bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wetland methane emissions dominated by plant‐mediated fluxes: Contrasting emissions pathways and seasons within a shallow freshwater subtropical wetland
Authors: Jeffrey Luke C. , Maher Damien T. , Johnston Scott G. , Kelaher Brendan P. , Steven Andy , Tait Douglas R. 
Published: March 2019

AbstractWetlands represent the largest natural source of methane; however, very few studies have simultaneously quantified the three main atmospheric flux pathways (i.e., diffusive, ebullition, and plant‐mediated). Unlike better‐studied northern hemisphere systems, many Australian subtropical wetlands undergo extreme wet/dry oscillations, which may strongly impact methane dynamics. We assessed diurnal methane emissions of multiple pathways during three distinct seasonal events within an Australian freshwater wetland. Six‐fold higher methane emissions occurred during summer compared to autumn floods (which followed an extensive dry‐period) and winter/cool conditions. Over three seasons, diffusion represented the highest average areal fluxes (25.9 ± 73.2 mmol m−2 d−1) but were within range of fluxes through water lily aerenchyma (20.8 ± 41.5 mmol m−2 d−1). Average ebullition rates were 5.5 ± 9.7 mmol m−2 d−1. Water column CH4 displayed high spatiotemporal variability, ranging from 55.0 to 253.5 μmol L−1. Time series δ13C–CH4 isotope measurements revealed an oxidation fraction of ~ 15% at night‐time and ~ 36% during day‐time, and night‐time diffusive fluxes were consistently ~ three‐fold higher than day‐time fluxes. By aggregating seasons and weighting for changes in lily coverage, plant‐mediated fluxes accounted for ~ 59% of the annual methane emissions, whereas ebullition and diffusion each accounted for ~ 20%. The up‐scaled annual area‐weighted wetland methane flux (combined pathways) was 27.3 ± 36.7 mmol m−2 d−1. We contend that water lilies (Nymphaea sp.) are the significant carbon source, mediator, and conduit for methane fluxes in this system, and the extremely large seasonal variability of methane emissions reflect dynamic redox oscillations driven by oscillating wet and dry conditions.
Low rates of dinitrogen fixation in the eastern tropical South Pacific
Authors: Chang Bonnie X. , Jayakumar Amal , Widner Brittany , Bernhardt Peter , Mordy Calvin W. , Mulholland Margaret R. , Ward Bess B. 
Published: March 2019

AbstractRecent work has suggested that the oxygen deficient zone (ODZ) and overlying surface waters of the eastern tropical South Pacific (ETSP) is a potential niche for dinitrogen (N2) fixation. Rates of dinitrogen fixation were measured in the ETSP above and within the ODZ in July 2013 using a modified 15N2 bubble addition method, wherein a bubble was added, mixed, and then removed, and the isotopic enrichment of the dissolved N2 was measured directly for each incubation. N2 fixation rates in the euphotic zone ranged from below detection to 3.9 nmol L−1 d−1 and were below detection at all depths surveyed within the ODZ. Depth‐integrated rates ranged from below detection to 289.7 μmol m−2 d−1. DNA and RNA of diverse nifH genes were detected at both surface waters and in the ODZ. However, the results of this study suggest that N2 fixation rates were low and contribute little to N cycling in the ETSP.
The Causes and Outcomes of Early Relaparotomy Following Pediatric Living Donor Liver Transplantation
Authors: Okada Noriki , Sanada Yukihiro , Onishi Yasuharu , Urahashi Taizen , Ihara Yoshiyuki , Yamada Naoya , Hirata Yuta , Katano Takumi , Imai Toshimi , Ushijima Kentaro , Ogaki Keiko , Otomo Shinya , Mizuta Koichi 
Published: March 2019

