bluuebunny/crossref_metadata_2025_split huggingface dataset:
Enantio‐ and Diastereoselective Suzuki–Miyaura Coupling with Racemic Bicycles
Authors: Goetzke F. Wieland , Mortimore Mike , Fletcher Stephen P. 
Published: June 2019

AbstractHerein, we describe a rhodium‐catalyzed enantio‐ and diastereoselective Suzuki–Miyaura cross‐coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl, heteroaryl, and alkenyl boronic acids and gives access to functionalized bicyclic cyclopentenes, which can be converted into other five‐membered‐ring scaffolds with up to five contiguous stereocenters. Preliminary mechanistic studies suggest that these reactions occur with overall retention of the relative stereochemistry and are enantioconvergent for pseudo‐symmetric allylic chloride starting materials. In addition, a bicyclic allylic chloride starting material without pseudo‐symmetry undergoes a highly enantioselective regiodivergent reaction.
Contamination and Disinfection of Rigid Laryngoscopes: A Literature Review
Authors: Van Wicklin Sharon Ann 
Published: June 2019

ABSTRACTThis article reviews current literature about the contamination of laryngoscope blades and handles, disinfection practices for laryngoscope blades and handles, and environmental effects and costs of reusable and single‐use laryngoscopes. This review shows that inadequately processed rigid laryngoscopes may have the ability to transmit infections to patients and health care personnel. Although the laryngoscope handle has been considered a noncritical item that contacts only intact skin, health care team members should consider both the laryngoscope blade and handle as semicritical items and process them by high‐level disinfection (HLD) or steam sterilization according to manufacturer's instructions. The fewest environmental effects occur when a reusable stainless‐steel laryngoscope is processed by HLD. Laryngoscope costs are lower for processing reusable laryngoscope handles and blades by HLD and highest for single‐use laryngoscopes. Evidence‐based guidelines are needed to specify and standardize best practices for processing rigid laryngoscopes.
Polymer brushes on graphene oxide for efficient adsorption of heavy metal ions from water
Authors: Liu Dejian , Ding Congcong , Chi Fangting , Pan Ning , Wen Jun , Xiong Jie , Hu Sheng 
Published: June 2019

ABSTRACTThe pollution of heavy metal ions in water poses a serious threat to human being and ecosystems. Here, we report polyamidoxime (PAO) brush grafted graphene oxide (GO) as a highly efficient adsorbent for extraction of toxic metal cations from water. Surface‐initiated atom transfer radical polymerization was used to grow polyacrylonitrile (PAN) brushes on GO, followed by conversion of the nitrile groups in PAN into amidoxime groups, which had high binding affinity toward heavy metal cations. The PAO brush grafted GO demonstrated significantly fast adsorption kinetics and large adsorption capacity. At optimal pH 5, the PAO brush grafted GO can achieve maximum adsorption capacities of 116.7 mg g−1 for Pb(II), 258.6 mg g−1 for Ag(I), 192.2 mg g−1 for Cu(II), and 167.9 mg g−1 for Fe(III), which were significantly larger than those of small molecule functionalized GO. Mechanism analysis suggested that the enhanced adsorption performance was due to the myriads of functional groups in PAO brushes that were easily accessible to metal ions because of the swelling of the polymer brushes in water. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48156.
Influence of aorta extracellular matrix in electrospun polycaprolactone scaffolds
Authors: Reid James A. , Callanan Anthony 
Published: June 2019

ABSTRACTCardiovascular disease is the leading cause of mortality worldwide. Therefore, new research strategies for the treatment of cardiovascular disease are required. Previously, extracellular matrices (ECMs) have been used alongside polymers to generate hybrid bioscaffolds. Herein, we propose combining aortic ECMs with a polycaprolactone electrospun scaffold and biomechanically evaluating the scaffolds. We electrospun three scaffolds with varying ECM concentrations and found that increasing the ECM concentration leads to decreased stiffness at low strains, increased elasticity at high strain, reduction in failure strain, and an increase in yield strength. We also noted a decrease in water droplet contact angle with the increasing ECM concentration. Furthermore, we found that all three scaffolds were capable of maintaining human umbilical vein endothelial cell attachment and survival. These findings show the wide spectrum of mechanical properties that can be achieved through the addition of different concentrations of ECM into the fibers. © 2019 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48181.
Effect of β‐nucleating agent and zeolite molecular sieves on supercritical CO2‐assisted cell and crystal nucleation during the long‐chain‐branched polypropylene foaming
Authors: Jiang Hanchuan , Yu Kesong , Mi Jianguo , Zhou Hongfu , Chen Shihong , Wang Xiangdong 
Published: June 2019

