bluuebunny/crossref_metadata_2025 huggingface dataset:
Wide Load Range ZVS Three-level DC-DC Converter: Modular Structure, Redundancy Ability, and Reduced Filters Size
Authors: Shi Yong , Xu Zhuoyi
Published: September 2019

In future dc distributed power systems, high performance high voltage dc-dc converters with redundancy ability are welcome. However, most existing high voltage dc-dc converters do not have redundancy ability. To solve this problem, a wide load range zero-voltage switching (ZVS) three-level (TL) dc-dc converter is proposed, which has some definitely good features. The primary switches have reduced voltage stress, which is only Vin/2. Moreover, no extra clamping component is needed, which results simple primary structure. Redundancy ability can be obtained by both primary and secondary sides, which means high system reliability. With proper designing of magnetizing inductance, all primary switches can obtain ZVS down to 0 output current, and in addition, the added conduction loss can be neglected. TL voltage waveform before the output inductor is obtained, which leads small volume of the output filter. Four secondary MOSFETs can be switched in zero-current switching (ZCS) condition over wide load range. Finally, both the primary and secondary power stages are modular architecture, which permits realizing any given system specifications by low voltage, standardized power modules. The operation principle, soft switching characteristics are presented in this paper, and the experimental results from a 1 kW prototype are also provided to validate the proposed converter.
Modeling Experiments for Evaluating the Effects of Trees, Increasing Temperature, and Soil Texture on Carbon Stocks in Agroforestry Systems in Kerala, India
Authors: Russell Ann E. , Kumar B. Mohan
Published: September 2019

Research Highlights: Agroforestry systems in the humid tropics have the potential for high rates of production and large accumulations of carbon in plant biomass and soils and, thus, may play an important role in the global C cycle. Multiple factors can influence C sequestration, making it difficult to discern the effect of a single factor. We used a modeling approach to evaluate the relative effects of individual factors on C stocks in three agricultural systems in Kerala, India. Background and Objectives: Factors such as plant growth form, management, climate warming, and soil texture can drive differences in C storage among cropping systems, but the relationships among these factors and their effects are complex. Our objective was to use CENTURY, a process-based model of plant–soil nutrient cycling, in an experimental mode to evaluate the effects of individual factors on C stocks in soil and biomass in monocultures (annuals or trees) and agroforestry systems. Materials and Methods: We parameterized the model for this region, then conducted simulations to investigate the effects on C stocks of four experimental scenarios: (1) change in growth form; (2) change in tree species; (3) increase in temperature above 20-year means; and (4) differences in soil texture. We compared the models with measured changes in soil C after eight years. Results: Simulated soil C stocks were influenced by all factors: growth form; lignin in tree tissues; increasing temperature; and soil texture. However, increasing temperature and soil sand content had relatively small effects on biomass C. Conclusions: Inclusion of trees with traits that promoted C sequestration such as lignin content, along with the use of best management practices, resulted in the greatest C storage among the simulated agricultural systems. Greater use and better management of trees with high C-storage potential can thus provide a low-cost means for mitigation of climate warming.
Metallothioneins in Failure of Dental Implants and Periodontitis Down Syndrome Patients
Authors: Baus-Domínguez Maria , Gómez-Díaz Raquel , Corcuera-Flores Jose-Ramón , Torres-Lagares Daniel , Ruiz-Villandiego José-Cruz , Machuca-Portillo Guillermo , Gutiérrez-Pérez José-Luis , Serrera-Figallo María-Angeles
Published: September 2019

Background: Sometimes dental implants seem to be the only therapeutic alternative for the oral rehabilitation of patients with Down syndrome, given that they usually lose all their teeth early due to suffering aggressive periodontitis and they do not usually have the skills required to wear removable prostheses. However, the evolution of dental implants in these patients shows very adverse results. It is possible that basal genetic alterations, or at least some characteristics of these, may underlie these clinical results. The metabolic pathway of metallothioneins, molecules with an important influence on bone metabolism, could be one of the said alterations. Aims: To determine whether the expression of metallothioneins (MTs) and their metabolic pathway may be identified and related to the periodontitis and lack of osseointegration of dental implants in Down syndrome patients. Materials and Methods: Retrospective study of cases and controls by comparing patients with Down syndrome, periodontal disease, and implant failure (four patients, test group) with patients with Down syndrome, without periodontal disease, and without implant failure after two years of following (seven patients, control group), by extracting peripheral blood at the time of the dental examination to extract RNA and its subsequent processing in relation to gene expression of the metabolic pathway of metallothioneins. Results: The results identified low expression in the group of patients with periodontal disease and implant failure of genes MT1E, MT1H, MT1X, MT1A, MT1B, MT1C, MT1L, MT2A, MT1M, and MT1G. Conclusions: The low MT1 and MT2 gene expression seems to be related to the onset of periodontal disease and implant rejection in Down syndrome patients, although more data are required to confirm whether this relationship is due to one of the two conditions, to both independently, or to the two jointly—this last option being indicated by our current study.
NCBI’s Virus Discovery Hackathon: Engaging Research Communities to Identify Cloud Infrastructure Requirements
Authors: Connor Ryan , Brister Rodney , Buchmann Jan , Deboutte Ward , Edwards Rob , Martí-Carreras Joan , Tisza Mike , Zalunin Vadim , Andrade-Martínez Juan , Cantu Adrian , D’Amour Michael , Efremov Alexandre , Fleischmann Lydia , Forero-Junco Laura , Garmaeva Sanzhima , Giluso Melissa , Glickman Cody , Henderson Margaret , Kellman Benjamin , Kristensen David , Leubsdorf Carl , Levi Kyle , Levi Shane , Pakala Suman , Peddu Vikas , Ponsero Alise , Ribeiro Eldred , Roy Farrah , Rutter Lindsay , Saha Surya , Shakya Migun , Shean Ryan , Miller Matthew , Tully Benjamin , Turkington Christopher , Youens-Clark Ken , Vanmechelen Bert , Busby Ben
Published: September 2019

