bluuebunny/crossref_metadata_2025_split huggingface dataset:
Titanocene‐Catalyzed Radical Opening of N‐Acylated Aziridines
Authors: Zhang Yong‐Qiang , Vogelsang Elisabeth , Qu Zheng‐Wang , Grimme Stefan , Gansäuer Andreas 
Published: August 2017

AbstractAziridines activated by N‐acylation are opened to the higher substituted radical through electron transfer from titanocene(III) complexes in a novel catalytic reaction. This reaction is applicable in conjugate additions, reductions, and cyclizations and suited for the construction of quaternary carbon centers. The concerted mechanism of the ring opening is indicated by DFT calculations.
Diagnosis of disturbance in distillation process based on inversion method
Authors: Tian Wende , Liang Huiting , Zhang Guixin 
Published: August 2017

AbstractMany difficulties are encountered when analyzing hard‐to‐identify underlying causes of disturbances in distillation processes. Direct model‐based fault diagnosis methods often prove to be time‐consuming because they iteratively solve the direct model to obtain representative disturbance parameters. In this paper, an inversion method is proposed for identifying fault causes in the field of distillation diagnosis by mapping measured data against disturbance types. The proposed method consists of an offline phase and an online phase. In the offline phase, both normal and abnormal samples are simulated based on a simplified dynamic mechanistic model, and they are used to establish an inversion model for each disturbance with regard to each characteristic representation quantity using a genetic algorithm (GA). In the online phase, neural network, negative selection algorithm (NSA), and support vector machine (SVM) algorithms are used to determine the disturbance type, and the disturbance quantity is obtained by solving the corresponding inversion model. The proposed method is applied to high purity binary distillation column and benzene–toluene distillation column test cases. Case studies demonstrate that the inversion model‐based diagnosis method can effectively identify disturbances and thus provide theoretical support for the application of quantitative fault diagnosis technology in the chemical industry. © 2017 Curtin University and John Wiley & Sons, Ltd.
Electrospun waterproof breathable membrane with a high level of aerosol filtration
Authors: Maksoud Fouad Junior , Lameh Mohammad , Fayyad Sary , Ismail Nagham , Tehrani‐Bagha Ali Reza , Ghaddar Nesreen , Ghali Kamel 
Published: August 2017

ABSTRACTIn this study, several nanofibrous polyurethane (PU) webs were electrospun (ES) by changing different effective parameters (e.g., polymeric concentration, voltage, feed flow, etc.). The physical–chemical properties of the webs (i.e., average fiber diameters, thickness, areal density, porosity, contact angle, waterproofness, air permeability (AP), water vapor transmittance, and aerosol filtration) were studied based on the standard test methods. A commercially available waterproof breathable (WPB) fabric was used as a reference for benchmarking. The beads‐free webs with an average fiber diameter as small as 200 nm were achieved from electrospinning of 10 wt % PU inN,N‐dimethylformamide, at feed rate of 0.5 mL/h, applied voltage of 25 kV, and tip‐to‐collector distance of 15 cm. By optimizing the electrospinning parameters, a web with a high level of waterproofness, high AP, and high water vapor transmission rate (WVTR) was obtained. In addition, the selected ES membrane showed very promising aerosol filtration efficiency with complete removal of particles larger than 0.5 µm, and 94% reduction in the concentration of smaller particles. We found a linear empirical equation for the estimation of AP and WVTR based on the average pore size diameter, the membrane thickness, and the porosity with very high regression coefficients (R2 > 0.97). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 45660.
Mechanical, thermal, and water absorption properties of melamine–formaldehyde‐treated sisal fiber containing poly(lactic acid) composites
Authors: Tengsuthiwat Jiratti , Asawapirom Udom , Siengchin Suchart , Karger‐Kocsis József 
Published: August 2017

