bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermoplastic vulcanizate nanocomposites based on polyethylene/reclaimed rubber: A correlation between carbon nanotube dispersion state and electrical percolation threshold
Authors: Vahidifar Ali , Esmizadeh Elnaz , Elahi Maryam , Ghoreishy Mir Hamid Reza , Naderi Ghasem , Rodrigue Denis 
Published: April 2019

ABSTRACTA three‐step melt blending process was utilized to produce linear low‐density polyethylene (LLDPE)/reclaimed rubber (RR)/carbon nanotube (CNT) nanocomposites in the presence of maleic anhydride grafted polyethylene as a compatibilizer. The effect of LLDPE/RR ratio and CNT content on the morphological, thermal, mechanical, and rheological behavior of these dynamically vulcanized LLDPE/RR nanocomposites were investigated. The morphological study showed that the RR was dispersed in the LLDPE matrix, and CNT addition led to an improved morphology as smaller RR sizes inside LLDPE were observed. The mechanical results revealed that increasing the RR content decreased the hardness, modulus of elasticity, and elongation at break while CNT improved the tensile properties and other mechanical properties. The differential scanning calorimeter analysis showed that the CNT improved the LLDPE crystallization by acting as nucleation agents. Dynamic mechanical analysis showed higher storage modulus and lower loss factor as compared to the neat blend due to mobility restrictions of the polymer chains induced by the presence of CNT. For the conditions studied, the electrical percolation threshold was found to occur at a very low CNT concentration (about 1 wt %) compared to the literature because of the specific structure produced leading to CNT residing in the LLDPE matrix and at the interface between both polymeric phases. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47795.
Synergistic effects of surface grafting with heparin and addition of poly(d,l‐lactide) microparticles on properties of poly(l‐lactide) single crystals scaffolds
Authors: Bakry Ahmed 
Published: April 2019

ABSTRACTMixtures of heparin grafted poly(l‐lactide) single crystals (Hep‐PLLAsc) and poly(d,l‐lactide) (PDLLA) microparticles are used for assembling hydrophilic and cytocompatible three‐dimensional tissue engineering scaffolds simply by compression molding/salt leaching technique. PLLA is grafted with heparin to promote its surface cytocompatability, while PDLLA is added to reinforce the scaffolds. PLLAsc are aminolyzed with tetraethylenepentamine (13‐atom spacer) to generate sterically accessible amino groups at the surface allowing the covalent attachment of heparin by aqueous carbodiimide chemistry. Morphological and compressive strength studies manifest the integrity and compactness of scaffolds. Toluidine blue assay assures the consistency of heparin distribution throughout the scaffolds, which is in contrary to the conventional grafting reactions by immersing the scaffold in heparin solution. The scaffolds applicability is examined by fibroblast cells seeding experiments. Contrary to pristine scaffolds, Hep‐PLLAsc scaffolds display a hydrophilic and cytocompatible interface for cell adhesion, spreading, growth, and migration. Therefore, combining presurface grafted PLLAsc with PDLLA microparticles could offer durable scaffolds exhibiting bioactive interface and controllable spatial distribution of the grafted biomacromolecules. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47797.
Adhesion properties of poly(methylmethacrylate‐co‐n‐butylmethacrylate) copolymers in stent coatings
Authors: Gagliardi Mariacristina 
Published: April 2019

ABSTRACTThis work explores the adhesion properties of polymer solutions and thin coatings obtained by different‐composition poly(methylmethacrylate‐co‐n‐butylmethacrylate) copolymers. Surface wettability, work of adhesion, and work of spreading are calculated for solutions. Increasing amounts of n‐butylmethacrylate lead to higher values of work of adhesion, measured over two stent‐like flat surfaces (AISI 316L and pyrolytic carbon). The same moiety induces the solution viscosity increase and the decrease of the work of spreading and allows obtaining more homogeneous coatings. Adhesion of thin coatings is tested in dry (cross‐cut test) and wet (immersion) conditions. Adhesion tests of coatings obtained by solvent casting reflect thermodynamic parameters evaluated for solutions. Coatings show better strength in cross‐cut tests and a prolonged adhesion in wet conditions by raising the n‐butylmethacrylate fraction. The same trends are confirmed in commercial devices. In conclusion, the study of thermodynamic solution/substrate interactions can explain coating properties. The proposed approach is worthwhile to improve deposition procedures based on polymer solutions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47814.
Preparation and performance of a composite gel as a dust suppressant for coal transportation and storage
Authors: Zhou Gang , Ding Jianfei , Sun Jian , Wang Yuying 
Published: April 2019

