bluuebunny/crossref_metadata_2025_split huggingface dataset:
Epitaxial Growth of Urchin‐Like CoSe2 Nanorods from Electrospun Co‐Embedded Porous Carbon Nanofibers and Their Superior Lithium Storage Properties
Authors: Wang Jinkai , Wang Hongkang , Cao Daxian , Lu Xuan , Han Xiaogang , Niu Chunming 
Published: September 2017

AbstractA facile synthesis of porous graphitic carbon nanofibers (CNFs) with encapsulated Co nanoparticles (denote as Co@CNFs) via electrospinning and subsequent annealing is reported. The in situ generated Co nanoparticles (NPs) promote the CNF graphitization under a low temperature of 700 °C, which simultaneously results in the porous structure of the Co@CNFs with a large surface area (416 m2 g−1). Furthermore, urchin‐like CoSe2 nanorods are epitaxially grown from the Co@CNFs via a facile hydrothermal selenation, in which the embedded Co NPs serve as directing seeds and sacrificial Co‐source, and CoSe2 nanorods are rooted into the CNFs (denote as CoSe2@CNFs). When used as anode materials for lithium ion batteries, the CoSe2@CNFs demonstrate superior lithium storage properties, delivering a high reversible capacity of 1405 mA h g−1 after 300 cycles at a current density of 200 mA g−1. The enhanced lithium storage performance can be attributed to the novel hybrid structure, namely, the porous and graphitic CNFs can not only facilitate the charge/ion transfer but also buffer the volume changes of the electrode during lithiation/delithiation processes. More importantly, a general strategy is provided to graphitize amorphous carbon materials via the use of in situ generated transition metal nanoparticles as catalyst.
The inherent matrix properties of lichen metabolites in matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry
Authors: Le Pogam Pierre , Boustie Joël , Richomme Pascal , Denis Antoine , Schinkovitz Andreas 
Published: September 2017

RationaleLight‐absorbing secondary metabolites from lichens were recently reported to exhibit promising Laser Desorption Ionization (LDI) properties, enabling their direct detection from crude lichen extracts. In addition, many of them display close structural homologies to commercial Matrix‐Assisted Laser Desorption Ionization (MALDI) matrices, which is incentive for the evaluation of their matrical properties. The current study systematically evaluated the matrix effects of several structural classes of lichen metabolites: monoaromatic compounds, quinone derivatives, dibenzofuran‐related molecules and the shikimate‐derived vulpinic acid. Their matrical properties were tested against a wide range of structurally diverse analytes including alkaloids, coumarins, flavonoids and peptides.MethodsTriplicate automatic positive‐ion mode MALDI analyses were carried out and ionization efficiencies were compared with those of structurally related reference matrices (i.e. DHB, HCCA, dithranol and usnic acid) in terms of (i) analyte absolute intensities and (ii) Matrix Suppressing Effect (MSE) scores.ResultsMonoaromatic lichen metabolites revealed matrical properties similar to those of DHB when obtained under comparable experimental conditions. Likewise, anthraquinone metabolites triggered ionization of tested analytes in a similar way to the structurally related dithranol. Finally, dibenzofuran derivatives displayed a broad ionization profile, reminiscent of that of (+)‐usnic acid.ConclusionsLichen metabolites exhibit interesting MALDI matrix properties, especially for medium and low molecular weight analytes. For many of the tested molecules, matrix ion formation was very limited. This proof‐of‐concept study paves the way for follow‐up investigations to assess the matrix properties of lichen metabolites against a wider array of analytes as well as adapting experimental settings to individually optimize the performance of successfully tested candidates.
Analysis of ToF‐SIMS spectra of poly(2‐vinylpyridine) and poly(4‐vinylpyridine) with density functional theory calculations
Authors: Wong Chi Pui Jeremy , Ng Kai‐Mo , Weng Lu‐Tao , Lun Yeung King , Chan Chi Ming 
Published: September 2017