A wealth of viral data sits untapped in publicly available metagenomic data sets when it might be extracted to create a usable index for the virological research community. We hypothesized that work of this complexity and scale could be done in a hackathon setting. Ten teams comprised of over 40 participants from six countries, assembled to create a crowd-sourced set of analysis and processing pipelines for a complex biological data set in a three-day event on the San Diego State University campus starting 9 January 2019. Prior to the hackathon, 141,676 metagenomic data sets from the National Center for Biotechnology Information (NCBI) Sequence Read Archive (SRA) were pre-assembled into contiguous assemblies (contigs) by NCBI staff. During the hackathon, a subset consisting of 2953 SRA data sets (approximately 55 million contigs) was selected, which were further filtered for a minimal length of 1 kb. This resulted in 4.2 million (Mio) contigs, which were aligned using BLAST against all known virus genomes, phylogenetically clustered and assigned metadata. Out of the 4.2 Mio contigs, 360,000 contigs were labeled with domains and an additional subset containing 4400 contigs was screened for virus or virus-like genes. The work yielded valuable insights into both SRA data and the cloud infrastructure required to support such efforts, revealing analysis bottlenecks and possible workarounds thereof. Mainly: (i) Conservative assemblies of SRA data improves initial analysis steps; (ii) existing bioinformatic software with weak multithreading/multicore support can be elevated by wrapper scripts to use all cores within a computing node; (iii) redesigning existing bioinformatic algorithms for a cloud infrastructure to facilitate its use for a wider audience; and (iv) a cloud infrastructure allows a diverse group of researchers to collaborate effectively. The scientific findings will be extended during a follow-up event. Here, we present the applied workflows, initial results, and lessons learned from the hackathon.
Positive Orientation as a Predictor of Health Behavior during Chronic Diseases
Authors: Kupcewicz Ewa , Szypulska Anna , Doboszyńska Anna
Published: September 2019

Background: Positive orientation includes optimism, self-esteem, and life satisfaction. This research was conducted to determine whether positive orientation is an important predictor of health behaviors of patients with chronic movement disorders which require a rehabilitation program. Methods: The study involved 93 patients, including 46 women (49.5%) and 47 men (50.5%). The study utilized a standardized Positive Orientation Scale and a Health Behavior Inventory to measure the intensity of health-promoting behaviors. Results: The two variables of age and positive orientation were found to be predictors of overall healthy behavior, explaining a total of 22% variance of the dependent variable. Age was a predictor of preventative behavior (β = 0.37; R2 = 0.16). Its share in the prediction of this variable was significant (16%). The highest predictive value of positive mental attitude was having a positive orientation (β = 0.42; R2 = 0.17), which explained 17% of the variance of the dependent variable. However, age explained 14% of the variability of health practice results (β = 0.39; R2 = 0.14). Conclusion: The results of the research indicate the need to implement preventive programs with a positive orientation to modify the health behavior of chronically ill male and female patients.
Hydrochemistry and Dissolved Inorganic Carbon (DIC) Cycling in a Tropical Agricultural River, Mun River Basin, Northeast Thailand
Authors: Li Xiaoqiang , Han Guilin , Liu Man , Song Chao , Zhang Qian , Yang Kunhua , Liu Jinke
Published: September 2019

Dissolved inorganic carbon isotope composition (δ13CDIC), together with major ion concentrations were measured in the Mun River and its tributaries in March 2018 to constrain the origins and cycling of dissolved inorganic carbon. In the surface water samples, the DIC content ranged from 185 to 5897 μmol/L (average of 1376 μmol/L), and the δ13CDIC of surface water ranged from −19.6‰ to −2.7‰. In spite of the high variability in DIC concentrations and partial pressure of carbon dioxide (pCO2), the δ13CDIC values of the groundwater were relatively consistent, with a mean value of −16.9 ± 1.4‰ (n = 9). Spatial changes occurred in the direction and magnitude of CO2 flux through water-air interface (FCO2). In the dry season, fluxes varied from −6 to 1826 mmol/(m2·d) with an average of 240 mmol/(m2·d). In addition to the dominant control on hydrochemistry and dissolved inorganic carbon isotope composition by the rock weathering, the impacts from anthropogenic activities were also observed in the Mun River, especially higher DIC concentration of waste water from urban activities. These human disturbances may affect the accurate estimate contributions of carbon dioxide from tropical rivers to the atmospheric carbon budgets.
The JDCS Model and Blue-Collar Bullying: Decent Working Conditions for a Healthy Environment
Authors: Finstad Georgia Libera , Ariza-Montes Antonio , Giorgi Gabriele , Lecca Luigi Isaia , Arcangeli Giulio , Mucci Nicola
Published: September 2019