ABSTRACTThe present study focuses on the melamine–formaldehyde (MF) coating ratio and silanization of PLA/sisal composites. Poly(lactic acid) (PLA) was melt blended with short sisal fiber with and without MF resin coating. MF was applied at different weight ratios (sisal:MF = 1:1; 1:3, and 1:5) to coat the untreated or silanized sisal fibers which were incorporated up to 20 parts per hundred resin (phr) amount in PLA. PLA/sisal composites were produced by compression molding. It was found that the sisal:MF coating ratio at 1:1 by weight improved the tensile strength and tensile modulus of the composite with 10 phr sisal by 4% and 57%, respectively, compared to the virgin PLA. The initial and final decomposition (Ti) and (Tf) of PLA with untreated sisal were changed from 330.8 and 367.1 to 336.2 and 370.4 °C, respectively, after MF‐coating (sisal:MF weight ratio = 1:1). This enhancement in thermal stability was attributed to the strong interaction between the MF and sisal fiber. The water absorption of PLA/MF–sisal composites slightly decreased with increasing sisal:MF ratio. This is due to the fact that the MF‐coating substantially reduced the hydrophilic properties of sisal. Moreover, FTIR spectra and SEM images proved that sisal fibers were coated by MF resin successfully. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45681.
A dual‐induced self‐expandable stent based on biodegradable shape memory polyurethane nanocomposites (PCLAU/Fe3O4) triggered around body temperature
Authors: Gu Shu‐Ying , Chang Kun , Jin Sheng‐Peng 
Published: August 2017

ABSTRACTConcerning the occurrence of in‐stent restenosis and stent thrombosis of stent implantation with balloon angioplasty, a dual‐induced self‐expandable stent based on biodegradable shape memory polyurethane nanocomposites (PCLAU/Fe3O4) was developed. The stent could maintain its temporary shape at body temperature for a certain period of time while it was able to recover to its permanent shape at the temperature a little above body temperature (around 40 °C) in both a water bath and an alternating magnetic field. The trigger temperature and remote local heating ensured enough operation time and harmless activation without heating the body tissue. The nanocomposites had high fixing ratios above 99% and recovery ratios above 82% at both 37 and 40 °C. Cytotoxicity and in vitro degradation showed the nanocomposites had good biocompatibility and biodegradability. The PCLAU/Fe3O4 nanocomposites with dual‐responsive shape memory effects, desirable mechanical properties, biocompatibility, and biodegradability show great potential for vascular stents. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45686.
Fabrication of Mesoporous Cu Films on Cu Foils and Their Applications to Dopamine Sensing
Authors: Baba Daisuke , Li Cuiling , Malgras Victor , Jiang Bo , Alamri Hatem R. , Alothman Zeid A. , Hossain Md. Shahriar A. , Yamauchi Yusuke , Asahi Toru 
Published: August 2017

AbstractWe previously succeeded to prepare stable mesoporous Cu films on Au‐coated conductive working electrodes by using polystyrene‐b‐poly(oxyethylene) (PS63 000‐b‐PEO26 000) micelles as template and sulfuric acid to increase ionic conductivity. In the present study, we report the preparation of mesoporous Cu films on Cu foil. By changing the Cu salts and electrodeposition potentials, we discuss how these parameters influence the final product. Without having to filtrate interefering species, such as uric acid, ascorbic acid and glucose, the dopamine concentration can be precisely determined by applying a suitable potential. Therefore, non‐invasive electrochemical sensing based on mesoporous films will be useful for daily diagnosis of mental disorder.
Microbial production of mannitol by Lactobacillus brevis 3‐A5 from concentrated extract of Jerusalem artichoke tubers
Authors: Cao Hailong , Yue Min , Liu Gang , Du Yuguang , Yin Heng 
Published: August 2017

