bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic study of efficient nanocomposites {Ni0.5 Zn0.5−x Cex -oxides electrodes} for natural gas-fed fuel cells
Authors: Tayyab Zuhra , Rehman Saif Ur , Shakir Imran , Khan M Ajmal , Mushtaq Naveed , Alvi Farah , Rauf Sajid , Khan Aqsa , Fatima Mahin , Raza Rizwan 
Published: December 2019

Abstract
Highly catalytic active anode materials are one of the scorching zones in recent solid oxide fuel cells (SOFCs). In order to develop high performance SOFCs compatible anode materials are extremely required. In this work, Ni0.5Zn0.5−xCex-oxides (NZC-oxide) nanocomposite anode material is synthesized by employing facile, low cost wet chemical technique. The phase structure before and after CH4 environment is studied by x-ray diffraction (XRD) and Raman spectroscopy. However, no significant structural phase change is observed in Ni0.5Zn0.3Ce0.2-oxides after CH4 treatment. Additional characterizations are investigated by UV-visible spectroscopy, Fourier transform infrared spectroscopy and Scanning electron microscopy (SEM). The dc electrical conductivities are measure by four probe method. The ideal and suitable Ni0.5 Zn0.3Ce0.2-oxides among all nanocomposites using as anode in fuel cell devices, show maximum power density of 500 mWcm−2 with open circuit voltage (OCV) of 1.0 V at 600 °C. By empowering enhanced catalytic assets of Ni0.5 Zn0.3Ce0.2-oxides nanocomposite anode may be useful for fuel cell applications.
Study of corrosion mechanism of cast iron in molten aluminum
Authors: Wang Qiyu , yang Hui , Li Xiaohong , Zhang Guodong 
Published: December 2019

Abstract
The corrosion mechanism of three aluminum ingot mold materials used by Chinese aluminum electrolytic enterprises in molten aluminum was studied: The three materials are pearlite cast iron(PCI) contains vermicular graphite, lamellar graphite, and spherical graphite respectively. After 800 °C molten aluminum corrosion for 4 h, the intermetallic compound (IMC) layers of Fe2Al5 and FeAl3 is formed at the interface. It was found that the volume of spherical graphite in IMC was reduced to 20%, and lamellar graphite aggregated in the IMC layer. The average thickness of the Fe2Al5 layer in PCI1, PCI2 and PCI3 is about 180 μm, 100 μm and 101 μm, respectively. The weight loss rate of PCI1 is 2.57 (mg cm−2)min−1, PCI2 is 2.20 (mg cm−2)min−1, and PCI3 is 2.24(mg cm−2)min−1. There are dispersed Cr and Mo carbides in the IMC layer. Si-rich ribbon-shaped region was found at the interface between cast iron and IMC. The needle-like precipitates (Al4C3) were observed only at the only at the boundary between cast iron and IMC in PCI1.
Optical graphene quantum dots gas sensors: experimental study
Authors: Raeyani D , Shojaei S , Ahmadi-Kandjani S 
Published: December 2019

Abstract
We present a room temperature Graphene Quantum Dots (GQDs) based optical gas sensor for carbon dioxide gas detection. GQDs were prepared by a hydrothermal method and deposited on a quartz substrate using a drop-casting technique. The size of synthesized GQDs is in the range of 10 to 20 nm. GQDs films were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), photoluminescence (PL) and UV-Vis absorption spectroscopy. The gas sensing measurements were studied using optical absorbance changes of GQDs film upon exposure to different concentrations of CO2 gas. The as-prepared gas sensor showed a significant sensitivity with a partially reversible response to CO2 gas, indicating its great potential to pave a way toward a novel CO2 gas sensor.
Surface functionalization of porous chitosan microsphere with silver nanoparticle and carbon dot
Authors: Ghosh Dastidar Debabrata , Saha Sourabh , Dutta Gourango , Abat Swati , Guha Nilayan , Ghosh Dipanjan 
Published: December 2019