Violence in the workplace and its health consequences still represent one of the main obstacles to obtaining decent working conditions. In particular, blue-collar workers run a greater risk of experiencing episodes of violence, also because of a lack of autonomy and fewer social interactions. According to the work environment hypothesis, factors such as high workload, lack of social support and lack of job control represent the antecedents of workplace bullying. Following the job demand-control-support model (JDCS), violence can be the symptom of a high-strain environment. Moreover, it is still unclear if workplace bullying can mediate the effects of work-related stress on workers’ health outcomes. The aim of the present study is to analyse the relationship between the components of the JDCS and the health of the workers considering workplace bullying as a mediating variable. By a cross sectional study design, we tested the following theoretical hypotheses: first, JDCS components (conceptualized as stress) are supposed to significantly predict the level of workers’ health. Second, workplace bullying is supposed to mediate the relationship between the JDCS components and the level of health. The sample consists of 400 blue-collars from three different Italian companies. Work-related stress, health outcomes and workplace bullying were measured by specific self-administered questionnaires and the relationships between the variables of interest were tested through a structural equation model (SEM) analysis. The results showed that while the direct relationship between the components of the JDCS and the level of psychological health is weaker (standardized path coefficients SPC = 0.21), the partial mediation hypothesis shows that workplace bullying mediate the relationship between JDCS components and health outcomes (χ2/df ratio = 2.70; path from stress to workplace bullying SPC = 0.78; path from workplace bullying to general health SPC = 0.51; p = 0.01). The JDCS components (workload, lack of control, lack of support) are useful predictors for workplace bullying. On the other hand, bullying plays a mediating role between the stress experienced and the health consequences. The present study adds new insights into the relationship between violence seen as a form of social behavioural strain and the psychological health of workers. The theoretical and practical implications are discussed. Future research on blue-collars could use longitudinal designs in order to analyse the relationship between social environment, job design and strain reactions.
A Model of Phlebitis Associated with Peripheral Intravenous Catheters in Orthopedic Inpatients
Authors: Lee Sookhee , Kim Kyunghee , Kim Ji-Su
Published: September 2019

Phlebitis leads to increased discomfort for patients, longer hospital stays, and higher healthcare costs. This study aimed to identify predictive factors of peripheral phlebitis related to intravenous injection among orthopedic inpatients, develop a prediction model, and evaluate the goodness-of-fit of the prediction model. This study included 270 orthopedic patients who were hospitalized in the orthopedic ward of a general hospital. A peripheral intravenous injection-related questionnaire based on previous studies and the modified Infusion Nurses Society scale were used to collect data. Phlebitis risk factors were identified, and a prediction model was developed using the Bayesian regression model. Vein quality, contrast medium use, hygiene duration, and period of nursing clinical experience were significant based on their 95% confidence intervals. The prediction model exhibited good discrimination. The prediction model developed in this study can be used for screening high-risk patients for peripheral intravenous catheter-related phlebitis and for providing basic data for developing interventions for the prevention and management of peripheral intravenous catheter-related phlebitis.
Psychosocial Profile and Reproductive Decisions of Women Undergoing Pregnancy Termination for Medical Reasons—A Cross-Sectional Study
Authors: Zaręba Kornelia , La Rosa Valentina Lucia , Ciebiera Michał , Makara-Studzińska Marta , Gierus Jacek , Jakiel Grzegorz
Published: September 2019

Background: The study aims to define the profile of women who decide to exercise their right to terminate a pregnancy and their future reproductive plans. Methods: Patients found eligible for termination for medical reasons between 2014 and 2016 were asked to complete an anonymous survey consisting of sixty questions examining the determinants of the decision to terminate a pregnancy. In total, 150 completed surveys were returned (62.5%). Results: Environmental factors, such as age, education, place of residence, marital status and financial status did not affect the decision-making process. The majority of the respondents were females under 35 years of age (71.3%). In most cases, the pregnancies had been planned and long-awaited (62.7%). The study also indicated that 22.6% of the patients who had been against abortion changed their mind when they encountered problems themselves. In addition, 20% of them changed their views on the acceptability of abortion. Termination had an impact on the participants future reproductive plans. Eighteen percent of the patients said they were definitely not planning more pregnancies. The majority (84.09%) of these women said that the reason was the traumatic experiences related to their pregnancy. Conclusions: The personal experience of a pregnancy termination procedure changed women’s opinions about pregnancy termination and modified further reproductive plans.
Is It Possible to Become a Nurse in a Refugee Camp?
Authors: López-Entrambasaguas Olga María , Martínez-Linares Jose Manuel , Linares-Abad Manuel , Calero-García María José
Published: September 2019

The history of the Western Sahara has been marked by several events that have contributed to the protracted refugee situation in which the Sahrawi people have found themselves since 1975: the Spanish colonization and the subsequent decolonization process, the armed struggles between the indigenous population and the states of Morocco and Mauritania to occupy Western Saharan territory, assassinations and repression of the Sahrawi population, and the economic interests of external agents with regards to mineral resources. Twenty-five years ago, in the hostile environment of the Sahrawi refugee camps, a nursing school was founded. Essentially depending on foreign aid, this school has been responsible for training nursing professionals to meet the healthcare needs of the population. The aim of this paper is to provide an approach to the origin and evolution of nursing education for the Sahrawi refugee camps. The Sahrawi are the only refugee camps in the world to host such nursing schools.
Investigating the Current and Future Co-Occurrence of Ambrosia artemisiifolia and Ophraella communa in Europe through Ecological Modelling and Remote Sensing Data Analysis
Authors: Iannella Mattia , De Simone Walter , D’Alessandro Paola , Console Giulia , Biondi Maurizio
Published: September 2019