AbstractIn the present study, the conversion of the extract of Jerusalem artichoke tubers for mannitol production by Lactobacillus brevis 3‐A5 was investigated. When the bacterium utilized enzymatic hydrolysates of Jerusalem artichoke extract as the main substrates in batch fermentation, the significant decrease in mannitol productivity was observed when the initial concentration of reducing sugar increased. Then, a strategy of continuous fed‐batch fermentation was adopted for improving mannitol production with enzymatic hydrolysates of Jerusalem artichoke extract as main substrates. Although the concentration of mannitol could reach 199.86 g/L at the end of the fermentation, the productivity for the overall process of the fermentation was only 1.67 g/L/H. To improve the mannitol productivity with both higher yield and concentration, the simultaneous enzymatic saccharification and fermentation (SSF) was studied. In SSF, the mannitol production reached 176.50 g/L in 28 H with a productivity of 6.30 g/L/H and a yield of 0.68 g/g total sugar. Our study provides a cost‐effective and eco‐friendly method for mannitol production from a cheap biomass.
Application of HPLC‐LTQ Orbitrap MS for metabolic profiles of Polygonum multiflora extract in rats
Authors: Zhang Jing , Wang Tenghua , Ren Zhiyao , Gong Lu , Huang Juan , Bai Junqi , Qiu Xiaohui , Xu Wen 
Published: August 2017

AbstractThe root of Polygonum multiflorum (PM) is an important Chinese herbal medicine for treatment of various diseases. Extensive pharmacological studies have been conducted and demonstrated that it shows a wide range of bioactivities. Meanwhile, a considerable number of hepatotoxicity cases owing to oral administration of PM have been reported and have attracted great attention. However, the limited knowledge regarding the metabolism of PM restricts the deeper studies on its pharmacological/toxicological mechanism and therapeutic material basis. The present study aimed to develop a high‐performance liquid chromatography coupled with a linear ion trap–Orbitrap hybrid mass spectrometry method for separation and identification of metabolites in rat urine and plasma after oral administration of PM. Based on the proposed strategy, metabolism profiles of PM in rats were proposed for the first time and 43 metabolites were characterized or tentatively identified. Phase II metabolism, such as glucuronidation and sulfation, are the principal pathways of the main components. These findings will be beneficial to further understanding of the pharmacological mechanism and pharmacodynamic material basis of PM.
Photometric Characterization of the Reductive Amination Scope of the Imine Reductases from Streptomyces tsukubaensis and Streptomyces ipomoeae
Authors: Matzel Philipp , Krautschick Lukas , Höhne Matthias 
Published: August 2017

AbstractImine reductases (IREDs) have emerged as promising enzymes for the asymmetric synthesis of secondary and tertiary amines starting from carbonyl substrates. Screening the substrate specificity of the reductive amination reaction is usually performed by time‐consuming GC analytics. We found two highly active IREDs in our enzyme collection, IR‐20 from Streptomyces tsukubaensis and IR‐Sip from Streptomyces ipomoeae, that allowed a comprehensive substrate screening with a photometric NADPH assay. We screened 39 carbonyl substrates combined with 17 amines as nucleophiles. Activity data from 663 combinations provided a clear picture about substrate specificity and capabilities in the reductive amination of these enzymes. Besides aliphatic aldehydes, the IREDs accepted various cyclic (C4–C8) and acyclic ketones, preferentially with methylamine. IR‐Sip also accepted a range of primary and secondary amines as nucleophiles. In biocatalytic reactions, IR‐Sip converted (R)‐3‐methylcyclohexanone with dimethylamine or pyrrolidine with high diastereoselectivity (>94–96 % de). The nucleophile acceptor spectrum depended on the carbonyl substrate employed. The conversion of well‐accepted substrates could also be detected if crude lysates were employed as the enzyme source.
Structures of the N‐Terminal Domain of PqsA in Complex with Anthraniloyl‐ and 6‐Fluoroanthraniloyl‐AMP: Substrate Activation in Pseudomonas Quinolone Signal (PQS) Biosynthesis
Authors: Witzgall Florian , Ewert Wiebke , Blankenfeldt Wulf 
Published: August 2017