ABSTRACTIn the process of coal transportation and storage, a large amount of dust is inevitably generated, which seriously threatens the health of coal miners and causes the waste of resources. How to prevent and control the dust generated during coal transportation and storage is a key issue of coal mine occupational safety research. In this study, sodium alginate is reacted with 2‐acrylamide‐2‐methylpropanesulfonic acid, and the resulting intermediate is graft copolymerized with acrylic acid to prepare an environment friendly dust suppressant product suitable for coal transportation and storage. The microscopic reaction and structure of the product are analyzed by infrared spectroscopy, X‐ray photoelectron spectroscopy, thermogravimetric analysis, and scanning electron microscopy. The optimal synthesis conditions have been obtained by taking the strength of the coking coal as the single factor experiment evaluation index. Through the research on the related properties of the dust suppressant, it is found that this dust suppressant has excellent performance and an obvious dust suppression effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47819.
Aromaticity‐promoted C−F Bond Activation in Rhodium Complex: A Facile Tautomerization
Authors: Shen Ting , Xie Qiong , Li Yuanyuan , Zhu Jun 
Published: April 2019

AbstractFluorine is the most electronegative element in the periodic table. Thus, activation of the carbon–fluorine (C−F) bond, the strongest single bond to carbon, has attracted considerable interest from both experimentalists and theoreticians. In comparison with numerous approaches to activate C−F bonds, the aromaticity‐promoted method is less developed. Herein, we demonstrate that the C−F bond activation could be achieved by a facile tautomerization, benefitting from aromaticity, which can stabilize both the transition states and products. Our findings highlight an important application of aromaticity in the C−F bond activation, providing experimentalists with an alternative approach to activate C−F bonds.
Catalytic Reduction of Cyclic Ethers with Hydrosilanes
Authors: Park Sehoon 
Published: April 2019

AbstractCatalytic reductive transformations of ethers as a synthetic building block are an important class of chemical reactions because a range of essential chemical feedstocks and fuels in contemporary life can be prepared through the key step of ethereal C−O bond cleavage of cellulosic biomass. Although conventional stoichiometric and catalytic methods for sp2‐ and sp3‐C−O bond cleavage of linear ethers and alcohols with hydrosilanes are well established, silylative ring opening of cyclic ethers has been less highlighted in this context. This review outlines catalytic systems for the silylative reduction of a range of cyclic ethers, including epoxides and sugars, leading to the corresponding alcohols and/or hydrocarbons. The chemical reactivity and selectivity of these ring‐opening catalytic processes are discussed with respect to the type of substrates; the representative catalytic working modes are also described.
Electrophoretic Deposition for Lithium‐Ion Battery Electrode Manufacture
Authors: Lalau Cornel C. , Low Chee T. John 
Published: April 2019

AbstractElectrophoretic deposition (EPD) has received increasing attention as an alternative manufacturing approach to slurry casting for the production of battery and supercapacitor electrodes. This process is of relevance for industrial scalability as evidently seen in the current electrophoretic paints industry. Nevertheless, the reported work so far have only concentrated on thin films of electrophoretically deposited electrodes for energy storage. Here, the electrochemical performance of thick films (up to tens of μm) as lithium‐ion battery electrodes produced by EPD is reported. A commercially sourced LiN1/3M1/3C1/3O2 (5 to 25 μm particle size) was used in this exemplary investigation. This work shows the production of binder‐free high density active material (>90 %) electrodes. Coin cells were assembled and the battery performance was measured. Tests included: cyclic voltammetry, C‐rate vs capacity, battery cycling and electrochemical impedance spectroscopy. Other investigations also studied: colloidal electrolyte formulation, electrode manufacture, microstructure characterisation and elemental mapping analysis. In short, EPD electrode manufacture can be applied as a platform technology for any battery and supercapacitor material, and the reported manufacturing processes and methodologies represent direct relevance to produce energy storage electrodes useful to practical applications.
Contemporary prevalence of carotid stenosis in patients presenting with ischaemic stroke
Authors: Cheng S F , Brown M M , Simister R J , Richards T 
Published: April 2019

Abstract

Background
Carotid stenosis is a common cause of ischaemic stroke and transient ischaemic attack (TIA). Despite rising recognition and centralization of stroke services there has been a decline in interventions for carotid stenosis in recent years. The aim of this study was to determine the current prevalence and management of carotid stenosis in the UK.