The common ragweed Ambrosia artemisiifolia has spread throughout Europe since the 1800s, infesting croplands and causing severe allergic reactions. Recently, the ragweed leaf beetle Ophraella communa was found in Italy and Switzerland; considering that it feeds primarily on A. artemisiifolia in its invaded ranges, some projects started biological control of this invasive plant through the adventive beetle. In this context of a ‘double’ invasion, we assessed the influence of climate change on the spread of these alien species through ecological niche modelling. Considering that A. artemisiifolia mainly lives in agricultural and urbanized areas, we refined the models using satellite remote-sensing data; we also assessed the co-occurrence of the two species in these patches. A. artemisiifolia is predicted to expand more than O. communa in the future, with the medium and high classes of suitability of the former increasing more than the latter, resulting in lower efficacy for O. communa to potentially control A. artemisiifolia in agricultural and urbanized patches. Although a future assessment was performed through the 2018 land-cover data, the predictions we propose are intended to be a starting point for future assessments, considering that the possibility of a shrinkage of target patches is unlikely to occur.
Child and Youth Health Literacy: A Conceptual Analysis and Proposed Target-Group-Centred Definition
Authors: Bröder Janine , Okan Orkan , Bollweg Torsten M. , Bruland Dirk , Pinheiro Paulo , Bauer Ullrich
Published: September 2019

(1) Background: This article adopts an interdisciplinary perspective to analyse, examine, and reflect upon prominent health literacy (HL) understandings in childhood and youth. (2) Method: The conceptual analysis combined Rodgers’ and Jabareen’s approaches to conceptual analysis in eight phases. (3) Results: First, we present exploratory entry points for developing a child-specific HL understanding based on the six dimensions of a ‘health-literacy 6D model’. Second, we describe and reflect upon five meta-level dimensions covering the HL definitions and models for children and youth found in the conceptual analysis. Third, we integrate our findings into a target-group-centred HL definition for children and youth. (4) Discussion/Conclusion: This article raises awareness for the heterogeneity of the current conceptual HL debate. It offers a multidisciplinary approach for advancing the existing understanding of HL. Four recommendations for future actions are deduced from the following four principles, which are inherent to the proposed target-group-centred HL definition: (a) to characterize HL from an asset-based perspective, (b) to consider HL as socially embedded and distributed, (c) to recognize that HL develops both in phases and in flexible ways, and (d) to consider the multimodal nature of health-related information. Further research is necessary to test the feasibility and applicability of the proposed definition and conceptual understanding in both research and practice.
Evaluation of Methicillin-Resistant Staphylococcus aureus Carriage and High Livestock Production Areas in North Carolina through Active Case Finding at a Tertiary Care Hospital
Authors: Feingold Beth J. , Augustino Kerri L. , Curriero Frank C. , Udani Paras C. , Ramsey Keith M.
Published: September 2019

Recent reports from the Netherlands document the emergence of novel multilocus sequence typing (MLST) types (e.g., ST-398) of methicillin-resistant Staphylococcus aureus (MRSA) in livestock, particularly swine. In Eastern North Carolina (NC), one of the densest pig farming areas in the United States, as many as 14% of MRSA isolates from active case finding in our medical center have no matches in a repetitive sequence-based polymerase chain reaction (rep-PCR) library. The current study was designed to determine if these non-matched MRSA (NM-MRSA) were geographically associated with exposure to pig farming in Eastern NC. While residential proximity to farm waste lagoons lacked association with NM-MRSA in a logistic regression model, a spatial cluster was identified in the county with highest pig density. Using MLST, we found a heterogeneous distribution of strain types comprising the NM-MRSA isolates from the most pig dense regions, including ST-5 and ST-398. Our study raises the warning that patients in Eastern NC harbor livestock associated MRSA strains are not easily identifiable by rep-PCR. Future MRSA studies in livestock dense areas in the U.S. should investigate further the role of pig–human interactions.
Hospitalization Services Utilization Between Permanent and Migrant Females in Underdeveloped Rural Regions and Contributing Factors—A Five-Time Data Collection and Analysis
Authors: Wen Xiaotong , Zheng Huilie , Feng Zhenyi , Tucker Winter , Lu Yuanan , Yuan Zhaokang
Published: September 2019

The proportion of migrating females has increased, and more often, old females are left in rural regions. Resources are needed to provide suitable hospitalization service to females in underdeveloped rural regions. Using multi-stage hierarchical cluster random sampling method, nine towns from three counties were enrolled in five-time points between 2006 and 2014 in this study. The research subjects of this study were females age 15 and up. Data regarding the utilization of inpatient services were collected and analyzed. Complex sampling logistic regression was conducted to analyze influencing factors. This study reveals that for both permanent females and migrant females, the older their age, the higher their hospitalization rate. The utilization of hospitalization service for permanent females was associated with the occurrence of chronic diseases (adjusted Odds Ratio (aOR) = 5.402). In addition, permanent females suffering from chronic diseases were more likely to avoid hospitalization despite their doctor’s advice (aOR = 34.657) or leave the hospital early against medical advice (AMA) (aOR = 10.009). Interventions to combat chronic diseases and adjust compensation schemes for permanent females need to be provided.
A Deterministic Model for Estimating Indoor Radon Concentrations in South Korea
Authors: Park Ji Hyun , Lee Cheol Min , Kang Dae Ryong
Published: September 2019

