bluuebunny/crossref_metadata_2025 huggingface dataset:
In-plane electric field controlled perpendicular magnetic anisotropy in an FePt/[Pb(Mg1/3Nb2/3)O3]0.7–(PbTiO3)0.3 heterostructure
Authors: Guo Qi , Xu Xiaoguang , Feng Julong , Liu Pengfei , Wu Yong , Ma Li , Zhou Shiming , Miao Jun , Jiang Yong
Published: April 2016

We report the in-plane electric field controlled perpendicular magnetic anisotropy of L10-FePt films deposited on polarized [Pb(Mg1/3Nb2/3)O3]0.7–(PbTiO3)0.3 single crystal substrates. The out-of-plane coercivity (H
c⊥) of FePt films exhibits a regular response to the in-plane electric field applied on substrates. The experimental change of H
c⊥ is approximately 21.3% with the electric field varying from −10 to 10 kV/cm. The magnetization direction can be controlled by switching the electric field. The remanence of FePt films can also be manipulated by the electric field, so that a “W”-shaped sawtooth magnetic signal can be generated by a sawtooth electric field.
A low-temperature fabricated gate-stack structure for Ge-based MOSFET with ferromagnetic epitaxial Heusler-alloy/Ge electrodes
Authors: Fujita Yuichi , Yamada Michihiro , Nagatomi Yuta , Yamamoto Keisuke , Yamada Shinya , Sawano Kentarou , Kanashima Takeshi , Nakashima Hiroshi , Hamaya Kohei
Published: April 2016

A possible low-temperature fabrication process of a gate-stack for Ge-based spin metal–oxide–semiconductor field-effect transistor (MOSFET) is investigated. First, since we use epitaxial ferromagnetic Heusler alloys on top of the phosphorous doped Ge epilayer as spin injector and detector, we need a dry etching process to form Heusler-alloy/n+-Ge Schottky-tunnel contacts. Next, to remove the Ge epilayers damaged by the dry etching process, the fabricated structures are dipped in a 0.03% diluted H2O2 solution. Finally, Al/SiO2/GeO2/Ge gate-stack structures are fabricated at 300 °C as a top gate-stack structure. As a result, the currents in the Ge-MOSFET fabricated here can be modulated by applying gate voltages even by using the low-temperature formed gate-stack structures. This low-temperature fabrication process can be utilized for operating Ge spin MOSFETs with a top gate electrode.
Energy dispersive X-ray spectroscopy analysis of Si sidewall surface etched by deep-reactive ion etching
Authors: Matsutani Akihiro , Nishioka Kunio , Sato Mina
Published: April 2016

We investigated the composition of a passivation film on a sidewall etched by deep-reactive ion etching (RIE) using SF6/O2 and C4F8 plasma, by energy-dispersive X-ray (EDX) spectroscopy. It was found that the compositions of carbon and fluorine in the passivation film on the etched sidewall depend on the width and depth of the etched trench. It is important to understand both the plasma behavior and the passivation film composition to carry out fabrication by deep-RIE. We consider that these results of the EDX analysis of an etched sidewall will be useful for understanding plasma behavior in order to optimize the process conditions of deep-RIE.
The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms
Authors: Ezcurra Martín D.
Published: April 2016

