bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tailored Porous ZnCo2O4 Nanofibrous Electrocatalysts for Lithium–Oxygen Batteries
Authors: Kim Jae‐Chan , Lee Gwang‐Hee , Lee Seun , Oh Seung‐Ik , Kang Yongku , Kim Dong‐Wan 
Published: December 2017

AbstractLithium‐oxygen batteries are considered a next‐generation technology owing to their extremely high theoretical energy density despite many challenges such as low round‐trip efficiency and poor cyclability. The air‐cathode structure and pore properties play a key role in solving these problems. In this study, we fabricate ZnCo2O4 nanofibers and design a porous nanostructure using a facile electrospinning process and selective etching of ZnO as the cathode material in lithium‐oxygen batteries. First, non‐porous ZnCo2O4 nanofiber electrodes accomplish high catalytic activity and good cycling stability during 116 cycles with a limited capacity of 1000 mA h g−1 at a current density of 500 mA g−1. For enhanced catalytic activity and cyclability, ZnO included ZnCo2O4 nanofibers are prepared using a Zn‐excess electrospun solution and porous ZnCo2O4 nanofibers are fabricated via selective etching of ZnO. Porous ZnCo2O4 nanofiber electrodes exhibit excellent electrocatalytic activity and cyclability for 226 cycles with a limited capacity of 1000 mA h g−1 at a current density of 500 mA g−1. The exceptional catalytic properties explain the synergistic effect of the one‐dimensional nanostructure and porous structure with an appropriate pore diameter, providing a large active site and an efficient electron pathway during the Li2O2 formation/decomposition process.
Oxidant‐Mediated Nitrogenation and Recyclization of Imidazo[1,2‐a]pyridines with Sodium Azide: Synthesis of 4H‐Pyrido[1,2‐a][1,3,5]triazin‐4‐ones
Authors: Cao Gangjian , Chen Zhengkai , Song Jinyu , Xu Jianfeng , Miao Maozhong , Ren Hongjun 
Published: December 2017

AbstractAn expeditious and straightforward approach for the synthesis of 4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐ones starting from readily available imidazo[1,2‐a]pyridines and sodium azide has been presented under aerobic oxidative conditions. The reaction proceeded well with the promotion of potassium persulfate/potassium permanganate with good functional group tolerance. A wide range of biologically valuable 4H‐pyrido[1,2‐a][1,3,5]triazin‐4‐one scaffolds were assembled by this methodology. The gram‐scale reaction was also achieved. A cascade nitrogenation and oxidative recyclization sequence could be involved in the reaction.magnified image
Calcium Doping Facilitates Water Dissociation in Magnesium Oxide
Authors: Müller Danny , Knoll Christian , Ruh Thomas , Artner Werner , Welch Jan M. , Peterlik Herwig , Eitenberger Elisabeth , Friedbacher Gernot , Harasek Michael , Blaha Peter , Hradil Klaudia , Werner Andreas , Weinberger Peter 
Published: December 2017

AbstractCalcium doping of magnesium oxide results in significantly increased water dissociation rates, thus enhancing both hydration rate and reaction completeness of hydration compared to pure MgO. For a series of mixed magnesium–calcium oxides (MgxCa1−xO) with varying Ca contents between 0% and 40%, the material of a composition Mg0.9Ca0.1O shows the fastest rehydration, transforming completely within 80 min to the mixed hydroxide. In consecutive dehydration/rehydration cycles, reasonable cycle stability is found. A “regeneration” of the aged material (reactivity reduced by excessive cycling) in liquid water re‐establishes the initial rehydration reactivity. Density functional theory calculations support the experimental findings, confirming that calcium doping can reduce the energy of the rate limiting water dissociation reaction, exploiting both electronic and steric (size) effects.
Nanoimaging of Electronic Heterogeneity in Bi2Se3 and Sb2Te3 Nanocrystals
Authors: Lu Xiaowei , Khatib Omar , Du Xutao , Duan Jiahua , Wei Wei , Liu Xianli , Bechtel Hans A. , D'Apuzzo Fausto , Yan Mingtao , Buyanin Alexander , Fu Qiang , Chen Jianing , Salmeron Miquel , Zeng Jie , Raschke Markus B. , Jiang Peng , Bao Xinhe 
Published: December 2017