Estimating long-term exposure to indoor radon is necessary to determine the effects of indoor radon exposure on health. However, measuring long-term exposure to radon is labor intensive and costly. While developing models for estimating indoor radon concentrations are very difficult and unrealistic due to the many factors affecting radon concentrations, several studies have attempted to estimate indoor radon concentrations with mathematical models based on mass balance equations. However, these models are only applicable to specific regions or situations, and some require actual measurement data. This study sought to develop a widely applicable model for estimating mean annual indoor radon concentrations in actual residences considering seasonal variations in indoor radon. The model is based on a mass balance equation using data on geographical factors, building characteristics, meteorological factors, and nationwide radon surveys. The primary factor in our model is the infiltration factor, which can vary according to region, building materials, cracks, floor type, etc. In this study, infiltration factor was calculated according to the type of housing and groundwater usage, and the results thereof were applied to estimate indoor radon concentrations. Overall, measured concentrations and estimates of indoor radon concentrations using the infiltration factor were similar. This model showed better performance than our previous model, except for a few high concentration residences.
The Angle of Trunk Rotation in School Children: A Study from an Idiopathic Scoliosis Screening. Prevalence and Optimal Age Screening Value
Authors: Adamczewska Katarzyna , Wiernicka Marzena , Malchrowicz-Mośko Ewa , Małecka Joanna , Lewandowski Jacek
Published: September 2019

(1) Background: Idiopathic scoliosis is a deformity of the growing spine. It affects 2–3% of adolescents; yet its cause is still unknown. At the early stage of idiopathic scoliosis (IS), the signs are not very noticeable. That is why the primarily school-based screening for scoliosis is so important. (2) Methods: This was a cross-sectional analysis of 6850 respondents. Participants were elementary school students in the metropolitan area of Poland. The suspicion of IS was based on detection of three-dimensional deformity of the spine using scoliometer. (3) Results: Respondents were divided into two groups: Angle of trunk rotation (ATR) = 0–3º and ATR > 3º. Presented research using a referral criterion of 5º ATR showed that in the group of participants who had ATR > 3º the largest percentage of 5 degree values was recorded at the second and third measurement level of the spine (30.5%, 31.1%, respectively). Analyzing the differences between the two groups of girls (ATR = 0–3º, ATR > 3º), statistically significant differences were recorded between 9 and 11 years of age (p = 0.0388). Girls with ATR > 3º at all measuring levels are significantly slimmer than girls with ATR 0–3º; (4) Conclusions: Age; sex, and risk of developing angle of trunk rotation are very closely associated. The main thoracic (level 2) and thoraco-lumbar (level 3) level of measuring of the spine appears to be the most differentiating in the diagnosis of scoliosis. Girls with a lower degree of trunk deformity (4–6º trunk rotation), which can present mild scoliosis and those with a higher degree (7º trunk rotation) have lower body mass than girls within the norm.
Occupational Stress among Field Epidemiologists in Field Epidemiology Training Programs from the Public Health Sector
Authors: Ryu Sukhyun , Kim Young Woo , Kim Seowon , Liao Qiuyan , Cowling Benjamin J. , Lee Chang-Seop
Published: September 2019

Despite the high-demand work environment for field epidemiologists in field epidemiology training programs, little is known about their occupational stress. To identify occupational stress and its related factors, the occupational stress among trainees in field epidemiology training programs in Southeast Asia and Western Pacific regions from 2016 to 2018 was examined using six subscales: Role Overload, Role Insufficiency, Role Ambiguity, Role Boundary, Responsibility, and Physical Environment. Furthermore, the data on the year of training and type of training program as well as the level of burnout, which affects stress-coping strategies, were collected. Fisher’s exact tests and logistic regression models were used to examine associations between occupational stress, burnout, the number of years of training, and the type of training program. Sixty-two trainees participated, and there were no significant associations between burnout, the year of training, and type of training program. A burden of occupational stress in Role Overload and Physical Environment was reported by 56% and 53% of respondents, respectively. The trainees affiliated with a university program were less likely to have a burden of occupational stress in Responsibility and Physical Environment. It is concerning that more than half of trainees in the programs experienced occupational stress in Role Overload and Physical Environment. Additional efforts to design improved training programs to reduce occupational stress are warranted.
Incorporating Graph Attention and Recurrent Architectures for City-Wide Taxi Demand Prediction
Authors: Xu Ying , Li Dongsheng
Published: September 2019

