence in the Daguinaspis Zone of Issendalenian Stage in Morocco permits a correlation with Chinese and Australian A. huoi Zone. As an auxiliary marker for A. huoi, the occurrence of A. bourgini in Morocco, South Australia and South China reinforce the correlation potential and resolution in species-level for the Cambrian Stage 3 in Gondwana region.
REVIEW | doi:10.20944/preprints202207.0140.v1
Subject: Medicine & Pharmacology, Other Keywords: breast cancer; stage-wise costs; direct medical costs; modeling
Online: 8 July 2022 (10:50:29 CEST)
Breast cancer (BC) is a heterogeneous disease representing a substantial economic burden. In order to develop policies that successfully decrease this burden, the factors affecting costs need to be fully understood. Evidence suggests that early detection in Stage I has a lower cost than late detection. We aim to provide conservative estimates of BC's stage-wise medical costs from German healthcare and the payer's perspective. To this end, we conducted a literature review of articles evaluating stage-wise costs of BC in Germany through PubMed, Web of Science, and Econ Lit databases supplemented by Google Scholar. We developed a decision tree model to estimate BC related medical costs in Germany using available treatment and cost information. The review generated seven studies; none estimated the stage-wise costs of BC. The studies were classified into two groups: (1) case scenarios (five studies) and two studies based on administrative data. The first sickness funds data study (Gruber, Stock, et al. 2012) used 1999 information to approach BC attributable cost; their results suggest a range between €3,929 and €11,787 depending on age. The second study (Kreis, Plöthner, et al. 2020) used 2011-2014 data and suggested an initial phase incremental cost of €21,499, an intermediate phase cost of €2,620, and a terminal phase cost of €34,513 per incident case. Our decision tree model based BC stage-wise cost estimates were €21,523 for Stage I, €25,679 for Stage II, €30,156 for Stage III, €42,086 for Stage IV. Alternatively, the modeled cost estimates are €20,284 for the initial phase of care, €851 for the intermediate phase of care, and €34,963 for the terminal phase of care. Our estimates for phases of care are consistent with recent German estimates provided by Kreis and Plöthner et al. Furthermore, the data collected by sickness funds are collected primarily for reimbursement purposes, where the German ICD-10 classification system defines a cancer diagnosis. As a result, claims data lack the clinical information necessary to understand stage-wise BC costs. Our model-based estimates fill the gap and inform future economic evaluations of BC interventions.
ARTICLE | doi:10.20944/preprints202107.0170.v1
Subject: Earth Sciences, Atmospheric Science Keywords: Marine Isotope Stage 3; sea level; tectonics; GIA; Calabria
Online: 7 July 2021 (08:42:48 CEST)
Investigation of sea-level positions during the highly-dynamic Marine Isotope Stage 3 (MIS 3: 29-61 kyrs BP) proves difficult because: i) in stable and subsiding areas, coeval coastal sediments are currently submerged at depths of few to several tens of meters below present sea level; ii) in uplifting areas, the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at depth of -130 m, followed by marine transgression that determined the development of ravinement surfaces. This study discusses previous research in the Mediterranean and elsewhere, and describes new fossiliferous marine deposits laying on metamorphic bedrock of Cannitello (Calabria, Italy). Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these deposits, presently between 28 and 30 meters above sea level, formed during MIS 3.1. Elevation correction of the Cannitello outcrops (considered in an intermediate-to-far-field position with respect to the ice sheet) with the local vertical tectonic rate and Glacial Isostatic Adjustment (GIA) rate allows to propose a revision of the eustatic depth for this highstand. Our results are consistent with recently proposed estimates based on a novel ice sheet modelling technique.
REVIEW | doi:10.20944/preprints202104.0720.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: High Gain, Single Stage, Switched Inductor Buck Boost Converter
Online: 27 April 2021 (12:51:21 CEST)
In this research paper, a high gain transformer less inverter modeling which is used for the smart grid technology or as the stand alone for home appliances is proposed. The proposed transformer less topology provides a higher voltage gain, low cost, small size and simple control stand alone transformer less inverter for home appliances. The above inverter is modeled by using software which is known as MATLAB/ Simulimk.
REVIEW | doi:10.20944/preprints202101.0340.v1
Subject: Biology, Anatomy & Morphology Keywords: functional connectivity; structural connectivity; multihabitat; barrier; nursery; life stage
Online: 18 January 2021 (13:49:20 CET)
Many marine species use different habitats at different stages of their life cycle. Functional connectivity, the degree to which the seascape facilitates or impedes movement between habitat patches, is poorly studied in marine systems. We reviewed the scientific literature to explore the various barriers preventing functional connectivity between marine habitats and how the removal of these barriers may restore connectivity. To our knowledge, this is the first systematic review to investigate functional connectivity between life cycle habitats for a range of marine species. A total of 4,499 records were identified and screened, leaving 69 publications eligible for review. The results highlighted a range of distances between nursery and adult habitats that limited functional connectivity for a number of species, predominantly reef fishes. For some species, adults were absent on reefs >9km from the closest nursery habitat, suggesting a threshold for connectivity. Similarly, increased distance between spawning and settlement habitats decreased settling success of larvae of various taxa. Pelagic larval duration, seascape topography and climate change were also shown to impact functional connectivity during the larval phase. The removal and mitigation of barriers preventing functional connectivity, including dams and habitat fragmentation, restored connectivity between disconnected life cycle habitats, but the efficacy of these approaches differed between species and studies. The results of this review deepen our understanding of marine functional connectivity between life cycle habitats via larval, juvenile, and adult dispersal. These findings have implications for the design and management of marine reserve networks.
REVIEW | doi:10.20944/preprints202004.0361.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: COVID-19; pandemic; asymptomaticspread; early-stage COVID-19 mitigation
Online: 20 April 2020 (06:18:33 CEST)
Background: Early-stage interventions in a potential pandemic are important tounderstand as they can make the difference between runaway exponential growththat is hard to turn back and stopping the spread before it gets that far. COVID-19 is an interesting case study because there have been very different outcomesin different localities. These variations are best studied after the fact if precisionis the goal; while a pandemic is still unfolding less precise analysis is of value inattempting to guide localities in the early stages to learn lessons of those that pre-ceded them. Methods: I examine three factors that could differentiate strategy: asymptomaticspread, differences in use of the Bacillus Calmette-Guerin (BCG) tuberculosis vac-cine and cloth face masks.Results:Differences in disease progression as well as the possibility of alternativestrategies to prevent COVID-19 from entering the runaway phase or damping itdown later can be elucidated by a study of asymptomatic infection. A study todemonstrate not only what fraction are asymptomatic but how contagious they arewill also inform policy on universal mask wearing. Conclusions: While a COVID-19 outbreak is at a level that makes accurate trace-and test possible, investigation of asymptomatic transmission is viable and shouldbe attempted to enhance understanding of spread and variability in the disease aswell as policy options for slowing the spread.
ARTICLE | doi:10.20944/preprints201705.0215.v1
Subject: Biology, Ecology Keywords: downed deadwood; decay stage; decomposition; wood density; wood moisture
Online: 30 May 2017 (09:04:25 CEST)
Deadwood represents a source of nutrients, carbon and water for metabolism within forest ecosystem. Nutrients are mobilized due to the decomposition of wood, which is a long-term process that can be best studied by analysing environmental data on a temporary scale. Our study provides physico-temporal data on the downed logs of three major tree species in European temperate forests: Abies alba Mill., Fagus sylvatica L. and Picea abies (L.) Karst. Time since death was obtained using tree censuses (repeated for 40 years) and dendrochronology for each single downed log, the oldest being 75 years old. Standard laboratory methods were used for the determination of wood density and moisture changes. F. sylvatica was decomposed rapidly in the initial phase – mass loss was 50% during the 5 years after death, while A. alba and P. abies lost 13% and 16%, respectively. Downed logs of F. sylvatica contained 391 kg of water per m3, while these of P. abies 279 kg. A log-transformed linear model was created that shows the dependence of time since death on mass loss. According to the model, F. sylvatica had the shortest total decomposition time (39 years), followed by A. alba (58 years) and P. abies (86 years).
ARTICLE | doi:10.20944/preprints202301.0107.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: cost analysis; early stage; health economics; lung cancer; screening programme.
Online: 5 January 2023 (11:30:30 CET)
BACKGROUND: The National Lung Screening Trial (ILST) and the NELSON study showed that lung cancer-specific mortality can be reduced by 20-24% using low-dose computed tomography (LDCT) screening in high-risk populations, due to an increase in early-stage diagnoses. RESEARCH QUESTION: How much lung cancer-related direct costs may be reduced using a LDCT screening programme based on the ILST protocol in a public healthcare system?STUDY DESIGN AND METHODS: Cost analysis of lung cancer screening (LCS) vs. usual care in the framework of the retail price of the Catalan public healthcare system. The LCS group included costs of screening (ILST protocol), treatment cost according to weighted average distribution of TNM staging in the NLST and NELSON trials, lung cancer detection rate (CDR) and smoking cessation intervention. The usual care group included treatment costs based on distribution of TNM staging registered in the Spanish index hospital. RESULTS: In the usual care group, treatment costs were €91,959. In the 5-year duration of the LCS programme, the average expected costs per subject were €1,342 (range €1,054-1,832 depending on malignancy in detected nodules) for screening and €32,431 for treatment, with an expected reduction of €952 based on an average CDR of 1.6%. The decrease in cost resulting from stage shift offsets 70.6% of the costs of the screening programme. INTERPRETATION: Baseline 5-year LCS costs are low according to the ILST protocol. In the Catalan public healthcare system, the expense reduction from the stage shift due to the LCS programme compensates a substantial part of its costs.
