bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Synthesis of Imidazo‐Fused N‐Heteroaromatic Compounds through a C−N Bond‐Forming Radical Cascade
Authors: Hou Zhong‐Wei , Mao Zhong‐Yi , Melcamu Yared Yohannes , Lu Xin , Xu Hai‐Chao 
Published: December 2017

AbstractWe have developed a unified strategy for preparing a variety of imidazo‐fused N‐heteroaromatic compounds through regiospecific electrochemical (3+2) annulation reaction of heteroarylamines with tethered internal alkynes. The electrosynthesis employs a novel tetraarylhydrazine as the catalyst, has a broad substrate scope, and obviates the need for transition‐metal catalysts and oxidizing reagents.
Brønsted‐Säure‐katalysierte Carbonyl‐Olefin‐Metathese in einer selbstorganisierten supramolekularen Wirtstruktur
Authors: Catti Lorenzo , Tiefenbacher Konrad 
Published: December 2017

AbstractDie Carbonyl‐Olefin‐Metathese ist eine leitsungsfähige, aber unterentwickelte Methode für die Ausbildung von Kohlenstoff‐Kohlenstoff‐Bindungen. Bisher wurde kein Brønsted‐Säure‐basiertes Protokoll für die katalytische Carbonyl‐Olefin‐Metathese in der Literatur beschrieben. Wir präsentieren ein cokatalytisches System, das auf einer einfachen Brønsted‐Säure (HCl) und einer selbstassemblierenden supramolekularen Wirtstruktur basiert. Das entwickelte System schneidet im Vergleich mit dem derzeitigen Benchmark‐Katalysator für die Carbonyl‐Olefin‐Metathese hinsichtlich Substratbreite und Ausbeute gut ab. Die durchgeführten Kontrollversuche liefern sehr gute Hinweise, dass die Reaktion innerhalb der Kavität des supramolekularen Wirts abläuft. Eine mechanistische Studie deutet auf einen schrittweisen Reaktionsmechanismus hin.
Rhodium‐Catalyzed Enantioposition‐Selective Hydroarylation of Divinylphosphine Oxides with Aryl Boroxines
Authors: Wang Zhe , Hayashi Tamio 
Published: December 2017

AbstractThe rhodium‐catalyzed hydroarylation of divinylphosphine oxides (RP(O)(CH=CH2)2) with aryl boroxines ((ArBO)3) gives the corresponding monoarylation products (RP(O)(CH=CHAr)CH2CH3) in high yields. One of the two vinyl groups in the phosphine oxide undergoes oxidative arylation while the other one is reduced to an ethyl moiety. These reactions proceed with high selectivity in terms of the enantiotopic vinyl groups in the presence of (R)‐DTBM‐segphos/Rh to give the P‐stereogenic monoarylation products with high enantioselectivity.
Vacancy‐Controlled Na+ Superion Conduction in Na11Sn2PS12
Authors: Duchardt Marc , Ruschewitz Uwe , Adams Stefan , Dehnen Stefanie , Roling Bernhard 
Published: December 2017

AbstractHighly conductive solid electrolytes are crucial to the development of efficient all‐solid‐state batteries. Meanwhile, the ion conductivities of lithium solid electrolytes match those of liquid electrolytes used in commercial Li+ ion batteries. However, concerns about the future availability and the price of lithium made Na+ ion conductors come into the spotlight in recent years. Here we present the superionic conductor Na11Sn2PS12, which possesses a room temperature Na+ conductivity close to 4 mS cm−1, thus the highest value known to date for sulfide‐based solids. Structure determination based on synchrotron X‐ray powder diffraction data proves the existence of Na+ vacancies. As confirmed by bond valence site energy calculations, the vacancies interconnect ion migration pathways in a 3D manner, hence enabling high Na+ conductivity. The results indicate that sodium electrolytes are about to equal the performance of their lithium counterparts.
Folding DNA into a Lipid‐Conjugated Nanobarrel for Controlled Reconstitution of Membrane Proteins
Authors: Dong Yuanchen , Chen Shuobing , Zhang Shijian , Sodroski Joseph , Yang Zhongqiang , Liu Dongsheng , Mao Youdong 
Published: December 2017