Methods
This was a 1-year prospective observational study of consecutive patients presenting with ischaemic stroke, TIA or ischaemic retinal artery occlusion to a central London hyperacute stroke unit. Patients with significant carotid stenosis, defined as atherosclerotic narrowing of 50 per cent or greater, underwent multidisciplinary team (MDT) discussion to determine the cause of stroke/TIA and classify carotid stenosis as symptomatic or incidental.

Results
In total, 2707 patients were seen; half had an ischaemic event and the majority had carotid imaging (1252 of 1444). Carotid stenosis of at least 50 per cent was seen in 238 (prevalence 19·0 (95 per cent c.i. 16·6 to 21·4) per cent). Patients with significant carotid stenosis were more likely to have hypertension, hypercholesterolaemia, diabetes and ischaemic heart disease. Carotid stenosis was deemed symptomatic in 99 patients (7·9 (6·3 to 9·5) per cent); of these, 17 had carotid occlusion, 17 were unfit for surgery and 58 patients were referred for carotid intervention. Among 139 patients with asymptomatic stenosis, 75 had carotid stenosis ipsilateral to the stroke but, after MDT discussion, the cause was deemed to be atrial fibrillation (32), small-vessel disease (15), another determined cause (5), or not determined owing to atypical imaging or clinical presentation.

Conclusion
Carotid stenosis is common, affecting one in five patients presenting with stroke or TIA. Careful MDT discussion may avoid unnecessary intervention and should be the standard of care.
Survival after radiotherapy versus radical cystectomy for primary muscle‐invasive bladder cancer: A Swedish nationwide population‐based cohort study
Authors: Häggström Christel , Garmo Hans , de Luna Xavier , Van Hemelrijck Mieke , Söderkvist Karin , Aljabery Firas , Ströck Viveka , Hosseini Abolfazl , Gårdmark Truls , Malmström Per‐Uno , Jahnson Staffan , Liedberg Fredrik , Holmberg Lars 
Published: April 2019

AbstractBackgroundStudies of survival comparing radical cystectomy (RC) and radiotherapy for muscle‐invasive bladder cancer have provided inconsistent results and have methodological limitations. The aim of the study was to investigate risk of death after radiotherapy as compared to RC.MethodsWe selected patients with muscle‐invasive urothelial carcinoma without distant metastases, treated with radiotherapy or RC from 1997 to 2014 in the Bladder Cancer Data Base Sweden (BladderBaSe) and estimated absolute and relative risk of bladder cancer death and all‐cause death. In a group of patients, theoretically eligible for a trial comparing radiotherapy and RC, we calculated risk difference in an instrumental variable analysis. We have not investigated chemoradiotherapy as this treatment was not used in the study time period.ResultsThe study included 3 309 patients, of those 17% were treated with radiotherapy and 83% with RC. Patients treated with radiotherapy were older, had more advanced comorbidity, and had a higher risk of death as compared to patients treated with RC (relative risks of 1.5‐1.6). In the “trial population,” all‐cause death risk difference was 6 per 100 patients lower after radiotherapy at 5 years of follow‐up, 95% confidence interval −41 to 29.Conclusion(s)Patient selection between the treatments make it difficult to evaluate results from conventionally adjusted and propensity‐score matched survival analysis. When taking into account unmeasured confounding by instrumental variable analysis, no differences in survival was found between the treatments for a selected group of patients. Further clinical studies are needed to characterize this group of patients, which can serve as a basis for future comparison studies for treatment recommendations.
Toxoplasmosis as a cause of life‐threatening respiratory distress in a dog receiving immunosuppressive therapy
Authors: Pepper Amy , Mansfield Caroline , Stent Andrew , Johnstone Thurid 
Published: April 2019

Key Clinical MessageDisseminated toxoplasmosis is a potentially fatal complication in dogs receiving immunosuppressive therapy, particularly if multiple immunosuppressive drugs are used. Toxoplasmosis should be considered if signs of acute respiratory or hepatic disease develop, and diagnosis would rely on demonstration of organisms via cytology or PCR rather than a single time‐point serological assay.
Malignant epidural spinal cord compression secondary to testicular cancer (mixed choriocarcinoma and seminoma) in the immediate post radical orchidectomy period
Authors: Mukendi Alain Mwamba , Friedman Robin , Ismail Abdullah 
Published: April 2019

