bluuebunny/crossref_metadata_2025_split huggingface dataset:
The challenge of accurately quantifying future megadrought risk in the American Southwest
Authors: Coats Sloan , Mankin Justin S. 
Published: August 2016

AbstractAmerican Southwest (ASW) megadroughts represent decadal‐scale periods of dry conditions the near‐term risks of which arise from natural low‐frequency hydroclimate variability and anthropogenic forcing. A large single‐climate‐model ensemble indicates that anthropogenic forcing increases near‐term ASW megadrought risk by a factor of 100; however, accurate risk assessment remains a challenge. At the global‐scale we find that anthropogenic forcing may alter the variability driving megadroughts over 55% of land areas, undermining accurate assessments of their risk. For the remaining areas, current ensembles are too small to characterize megadroughts' driving variability. For example, constraining uncertainty in near‐term ASW megadrought risk to 5 percentage points with high confidence requires 287 simulations. Such ensemble sizes are beyond current computational and storage resources, and these limitations suggest that constraining errors in near‐term megadrought risk projections with high confidence—even in places where underlying variability is stationary—is not currently possible.
Nature of turbulence, dissipation, and heating in space plasmas: From Alfvén waves to kinetic Alfvén waves
Authors: Wu D. J. , Feng H. Q. , Li B. , He J. S. 
Published: August 2016

AbstractThe nature of turbulence, dissipation, and heating in plasma media has been an attractive and challenge problem in space physics as well as in basic plasma physics. A wide continuous spectrum of Alfvénic turbulence from large MHD‐scale Alfvén waves (AWs) in the inertial turbulence regime to small kinetic‐scale kinetic AWs (KAWs) in the dissipation turbulence regime is a typical paradigm of plasma turbulence. The incorporation of current remote observations of AWs in the solar atmosphere, in situ satellite measurements of Alfvénic turbulence in the solar wind, and experimental investigations of KAWs on large plasma devices in laboratory provides a chance synthetically to study the physics nature of plasma turbulence, dissipation, and heating. A session entitled “Nature of Turbulence, Dissipation, and Heating in Space Plasmas: From Alfvén Waves to Kinetic Alfvén Waves” was held as a part of the twelfth Asia Oceania Geosciences Society Annual Meeting, which took place in Singapore between 2 and 7 August 2015. This special section is organized based on the session.
Saltier sea surface water conditions recorded by multiple mid‐Holocene corals in the northern South China Sea
Authors: Guo Yangrui , Deng Wenfeng , Chen Xuefei , Wei Gangjian , Yu Kefu , Zhao Jian‐xin 
Published: August 2016

AbstractThe typical features of the mid‐Holocene can be used to better understand present‐day climate conditions and the potential trends of future climate change. The surface conditions, including sea surface temperature (SST) and sea surface salinity (SSS), of the South China Sea (SCS) are largely controlled by the East Asian monsoon system. Surface water conditions reconstructed from coral proxies can be used to study the evolution of the East Asian monsoon during the mid‐Holocene. However, there are some discrepancies among existing coral‐based studies regarding whether the mid‐Holocene sea surface water was much saltier than the present day surface waters. Based on paired Sr/Ca and δ18O of modern and three fossil corals, this paper reconstructs the patterns of seasonal variation in SSS during the mid‐Holocene in the northern SCS. The Δδ18O records (a proxy for SSS) derived from the three fossil corals were all heavier than that from the modern coral, which suggests the presence of more saline surface waters during the mid‐Holocene in the northern SCS. These results are consistent with previous studies based on records reconstructed from coral and foraminifera, as well as from numerical simulations. Reduced rainfall caused by the strengthened Asian Monsoon and/or the northward shift of the intertropical convergence zone during the mid‐Holocene would explain the increased salinity of the surface waters of the northern SCS. The findings presented here clarify the discrepancies among previous studies and confirm the existence of saltier surface waters in the northern SCS during the mid‐Holocene.
Seeking reasons for the differences in size spectra of electrified storms over land and ocean
Authors: Bang Sarah D. , Zipser Edward J. 
Published: August 2016