ABSTRACTIt is of great interest and importance to design and fabricate the double crystal melting peak (DCMP) structure for the expanded polypropylene (EPP) bead foams during sintering. Two kinds of methods with different mechanisms were proposed to prepare long‐chain‐branched polypropylene (LCBPP) samples with a DCMP structure: One was that the DCMP structure was prepared by generating crystals of different perfection degrees and the other one was that the DCMP structure was prepared by adding β‐NA to produce various crystal forms. In addition, zeolite molecular sieve (ZMS) as the synergist was introduced into LCBPP/β‐NA system to increase the efficiency of β‐NA. The crystallization behaviors of various PP and their foams were tested by differential scanning calorimetry and wide‐angle X‐ray diffraction, as well as the cellular morphologies of various LCBPP foams were observed by scanning electron microscope. The results showed that a DCMP structure was formed in pure LCBPP in the presence of CO2 at 168–172 °C. The content of β‐crystal in LCBPP/β‐NA system was the highest when the content of β‐NA optimized as 1.5 phr. The percentage of β‐crystal in LCBPP/β‐NA system was further increased when a small content (0.045 phr) of ZMS was added. Compared with that in unfoamed LCBPP, the percentage of β‐crystal in LCBPP foams was obviously enhanced, due to the coupling effect of crystal nucleation and cell nucleation. In the LCBPP foams, the cell size became smaller and the cell density became larger, owing to the addition of ZMS. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48183.
Mesoporous Rh Emerging from Nanophase‐separated Rh‐Y Alloy
Authors: Najib Abdillah Sani Bin Mohd , Peng Xiaobo , Hashimoto Ayako , Shoji Shusaku , Iida Takayuki , Bai Yunxing , Abe Hideki 
Published: June 2019

AbstractMesoporous precious metals with abundant active sites and high surface area have been widely recognized as high‐performance catalytic materials. However, the templated synthesis is complex and costly. Herein, we report a mesoporous rhodium (m‐Rh) that can be readily synthesized from entangled nanofibres of Rh and Y2O3 without templates. The entangled nanofibres, prepared from uniform Rh‐Y alloys under redox atmosphere, were the key precursor in the synthesis processes. Moreover, the m‐Rh efficiently catalyzed carbon dioxide reforming of methane (DRM) at a low reaction temperature of 683 K. Further, electrochemical methods of CO electro‐oxidation were innovatively used to demonstrate the stability of CO and oxygen species for the DRM reaction.
PBA@POM Hybrids as Efficient Electrocatalysts for the Oxygen Evolution Reaction
Authors: Wang Yuyin , Wang Yan , Zhang Li , Liu Chun‐Sen , Pang Huan 
Published: June 2019

AbstractTo realize the effective conversion of renewable energy through water decomposition, efficient electrocatalysts for the oxygen evolution reaction (OER) are essential. In this article, PBA@POM was successfully prepared with a Prussian blue analogue (PBA) as the initial structure. A facile hydrothermal process is reported for obtaining PBA@POM by etching the cubic PBA with a strong Brønsted acid, H3PMo12O40 (HPMo). The hollow cube structure not only exposes more active sites but also promotes electron transport, which results in excellent electrocatalytic activity for the OER. Compared with the PBA, which initially simply adhered to POM, the optimum PBA@POM hybrids display remarkably enhanced OER catalytic activity, with an almost constant overpotential of 440 mV at a current density of 10 mA cm−2 and a small Tafel slope (23.45 mV dec−1). The facilely prepared PBA@POM with good electrochemical activity and stability promises great potential for the OER.
Stability and stabilization of evolutionary games with time delays via matrix method
Authors: Gao Xiaoye , Wang Jinhuan , Yang Dedong 
Published: June 2019

AbstractThis paper studies the stability and stabilization of a class of evolutionary games (EGs) with time delays via the semi‐tensor product (STP) method. First, the matrix expression of the EGs with time delays is given, and then it is converted into the form without delay equivalently. By designing Lyapunov function, a necessary and sufficient condition for the global stability of delayed EGs is obtained. To deal with the delayed EGs with multiple equilibriums, the controlled EGs with time delays is investigated. An intermittent state feedback control is proposed, in which the controller works only at certain strategy profiles. Based on the intermittent control, two necessary and sufficient conditions are provided to assure the stabilization of the controlled EGs with time delays. Some examples are worked out to illustrate the effectiveness of the theoretical results.
Searching for Sympatric Speciation in the Genomic Era
Authors: Richards Emilie J. , Servedio Maria R. , Martin Christopher H. 
Published: June 2019