AbstractPseudomonas aeruginosa, a prevalent pathogen in nosocomial infections and a major burden in cystic fibrosis, uses three interconnected quorum‐sensing systems to coordinate virulence processes. At variance with other Gram‐negative bacteria, one of these systems relies on 2‐alkyl‐4(1H)‐quinolones (Pseudomonas quinolone signal, PQS) and might hence be an attractive target for new anti‐infective agents. Here we report crystal structures of the N‐terminal domain of anthranilate‐CoA ligase PqsA, the first enzyme of PQS biosynthesis, in complex with anthraniloyl‐AMP and with 6‐fluoroanthraniloyl‐AMP (6FABA‐AMP) at 1.4 and 1.7 Å resolution. We find that PqsA belongs to an unrecognized subfamily of anthranilate‐CoA ligases that recognize the amino group of anthranilate through a water‐mediated hydrogen bond. The complex with 6FABA‐AMP explains why 6FABA, an inhibitor of PQS biosynthesis, is a good substrate of PqsA. Together, our data might pave a way to new pathoblockers in P. aeruginosa infections.
Lactoferrin induces tropoelastin expression by activating the lipoprotein receptor‐related protein 1‐mediated phosphatidylinositol 3‐kinase/Akt pathway in human dermal fibroblasts
Authors: Ryu Mizuyuki , Nogami Asuka , Kitakaze Tomoya , Harada Naoki , Suzuki Yasushi A. , Yamaji Ryoichi 
Published: August 2017

AbstractDermal fibroblasts generate the extracellular matrix component elastin, which is synthesized as tropoelastin (TE) and play a critical role in maintaining skin elasticity. Lactoferrin (Lf), an 80‐kDa iron‐binding glycoprotein, has biological functions such as anti‐bacterial, ‐inflammatory, and ‐cancer activities. We previously reported that bovine Lf increases TE mRNA expression in human dermal fibroblasts. However, it remains unclear how Lf up‐regulates TE expression. Here, we investigated molecular mechanisms underlying this effect. Lf promoted the phosphorylation of Akt1 and extracellular signal‐regulated protein kinase (ERK)1/2. As expected, the phosphatidylinositol 3‐kinase (PI3K) inhibitor LY294002 and the MAPK inhibitor U0126 inhibited Lf‐induced phosphorylation of Akt1 and ERK1/2, respectively. In contrast, LY294002, but not U0126, inhibited Lf‐induced TE expression. Human dermal fibroblasts expressed lipoprotein receptor‐related protein 1 (LRP‐1) mRNA, and the LRP1 inhibitor receptor‐associated protein attenuated Lf‐induced increases in TE expression. Furthermore, siRNA‐mediated knockdown of LRP‐1 significantly suppressed Lf‐increased TE expression and Lf‐induced Akt1 phosphorylation. Iron‐saturated Lf (holo‐Lf) increased TE expression and promoted Akt1 phosphorylation, when compared to those parameters in cells treated with iron‐free Lf (apo‐Lf). Transforming growth factor (TGF)‐β1 also increased TE expression. LY294002 inhibited TGF‐β1‐mediated TE upregulation, whereas TGF‐β1 activated Akt2, but not Akt1, phosphorylation. These results indicate that holo‐Lf, but not apo‐Lf, increases TE expression through LRP‐1 in human dermal fibroblasts and suggest that holo‐Lf and TGF‐β1 enhance TE expression by activating the PI3K/Akt1 and PI3K/Akt2 pathways, respectively.
Diversity‐Oriented Syntheses by Combining CuAAC and Stereoselective INCIC Reactions with Peptides
Authors: Wang Yuanyuan , Madsen Anders Ø. , Diness Frederik , Meldal Morten 
Published: August 2017