Early relaparotomy of adult recipients after living donor liver transplantation (LDLT) is significantly associated with poor prognosis. However, there are few reports focusing on pediatric recipients after LDLT. The aim of this study is to clarify the causes and outcomes of early relaparotomy after pediatric LDLT. A total of 265 pediatric recipients (272 LDLTs) transplanted from May 2001 to October 2015 were retrospectively analyzed. Early relaparotomy was defined as surgical intervention performed within 3 months after LDLT. Early relaparotomy was performed 49 times for 33 recipients (12.5%). The recipient and graft survival rates in the early relaparotomy group were significantly lower than those in the nonearly relaparotomy group, respectively (75.0% and 63.6% versus 96.6% and 95.8%; both P < 0.001). Left lateral segment grafts were used significantly more frequently in the nonrelaparotomy group (P = 0.01). According to the multivariate analysis, the preoperative Pediatric End‐Stage Liver Disease (PELD)/Model for End‐Stage Liver Disease (MELD) score of the early relaparotomy group was significantly higher than that of the nonearly relaparotomy group (13.7 versus 6.3; P = 0.04). According to the receiver operating characteristic curve, the preoperative PELD/MELD score cutoff point was 17.2. Early relaparotomy due to infectious causes led to significantly poorer graft survival than that due to noninfectious causes (P = 0.04). In conclusion, the recipient and graft survival rates of the early relaparotomy group were significantly lower than those of the nonearly relaparotomy group. A high preoperative PELD/MELD score was a risk factor for early relaparotomy. In particular, early relaparotomy due to infection showed a poor prognosis.
Measurement of surface conductivity of graphene at W‐band
Authors: Majeed Farhat , Fickenscher Thomas , Shahpari Morteza , Thiel David V. 
Published: March 2019

AbstractGraphene has excellent mechanical and conducting properties. Scattering parameter measurements were made in W‐band (75‐110 GHz) on 25 mm × 25 mm monolayer graphene film printed on polyethylene terephthalate (PET) substrate. From near field measurements using WR10 horn antennas the surface conductivity was de‐embedded after calibrating the s11 data against the reflection of a copper plate of same cross‐sectional dimensions as the DUT and calibrating the s21 data against horn‐to‐horn measurements. A monolayer graphene strip (20 mm × 2 mm) printed on PET substrate (25 mm × 25 mm) showed higher reflection when it was aligned with the E field of the incident radiation (as compared to H field alignment). The surface conductivity of graphene was de‐embedded from s11 measurements using standard transmission line theory and from s21 measurements using cascade matrix theory. The measured real part of the surface conductivity of graphene ranges between 0.7 and 1.8 mS/sq.
Aberrant methylation of the IL‐12B promotor region contributes to the risk of developing ovarian endometriosis
Authors: Zhao Wei , Kang Shan , Zhao Jian , Wang Lixian , Cao Shiru , Li Yan 
Published: March 2019

AbstractStudies have shown that aberrant expression of IL‐12p40, which is encoded by the interleukin‐12B (IL‐12B) gene, may be involved in the development of endometriosis. In this study, we investigated the role of aberrant methylation of the
IL‐12B promoter region and its associated expression in the development of ovarian endometriosis. By using pyrosequencing, we analyzed the methylation level of the
IL‐12B promoter region in eutopic and ectopic endometrium of patients with ovarian endometriosis and normal endometrium of control women. The expression of
IL‐12B mRNA was detected by quantitative real‐time PCR. The results showed that the methylation level of the
IL‐12B promoter region in ectopic and eutopic endometrium of patients with ovarian endometriosis was significantly lower than that in endometrium of women without endometriosis (
p < 0.001 and
p = 0.041, respectively). In contrast, mRNA levels were significantly increased in ectopic and eutopic endometrium of patients with ovarian endometriosis compared to those in endometrium of women without endometriosis (
p < 0.001 and
p = 0.042, respectively). Correlation analysis showed that the methylation level of the
IL‐12B promoter region was negatively correlated with mRNA levels of
IL‐12B (
p < 0.001). Our data suggested that aberrant methylation of the
IL‐12B promoter region may be responsible for aberrant
IL‐12B mRNA expression in endometrium tissue of women, which may be associated with the development of ovarian endometriosis in northern Chinese women.
A generic approach to modelling flexible confined boundary conditions in SPH and its application
Authors: Zhao Shaohan , Bui Ha H. , Lemiale Vincent , Nguyen Giang D. , Darve Felix 
Published: March 2019