Taxi demand prediction is one of the key factors in making online taxi hailing services more successful and more popular. Accurate taxi demand prediction can bring various advantages including, but not limited to, enhancing user experience, increasing taxi utilization, and optimizing traffic efficiency. However, the task is challenging because of complex spatial and temporal dependencies of taxi demand. In addition, relationships between non-adjacent regions are also critical for accurate taxi demand prediction, whereas they are largely ignored by existing approaches. To this end, we propose a novel graph and time-series learning model for city-wide taxi demand prediction in this paper. It has two main building blocks, the first one utilize a graph network with attention mechanism to effectively learn spatial dependencies of taxi demand in a broader perspective of the entire city, and the output at each time interval is then transferred to the second block. In the graph network, the edge is defined by an Origin–Destination relation to capture non-adjacent impacts. The second one uses a neural network which is adept with processing sequence data to capture the temporal correlations of city-wide taxi demand. Using a large, real-world dataset and three metrics, we conduct an extensive experimental study and find that our model outperforms state-of-the-art baselines by 9.3% in terms of the root-mean-square error.
Niacin Ameliorates Neuro-Inflammation in Parkinson’s Disease via GPR109A
Authors: Giri Banabihari , Belanger Kasey , Seamon Marissa , Bradley Eric , Purohit Sharad , Chong Raymond , Morgan John C. , Baban Babak , Wakade Chandramohan
Published: September 2019

In this study, we used macrophage RAW264.7 cells to elucidate the molecular mechanism underlying the anti-inflammatory actions of niacin. Anti-inflammatory actions of niacin and a possible role of its receptor GPR109A have been studied previously. However, the precise molecular mechanism of niacin’s action in reducing inflammation through GPR109A is unknown. Here we observed that niacin reduced the translocation of phosphorylated nuclear kappa B (p-NF-κB) induced by lipopolysaccharide (LPS) in the nucleus of RAW264.7 cells. The reduction in the nuclear translocation in turn decreased the expression of pro-inflammatory cytokines IL-1β, IL-6 in RAW264.7 cells. We observed a decrease in the nuclear translocation of p-NF-κB and the expression of inflammatory cytokines after knockdown of GPR109A in RAW264.7 cells. Our results suggest that these molecular actions of niacin are mediated via its receptor GPR109A (also known as HCAR2) by controlling the translocation of p-NF-κB to the nucleus. Overall, our findings suggest that niacin treatment may have potential in reducing inflammation by targeting GPR109A.
Zerumbone Suppresses Enterotoxigenic Bacteroides fragilis Infection-Induced Colonic Inflammation through Inhibition of NF-κΒ
Authors: Hwang Soonjae , Jo Minjeong , Hong Ju Eun , Park Chan Oh , Lee Chang Gun , Yun Miyong , Rhee Ki-Jong
Published: September 2019

Enterotoxigenic Bacteroides fragilis (ETBF) is human intestinal commensal bacterium and a potent initiator of colitis through secretion of the metalloprotease Bacteroides fragilis toxin (BFT). BFT induces cleavage of E-cadherin in colon cells, which subsequently leads to NF-κB activation. Zerumbone is a key component of the Zingiber zerumbet (L.) Smith plant and can exhibit anti-bacterial and anti-inflammatory effects. However, whether zerumbone has anti-inflammatory effects in ETBF-induced colitis remains unknown. The aim of this study was to determine the anti-inflammatory effect of orally administered zerumbone in a murine model of ETBF infection. Wild-type C57BL/6 mice were infected with ETBF and orally administered zerumbone (30 or 60 mg/kg) once a day for 7 days. Treatment of ETBF-infected mice with zerumbone prevented weight loss and splenomegaly and reduced colonic inflammation with decreased macrophage infiltration. Zerumbone treatment significantly decreased expression of IL-17A, TNF-α, KC, and inducible nitric oxide synthase (iNOS) in colonic tissues of ETBF-infected mice. In addition, serum levels of KC and nitrite was also diminished. Zerumbone-treated ETBF-infected mice also showed decreased NF-κB signaling in the colon. HT29/C1 colonic epithelial cells treated with zerumbone suppressed BFT-induced NF-κB signaling and IL-8 secretion. However, BFT-mediated E-cadherin cleavage was unaffected. Furthermore, zerumbone did not affect ETBF colonization in mice. In conclusion, zerumbone decreased ETBF-induced colitis through inhibition of NF-κB signaling.
Impact of Graphene-Based Surfaces on the Basic Biological Properties of Human Umbilical Cord Mesenchymal Stem Cells: Implications for Ex Vivo Cell Expansion Aimed at Tissue Repair
Authors: Jagiełło Joanna , Sekuła-Stryjewska Małgorzata , Noga Sylwia , Adamczyk Edyta , Dźwigońska Monika , Kurcz Magdalena , Kurp Katarzyna , Winkowska-Struzik Magdalena , Karnas Elżbieta , Boruczkowski Dariusz , Madeja Zbigniew , Lipińska Ludwika , Zuba-Surma Ewa K.
Published: September 2019