The early evolution of archosauromorphs during the Permo-Triassic constitutes an excellent empirical case study to shed light on evolutionary radiations in deep time and the timing and processes of recovery of terrestrial faunas after a mass extinction. However, macroevolutionary studies of early archosauromorphs are currently limited by poor knowledge of their phylogenetic relationships. In particular, one of the main early archosauromorph groups that need an exhaustive phylogenetic study is “Proterosuchia,” which as historically conceived includes members of both Proterosuchidae and Erythrosuchidae. A new data matrix composed of 96 separate taxa (several of them not included in a quantitative phylogenetic analysis before) and 600 osteological characters was assembled and analysed to generate a comprehensive higher-level phylogenetic hypothesis of basal archosauromorphs and shed light on the species-level interrelationships of taxa historically identified as proterosuchian archosauriforms. The results of the analysis using maximum parsimony include a polyphyletic “Prolacertiformes” and “Protorosauria,” in which the PermianAenigmastropheusandProtorosaurusare the most basal archosauromorphs. The enigmatic choristoderans are either found as the sister-taxa of all other lepidosauromorphs or archosauromorphs, but consistently placed within Sauria. Prolacertids, rhynchosaurs, allokotosaurians and tanystropheids are the major successive sister clades of Archosauriformes. The Early TriassicTasmaniosaurusis recovered as the sister-taxon of Archosauriformes. Proterosuchidae is unambiguosly restricted to five species that occur immediately after and before the Permo-Triassic boundary, thus implying that they are a short-lived “disaster” clade. Erythrosuchidae is composed of eight nominal species that occur during the Early and Middle Triassic. “Proterosuchia” is polyphyletic, in which erythrosuchids are more closely related toEuparkeriaand more crownward archosauriforms than to proterosuchids, and several species are found widespread along the archosauromorph tree, some being nested within Archosauria (e.g., “Chasmatosaurus ultimus,”Youngosuchus). Doswelliids and proterochampsids are recovered as more closely related to each other than to other archosauromorphs, forming a large clade (Proterochampsia) of semi-aquatic to aquatic forms that includes the bizarre genusVancleavea.Euparkeriais one of the sister-taxa of the clade composed of proterochampsians and archosaurs. The putative Indian archosaurYarasuchusis recovered in a polytomy withEuparkeriaand more crownward archosauriforms, and as more closely related to the RussianDongusuchusthan to other species. Phytosaurs are recovered as the sister-taxa of all other pseudosuchians, thus being nested within Archosauria.
Phylogenetic position of Meteoromyrtus (Myrtaceae)
Authors: Wilson Peter G , Heslewood Margaret M
Published: April 2016

We investigated the phylogenetic affinities of the rare and threatened Indian species Meteoromyrtus wynadensis (Bedd.) Gamble. Sequences from the ITS and ETS regions of nrDNA and the trnK/matK and psbA–trnH regions of the plastid genome were compiled in a 45 taxon dataset augmented by sequences from Genbank. Phylogenetic analysis using maximum parsimony and Bayesian approaches showed that Meteoromyrtus is deeply embedded in Eugenia and sister to E. reinwardtiana in a clade with other Old World taxa. The evidence clearly indicates that the genus should be considered a synonym of Eugenia and that the species should henceforth be known by its original name E. wynadensis Bedd.
Posteruptive impacts of pyroclastic deposits from basaltic andesite stratovolcanoes on surface water composition
Authors: Genareau K. , Cronin S. J. , Stewart C. , Bhattacharyya S. , Donahoe R.
Published: April 2016

Volcanic ash deposition following explosive eruptions can pose significant hazards for water quality, human health, agriculture, and infrastructure functionality. Many studies have examined how fresh ash deposition may lower the pH of, and introduce a range of potentially toxic elements into, exposed surface waters. However, no study has yet determined the effects on water composition as a result of mechanical pyroclast disaggregation and production of new fresh particle surfaces and increasingly fine grained particles. Such disaggregation could result from natural posteruptive processes such as debris avalanches, lahars, or fluvial/aeolian transport and human activities such as cleanup efforts or mining of pyroclastic deposits. The posteruption time scales of pyroclast disaggregation may vary from months in moist tropical or temperate environments to years or decades in arid settings. Here we show, for the first time in experimental studies, that mechanical milling of pyroclasts will introduce a range of elements into exposed waters, including Al, which can be toxic at elevated levels, and Na, which increases the electrical conductivity of solutions. The pH of leaching solutions also increases by several log units. Such dramatic changes on the experimental scale may have implications for surface water composition in posteruptive settings, necessitating longer‐term risk assessments for ecosystem health and consideration of the role of pyroclastic deposits in element cycling in volcanically active regions.
Acceleration of groundwater remediation by deep sweeps and vortex ejections induced by rapidly pulsed pumping
Authors: Kahler David M. , Kabala Zbigniew J.
Published: April 2016