AbstractBuilding upon DNA origami technology, we introduce a method to reconstitute a single membrane protein into a self‐assembled DNA nanobarrel that scaffolds a nanodisc‐like lipid environment. Compared with the membrane‐scaffolding‐protein nanodisc technique, our approach gives rise to defined stoichiometry, controlled sizes, as well as enhanced stability and homogeneity in membrane protein reconstitution. We further demonstrate potential applications of the DNA nanobarrels in the structural analysis of membrane proteins.
Photoinduced Rearrangement of Dienones and Santonin Rerouted by Amines
Authors: Zhang Zhipeng , Ratnikov Maxim , Spraggon Glen , Alper Phil B. 
Published: December 2017

AbstractThe photoinduced rearrangement pathways of simple 2,5‐dienones and the natural product santonin were found to be effectively rerouted by amines, giving rise to unprecedented products. Either cis olefins or cyclobutenes were obtained from 4,4‐disubstituted 2,5‐dienone upon irradiation (365 nm) in the presence of various amines depending on the solvent. Previously undescribed [4.4.0] and [5.3.0] fused‐ring‐containing products were obtained when santonin was irradiated (365 nm) in the presence of methylamine. The amines present in these reactions were incorporated into the products by means of amide‐group formation.
N‐Heterocyclic Carbene Boranes as Reactive Oxygen Species‐Responsive Materials: Application to the Two‐Photon Imaging of Hypochlorous Acid in Living Cells and Tissues
Authors: Pak Yen Leng , Park Sang Jun , Wu Di , Cheon BoHyun , Kim Hwan Myung , Bouffard Jean , Yoon Juyoung 
Published: December 2017

AbstractN‐Heterocyclic carbene (NHC) boranes undergo oxidative hydrolysis to give imidazolium salts with excellent kinetic selectivity for HOCl over other reactive oxygen species (ROS), including peroxides and peroxynitrite. Selectivity for HOCl results from the electrophilic oxidation mechanism of NHC boranes, which stands in contrast to the nucleophilic oxidation mechanism of arylboronic acids with ROS. The change in polarity that accompanies the conversion of NHC boranes to imidazolium salts can control the formation of emissive excimers, forming the basis for the design of the first fluorescence probe for ROS based on the oxidation of B−H bonds. Two‐photon microscope (TPM) ratiometric imaging of HOCl in living cells and tissues is demonstrated.
A BN Aromatic Ring Strategy for Tunable Hydroxy Content in Polystyrene
Authors: van de Wouw Heidi L. , Lee Jae Young , Awuyah Elorm C. , Klausen Rebekka S. 
Published: December 2017

AbstractBN 2‐vinylnaphthalene, a BN aromatic vinyl monomer, is copolymerized with styrene under free radical conditions. Oxidation yields styrene–vinyl alcohol (SVA) statistical copolymers with tunable hydroxy group content. Comprehensive spectroscopic investigation provides proof of structure. Physical properties that vary systematically with hydroxy content include solubility and glass transition temperature. BN aromatic polymers represent a platform for the preparation of diverse functional polymeric architectures via the remarkable reaction chemistry of C−B bonds.
Brønsted Acid‐Catalyzed Carbonyl‐Olefin Metathesis inside a Self‐Assembled Supramolecular Host
Authors: Catti Lorenzo , Tiefenbacher Konrad 
Published: December 2017

AbstractCarbonyl–olefin metathesis represents a powerful yet underdeveloped method for the formation of carbon–carbon bonds. So far, no Brønsted acid based method for the catalytic carbonyl–olefin metathesis has been described. Herein, a cocatalytic system based on a simple Brønsted acid (HCl) and a self‐assembled supramolecular host is presented. The developed system compares well with the current benchmark catalyst for carbonyl–olefin metathesis in terms of substrate scope and yield of isolated product. Control experiments provide strong evidence that the reaction proceeds inside the cavity of the supramolecular host. A mechanistic probe indicates that a stepwise reaction mechanism is likely.
Evaluation of the Stability of DNA i‐Motifs in the Nuclei of Living Mammalian Cells
Authors: Dzatko Simon , Krafcikova Michaela , Hänsel‐Hertsch Robert , Fessl Tomas , Fiala Radovan , Loja Tomas , Krafcik Daniel , Mergny Jean‐Louis , Foldynova‐Trantirkova Silvie , Trantirek Lukas 
Published: December 2017