Abstract
Porous microspheres have enormous specific surface area due to the presence of micropores. This makes them suitable for all applications that involves surface adsorption e.g. chromatographic separation of biomolecules, catalytic reactions and drug delivery. The surface property may further be tuned up by functionalization of microsphere surface with different nanoparticles like silver nanoparticle and carbon dot (CD). In this study porous chitosan microsphere (PCM) was synthesized by ‘phase inversion of emulsion’ technique. Silver nanoparticle (AgNP) was synthesized, insitu during the process of surface modification, using silver nitrate solution. CD was synthesized by solvothermal method using urea and EDTA. PCM, AgNP and CD were of ∼9 μm, ∼27 nm and ∼14 nm diameter, respectively. From FTIR study it was confirmed that the amino group of chitosan backbone was responsible for reduction of Ag+ ion to Ag° species which were clustered as AgNP and attached to the surface of PCM. The same amino group of chitosan molecule was also responsible for conjugation of CD to the microparticle surface. The optimized AgNP functionalized PCM had 5.36 × 1011 AgNP per mg dried mass. The release of AgNP was triggered at pH ≤ 4.5. The CD functionalized PCM had 56.82 ± 2.8 % conjugation efficiency and 7.83 ± 1.7 % quantum yield with respect to quinine sulphate.
Effect of solvent on the energy storage property of poly(vinylidene fluoride-hexafluoropropylene)
Authors: Chen Fujia , Zhao Yuetao , Zhou Yujiu , Xu Jianhua , Yang Yajie , Yang Wenyao 
Published: December 2019

Abstract
The application prospects of dielectric materials such as poly(vinylidene fluoride) (PVDF) based polymers in the field of energy storage have stimulated extensive research. In this study, the energy storage characteristics of poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP)) films crystallized from several solvents with different vapor pressure were investigated. The charge-discharge efficiency of the P (VDF-HFP) film crystallized from N, N-dimethylformamide (DMF) demonstrates an efficiency of 85% under an electric field of 1000 kV cm−1, which is 1.42 times of the film crystallized from dimethyl sulfoxide (DMSO). Meanwhile, the insulation resistivity of the film crystallized from DMF is also higher than other films, and the energy storage characteristics are optimal in this study. This work provides guidance for the preparation of PVDF-based polymer films using the solution method.
Microstructure, corrosion behavior and mechanical properties of a non-isothermal ageing treated cast Al–4.5Cu–3.5Zn–0.5Mg alloy
Authors: Wang Haisheng , Jiang Bo , Yi Danqing , Wang Bin , Liu Huiqun , Wu Chunping , Shen Fanghua 
Published: December 2019

Abstract
Al–Cu, being a high-strength aluminium alloy, is used to prepared castings which are widely used in the automotive and aerospace industries as lightweight parts. However, corrosion is an issue. The Al–Cu alloys show improved properties when other elements are added to them. One such alloy is Al–4.5Cu–3.5Zn–0.5Mg. In order to improve the corrosion resistance and strength of this Al–4.5Cu–3.5Zn–0.5Mg cast alloy, a novel non-isothermal ageing (NIA) treatment was developed that comprised a heating stage up to 250 °C, followed by a cooling stage down to room temperature at the rate of 60 °C·h−1. Specimens were removed throughout the process and immediately quenched for morphological, mechanical, and electrochemical testing. The hardness continuously increased up to 124 HV with ageing time. The alloy exhibited optimal properties after ageing for ~340 min (with the aging temperature reaching 130 °C during the cooling stage of the NIA treatment), with a tensile strength and maximum corrosion depth of 395 MPa and 165 μm, respectively. Fine precipitates discontinuously appeared at the grain boundaries during the cooling stage. Some new fine Ω phases were precipitated in the grains, thereby narrowing the precipitation-free zone. Thus, high strength and good corrosion resistance of the alloy can be obtained via the NIA treatment. Notably, NIA treatments are less time-consuming than isothermal ageing treatments, thereby expanding the applications of high-strength cast aluminium alloys in the manufacturing industry.
A facile hydrothermal synthesis and properties of TiO2 nanosheet array films
Authors: Lai Liuyuan , Lei E , Hu Chaoyang , Zhao Dan , Zhao Wei , Guo Zhengang , Huang Dedong 
Published: December 2019