One key limiting factor to groundwater remediation is contaminant sequestered in pores whose contents do not mix well with the bulk flow. Mixing between well‐connected (pores whose volume is flushed as water flows through the aquifer) and poorly connected pores (pores whose volume does not exchange readily when water flows through the aquifer) is of primary concern. Under steady flow, contaminants are effectively trapped in the poorly connected pores and are transferred only by molecular diffusion. This slow mixing process between pore types is a bottleneck to remediation. We present a novel rapidly pulsed pumping method that increases the mixing between these pore types. We do it in the context of pump‐and‐treat remediation because it is the most common remediation practice. In rapidly pulsed pumping, the increase in flow causes a deep sweep, which pushes the flow into poorly connected pores and sweeps out sequestered contaminants. The decrease in flow causes a vortex ejection, which causes the vortex within the poorly connected pore to emerge with contaminant. These actions are modeled with computational fluid mechanics to elucidate the individual mechanisms and determine how they function and interact. Cleanup of single and multiple poorly connected pore systems were simulated and show the acceleration possible. This technique can decrease the time and cost needed to remediate contaminated aquifers, which in the United States has been estimated to exceed $1 trillion. Since our rapidly pulsed pumping method enhances mixing between well‐connected and poorly connected pores, it can be applied to other remediation schemes such as in situ methods.
High‐resolution modeling of coastal freshwater discharge and glacier mass balance in the Gulf of Alaska watershed
Authors: Beamer J. P. , Hill D. F. , Arendt A. , Liston G. E.
Published: April 2016

A comprehensive study of the Gulf of Alaska (GOA) drainage basin was carried out to improve understanding of the coastal freshwater discharge (FWD) and glacier volume loss (GVL). Hydrologic processes during the period 1980–2014 were modeled using a suite of physically based, spatially distributed weather, energy‐balance snow/ice melt, soil water balance, and runoff routing models at a high‐resolution (1 km horizontal grid; daily time step). Meteorological forcing was provided by the North American Regional Reanalysis (NARR), Modern Era Retrospective Analysis for Research and Applications (MERRA), and Climate Forecast System Reanalysis (CFSR) data sets. Streamflow and glacier mass balance modeled using MERRA and CFSR compared well with observations in four watersheds used for calibration in the study domain. However, only CFSR produced regional seasonal and long‐term trends in water balance that compared favorably with independent Gravity Recovery and Climate Experiment (GRACE) and airborne altimetry data. Mean annual runoff using CFSR was 760 km3 yr−1, 8% of which was derived from the long‐term removal of stored water from glaciers (glacier volume loss). The annual runoff from CFSR was partitioned into 63% snowmelt, 17% glacier ice melt, and 20% rainfall. Glacier runoff, taken as the sum of rainfall, snow, and ice melt occurring each season on glacier surfaces, was 38% of the total seasonal runoff, with the remaining runoff sourced from nonglacier surfaces. Our simulations suggests that existing GRACE solutions, previously reported to represent glacier mass balance alone, are actually measuring the full water budget of land and ice surfaces.
Premature mortality in India due to PM2.5 and ozone exposure
Authors: Ghude Sachin D. , Chate D. M. , Jena C. , Beig G. , Kumar R. , Barth M. C. , Pfister G. G. , Fadnavis S. , Pithani Prakash
Published: April 2016

This bottom‐up modeling study, supported by new population census 2011 data, simulates ozone (O3) and fine particulate matter (PM2.5) exposure on local to regional scales. It quantifies, present‐day premature mortalities associated with the exposure to near‐surface PM2.5 and O3 concentrations in India using a regional chemistry model. We estimate that PM2.5 exposure leads to about 570,000 (CI95: 320,000–730,000) premature mortalities in 2011. On a national scale, our estimate of mortality by chronic obstructive pulmonary disease (COPD) due to O3 exposure is about 12,000 people. The Indo‐Gangetic region accounts for a large part (~42%) of the estimated mortalities. The associated lost life expectancy is calculated as 3.4 ± 1.1 years for all of India with highest values found for Delhi (6.3 ± 2.2 years). The economic cost of estimated premature mortalities associated with PM2.5 and O3 exposure is about 640 (350–800) billion USD in 2011, which is a factor of 10 higher than total expenditure on health by public and private expenditure.
Decorin‐mediated inhibition of the migration of U87MG glioma cells involves activation of autophagy and suppression of TGF‐β signaling
Authors: Yao Ting , Zhang Chen‐guang , Gong Ming‐tao , Zhang Min , Wang Lei , Ding Wei
Published: April 2016