AbstractThis study expands upon the results of Bang and Zipser (2015), which demonstrated that oceanic precipitation features with lightning tended to be over 10 times larger and more stratiform than those over continents and suggested the hypothesis that some form of external forcing is acting in ways that lead to both larger features and stronger updrafts over tropical oceans. In this work, we evaluate this hypothesis by using reanalysis data to compare large‐scale vertical motion and thermodynamic data for radar precipitation features in archetypal land and ocean regimes in the Congo and Central Pacific. We then expand our study to the entire Tropical Rainfall Measuring Mission (TRMM) domain (35°S to 35°N) over all seasons. Over the ocean, there is a tendency for stronger large‐scale upward motion, linear organization of the convective region, and larger precipitation areas in systems with lightning. By comparison, over land, features with lightning tend to be smaller, in environments of higher instability, with little difference in large‐scale vertical motion. Expanding our analysis to 21 different regions, we highlight those in which seasonal synoptic patterns and water temperature gradients lead to distributions that are exceptions to the findings that ocean storms with lightning tend to be larger and more mature than land storms with lightning. These findings support the hypothesis that most land storms have updrafts sufficiently strong to develop lightning in their early growth stages, while ocean storms require large‐scale ascent and growth into mesoscale convective systems before convective scale updrafts become strong enough to provide the necessary conditions for lightning.
A High‐Energy Charge‐Separated State of 1.70 eV from a High‐Potential Donor–Acceptor Dyad: A Catalyst for Energy‐Demanding Photochemical Reactions
Authors: Lim Gary N. , Obondi Christopher O. , D'Souza Francis 
Published: August 2016

AbstractA high potential donor–acceptor dyad composed of zinc porphyrin bearing three meso‐pentafluorophenyl substituents covalently linked to C60, as a novel dyad capable of generating charge‐separated states of high energy (potential) has been developed. The calculated energy of the charge‐separated state was found to be 1.70 eV, the highest reported for a covalently linked porphyrin–fullerene dyad. Intramolecular photoinduced electron transfer leading to charge‐separated states of appreciable lifetimes in polar and nonpolar solvents has been established from studies involving femto‐ to nanosecond transient absorption techniques. The high energy stored in the form of charge‐separated states along with its persistence of about 50–60 ns makes this dyad a potential electron‐transporting catalyst to carry out energy‐demanding photochemical reactions. This type of high‐energy harvesting dyad is expected to open new research in the areas of artificial photosynthesis especially producing energy (potential) demanding light‐to‐fuel products.
Complete Transmetalation in a Metal–Organic Framework by Metal Ion Metathesis in a Single Crystal for Selective Sensing of Phosphate Ions in Aqueous Media
Authors: Asha K S , Bhattacharjee Rameswar , Mandal Sukhendu 
Published: August 2016

AbstractA complete transmetalation has been achieved on a barium metal–organic framework (MOF), leading to the isolation of a new Tb‐MOF in a single‐crystal (SC) to single‐crystal (SC) fashion. It leads to the transformation of an anionic framework with cations in the pore to one that is neutral. The mechanistic studies proposed a core–shell metal exchange through dissociation of metal–ligand bonds. This Tb‐MOF exhibits enhanced photoluminescence and acts as a selective sensor for phosphate anion in aqueous medium. Thus, this work not only provides a method to functionalize a MOF that can have potential application in sensing but also elucidates the formation mechanism of the resulting MOF.
Carbocatalysis in Liquid‐Phase Reactions
Authors: Su Dang Sheng , Wen Guodong , Wu Shuchang , Peng Feng , Schlögl Robert 
Published: August 2016

AbstractThere is broad interest in metal‐free catalysis for sustainable chemistry. Carbocatalysis is a “green” option for catalytic transformations in the gas phase as well as in the liquid phase. This is evident by the numerous reports on gas‐phase dehydrogenation and selective oxidation where carbon can be used as a successful alternative to metal oxide systems. Carbocatalysis for liquid‐phase reactions, especially for organic synthesis, is an emerging research discipline and has undergone rapid development in recent years. This Review provides a critical analysis on the state‐of‐the‐art of carbocatalysts for liquid‐phase reactions, with a focus on the underlying mechanisms as well as the advantages and limitations of metal‐free carbocatalysts.
Electrospun poly(hydroxybutyrate)/chitosan blend fibrous scaffolds for cartilage tissue engineering
Authors: Sadeghi Davoud , Karbasi Saeed , Razavi Shahnaz , Mohammadi Sajjad , Shokrgozar Mohammad Ali , Bonakdar Shahin 
Published: August 2016