Key Clinical MessageAcute spinal cord compression in the immediate postoperative period from a possible choriocarcinoma syndrome (CCS) on hemorrhagic epidural spinal metastasis has never been described before and needs to be promptly recognized and managed. A low hemoglobin associated with choriocarcinoma should raise suspicion of this syndrome.
Production of α‐Ketoisocaproate and α‐Keto‐β‐Methylvalerate by Engineered L‐Amino Acid Deaminase
Authors: Yuan Yuxiang , Song Wei , Liu Jia , Chen Xiulai , Luo Qiuling , Liu Liming 
Published: April 2019

AbstractThis study aimed to develop an efficient enzymatic strategy for industrial production of α‐ketoisocaproate (α‐KIC) and α‐keto‐β‐methylvalerate (α‐KMV) from L‐leucine and L‐isoleucine, respectively. L‐amino acid deaminase from Proteus mirabilis (PmLAAD) was heterologously expressed in E. coli BL21(DE3) and modified to increase its catalytic efficiency by engineering the PmLAAD substrate‐binding cavity and entrance tunnel. Four essential residues (Q92, M440, T436, and W438) were identified from structural analysis and molecular dynamics simulations. Residue Q92 was mutated to alanine, and the volume of the binding cavity, enzyme activity, and the kcat/Km value of mutant PmLAAD Q92A increased to 994.2 Å3, 191.36 U mg−1, and 1.23 mM−1 min−1, respectively; consequently, the titer and conversion rate of α‐KIC from L‐leucine were 107.1 g L−1 and 98.1 %, respectively. For mutant PmLAADT436/W438A, the entrance tunnel, enzyme activity, and the kcat/Km value increased to 1.71 Å, 170.12 U mg−1, and 0.70 mM−1 min−1, respectively; consequently, the titer and conversion rate of α‐KMV from L‐isoleucine were 98.9 g L−1 and 99.7 %, respectively. Therefore, augmentation of the substrate‐binding cavity and entrance tunnel of PmLAAD can facilitate efficient industrial synthesis of α‐KIC and α‐KMV.
Cobalt‐Catalyzed Aqueous Dehydrogenation of Formic Acid
Authors: Zhou Wei , Wei Zhihong , Spannenberg Anke , Jiao Haijun , Junge Kathrin , Junge Henrik , Beller Matthias 
Published: April 2019

AbstractAmong the known liquid organic hydrogen carriers, formic acid attracts increasing interest in the context of safe and reversible storage of hydrogen. Here, the first molecularly defined cobalt pincer complex is disclosed for the dehydrogenation of formic acid in aqueous medium under mild conditions. Crucial for catalytic activity is the use of the specific complex 3. Compared to related ruthenium and manganese complexes 7 and 8, this optimal cobalt complex showed improved performance. DFT computations support an innocent non‐classical bifunctional outer‐sphere mechanism on the triplet state potential energy surface.
Flexidentate Coordination Behavior and Chemical Non‐Innocence of a Bis(1,3‐Diphosphacyclobutadiene) Sandwich Anion
Authors: Rödl Christian , Wolf Robert 
Published: April 2019

AbstractThe homoleptic 1,3‐diphosphacyclobutadiene sandwich complex [Co(η4‐1,3‐P2C2tBu2)2]− behaved as a versatile and highly flexible metalloligand toward Ni2+, Ru2+, Rh+, and Pd2+ cations, forming a range of unusual oligonuclear compounds. The reaction of [K(thf)2{Co(η4‐1,3‐P2C2tBu2)2}] with [Ni2Cp3]BF4 initially afforded the σ‐complex [CpNi{Co(η4‐1,3‐P2C2tBu2)2}(thf)] (2), which converted into [Co(η4‐CpNi{1,3‐P2C2tBu2‐κP,κC})(η4‐1,3‐P2C2tBu2)] (3) below room temperature. The structure of 3 contains an unprecedented 1,4‐diphospha‐2‐nickelacyclopentadiene moiety formed by an oxidative addition of a ligand P−C bond onto nickel. At elevated temperatures, 3 isomerized to [Co(η4‐CpNi{1,4‐P2C2tBu2‐κ2P,P})(η4‐1,3‐P2C2tBu2)] (4), which features a 1,3‐diphospha‐2‐nickelacyclopentadiene unit. Transmetalation of [K(thf)2{Co(η4‐1,3‐P2C2tBu2)2}] with [Cp*RuCl]4 (Cp*=C5Me5) afforded tetranuclear [(Cp*Ru)3(μ‐Cl)2{Co(η4‐1,3‐P2C2tBu2)2}] (5), in which the [Co(η4‐1,3‐P2C2tBu2]− anion acts as a chelate ligand toward Ru2+. The diphosphido complex [(Cp*Ru)2(μ,η2‐P2)(μ,η2‐C2tBu2)] (6) was formed as a byproduct. Pure compound 6 was isolated after prolonged heating of the reaction mixture. The reaction of [K(thf)2{Co(η4‐1,3‐P2C2R2)2}] (R=tBu; adamantyl, Ad) with [RhCl(cod)]2 (cod=1,5‐cyclooctadiene) afforded unprecedented π‐complexes [Rh(cod){Co(η4‐1,3‐P2C2R2)2}] (7: R=tBu; 8: R=Ad), in which one μ:η4:η4‐P2C2R2 ligand bridges two metal atoms. The pentanuclear complex [Pd3(PPh3)2{Co(η4‐1,3‐P2C2tBu2)2}2] (10), featuring a Pd3 chain and a rare 1,4‐diphospha‐2‐butene ligand, was synthesized by reacting [K(thf)2{Co(η4‐1,3‐P2C2tBu2)2}] with cis‐PdCl2(PPh3)2. The redox properties of selected compounds were analyzed by cyclic voltammetry, whereas DFT calculations gave additional insight into the electronic structures. The results of this study revealed several remarkable and previously unrecognized properties of the [Co(P2C2tBu2)2]− anion.
Pharmacomicrobiomics: The Holy Grail to Variability in Drug Response?
Authors: Sharma Anukriti , Buschmann Mary M. , Gilbert Jack A. 
Published: April 2019