Decorin (DCN) is a major member of the small leucine‐rich proteoglycan (SLRP) family that is critically involved in tumorigenesis and the development of metastasis of cancers, including glioma. Overexpression of DCN was indicated to suppress glioma cell growth. However, the role of DCN in the migration of glioma cells remain elusive. In this study, we found that treatment with exogenous DCN inhibited the adhesion and migration of U87MG glioma cells with down‐regulation of TGF‐β signaling. DCN also activated autophagy, as indicated by monodansylcadaverine (MDC) staining, increase in LC3 I/LC3 II conversion, and p62/SQSTM1 degradation in U87MG cells. The increased activity of autophagy was found to be connected to the inhibition on glioma cell migration. Knockdown of DCN expression or the disruption of autophagy with 3‐methyladenine (3‐MA) was able to reduce the suppression on cell adhesion and migration induced by DCN. When U87MG cells were treated with temozolomide (TMZ), induction of autophagy and up‐regulation of DCN were observed, accompanied by suppressed cell adhesion and migration. Transfection of siRNA targeting DCN attenuated the suppressive effect of TMZ on glioma cell migration and adhesion. Our results indicated that the migration of glioma cells was under the control of the active status of autophagy, with DCN serving as a key player, as well as an indicator of the outcome. Therefore, it is suggested that autophagy‐modulating reagents could be considered for the treatment of invasive glioma.
Violent media and hostile appraisals: A meta‐analytic review
Authors: Bushman Brad J.
Published: April 2016

Hostile people tend to view the world as a hostile place. Although there are individual differences in hostile world‐views, situational factors can also play a role. For example, scenes of violence in the mass media might influence people to view the world as a hostile place. This meta‐analysis aggregates, for the first time, all studies that have investigated the link between exposure to violent media and hostile appraisals (e.g., perceiving the ambiguous actions by others as aggressive actions). This meta‐analysis included 37 independent studies involving 10,410 participants. The results showed a “small” to “moderate” sized average correlation between exposure to violent media and hostile appraisals (r+ = .20, 95%CI = .14, .26). Significant correlations were found in experimental, cross‐sectional, and longitudinal studies, indicating a triangulation of evidence. Effects were not correlated with participant gender. Effects were also stable over time. However, the link between exposure to violent media and hostile appraisals was positively related to age, perhaps because violent media can have cumulative effects over time. There was no evidence of publication bias. The findings from this meta‐analysis are consistent with the General Aggression Model (e.g., Anderson, & Bushman, 2002; Annual Review of Psychology 53:27–51). These results compliment those from previous meta‐analyses showing that violent media can increase aggressive thoughts, angry feelings, physiological arousal, and aggressive behavior. These findings also have practical significance, because people who view the world in a hostile manner are more likely to behave aggressively themselves. Aggr. Behav. 42:605–613, 2016. © 2016 Wiley Periodicals, Inc.
“It's the Way That You Do It”: Developing an Ethical Framework for Community Psychology Research and Action
Authors: Campbell Rebecca
Published: April 2016

In the 50 years since the 1965 Swampscott conference, the field of community psychology has not yet developed a well‐articulated ethical framework to guide research and practice. This paper reviews what constitutes an “ethical framework”; considers where the field of community psychology is at in its development of a comprehensive ethical framework; examines sources for ethical guidance (i.e., ethical principles and standards) across multiple disciplines, including psychology, evaluation, sociology, and anthropology; and recommends strategies for developing a rich written discourse on how community psychology researchers and practitioners can address ethical conflicts in our work.
Metal‐Free Aminooxygenation of Alkynes: Efficient Synthesis of 3‐Aroylimidazo[1,2‐a]‐N‐Heterocycles
Authors: Reddy K. Ranjith , Gupta Ajai Prakash , Das Parthasarathi
Published: April 2016

