bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local heat‐shock mediated multi‐color labeling visualizing behaviors of enteric neural crest cells associated with division and neurogenesis in zebrafish gut
Authors: Kuwata Mai , Nikaido Masataka , Hatta Kohei 
Published: April 2019

AbstractBackgroundThe enteric nervous system (ENS) is derived from enteric neural crest cells (ENCCs) that migrate into the gut. The zebrafish larva is a good model to study ENCC development due to its simplicity and transparency. However, little is known how individual ENCCs divide and become neurons.ResultsHere, by applying our new method of local heat‐shock mediated Cre‐recombination around the dorsal vagal area of zebrafish embryos we produced multicolored clones of ENCCs, and performed in vivo time‐lapse imaging from ca. 3.5 to 4 days post‐fertilization after arrival of ENCCs in the gut. Individual ENCCs migrated in various directions and were highly intermingled. The cell divisions were not restricted to a specific position in the gut. Antibody staining after imaging with anti‐HuC/D and anti‐Sox10 showed that an ENCC produced two neurons, or formed a neuron and an additional ENCC that further divided. At division, the daughter cells immediately separated. Afterward, some made soma‐soma contact with other ENCCs.ConclusionsWe introduced a new method of visualizing individual ENCCs in the zebrafish gut, describing their behaviors associated with cell division, providing a foundation to study the mechanism of proliferation and neurogenesis in the ENS in vertebrates.
Symbiotic endolithic microbes alter host morphology and reduce host vulnerability to high environmental temperatures
Authors: Gehman Alyssa‐Lois M. , Harley Christopher D. G. 
Published: April 2019

AbstractThermal stresses, such as those associated with global warming, have the potential to change the strength and even the direction of interspecific interactions. On rocky shores, bio‐eroding microbial endoliths infect the mussel Mytilus californianus. Infestation by microbial endoliths can weaken the shell and lead to mechanical failure and death, increased vulnerability to predation, mechanical damage, etc. However, endolith infestation is associated with the loss of the dark‐colored periostracum, exposing the underlying light gray prismatic layer of the shell and potentially reducing stressful heat gain during low tide. We explore the consequences of the mussel–endolith relationship on mussel tolerance to high environmental temperature through a series of experimental manipulations and comparative observations. Experimental sterilization of the shell surface reduces the rate of periostracum loss, suggesting that the change in shell surface color is indeed caused by microbes residing on/in the shell. Eroded shells absorbed less solar energy than shells with their periostracum intact, and mussel mimics with infested shells remained cooler on sunny days. Manipulation of shell color in the field resulted in higher mortality in black‐painted mussels relative to gray‐painted or naturally eroded mussels. Furthermore, following exceedingly hot weather, mortality was significantly lower for heavily infested, light‐colored mussels than for lightly infested, dark‐colored mussels. Thus, although shell‐boring microbes have the potential to act as parasites under the majority of conditions experienced by mussels, they may be critical mutualists during periods of intense thermal stress. This context‐dependent symbiosis may allow mussels to occupy higher shore levels than would otherwise be possible, and thus indirectly benefit the hundreds of species which use mussel beds as habitat.
Synergistic flame‐retarded effect between carbon nanotubes and ammonium polyphosphate in Nylon6 and Nylon6/polystyrene blends
Authors: Zhang Shuai , Lu Chang , Gao Xi‐ping , Huang Xin‐hui , Cao Cheng‐lin , Yao Da‐hu 
Published: April 2019

SummaryThe association of carbon nanotubes (CNTs) and ammonium polyphosphate (APP) as flame retardants was utilized for improving the flame retardancy of nylon6 (PA6) and blends of PA6/Polystyrene (PS). A remarkable synergistic effect between APP and CNTs was observed in PA6 at 1‐wt% CNTs loading. Rheological tests showed that 1‐wt% CNTs formed a network structure. Morphology of residue char indicated that a network enhanced synergistic effect. A synergy between APP and CNTs in blends of PA6/PS (56/24) was also investigated. APP and CNTs exhibited a remarkable synergistic effect at 0.25‐wt% CNTs loading, but the antagonistic effect on flame retardancy of blends was observed at 1‐wt% CNTs loading. Transmission electron microscopy showed that CNTs were exclusively dispersed in the PA6 phase of blends. The selective dispersion of CNTs caused the formation of a network at 0.25‐wt% CNTs loading. Morphology of residue char indicated that 0.25‐wt% CNTs were benefited by the formation of a continuous and well‐swollen residue char that enhanced the synergistic effect in blends. However, the aggregation of 1‐wt% CNTs in PA6 phase caused high viscosity of PA6 phase, resulting in a poor expansion of the residue char. Consequently, the antagonism was exhibited.
Generalized analysis of regional fire risk using data visualization of incidents
Authors: Liu Dingli , Xu Zhisheng , Fan Chuangang 
Published: April 2019