ABSTRACTIn this study, polyhydroxybutyrate (PHB) was blended with chitosan (CTS), and electrospun in order to produce more hydrophilic fibrous scaffolds with higher mass loss rates for cartilage tissue engineering application. First, the effects of diverse factors on the average and distribution of fiber's diameter of PHB scaffolds were systematically evaluated by experimental design. Then, PHB 9 wt % solutions were blended with various ratios of CTS (5%, 10%, 15%, and 20%) using trifluoroacetic acid as a co‐solvent, and electrospun. The addition of CTS could decrease both water droplet contact angle from ∼74° to ∼67° and tensile strength from, ∼87 MPa to ∼31 MPa. According to the results, the scaffolds containing 15% and 20% CTS were selected as optimized scaffolds for further investigations. Mass loss percentage of these scaffolds was directly proportional to the amount of CTS. Chondrocytes attached well to the surfaces of these scaffolds. The findings suggested that PHB/CTS blend fibrous scaffolds have tremendous potentials for further investigations for the intended application. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44171.
Controlling micro‐ and nanofibrillar morphology of polymer blends in low‐speed melt spinning process. Part I. Profiles ofPLA/PVA‐filament parameters along the spinline
Authors: Tran Nguyen Hoai An , Brünig Harald , Heinrich Gert 
Published: August 2016

ABSTRACTThe profiles of PLA/PVA filament parameters (e.g., temperature, velocity, tensile stress, and apparent elongational viscosity) along the spinline in the low‐speed melt spinning process under various spinning conditions were investigated. Owing to the combination of the filament velocity and filament temperature measurements using laser doppler velocimetry (LDV) and infrared thermography, respectively, the fiber formation zone was determined. The length of the fiber formation zone obtained from filament velocity profilesis always shorter than that obtained from the filament temperature profiles(. Obviously, this unexpected phenomenon occurs for low spinning speeds due to the axial heat conduction effect of the filament along the spinline and the nonuniform radial temperature distribution through the cross‐sectional thick filament. Another remarkable finding is related to the Nusselt number which has been found as nearly constant along the spinline in the low‐speed melt spinning process. Thus, mathematical simulations of the filament temperature profiles will be simplified drastically. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2016,133, 44258.
Cyp3a11‐mediated testosterone‐6β‐hydroxylation decreased, while UGT1a9‐mediated propofol O‐glucuronidation increased, in mice with diabetes mellitus
Authors: Shi Rong , Wu Jiasheng , Meng Cong , Ma Bingliang , Wang Tianming , Li Yuanyuan , Ma Yueming 
Published: August 2016

AbstractThe db/db mouse is one of the most popular animal models for type 2 diabetes mellitus, but changes in the activities of important P450s and UGTs are still not completely clear. This study was designed to investigate the alterations of major hepatic cytochrome P450s and UDP‐glucuronyltransferase enzymes in db/db mice. Mouse liver microsomes (MLMs) were obtained from male db/db mice and their wild type littermates. After incubation of the substrates separately with MLMs, the samples were pooled and analysed by high‐throughput liquid chromatography–tandem mass spectrometry system for the simultaneous study of nine phase I metabolic reactions and three glucuronidation conjugation reactions to determine the activity of the metabolic enzymes. Compared with normal controls, the Clint estimate for testosterone‐6β‐hydroxylation was lower (46%) (p < 0.05), while the Vmax and Clint estimates for propofol O‐glucuronidation were 5‐fold higher (p < 0.01) in the liver microsomes from db/db mice. There was no significant difference in phase I metabolic reactions of phenacetin‐O‐deethylation, coumarin‐7‐hydroxylation, bupropion‐hydroxylation, omeprazole‐5‐hydroxylation, dextromethorphan‐O‐demethylation, tolbutamide‐4‐hydroxylation, chlorzoxazone‐6‐hydroxylation and midazolam‐1‐hydroxylation and in glucuronidation reactions of estradiol 3‐O‐glucuronidation, and 3‐azido‐3‐deoxythymidine glucuronidation. The data suggest that, in db/db mice, the activity of Cyp3a11, catalysing testosterone‐6β‐hydroxylation, decreased, while the activity of UGT1a9, catalysing propofol O‐glucuronidation, increased. Copyright © 2016 John Wiley & Sons, Ltd.
The excitation mechanism of btp2Ir(acac) in CBP host
Authors: Xiao‐Bo Zhang , Fu‐Xiang Wei 
Published: August 2016