AbstractTopological insulators (TIs) are quantum materials with topologically protected surface states surrounding an insulating bulk. However, defect‐induced bulk conduction often dominates transport properties in most TI materials, obscuring the Dirac surface states. In order to realize intrinsic topological insulating properties, it is thus of great significance to identify the spatial distribution of defects, understand their formation mechanism, and finally control or eliminate their influence. Here, the electronic heterogeneity in polyol‐synthesized Bi2Se3 and chemical vapor deposition‐grown Sb2Te3 nanocrystals is systematically investigated by multimodal atomic‐to‐mesoscale resolution imaging. In particular, by combining the Drude response sensitivity of infrared scattering‐type scanning near‐field optical microscopy with the work‐function specificity of mirror electron microscopy, characteristic mesoscopic patterns are identified, which are related to carrier concentration modulation originating from the formation of defects during the crystal growth process. This correlative imaging and modeling approach thus provides the desired guidance for optimization of growth parameters, crucial for preparing TI nanomaterials to display their intrinsic exotic Dirac properties.
Age is a predictor of a small decrease in lung function in children with sickle cell anemia
Authors: Willen Shaina M. , Cohen Robyn , Rodeghier Mark , Kirkham Fenella , Redline Susan S. , Rosen Carol , Kirkby Jane , DeBaun Michael R. 
Published: December 2017

AbstractThe longitudinal pattern of lung function in children with sickle cell anemia (SCA) has shown a decrease in FEV1% predicted, a risk factor for death in adults with SCA, but predictors for this decline are poorly characterized. In a prospective longitudinal multi‐center cohort of children with SCA, we tested the hypotheses that: (1) FEV1% predicted declines over time; and (2) SCA‐specific characteristics and therapy predict this decline. At three clinical centers, children with SCA (HbSS or HbSβ0 thalassemia), unselected for respiratory disease, were enrolled in the Sleep and Asthma Cohort (SAC) study. Study‐certified pulmonary function technicians performed spirometry and lung volumes. Each assessment was reviewed centrally. Predicted values were determined for TLC, FEV1, FVC, and FEV1/FVC ratio. A total of 197 participants, mean age 11.0 years at first testing (range 4‐19.3 years), had a minimum of three spirometry measurements, over an average of 4.4 years (range 1.1‐6.5 years) from baseline to endpoint. In a multivariable model, FEV1% predicted declines by 0.3% for every additional year of age (95% CI −0.56 to −0.05, P = .020). Sex, asthma history, hemoglobin, reticulocyte count, white blood cell count, incidence rate of severe acute pain and acute chest syndrome episodes, and hydroxyurea therapy were not associated with a decline in FEV1% predicted. In a large, rigorously evaluated, prospective cohort of an unselected group of children with SCA, FEV1% predicted declines minimally over an average of 4 years, and none of the examined disease features predict the decline.
Similar outcome of allogeneic stem cell transplantation after myeloablative and sequential conditioning regimen in patients with refractory or relapsed acute myeloid leukemia: A study from the Société Francophone de Greffe de Moelle et de Thérapie Cellulaire
Authors: Decroocq Justine , Itzykson Raphaël , Vigouroux Stéphane , Michallet Mauricette , Yakoub‐Agha Ibrahim , Huynh Anne , Beckerich Florence , Suarez Felipe , Chevallier Patrice , Nguyen‐Quoc Stéphanie , Ledoux Marie‐Pierre , Clement Laurence , Hicheri Yosr , Guillerm Gaëlle , Cornillon Jérôme , Contentin Nathalie , Carre Martin , Maillard Natacha , Mercier Mélanie , Mohty Mohamad , Beguin Yves , Bourhis Jean‐Henri , Charbonnier Amandine , Dauriac Charles , Bay Jacques‐Olivier , Blaise Didier , Deconinck Eric , Jubert Charlotte , Raus Nicole , Peffault de Latour Regis , Dhedin Nathalie 
Published: December 2017

AbstractPatients with acute myeloid leukemia (AML) in relapse or refractory to induction therapy have a dismal prognosis. Allogeneic hematopoietic stem cell transplantation is the only curative option. In these patients, we aimed to compare the results of a myeloablative transplant versus a sequential approach consisting in a cytoreductive chemotherapy followed by a reduced intensity conditioning regimen and prophylactic donor lymphocytes infusions. We retrospectively analyzed 99 patients aged 18‐50 years, transplanted for a refractory (52%) or a relapsed AML not in remission (48%). Fifty‐eight patients received a sequential approach and 41 patients a myeloablative conditioning regimen. Only 6 patients received prophylactic donor lymphocytes infusions. With a median follow‐up of 48 months, 2‐year overall survival was 39%, 95% confidence interval (CI) (24‐53) in the myeloablative group versus 33%, 95% CI (21‐45) in the sequential groups (P = .39), and 2‐year cumulative incidence of relapse (CIR) was 57% versus 50% respectively (P = .99). Nonrelapse mortality was not higher in the myeloablative group (17% versus 15%, P = .44). In multivariate analysis, overall survival, CIR and nonrelapse mortality remained similar between the two groups. However, in multivariate analysis, sequential conditioning led to fewer acute grade II‐IV graft versus host disease (GVHD) (HR for sequential approach = 0.37; 95% CI: 0.21‐0.65; P < .001) without a significant impact on chronic GVHD (all grades and extensive). In young patients with refractory or relapsed AML, myeloablative transplant and sequential approach offer similar outcomes except for a lower incidence of acute GvHD after a sequential transplant.
DHEAS patterning across childhood in three sub‐Saharan populations: Associations with age, sex, ethnicity, and cortisol
Authors: Helfrecht Courtney , Hagen Edward H. , DeAvila David , Bernstein Robin M. , Dira Samuel J. , Meehan Courtney L. 
Published: December 2017