ARTICLE | doi:10.20944/preprints202201.0291.v1
Subject: Medicine & Pharmacology, Nursing & Health Studies Keywords: end-stage renal disease; peritoneal dialysis; far-infrared therapy (FIR)
Online: 20 January 2022 (09:05:44 CET)
Introduction: The treatment of peritoneal dialysis in end-stage renal disease is increasing in clinical practice. The main purpose of this study was to evaluate the effect of far-infrared radiation therapy on inflammation and the cellular immunity of patients undergoing peritoneal dialysis. Materials and Methods: We recruited 56 patients undergoing peritoneal dialysis, and we included 32 patients from the experimental group and 24 patients from the control group in the final analysis. The experimental evaluation in our study was as follows: (1) We used abdominal computed tomography to measure the diameter and degree of hardening of the abdominal veins and large blood vessels to explore the changes in abdominal blood vessels. (2) The study compared the effects of peritoneal dialysis using albumin, blood urea nitrogen, creatinine, white blood cell, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, erythrocyte sedimentation rate, Hs-CRP clearance rate, and HBAlC. (3) We compared the cytokine concentration of blood between the two groups while controlling for GM-CSF, IL-2, IFN-γ, IL-6, IL-18, IL-4, IL-5, IL-13, IL-12p70, TNF-α, and IL-1β. Results and Discussion: (1) There was no significant difference in the abdominal blood vessels of the experimental group relative to the control group according to abdominal CT measured over 6 months. (2) Our study demonstrates the statistically significant effect of FIR therapy on the following parameters: albumin (p = 0.048*), creatinine (p = 0.039*), and Hs-CRP (p < 0.001**) decreased significantly, and glomerular filtration rate (eGFR, p = 0.043*) and glucose (p < 0.001**) increased significantly. Our study found that, in the experimental group, albumin and creatinine decreased significantly due to FIR therapy for 6 months. However, our study also found that, in the experimental group, glucose (p < 0.001**) increased significantly due to FIR therapy for 6 months. Peritoneal dialysis combined with FIR can reduce the side effects of glucose in dialysis buffer, which interferes with peritoneal inflammation and peritoneal mesothelial cell fibrosis. In addition, we also found that, in the experimental group, Hs-CRP (p < 0.001**) decreased significantly due to FIR therapy for 6 months. (3) No statistical significance in the inflammatory cytokines related to FIR therapy differences was observed in our study. IFN-γ (p = 0.124), IL-12p70 (p = 0.093), IL-18 (p = 0.213), and TNF-α (p = 0.254) did not exhibit significant improvements in peritoneal dialysis with FIR treatment over 6 months. IFN-γ and IL-18 in the plasma of patients in the experimental group and the control group were higher in the third month than in the first month. Conclusion: We found that the effect of peritoneal dialysis improved significantly with FIR therapy, and significant improvements in the peritoneal permeability and inflammatory response were observed. end-stage renal disease; peritoneal dialysis; far-infrared therapy (FIR)
ARTICLE | doi:10.20944/preprints201912.0213.v1
Subject: Medicine & Pharmacology, Other Keywords: short stature; type 2 diabetes; end-stage renal disease; mortality
Online: 16 December 2019 (11:12:15 CET)
Short stature has been associated with increased various disease and all-cause death, but no reliable data exist the association between height and end-stage renal disease (ESRD) in diabetic patients. We investigated the relationship between short stature, development of ESRD, and mortality in type 2 diabetes. This study analyzed clinical data using the National Health Insurance Database in Korea. Height was stratified by five groups according to age and sex. Risk of ESRD and all-cause mortality was analyzed with Cox proportional hazards models. During a 6.9-year follow-up period, 220,457 subjects (8.4%) died and 28,704 subjects (1.1%) started dialysis. Short stature significantly increased the incidence of ESRD and all-cause mortality in the overall cohort analysis. In multivariable analysis, hazard ratios (HR) for development of ESRD comparing the highest versus lowest quartiles of adult height were 0.86 (95% confidence interval (CI), 0.83–0.89). All-cause mortality also decreased with highest height compared to patients with lowest height after fully adjusting for confounding variables (HR 0.79, 95% CI, 0.78–0.81). Adult height had an inverse relationship with newly diagnosed ESRD and all-cause in both males and females. Short stature is strongly associated with an increased risk of ESRD and all-cause mortality in type 2 diabetes.
ARTICLE | doi:10.20944/preprints201806.0378.v1
Subject: Physical Sciences, Astronomy & Astrophysics Keywords: stellar evolution; late stage stellar evolution; binarity; transients; planetary nebulae
Online: 25 June 2018 (10:30:21 CEST)
Intermediate-luminosity-optical-transients (ILOTs) are stellar outbursts with luminosity between those of classical novae and supernovae. They are divided into a number of sub-groups depending on the erupting progenitor and the properties of the eruption. Many of the ILOTs sit on the slanted Optical Transient Stripe (OTS) in the Energy-Time Diagram (ETD) that shows their total energy vs. duration of their eruption. We describe the different kinds of ILOTs that populate the OTS and other parts of the ETD. We also stand on similarities between Planetary Nebulae (PN) to ILOTs, and suggest that some PNe were formed in an ILOT event. The high energy part of the OTS is reserved to the supernova impostors -- giant eruption of very massive stars. We show results of 3D hydrodynamical simulations of supernova impostors that expose the mechanism behind these giant eruptions, and present new models for recent ILOTs. We stand on the connection between different kinds of ILOTs, and suggest that they are powered by a similar source of energy -- gravitational energy released by mass transfer.
ARTICLE | doi:10.20944/preprints201710.0031.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Breast milk; Carotenoids; Tocopherols; Colostrum; Lactation stage; Cross-sectional study
Online: 6 October 2017 (08:39:21 CEST)
This study aims to quantify carotenoids and tocopherols in human milk from healthy Chinese women, and to explore their associations with region, lactation stage, and maternal socio-economic and obstetric factors. Human milk was obtained from 509 healthy mothers and the compounds of carotenoids and tocopherols were analyzed by high-performance liquid chromatography after mild saponification and solvent extraction. Socio-economic and obstetric characteristics of the mothers and their dietary intakes through a single 24-hour dietary recall were evaluated. The median content of each component [μg/100mL, median (interquartile range)] in colostrum and mature milk was, respectively, β-carotene 8.0 (4.7-15.2) and 1.8 (1.4-2.7), β-cryptoxanthin 6.2 (2.4-12.9) and 1.8 (1.1-3.4), lutein 5.7 (2.9-10.2) and 3.4 (1.5-6.0), lycopene 6.3 (4.0-9.9) and 1.4 (1.1-2.0), zeaxanthin 1.0 (0.6-1.5) and 1.0 (0.6-1.4), α-tocopherol 645 (388-1176) and 211 (131-321), γ-tocopherol 68 (48-121) and 77 (45-120). The levels of all those vitamins presented regional differences, and decreased as lactation stage increased except for zeaxanthin and γ-tocopherol. Associations of carotenoid contents with maternal education, delivery mode, and present body mass index were found in multivariate analyses. These results suggest that some region, lactation stage, obstetric and socio-economic factors are associated with human milk concentrations of carotenoids and tocopherols in healthy Chinese mothers.
ARTICLE | doi:10.20944/preprints201610.0079.v1
Subject: Engineering, Civil Engineering Keywords: river confluence; stage-discharge relationship; hydrodynamic influence; backwater; flow separation
Online: 19 October 2016 (12:31:32 CEST)
An accurate assessment of the stage-discharge relationship in open channel flows is necessary and important to the design and management of hydraulic structures and engineering in practical hydrosystems such as rivers and streams. While the flow structures and patterns at open channel junctions are interesting and have been widely studied in the literature, this paper focuses further on the effect of flow junctions on stage-discharge relationship at mountain river confluences. In this study, both the flume and physical model experiments are designed and performed carefully to test and analyze the complex flow structures and characteristics at river confluences with different configurations and hydraulic conditions. The impacts of the flow junctions on the traditional stage-discharge relationship are analyzed in this study. The results of this study are discussed in the paper for the understanding of flow structures at flow junctions and the design and management of hydraulic structures in river engineering.
ARTICLE | doi:10.20944/preprints202207.0354.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: multi-stage double-suction centrifugal pump; non-hierarchical RSM; MIGA; optimization
Online: 25 July 2022 (07:33:26 CEST)
In order to improve the operation performance of the multi-stage double-suction centrifugal pump and reduce the internal energy loss of the pump, this paper proposes a single-objective optimization design method based on non-hierarchical response surface model (RSM) and the multi-island genetic algorithm (MIGA). Nine parameters, such as the blade outlet width and blade wrap angle, were used as design variables, and the optimization objective was the efficiency under design conditions. In total, 149 sets of valid data were obtained under the latin hypercube sampling method (LHS), the corresponding thresholds were set for efficiency and head, and 99 sets of valid data were obtained. A cross-validation analysis of the sieved data was carried out based on non-hierarchical RSM, global optimization of the efficiency was carried out using MIGA, and numerical verification was carried out via CFD. The research results show that compared with hierarchical RSM, non-hierarchical RSM can approximate the nonlinear relationship between the objective function and the design variables with higher accuracy, and the model fitting R2 value was 0.919. The efficiency was improved by 3.717% after optimization. The overall prewhirl of the impeller inlet after optimization decreased, the internal speed of the volute significantly improved, the large-area vortex at the volute and the outlet pipe was eliminated, the impact loss at the volute separating tongue disappeared, and the overall hydraulic performance of the pump was improved. The total entropy output value of the optimized pump was reduced by 4.79 (W/K), mainly concentrated in the reduction in the entropy output value of the double volute, and the overall energy dissipation of the pump was reduced.