AbstractWhether bis(2‐(2′‐benzo[4,5‐α]thienyl)pyridinato‐N,C3′)iridium(acetylacetonate) (btp2Ir(acac)) emission comes from carrier trapping and/or energy transfer, when doped in the 4,4′‐bis(N‐carbazolyl)biphenyl (CBP) host in organic light‐emitting devices, is not clear; therefore, the btp2Ir(acac) emission in CBP hosts was studied. In the red‐doped device, both N,N′‐bis(1‐naphthyl)‐N,N′‐diphenyl‐1.1′‐bipheny1–4‐4′‐diamine (NPB) and (1,1′‐biphenyl‐4′‐oxy)bis(8‐hydroxy‐2‐methylquinolinato)‐aluminum (BAlq) emission appeared, which illustrated that CBP excitons cannot be formed at two emissive layer (EML) interfaces in the device. In the co‐doped devices, NPB and BAlq emissions disappear and 1,4‐bis[2‐(3‐N‐ethylcarbazoryl)vinyl]benzene (BCzVB) emission appears, illustrating the formation of CBP excitons at two EML interfaces in these devices. The reason for this difference was analyzed and it was found that holes in the NPB layer could be made directly into the CBP host in the EML interface of the red‐doped device. In contrast, holes were injected into CBP host via the btp2Ir(acac)/BCzVB dopants in the co‐doped devices, which facilitated hole injection from the NPB layer to the EML, leading to the formation of CBP excitons at two EML interfaces in the co‐doped devices. Therefore, btp2Ir(acac) emission was caused by carrier trapping in the red‐doped device, while, in the co‐doped devices, it resulted from both carrier trapping and energy transfer from the CBP. Furthermore, it was revealed that the carrier trapping mechanism is less efficient than the energy transfer mechanism for btp2Ir(acac) excitation in co‐doped devices. In summary, our results clarified the excitation mechanism of btp2Ir(acac) in the CBP host.
Cohort study of mesenteric panniculitis and its relationship to malignancy
Authors: Buchwald P , Diesing L , Dixon L , Wakeman C , Eglinton T , Dobbs B , Frizelle F 
Published: August 2016

AbstractBackgroundMesenteric panniculitis (MP) is a rare condition that historically has been associated with the presence of malignancy. Paraneoplastic phenomena in general regress with cure and in most cases with treatment of the cancer. This study was undertaken to determine whether MP regressed with cancer treatment and cure.MethodsThis was a retrospective review of a database of all patients with MP confirmed on CT between 2003 and August 2015 at Christchurch Hospital. Patients were categorized as having malignant or non-malignant disease, and follow-up scans were assessed for remission of MP. Patients with malignancy were further categorized as having malignancy cured or not cured.ResultsA total of 308 patients were identified with possible MP; 135 were excluded as radiological appearances were not typical of MP (43 patients) or there was no follow-up CT (92). Of 173 patients (131 men) included, 75 (43·4 per cent) were diagnosed with malignancy. Follow-up imaging showed that 33 patients (19·1 per cent) had remission of MP, whereas 140 (80·9 per cent) had no remission. There was no difference in the rates of MP remission in the malignancy versus no malignancy groups (P = 1·000), or between groups in which malignancy was cured or not cured (P = 0·572). Nor was there any difference in the rates of MP remission in malignancy cured versus no malignancy groups (P = 0·524).ConclusionMP does not behave like a paraneoplastic phenomenon. The association with malignancy is most likely an epiphenomenon of the many CT images acquired for staging of cancer.
Retrospective analysis of 30-day mortality for emergency general surgery admissions evaluating the weekend effect
Authors: McCallum I J D , McLean R C , Dixon S , O'Loughlin P 
Published: August 2016

Abstract

Background
The weekend effect describes excess mortality associated with hospital admission on Saturday or Sunday. This study assessed whether a weekend effect exists for patients admitted for emergency general surgery.