The human body, with 3.0 × 1013 cells and more than 3.8 × 1013 microorganisms, has nearly a one‐to‐one ratio of resident microbes to human cells. Initiatives like the Human Microbiome Project, American Gut, and Flemish Gut have identified associations between microbial taxa and human health. The study of interactions between microbiome and pharmaceutical agents, i.e., pharmacomicrobiomics, has revealed an instrumental role of the microbiome in modulating drug response that alters the therapeutic outcomes. In this review, we present our current comprehension of the relationship of the microbiome, host biology, and pharmaceutical agents such as cardiovascular drugs, analgesics, and chemotherapeutic agents to human disease and treatment outcomes. We also discuss the significance of studying diet–gene–drug interactions and further address the key challenges associated with pharmacomicrobiomics. Finally, we examine proposed models employing systems biology for the application of pharmacomicrobiomics and other ‐omics data, and provide approaches to elucidate microbiome–drug interactions to improve future translation to personalized medicine.
Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling
Authors: Rodygin Konstantin S. , Vikenteva Yulia A. , Ananikov Valentine P. 
Published: April 2019

AbstractCalcium carbide, a stable solid compound composed of two atoms of carbon and one of calcium, has proven its effectiveness in chemical synthesis, due to the safety and convenience of handling the C≡C acetylenic units. The areas of CaC2 application are very diverse, and the development of calcium‐mediated approaches resolves several important challenges. This Review aims to discuss the laboratory chemistry of calcium carbide, and to go beyond its frontiers to organic synthesis, life sciences, materials and construction, carbon dioxide capturing, alloy manufacturing, and agriculture. The recyclability of calcium carbide and the availability of large‐scale industrial production facilities, as well as the future possibility of fossil‐resource‐independent manufacturing, position this compound as a key chemical platform for sustainable development. Easy regeneration and reuse of the carbide highlight calcium‐based sustainable chemical technologies as promising instruments for total carbon recycling.
Low‐Cost Porous Ruthenium Layer Deposited on Nickel Foam as a Highly Active Universal‐pH Electrocatalyst for the Hydrogen Evolution Reaction
Authors: Xia Jiawei , Volokh Michael , Peng Guiming , Fu Yongsheng , Wang Xin , Shalom Menny 
Published: April 2019

AbstractLow‐cost and high‐efficiency electrocatalysts for the hydrogen evolution reaction (HER) are a key constituent of a low‐carbon industrial economy based on intermittent energy production in the near future. A facile wet‐chemistry strategy has been developed for the synthesis of a porous Ru layer deposited onto Ni foam (NF) as a competitive candidate for HER over the whole pH range, especially under economical alkaline conditions. The catalyst shows outstanding HER performance, which stems from the porosity of the Ru layer, the electronic structure of the electrode, and the charge transfer between the NF and the Ru layer, which gives rise to the strong activity of the Ru layer in the HER process. Moreover, the Ru loading was as low as approximately 1.1 wt %, representing significant potential for application in cost‐effective HER.