Abstract
A facile hydrothermal procedure was adopted to prepare TiO2 nanosheet array film on Ti foil, with NaCl as a morphology control agent. SEM, EDS, XPS and XRD showed that the TiO2 nanosheets with uniform morphology were vertically grown on the surface of Ti foil, and the nanosheets were interlaced with each other. When the hydrothermal reaction was controlled at 140 °C for 6 h, TiO2 nanosheet array film with superhydrophilicity (water contact angle of 3°) was obtained. In addition, excellent flexibility of Ti foil with TiO2 nanosheet array films could be a promising material for flexible application.
Regional imaging genetic enrichment analysis
Authors: Yao Xiaohui , Cong Shan , Yan Jingwen , Risacher Shannon L , Saykin Andrew J , Moore Jason H , Shen Li ,   UK Brain Expression Consortium,   for the Alzheimer’s Disease Neuroimaging Initiative
Published: December 2019

Abstract

Motivation
Brain imaging genetics aims to reveal genetic effects on brain phenotypes, where most studies examine phenotypes defined on anatomical or functional regions of interest (ROIs) given their biologically meaningful interpretation and modest dimensionality compared with voxelwise approaches. Typical ROI-level measures used in these studies are summary statistics from voxelwise measures in the region, without making full use of individual voxel signals.

Results
In this article, we propose a flexible and powerful framework for mining regional imaging genetic associations via voxelwise enrichment analysis, which embraces the collective effect of weak voxel-level signals and integrates brain anatomical annotation information. Our proposed method achieves three goals at the same time: (i) increase the statistical power by substantially reducing the burden of multiple comparison correction; (ii) employ brain annotation information to enable biologically meaningful interpretation and (iii) make full use of fine-grained voxelwise signals. We demonstrate our method on an imaging genetic analysis using data from the Alzheimer’s Disease Neuroimaging Initiative, where we assess the collective regional genetic effects of voxelwise FDG-positron emission tomography measures between 116 ROIs and 565 373 single-nucleotide polymorphisms. Compared with traditional ROI-wise and voxelwise approaches, our method identified 2946 novel imaging genetic associations in addition to 33 ones overlapping with the two benchmark methods. In particular, two newly reported variants were further supported by transcriptome evidences from region-specific expression analysis. This demonstrates the promise of the proposed method as a flexible and powerful framework for exploring imaging genetic effects on the brain.

Availability and implementation
The R code and sample data are freely available at https://github.com/lshen/RIGEA.

Supplementary information
Supplementary data are available at Bioinformatics online.
Terminating Exploration Of A Grid By An Optimal Number Of Asynchronous Oblivious Robots
Authors: Devismes Stéphane , Lamani Anissa , Petit Franck , Raymond Pascal , Tixeuil Sébastien 
Published: December 2019

Abstract
We consider swarms of asynchronous oblivious robots evolving into an anonymous grid-shaped network. In this context, we investigate optimal (w.r.t. the number of robots) deterministic solutions for the terminating exploration problem. We first show lower bounds in the semi-synchronous model. Precisely, we show that at least three robots are required to explore any grid of at least three nodes, even in the probabilistic case. Then, we show that at least four (resp. five) robots are necessary to deterministically explore a $\bf(2,2)$-Grid (resp. a $\bf(3,3)$-Grid). We then propose deterministic algorithms in the asynchronous model. This latter being strictly weakest than the semi-synchronous model, all the aforementioned bounds still hold in that context. Our algorithms actually exhibit the optimal number of robots that is necessary to explore a given grid. Overall, our results show that except in two particular cases, three robots are necessary and sufficient to deterministically explore a grid of at least three nodes and then terminate. The optimal number of robots for the two remaining cases is four for the $\bf(2,2)$-Grid and five for the $\bf(3,3)$-Grid, respectively.
Measuring health system resilience in a highly fragile nation during protracted conflict: South Sudan 2011–15
Authors: Odhiambo Jackline , Jeffery Caroline , Lako Richard , Devkota Baburam , Valadez Joseph J 
Published: December 2019