The time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) positive and negative ion spectra of poly(2‐vinylpyridine) (P2VP) and poly(4‐vinylpyridine) (P4VP) were analyzed using density functional theory calculations. Most of the ions from these structural isomers shared the same accurate mass, but had different relative abundance. This could be attributed to the fact that from a thermodynamics perspective, the disparity in the molecular structures can affect the ion stability if we assume that they shared the same mechanistic pathway of formation with similar reaction kinetics. The molecular structures of these ions were assigned, and their stability was evaluated based on calculations using the Kohn‐Sham density functional theory with Becke's 3‐parameter Lee‐Yang‐Parr exchange‐correlation functional and a correlation‐consistent, polarized, valence, double‐zeta basis set for cations and the same basis set with a triple‐zeta for anions. The computational results agreed with the experimental observations that the nitrogen‐containing cations such as C5H4N+ (m/z = 78), C8H7N+· (m/z = 117), C8H8N+ (m/z = 118), C9H8N+ (m/z = 130), C13H11N2+ (m/z = 195), C14H13N2+ (m/z = 209), C15H15N2+ (m/z = 223), and C21H22N3+ (m/z = 316) ions were more favorably formed in P2VP than in P4VP due to higher ion stability because the calculated total energies of these cations were more negative when the nitrogen was situated at the ortho position. Nevertheless, our assumption was invalid in the formation of positive ions such as C6H7N+˙ (m/z = 93) and C8H10N+ (m/z = 120). Their formation did not necessarily depend on the ion stability. Instead, the transition state chemistry and the matrix effect both played a role. In the negative ion spectra, we found that nitrogen‐containing anions such as C5H4N− (m/z = 78), C6H6N− (m/z = 92), C7H6N− (m/z = 104), C8H6N− (m/z = 116), C9H10N− (m/z = 132), C13H11N2− (m/z = 195), and C14H13N2− (m/z = 209) ions were more favorably formed in P4VP, which is in line with our computational results without exception. We speculate that whether anions would form from P2VP and P4VP is more dependent on the stability of the ions.
Hydrogen‐rich superconductors at high pressures
Authors: Wang Hui , Li Xue , Gao Guoying , Li Yinwei , Ma Yanming 
Published: September 2017

The hydrogen‐rich superconductors stabilized at high‐pressure conditions have been the subject of topic interests. There is an essential hope that hydrogen‐rich superconductors are promising candidates of room‐temperature superconductors. Recent advances in first‐principles crystal structure prediction techniques have opened up the possibility of reliable prediction of superconductive structures, and subsequent superconductivity calculations based on phonon‐mediated superconducting mechanism revealed a general appearance of high temperature superconductivity in pressurized hydrides. Theory‐orientated experiments at high pressure discovered a number of hydrogen‐rich superconductors, among which sulfur hydrides exhibit a remarkably high superconducting critical temperature reaching 203 K. In this review, we discuss the emerging research activities towards hydrogen‐rich superconductors at high pressures and outlook the future direction in the field. WIREs Comput Mol Sci 2018, 8:e1330. doi: 10.1002/wcms.1330This article is categorized under:

Structure and Mechanism > Computational Materials Science
An alternative minimally invasive technique for genetic sampling of bats: Wing swabs yield species identification
Authors: Player Delanie , Lausen Cori , Zaitlin Beryl , Harrison Jori , Paetkau David , Harmston Erin 
Published: September 2017

ABSTRACTBat species are traditionally identified morphologically, but in some cases, species can be difficult to differentiate. Wing punches (biopsies) of wing or tail membranes are commonly used to collect tissue for DNA analysis, but less invasive techniques are preferable. As such, DNA acquired using buccal and wing swabs or from fecal pellets are increasingly being employed. We compared a dry swabbing technique with the wing biopsy technique for DNA collection. We compared species identification between tissue biopsies and wing swabs collected from bats in Alberta and British Columbia, Canada, between April and November, 2014, and September and October 2015. Species identification was achieved with varying methods of field collection and lab processing. DNA was extracted, sequenced, and compared with reference sequences and field identifications. We concluded that wing swabs are an effective way to identify bat species genetically and far less invasive than biopsy techniques. These methods should be considered for genetically sampling bats, especially during seasons when wounds from biopsy are slow to heal. © 2017 The Wildlife Society.
Macroscopic damage laws based on analysis of microscopic unit cells
Authors: Brünig Michael , Hagenbrock Vanessa , Gerke Steffen 
Published: September 2017