SummaryIn this paper, a new approach to applying confining stress to flexible boundaries in the smoothed particle hydrodynamics (SPH) method is developed to facilitate its applications in geomechanics. Unlike the conventional SPH methods that impose confining boundary conditions by creating extra boundary particles, the proposed approach makes use of kernel truncation properties of SPH approximations that occur naturally at free‐surface boundaries. Therefore, it does not require extra boundary particles and, as a consequence, can be utilised to apply confining stresses onto any boundary with arbitrary geometry without the need for tracking the curvature change during the computation. This enables more complicated problems that involve moving confining boundaries, such as confining triaxial tests, to be simulated in SPH without difficulties. To further enhance SPH applications in elasto‐plastic computations of geomaterials, a robust numerical procedure to implement Mohr‐Coulomb plasticity model in SPH is presented for the first time to avoid difficulties associated with corner singularities in Mohr‐Coulomb model. The proposed approach was first validated against two‐dimensional finite element (FE) solutions for confining biaxial compression tests to demonstrate its predictive capability at small deformation range when FE solutions are still valid. It is then further extended to three‐dimensional conditions and utilised to simulate triaxial compression experiments. Simulation results predicted by SPH show good agreement with experiments, FE solutions, and other numerical results available in the literature. This suggests that the proposed approach of imposing confining stress boundaries is promising and can handle complex problems that involve moving confining boundary conditions.
Handgrip Strength in Preoperative Elective Cardiac Surgery Patients and Association With Body Composition and Surgical Risk
Authors: Perry Ingrid Schweigert , Pinto Lourena C. , da Silva Taís Kereski , Vieira Sílvia R. R. , Souza Gabriela Corrêa 
Published: March 2019

AbstractBackgroundHandgrip strength (HGS) is a potential method to approximate perioperative risk in cardiothoracic surgery patients and correlates well with European System for Cardiac Operative Risk Evaluation (EuroSCORE) values. This study aimed to characterize the functional capacity in preoperative cardiac surgery patients through HGS.MethodsThis cross‐sectional study investigated patients aged 18 years or older. The collected data included surgical risk (EuroSCORE), body mass index (BMI), body composition (electrical bioimpedance), and HGS.ResultsThe mean age of the 278 participants was 62.1 ± 11.2 years, of whom 61.5% were male, 43.2% were overweight, and 26.3% were obese. The main types of surgery were myocardial revascularization (50%) and valve replacement (40.6%). HGS values differed between genders in all age groups (P < 0.05) and were approximately 40% lower than reference values for healthy individuals. The values differed with respect to operative risk (P = 0.003) and had a moderate positive correlation with fat‐free mass (rs = 0.435, P < 0.001), a moderate negative correlation with fat mass (rs = −0.447, P < 0.001), and weak negative correlations with age (rs = −0.270, P < 0.01) and EuroSCORE (rs = −0.316, P < 0.01).ConclusionsThe HGS values of preoperative elective cardiac surgery patients were below reference values for healthy individuals, were lower in male patients, were positively correlated with fat‐free mass, and were negatively correlated with fat mass, age, and operative risk. Its preoperative use in these patients is an attractive complementary method of risk assessment in clinical practice.
The value of high‐dose radiotherapy in intracranial ependymoma
Authors: Ager Bryan J. , Christensen Michael T. , Burt Lindsay M. , Poppe Matthew M. 
Published: March 2019

AbstractBackgroundWe sought to evaluate the impact of adjuvant radiotherapy dose on overall survival (OS) after surgical resection for localized intracranial ependymoma.ProcedureThe National Cancer Database (NCDB) was queried from 2004 to 2015 for patients of all ages with intracranial WHO grade II to III ependymoma treated with surgery and 4500 to 7000 cGy of adjuvant radiotherapy. Pearson χ2 test and multivariate logistic regression analyses were used to assess clinicodemographic factors and patterns of care. After propensity‐score matching, OS was assessed with Kaplan–Meier analyses and doubly robust estimation with multivariate Cox proportional hazards modeling.ResultsOf the 1153 patients meeting criteria, 529 (46%) received ≤ 5400 cGy and 624 (54%) received > 5400 cGy. At a median follow‐up of 54.5 months, an OS benefit was observed for > 5400 cGy in pediatric patients aged 2–18 years (hazard ratio [HR] 0.53; 95% confidence interval [CI] 0.28–0.99, P = 0.047). No OS difference was found between ≤ 5400 cGy and > 5400 cGy in pediatric patients aged < 2 years (P = 0.819) or in adults (P = 0.180). Increasing age, WHO grade III, subtotal resection, and receipt of chemotherapy portended worse OS. Age 2 to 18 years, WHO III grade, supratentorial location, and receipt of chemotherapy were associated with receiving > 5400 cGy.ConclusionAdjuvant radiotherapy dose > 5400 cGy was associated with improved OS for children aged 2–18 years with WHO grade II‐III intracranial ependymoma. No OS benefit was found with > 5400 cGy in adults or children less than two years of age.
Zika virus during pregnancy: From maternal exposure to congenital Zika virus syndrome
Authors: Pomar Léo , Musso Didier , Malinger Gustavo , Vouga Manon , Panchaud Alice , Baud David 
Published: March 2019