AbstractCascade reactions proceeding through peptide‐derived N‐carbamoyl iminium ions are reported. Two new reactions of N‐carbamoyl iminium ions are described, including a stereoselective double cyclization generating N,N′‐aminals and an acid‐promoted auto‐oxidation. Mechanistic investigations revealed that the N,N′‐aminal formation is reversible under strongly acidic conditions. Both of these new reactions proved to be completely orthogonal to subsequent CuAAC chemistry. The reactions were performed in solution and on solid support. The robustness and high stereoselectivity of the methodology holds great promise for applications in parallel diversity‐oriented synthesis and in combinatorial synthesis for drug screening.
Transition‐Metal‐Controlled Inorganic Ligand‐Supported Non‐Precious Metal Catalysts for the Aerobic Oxidation of Amines to Imines
Authors: Yu Han , Zhai Yongyan , Dai Guoyong , Ru Shi , Han Sheng , Wei Yongge 
Published: August 2017

AbstractMost state‐of‐art transition‐metal catalysts usually require organic ligands, which are essential for controlling the reactivity and selectivity of reactions catalyzed by transition metals. However, organic ligands often suffer from severe problems including cost, toxicity, air/moisture sensitivity, and being commercially unavailable. Herein, we show a simple, mild, and efficient aerobic oxidation procedure of amines using inorganic ligand‐supported non‐precious metal catalysts 1, (NH4)n[MMo6O18(OH)6] (M=Cu2+; Fe3+; Co3+; Ni2+; Zn2+, n=3 or 4), synthesized by a simple one‐step method in water at 100 °C, demonstrating that the catalytic activity and selectivity can be significantly improved by changing the central metal atom. In the presence of these catalysts, the catalytic oxidation of primary and secondary amines, as well as the coupling of alcohols and amines, can smoothly proceed to afford various imines with O2 (1 atm) as the sole oxidant. In particular, the catalysts 1 have transition‐metal ion core, and the planar arrangement of the six MoVI centers at their highest oxidation states around the central heterometal can greatly enhance the Lewis acidity of catalytically active sites, and also enable the electrons in the center to delocalize onto the six edge‐sharing MO6 units, in the same way as ligands in traditional organometallic complexes. The versatility of this methodology maybe opens a path to catalytic oxidation through inorganic ligand‐coordinated metal catalysis.
Arsenic‐Mediated C−C Coupling of Cyanides Leading to Cyanido Arsazolide [AsC4N4]−
Authors: Arlt Sören , Harloff Jörg , Schulz Axel , Stoffers Alrik , Villinger Alexander 
Published: August 2017

AbstractThe chemistry of arsenic cyanides has been investigated and is found to be completely different to the chemistry of the heavier analogs antimony and bismuth as well as phosphorus. The reaction of As(CN)3 with cyanide salts resulted in the formation of an unknown cyanido arsazolide heterocycle, which represents a structure isomer of the desired [As(CN)4]−. The structure, bonding, and formation of this unusual heterocycle is discussed featuring an arsenic mediated C−C coupling of cyanides. [AsC4N4]− salts with different counterions such as [PPh4]+, [PPN]+=[Ph3P‐N‐PPh3]+, Ag+, and [BMIm]+ are reported with [BMIm][AsC4N4] being a low‐temperature ionic liquid (Tm=−62 °C).
Degradation of bisphenol A by the UV and UV/H2O2 processes: Evaluation of process variables through experimental design
Authors: Goulart de Araujo Leandro , Santos Flaviane da Silva , Teixeira Antonio Carlos Silva Costa 
Published: August 2017