ARTICLE | doi:10.20944/preprints202105.0190.v2
Subject: Life Sciences, Biochemistry Keywords: Parkinson’s disease; neurotoxic model; early stage; biologically active substances from insects
Online: 14 May 2021 (10:58:45 CEST)
The effect of aqueous extracts of the biomass of the adult Ulomoides dermestoides beetle on the delayed effects of the defoliant paraquat causing parkinsonism in experimental mice was evaluated. The motor activity of the animals was analyzed in behavioral tests using a rotarod and a vertical pole. The number of tyrosine hydroxylase-immunopositive neurons in the ventral part of the substantia nigra of the midbrains of experimental and control mice was studied by immunohistochemistry. In the model in vitro system with SH-SY5Y human neuroblastoma, the effect of the extracts on cell proliferation was examined in the absence and presence of the neurotoxin MPP+. The isolation of biologically active substances from raw biomass using cavitation effects made it possible to obtain extracts with protective properties in the model of an early stage of Parkinson's disease used in this study.
ARTICLE | doi:10.20944/preprints202001.0272.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: Exergame; depression; hemodialysis; end-stage renal disease; wearable technology; digital health
Online: 23 January 2020 (16:29:53 CET)
Regular exercise can reduce depression. However, the uptake of exercise is limited in patients with end-stage renal disease undergoing hemodialysis. To address the gap, we designed a gamified non-weight-bearing exercise program (Exergame), which can be executed during hemodialysis treatment. The Exergame is virtually supervised based on its interactive feedback via wearable sensors attached on lower extremities. We examined the effectiveness of this program to reduce depression symptom compared to supervised exercise in 73 hemodialysis patients (age=64.5±8.7years, BMI=31.6±7.6kg/m2). Participants were randomized into an Exergame group (EG) or a Supervised-exercise group (SG). Both groups received similar exercise tasks for 4-week, 3-session per week, 30-min per session, during hemodialysis treatment. Depression symptom was assessed at baseline and 4-week using Center for Epidemiologic Studies Depression (CES-D). Both groups showed significant reduction in depression score (37%, p<0.001, Cohen’s effect size d=0.69 in EG vs. 41%, p<0.001, d=0.65 in SG) with no between-group difference for the observed effect (p>0.050). The EG expressed a positive exercise experience including fun, safety, and helpfulness of sensor-feedback. Together, results suggested that the virtually-supervised low-intensity Exergame is feasible during routine hemodialysis treatment. It is as effective as supervised-exercise to reduce depression symptom, while reducing burden of administrating exercise in dialysis clinics.
ARTICLE | doi:10.20944/preprints201806.0230.v1
Subject: Social Sciences, Education Studies Keywords: interdisciplinary communication; early architectural design stage; procedural information; generative modeling; dashboard
Online: 14 June 2018 (10:33:18 CEST)
The purpose of interdisciplinary communication during the early architectural design stage is to achieve the early integration of knowledge in different professional fields, which can help architects to choose correct design development strategies during the early architectural design stage. However, because there is too little information at the early design stage, and design solutions are still rapidly changing and developing, the uncertainties at this stage make it difficult for consultants in other disciplines to provide their views and analysis. In spite of this situation, the emergence of generative modeling is changing design procedures and methods of communication and cooperation for architectural teams, and has brought about a shift in the way architects transmit design information from "what" (declarative information) to "how" (procedural information). Generative modeling is like an aircraft's dashboard: It can provide a basis for interdisciplinary communication, provide interdisciplinary knowledge packages, and bring about a shift in interdisciplinary communication that will reduce the architectural team's communication needs and cost. This study uses a real design case to show the feasibility of generative modeling. Employing generative modeling as a basis, architects can enhance the efficiency of design change and multi-disciplinary communication during the early design stage, integrate specialized knowledge in relevant fields, use this knowledge to formulate design criteria for the next stage, and effectively transmit design decisions. As a consequence, the changes to the cost structure of design revisions and communication between different disciplines has initiated a paradigm shift toward multi-disciplinary communication in architectural design.
ARTICLE | doi:10.20944/preprints202209.0452.v1
Subject: Engineering, Civil Engineering Keywords: Flooding from Groundwater; FEFLOW; Groundwater Modelling; Rise in River stage, Super Mesh
Online: 29 September 2022 (05:53:43 CEST)
Groundwater (GW) flooding mechanisms differ from river flooding both spatially and temporally, and preventative methods against groundwater flooding must take this into account. Although groundwater flooding caused by river water rise occurs seldom, it can occasionally become severe and last for a long time if the river is significantly flooded. In the southwest portion of the research domain, Friedrichshafen with a few urban communities, the level of the groundwater table was discovered to be roughly 1 m below the surface. It was discovered that the urban settlement area only has one-story buildings. In the study region, it is typical for the single-story building's foundation bottom level to extend up to a depth of about 1.5 meters. Therefore, flood mitigation methods are taken into account for the southwest portion of the study region. The installation of a pumping well, drainage, and a barrier in the affected area are three different flood control strategies that are taken into consideration for the study area. From a technical and cost-benefit perspective, installing a pumping well that withdraws water and lowers the groundwater table was found to be the most effective flood control measure locally in a small region (e.g., 1km x 1km). By contrast, removing groundwater by building drainage and barriers was also shown to be ineffective to lower the groundwater table over an extended region and was significantly more expensive than the installation of wells. Additionally, when river flooding is taken into account compared to the default scenario where no intake of water from the river is included along the western border of the study area, it is discovered that the spread of pollution is significantly greater.
ARTICLE | doi:10.20944/preprints202202.0237.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Membranous glomerulonephritis; remission; nephrotic syndrome; chronic kidney disease; end-stage kidney diseases
Online: 18 February 2022 (14:49:32 CET)
Background: Membranous glomerulonephritis (MGN) is one of the most common causes of nephrotic syndrome in non-diabetic adults, accounting for up to one-third of biopsy diagnostics in some regions. A watchful waiting strategy has been adopted to accurately assess the success of MGN. In this study, we predict prognostic risk factors for primary MGN patients for effective intervention and prognosis. Materials and Methods: This is a retrospective study design involving 125 biopsy-proven MGN subjects on follow-up from January 2012 to October 2019 in Hospital Serdang and Hospital Kuala Lumpur, Malaysia. Result and Conclusion: After the median follow-up of 36 (15.0-57.0) months, 26 (20.8%) consisting of 17 (13.6%) primary MGN and 9 (7.2%) secondary MGN subjects achieved complete remission while 17 (13.6%) and 10 (8.0%) of primary and secondary MGN subjects respectively achieved spontaneous remission. Subjects with nephrotic range proteinuria have 2.917 odds more at risk of primary MGN while subjects with hypertension have 2.417 odds risk of primary MGN compared to those with no hypertension at presentation. Multiple logistic regression models retained only factors directly associated with MGN with only nephrotic range proteinuria associated with primary MGN. Those with nephrotic range proteinuria were 3.04 times the odds of primary MGN when compared with those without nephrotic syndrome (95% C. I = 1.089, 8.472). The nephrotic syndrome could be used to determine the prognosis in patients with primary MGN especially those at risk of end-stage kidney disease.
ARTICLE | doi:10.20944/preprints202108.0109.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Membranous glomerulonephritis (MGN); Retinol binding protein (RBP); Prognostication; End-stage renal diseases
Online: 4 August 2021 (12:06:22 CEST)
Initially, retinol-binding protein (RBP), was thought to be a biomarker for proximal convoluted tubule dysfunction could be important in chronic kidney diseases (CKD). Membranous glomerulonephritis (MGN) is an important cause of CKD and end-stage renal disease (ESRD). Therefore, monitoring MGN patients using urinary RBP is important in effective treatment decision making and prognostication of MGN patients. Enzyme-linked immunosorbent assay (ELISA) technique was used to detect the RBP in the urine samples of 69 MGN patients comprising 47 primary and 22 secondary MGN, at the end of the follow-up period. The test for the urinary biomarker gave the following results: urinary RBP was detected in 27 (39.1%) and 6 (8.7%) of the primary and secondary MGN patients, respectively. The correlation analysis demonstrated a significant relationship between urinary RBP and renal function test parameters, in addition to a logistic regression analysis that proved urinary RBP as a prognostic non-invasive biomarker for primary MGN. Therefore, urinary RBP could be employed to monitor and provide effective prognosis and early treatment decisions in primary MGN.
