bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cobalt(II)‐based ethylene dimerization catalysts with silicon‐bridged diphosphine ligands
Authors: Wei Wei , Yu Buwei , Alam Fakhre , Huang Yongwang , Cheng Shaoling , Jiang Tao 
Published: October 2018

A series of ligands and cobalt complexes were synthesized and characterized using NMR spectroscopy, elemental analysis and single‐crystal X‐ray diffraction. Complex C1 [CoCl2{N‐(2,6‐diisopropylphenyl)‐N‐[(diphenylphosphino)dimethylsilyl]‐1,1‐diphenylphosphine}] features a monomeric structure with κ2 coordination of the silicon‐bridged diphosphine ligand to the cobalt center. Using dried methylaluminoxane (DMAO) and AlEt3 as co‐catalysts and methylcyclohexane as solvent, the Co(II) complex proved to be moderately active and highly selective for ethylene dimerization. The effects of ligand structure, catalyst loading, reaction temperature, Al/Co molar ratio, DMAO/AlEt3 molar ratio and reaction time were investigated with respect to the catalytic activity and product selectivity of ethylene dimerization. Cobalt complex C1 exhibited moderate catalytic activity of 2.3 × 105 g (molCo)−1 h−1, with 100% selectivity towards C4 (87% 1‐C4 in the C4 fraction).
Reaction kinetics and curing behavior of epoxies for use in a combined selective laser beam melting process of polymers
Authors: Wudy K. , Budde T. 
Published: October 2018

ABSTRACTSelective laser beam melting also known as selective laser sintering (SLS) of polymers is an additive manufacturing process, which enables the production of functional components. Additive manufacturing has its strength in areas where conventional manufacturing methods, such as injection molding, reach their limitations. Unfortunately, the SLS process is restricted regarding the materials that can be processed. This work clears the ground for multimaterial SLS parts, locally reinforced with thermosets. To introduce thermoset resins into the SLS process, the time–temperature curing of the resins have to be understood in order to assess the process behavior. The time–temperature behavior of the used resins is of main importance because of high temperature in the building chamber during laser sintering and long build time up to hours. For Polyamide 12, a standard material in SLS, the building chamber temperature is approximately 170 °C. Therefore, the used resin has to show a specific curing behavior at the building chamber temperature in SLS. Two epoxies, Araldite GY 764 and Araldite GY 793, are analyzed using isothermal and nonisothermal differential scanning calorimetry (DSC) in order to determine whether these resins can be used in SLS or not. Different approaches to model the curing behavior are applied, including the Kissinger method, the Ozawa–Flynn–Wall analysis, and the DiBenedetto equation. The curing behavior of the analyzed resins were finally compared to temperature profiles during SLS to estimate the curing behavior of these systems in SLS. At a medium building chamber temperature of 160 °C, both thermosets show a suitable curing behavior, because of a degree of cure that ranges between 0.15 and approximately 0.6 for 2 up to 10 min. Thus, the curing reaction starts after applying the resin on the powder bed surface and reaches a higher level after approximately 10 layers, assuming a layer time of 1 min. © 2018 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 46850.
Continuous and high throughput production of alginate fibers using co‐flow in a millifluidic T‐junction
Authors: Pendyala G. , Bithi S. S. , Vanapalli S. A. , Fernandes G. E. 
Published: October 2018

ABSTRACTWe present a new technique for continuous production of alginate fibers using off‐the‐shelf millifluidic components and syringe pumps. The components are quickly assembled to form a T‐junction to deliver co‐flowing streams of sodium alginate and calcium chloride allowing formation of hydrogel fibers in the exit channel. We vary the flow rates of the two streams, calcium chloride concentrations and length of exit channel and identify conditions where fibers of uniform and nonuniform thickness are produced. We find that uniform fibers can be produced at a maximum total flow rate of 10 mL min−1. As expected, for uniform fibers, we observe that the fiber diameter increases with increase in alginate solution flow rate, and we propose a simple model that predicts the fiber diameter as a function of flow rate ratio. We investigate the source of fiber nonuniformity and explain it using an empirical model that involves crosslinking time and gel strength. Our approach features easy device assembly and operation and enables continuous fiber production without clogging risks. Fiber production rates in the order of 10 m min−1 are achievable using our approach. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47120.
Fabrication of dual‐layer poly(styrene‐b‐4‐vinyl pyridine)–poly(vinylidene fluoride) membranes with tailored pore sizes under 10 nm via surface quaternization
Authors: Su Y. , Liu Y. , Liu T. , Wang X. 
Published: October 2018