What is already known about the topic?The Zika virus (ZIKV) emergence and its consequences during pregnancy led to an increasing number of data about the maternal and fetal consequences of ZIKV infections.What does this study add?This review evaluates risks of maternal ZIKV infection, maternal‐fetal transmission, congenital Zika syndrome (CZS), other adverse perinatal outcomes, and long‐term sequelae among pregnancies exposed to ZIKV. This review also provides contemporary criteria and guidelines for the follow‐up of exposed fetuses, based on prenatal and postnatal features of CZS.
The Nucleotide‐Dependent Interactome of Rice Heterotrimeric G‐Protein α ‐Subunit
Authors: Biswal Akshaya Kumar , McConnell Evan Wesley , Werth Emily Grace , Lo Shuen‐Fang , Yu Su‐May , Hicks Leslie M. , Jones Alan M. 
Published: March 2019

AbstractThe rice heterotrimeric G‐protein complex, a guanine‐nucleotide‐dependent on‐off switch, mediates vital cellular processes and responses to biotic and abiotic stress. Exchange of bound GDP (resting state) for GTP (active state) is spontaneous in plants including rice and thus there is no need for promoting guanine nucleotide exchange in vivo as a mechanism for regulating the active state of signaling as it is well known for animal G signaling. As such, a master regulator controlling the G‐protein activation state is unknown in plants. Therefore, an ab initio approach is taken to discover candidate regulators. The rice Gα subunit (RGA1) is used as bait to screen for nucleotide‐dependent protein partners. A total of 264 proteins are identified by tandem mass spectrometry of which 32 were specific to the GDP‐bound inactive state and 22 specific to the transition state. Approximately, 10% are validated as previously identified G‐protein interactors.
DFT studies on new family of high‐energy density energetic bis(trinitromethyl) azo tetrazoles and triazoles
Authors: He Piao , Zhang Jianguo , Wu Jinting 
Published: March 2019

AbstractDensity functional theory (DFT) methods were employed to design a new family of high‐energy density energetic bis(trinitromethyl) azo tetrazoles and triazoles. The optimized geometry, electronic properties, IR spectrum, and thermodynamics were calculated for inspecting the molecular stability and chemical reactivity. Their energetic parameters, including density, heats of formation, detonation properties, and impact sensitivity, were extensively evaluated as well. These newly designed bis(trinitromethyl)‐azo‐azoles exhibit moderate impact sensitivities, high density (above 1.9 g cm−3), excellent heats of formation (up to 1076.08 kJ mol−1), and good detonation performance, which in some cases (D = 9.53 km s−1, P = 41.37 GPa) overmatches the high‐energy explosive HMX, making them promising candidates of new environmentally friendly high‐energy‐density compounds (HEDCs).
Theoretical investigation about the excited‐state proton transfer mechanism for a novel dihydorgen bond system
Authors: Wang Lifei , Wang Yan , Zhao Juan , Zhao Jinfeng 
Published: March 2019

AbstractIt is well known that excited‐state dynamical behavior is of paramount importance in photochemical processes. In this present work, we theoretically explore a novel dihydrogen bond system (3‐enol) based on density functional theory (DFT) and time‐dependent density functional theory (TDDFT) methods. Firstly, we calculate the electrostatic potential surface (EPS) for 3‐enol in the S0 state, which reveals the formation of dual intramolecular hydrogen bonds in 3‐enol form. Furthermore, comparing the hydrogen bonding bond lengths and bong angles, we verify that dual intramolecular hydrogen bonds should be strengthened in the S1 state. And the infrared (IR) stretching vibrational spectra involved in hydrogen bonding hydroxyl moieties further reveal the enhanced dual hydrogen bonds in the S1 state. In view of photo‐induced behavior, based on frontier molecular orbitals (MOs) analyses, we find that the charge redistribution around hydrogen bonding moieties could facilitate the excited‐state intramolecular proton transfer (ESIPT) reaction for 3‐enol system. In the end, we construct the potential energy surfaces along with dual hydrogen bonding wires in both S0 and S1 states, which clarifies that only the single proton transfer happens in the S1 state even though 3‐enol owns dual intramolecular hydrogen bonds.
Thieno[3,2‐b]Thiophene End‐Capped all‐Sulfur Analog of 3,4‐Ethylenedioxythiophene and its Eletrosynthesized Polymer: Is Distorted Conformation Not Suitable for Electrochromism?
Authors: Xue Yu , Xue Zexu , Zhang Wenwen , Zhang Wenna , Chen Shuai , Lin Kaiwen , Xu Jingkun 
Published: March 2019