An expeditious, one‐pot, N‐iodosuccinimide‐promoted reaction has been developed for the synthesis of 3‐aroylimidazo[1,2‐a]pyridines from 3‐phenylpropiolaldehyde and 2‐aminopyridines.This aminooxygenation process of alkynes is general and was successfully extended to access 3‐aroylimidazo[1,2‐a]pyrazines and 3‐aroylimidazo[1,2‐b]pyridazines. With the metal‐free conditions and great efficiency in expanding molecule diversity, this method is superior to the existing procedures in the synthesis of 3‐aroylimidazo[1,2‐a]‐N‐heterocycles.
C3 Alkylation of Indoles Catalyzed by Carbocations under Continuous‐Flow Conditions
Authors: Wan Li , Zhu Wentong , Qiao Kai , Sun Xiaoning , Fang Zheng , Guo Kai
Published: April 2016

A fast and practical protocol for the C3 alkylation of varied indole substrates catalyzed by carbocations was developed under continuous‐flow conditions. Because of the enhanced mass‐ and heat‐transfer features of the microreactor, the reaction time was significantly reduced compared with batch conditions. The functional group tolerance of this method is good, the substrate scope for indoles and α,β‐unsaturated carbonyls is broad. In addition, the reactants were employed in the ratio of 1:1 to achieve good to excellent yields. It is an effective reaction to cut down chemical waste and is of benefit for environment protection from an industrial production point of view.
Anthranil: An Aminating Reagent Leading to Bifunctionality for Both C(sp3)−H and C(sp2)−H under Rhodium(III) Catalysis
Authors: Yu Songjie , Tang Guodong , Li Yingzi , Zhou Xukai , Lan Yu , Li Xingwei
Published: April 2016

Previous direct C−H nitrogenation suffered from simple amidation/amination with limited atom‐economy and is mostly limited to C(sp2)−H substrates. In this work, anthranil was designed as a novel bifunctional aminating reagent for both C(sp2)−H and C(sp3)−H bonds under rhodium(III) catalysis, thus affording a nucleophilic aniline tethered to an electrophilic carbonyl. A tridendate rhodium(III) complex has been isolated as the resting state of the catalyst, and DFT studies established the intermediacy of a nitrene species.
Engineering Stacks of V‐Shaped Polyaromatic Compounds with Alkyl Chains for Enhanced Emission in the Solid State
Authors: Sekiguchi Shoya , Kondo Kei , Sei Yoshihisa , Akita Munetaka , Yoshizawa Michito
Published: April 2016

A V‐shaped bisanthracene derivative with three butyl groups formed two types of emissive solids that display bluish green and blue fluorescence (ΦF=72 and 32 %, respectively), depending on the preparation conditions. The crystal and powder X‐ray analyses reveal that the highly emissive solid adopts a head‐to‐head arrangement with discrete stacks of the anthracene moieties, whereas the moderately emissive solid adopts a head‐to‐tail arrangement without the stacks. The obtained molecular arrangements are transformed by thermal stimuli accompanying the change in fluorescence. Furthermore, large enhancements of dye emissions (12–45‐fold) through highly efficient host–guest energy transfer were achieved in the solid state by adding minute amounts of various fluorescent dyes (e.g. rubrene and Nile red) to the V‐shaped compound.
Effect of thermal annealing on the mechanical and thermal properties of polylactic acid–cellulosic fiber biocomposites
Authors: Pérez‐Fonseca A. A. , Robledo‐Ortíz J. R. , González‐Núñez R. , Rodrigue D.
Published: April 2016

Polylactic acid (PLA) biocomposites were produced by a combination of extrusion and injection molding with three cellulosic reinforcements (agave, coir, and pine) and contents (10, 20, and 30%). In particular, some samples were subjected to thermal annealing (105 °C for 1 h) to modify the crystallinity of the materials. In all cases, morphological (scanning electron microscopy) and thermal (differential scanning calorimetry, dynamical mechanical thermal analysis) characterizations were related to the mechanical properties (Charpy impact, tensile and flexural tests). The results showed that annealing increased the crystallinity for all the materials produced, but different mechanical behaviors were observed depending on fiber type and content. For example, annealing increased the impact strength and flexural modulus of PLA and PLA biocomposites (agave, coir, and pine), while decreasing their flexural strength. But the main conclusion is that fiber addition combined with thermal annealing can substantially increase the thermal stability of the studied materials. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43750.
Hypervalent‐Iodine(III)‐Mediated Oxidative Methodology for the Synthesis of Fused Triazoles
Authors: Kamal Raj , Kumar Vipan , Kumar Ravinder
Published: April 2016