ABSTRACTBlock copolymer membranes can be applied to precise size‐based separation because of their highly ordered surface morphology and adjustable pore sizes. However, there is a lower limit of the scale of block copolymer self‐assembly; this makes it a challenge to tailor the pore size down to below 10 nm. In this study, poly(styrene‐b‐4‐vinyl pyridine) membranes were modified to quaternized selective layers with pores smaller than 10 nm and were supported by poly(vinylidene fluoride) hollow fibers as the substrate to provide a high mechanical strength. Two reactants, methyl iodide and 2‐chloroacetamide, were used in the quaternization. With this one‐step chemical modification, the molecular weight cutoff was reduced from 190 to 8 kDa, and the surface pore sizes were narrowed down from 20–30 to 3 nm; this bridged the gap of tailored pore sizes down to below 10 nm. Such membranes are promising candidates for low‐molecular‐weight separation with high resolution. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47137.
Improvement in mechanical and hygroscopic properties of modified SA fiber crosslinking with PEGDE
Authors: Meng Chihan , Li Huitao , Zhu Guofu , Cao Shiwen , Zhang Hong , Liu Yuanfa , Guo Jing 
Published: October 2018

ABSTRACTModified sodium alginate (mSA) fiber is prepared through the wet spinning process using poly(ethylene glycol) diglycidyl ether (PEGDE, the molecular weight of PEGDE is 400) as the crosslinking agent to improve the mechanical and hygroscopic properties. Flowing property of the spinning solution and properties of the mSA fiber are characterized by DV‐C digital viscometer, single fiber electronic tensile strength tester and other instruments. Results show that viscosity of the spinning solution dropped firstly, then increased and decreased lastly with increasing PEGDE content in mSA fiber. The optimal value of the tensile strength of mSA fiber is 2.47 cN/dtex increasing by 64.67% compared to pure SA fiber. Both the crosslinking degree and crystallinity of mSA fiber rise first and then descended with the increase of PEGDE content. The hydroscopicity of mSA fiber increase from 30.5% to 70.9% at 20 wt % PEGDE in mSA fiber. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47155.
Multiple Sources for Sertoli Cells and Two Sertoli Phenotypes in the Adult Elasmobranch Testis: Insight from Two Species Belonging to Different Orders
Authors: McClusky Leon Mendel 
Published: October 2018

ABSTRACTFindings presented here for the chondrichthyans Prionace glauca and Isurus oxyrinchus show that the assembly of the spermatocyst and it's attached collecting duct are seamlessly connected developmental phenomena. The cyst's somatic cell component (i.e., Sertoli cells, SCs) and the duct's constituent cells derive both from a common precursor cell type (typically a large oblong cell) found among the A‐spermatogonia in the folliculogenic region. Novel findings show that the co‐developing collecting duct itself serves also as a source of either normal‐looking or basophilic atypical SCs (aSCs), depending on whether the duct–cyst transition remains mitotically active and open, or is sealed. The aSCs arise from accumulating slender basophilic cells at the duct–cyst interface after which the newly formed cyst is sealed. Quantitative analysis of the latter in P. glauca revealed a correlation between the appearance of this aSC in immature cysts and the degenerated testicular condition that displays a gradient of multinucleate cell (MNC) death among spermatogonial cysts. Findings seem to implicate these aSCs in the life–death balance in mature spermatogonial cohorts downstream in the spermatogenic sequence, rather than in newly formed cysts that exhibit low rates of apoptosis. Photomicrographs of developing spermatogonial cysts showing several aSCs interspersed among cytoplasmically linked spermatogonia that are proliferating or have died, seem to suggest that these small SCs may be involved in confining MNC death to a given cyst region under conditions of subthreshold levels of apoptosis such as to ensure cyst recovery in immature spermatogonial cysts. Anat Rec, 301:1944–1954, 2018. © 2018 Wiley Periodicals, Inc.
Co‐administration of nuciferine reduces the concentration of metformin in liver via differential inhibition of hepatic drug transporter OCT1 and MATE1
Authors: Li Liping , Lei Hongmei , Wang Wei , Du Weijuan , Yuan Jingqun , Tu Meijuan , Zhou Hui , Zeng Su , Jiang Huidi 
Published: October 2018