Sympatric speciation illustrates how natural and sexual selection may create new species in isolation without geographic barriers. However, recent genomic reanalyses of classic examples of sympatric speciation reveal complex histories of secondary gene flow from outgroups into the radiation. In contrast, the rich theoretical literature on this process distinguishes among a diverse range of models based on simple genetic histories and different types of reproductive isolating barriers. Thus, there is a need to revisit how to connect theoretical models of sympatric speciation and their predictions to empirical case studies in the face of widespread gene flow. Here, theoretical differences among different types of sympatric speciation and speciation‐with‐gene‐flow models are reviewed and summarized, and genomic analyses are proposed for distinguishing which models apply to case studies based on the timing and function of adaptive introgression. Investigating whether secondary gene flow contributed to reproductive isolation is necessary to test whether predictions of theory are ultimately borne out in nature.
Nuclear fast red‐based colorimetric sensors for sensitive and selective detection of Ag ions
Authors: Xiong Yuan , Wang Yi , Han Xue , Ma Yao , Zhu Han Fang , Long YunFei , Chen Shu 
Published: June 2019

AbstractThe reduction of nuclear fast red (NFR) stain by sodium tetrahydroboron was catalyzed in the presence of silver ions (Ag+). The fluorescence properties of reduced NFR differed from that of NFR. The product showed fluorescence emission at 480 nm with excitation at 369 nm. Furthermore, the fluorescence intensity of the mixture increased strongly in the presence of Ag+ and Britton–Robinson buffer at pH 4.78. There was a good linear relationship between increased fluorescence intensity (ΔI) and Ag+ concentration in the range 5.0 × 10−9 to 5.0 × 10−8 M. The correlation coefficient was 0.998, and the detection limit (3σ/k) was 1.5 × 10−9 M. The colour of the reaction system changed with variation in Ag+ concentration over a wide range. Based on the colour change, a visual semiquantitative detection method for recognition and sensing of Ag+ was developed for the range 1.0 × 10−8 to 5.0 × 10−4 M, with an indicator that was visible to the naked eye. Therefore, a sensitive, simple method for determination of Ag+ was developed. Optimum conditions for Ag+ detection, the effect of other ions and the analytical application of Ag+ detection of synthesized sample were investigated.
Reduced m6A modification predicts malignant phenotypes and augmented Wnt/PI3K‐Akt signaling in gastric cancer
Authors: Zhang Cheng , Zhang Mengqi , Ge Sai , Huang Wenwen , Lin Xiaoting , Gao Jing , Gong Jifang , Shen Lin 
Published: June 2019

AbstractBackgroundAs the most abundant epigenetic modification on mRNAs and long non‐coding RNAs, N6‐methyladenosine (m6A) modification extensively exists in mammalian cells. Controlled by writers (methyltransferases), readers (signal transducers), and erasers (demethylases), m6A influences mRNA structure, maturation, and stability, thus negatively regulating protein expression in a post‐translational manner. Nevertheless, current understanding of m6A's roles in tumorigenesis, especially in gastric cancer (GC) remains to be unveiled. In this study, we assessed m6A's clinicopathological relevance to GC and explored the underlying mechanisms.MethodsBy referring to a proteomics‐based GC cohort we previously generated and the TCGA‐GC cohort, we merged expressions of canonical m6A writers (METTL3/METTL14), readers (YTHDF1/YTHDF2/YTHDF3), and erasers (ALKBH5/FTO), respectively, as W, R, and E signatures to represent m6A modification. We stratified patients according to these signatures to decipher m6A's associations with crucial mutations, prognosis, and clinical indexes. m6A's biological functions in GC were predicted by gene set enrichment analysis (GSEA) and validated by in vitro experiments.ResultsWe discovered that W and R were potential tumor suppressive signatures, while E was a potential oncogenic signature in GC. According to W/R/E stratifications, patients with low m6A‐indications were accompanied with higher mutations of specific genes (CDH1, AR, GLI3, SETBP1, RHOA, MUC6, and TP53) and also demonstrated adverse clinical outcomes. GSEA suggested that reduced m6A was correlated with oncogenic signaling and phenotypes. Through in vitro experiments, we proved that m6A suppression (represented by METTL14 knockdown) promoted GC cell proliferation and invasiveness through activating Wnt and PI3K‐Akt signaling, while m6A elevation (represented by FTO knockdown) reversed these phenotypical and molecular changes. m6A may also be involved in interferon signaling and immune responses of GC.ConclusionsOur work demonstrated that low‐m6A signatures predicted adverse clinicopathological features of GC, while the reduction of RNA m6A methylation activated oncogenic Wnt/PI3K‐Akt signaling and promoted malignant phenotypes of GC cells.
Factors Governing the Thermal Stability of Lasso Peptides
Authors: Hegemann Julian D. 
Published: June 2019