The organic chemistry of hypervalent organoiodine compounds has been an area of unprecedented development. This surge in interest in the use of hypervalent iodine compounds has mainly been owing to their highly selective oxidizing properties, environmentally benign character and commercial availability. Hypervalent iodine reagents have also been used as an alternative to toxic heavy metals, owing to their low toxicity and ease of handling. Hypervalent organoiodine(III) reagents are versatile oxidants that have been successfully employed to extend the scope of selective oxidative transformations of complex organic molecules in synthetic chemistry. This Focus Review concerns the tandem in situ generation and 1,5‐electrocyclization of N‐heteroaryl nitrilimines into fused triazoles. We describe the importance of recently developed hypervalent‐organoiodine(III)‐catalyzed oxidative cyclization reactions, building towards the conclusion that hypervalent iodine chemistry is a promising frontier for oxidative cyclization, in particular of hydrazones, for the synthesis of fused triazoles.
Facile Hydrazine‐Hydrothermal Syntheses and Characterizations of Two Quaternary Thioarsenates(III): Two‐Dimensional SrAg4As2S6⋅2 H2O and One‐Dimensional BaAgAsS3
Authors: Yan Dongming , Liu Chang , Chai Wenxiang , Zheng Xuerong , Zhang Luodong , Zhi Mingjia , Zhou Chunmei , Zhang Qichun , Liu Yi
Published: April 2016

Two new quaternary thioarsenates(III), SrAg4As2S6⋅2 H2O (1) and BaAgAsS3 (2), have been prepared through a hydrazine‐hydrothermal method at low temperature. Compound 1 possesses a two‐dimensional (2D) layer network, while compound 2 features a one‐dimensional (1D) column structure. The detailed structure analysis indicates that Sr2+ and Ba2+ cations have different directing effects on the structures of thioarsenates(III). Both experimental and theoretical studies demonstrate that compounds 1 and 2 are narrow‐gap semiconductors. Our success in synthesizing these two quaternary thioarsenates(III) proves that the hydrazine‐hydrothermal technique is a powerful yet facile synthetic method for exploring new complex chalcogenides with diverse crystal structures and interesting physical properties.
Preparation of Magnetic Tubular Nanoreactors for Highly Efficient Catalysis
Authors: Yang Shuliang , Peng Li , Cao Changyan , Wei Fang , Liu Jian , Zhu Ya‐Nan , Liu Chang , Wang Xiaoshi , Song Weiguo
Published: April 2016

We report an efficient and controllable route to prepare magnetic tubular nanoreactors composed of a mesoporous SiO2 shell with iron‐noble metal nanoparticles inside. The key of this method is to design and fabricate Fe nanoparticles encapsulated in a mesoporous SiO2 shell. Making use of a galvanic replacement reaction between Fe and noble metal ions, all of the noble metal nanoparticles are loaded inside the mesoporous SiO2 shell, and thus nanoreactors are formed. Taking Pd as an example, the prepared Pd−Fe@meso‐SiO2 tubular nanoreactor exhibits a high catalytic activity and excellent reusability for styrene hydrogenation under mild conditions. This study provides a facile route to fabricate magnetic nanoreactors with enhanced catalytic properties.
On the link between cold fronts and hail in Switzerland
Authors: Schemm Sebastian , Nisi Luca , Martinov Andrey , Leuenberger Daniel , Martius Olivia
Published: April 2016