The potential therapeutic applications of mesenchymal stem/stromal cells (MSCs) and biomaterials have attracted a great amount of interest in the field of biomedical engineering. MSCs are multipotent adult stem cells characterized as cells with specific features, e.g., high differentiation potential, low immunogenicity, immunomodulatory properties, and efficient in vitro expansion ability. Human umbilical cord Wharton’s jelly-derived MSCs (hUC-MSCs) are a new, important cell type that may be used for therapeutic purposes, i.e., for autologous and allogeneic transplantations. To improve the therapeutic efficiency of hUC-MSCs, novel biomaterials have been considered for use as scaffolds dedicated to the propagation and differentiation of these cells. Nowadays, some of the most promising materials for tissue engineering include graphene and its derivatives such as graphene oxide (GO) and reduced graphene oxide (rGO). Due to their physicochemical properties, they can be easily modified with biomolecules, which enable their interaction with different types of cells, including MSCs. In this study, we demonstrate the impact of graphene-based substrates (GO, rGO) on the biological properties of hUC-MSCs. The size of the GO flakes and the reduction level of GO have been considered as important factors determining the most favorable surface for hUC-MSCs growth. The obtained results revealed that GO and rGO are suitable scaffolds for hUC-MSCs. hUC-MSCs cultured on: (i) a thin layer of GO and (ii) an rGO surface with a low reduction level demonstrated a viability and proliferation rate comparable to those estimated under standard culture conditions. Interestingly, cell culture on a highly reduced GO substrate resulted in a decreased hUC-MSCs proliferation rate and induced cell apoptosis. Moreover, our analysis demonstrated that hUC-MSCs cultured on all the tested GO and rGO scaffolds showed no alterations of their typical mesenchymal phenotype, regardless of the reduction level and size of the GO flakes. Thus, GO scaffolds and rGO scaffolds with a low reduction level exhibit potential applicability as novel, safe, and biocompatible materials for utilization in regenerative medicine.
Combinatorial Epigenetics Impact of Polyphenols and Phytochemicals in Cancer Prevention and Therapy
Authors: Arora Itika , Sharma Manvi , Tollefsbol Trygve O.
Published: September 2019

Polyphenols are potent micronutrients that can be found in large quantities in various food sources and spices. These compounds, also known as phenolics due to their phenolic structure, play a vital nutrient-based role in the prevention of various diseases such as diabetes, cardiovascular diseases, neurodegenerative diseases, liver disease, and cancers. However, the function of polyphenols in disease prevention and therapy depends on their dietary consumption and biological properties. According to American Cancer Society statistics, there will be an expected rise of 23.6 million new cancer cases by 2030. Due to the severity of the increased risk, it is important to evaluate various preventive measures associated with cancer. Relatively recently, numerous studies have indicated that various dietary polyphenols and phytochemicals possess properties of modifying epigenetic mechanisms that modulate gene expression resulting in regulation of cancer. These polyphenols and phytochemicals, when administrated in a dose-dependent and combinatorial-based manner, can have an enhanced effect on epigenetic changes, which play a crucial role in cancer prevention and therapy. Hence, this review will focus on the mechanisms of combined polyphenols and phytochemicals that can impact various epigenetic modifications such as DNA methylation and histone modifications as well as regulation of non-coding miRNAs expression for treatment and prevention of various types of cancer.
Key Topics in Molecular Docking for Drug Design
Authors: Torres Pedro H. M. , Sodero Ana C. R. , Jofily Paula , Silva-Jr Floriano P.
Published: September 2019

Molecular docking has been widely employed as a fast and inexpensive technique in the past decades, both in academic and industrial settings. Although this discipline has now had enough time to consolidate, many aspects remain challenging and there is still not a straightforward and accurate route to readily pinpoint true ligands among a set of molecules, nor to identify with precision the correct ligand conformation within the binding pocket of a given target molecule. Nevertheless, new approaches continue to be developed and the volume of published works grows at a rapid pace. In this review, we present an overview of the method and attempt to summarise recent developments regarding four main aspects of molecular docking approaches: (i) the available benchmarking sets, highlighting their advantages and caveats, (ii) the advances in consensus methods, (iii) recent algorithms and applications using fragment-based approaches, and (iv) the use of machine learning algorithms in molecular docking. These recent developments incrementally contribute to an increase in accuracy and are expected, given time, and together with advances in computing power and hardware capability, to eventually accomplish the full potential of this area.
Digyaindoleacid A: 2-(1-(4-Hydroxyphenyl)-3-oxobut-1-en-2-yloxy)-3-(1H-indol-3-yl)propanoic Acid, a Novel Indole Alkaloid
Authors: Kwain Samuel , Tetevi Gilbert , Mensah Thomas , Camas Anil , Camas Mustafa , Dofuor Aboagye , Azerigyik Faustus , Deng Hai , Jaspars Marcel , Kyeremeh Kwaku
Published: September 2019

Digyaindoleacid A (1) is one of the novel alkaloids produced by the Ghanaian Paenibacillus sp. DE2SH (GenBank Accession Number: MH091697) isolated from the mangrove rhizosphere soils of the Pterocarpus santalinoides tree growing in the wetlands of the Digya National Park, Brong Ahafo Region, Ghana. This compound was isolated on HPLC at tR ≈ 60 min and its structure determined by MS, 1D, and 2D-NMR data. When tested against Trypanosoma brucei subsp. brucei strain GUTat 3.1, 1 produced a half-maximal inhibitory concentration (IC50) 5.21 μM compared to the standard diminazene aceturate (IC50 = 1.86 μM). In the presence of normal mouse macrophages RAW 264.7, 1 displayed a higher selectivity towards T. brucei subsp. brucei (selectivity indices (SI) = 30.2) with low toxicity. This result is interesting given that the drug diminazene aceturate is considerably toxic and 1 is a natural product isolate. The structure of 1 incorporates the backbone of the amino acid tryptophan which is crucial in the metabolism of Trypanosoma brucei subsp. brucei strain GUTat 3.1. It is possible that 1, could interfere with the normal uptake and metabolism of tryptophan in the parasite. However, 1 (IC50 = 135.41 μM) produced weak antileishmanial activity when tested against Leishmania donovani (Laveran and Mesnil) Ross (D10).
Review of Thermophysical Property Data of Octadecane for Phase-Change Studies
Authors: Faden Moritz , Höhlein Stephan , Wanner Joschka , König-Haagen Andreas , Brüggemann Dieter
Published: September 2019