AbstractThe paper deals with the influence of the stress state on the damage and fracture behavior of ductile metals. A continuum damage model is discussed taking into account the effect of the stress triaxiality and the Lode parameter on damage criteria and on evolution equations of damage strains. To get insight in the complex damage and failure mechanisms on the micro‐level and their effect on the macroscopic behavior of material samples series of three‐dimensional micro‐mechanical numerical analyses of void containing unit cells have been performed with special focus on shear dominated loading cases. In the present analysis periodic boundary conditions have been used to model the deformation behavior of the unit cells. Numerical results are compared with those based on symmetry boundary conditions. The results are also used to develop equations for stress‐state‐dependent damage criteria and to propose evolution equations of damage strains also depending on the current stress state. The effect of the respective boundary conditions on damage equations on the macro‐scale is critically discussed.
Morphine exposure and maternal deprivation during the early postnatal period alter neuromotor development and nerve growth factor levels
Authors: de Oliveira Carla , Scarabelot Vanessa L. , Vercelino Rafael , Silveira Natalia P. , Adachi Lauren N.S. , Regner Gabriela G. , Silva Lisiane S. , de Macedo Isabel Cristina , de Souza Andressa , Caumo Wolnei , Torres Iraci L.S. 
Published: September 2017

AbstractThe objective of this study was to verify whether repeated morphine administration and maternal deprivation in early life alter neurobehavioral development and central nerve growth factor (NGF) levels. A total of 58 male Wistar rat pups were used in our study. From postnatal day 1 (P1), litters were daily deprived of their mother for 3 h; this was continued for the first 10 days of life. Animals were divided into 5 groups: total control (C), did not receive any intervention; saline (S), received saline solution; morphine (M), received morphine; deprived‐saline group (DS), were subjected to maternal deprivation and received saline solution; and deprived‐morphine (DM), were subjected to maternal deprivation and received morphine. From P8, newborns received subcutaneous (s.c.) injections of morphine or saline (5 μg) once daily for 7 days. Righting reflex, negative geotaxis and gait were chosen as postural parameters to evaluate neuromotor reflexes. In the righting reflex test, a delay in the development of animals was evidenced in the M group. Performance of negative geotaxis was slower in the M and DM groups. In the gait test, all groups showed a daily improvement in performance in terms of locomotion frequency. An increased frequency of rearing was observed in the M, DS, and DM groups from P16 to P20. The DM group presented an increase in NGF levels in the brainstem. An increase in cerebral cortex NGF levels in the M, DS, and DM groups was observed as well. Our results suggest that changes in environmental conditions and the disruption of mother–infant interactions during the neonatal period can produce changes in the neurobiology, physiology, and emotional behavior of rats. This finding has important implications for the maternal‐neonate interaction needed for normal brain development in newborns.
Predicting Multidrug-Resistant Gram-Negative Bacterial Colonization and Associated Infection on Hospital Admission
Authors: Tseng Wen-Pin , Chen Yee-Chun , Yang Bey-Jing , Chen Shang-Yu , Lin Jr-Jiun , Huang Ya-Huei , Fu Chia-Ming , Chang Shan-Chwen , Chen Shey-Ying 
Published: September 2017

OBJECTIVEIsolation of multidrug-resistant gram-negative bacteria (MDR-GNB) from patients in the community has been increasingly observed. A prediction model for MDR-GNB colonization and infection risk stratification on hospital admission is needed to improve patient care.METHODSA 2-stage, prospective study was performed with 995 and 998 emergency department patients enrolled, respectively. MDR-GNB colonization was defined as isolates resistant to 3 or more classes of antibiotics, identified in either the surveillance or early (≤48 hours) clinical cultures.RESULTSA score-assigned MDR-GNB colonization prediction model was developed and validated using clinical and microbiological data from 995 patients enrolled in the first stage of the study; 122 of these patients (12.3%) were MDR-GNB colonized. We identified 5 independent predictors: age>70 years (odds ratio [OR], 1.84 [95% confidence interval (CI), 1.06–3.17]; 1 point), assigned point value in the model), residence in a long-term-care facility (OR, 3.64 [95% CI, 1.57–8.43); 3 points), history of cerebrovascular accidents (OR, 2.23 [95% CI, 1.24–4.01]; 2 points), hospitalization within 1 month (OR, 2.63 [95% CI, 1.39–4.96]; 2 points), and recent antibiotic exposure (OR, 2.18 [95% CI, 1.16–4.11]; 2 points). The model displayed good discrimination in the derivation and validation sets (area under ROC curve, 0.75 and 0.80, respectively) with the best cutoffs of<4 and ≥4 points for low- and high-risk MDR-GNB colonization, respectively. When applied to 998 patients in the second stage of the study, the model successfully stratified the risk of MDR-GNB infection during hospitalization between low- and high-risk groups (probability, 0.02 vs 0.12, respectively; log-rank test, P<.001).CONCLUSIONA model was developed to optimize both the decision to initiate antimicrobial therapy and the infection control interventions to mitigate threats from MDR-GNB.Infect Control Hosp Epidemiol 2017;38:1216–1225
Mary, a Pipeline to Aid Discovery of Optical Transients
Authors: Andreoni I. , Jacobs C. , Hegarty S. , Pritchard T. , Cooke J. , Ryder S. 
Published: September 2017