Methods
Data for emergency general surgical admissions to National Health Service hospitals in the Northern Deanery in England between 2000 and 2014 were collected, including demographics, co-morbidities, diagnoses, operations undertaken and outcomes. The primary outcome of interest was in-hospital death within 30 days of admission. Cox regression analysis was undertaken with adjustment for co-variables.

Results
There were 12 100 in-hospital deaths within 30 days of admission (3·3 per cent). The overall 30-day mortality rate reduced significantly during the 15-year interval studied, from 5·4 per cent (2000–2004) to 4·0 per cent (2005–2009) and 2·9 per cent during 2010–2014 (P &lt; 0·001). There was no significant mortality difference for patients admitted at the weekend in adjusted Cox models (hazard ratio (HR) 1·00 for Saturday and 0·90 for Sunday, versus Wednesday). There was a significantly higher mortality for operations undertaken at the weekend (HR 1·15 for Saturday and 1·40 for Sunday; P = 0·021 and P &lt; 0·001 respectively). The significantly increased mortality that was evident for emergency surgery at the weekend compared with weekdays in 2000–2004 (HR 1·46 for Saturday and 1·55 for Sunday; both P &lt; 0·001); had reduced by 2010–2014, when the adjusted mortality risk was not significant (HR 1·18 for Saturday and 1·12 for Sunday).

Conclusion
During the past 15 years there has been a weekend effect in patients undergoing emergency general surgery based on day of operation, but not day of admission. Overall mortality for emergency general surgery has improved significantly, and in the past 5 years the increased mortality risk of weekend surgery has reduced.
Method validation and determination of lisdexamfetamine and amphetamine in oral fluid, plasma and urine by LC–MS/MS
Authors: Comiran Eloisa , Barreto Fabiano , Meneghini Leonardo Z. , Carlos Graciela , Fröehlich Pedro E. , Limberger Renata Pereira 
Published: August 2016

AbstractLisdexamfetamine (LDX) is a long‐acting prodrug stimulant indicated for the treatment of attention‐deficit/hyperactivity disorder and binge‐eating disorder symptoms. In vivo hydrolysis of LDX amide bond releases the therapeutically active d‐amphetamine (d‐AMPH). Since toxicological tests in biological samples can detect AMPH from the use of some legal medications, efficient methods are needed in order to correctly interpret the results. The aim of this study was to develop and validate an LC–MS/MS method for the simultaneous quantification of LDX and its main biotransformation product AMPH in human oral fluid, plasma and urine. Calibration curve range for both analytes was 1–128 ng/mL in oral fluid and plasma and 4–256 ng/mL in urine, being the lowest concentration the limit of quantification. Accuracy of the determined values of the target analytes for the five control levels ranged from 94.8 to 111.7% for oral fluid, from 91.3 to 100.2% for plasma and from 94.8 to 109.8% for urine. Imprecision for the five control levels did not exceeded 12.8% for oral fluid, 16.2% for plasma and 17.1% for urine. The method developed for the three matrices was validated and was also successfully applied to assess real samples, showing for the first time the detection of LDX in oral fluid.
Initial Molecular Recognition Steps of McjA Precursor during Microcin J25 Lasso Peptide Maturation
Authors: Assrir Nadine , Pavelkova Anna , Dazzoni Régine , Ducasse Rémi , Morellet Nelly , Guittet Eric , Rebuffat Sylvie , Zirah Séverine , Li Yanyan , Lescop Ewen 
Published: August 2016

AbstractMicrocin J25 (MccJ25) has emerged as an excellent model to understand the maturation of ribosomal precursor peptides into the entangled lasso fold. MccJ25 biosynthesis relies on the post‐translational modification of the precursor McjA by the ATP‐dependent protease McjB and the lactam synthetase McjC. Here, using NMR spectroscopy, we showed that McjA is an intrinsically disordered protein without detectable conformational preference, which emphasizes the active role of the maturation machinery on the three‐dimensional folding of MccJ25. We further showed that the N‐terminal region of the leader peptide is involved in interaction with both maturation enzymes and identified a predominant interaction of V43–S55 in the core McjA sequence with McjC. Moreover, we demonstrated that residues K23–Q34 in the N‐terminal McjA leader peptide tend to adopt a helical conformation in the presence of membrane mimics, implying a role in directing McjA to the membrane in the vicinity of the lasso synthetase/export machinery. These data provide valuable insights into the initial molecular recognition steps in the MccJ25 maturation process.