SummaryFire has been a worldwide disaster, and it is important to analyze regional fire risk for better fire prevention. Regional fire risk can be generally analyzed by using data visualization of fire incidents. A dataset of 20 622 fire incidents in Changsha City of China from 2011 to 2017 was processed and filtered as the origin risk points. Then, a generalized risk model (GRM) was established for calculating fire risk values of anywhere in Changsha. By using JavaScript and HTML5, the generalized fire risk graphics were drawn based on mapping different fire risk values with different colors. For visualizing fire incidents, the inner and outer generalization radiuses of the origin risk point were set to be 1 (110 m) and 10 (1100 m), respectively. It was found that the high and medium fire risk areas were mainly distributed in urban areas and market towns, especially in central city. The spatial distribution characteristics of fire risk of different time ranges and different causes were significantly varied. The results can provide guidance of fire prevention for the fire department in Changsha. Other cities' regional fire risk and even other types of disaster risk can also be generally analyzed using GRM.
Study on the smoke back‐layering and critical ventilation in the road tunnel fire at high altitude
Authors: Zhang Shaogang , Wang Jinhui , He Kun , Yao Yongzheng , Peng Min 
Published: April 2019

SummaryA series of numerical simulations were conducted in order to investigate the characteristics of smoke back‐layering and critical ventilation in the road tunnel at high altitude with reduced ambient atmospheric pressures. The results indicated that the smoke back‐layering length decreases with the reduction of ambient pressure. Meanwhile, the dimensionless critical longitudinal ventilation velocity decreases with one‐third power of the factor of ambient pressure at high altitude. By modifying the traditional dimensionless fire heat release rate with ambient pressure, new models were deduced to predict the smoke back‐layering length and critical ventilation velocity in the road tunnel at high altitude.
The effect of target function on the predictive performance of the two‐stage ridge estimator
Authors: Toker Selma , Özbay Nimet 
Published: April 2019

AbstractThe main thrust of this study is to consider the problem of simultaneous prediction of actual and average values of the simultaneous equations model through the target function of Shalabh (Bulletin of International Statistical Institute, 1995, 56, 1375–1390). We focus on the predictive performance of the two‐stage ridge estimator with the motivation for eliminating the disorder arising from multicollinearity. An optimal biasing parameter of the two‐stage ridge estimator is derived by a minimization process of prediction mean square error. In addition, an optimal estimator for the weight of observed value in target function is attained theoretically. The results inferred from a numerical example and a Monte Carlo experiment provide a dramatic improvement in the predictive ability of the two‐stage ridge estimator.
RelB controls adaptive responses of astrocytes during sterile inflammation
Authors: Gupta Angela S. , Waters Michael R. , Biswas Debolina D. , Brown Lashardai N. , Surace Michael J. , Floros Constantinos , Siebenlist Ulrich , Kordula Tomasz 
Published: April 2019

AbstractIn response to brain injury or infections, astrocytes become reactive, undergo striking morphological and functional changes, and secrete and respond to a spectrum of inflammatory mediators. We asked whether reactive astrocytes also display adaptive responses during sterile IL‐1β‐induced neuroinflammation, which may limit tissue injury associated with many disorders of the central nervous system. We found that astrocytes display days‐to‐weeks long specific tolerance of cytokine genes, which is coordinated by NF‐κB family member, RelB. However, in contrast to innate immune cells, astrocytic tolerance does not involve epigenetic silencing of the cytokine genes. Establishment of tolerance depends on persistent higher levels of RelB in tolerant astrocytes and its phosphorylation on serine 472. Mechanistically, this phosphorylation prevents efficient removal of RelB from cytokine promoters by IκBα and helps to establish tolerance. Importantly, ablation of RelB from astrocytes in mice abolishes tolerance during experimental neuroinflammation in vivo.
The effect of parathyroidectomy on patients' symptoms in tertiary hyperparathyroidism
Authors: See Anna , Lim Amy E. L. , Wong Jiunn , Choong Hui Lin , Iyer N Gopalakrishna , Tan Hiang Khoon , Tan Ngian Chye , Ng Jeremy C. F. 
Published: April 2019