AbstractC‐rich DNA has the capacity to form a tetra‐stranded structure known as an i‐motif. The i‐motifs within genomic DNA have been proposed to contribute to the regulation of DNA transcription. However, direct experimental evidence for the existence of these structures in vivo has been missing. Whether i‐motif structures form in complex environment of living cells is not currently known. Herein, using state‐of‐the‐art in‐cell NMR spectroscopy, we evaluate the stabilities of i‐motif structures in the complex cellular environment. We show that i‐motifs formed from naturally occurring C‐rich sequences in the human genome are stable and persist in the nuclei of living human cells. Our data show that i‐motif stabilities in vivo are generally distinct from those in vitro. Our results are the first to interlink the stability of DNA i‐motifs in vitro with their stability in vivo and provide essential information for the design and development of i‐motif‐based DNA biosensors for intracellular applications.
Effect of different biopolymers and polymers on the mechanical and permeation properties of extruded PHBV cast films
Authors: Jost Verena , Miesbauer Oliver 
Published: December 2017

ABSTRACTThe biopolymer poly‐3‐hydroxybutyrate‐co‐3‐hydroxyvalerate (PHBV) is a promising material for packaging applications but its high brittleness is challenging. To address this issue, PHBV was blended with nine different biopolymers and polymers in order to improve the processing and mechanical properties of the films. Those biopolymers were TPS, PBAT, a blend of PBAT + PLA, a blend of PBAT + PLA + filler, PCL and PBS, and the polymers TPU, PVAc, and EVA. The extruded cast films were analyzed in detail (melting temperature, crystallinity, mechanical properties, permeation properties, and surface topography). A decrease in crystallinity and Young's modulus and an increase in elongation at break and permeability were observed with increasing biopolymer/polymer concentration. In PHBV‐rich blends (≥70 wt % PHBV), the biopolymers/polymers PCL, PBAT, and TPU increased the elongation at break while only slightly increasing the permeability. Larger increases in the permeability were found for the films with PBS, PVAc, and EVA. The films of biopolymer/polymer‐rich blends (with PBAT, TPU, and EVA) had significantly different properties than pure PHBV. A strong effect on the properties was measured assuming that at certain biopolymer/polymer concentrations the coherent PHBV network is disrupted. The interpretation of the permeation values by the Maxwell–Garnett theory confirms the assumption of a phase separation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46153.
Frequency of Chronic Joint Pain Following Chikungunya Virus Infection
Authors: Chang Aileen Y. , Encinales Liliana , Porras Alexandra , Pacheco Nelly , Reid St. Patrick , Martins Karen A. O. , Pacheco Shamila , Bravo Eyda , Navarno Marianda , Rico Mendoza Alejandro , Amdur Richard , Kamalapathy Priyanka , Firestein Gary S. , Bethony Jeffrey M. , Simon Gary L. 
Published: December 2017

ObjectiveTo estimate the frequency of chronic joint pain after infection with chikungunya virus in a Latin American cohort.MethodsA cross‐sectional follow‐up of a prospective cohort of 500 patients from the Atlántico Department, Colombia who were clinically diagnosed as having chikungunya virus during the 2014–2015 epidemic was conducted. Baseline symptoms and follow‐up symptoms at 20 months were evaluated in serologically confirmed cases.ResultsAmong the 500 patients enrolled, 485 had serologically confirmed chikungunya virus and reported joint pain status. Patients were predominantly adults (mean ± SD age 49 ± 16 years) and female, had an education level of high school or less, and were of Mestizo ethnicity. The most commonly affected joints were the small joints, including the wrists, ankles, and fingers. The initial virus symptoms lasted a median of 4 days (interquartile range [IQR] 3–8 days). Sixteen percent of the participants reported missing school or work (median 4 days [IQR 2–7 days]). After 20 months, one‐fourth of the participants had persistent joint pain. A multivariable analysis indicated that significant predictors of persistent joint pain included college graduate status, initial symptoms of headache or knee pain, missed work, normal activities affected, ≥4 days of initial symptoms, and ≥4 weeks of initial joint pain.ConclusionThis is the first report to describe the frequency of chikungunya virus–related arthritis in the Americas after a 20‐month follow‐up. The high frequency of chronic disease highlights the need for the development of prevention and treatment methods.
Adaptive Recurrent Neural Network Enhanced Variable Structure Control for Nonlinear Discrete Mimo Systems
Authors: Hwang Chih‐Lyang , Hung John Y. 
Published: December 2017