Abstract
Health systems resilience (HSR) is defined as the ability of a health system to continue providing normal services in response to a crisis, making it a critical concept for analysis of health systems in fragile and conflict-affected settings (FCAS). However, no consensus for this definition exists and even less about how to measure HSR. We examine three current HSR definitions (maintaining function, improving function and achieving health system targets) using real-time data from South Sudan to develop a data-driven understanding of resilience. We used 14 maternal, newborn and child health (MNCH) coverage indicators from household surveys in South Sudan collected at independence (2011) and following 2 years of protracted conflict (2015), to construct a resilience index (RI) for 9 of the former 10 states and nationally. We also assessed health system stress using conflict-related indicators and developed a stress index. We cross tabulated the two indices to assess the relationship of resilience and stress. For maintaining function for 80% of MNCH indicators, seven state health systems were resilient, compared with improving function for 50% of the indicators (two states were resilient). Achieving the health system national target of 50% coverage in half of the MNCH indicators displayed no resilience. MNCH coverage levels were low, with state averages ranging between 15% and 44%. Central Equatoria State displayed high resilience and high system stress. Lakes and Northern Bahr el Ghazal displayed high resilience and low stress. Jonglei and Upper Nile States had low resilience and high stress. This study is the first to investigate HSR definitions using a resilience metric and to simultaneously measure health system stress in FCAS. Improving function is the HSR definition detecting the greatest variation in the RI. HSR and health system stress are not consistently negatively associated. HSR is highly complex warranting more in-depth analyses in FCAS.
Longitudinal metabolomic analysis of plasma enables modeling disease progression in Duchenne muscular dystrophy mouse models
Authors: Tsonaka Roula , Signorelli Mirko , Sabir Ekrem , Seyer Alexandre , Hettne Kristina , Aartsma-Rus Annemieke , Spitali Pietro 
Published: December 2019

Abstract
Duchenne muscular dystrophy is a severe pediatric neuromuscular disorder caused by the lack of dystrophin. Identification of biomarkers is needed to support and accelerate drug development. Alterations of metabolites levels in muscle and plasma have been reported in pre-clinical and clinical cross-sectional comparisons. We present here a 7-month longitudinal study comparing plasma metabolomic data in wild-type and mdx mice. A mass spectrometry approach was used to study metabolites in up to five time points per mouse at 6, 12, 18, 24 and 30 weeks of age, providing an unprecedented in depth view of disease trajectories. A total of 106 metabolites were studied. We report a signature of 31 metabolites able to discriminate between healthy and disease at various stages of the disease, covering the acute phase of muscle degeneration and regeneration up to the deteriorating phase. We show how metabolites related to energy production and chachexia (e.g. glutamine) are affected in mdx mice plasma over time. We further show how the signature is connected to molecular targets of nutraceuticals and pharmaceutical compounds currently in development as well as to the nitric oxide synthase pathway (e.g. arginine and citrulline). Finally, we evaluate the signature in a second longitudinal study in three independent mouse models carrying 0, 1 or 2 functional copies of the dystrophin paralog utrophin. In conclusion, we report an in-depth metabolomic signature covering previously identified associations and new associations, which enables drug developers to peripherally assess the effect of drugs on the metabolic status of dystrophic mice.
Power calculations for cluster randomized trials (CRTs) with right-truncated Poisson-distributed outcomes: a motivating example from a malaria vector control trial
Authors: Mwandigha Lazaro M , Fraser Keith J , Racine-Poon Amy , Mouksassi Mohamad-Samer , Ghani Azra C 
Published: December 2019

Abstract

Background
Cluster randomized trials (CRTs) are increasingly used to study the efficacy of interventions targeted at the population level. Formulae exist to calculate sample sizes for CRTs, but they assume that the domain of the outcomes being considered covers the full range of values of the considered distribution. This assumption is frequently incorrect in epidemiological trials in which counts of infection episodes are right-truncated due to practical constraints on the number of times a person can be tested.

Methods
Motivated by a malaria vector control trial with right-truncated Poisson-distributed outcomes, we investigated the effect of right-truncation on power using Monte Carlo simulations.

Results
The results demonstrate that the adverse impact of right-truncation is directly proportional to the magnitude of the event rate, λ, with calculations of power being overestimated in instances where right-truncation was not accounted for. The severity of the adverse impact of right-truncation on power was more pronounced when the number of clusters was ≤30 but decreased the further the right-truncation point was from zero.