ARTICLE | doi:10.20944/preprints202105.0460.v1
Subject: Biology, Anatomy & Morphology Keywords: Bacteria; community composition; growth stage; rhizosphere; root nodule; soybean; 16S rRNA gene
Online: 20 May 2021 (09:13:15 CEST)
Bacterial communities in rhizosphere and root nodules have significant contributions to the growth and productivity of the soybean (Glycine max L.). In this report, we analyzed the physiological properties and dynamics of bacterial community structure in rhizosphere and root nodules at different growth stages using BioLog EcoPlate and high-throughput sequencing technology, respectively. The BioLog assay found that the metabolic capability of rhizosphere is in increasing trend in the growth of soybeans as compared to the bulk soil. As a result of the Illumina sequencing analysis, the microbial community structure of rhizosphere and root nodules was found to be influenced by the variety and growth stage of the soybean. At the phylum level, Actinobacteria were the most abundant in rhizosphere at all growth stages, followed by Alphaproteobacteria and Acidobacteria and the phylum Bacteroidetes showed the greatest change. But, in the root nodules Alphaproteobacteria were dominant. The results of the OTU analysis exhibited the dominance of Bradyrhizobium during the entire stage of growth, but the ratio of non-rhizobial bacteria showed an increasing trend as the soybean growth progressed. These findings revealed that bacterial community in the rhizosphere and root nodules changed according to both the variety and growth stages of soybean in the field.
REVIEW | doi:10.20944/preprints202105.0054.v1
Subject: Biology, Anatomy & Morphology Keywords: Anopheles mosquito; Body size; Fecundity; Gonotrophic cycle; Immature stage; Insecticide; Longevity; Temperature
Online: 5 May 2021 (12:41:25 CEST)
The rearing temperature of the immature stages can have a significant impact on the life-history traits and the ability of adult mosquitoes to transmit diseases. This review assessed published evidence of the effects of temperature on the immature stages, life-history traits, insecticide susceptibility, and expression of enzymes in the adult Anopheles mosquito. Original articles published through 31 March 2021 were systematically retrieved from Scopus, Google Scholar, Science Direct, PubMed, ProQuest and Web of Science databases. After applying eligibility criteria, 29 studies were included. The review revealed that immature stages of Anopheles arabiensis were more tolerant (in terms of survival) to a higher temperature than An. funestus and An. quadriannulatus. Higher temperatures resulted in smaller larval size and decreased hatching and pupation time. The development rate and survival of Anopheles stephensi were significantly reduced at a higher temperature than a lower temperature. Increasing temperatures decreased the longevity, body size, length of the gonotrophic cycle and fecundity of Anopheles mosquitoes. Anopheles mosquitoes exposed at 18° or 30 °C had a higher risk of dying compared to those exposed at 25 °C. Increasing temperature also significantly increased NOS expression and decreased insecticide toxicity. Both extreme low and high temperatures affect Anopheles mosquito development and survival. Climate change could have diverse effects on Anopheles mosquitoes. There seems to be inconclusive evidence of the effects of temperature on the development and survival of Anopheles species, and more studies are needed to clarify this relationship.
ARTICLE | doi:10.20944/preprints202101.0396.v1
Subject: Engineering, Automotive Engineering Keywords: biofuel; biobutanol; ABE-fermentation; Clostridium; continuous reactor; process model; multi stage process
Online: 20 January 2021 (10:59:00 CET)
The production of butanol, acetone and ethanol by Clostridium acetobutylicum is a biphasic fer-mentation process. In the first phase the carbohydrate substrate is metabolized to acetic and bu-tyric acid, in the following second phase the product spectrum is shifted towards the economi-cally interesting solvents. Here we present a cascade of six continuous stirred tank reactors (CCSTR), which allows performing the time dependent metabolic phases of an ace-tone-butanol-ethanol (ABE) batch fermentation in a spatial domain. Experimental data of steady states under four operating conditions - with variations of the pH in the first bioreactor between 4.3 and 5.6 as well as the total dilution rate between 0.042 1/h and 0.092 1/h - were used to optimize and validate a corresponding mathematical model. Beyond a residence time distribution representation and substrate, biomass and product kinetics this model also includes the differen-tiation of cells between the metabolic states. Model simulations predict a final butanol product concentration of 8.2 g/L and a butanol productivity of 0.75 g/(L h) in the CCSTR operated at a pH in bioreactor 1 of 4.3 and D = 0.092 1/h, while 31 % of the cells are differentiated to the solventogenic state. Aiming at an enrichment of solvent-producing cells, a feedback loop was introduced into the cascade - sending cells from a later state of the process (bioreactor 4) back to an early stage of the process (bioreactor 2). In agreement with the experimental observations, the model accurately predicted an increase of butanol formation rate in bioreactor stages 2 and 3, resulting in an overall butanol productivity of 0.76 g/(L h) for the feedback loop cascade. The here presented CCSTR and the validated model will serve to investigate further ABE fermentation strategies for a controlled metabolic switch.
REVIEW | doi:10.20944/preprints202101.0033.v1
Subject: Engineering, Other Keywords: Desalination; Multi Effect Distillation; Multi Stage Flash; Vapor Compression Distillation; Renewable Energies.
Online: 4 January 2021 (12:33:03 CET)
Abstract: Thermal desalination is yet a reliable technology in the treatment of brackish water and seawater; however, its demanding high energy requirements have lagged it compared to other non-thermal technologies such as reverse osmosis. This review provides an outline of the development and trends of the three most commercially used thermal or phase change technologies worldwide: Multi Effect Distillation (MED), Multi Stage Flash (MSF), and Vapor Compression Distillation (VCD). First, state of water stress suffered by regions with little fresh water availability and existing desalination technologies that could become an alternative solution are shown. The most recent studies published for each commercial thermal technology are presented, focusing on optimizing the desalination process, improving efficiencies, and reducing energy demands. Then, an overview of the use of renewable energy and its potential for integration into both commercial and non-commercial desalination systems is shown. Finally, research trends and their orientation towards hybridization of technologies and use of renewable energies as a relevant alternative to the current problems of brackish water desalination are discussed. This reflective and updated review will help researchers to have a detailed state of the art of the subject and to have a starting point for their research, since current advances and trends on thermal desalination are shown.
REVIEW | doi:10.20944/preprints201909.0136.v1
Subject: Engineering, Other Keywords: land engineering; development stage; discipline uniqueness; theory system; subject matter; land science
Online: 14 September 2019 (12:14:38 CEST)
Land engineering is a specific new academic discipline in China. Although the undergraduate major of land engineering was officially approved and established lately since 2017, the birth of land engineering as an academic discipline dates back 40 years ago. It has passed through four development stages: the incubation stage in 1978-1985, the initial stage in 1986-1997, the growth stage in 1998-2011, and the expanding stage from 2012 to present. However, land engineering as an academic discipline remains immature and seriously lags behind practice. There are still no unified academic community and broad academic consensus. After a historical overview of the four development stages, this study gave a strategic consideration to five key questions. We argue that the study object of the discipline is land engineering activity, which is defined as the artificial transformation of a land complex combined by various natural and human elements. The uniqueness of the discipline is rooted in its ability to study the comprehensive and integrated reorganization or rebuilding of various elements of land as a complex, with the theory of land complex reconstruction being the core theory. The discipline of land engineering is based on land pure science and land technology, and is one basis of land management. It consists of two modules (rural land engineering and urban land engineering), five secondary disciplines of each module (land development, land rearrangement, land improvement, land protection, and land remediation), and more than 30 research directions. Various technologies are only instrumental but not essential components of land engineering as an academic discipline.
ARTICLE | doi:10.20944/preprints201906.0285.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: hepatocellular carcinoma; lenvatinib; transcatheter arterial chemoembolisation; intermediate stage; up-to-seven criteria
Online: 27 June 2019 (08:13:58 CEST)
Background: Although transcatheter arterial chemoembolisation (TACE) is the standard of care for intermediate-stage hepatocellular carcinoma (HCC), this is a largely heterogeneous disease that includes a subgroup of patients who do not benefit from TACE. The treatment strategy for this subgroup of patients currently remains an unmet need in clinical practice. Here, we performed a proof-of-concept study that lenvatinib may be more favourable treatment option over TACE as an initial treatment in intermediate-stage HCC patients with large or multinodular tumours exceeding the up-to-seven criteria. Methods: This proof-of-concept study included 642 consecutive patients with HCC initially treated with lenvatinib or conventional TACE (cTACE) between January 2006 and December 2018. Of these patients, 176 who received lenvatinib or cTACE as an initial treatment and met the eligibility criteria [unresectable, beyond the up-to-seven criteria, no prior TACE/systemic therapy, no vascular invasion, no extrahepatic spread and Child-Pugh A liver function] were selected for the study. Propensity score matching was used to adjust for patient demographics. Results: After propensity-score matching, outcome of 30 patients prospectively treated with lenvatinib (14 in clinical trials, 1 in early access program and 15 in real world setting) and 60 patients treated with cTACE as the initial treatment was compared. The change of ALBI score from baseline to the end of treatment were -2.61 to -2.61 for 30 patients in lenvatinib group (p = 0.254) and -2.66 to -2.09 in cTACE group (p < 0.01), respectively. The lenvatinib group showed a significantly higher objective response rate (73.3% vs. 33.3%; p < 0.001) and significantly longer median progression-free survival than the cTACE group (16.0 vs. 3.0 months; p < 0.001). Overall survival was significantly longer in the lenvatinib group than in the cTACE group (37.9 vs. 21.3 months; hazard ratio: 0.48, p < 0.01). Conclusion: In patients with large or multinodular intermediate-stage HCC exceeding the up-to-seven criteria with Child-Pugh A liver function, who usually do not benefit from TACE, lenvatinib provides more favorable outcome than TACE.