AbstractNuciferine (NF), one of the main and effective components in Nelumbo nucifera Gaertn. leaf extracts, is a promising drug candidate for the treatment of obesity‐related diseases, while metformin is a first line therapeutic drug for type 2 diabetes mellitus. Since nuciferine and metformin are likely to be co‐administered, the aim of the present study was to evaluate whether co‐administration of nuciferine would influence the liver (target tissue) distribution and the anti‐diabetic effect of metformin by inhibiting hepatic organic cation transporter 1 (OCT1) and multidrug and toxin extrusion 1 (MATE1). The data demonstrated that nuciferine significantly reduced metformin accumulation in MDCK cells stably expressing human OCT1 (MDCK‐hOCT1) or hMATE1 (MDCK‐hMATE1), and primary cultured mouse hepatocytes. Furthermore, the presence of nuciferine in the basal compartment caused a concentration‐dependent reduction of intracellular metformin accumulation in MDCK‐hOCT1/hMATE1 cell monolayers. Compared with the metformin treatment‐alone group, co‐administration of nuciferine (40 mg/kg) markedly reduced the metformin concentration in mouse livers at 30 and 60 min after a single oral dose of metformin (200 mg/kg), and subsequently impaired the glucose‐lowering effect of metformin (200 mg/kg), but the glucose‐lowering effect became no different at 90 and 120 min. Therefore, nuciferine influenced the liver concentration and glucose‐lowering effect of metformin only for a period of time after dose, administration of nuciferine and metformin with an interval might prevent the drug–drug interaction mediated by OCT1 and MATE1.
Bioprosthetic aortic valve leaflet disruption with high energy electrocautery to prevent coronary artery obstruction during valve‐in‐valve transcatheter aortic valve replacement
Authors: Nelson Bradley C. , Chadderdon Scott , Song Howard , Zahr Firas E. 
Published: October 2018

AbstractTranscatheter aortic valve replacement (TAVR) is well‐established for the treatment of bioprosthetic aortic valve stenosis (AS) in high surgical risk patients. Coronary artery obstruction from displacement of the bioprosthetic valve leaflets during valve‐in‐valve (VIV) TAVR is a rare, but potentially fatal, complication. Recently, the bioprosthetic aortic scallop intentional laceration to prevent iatrogenic coronary artery obstruction (BASILICA) procedure was developed as a method for disrupting bioprosthetic leaflets in patients undergoing VIV TAVR at high risk for coronary obstruction. This case describes a successful VIV TAVR utilizing a simplified concept of the BASILICA technique in a patient where the full procedure could not be completed.
Splenic mass in a case of CALR‐mutated essential thrombocythemia
Authors: Imashuku Shinsaku , Kotani Shinichi , Hinami Junsuke , Nishimura Keisuke 
Published: October 2018

Key Clinical MessageWe report here an intrasplenic large mass in an elderly case of essential thrombocythemia (ET)‐myelofibrosis. Laparoscopic splenectomy revealed extramedullary hematopoiesis (EMH) and a type 1 CALR gene mutation (CALR‐c.1092_1143del52) in the splenic mass. It remains to be determined if CALR‐mutated ET has an increased tendency to develop mass‐forming EMH.
Poly(4‐styrene sulfonic acid) to Disperse Graphene for Applications in Lithium‐Sulfur Batteries
Authors: Cheng Wei‐Ju , Chang Shinn‐Jen , Cho Chuan‐Sheng , Li Chia‐Chen 
Published: October 2018

AbstractThe use of poly(4‐styrene sulfonic acid) (PSSA) to effectively disperse graphene in an aqueous sulfur (S) cathode slurry is proposed, and the cell performance of the resulting Li−S battery is investigated and compared to that of the battery prepared by adding as‐received graphene. The addition of PSSA improves not only the dispersion of the as‐received graphene, but also the homogeneity of the constituents in the S cathode slurry; accordingly, better electronic and ionic conductivities are obtained. The electrical impedance of the cell constructed using the S cathode with the as‐received graphene is greatly reduced from 142.0 to 14.6 Ω when PSSA is added during the preparation of the cathode. Moreover, the addition of the PSSA‐dispersed graphene to the S cathode significantly improves the capacity, cycle life, and coulombic efficiency during the charge‐discharge process, since PSSA increases the contact between the dispersed graphene and the insulated S powder.
Normal diffusivity of the domestic feline brain
Authors: Barry Erica F. , Cerda‐Gonzalez Sofia , Luh Wen‐Ming , Daws Richard E. , Raj Ashish , Johnson Philippa J. 
Published: October 2018