AbstractThe ability to quickly detect transient sources in optical images and trigger multi-wavelength follow up is key for the discovery of fast transients. These include events rare and difficult to detect such as kilonovae, supernova shock breakout, and ‘orphan’ Gamma-ray Burst afterglows. We present the Mary pipeline, a (mostly) automated tool to discover transients during high-cadenced observations with the Dark Energy Camera at Cerro Tololo Inter-American Observatory (CTIO). The observations are part of the ‘Deeper Wider Faster’ programme, a multi-facility, multi-wavelength programme designed to discover fast transients, including counterparts to Fast Radio Bursts and gravitational waves. Our tests of the Mary pipeline on Dark Energy Camera images return a false positive rate of ~2.2% and a missed fraction of ~3.4% obtained in less than 2 min, which proves the pipeline to be suitable for rapid and high-quality transient searches. The pipeline can be adapted to search for transients in data obtained with imagers other than Dark Energy Camera.
Late Pleistocene to Holocene history of Lake Warner and its prehistoric occupations, Warner Valley, Oregon (USA)
Authors: Wriston Teresa , Smith Geoffrey M. 
Published: September 2017

AbstractDuring the late Pleistocene, Warner Valley (Oregon, USA) was filled by Lake Warner; however, little is known about its rise and fall and how its changing lake levels effected the distribution of the valley’s earliest occupants. The discovery of Paleoindian projectile points along ancient shorelines of the lake spurred us to examine them for geochronological controls to aid in constructing the lake’s history. We found that Lake Warner filled the valley floor between ca. 30,000 and 10,300 cal yr BP, probably reaching its maximum ca. 17,000–16,100 cal yr BP before it began to recede. People arrived with Clovis and Western Stemmed Tradition (WST) projectile points before ca. 12,800 cal yr BP, around the time the lake stalled in its retreat. When the lake continued its decline, people using WST points followed it southward into the valley floor, where dune-and-slough topography began developing ca. 10,300 cal yr BP in response to episodic wetting and drying during the early Holocene. By the time Mazama tephra fell, ca. 7600 cal yr BP, the once large lake was divided into a series of small lakes, ponds, and sloughs that attracted people to their abundant resources of endemic fish and marsh plants.
STEEL SLAG AMENDMENT INCREASES NUTRIENT AVAILABILITY AND RICE YIELD IN A SUBTROPICAL PADDY FIELD IN CHINA
Authors: WANG WEIQI , SARDANS JORDI , WANG CHUN , ZENG CONGSHENG , TONG CHUAN , BARTRONS MIREIA , PEÑUELAS JOSEP 
Published: September 2017

SUMMARYRice is the main food for most of the human population, so sustainable rice production is very important for food security. The fertility of the soil in paddy fields is the key factor controlling rice growth and production. Steel slag amendment is becoming an effective method to increase the soil fertility, stabilize rice production and reduce greenhouse-gas emissions in Asiatic paddy fields (i.e. Korea, Japan, Bangladesh and China). We studied the relationships of steel slag amendment with plant–soil nutrient allocation, stoichiometry and rice yield in a paddy field in subtropical China. Amendment was associated with higher soil N and P availability, lower available-N:available-P ratio and higher available Ca and Si concentrations. Increases in P, Ca and Mg availability were correlated with high yields. High yields under steel slag amendment were also associated with high foliar and stem N and P concentrations and lower N:P ratios and with high shoot/root N and P concentration ratios, traits that are typically associated with productive ecosystems able to support species with high growth rates. The positive correlation between steel slag application and yield was partially due to an indirect effect (35% of the total effect) of enhancement of soil Ca, Si and P availability, which were positively correlated with yield. Steel slag amendment in this paddy field increased plant growth and yield by enhancing nutrient availability, altering soil and plant stoichiometry and shifting stem:root nutrient allocation.
Multi-level obstruction in obstructive sleep apnoea: prevalence, severity and predictive factors
Authors: Phua C Q , Yeo W X , Su C , Mok P K H 
Published: September 2017