AbstractLasso peptides belong to the natural product superfamily of ribosomally synthesized and post‐translationally modified peptides (RiPPs). They are defined by an N‐terminal macrolactam ring that is threaded by the C‐terminal tail. In class II lasso peptides, this fold is maintained only through steric hindrance. Nonetheless, this fold can often withstand prolonged incubation at highly elevated temperatures. However, some lasso peptides will irreversibly unthread into their branched‐cyclic counterparts upon heating. In recent years, an increasing number of research studies have focused on studying the factors that govern the thermal stability (or the lack thereof) of lasso peptides by using in vitro stability assays, mutational analysis, and molecular dynamics simulations. In this review, the current state of understanding the physicochemical parameters deciding the fate of a lasso peptide at elevated temperatures is discussed, and an overview is given of the techniques developed to streamline the separation and discrimination of lasso peptides from their branched‐cyclic topoisomers.
PtPdNi Catalysts Supported on Porous Carbon for Ethanol Electro‐oxidation
Authors: Arroyo‐Gómez José J. , Barrera Deicy , Castagna Rodrigo M. , Sieben Juan Manuel , Alvarez Andrea E. , Duarte Marta M. E , Sapag Karim 
Published: June 2019

AbstractIn this work, we prepared four electrocatalysts based on trimetallic PtPdNi nanoparticles on different carbon supports, i. e., i) two activated carbons produced from biomass, ii) micro‐mesoporous carbon synthesized by the nanocasting method, and iii) commercial carbon black. The electrocatalytic activity of the prepared materials was tested in the electro‐oxidation of ethanol in alkaline medium. Well‐distributed nanoparticles with sizes in the range of 3.5–5.2 nm were obtained through galvanic replacement. The bulk Pt, Pd and Ni contents were about 65, 25 and 15 at. %, measured by EDX and ICP‐AES. By XPS the surface Pt : Pd atomic ratios were in the range of 1.82–2.2. Electrochemical experiments showed that the trimetallic nanoparticles deposited over micro‐mesoporous carbon material exhibit the highest electrochemical activity towards ethanol electro‐oxidation in alkaline medium. Results showed that both synthetic carbon and biomass‐derived carbon are suitable materials to support electrocatalysts in low‐temperature fuel cells.
Hierarchical‐dimensional Material: A Co(OH)2 Superstructure with Hybrid Dimensions for Enhanced Water Oxidation
Authors: Qi Jing , Chen Mingxing , Zhang Wei , Cao Rui 
Published: June 2019

AbstractHerein, we propose the concept of hierarchical‐dimensional materials (HDMs), which are 3D superstructures built by low‐dimensional single‐crystalline substructures. HDMs combine the low‐ and high‐dimensional features and are a new class of promising functional materials toward electrochemical reactions. We reported a hierarchical‐dimensional cobalt hydroxide nanosheet assembly for electrocatalytic water oxidation. The assembling is 1D‐oriented, the substructures are 2D nanosheets, and 3D voids are created in the material. The as‐prepared material achieved superior electrocatalytic activity than isolated substructures. The better performance is associated with the improved mass transport, which is demonstrated by the analysis of kinetic‐controlled currents. This protocol can also be applied in preparing efficient catalysts on the surface of industrial current collectors. The proposed concept of HDMs might open a new area of functional materials in heterogeneous electrocatalysis.
Structure and Energetics of Ligand–Fluorine Interactions with Galectin‐3 Backbone and Side‐Chain Amides: Insight into Solvation Effects and Multipolar Interactions
Authors: Kumar Rohit , Ignjatović Majda Misini , Peterson Kristoffer , Olsson Martin , Leffler Hakon , Ryde Ulf , Nilsson Ulf J. , Logan Derek T. 
Published: June 2019