AbstractDiffusion magnetic resonance imaging (MRI) provides useful information about neuroanatomy and improves detection of neuropathology. As yet, a comprehensive evaluation of the diffusivity parameters within the feline brain has not been documented. In this study, we anesthetized and performed in vivo MRI on the brain of eight neurologically normal felines. A T1‐weighted structural sequence with a resolution of 0.5 mm3 and a parallel diffusion weighted sequence with 61 directions and a resolution of 1.5 mm3 was obtained. After correction and processing the diffusion brain data were parcellated into 151 regions of interest using previously published priors. These regions were grouped according to their lobar location within the brain (frontal, occipital, temporal, parietal, thalamus, midbrain, cerebellum, and white matter). The mean and standard deviation of fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD), and axial diffusivity (AD) for these 151 individual regions and lobar groups were calculated and averaged across participants, creating a comprehensive distribution range of diffusion tensor values. When regions were statistically evaluated, white matter had significantly higher FA and RD and lower AD and MD diffusivity parameters when compared to other regions. Additionally, thalamic regions had significantly higher FA values than parietal and occipital regions. This information will not only help inform feline neuroanatomy but also will serve as a reference standard for future feline neuroimaging studies.
Unique hues and principal hues
Authors: Fairchild Mark D. 
Published: October 2018

AbstractThis note examines the different concepts of encoding hue perception based on four unique hues (like NCS) or five principal hues (like Munsell). Various sources of psychophysical and neurophysiological information on hue perception are reviewed in this context and the essential conclusion that is reached suggests there are two types of hue perceptions being quantified. Hue discrimination is best quantified on scales based on five, equally spaced, principal hues while hue appearance is best quantified using a system based on four unique hues as cardinal axes. Much more remains to be learned.
Interband Electron Pairing for Superconductivity from the Breakdown of the Born‐Oppenheimer Approximation
Authors: Whangbo Myung‐Hwan , Deng Shuiquan , Köhler Jürgen , Simon Arndt 
Published: October 2018

AbstractThe origin of interband electron pairing, responsible for enhancing superconductivity, and the factors controlling its strength were examined. We show that interband electron pairing is a natural consequence of breaking down the Born‐Oppenheimer approximation during electron‐phonon interactions. Its strength is determined by the pair‐state excitations around the Fermi surfaces that take place to form a superconducting state. Fermi surfaces favorable for the pairing were found, and the implications of this observation are discussed.
Effectiveness and safety of rivaroxaban vs. warfarin in patients with non‐valvular atrial fibrillation and heart failure
Authors: Martinez Brandon K. , Bunz Thomas J. , Eriksson Daniel , Meinecke Anna‐Katharina , Sood Nitesh A. , Coleman Craig I. 
Published: October 2018

AbstractAimsHeart failure (HF) is a common co‐morbidity in non‐valvular atrial fibrillation (NVAF) patients and a potent risk factor for stroke, bleeding, and a decreased time‐in‐therapeutic range with warfarin. We assessed the real‐world effectiveness and safety of rivaroxaban and warfarin in NVAF patients with co‐morbid HF.Methods and resultsUsing US Truven MarketScan Commercial and Medicare supplemental database claims data from 11/2011 to 12/2016, we identified oral anticoagulant (OAC)‐naïve NVAF patients with HF (International Classification of Diseases, 10th Revision codes of I50 or I09.81) and ≥12 months of insurance coverage prior to the qualifying OAC dispensing. Rivaroxaban users (20 or 15 mg once daily) were 1:1 propensity score matched to warfarin users, with residual absolute standardized differences <0.1 being achieved for all covariates after matching. Patients were followed up until an event, OAC discontinuation/switch, insurance disenrolment, or end of follow‐up. Rates [events per 100 person‐years (PYs) of follow‐up] for stroke or systemic embolism and major bleeding (using the Cunningham algorithm) were compared between the matched cohorts using Cox proportion hazard regression and reported as hazard ratios (HRs) with 95% confidence intervals (CIs). We matched 3418 rivaroxaban (32% receiving the reduced dose) and 3418 warfarin users with NVAF and HF with a median (interquartile range) available follow‐up of 1.4 (0.6, 2.5) years. Median age was 74 (63, 82) years, and median CHA2DS2‐VASc and HASBLED scores were 4 (3, 5) and 2 (2, 3). Common HF medications included beta‐blockers (64%), angiotensin‐converting enzyme inhibitors or angiotensin receptor blockers (62%), loop diuretics (46%), digoxin (11%), and aldosterone receptor antagonists (10%). The hazard of developing stroke or systemic embolism (0.98 events/100PY vs. 1.28 events/100PY; HR = 0.82, 95% CI = 0.47–1.44), ischaemic stroke (0.70 events/100PY vs. 1.02 events/100PY; HR = 0.77, 95% CI = 0.41–1.46), or major bleeding (3.86 events/100PY vs. 4.23 events/100PY; HR = 0.98, 95% CI = 0.73–1.31) was not found to be different between rivaroxaban and warfarin users. Intracranial haemorrhage was infrequent in both cohorts and numerically less with rivaroxaban (0.27 events/100PY vs. 0.36 events/100PY; HR = 0.73, 95% CI = 0.25–2.08).ConclusionsEffectiveness and safety of rivaroxaban vs. warfarin are sustained in NVAF patients with co‐morbid HF treated in routine practice. The general consistency between this real‐world study and those from phase III randomized trial data of rivaroxaban should provide additional reassurance to clinicians regarding the use of rivaroxaban in NVAF patients with HF.
Fluvial dynamics and 14C‐10Be disequilibrium on the Bolivian Altiplano
Authors: Hippe Kristina , Gordijn Tiemen , Picotti Vincenzo , Hajdas Irka , Jansen John D. , Christl Marcus , Vockenhuber Christof , Maden Colin , Akçar Naki , Ivy‐Ochs Susan 
Published: October 2018