AbstractThe stability and performance of robust control for a nonlinear complex dynamic system deteriorates due to large uncertainties. To address this, a discrete variable structure control (DVSC) outside of a convex set is designed to force the operating point into a convergent set, which is verified by Lyapunov stability theory. Due to the dynamic features of the lumped uncertainties, they are learned on‐line by a recurrent neural network (RNN) in a specific convex set containing the convergent set of the DVSC. Between this convergent set and the convex set, a switching mechanism determines whether a learning RNN for the lumped uncertainties is executed. An adaptive recurrent‐neural‐network enhanced discrete variable structure control is then established to improve both transient and steady performances. Simulations, including compared examples and application to the trajectory tracking of a mobile robot, validate the effectiveness and robustness of the proposed control.
Immediate and late outcomes of stenting for severe extracranial internal carotid artery stenosis in octogenarian patients
Authors: Duan Jin‐hai , Xu Shu‐wen , Dai Chengbo , Xiao Hao , Zhong Jiayi , Ma Faxin , Mo Jian‐wei , Wang Shuyuan , Zhang Xiong , Lin Zhanyi 
Published: December 2017

AbstractBackgroundMultiple studies suggest that internal carotid artery stenting can be performed safely in octogenarians with low periprocedural complication rates. However, great concern still exists as to whether these patients will gain long‐term benefits from this procedure given their advanced age and uncertain life expectancy. We decided to conduct a retrospective study to determine short‐and long‐term clinical outcomes and to analyze survival duration in this population.Methods and ResultsSixty‐nine consecutive elderly patients with either symptomatic or asymptomatic stenosis ≥70% underwent 86 procedures. Immediate and late outcomes, as well as survival data, were analyzed retrospectively. Mean age was 83.1 ± 2.7 years. Mean survival was 49.3 ± 10.1 months. A complete neurological assessment was obtained at 1 and 2 years in 100% of patients, at 3 years in 90.7% of patients and at 5 years in 84.8% of patients. Two major and one minor ischemic strokes occurred during the periprocedural period. No death, myocardial infarction or intracranial hemorrhage was recorded. The mean follow‐up period was 55.4 ± 24.6 months. Four patients experienced a minimum of 1 year of follow‐up, and the longest is 8 years. Among the patients with the longest follow‐up time, 6 had ischemic strokes, of which 2 were fatal. In total, 17 deaths occurred. Four patients experienced dementia without stroke. Survival at 3 and 5 years was estimated to be 90% and 73%, respectively.ConclusionThis study demonstrated that stenting in octogenarians was safe and effective during the periprocedural period. Long‐term follow‐up showed a low rate of fatal and nonfatal stroke, and patients survived long enough to benefit from the procedure. However, it was associated with a relatively high rate of long‐term event. Though carotid artery stenting is a minimally invasive procedure, it should still be performed with great caution and only in carefully selected patients. The present study suggested that in this age population, carotid artery stenting might be considered as a revascularization option.
Both activated and less‐activated regions identified by functional MRI reconfigure to support task executions
Authors: Zuo Nianming , Yang Zhengyi , Liu Yong , Li Jin , Jiang Tianzi 
Published: December 2017

AbstractIntroductionFunctional magnetic resonance imaging (fMRI) has become very important for noninvasively characterizing BOLD signal fluctuations, which reflect the changes in neuronal firings in the brain. Unlike the activation detection strategy utilized with fMRI, which only emphasizes the synchronicity between the functional nodes (activated regions) and the task design, brain connectivity and network theory are able to decipher the interactive structure across the entire brain. However, little is known about whether and how the activated/less‐activated interactions are associated with the functional changes that occur when the brain changes from the resting state to a task state. What are the key networks that play important roles in the brain state changes?MethodsWe used the fMRI data from the Human Connectome Project S500 release to examine the changes of network efficiency, interaction strength, and fractional modularity contributions of both the local and global networks, when the subjects change from the resting state to seven different task states.ResultsWe found that, from the resting state to each of seven task states, both the activated and less‐activated regions had significantly changed to be in line with, and comparably contributed to, a global network reconfiguration. We also found that three networks, the default mode network, frontoparietal network, and salience network, dominated the flexible reconfiguration of the brain.ConclusionsThis study shows quantitatively that contributions from both activated and less‐activated regions enable the global functional network to respond when the brain switches from the resting state to a task state and suggests the necessity of considering large‐scale networks (rather than only activated regions) when investigating brain functions in imaging cognitive neuroscience.
The skin–kidney connection: bullous pemphigoid associated with acute allograft rejection and membranous nephropathy
Authors: Koratala Abhilash , Clapp William L. , Olaoye Olanrewaju A. , Santos Alfonso H. 
Published: December 2017