AbstractBackgroundThe efficacy of parathyroidectomy for primary and secondary hyperparathyroidism is well‐established but evidence in tertiary hyperparathyroidism is lacking. We examined parathyroidectomy's effect in tertiary hyperparathyroidism.MethodsPatients with tertiary hyperparathyroidism who underwent parathyroidectomy were followed up for 12 months. A modification of the 13‐item parathyroid symptoms list developed by Pasieka was administered at 0, 1, 3, 6, and 12 months post‐surgery. We also examined if preoperative factors would predict symptom improvement post‐surgery.ResultsNinety‐one patients were included. Survey response rates at 1, 3, 6, and 12 months post‐surgery were 97.8%, 90.1%, 82.4%, and 80.2%, respectively. Mean preoperative Pasieka parathyroid score (PSS) was 6.3 ± 2.7. At first month, PSS decreased to 2.9 ± 2.0 (P < .001) and was sustained at 3, 6, and 12 months (2.7 ± 2.1, P < .001, 2.3 ± 1.6, P < .001 and 3.4 ± 2.5, P < .001). The degree of PSS reduction at 1‐month post‐parathyroidectomy correlated strongly with preoperative symptom severity (Pearson's coefficient: 0.690, P < .001).ConclusionsParathyroid symptoms unequivocally improve post‐parathyroidectomy. The greatest degree of improvement was observed in early postoperative period up to 6 months.
Design strategies for two‐dimensional material photodetectors to enhance device performance
Authors: Wang Jun , Han Jiayue , Chen Xiaoqing , Wang Xinran 
Published: April 2019

AbstractTwo‐dimensional (2D) materials are intensively attractive for fabricating high sensitive photodetectors in terms of atomically thin flexible and ultrafast charge transport feature. Due to their atomically thin body, designing high performance detector requires new physical mechanisms and device structures. In this review, we classify design strategies and device structures into four categories depending on their physical mechanisms (photovoltaic effect, photoconductive effect, photothermoelectric effect or photobolometric effect, and surface plasma‐ wave‐assisted effect), and summarize the device performances. Finally, future prospects and development direction for 2D material photodetectors are described. Those design strategies descriptions about photoelectronic detector provide a reference for high responsivity and fast response speed photodetector at broadband sensing in the future.
The toxic potential of a fourth‐generation E‐cigarette on human lung cell lines and tissue explants
Authors: Rankin Gregory D. , Wingfors Håkan , Uski Oskari , Hedman Linnéa , Ekstrand‐Hammarström Barbro , Bosson Jenny , Lundbäck Magnus 
Published: April 2019

AbstractThe use of electronic cigarettes (E‐cigs) is rapidly increasing. The latest generation of E‐cigs is highly customizable, allowing for high heating coil temperatures. The aim of this study was to assess the toxic potential of a fourth‐generation E‐cig. Aerosols generated from E‐liquid with (24 mg/mL) and without nicotine, using a fourth‐generation E‐cig, were chemically analysed and compared with cigarette smoke (K3R4F). Human lung epithelial cell lines and distal lung tissue explants were exposed to E‐cig vapour extract (EVE) and cigarette smoke extract for 24 hours and assessed for viability, inflammation, oxidative stress and genotoxicity. E‐cig aerosols contained measurable levels of volatile organic compounds, aldehydes and polycyclic aromatic hydrocarbons, in general, to a much lesser extent than cigarette smoke. Higher levels of certain carbonyls, e.g. formaldehyde, were detected in the E‐cig aerosols. EVEs decreased cell viability of BEAS‐2B cells, whereas little effect was seen in A549 cells and distal lung tissue. The nicotine‐containing EVE caused a greater decrease in cell viability and significant increase in DNA damage than the nicotine‐free EVE. Increased cytotoxicity, reactive oxygen species production and genotoxicity were seen with cells and tissue exposed to cigarette smoke extract compared with EVEs. Although E‐cig aerosols were less toxic than cigarette smoke, it was not benign. Moreover, the EVE containing nicotine was more toxic than the nicotine‐free EVE. More research is needed on the short‐ and long‐term health effects of vaping and the usage of newly emerging E‐cig devices to evaluate better the potential negative effects of E‐cigs on human health.
Is normalized hindlimb length measurement in assessment of thyroid disruption in the amphibian metamorphosis assay relevant?
Authors: Pawlowski Sascha , Dammann Martina , Weltje Lennart , Champ Samantha , Mathis Michael , Fort Douglas J. 
Published: April 2019