AbstractObjectivesHormones have many roles in human ontogeny, including the timing of life history ‘switch points’ across development. Limited hormonal data exist from non‐Western children, leaving a significant gap in our understanding of the diversity of life history patterning. This cross‐sectional study examines dehydroepiandrosterone sulfate (DHEAS) production in relation to age, sex, ethnicity, and cortisol concentrations, as well as average age of adrenarche, among Aka and Ngandu children of the Central African Republic and Sidama children of Ethiopia.MethodsHair was collected from 480 children (160 per population) aged 3‐18 years old. These samples were analyzed for DHEAS and cortisol concentrations using ELISAs. A generalized additive model was used to examine DHEAS patterning in relation to age, sex, cortisol, and ethnicity. The derivative of DHEAS as a function of age was used to identify average age of adrenarche in each population.ResultsDHEAS patterning in these three populations is distinct from Euro‐American patterns of production. In all three groups, the population‐level age at adrenarche onset occurs slightly later than Euro‐American averages, with both Central African populations experiencing a later onset than the Ethiopian population.ConclusionsDHEAS patterns and age at adrenarche vary across cultures, perhaps indicating adaptive life history responses in diverse eco‐cultural environments. Delayed involution of the fetal zone and DHEAS patterning may offer both cognitive protection and immune defense in high‐risk, nutritionally‐poor environments. Additional research in the majority world is essential to improving our understanding of the diversity of hormonal development and timing of ‘switch points’ in life history trajectories.
Job insecurity and depression among automobile sales workers: A longitudinal study in South Korea
Authors: Kim Yugyun , Kim Seung‐Sup 
Published: December 2017

BackgroundJob insecurity, the subjective perception of fear due to uncertainty about job continuity, could have long‐term health effects. We aimed to examine the effect of job insecurity on depression among automobile sales workers in South Korea.MethodsWe analyzed data collected in 2007 and 2014 from a longitudinal cohort of 560 sales workers from an automobile company in South Korea. Change in job insecurity was classified into four groups: secure to secure; insecure to secure; secure to insecure; and insecure to insecure.ResultsAfter adjusting for potential confounders, workers in the insecure to insecure group had a significantly higher likelihood of depression in 2014 than workers in the secure to secure group (OR: 2.74; 95%CI: 1.41, 5.31).ConclusionsWe found that chronic job insecurity may be a risk factor for developing depression among Korean automobile sales workers. This is the first longitudinal study examining the association between job insecurity and depression in South Korea.
A Bioresistant Nitroxide Spin Label for In‐Cell EPR Spectroscopy: In Vitro and In Oocytes Protein Structural Dynamics Studies
Authors: Karthikeyan Ganesan , Bonucci Alessio , Casano Gilles , Gerbaud Guillaume , Abel Sébastien , Thomé Virginie , Kodjabachian Laurent , Magalon Axel , Guigliarelli Bruno , Belle Valérie , Ouari Olivier , Mileo Elisabetta 
Published: December 2017

AbstractApproaching protein structural dynamics and protein–protein interactions in the cellular environment is a fundamental challenge. Owing to its absolute sensitivity and to its selectivity to paramagnetic species, site‐directed spin labeling (SDSL) combined with electron paramagnetic resonance (EPR) has the potential to evolve into an efficient method to follow conformational changes in proteins directly inside cells. Until now, the use of nitroxide‐based spin labels for in‐cell studies has represented a major hurdle because of their short persistence in the cellular context. The design and synthesis of the first maleimido‐proxyl‐based spin label (M‐TETPO) resistant towards reduction and being efficient to probe protein dynamics by continuous wave and pulsed EPR is presented. In particular, the extended lifetime of M‐TETPO enabled the study of structural features of a chaperone in the absence and presence of its binding partner at endogenous concentration directly inside cells.
Light‐Driven C−H Oxygenation of Methane into Methanol and Formic Acid by Molecular Oxygen Using a Perfluorinated Solvent
Authors: Ohkubo Kei , Hirose Kensaku 
Published: December 2017