AbstractMultipolar fluorine–amide interactions with backbone and side‐chain amides have been described as important for protein–ligand interactions and have been used to improve the potency of synthetic inhibitors. In this study, fluorine interactions within a well‐defined binding pocket on galectin‐3 were investigated systematically using phenyltriazolyl‐thiogalactosides fluorinated singly or multiply at various positions on the phenyl ring. X‐ray structures of the C‐terminal domain of galectin‐3 in complex with eight of these ligands revealed potential orthogonal fluorine–amide interactions with backbone amides and one with a side‐chain amide. The two interactions involving main‐chain amides seem to have a strong influence on affinity as determined by fluorescence anisotropy. In contrast, the interaction with the side‐chain amide did not influence affinity. Quantum mechanics calculations were used to analyze the relative contributions of these interactions to the binding energies. No clear correlation could be found between the relative energies of the fluorine–main‐chain amide interactions and the overall binding energy. Instead, dispersion and desolvation effects play a larger role. The results confirm that the contribution of fluorine–amide interactions to protein–ligand interactions cannot simply be predicted, on geometrical considerations alone, but require careful consideration of the energetic components.
Prolidase enzyme is required for extracellular matrix integrity and impacts on postnatal cerebellar cortex development
Authors: Insolia Violetta , Priori Erica C. , Gasperini Caterina , Coppa Federica , Cocchia Marco , Iervasi Erika , Ferrari Beatrice , Besio Roberta , Maruelli Silvia , Bernocchi Graziella , Forlino Antonella , Bottone Maria G. 
Published: June 2019

AbstractThe extracellular matrix is essential for brain development, lamination, and synaptogenesis. In particular, the basement membrane below the pial meninx (pBM) is required for correct cortical development. The last step in the catabolism of the most abundant protein in pBM, collagen Type IV, requires prolidase, an exopeptidase cleaving the imidodipeptides containing pro or hyp at the C‐terminal end. Mutations impairing prolidase activity lead in humans to the rare disease prolidase deficiency characterized by severe skin ulcers and mental impairment. Thus, the dark‐like (dal) mouse, in which the prolidase is knocked‐out, was used to investigate whether the deficiency of prolidase affects the neuronal maturation during development of a brain cortex area. Focusing on the cerebellar cortex, thinner collagen fibers and disorganized pBM were found. Aberrant cortical granule cell proliferation and migration occurred, associated to defects in brain lamination, and in particular in maturation of Purkinje neurons and formation of synaptic contacts. This study deeply elucidates a link between prolidase activity and neuronal maturation shedding new light on the molecular basis of functional aspects in the prolidase deficiency.
Insights into the Aggregation Behaviour of a Benzoselenadiazole‐Based Compound and Generation of White Light Emission
Authors: Maiti Sayan , Jadhav Rohit G. , Mobin Shaikh M. , Mukherjee Tushar K. , Das Apurba K. 
Published: June 2019

AbstractWe have designed and synthesized the benzoselenadiazole (BDS) based donor‐acceptor‐donor (D‐A‐D) π‐conjugated compound 4,7‐di((E)styryl)benzo[2,1,3]selenadiazole (1). A single‐crystal study of 1 shows J‐type molecular aggregation in the solid state. The crystal packing of 1 shows head‐to‐head dimeric intermolecular assembly via Se⋅⋅⋅N interactions while staircase‐type interlock molecular packing has occurred via Se⋅⋅⋅π interaction. The staircase‐type interlock packing of dimeric molecular arrangement induces sheet‐type, herringbone type architecture along crystallographic a axis and ab plane via CH⋅⋅⋅π interactions. Interestingly, the J‐type aggregation of 1 in solid state changes to H‐type aggregation upon UV‐irradiation. Moreover, our spectroscopic findings in solution state reveal H‐type of aggregation of 1 in 90 % aqueous THF. We have further demonstrated white light emission in the binary mixture of 1 and 1‐pyrenemethanol (2) in 90 % aqueous THF. Our study reveals solvent specific co‐assembly of H‐aggregated 1 and 2 in 90 % aqueous THF solution, which shows white light emissive properties with the Commission Internationale de l'Eclairage (CIE) chromaticity coordinates (0.32, 0.31). The observed white light emission arises mainly due to the combination of red light from H‐aggregated 1, blue light from monomeric 2 and green light from excimers of 2.