AbstractThe amphibian metamorphosis assay represents an OECD Level 3 and EDSP Tier 1 ecotoxicity test assessing thyroid activity of chemicals in African clawed frog (Xenopus laevis). To evaluate the effectiveness of snout‐vent length (SVL) normalization of hindlimb length (HLL), correlation between the HLL and SVL or body weight was evaluated in the control groups of 10 individual studies from three laboratories. Two studies required separate analysis of the Nieuwkoop‐Faber (NF) stage ≤60 and >60 animals creating a total of 12 data sets. On study day 7, significant positive correlation between HLL and SVL or body weight was observed in eight and seven of the 10 data sets, respectively (r = 0.608‐0.843 and 0.583‐0.876). On study day 21, significant positive correlation between HLL and SVL or body weight was found in three and four of the 12 data sets, respectively (r = 0.452, 0.480 and 0.553 and r = 0.621, 0.546, 0.564 and 0.378). Significant positive correlation between HLL and SVL was found in three of five studies, including ≤NF stage 60 data (r = 0.564, 0.546 and 0.621). In one of eight studies, including >NF stage 60 data, the positive correlation between HLL and body weight was determined (r = 0.378). Negative or no correlation between HLL and SVL or body weight was found in the other late stage data sets. Therefore, use of SVL‐normalized HLL to assess thyroid‐mediated effects in X. laevis tadpoles is not warranted. HL stage relative to body stage should be considered.
Fibrin hydrogel as a scaffold for differentiation of induced pluripotent stem cells into oligodendrocytes
Authors: Nazari Bahareh , Kazemi Mansure , Kamyab Ahmadreza , Nazari Banafsheh , Ebrahimi‐Barough Somayeh , Hadjighassem Mahmoudreza , Norouzi‐Javidan Abbas , Ai Arman , Ahmadi Akbar , Ai Jafar 
Published: April 2019

AbstractThe importance of tissue engineering has been established as a promising approach in treating neurodegenerative diseases. The purpose of the current study is to determine the effect of fibrin hydrogel on the differentiation of iPSC into oligodendrocyte. For this purpose, iPSCs transduced by miR‐338 expressing lentiviruses. They were treated with basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and platelet‐derived growth factor (PDGF)‐AA. The process was traced by a 6‐day treatment in a mitogen‐free medium. At the end of the process, multipolar preoligodendrocytes appeared. In comparison to tissue culture plate (TCP), MTT assay demonstrated a significant increase in the viability of cells cultured in fibrin hydrogel. SEM analysis showed cells with elongated morphology and intertwined intercellular interactions. An immunofluorescent assay confirmed the expression of oligodendrocyte markers Olig2 and O4. In comparison to TCP, real‐time PCR data indicated a significant increase in the expression of some markers such as Olig2, MBP, Sox10, and PDGFRα on cells encapsulated in fibrin hydrogel. Overall, the results suggest that fibrin hydrogel improves viability of cells and promotes the differentiation of iPSCs into preoligodendrocytes. Hence, it can be used as an appropriate option in the tissue engineering in order to treat neurodegenerative diseases. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:192–200, 2020.
Chalcopyrite bioleaching in the presence of high chloride concentrations
Authors: Martins Flávio L , Patto Guilherme B , Leão Versiane A 
Published: April 2019