AbstractThe chlorine dioxide radical (ClO2.) was found to act as an efficient oxidizing agent in the aerobic oxygenation of methane to methanol and formic acid under photoirradiation. Photochemical oxygenation of methane occurred in a two‐phase system comprising perfluorohexane and water under ambient conditions (298 K, 1 atm). The yields of methanol and formic acid were 14 and 85 %, respectively, with a methane conversion of 99 % without formation of the further oxygenated products such as CO2 and CO. Ethane was also photochemically converted into ethanol (19 %) and acetic acid (80 %). The methane oxygenation is initiated by the photochemical Cl−O bond cleavage of ClO2. to generate Cl. and O2. The produced Cl. reacts with CH4 to form a methyl radical (CH3.). Finally, the oxygenated products such as methanol and formic acid were given by the radical chain reaction. A fluorous solvent plays an important role of inhibiting the deactivation of reactive radical species such as Cl. and CH3..
Copper‐Catalyzed Enantioselective Markovnikov Protoboration of α‐Olefins Enabled by a Buttressed N‐Heterocyclic Carbene Ligand
Authors: Cai Yuan , Yang Xin‐Tuo , Zhang Shuo‐Qing , Li Feng , Li Yu‐Qing , Ruan Lin‐Xin , Hong Xin , Shi Shi‐Liang 
Published: December 2017

AbstractReported is a highly enantioselective copper‐catalyzed Markovnikov protoboration of unactivated terminal alkenes. A variety of simple and abundant feedstock α‐olefins bearing a diverse array of functional groups and heterocyclic substituents can be used as substrates, and the reaction proceeds under mild reaction conditions at ambient temperature to provide expedient access to enantioenriched alkylboronic esters in good regioselectivity and with excellent enantiocontrol. Critical to the success of the protocol was the development and application of a novel, sterically hindered N‐heterocyclic carbene, (R,R,R,R)‐ANIPE, as the ligand for copper.
Dicarboxylic Acid Separation by Dynamic and Size‐Matched Recognition in Solution and in the Solid State
Authors: Kumar Vijith , Pilati Tullio , Terraneo Giancarlo , Ciancaleoni Gianluca , Macchioni Alceo , Resnati Giuseppe , Metrangolo Pierangelo 
Published: December 2017

AbstractBis(trimethylammonium) alkane diiodides dynamically encapsulate dicarboxylic acids through intermolecular hydrogen bonds between the I− anions of the hosts and the carboxylic OH groups of the guests. A selective recognition is realized when the size of the I−⋅⋅⋅HOOC(CH2/CF2)nCOOH⋅⋅⋅I− superanion matches the dication alkyl chain length. Dynamic recognition is also demonstrated in solution, where the presence of the size‐matching organic salt boosts the acid solubility profile, thus allowing efficient mixture separation.
Thioketone‐Directed Palladium(II)‐Catalyzed C−H Arylation of Ferrocenes with Aryl Boronic Acids
Authors: Cai Zhong‐Jian , Liu Chen‐Xu , Gu Qing , You Shu‐Li 
Published: December 2017

AbstractA palladium(II)‐catalyzed thioketone‐chelation‐assisted direct C−H arylation of ferrocenes is described. With thioketone as an efficient directing group, various monoaryl‐ and diaryl‐substituted thiocarbonylferrocenes were obtained by palladium‐catalyzed direct C−H functionalization in high yields under mild and base‐free reaction conditions. Furthermore, the arylated thiocarbonylferrocene could undergo diverse transformations.
Building Organic/Inorganic Hybrid Interphases for Fast Interfacial Transport in Rechargeable Metal Batteries
Authors: Zhao Qing , Tu Zhengyuan , Wei Shuya , Zhang Kaihang , Choudhury Snehashis , Liu Xiaotun , Archer Lynden A. 
Published: December 2017