AbstractObjectives:To characterise multi-level obstruction in terms of prevalence, obstructive sleep apnoea severity and predictive factors, and to collect epidemiological data on upper airway morphology in obstructive sleep apnoea patients.Methods:Retrospective review of 250 obstructive sleep apnoea patients.Results:On clinical examination, 171 patients (68.4 per cent) had multi-level obstruction, 49 (19.6 per cent) had single-level obstruction and 30 (12 per cent) showed no obstruction. Within each category of obstructive sleep apnoea severity, multi-level obstruction was more prevalent. Multi-level obstruction was associated with severe obstructive sleep apnoea (more than 30 events per hour) (p = 0.001). Obstructive sleep apnoea severity increased with the number of obstruction sites (correlation coefficient = 0.303, p < 0.001). Multi-level obstruction was more likely in younger (p = 0.042), male (p = 0.045) patients, with high body mass index (more than 30 kg/m2) (p < 0.001). Palatal (p = 0.004), tongue (p = 0.026) and lateral pharyngeal wall obstructions (p = 0.006) were associated with severe obstructive sleep apnoea.Conclusion:Multi-level obstruction is more prevalent in obstructive sleep apnoea and is associated with increased severity. Obstruction at certain anatomical levels contributes more towards obstructive sleep apnoea severity.
Aerosols as a source of dissolved black carbon to the ocean
Authors: Bao Hongyan , Niggemann Jutta , Luo Li , Dittmar Thorsten , Kao Shuh-Ji 
Published: September 2017

AbstractDissolved black carbon (DBC) is the largest known slow-cycling organic carbon pool in the world’s oceans. Atmospheric deposition could significantly contribute to the oceanic DBC pool, but respective information is lacking. Here we estimate that, during the dust outbreak season, the atmospheric dry deposition of water-soluble black carbon (WSBC) is ~ 40% of the riverine input to the China coastal seas. The molecular composition of atmospheric WSBC determined by ultrahigh-resolution mass spectrometry, reveals similar soil-derived sources as for riverine discharge. WSBC is significantly positively correlated with water-soluble organic carbon (WSOC) in marine aerosols, and water-soluble black carbon contributes on average 2.8 ± 0.65% to the total WSOC. Based on this relationship, the global atmospheric deposition of DBC to the ocean is estimated to be 1.8 ± 0.83 Tg yr−1. Anticipated future changes in biomass burning and dust mobilization might increase these numbers, with consequences for regional ecosystems and global carbon reservoirs.
Hypoxia inducible factor HIF-1 promotes myeloid-derived suppressor cells accumulation through ENTPD2/CD39L1 in hepatocellular carcinoma
Authors: Chiu David Kung-Chun , Tse Aki Pui-Wah , Xu Iris Ming-Jing , Di Cui Jane , Lai Robin Kit-Ho , Li Lynna Lan , Koh Hui-Yu , Tsang Felice Ho-Ching , Wei Larry Lai , Wong Chun-Ming , Ng Irene Oi-Lin , Wong Carmen Chak-Lui 
Published: September 2017

AbstractMyeloid-derived suppressor cells (MDSCs) possess immunosuppressive activities, which allow cancers to escape immune surveillance and become non-responsive to immune checkpoints blockade. Here we report hypoxia as a cause of MDSC accumulation. Using hepatocellular carcinoma (HCC) as a cancer model, we show that hypoxia, through stabilization of hypoxia-inducible factor-1 (HIF-1), induces ectoenzyme, ectonucleoside triphosphate diphosphohydrolase 2 (ENTPD2/CD39L1), in cancer cells, causing its overexpression in HCC clinical specimens. Overexpression of ENTPD2 is found as a poor prognostic indicator for HCC. Mechanistically, we demonstrate that ENTPD2 converts extracellular ATP to 5′-AMP, which prevents the differentiation of MDSCs and therefore promotes the maintenance of MDSCs. We further find that ENTPD2 inhibition is able to mitigate cancer growth and enhance the efficiency and efficacy of immune checkpoint inhibitors. Our data suggest that ENTPD2 may be a good prognostic marker and therapeutic target for cancer patients, especially those receiving immune therapy.