Key Clinical MessageBullous pemphigoid has been linked to allograft rejection, as well as membranous nephropathy in renal transplant recipients. Although there is a possibility of multiple distinct autoimmune processes, immune stimulation induced by allograft rejection or antibasement zone antibody interactions are possible mechanisms for the simultaneous skin and renal involvement.
Supramolecular Assembly of Phosphole Oxide Based Alkynylplatinum(II) 2,6‐Bis(N‐alkylbenzimidazol‐2’‐yl)pyridine Complexes—An Interplay of Hydrophobicity and Aromatic π‐Surfaces
Authors: Cheung Andy Fu‐Fai , Hong Eugene Yau‐Hin , Yam Vivian Wing‐Wah 
Published: December 2017

AbstractA new class of phosphole oxide based alkynylplatinum(II) 2,6‐bis(N‐alkylbenzimidazol‐2’‐yl)pyridine (bzimpy) complexes were synthesized and characterized. Their self‐assembly was driven by hydrophobic–hydrophobic and π–π stacking interactions. The self‐assembly properties were also investigated by UV/Vis absorption spectroscopy, which revealed that the alkyl‐chain length of the bzimpy moiety and the π‐surface area of the alkynyl ligand have significant influence on the overall self‐assembly process. The alkyl‐chain length also affected the morphological structures of the aggregates, which were studied by transmission electron microscopy and scanning electron microscopy.
Morphological Effects and Stabilization of the Metallic 1T Phase in Layered V‐, Nb‐, and Ta‐Doped WSe2 for Electrocatalysis
Authors: Chia Xinyi , Sutrisnoh Nur Ayu Afira , Sofer Zdeněk , Luxa Jan , Pumera Martin 
Published: December 2017

AbstractLayered transition‐metal dichalcogenides (TMDs) are valued for their electrocatalytic properties toward the hydrogen‐evolution reaction (HER) and oxygen‐reduction reaction (ORR). One effective strategy to activate the electrocatalytic properties of TMDs is through doping. The optimistic outlook of doped‐MoS2 as an electrocatalyst witnessed in previous reports spurred us to examine the effect of doping WSe2 with Group 5 transition‐metal species, namely V, Nb, and Ta, in aspects of inherent electroactivities and catalysis. Apart from the mild reduction signal unique to the Group 5 transition‐metal dopants, the Group 5 transition‐metal‐doped WSe2 materials are found to possess largely identical inherent electrochemistry to the undoped WSe2 with a characteristic anodic peak. Living up to expectations, the Group 5 transition‐metal‐doped WSe2 materials exhibit improved electrocatalytic HER efficiency, as evident by the lower HER overpotentials and Tafel slopes relative to undoped WSe2. After doping with V, Nb, or Ta species, an increased number of active sites is observed given the distinct changes in morphology from thick bulky pieces in undoped WSe2 to thinner fragments in doped WSe2. Although undoped WSe2 exists in the semiconducting 2H phase, the Group 5 transition‐metal‐doped WSe2 materials are dominated by the metallic 1T phase. Doping WSe2 with V, Nb, or Ta stabilizes the catalytic 1T phase and appears to induce the transition from the 2H to 1T phase. In contrast to the enhanced HER performance of WSe2 upon doping, Group 5 transition‐metal dopants proved futile in activating the ORR electrocatalytic behavior of WSe2, for which the ORR efficiency is unchanged. Therefore, these findings facilitate the understanding of the role of Group 5 transition‐metal dopants in the electrochemical and catalytic properties of WSe2 relative to their morphological features and provide an evaluation of the efficacy of doping TMDs in electrocatalytic applications.
Dithiocarboxylic Acids: An Old Theme Revisited and Augmented by New Preparative, Spectroscopic and Structural Facts
Authors: Grote Johanna , Friedrich Felix , Berthold Katarína , Hericks Loreen , Neumann Beate , Stammler Hans‐Georg , Mitzel Norbert W. 
Published: December 2017

AbstractThe unstable dithiocarboxylic acids dithioacetic acid, 2‐methyl‐dithiopropionic acid, 2,2‐dimethyl‐dithiopropionic acid and dithiobenzoic acid were synthesized and characterized by NMR spectroscopy and GC/MS. The stable dithiocarboxylic acids 2,4,6‐trimethyl benzoic acid, 2,4,6‐tri‐iso‐propylbenzoic acid and 2,6‐dimesityl benzoic acid were synthesized, isolated and characterized by spectroscopic methods and in parts by mass spectrometry and X‐ray crystallography. The new data were used to re‐evaluate literature data on the synthesis, spectroscopy and structural data of dithiocarboxylic acids as a fundamental class of organic compounds in general.