AbstractWe report a facile in situ synthesis that utilizes readily accessible SiCl4 cross‐linking chemistry to create durable hybrid solid–electrolyte interphases (SEIs) on metal anodes. Such hybrid SEIs composed of Si‐interlinked OOCOR molecules that host LiCl salt exhibit fast charge‐transfer kinetics and as much as five‐times higher exchange current densities, in comparison to their spontaneously formed analogues. Electrochemical analysis and direct optical visualization of Li and Na deposition in symmetric Li/Li and Na/Na cells show that the hybrid SEI provides excellent morphological control at high current densities (3–5 mA cm−2) for Li and even for notoriously unstable Na metal anodes. The fast interfacial transport attributes of the SEI are also found to be beneficial for Li‐S cells and stable electrochemical cycling was achieved in galvanostatic studies at rates as high as 2 C. Our work therefore provides a promising approach towards rational design of multifunctional, elastic SEIs that overcome the most serious limitations of spontaneously formed interphases on high‐capacity metal anodes.
ortho‐Directing Chromium Arene Complexes as Efficient Mediators for Enantiospecific C(sp2)–C(sp3) Cross‐Coupling Reactions
Authors: Bigler Raphael , Aggarwal Varinder K. 
Published: December 2017

AbstractA new strategy for the coupling of a broad scope of electronically diverse aromatics to boronic esters is reported. The coupling sequence, which relies on the directed ortho‐lithiation of chromium arene complexes followed by boronate formation and oxidation, occurs with complete ortho‐selectivity and enantiospecificity to give the coupling products in excellent yields and with high functional group tolerance. An intermediate chromium arene boronate complex was characterized by X‐ray, NMR, and IR experiments to elucidate the reaction mechanism.
Mixed phase Fe2O3/Mn3O4 magnetic nanocomposite for enhanced adsorption of methyl orange dye: Neural network modeling and response surface methodology optimization
Authors: Bhowmik Mahashweta , Deb Krishna , Debnath Animesh , Saha Biswajit 
Published: December 2017

In this research, a novel magnetic mesoporous adsorbent with mixed phase of Fe2O3/Mn3O4 nanocomposite was prepared by a facile precipitating method and characterized extensively. The prepared nanocomposite was used as adsorbent for toxic methyl orange (MO) dye removal from aqua matrix considering its high surface area (178.27 m2/g) with high saturation magnetization (23.07 emu/g). Maximum dye adsorption occurs at solution pH 2.0 and the electrostatic attraction between anionic form of MO dye molecules and the positively charged nanocomposite surface is the main driving force behind this adsorption. Response surface methodology (RSM) was used for optimizing the process variables and maximum MO removal of 97.67% is obtained at optimum experimental condition with contact time, adsorbent dose and initial MO dye concentration of 45 min, 0.87 g/l and 116 mg/l, respectively. Artificial neural network (ANN) model with optimum topology of 3–5–1 was developed for predicting the MO removal (%), which has shown higher predictive ability than RSM model. Maximum adsorption capacity of this nanocomposite was found to be 322.58 mg/g from Langmuir isotherm model. Kinetic studies reveal the applicability of second‐order kinetic model with contribution of intra‐particle diffusion in this process.
Solid‐phase organic synthesis of chiral, non‐racemic 1,2,4‐trisubstituted 1,4‐diazepanes with high σ1 receptor affinity
Authors: Fanter Lena , Schepmann Dirk , Wünsch Bernhard 
Published: December 2017

AbstractThe aim of this work was to transfer the established chiral‐pool synthesis of 1,2,4‐trisubstituted 1,4‐diazepanes in solution on the solid phase. For this purpose, (S)‐configured amino acids, (S)‐alanine, and (S)‐leucine, with a small methyl and a larger isobutyl moiety were attached to the solid support 9 by reductive amination. After five reaction steps on the solid support, the 1,4‐diazepanes (S)‐19a,b were cleaved off and reductively alkylated to afford the 1,2,4‐trisubstituted 1,4‐diazepanes (S)‐20a and (S)‐21b, respectively. Both compounds show high σ1 affinity and selectivity over the σ2 subtype.
Block Copolymer Self‐Assembly in Solution—Quo Vadis?
Authors: Brendel Johannes C. , Schacher Felix H. 
Published: December 2017

AbstractThe desire to increase complexity while maintaining control over every aspect of the process itself might be used as a provocative description of the developments in block copolymer self‐assembly in solution over the last decade. The community has witnessed tremendous progress, not only with regard to the design of building blocks, but also in terms of understanding assembly pathways, interfacial properties, or kinetic obstacles. In particular, the latter can be of interest (and actually turned into an advantage) if structures that are not in thermodynamic equilibrium are targeted. Within this focus review, we aim to highlight the key developments and trends that we have identified during the last five years: the development of step‐wise and dynamic processes, different means to impart further hierarchy into solution‐borne nanostructures, and a partial shift in focus towards gradient and bottlebrush block copolymers.