ARTICLE | doi:10.20944/preprints201710.0132.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: integrated forward/reverse logistics network; accelerated benders’ decomposition; two-stage stochastic programming
Online: 20 October 2017 (03:07:28 CEST)
In this paper, a two-stage stochastic programming modelling is proposed to design a multi-period, multistage, and single-commodity integrated forward/reverse logistics network design problem under uncertainty. The problem involves both strategic and tactical decision levels. The first stage deals with strategic decisions, which are the number, capacity, and location of forward and reverse facilities. At the second stage tactical decisions such as base stock level as an inventory policy is determined. The generic introduced model consists of suppliers, manufactures, and distribution centers in forward logistic and collection centers, remanufactures, redistribution, and disposal centers in reverse logistic. The strength of proposed model is its applicability to various industries. The problem is formulated as a mixed-integer linear programming model and is solved by using Benders’ Decomposition (BD) approach. In order to accelerate the Benders’ decomposition, a number of valid inequalities are added to the master problem. The proposed accelerated BD is evaluated through small-, medium-, and large-sized test problems. Numerical results reveal that proposed solution algorithm increases convergence of lower bound and upper bound of BD and is able to reach an acceptable optimality gap in a convenient CPU time.
ARTICLE | doi:10.20944/preprints201703.0003.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: neutral-point-clamped inverter; buck-boost inverter; single stage conversion; photovoltaic inverter
Online: 1 March 2017 (09:31:28 CET)
This paper proposes a novel single-stage buck-boost three-Level neutral-point-clamped (NPC) inverter with two independent dc sources coupled for the grid-tied photovoltaic (PV) application, which can effectively solve the unbalanced operational conditions generally appeared between two coupled independent PV sources induced by the unequal irradiation and temperature distribution. The proposed control scheme can simultaneously guarantee the maximum power point (MPP) operation of both PV sources and maintain the output waveform quality. Compared to the traditional two-stage PV inverter, the proposed NPC inverter could reduce the PV array voltage requirement and dc-link capacitors’ voltage rating, meanwhile show the advantage in operational efficiency. MATLAB simulations and the captured experimental results are presented to show the performance of the proposed three-level inverter.
ARTICLE | doi:10.20944/preprints201805.0140.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: fly-back converter; zero-voltage-switching (ZVS); Variable-frequency-controller (VFC); single-stage
Online: 9 May 2018 (07:43:25 CEST)
This paper proposes a single-stage asymmetrical half-bridge fly-back (AHBF) converter with resonant mode using dual-mode control. The presented converter has an integrated boost converter and asymmetrical half-bridge fly-back converter and operates in resonant mode. The boost-cell always operates in discontinuous conduction mode (DCM) to achieve high power factor. The presented converter operates simultaneously using a variable-frequency-controller (VFC) and pulse-width-modulation (PWM) controller. Unlike the conventional single-stage design, the intermediate bus voltage of this controller can be regulated depending on the main power switch duty ratio. The asymmetrical half-bridge fly-back converter utilizes a variable switching frequency controller to achieve the output voltage regulation. The asymmetrical half-bridge fly-back converter can achieve zero-voltage-switching (ZVS) operation and significantly reduce the switching losses. Detailed analysis and design of this single-stage asymmetrical half-bridge fly-back converter with resonant mode is described. A wide AC input voltage ranging from 90 to 264 Vrms and output 19 V/ 120 W prototype converter was built to verify the theoretical analysis and performance of the presented converter.
ARTICLE | doi:10.20944/preprints202210.0005.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: intrahepatic cholangiocarcinoma; 18F-fluorodeoxyglucose positron emission tomography; computer tomography; magnetic resonance imaging; tumor stage
Online: 3 October 2022 (12:08:53 CEST)
18F-fluorodeoxyglucose positron emission tomography and computed tomography (18F-FDG PET-CT) is increasingly used in the diagnosis, prognosis, staging, and treatment monitoring of many tumor types. However, only a small number of studies have reported the use of 18F-FDG PET-CT in intrahepatic cholangiocarcinoma (ICC). This study aimed to examine the accuracy of tumor staging in ICC by using 18F-FDG PET-CT. Between January 2009 and December 2020, patients with suspected ICC were retrospectively enrolled in the study and underwent imaging. The sensitivity and specificity of 18F-FDG PET-CT, CT, and magnetic resonance imaging (MRI) in detecting tumors, satellite focus, vascular invasion, and lymph node metastases were analyzed. The efficacy of 18F-FDG PET-CT for tumor staging was evaluated. Of the 110 patients who were enrolled in the study, 52 underwent surgical treatment and 45 were histologically diagnosed with ICC. When compared with CT or MRI, 18F-FDG PET-CT had similar sensitivity and specificity values for diagnosing satellite focus and vascular and bile duct invasion; however, PET-CT showed higher accuracy in diagnosing regional lymph node metastases. The accuracy of tumor staging by 18F-FDG PET-CT was higher than that by CT/MRI. Thus, 18FDG PET-CT may support tumor staging in ICC.
REVIEW | doi:10.20944/preprints202102.0168.v1
Subject: Biology, Anatomy & Morphology Keywords: aquaculture; shellfish; future food; nursery stage; mud crab; juvenile; seed production; hatchery; crablet; breeding
Online: 5 February 2021 (16:18:19 CET)
This study attempted to explain the definition, objectives, and key stages in mud crab nursery activities. The nursery stages of Scylla spp was started from megalopa stage to several crablet instar stages or started from earlier crablet stage to several crablet stages. Direct stocking of megalopa into ponds is not recommended due to their sensitivity. Instead, nursery rearing is needed to produce mud crab of larger size before stocking. Individual nursery rearing results in higher survival rate (up to 100%), but with reduced growth rate, and a more complicated maintenance process compared with communal rearing. Nursery of mud crab can be done indoors, or outdoors, with adequate shelter and feed required to obtain good survival and growth performance. Artemia nauplii are the main, established nursery feed, particularly at megalopa stage, while survival rate may be improved if combined with artificial feed, such as micro bound diet formulations. Water quality parameters, identical to those proposed in tiger shrimp culture, can followed. Crablets may be transported to the pond location with, or without water. The provision of monosex seeds from mud crab hatcheries is expected to become more common, increasing seed price, and thus improving income of farmers. Numerous aspects of mud crab nursery, including nutrition, feeding strategies, understanding of their behaviour, i.e., cannibalism, control of environmental factors, and practical rearing techniques, still need further improvement.
Subject: Medicine & Pharmacology, Allergology Keywords: Dyalisis in pregnancy; End stage renal disease; haemodyalisis; peritoneal dyalisis; intensive dyalisis regimen; preeclampsia
Online: 30 December 2020 (16:55:39 CET)
Background. Pregnancy rates in women on dialysis have increased in the last decades, thus making it a topic of growing interest. The rarity of this event is predominantly due to fertility problems and to the high rates of pregnancy failure including stillbirth, fetal and neonatal deaths . Methods. We conducted a narrative review of existent literature in order to analyse the major issues about pregnancy on dialysis to give the reader a full updated prospective about this topic which, even if not common, is becoming more and more frequent. Results. Even if recently acquired knowledge has improved diagnosis and treatment of dialysis pregnancies focusing on several aspects, pregnancy on dialysis remains a great challenge for obstetricians and should be managed by a multidisciplinary expertise team. Conclusion. Dialysis in pregnancy may be necessary for women previously affected by end stage renal disease (ESRD) becoming pregnant, or in case of acute renal injury presenting for the first time during gestation or, again in case of existent renal pathology worsening during pregnancy and requiring dialysis. Although some evidence suggests that more intensive dialysis regimens are correlated with better obstetric outcomes, the optimal therapeutic protocol still remains to be established.
ARTICLE | doi:10.20944/preprints201906.0200.v2
Subject: Engineering, Electrical & Electronic Engineering Keywords: smart meters; low voltage distribution networks; energy losses; three-stage algorithm; typical load profiles
Online: 24 June 2019 (10:43:32 CEST)
In the paper, an improved smart meter data-based three-stage algorithm to calculate the power/energy losses in the three-phase networks with the voltage level below 0.4 kV (low voltage - LV) is presented. In the first stage, a loading function of input data was built having as main feature the working at the same time with files from the database of smart metering system (SMS) containing the hourly electricity records, and files including the characteristic load profiles established by the Distribution Network Operator (DNO) for the consumers with standard energy meters depending the following factors: consumption class, day and season. In the second stage, a function which is based on the work with the structure vectors was implemented to identify easy the configuration of analysed networks. In the third stage, an improved version of forward/backward sweep-based algorithm was proposed to calculate fast the power/energy losses to three-phase LV distribution networks in balanced and unbalanced regime. A real LV rural distribution network from a pilot zone belonging to a Distribution Network Operator (DNO) from Romania was used to confirm the accuracy of the proposed approach. The comparison with the results obtained using the DigSilent PowerFactory Simulation Package certified the performance of the algorithm, the mean absolute percentage error (MAPE) being 0.94%.