AbstractUV‐based technologies have been proposed for the treatment of wastewater containing bisphenol A (BPA), a toxic, endocrine‐disruptor pollutant. Nevertheless, the evaluation of the role of process variables through experimental design has not been previously addressed. In this study, the effects of BPA and H2O2 initial concentrations, and specific photon emission rate (EP,0) on BPA degradation by the UV and UV/H2O2 processes were investigated, using the Doehlert design and response surface analysis. The experiments were performed in a tubular reactor equipped with a 254‐nm UV lamp, for [H2O2]0 and EP,0 in the ranges 1.6–9.6 mmol · L−1 and 0.87 × 1018–3.6 × 1018 photons · L−1 · s−1, respectively. Photolysis ([BPA]0 = 10–50 mg · L−1) was shown to be inefficient for BPA degradation and mineralization, with pollutant removals lower than 55 %. The specific BPA photolysis rate and BPA removal decreased with increasing [BPA]0. In contrast, all the UV/H2O2 experiments ([BPA]0 = 50 mg · L−1) resulted in total BPA degradation after 60 min of irradiation. In this case, the best conditions were [H2O2]0 = 7.6 mmol · L−1 and Ep,0 = 3.6 × 1018 photons · L−1 · s−1, achieving the highest BPA degradation rate and removal after 15 min, and the second highest TOC removal after 180 min. In most experiments less than 75 % TOC removal was achieved, with 95 % mineralization observed solely for the highest [H2O2]0 and EP,0. In any case, the residual toxicity and endocrine activity of treated solutions must be determined, in order to prove the applicability of the UV/H2O2 process for real water and wastewater treatment.
Hydrodynamic design of multi‐zone circulating reactors using CFD
Authors: Marandi Reza , Kamyabi Mohammadmahdi , Mostoufi Navid 
Published: August 2017

AbstractA 3D model was developed for simulating the hydrodynamics of polypropylene powders in multi‐zone circulating reactors (MZCRs). This model was used to design the proper geometry of the reactor. The model was based on computational fluid dynamics (CFD) in which an Eulerian‐Eulerian approach, incorporating the kinetic theory of granular flow (KTGF), was used to describe gas and solid flow equations. The re‐normalization group (RNG) k‐ϵ model was applied for implementing the turbulency. For finding the best design of the reactor from the hydrodynamic point of view, four geometrical configurations were proposed and tested. It was found that the best configuration has a narrower downer (compared to riser), and a return leg with a side flow which results in a good solid circulation and proper solid distribution in the reactor. This configuration ensures fast fluidization and pseudo packed bed regimes within the riser and downer, respectively. Effect of inlet gas velocity on overriding parameters, such as pressure drop and solid volume fraction, was studied for the selected configuration. Upper and lower limits for the inlet gas velocity were determined.
Association between modifiable lifestyle and the prevalence of atrial fibrillation in a Chinese population: Based on the cardiovascular health score
Authors: Yang Yiheng , Han Xu , Chen Yue , Gao Lianjun , Yin Xiaomeng , Li Huihua , Qiu Jing , Wang Youxin , Zhou Yong , Xia Yunlong 
Published: August 2017

BackgroundThe Cardiovascular Health (CVH) Score was comprised of a series of modifiable lifestyle and health factors, which was published by American Heart Association in 2010. Its relationship with atrial fibrillation (AF) remains unclear.HypothesisIndividuals with a higher CVH Score had a lower risk of AF.MethodsParticipants ≥40 years of age were recruited from the Jidong community. Information regarding the following 7 CVH metrics, including smoking, body mass index, diet, physical activity, total cholesterol, and fasting blood glucose, were collected. AF was confirmed with a standard 12‐lead electrocardiography or based on the patients' medical histories. A multivariable logistic regression model was used to evaluate the relationship between ideal CVH and AF prevalence.ResultsThis study included 4477 individuals, among whom 48 had AF (1.07%). Overall, participants with higher ideal components scores had a lower risk of AF (odds ratio [OR]: 0.78; 95% confidence intervals [CI]: 0.62‐0.97; P trend = 0.024). Subgroup analyses showed that the trend was consistent in the male participants ages 40 to 60 years. Moreover, patients with 5 to 7 ideal components or 3 to 4 ideal components were associated with 57% and 59% reduced risks for AF, respectively. We also detected a significant association between ideal health factors and the prevalence of AF (OR: 0.79; 95% CI: 0.68‐0.93; P = 0.004).ConclusionsIdeal health behavior and factors are associated with lower prevalence of AF in a community‐based population. Improving healthy behavior and these factors may be beneficial to decrease the prevalence of AF.