Hail is the costliest atmospheric hazard in Switzerland, causing substantial damage to agriculture, cars and buildings every year. In this study, a 12‐year statistic of objectively identified cold fronts and a radar‐based hail statistic are combined to investigate the co‐occurrence of cold fronts and hail in Switzerland. In a first step, an automated front identification scheme, which has previously been designed for and applied to global reanalysis data, is modified for a high‐resolution regional analysis data set. This front detection method is then adapted, tested and applied to the Consortium for Small Scale Modelling (COSMO) analysis data for the extended hail season (May to September) in the years 2002–2013. The resulting cold front statistic is presented and discussed. In a second step, the frequency of cold fronts is linked to a high‐resolution radar‐based hail statistic to determine the relative fraction of hail initiation events in pre‐frontal environments. Up to 45% of all detected hail events in north‐eastern and southern Switzerland form in pre‐frontal zones. Similar fractions are identified upstream of the Jura and the Black Forest mountains. The percentage of front‐related hail formation is highest in regions where hail is statistically less frequent, with the exception of southern Switzerland. Furthermore, it is shown that fronts create wind‐sheared environments, which are favourable for hail cells.
Propensities of peptides containing the Asn‐Gly segment to form β‐turn and β‐hairpin structures
Authors: Kang Young Kee , Yoo In Kee
Published: April 2016

The propensities of peptides that contain the Asn‐Gly segment to form β‐turn and β‐hairpin structures were explored using the density functional methods and the implicit solvation model in CH2Cl2 and water. The populations of preferred β‐turn structures varied depending on the sequence and solvent polarity. In solution, β‐hairpin structures with βI′ turn motifs were most preferred for the heptapeptides containing the Asn‐Gly segment regardless of the sequence of the strands. These preferences in solution are consistent with the corresponding X‐ray structures. The sequence, H‐bond strengths, solvent polarity, and conformational flexibility appeared to interact to determine the preferred β‐hairpin structure of each heptapeptide, although the β‐turn segments played a role in promoting the formation of β‐hairpin structures and the β‐hairpin propensity varied. In the heptapeptides containing the Asn‐Gly segment, the β‐hairpin formation was enthalpically favored and entropically disfavored at 25°C in water. The calculated results for β‐turns and β‐hairpins containing the Asn‐Gly segment imply that these structural preferences may be useful for the design of bioactive macrocyclic peptides containing β‐hairpin mimics and the design of binding epitopes for protein–protein and protein–nucleic acid recognitions. © 2016 Wiley Periodicals, Inc. Biopolymers 105: 653–664, 2016.
Prognostic significance of carotid and vertebral ultrasound in ischemic stroke patients
Authors: Muscari Antonio , Bonfiglioli Andrea , Magalotti Donatella , Puddu Giovanni M. , Zorzi Veronica , Zoli Marco
Published: April 2016

Objectives

The ultrasound investigation of carotid and vertebral arteries is routinely performed in stroke patients to determine the etiopathogenetic classification and possible need of revascularization. However, the medium and long‐term prognostic implications of carotid and vertebral ultrasound in ischemic stroke patients are not yet known.

Methods

This study included 309 ischemic stroke patients (mean age 76.3; 160 men). They all had undergone carotid and vertebral ultrasound (carotid stenoses were measured according to the European Carotid Surgery Trial [ECST] method). After a median interval of 9.4 months, a telephone follow‐up was performed to determine their outcome. Dependency or death (modified Rankin scale‐mRS >2) and all cause mortality were the study end‐points.

Results

At follow‐up, 158 patients had a mRS >2. In multivariate analysis, of 13 variables univariately predictive of dependency or death, only National Institutes of Health Stroke Scale (NIHSS) score (P < 0.0001), age (P < 0.0001) and ipsi‐ or contralateral carotid stenosis ≥60% (O.R. 3.5, 95% C.I. 1.5–8.6, P = 0.006) remained associated with a mRS >2. Sixty‐nine patients had died. In a Cox proportional hazards regression, of 10 variables univariately predictive of mortality, only NIHSS score (P < 0.0001), age (P = 0.003), total anterior circulation syndrome (P = 0.004), vertebral Doppler abnormalities (O.R. 2.2, 95% C.I. 1.3–3.6, P = 0.006), male sex (P = 0.02), and hypercholesterolemia (P = 0.04, inverse relationship) remained associated with mortality.