ABSTRACTBy employing planar thieno[3,2‐b]thiophene (TT) as end‐capped units and famous 3,4‐ethylenedioxythiophene (EDOT) or its all‐sulfur analog 3,4‐ethylenedithiathiophene (EDTT) as cores, two conjugated oligomer, TT‐EDOT‐TT and TT‐EDTT‐TT, have been synthesized and electropolymerized into electrochromic polymer films, P(TT‐EDOT‐TT) and P(TT‐EDTT‐TT), respectively. Due to strongly noncovalent inter/intramolecular interactions from SS attraction of TT‐EDTT‐TT, it has twisted molecular configuration in contrast to planar TT‐EDOT‐TT. Spectroscopic, electrochemical, morphological as well as theoretical calculation studies of these oligomers or polymers were carried out to reveal the significant influence of such molecular geometry on their physicochemical and optoelectronic properties. According to electrochromic kinetics, P(TT‐EDTT‐TT) presented preferable electrochromic behavior such as the higher optical contrast (70.8%), favorable coloration efficiency (331.3 cm2 C−1) and fast response time (0.72 s). This research will help us deeply understand the effect of spatial organization of precursor molecules on the properties of electrochromic polymers and provides a promising strategy to develop high‐performance electrochromic materials. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1041–1048
Effect of a post‐annealing process on microstructure and mechanical properties of high‐density polyethylene/silica nanocomposites
Authors: Guichard Bryan , Cassagnau Philippe , Sudre Guillaume , Fulchiron René , Ledieu Bastien , Espuche Eliane 
Published: March 2019

ABSTRACTHigh‐density polyethylene (HDPE) and nanosilica nanocomposites were prepared for SiO2 content up to 15 wt%. Microstructural characterization evidenced a homogenous distribution of silica aggregates with a mean size increasing with the filler content finally resulting in a rheological percolation between 7.5 and 10 wt%. Nanoparticles did not induce any significant impact on the matrix crystallinity but led to a real improvement on elastic properties accompanied with a large embrittlement above the percolation threshold. The effect of annealing near HDPE melting temperature was studied. Differential scanning calorimetry, X‐ray diffraction, and small‐angle X‐ray scattering analyses showed a significant change in the HDPE microstructure after annealing at 125°C. A large increase in the crystallinity (from 68 to 76%) and a clear improvement of Young's modulus (by 55%) were observed prior to polymer degradation. A valuable impact of silica particles on thermal stability was also obvious regarding the evolution of elastic properties for extended exposure times (850–1,200 h). © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2019, 57, 535–546
US pediatric pulmonology workforce
Authors: Harris Christopher , Katkin Julie , Cataletto Mary , Dorkin Henry , Laskosz Laura , Ruch‐Ross Holly 
Published: March 2019

AbstractAimChildren with respiratory conditions benefit from care provided by pediatric pulmonologists. As these physicians are a small portion of the overall pediatric workforce, it is necessary to understand the practices and career plans of these specialists.MethodsAn internet survey was developed by the American Academy of Pediatrics Division of Workforce and Medical Education Policy and sent to members of the American Academy of Pediatrics and American College of Chest Physicians who identified as pediatric pulmonary physicians.ResultsResponses were received from 485 physicians and were compared to the results of a similar survey done in 1997. Of those completing the survey, 63% were male and 37% female, with increased number of females since the earlier poll. The average calculated age was 56 years. They worked 54 h per week, down from 59 h in the prior survey. Pediatric pulmonologists are overwhelmingly clinicians (92%) with major responsibilities for administration (79%), teaching (78%), and research. Basic science research was rarely reported (7%). Pediatric pulmonologists felt that referrals had become more complicated in the recent past. Nearly all planned to maintain Pediatric Pulmonology Sub‐board certification, though one third planned to cut back on clinical workload in the next decade. Many were concerned that the number needed in the profession in a decade would be inadequate with significant concerns about funding for those positions.ConclusionOverall, these results reflect the current state of the workforce and the need to monitor the supply of practitioners in the future.