AbstractDetermining sediment transfer times is key to understanding source‐to‐sink dynamics and the transmission of environmental signals through the fluvial system. Previous work on the Bolivian Altiplano applied the in situ cosmogenic 14C‐10Be‐chronometer to river sands and proposed sediment storage times of ~10–20 kyr in four catchments southeast of Lake Titicaca. However, the fidelity of those results hinges upon isotopic steady‐state within sediment supplied from the source area. With the aim of independently quantifying sediment storage times and testing the 14C‐10Be steady‐state assumption, we dated sediment storage units within one of the previously investigated catchments using radiocarbon dating, cosmogenic 10Be‐26Al isochron burial dating, and 10Be‐26Al depth‐profile dating. Palaeosurfaces appear to preserve remnants of a former fluvial system, which has undergone drainage reversal, reduction in catchment area, and local isostatic uplift since ~2.8 Ma. From alluvium mantling the palaeosurfaces we gained a deposition age of ~580 ka, while lower down fluvial terraces yielded ≤34 ka, and floodplains ~3–1 ka. Owing to restricted channel connectivity with the terraces and palaeosurfaces, the main source of channel sediment is via reworking of the late Holocene floodplain. Yet modelling a set of feasible scenarios reveals that floodplain storage and burial depth are incompatible with the 14C‐10Be disequilibrium measured in the channel. Instead we propose that the 14C‐10Be offset results from: (i) non‐uniform erosion whereby deep gullies supply hillslope‐derived debris; and/or (ii) holocene landscape transience associated with climate or human impact. The reliability of the 14C‐10Be chronometer vitally depends upon careful evaluation of sources of isotopic disequilibrium in a wide range of depositional and erosional landforms in the landscape. © 2018 John Wiley & Sons, Ltd.
Critical review: Grand challenges in assessing the adverse effects of contaminants of emerging concern on aquatic food webs
Authors: Nilsen Elena , Smalling Kelly L. , Ahrens Lutz , Gros Meritxell , Miglioranza Karina S.B. , Picó Yolanda , Schoenfuss Heiko L. 
Published: October 2018

Abstract

Much progress has been made in the past few decades in understanding the sources, transport, fate, and biological effects of contaminants of emerging concern (CECs) in aquatic ecosystems. Despite these advancements, significant obstacles still prevent comprehensive assessments of the environmental risks associated with the presence of CECs. Many of these obstacles center around the extrapolation of effects of single chemicals observed in the laboratory or effects found in individual organisms or species in the field to impacts of multiple stressors on aquatic food webs. In the present review, we identify 5 challenges that must be addressed to promote studies of CECs from singular exposure events to multispecies aquatic food web interactions. There needs to be: 1) more detailed information on the complexity of mixtures of CECs in the aquatic environment, 2) a greater understanding of the sublethal effects of CECs on a wide range of aquatic organisms, 3) an ascertaining of the biological consequences of variable duration CEC exposures within and across generations in aquatic species, 4) a linkage of multiple stressors with CEC exposure in aquatic systems, and 5) a documenting of the trophic consequences of CEC exposure across aquatic food webs. We examine the current literature to show how these challenges can be addressed to fill knowledge gaps. Environ Toxicol Chem 2019;38:46–60. © 2018 SETAC