ARTICLE | doi:10.20944/preprints201612.0092.v1
Subject: Biology, Ecology Keywords: Anaea aidea; caterpillar demography; multi-state mark-recapture; state-space model; stage-structured matrix
Online: 18 December 2016 (09:33:13 CET)
Organisms in the wild have cryptic life stages that are sensitive to changing environmental conditions and can be difficult to survey. In this study, I used mark-recapture methods to repeatedly survey Anaea aidea (Nymphalidae) caterpillars in nature, then modeled caterpillar demography as a hidden Markov process to assess if temporal variability in temperature and density influence the survival and growth of A. aidea over time. Individual encounter histories result from the joint likelihood of being alive and observed in a particular stage, and I included hidden states by separating demography and observations into parallel and independent processes. I constructed a demographic matrix containing the probabilities of all possible fates for each stage, including hidden states, e.g., eggs and pupae. I observed both dead and live caterpillars with high probability. Peak caterpillar abundance attracted multiple predators, and survival of fifth instars declined as per capita predation rate increased through spring. A time lag between predator and prey abundance was likely the cause of improved fifth instar survival estimated at high density. Growth rates showed an increase with temperature, but the most likely model did not include temperature. This work illustrates how state-space models can include unobservable stages and hidden state processes to evaluate how environmental factors influence vital rates of cryptic life stages in the wild.
CASE REPORT | doi:10.20944/preprints202209.0161.v1
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: Antibody-mediated rejection; Crossmatch; Daratumumab; End-stage renal disease; Flow cytometry; HLA; Multiple myeloma; Transplantation
Online: 13 September 2022 (05:48:27 CEST)
We report the first case of Daratumumab interference of allogeneic crossmatch tests repeatedly causing aberrant false-positive results, which inadvertently delayed transplant for a waitlisted renal patient with multiple myeloma. Daratumumab is an IgG1κ human monoclonal antibody commonly used to treat multiple myeloma, characterized by cancerous plasma cells and often leads to renal failure requiring kidney transplant, by depleting CD38-expressing plasma cells. In this case study, the patient had end-stage renal disease secondary to multiple myeloma and was continuously receiving Daratumumab infusions. The patient did not have any detectable antibodies to human leukocyte antigens but repeatedly had unexpected positive crossmatch by the flow cytometry-based method with 26 of the 27 potential deceased organ donors, implying donor-recipient immunological incompatibility. However, further review and analysis suggested that the positive crossmatches were likely false-positive as a result of interference from Daratumumab binding to donor cell surface CD38 as opposed to the presence of donor-specific antibodies. The observed intensity of the false-positive crossmatches was also highly variable, potentially due to donor- and/or cell-dependent expression of CD38. The variability of CD38 expression was, therefore, for the first time, characterized on the T and B cells isolated from various tissues and peripheral blood of 78 individuals. Overall, T cells were found to have a lower CD38 expression profile than the B cells, and no significant difference was observed between deceased and living individuals. Finally, we show that a simple cell treatment by dithiothreitol can effectively mitigate Daratumumab interference thus preserving the utility of pre-transplant crossmatch in multiple myeloma patients awaiting kidney transplant.
ARTICLE | doi:10.20944/preprints202112.0025.v2
Subject: Engineering, Other Keywords: Brain segmentation; Coarse-to-fine; Gen- erative Adversarial Network; Semi-supervised learning; Multi-stage method
Online: 6 December 2021 (14:33:23 CET)
Image segmentation is a new challenge prob- lem in medical application. The use of medical imaging has become an integral part of research, as it allows us to see inside the human body without surgical intervention. Many researcher have studied brain segmentation. One stage method is used to segment the brain tissues. In this paper, we proposed the multi-stage generative ad- versarial network to solve the problem of information loss in the one-stage. We utilize the coarse-to-fine to improve brain segmentation using multi-stage generative adversar- ial networks (GAN). In the first stage, our model generated a coarse outline for (i) background and (ii) brain tissues. Then, in the second stage, the model generated outline for (i) white matter (WM), (ii) gray matter (GM) and (iii) cerebrospinal fluid (CSF). A good result can be achieved by fusing the coarse outline and refine outline. We conclude that our model is more efficient and accu- rate in practice for both infant and adult brain segmenta- tion. Moreover, we observe that multi-stage model is faster than prior models. To be more specific, the main goal of multi-stage model is to see the performance of the model in a few shot learning case where a few labeled data are available. For medical image, this proposed model can work in a wide range of image segmentation where the convolution neural networks and one-stage methods have failed.
ARTICLE | doi:10.20944/preprints202106.0120.v1
Subject: Earth Sciences, Atmospheric Science Keywords: IMERG; Stage IV; Infrared; Passive microwave; Snow; Ice; Precipitation; GPM; Wet-bulb temperature; AMSR-2
Online: 3 June 2021 (14:59:21 CEST)
Various products of the Integrated Multisatellite Retrievals for GPM (IMERG) and passive mi-crowave (PMW) sensors are assessed with respect to near-surface wet-bulb temperature (Tw), precipitation intensity, and surface type (i.e., with and without snow and ice on the surface) over the CONUS and using Stage-IV product as reference precipitation. IMERG products include precipitation estimates from infrared (IR), combined PMW, and their combination. PMW products generally have higher skills than IR over snow- and ice-free surfaces. Over snow- and ice-covered surfaces (1) PMW products (except AMSR-2) show a higher correlation coefficient than IR, (2) IR and PMW precipitation products tend to overestimate precipitation, but at colder temperatures (e.g., Tw<-10oC) PMW products tend to underestimate and IR product continues to show large overestimations, and (3) PMW sensors show higher overall skill in detecting precipitation oc-currence, but not necessarily at very cold Tw. The results suggest that the current approach of IMERG (i.e., replacing PMW with IR precipitation estimates over snow- and ice-surfaces) may need to be revised.
ARTICLE | doi:10.20944/preprints202102.0068.v1
Subject: Medicine & Pharmacology, Allergology Keywords: cost-effectiveness; pembrolizumab; etoposide-platinum; extensive-stage small-cell lung cancer; small cell lung cancer.
Online: 1 February 2021 (18:10:59 CET)
Background: The phase III KEYNOTE-604 study confirmed the benefit of pembrolizumab combined with chemotherapy in the first-line treatment of extensive-stage small-cell lung cancer(ES-SCLC). Intergrated the clinical benefits of pembrolizumab and its high cost into account, this study aim to assess the cost-effectiveness of adding pembrolizumab to standard first-line etoposide-platinum (EP) for patients with ES-SCLC from the the US payer perspective. Methods: A Markov model was developed to compared the costs and quality-adjusted life-years (QALYs) of pembrolizumab plus EP and placebo plus EP over a 10-year time horizon. Clinical efficacy, treatment utilization and safety data were pooled from the KEYNOTE-604 trial. Utilities were obtained from published resources. Costs were mainly collected from Medicare in 2020. Sensitivity analyses were performed to examined the robustness of our model. Results: Adding pembrolizumab to standard first-line EP, resulted in better effectiveness than the use of EP alone for ES-SCLC by 0.22 QALYs. Pembrolizumab plus EP was dominated economically by placebo plus EP, leading to an incremental cost-effectiveness ratio(ICER) of $334,373/ QALY. Deterministic sensitivity analyses indicated that the uncertainty in model parameters exerts no substantial effect on our results. Probability sensitivity analysis indicated that probabilities for pembrolizumab plus EP being cost-effective within a wide rang of willingness to pay were modest. Conclusion: From the US payer perspective, the first-line treatment for ES-SCLC with pembrolizumab plus EP was not cost-effective compare with placebo plus EP. Although pembrolizumab combination chemotherapy was beneficial to the survival of ES-SCLC, price reduction may be the necessary measure to improve its cost-effectiveness.
ARTICLE | doi:10.20944/preprints201912.0246.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: fluoropyrimidine; metronomic maintenance therapy; oxaliplatin-based regimen; stage III colorectal cancer; epidermal growth factor receptor
Online: 19 December 2019 (07:04:39 CET)
Background: This retrospective study evaluates the survival effects of metronomic maintenance therapy with fluoropyrimidine in patients with stage III colorectal cancer (CRC) according to epidermal growth factor receptor (EGFR) expression. Methods: We enrolled 197 patients with stage III CRC who had undergone radical resection and FOLFOX regimen adjuvant chemotherapy. The clinicopathological features and effects of metronomic maintenance therapy on survival according to treatment group and EGFR expression were analyzed. By conducting an in vitro cell line study and in vivo study through knockdout of EGFR gene, we analyzed the capacities of cell proliferation and migration. Results: Postoperative relapse and mortality were significantly more common in the FOLFOX group. Metronomic maintenance therapy was a significantly independent predictive factor of postoperative relapse and mortality, as well as a prognostic factor of disease-free survival and overall survival. The significant differences of survival between the two groups were only observed in patients with positive EGFR expression. Conclusions: The present study suggested EGFR expression as the prognostic factor in patients with stage III CRC receiving metronomic maintenance therapy. By analyzing EGFR expression, we can identify the potential candidates with optimal survival benefit from metronomic maintenance therapy in patients with stage III CRC.
ARTICLE | doi:10.20944/preprints201909.0036.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: fluoropyrimidine; metronomic maintenance therapy; oxaliplatin-based regimen; stage III colorectal cancer; epidermal growth factor receptor
Online: 4 September 2019 (00:53:56 CEST)
Background: This retrospective study evaluate the survival effects of metronomic maintenance therapy with fluoropyrimidine in patients with stage III colorectal cancer (CRC) according to epidermal growth factor receptor (EGFR) expression. Methods: We enrolled 197 patients with stage III CRC who had undergone radical resection and FOLFOX regimen adjuvant chemotherapy. The clinicopathological features and effects of metronomic maintenance therapy on survival according to treatment group and EGFR expression were analyzed. By conducting an in vitro cell line study and in vivo study through knockdout of EGFR gene, we analyzed the capacities of cell proliferation and migration. Results: Postoperative relapse and mortality were significantly more common in the FOLFOX group. Metronomic maintenance therapy was a significantly independent predictive factor of postoperative relapse and mortality, as well as a prognostic factor of disease-free survival and overall survival. We also demonstrated that EGFR-knockout Caco2 cells are more sensitive to the inhibition effect of fluoropyrimidine than the control those. Conclusions: The present study suggested EGFR expression as the prognostic factor in patients with stage III CRC receiving metronomic maintenance therapy. By analyzing EGFR expression and treatment strategies, we can identify the potential candidates with optimal survival benefit from metronomic maintenance therapy in patients with stage III CRC.