In this work we derive temperature-dependent functions for the most important material properties needed for phase change studies with octadecane. Over 80 references are reviewed in which at least one thermophysical property of octadecane is measured. The functions are valid ±40 K around the melting temperature and are surrounded by their confidence interval. It turns out that the values for the solid phase have much broader confidence intervals than the ones of the liquid phase. Hence, more accurate measurements are particularly desirable for the solid state material properties.
Ultra-Violet Electroluminescence of ZnO Nanorods/MEH-PPV Heterojunctions by Optimizing Their Thickness and Using AZO as a Transparent Conductive Electrode
Authors: Wageh S. , Zhao Su-Ling , Xie Xiao-Yi , Gao Song , Al-Ghamdi Ahmed
Published: September 2019

In this paper, a series of ITO/ZnO/ZnO nanorods/MEH-PPV/Al were prepared with different thicknesses of MEH-PPV that were changed from 15, 10 to 7 nm. The electric field in the devices was analyzed. An increase in the electric field on ZnO made hole injection easy and the electrons tunnel fast through thinner MEH-PPV to ZnO. This made the carriers prefer to recombine inside the ZnO layer, and the emission of ZnO was predominant under direct current (DC) bias. Furthermore, another device was fabricated with the structure of AZO (Al-doped ZnO)/ZnO/ZnO nanorods/MEH-PPV/Al. Ultra-violet (UV) electroluminescence (EL) at 387 nm from ZnO band edge emission was realized under DC bias. The turn-on voltage of the devices having AZO as the electrode is lower than that of ITO, and the EL power is enhanced. This work also studies the effect of inserting LiF underneath the Al electrode and above the layer of MEH-PPV. The LiF film inserted caused an obvious decrease in turn-on voltage of the devices and a pronounced increase in the EL power. The mechanism of electroluminescence enhancement is also discussed.
An Experimental and Numerical Study of Repairs on Composite Substrates with Composite and Aluminum Doublers Using Riveted, Bonded, and Hybrid Joints
Authors: Pitta Siddharth , Roure Francesc , Crespo Daniel , Rojas Jose I.
Published: September 2019

In this work, experimental and numerical analyses of repairs on carbon fiber reinforced epoxy (CFRE) substrates, with CFRE and aluminum alloy doublers typical of aircraft structures, are presented. The substrates have a bridge gap of 12.7 mm (simulated crack), repaired with twin doublers joined with riveted, adhesive bonded, and hybrid joints. The performance of the repairs using different doubler materials and joining techniques are compared under static loading. The experimental results show that riveted joints have the lowest strength, while adhesive bonded joints have the highest strength, irrespective of the doubler material. Finite element analysis (FEA) of the studied joints is also performed using commercial FEA tool Abaqus. In the FEA model, point-based fasteners are used for the rivets, and a cohesive zone contact model is used to simulate the adhesive bond. The FEA results indicate that the riveted joints have higher tensile stresses on the metal doublers compared to the composite doublers. As per the failure modes, interestingly, for hybrid joints using composite doublers, the doublers fail due to net-section failure, while, for hybrid joints using metal doublers, it is the composite substrate that fails due to net-section failure. This suggests vulnerability of the composite structures to mechanical fastener holes. Lastly, the Autodesk Helius composite tool is used for prediction of first-ply failure and ply load distribution, and for progressive failure analysis of the composite substrate.
Complete Stress–Strain Curves of Self-Compacting Steel Fiber Reinforced Expanded-Shale Lightweight Concrete under Uniaxial Compression
Authors: Zhao Mingshuang , Zhang Bingxin , Shang Pengran , Fu Yan , Zhang Xiaoyan , Zhao Shunbo
Published: September 2019

To expand the structural application of steel fiber reinforced expanded-shale lightweight concrete (SFRELC), a self-compacting SFRELC with high-workability was developed based on previous research. As part of the investigation, the present study focuses on the adaptability of formulas used for the complete stress–strain curves of steel fiber reinforced lightweight-aggregate concrete and conventional concrete under uniaxial compression. On the basis of mix proportion of SFRELC, self-compacting SFRELC was designed with the volume fraction of steel fiber as 0%, 0.4%, 0.8%, 1.2%, 1.6%, and 2.0%. Eighteen cylindrical specimens with dimensions of Φ150 mm × 300 mm were tested to measure the uniaxial compressive stress–strain curves of self-compacting SFRELC. Results indicated that, with the increasing volume fraction of steel fiber, the compressive strain at the peak-stress of the stress–strain curve increased, while the slope of the descending portion decreased. This increased the energy absorption of self-compacting SFRELC with a higher compression toughness. With a comparison of test results between four groups of calculation models, a group of formulas is selected to express the complete stress–strain curves of self-compacting SFRELC under uniaxial compression.