AbstractBackgroundDissolution of chalcopyrite is one of the most important challenges in hydrometallurgy because it is very difficult to leach due to the passivation of its surface, whose nature is still controversial. The addition of chloride ions can catalyse copper dissolution, but when it comes to bioleaching, chloride usually cannot be applied because of its toxicity to most bioleaching bacteria.ResultsThe current work investigated, for the first time, chalcopyrite bioleaching with Sulfolobus acidocaldarius at high concentrations of chloride [up to 1.0 mol L−1 sodium chloride (NaCl)] and 67.5 °C. Copper dissolution attained 100% within 14 days in the presence of microorganisms, while only 55% was observed in the abiotic test; both tests were carried out with 1.0 mol L−1 NaCl. Raman spectroscopy of the leached chalcopyrite with S. acidocaldarius and 1.0 mol L−1 NaCl revealed the presence of elemental sulphur as a reaction product on the fifth day of the experiment; jarosite was also detected after 14 days in the same test.ConclusionBecause of the low ability of the archaea to oxidize ferrous ion, the redox potential of the biotic test, having 1.0 mol L−1 of chloride, remained most of the time in the range 350–420 mV, in which the leaching rate of chalcopyrite was the highest. © 2019 Society of Chemical Industry
Retest and treat: a review of national HIV retesting guidelines to inform elimination of mother‐to‐child HIV transmission (EMTCT) efforts
Authors: Drake Alison L , Thomson Kerry A , Quinn Caitlin , Newman Owiredu Morkor , Nuwagira Innocent B , Chitembo Lastone , Essajee Shaffiq , Baggaley Rachel , Johnson Cheryl C 
Published: April 2019

AbstractIntroductionHigh maternal HIV incidence contributes substantially to mother‐to‐child HIV transmission (MTCT) in some settings. Since 2006, HIV retesting during the third trimester and breastfeeding has been recommended by the World Health Organization in higher prevalence (≥5%) settings to reduce MTCT. However, many countries lack clarity on when and how often to retest pregnant and postpartum women to optimize resources and service delivery. We reviewed and characterized national guidelines on maternal retesting based on timing and frequency.MethodsWe identified 52 countries to represent variations in HIV prevalence, geography, and MTCT priority and searched available national MTCT, HIV testing and HIV treatment policies published between 2007 and 2017 for recommendations on retesting during pregnancy, labour/delivery and postpartum. Recommended retesting frequency and timing was extracted. Country HIV prevalence was classified as: very low (<1%), low (1% to 5%), intermediate (>5 to <15%) and high (≥15%). Women with unknown HIV status at delivery/postpartum were included in retesting guidelines.Results and discussionOverall, policies from 49 countries were identified; 51% from 2015 or later and most (n = 25) were from Africa. Four countries were high HIV prevalence, seven intermediate, sixteen low and twenty‐two very low. Most (n = 31) had guidance on universal voluntary opt‐out HIV testing at the first antenatal care (ANC) visit. Beyond the first ANC visit, the majority (78%, n = 38) had guidance on retesting; 22 recommended retesting all women with unknown/negative status, five only if unknown HIV status, three in pregnancy based on risk and eight combining these approaches. Retesting was universally recommended during pregnancy, labour/delivery, and postpartum for all high prevalence settings and four of seven intermediate prevalence settings. Five UNAIDS priority countries for EMTCT with low/very low HIV prevalence, but high/intermediate MTCT, had no guidance on retesting.ConclusionsRetesting guidelines for pregnant and postpartum women were ubiquitous in high prevalence countries and defined in some intermediate prevalence countries, but absent in some low HIV prevalence countries with high MTCT. Countries may require additional guidance on how to optimize maternal HIV testing and whether to prioritize retesting efforts or discontinue universal retesting based on HIV incidence. Research is needed to assess country‐level guideline implementation and impact.
Orphans and Pro‐social Behaviour: Evidence from Uganda
Authors: McCannon Bryan C. , Rodriguez Zachary 
Published: April 2019

AbstractDisease and violence escalates the prevalence of orphanhood. We investigate whether individuals who were orphaned as a child suffer long‐term consequences on their pro‐sociality. We conduct a lab‐in‐the‐field experiment in rural Uganda where, among other contributing factors, the HIV/AIDS pandemic hit hardest. Subjects made decisions to contribute to a public good. Results indicate that adults who were orphaned as a child contribute less. We provide evidence that an important channel through which the mechanism operates is through social norms. Subjects orphaned tend to have lower expectations regarding typical behaviour of others. A strong interaction effect is identified where those with the lowest expectations who were also orphaned contribute the least to the public good. Thus, we document orphanhood's long‐term consequences to a community. © 2019 John Wiley & Sons, Ltd.