REVIEW | doi:10.20944/preprints202011.0372.v1
Subject: Medicine & Pharmacology, Allergology Keywords: SARS-CoV-2; Covid-19; Antiviral Drugs; Immunomodulators; Neutralizing Antibody Therapy; Cell Therapy; Current Vaccine Stage
Online: 13 November 2020 (12:30:08 CET)
Severe Acute Respiratory Syndrome Coronavirus 2(SARS-CoV-2) is the virus that caused COVID-19 around the world. The disease starts off as a flu-like symptom and then eventually spreads in the human body.Infections are easily transmitted from human to human which makes it more severe among individuals. SARS-CoV-2 virus is in the same family of viruses SARS and MERS.As of today, there is no approved vaccine that can cure COVID-19. However, potential treatments showing promising improvement results among affected COVID-19 patients. In this review, the effectiveness of the current treatments for COVID-19 has been explored.
ARTICLE | doi:10.20944/preprints201809.0529.v1
Subject: Life Sciences, Biotechnology Keywords: hemodialysis; end stage renal disease; diabetes; motor performance; gait; balance; wearable; aging; frailty; diabetic peripheral neuropathy
Online: 27 September 2018 (04:19:43 CEST)
Motor functions are deteriorated by aging. Some conditions may magnify this deterioration. To examine whether hemodialysis (HD) process would negatively impact gait and balance beyond diabetes condition among mid-age adults (48-64 years) and older adults (65+ years). One hundred and ninety-six subjects (age=66.2±9.1 years, body-mass-index=30.1±6.4 kg/m2, female=56%) in 5 groups were recruited: mid-age adults with diabetes undergoing HD (Mid-age HD+, n=38) and without HD (Mid-age HD-, n=40); older adults with diabetes undergoing HD (Older HD+, n=36) and without HD (Older HD-, n=37); and non-diabetic older adults (Older DM-, n=45). Gait parameters (stride velocity, stride length, gait cycle time, and double support) and balance parameters (ankle, hip, and center of mass sways) were quantified using validated wearable platforms. Groups with diabetes had overall poorer gait and balance compared to the non-diabetic group (p<0.050). Among people with diabetes, the HD+ had significantly worsened gait and balance when comparing to the HD- (Cohen’s effect size d=0.63-2.32, p<0.050). Between-group difference was more pronounced among older adults with the largest effect size observed for stride length (d=2.32, p<0.001). Results suggested that deterioration in gait speed among the HD+ was correlated with age (r=-0.440, p<0.001), while this correlation was diminished among the HD-. Interestingly, results also suggested that poor gait in the Older HD- related to poor balance, while no correlation was observed between poor balance and poor gait among the Older HD+. Using objective assessments, results confirmed that the presence of diabetes can deteriorate gait and balance, and this deterioration can be magnified by HD process. Among non-HD people with diabetes, poor static balance described poor gait. However, among people with diabetes undergoing HD, age was a dominate factor describing poor gait irrespective of static balance. Results also suggested feasibility of using wearable platforms to quantify motor performance during routine dialysis clinic visits. These objective assessments may assist in identifying early deterioration in motor function, which in turn may promote timely intervention.
ARTICLE | doi:10.20944/preprints201608.0148.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: ac–dc power converters; battery chargers; dual active bridge; DAB; optimal design; power MOSFETs; single-stage
Online: 15 August 2016 (11:06:09 CEST)
The growing attention for plug-in electric vehicles, and the associated high-performance demands, have initiated a development trend towards highly efficient and compact on-board battery chargers. These isolated ac-dc converters are most commonly realized using two conversion stages, combining a non-isolated power factor correction (PFC) rectifier with an isolated dc-dc converter. This, however, involves two loss stages and a relatively high component count, limiting the achievable efficiency and power density and resulting in high costs. In this paper a single-stage converter approach is analyzed to realize a single-phase ac-dc converter, combining all functionalities into one conversion stage and thus enabling a cost-effective efficiency and power density increase. The converter topology consists of a quasi-lossless synchronous rectifier followed by an isolated dual active bridge (DAB) dc-dc converter, putting a small filter capacitor in between. To show the performance potential of this bidirectional, isolated ac-dc converter, a comprehensive design procedure and multi-objective optimization with respect to efficiency and power density is presented, using detailed loss and volume models. The models and procedures are verified by a 3.7 kW hardware demonstrator, interfacing a 400 V dc-bus with the single-phase 230 V, 50 Hz utility grid. Measurement results indicate a state-of-the-art efficiency of 96.1% and power density of 2.2 kW/dm3, confirming the competitiveness of the investigated single-stage DAB ac-dc converter.
ARTICLE | doi:10.20944/preprints202104.0276.v1
Subject: Engineering, Automotive Engineering Keywords: log microcircuit; differential stage; complementary field-effect transistors with control p-n junction; low temperatures; neutron flux
Online: 12 April 2021 (09:40:03 CEST)
The circuitry of the summarized "floating" differential stages (FDS) based on complementary field-effect transistors with a control p-n junction (CJFET), intended for use in low-noise analog microcircuits, for example, operational amplifiers. The results of modeling the flow characteristics of one of the CJFET FDSs in the LTSpice XVII environment at low temperatures (down to -197 0С) and exposure to a neutron flux in the range of 1e13 ÷ 1e15 n / cm2 are presented.
ARTICLE | doi:10.20944/preprints201909.0236.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: arpi; p&o-based mppt; variable dc-link; single-stage; three-level three-phase inverter; grid connection
Online: 20 September 2019 (10:35:43 CEST)
The article introduces a new solution approach to grid-connected single-stage three-phase PV inverter whereby a dc-link voltage can successfully achieve the desired performance. As a single-stage, the variable output of perturb and observe maximum power point tracking (P&O based-MPPT) is fully utilized as dc-link voltage reference in inverter control scheme. As a result, it is challenging for the dc-link voltage to preserve energy balance by tracking its variable dc-link voltage reference under unpredictable environmental changes. To overcome this challenge, an adaptive reference proportional-integral (ARPI) controller, self-tuning, is designed and implemented to compel the dc-link voltage tracking its voltage reference to be equal as closely as possible; hence, the capability of the dc-link under abnormal events substantially guarantees the best energy balance and transient performance enhancement. To verify the validity of the method, simulation results for multiple events scenarios on 250 KW single-stage grid-connected PV systems show the effectiveness of the ARPI controller compared with PI controller.
ARTICLE | doi:10.20944/preprints201909.0160.v1
Subject: Engineering, Mechanical Engineering Keywords: geometric errors; rigid body kinematics; lateral stage errors; Imaging Confocal Microscope; MCM uncertainty evaluation; dot grid target
Online: 16 September 2019 (10:43:59 CEST)
This paper presents the experimental implementations of the mathematical models and algorithms developed in Part I. Two experiments are carried out. The first experiment aims at the determinations of the correction coefficients of the mathematical model. The dot grid target is measured and the measurement data are processed by our developed and validated algorithms introduced in Part I. The values of the coefficients are indicated and analysed. Uncertainties are evaluated with implementation of the Monte Carlo method. The second experiment measures a different area of the dot grid target. The measurement results are corrected according to the coefficients determined in the first experiment. The mean residual between the measured points and their corresponding certified values reduced 29.6% after the correction. The sum of squared errors reduced 47.7%. The methods and the algorithms for raw data processing, such as data partition, fittings of dots’ centres, K-means clustering, etc., are the same for both two experiments. The experimental results demonstrate that our method for the correction of the errors produced by the movement of lateral stage of confocal microscope is meaningful and practicable.
ARTICLE | doi:10.20944/preprints201906.0271.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: chronic kidney disease; disease progression; end stage renal disease; mortality; health-related behaviors; physical activity; smoking; alcohol
Online: 26 June 2019 (15:38:12 CEST)
Healthy life style is associated with decreased risk of chronic kidney disease (CKD) and mortality in the general population. However, there is no definitive evidence on the benefits of physical activity and other health-related behaviors in the early-stage CKD. This study aimed to explore the association between health-related behaviors and end-stage renal disease (ESRD) and mortality in the early stages of CKD. The National Health Insurance Service (NHIS) database from January 1st, 2009 to December 31st, 2016 was used to screen 83,470 subjects with early stage CKD. Cox proportional hazard regression analysis was used to evaluate the association between health-related behaviors and ESRD and death. Kaplan-Meier curves for mortality and ESRD were plotted according to the physical activity, smoking status and alcohol consumption pattern. Risk of death decreased significantly in subjects who engaged in sufficient physical activity (adjusted Hazard Ratio (HR) 0.73; 95% CI: 0.64-0.83; p < 0.001). Risk of ESRD and death increased significantly in the current smoker with adjusted HR of 1.44 (95% CI: 1.06-1.95; p < 0.02) and 1.61 (95% CI: 1.44-1.80; p < 0.001) respectively. Therefore, systematic interventions to encourage physical activity and smoking cessation need to be actively considered in the early stages of CKD.