Conclusions
Potential right-truncation should always be accounted for in the calculation of sample size requirements at the study design stage.
Fast–slow vector fields of reaction–diffusion systems
Authors: Bykov V , Cherkinsky Y , Gol’dshtein V , Krapivnik N , Maas U 
Published: December 2019

AbstractA geometrically invariant concept of fast–slow vector fields perturbed by transport terms describing molecular diffusion is proposed in this paper. It is an extension of our concept of singularly perturbed vector fields for ODEs to reaction–diffusion systems with chemical reactions having wide range of characteristic time scales, while transport processes remain comparatively slow. Under this assumption we developed a decomposition into a fast and slow subsystems. It is assumed that the transport terms for the fast subsystem can be neglected to the leading order. For the slow subsystem we modify a concept of singularly perturbed profiles proposed in our previous works. The results are used to justify and to modify an algorithm of reaction–diffusion manifolds (REDIMs). The modified REDIM method is applied to the Michaelis–Menten model to illustrate the suggested approach.
Human gain-of-function STAT1 mutation disturbs IL-17 immunity in mice
Authors: Tamaura Moe , Satoh-Takayama Naoko , Tsumura Miyuki , Sasaki Takaharu , Goda Satoshi , Kageyama Tomoko , Hayakawa Seiichi , Kimura Shunsuke , Asano Takaki , Nakayama Manabu , Koseki Haruhiko , Ohara Osamu , Okada Satoshi , Ohno Hiroshi , Kobayashi Masao 
Published: December 2019

Abstract
Gain-of-function (GOF) mutations in the gene for signal transducer and activator of transcription 1 (STAT1) account for approximately one-half of patients with chronic mucocutaneous candidiasis (CMC) disease. Patients with GOF-STAT1 mutations display a broad variety of infectious and autoimmune manifestations in addition to CMC, and those with severe infections and/or autoimmunity have a poor prognosis. The establishment of safe and effective treatments based on a precise understanding of the molecular mechanisms of this disorder is required to improve patient care. To tackle this problem, we introduced the human R274Q GOF mutation into mice [GOF-Stat1 knock-in (GOF-Stat1R274Q)]. To investigate the immune responses, we focused on the small intestine (SI), which contains abundant Th17 cells. Stat1R274Q/R274Q mice showed excess phosphorylation of STAT1 in CD4+ T cells upon IFN-γ stimulation, consistent with the human phenotype in patients with the R274Q mutation. We identified two subpopulations of CD4+ T cells, those with ‘normal’ or ‘high’ level of basal STAT1 protein in Stat1R274Q/R274Q mice. Upon IFN-γ stimulation, the ‘normal’ level CD4+ T cells were more efficiently phosphorylated than those from WT mice, whereas the ‘high’ level CD4+ T cells were not, suggesting that the level of STAT1 protein does not directly correlate with the level of pSTAT1 in the SI. Inoculation of Stat1R274Q/R274Q mice with Candida albicans elicited decreased IL-17-producing CD4+RORγt+ cells. Stat1R274Q/R274Q mice also excreted larger amounts of C. albicans DNA in their feces than control mice. Under these conditions, there was up-regulation of T-bet in CD4+ T cells. GOF-Stat1R274Q mice thus should be a valuable model for functional analysis of this disorder.
Effects of Abdominal Rotation on Jump Performance in the AntGigantiops destructor(Hymenoptera, Formicidae)
Authors: Ye Dajia , Gibson Joshua C , Suarez Andrew V 
Published: December 2019

SynopsisJumping is an important form of locomotion, and animals employ a variety of mechanisms to increase jump performance. While jumping is common in insects generally, the ability to jump is rare among ants. An exception is the Neotropical ant Gigantiops destructor (Fabricius 1804) which is well known for jumping to capture prey or escape threats. Notably, this ant begins a jump by rotating its abdomen forward as it takes off from the ground. We tested the hypotheses that abdominal rotation is used to either provide thrust during takeoff or to stabilize rotational momentum during the initial airborne phase of the jump. We used high speed videography to characterize jumping performance of G. destructor workers jumping between two platforms. We then anesthetized the ants and used glue to prevent their abdomens from rotating during subsequent jumps, again characterizing jump performance after restraining the abdomen in this manner. Our results support the hypothesis that abdominal rotation provides additional thrust as the maximum distance, maximum height, and takeoff velocity of jumps were reduced by restricting the movement of the abdomen compared with the jumps of unmanipulated and control treatment ants. In contrast, the rotational stability of the ants while airborne did not appear to be affected. Changes in leg movements of restrained ants while airborne suggest that stability may be retained by using the legs to compensate for changes in the distribution of mass during jumps. This hypothesis warrants investigation in future studies on the jump kinematics of ants or other insects.