ARTICLE | doi:10.20944/preprints201806.0277.v1
Subject: Engineering, Energy & Fuel Technology Keywords: battery charger; photovoltaic module array; LiFePO4 battery; Buck converter; maximum power point tracker; smart two-stage charging strategy
Online: 18 June 2018 (15:55:50 CEST)
This paper aims to present a smart high speed battery charger, powered by a photovoltaic module array, for a LiFePO4 battery as a solar energy storage device. With a battery charging strategy, the presented battery charger involves a Buck converter as the core equipped with a simple maximum power point (MPP) tracker. Considering complexity reduction and easy hardware implementation, a constant voltage MPP tracking approach is adopted such that the maximum amount of output power can be delivered to the load in response to an arbitrary change in the solar radiation. A smart two-stage charging strategy, with a constant current mode followed by a constant voltage mode, is employed in such a way that the battery charge process can be accelerated largely, while the damage caused by overcharging can be prevented. In the end, the performance of this proposal is validated experimentally.
ARTICLE | doi:10.20944/preprints202102.0296.v1
Subject: Medicine & Pharmacology, Allergology Keywords: End-Stage Renal Disease, Chronic Kidney Disease, Wnt-Pathway, R-Spondin 1, β-Catenin, Dickkopf-Related Protein 1, and Sclerostin.
Online: 12 February 2021 (10:08:22 CET)
Background. Wnt-pathway proteins play a vital role in kidney development and defects in the Wnt-pathway are associated with kidney disorders. However, the knowledge on the role of Wnt/β-catenin pathway proteins in end-stage renal disease (ESRD) is limited.Aim of the study. To delineate the association of ESRD and Wnt-proteins including the agonistR-spondin 1, the transducer β-catenin and the antagonists Dickkopf-related protein 1 (DKK1) and sclerostin.Methods. Serum Wnt-pathway proteins levels were measured by ELISA, while other biochemicals were measured spectrophotometrically in 60 ESRD patients and 30 normal controls.Results. DKK1 and sclerostin were significantly higher in ESRD than in controls, and β-catenin and the catenin + R-Sponin-1 / DKK1 + sclerostin ratio, reflecting the ratio of agonist and transducer on antagonists (AT/ANTA), were significantly lower in ESRD. Logistic regression analysis showed that ESRD was significantly predicted by increased levels of DDK1 and sclerostin and lowered β-catenin (p<0.001). eGFR was significantly associated with DKK1 and sclerostin (inversely), β-catenin (positively) and the AT/ANTA ratio (r=0.468, p<0.001). DKK1 levels were significantly and positively correlated with urea, creatinine, and copper. DKK1 and sclerostin were inversely associated with hemoglobin and packet cell volume. Catenin was significantly negatively associated with copper, urea and creatinine.Conclusion. Wnt/β-catenin pathway proteins show significant alterations in ESRD, indicating significantly increased levels of antagonists and, therefore, attenuated Wnt/β-catenin pathway activity. The latter is associated with lowered eGFR and increased serum copper levels. Wnt/β-catenin pathway proteins are possible drug targets to treat ESRD or its consequences.
Subject: Engineering, Control & Systems Engineering Keywords: energy efficiency; building automatic control; energy use under field conditions; two-stage construction process; cost-benefit evaluation; deep retrofit of residential buildings
Online: 5 July 2020 (04:55:24 CEST)
Only now, four decades after passive houses were designed in the US and built in Canada, the authors are able to discuss the next generation of new and retrofitted buildings in the same way. This paper presents a universal system for different types of buildings and climates that includes construction experience and is reinforcing multi-disciplinary synergies. A next generation of technology uses adaptable indoor climate, integrates HVAC and building structure; applies field monitoring of energy and indoor environment and develops a performance model that is based on artificial neutral network. This approach, includes: 1. The self-learning ANN as a part of the building management system, 2. This management system guides energy optimization in a post-construction stage 3. A two-stage construction process for new and retrofits. The first stage prescribes investment level and optimizes performance; opposite in the second stage. This paper highlights that some elements of the proposed methodology have already been applied in the practice. It also underlines that this integrated multi-disciplinary system can be applied with a different combination of technological elements.
ARTICLE | doi:10.20944/preprints201705.0043.v1
Subject: Mathematics & Computer Science, Information Technology & Data Management Keywords: Bayesian reliability analysis; Bayesian hierarchical model; MCMC method; scale mixtures of log-normal failure time model; stochastic constraint; two-stage MaxEnt prior.
Online: 4 May 2017 (16:26:10 CEST)
This paper develops Bayesian inference in reliability of a class of scale mixtures of log-normal failure time (SMLNFT) models with stochastic (or uncertain) constraint in their reliability measures. The class is comprehensive and includes existing failure time (FT) models (such as log-normal, log-Cauchy, and log-logistic FT models) as well as new models that are robust in terms of heavy-tailed FT observations. Since classical frequency approaches to reliability analysis based on the SMLNFT model with stochastic constraint are intractable, the Bayesian method is pursued utilizing a Markov chain Monte Carlo (MCMC) sampling based approach. This paper introduces a two-stage maximum entropy (MaxEnt) prior, which elicits a priori uncertain constraint and develops Bayesian hierarchical SMLNFT model by using the prior. The paper also proposes an MCMC method for Bayesian inference in the SMLNFT model reliability and calls attention to properties of the MaxEnt prior that are useful for method development. Finally, two data sets are used to illustrate how the proposed methodology works.
ARTICLE | doi:10.20944/preprints202212.0004.v1
Subject: Medicine & Pharmacology, Other Keywords: SMI (silicone mammary implants); FBR (foreign body response); wound healing; wound infection; capsular fibrosis; implant encapsulation; early-stage fibrosis; surface adsorption; immunomics; biomarkers
Online: 1 December 2022 (02:02:11 CET)
The etiology of exaggerated fibrous capsule formation around silicone mammary implants (SMI) is multifactorial but primarily induced by immune mechanisms toward the foreign material silicone. The aim of this work was to enlighten the disease progression from implant insertion and immediate tissue damage response reflected in (a) the acute wound proteome, and (b) the adsorption of chronic inflammatory wound proteins at implant surfaces. An intra-individual absolute quantitation TMT-liquid chromatography-tandem mass spectrometry approach was applied to profile wound proteome formed around SMI the first five days post-implantation. Compared to plasma, the acute wound profile resembled a more complex composition comprising plasma-derived and locally differentially expressed proteins (DEPs). DEPs were subjected to functional enrichment analysis, which revealed the dysregulation of signaling pathways mainly involved in immediate inflammation response and ECM turnover. Moreover, we found time-course variations in protein enrichment immediately post-implantation and adsorbed to SMI surfaces after 6-8 months. Characterization of the expander-adhesive proteome by label-free approach uncovered a long-term adsorbed acute wound and the fibrosis-associated proteome. Our findings propose a wound biomarker panel for the early detection and diagnosis of excessive fibrosis that could potentially broaden insights into the characteristics of fibrotic implant encapsulation.
ARTICLE | doi:10.20944/preprints202204.0235.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: operational amplifier; compensation of the systematic component of the zero offset voltage; differential stage; buffer amplifier; current mirror; reference current source; BJT transistors; GaAs transistors.
Online: 26 April 2022 (10:33:53 CEST)
The zero offset voltage in anti-aliasing low-pass filters (LPF) included at the ADC input has a significant effect on the effective bit rate of the ADC. The article discusses methods for minimizing the systematic component of the zero offset voltage (VOS) of operational amplifiers (Op-Amp) in the structure of the LPF, due to the degradation of the current gain of the base (b) of bipolar transistors for an extremely common subclass of Op-Amp with one high-impedance node. The methods of matching a high-impedance Op-Amp node and a buffer amplifier with the help of special correcting SCMp and SCMn multipolars are proposed. Methods of description and formation of the given coefficients of weak current asymmetry of typical Op-Amp functional units (current mirrors, input DS, buffer amplifiers, SRC, etc.) are presented. As an example, the results of computer simulation of GaAs Op-Amp with small VOS performed on JFET field and p-n-p bipolar transistors are given.
ARTICLE | doi:10.20944/preprints202012.0312.v1
Subject: Engineering, Automotive Engineering Keywords: Bayesian Network; Root Cause Analysis; Failure Mode and Effect Analysis; Lithium-Ion 15 Battery Cell; Failure Propagation; Multi-Stage Production; Manufacturing Process; Process Optimization; Scrap Rate
Online: 14 December 2020 (09:31:30 CET)
The production of lithium-ion battery cells is characterized by a high degree of complexit due to numerous cause-effect relationships between process characteristics. Knowledge about the multi-stage production is spread among several experts, rendering tasks such as failure analysis challenging. In this paper, a method is presented, which includes expert knowledge acquisition in production ramp-up by combining Failure Mode and Effects Analysis (FMEA) with a Bayesian Network. We show the effectiveness of this holistic method by building up a large scale, cross-process Bayesian Failure Network in lithium-ion battery production. Using this model, we are able to conduct root cause analyses as well as analyses of failure propagation. The former support operators in identifying root causes once a cell possesses a specific failure by calculating most-probable explanations matched to the individual battery cell data. The latter enable us to analyze propagation of failures and deviations in the production chain and thus provide support for placement of quality gates, leading to a significant reduction in scrap rate. Moreover, it gives an insight into which process steps are key drivers for which final product characteristics.