Conclusions

In stroke patients, carotid stenoses ≥60%, ipsi‐ or contralateral to cerebral lesions, were associated with an increased medium and long‐term probability of dependency or death, and abnormalities of vertebrobasilar flow were a significant indicator of death risk, independent of stroke severity and age.
Enhanced Heat Stability of α‐Chymotrypsin through Single‐Enzyme Confinement in Attoliter Liposomes
Authors: Yoshimoto Makoto , Yamada Jun , Baba Misaki , Walde Peter
Published: April 2016

The entrapment of α‐chymotrypsin (α‐CT) within 70–140 nm liposomes formed from POPC (1‐palmitoyl‐2‐oleoyl‐sn‐glycero‐3‐phosphocholine) leads to an unexpected and remarkable increase in the thermal stability of the enzyme. This finding is based on the observation that heating aqueous suspensions of α‐CT‐containing POPC liposomes to 80 °C for 30 minutes resulted in partial enzyme inactivation, whereas the same treatment of aqueous solutions of free α‐CT inactivated the enzyme completely. The stabilizing effect of enzyme confinement in the attoliter volumes of the liposomes was found to increase with decreasing numbers of α‐CT molecules per liposome. Single‐enzyme confinement was particularly effective, as intermolecular interactions between heat‐denatured α‐CT molecules (causing irreversible inactivation) are not possible.
Nucleoside‐Based Diarylethene Photoswitches: Synthesis and Photochromic Properties
Authors: Wang Hai‐Xia , Xi Dan‐Dan , Xie Ming‐Sheng , Wang Hui‐Xuan , Qu Gui‐Rong , Guo Hai‐Ming
Published: April 2016

Diarylethene photoswitches based on the natural nucleoside deoxyadenosine were designed and synthesized. In aqueous solution, some of them exhibited good photochromic properties, including clear changes in color upon irradiation at 365 nm, red‐shifts of the absorption wavelength, with good fatigue resistance, thermal stability, conversion efficiency, and base‐pairing properties.
Study design and rationale of the heterotopic implantation of the Edwards‐Sapien XT transcatheter valve in the inferior VEna cava for the treatment of severe tricuspid regurgitation (HOVER) trial
Authors: O'Neill Brian P. , Wheatley Grayson , Bashir Riyaz , Edmundowicz Daniel , O'Murchu Brian , O'Neill William W. , Patil Pravin , Chen Andrew , Forfia Paul , Cohen Howard A.
Published: April 2016

Background

Tricuspid regurgitation (TR) is an under treated disease. Although surgery for TR remains an effective therapy, many patients are considered to be at a high risk or otherwise inoperable. Caval valve implant (CAVI) offers an alternative to surgery in these patients. Trials assessing the safety and efficacy of caval valve implant are lacking. Methods: The Heterotopic Implantation Of the Edwards‐Sapien XT Transcatheter Valve in the Inferior VEna cava for the treatment of severe Tricuspid Regurgitation (HOVER) trial is an FDA approved, physician initiated, prospective, non‐blinded (open label), non‐randomized safety and feasibility study to determine the safety and efficacy of the heterotopic implantation of the Edwards‐Sapien XT valve in the inferior vena cava for the treatment of severe TR in patients who are at high risk or inoperable. Patients with severe TR in the absence of severe pulmonary hypertension will be recruited. They will be evaluated by a multi‐disciplinary team who will agree by consensus that the patients’ symptoms are from TR. They will undergo imaging to assess the size of the inferior vena cava (IVC) to determine feasibility of the procedure. If patients meet the inclusion criteria and are free from exclusion criteria, after informed consent they will be eligible for enrollment in the study. A total of 30 patients will be enrolled. The primary objective of the study will be to demonstrate procedural success at 30‐days and patient success at 1‐year. Conclusion: Caval valve implant may present an alternative for patients who are at high risk or inoperable for tricuspid valve surgery (TVS) for TR. © 2016 Wiley Periodicals, Inc.
A novel maneuver to facilitate retrograde wire externalization during retrograde chronic total occlusion percutaneous coronary intervention
Authors: Carlino Mauro , Azzalini Lorenzo , Colombo Antonio
Published: April 2016

Background

Although the retrograde approach has improved the success rate and procedural efficiency of chronic total occlusion (CTO) percutaneous coronary intervention (PCI), it can still be challenging and time‐consuming. We introduce a novel technique that aims to facilitate the critical step of retrograde wire externalization during reverse controlled antegrade and retrograde tracking and dissection (CART), which we named DRAFT (Deflate, Retract and Advance into the Fenestration Technique).

Materials and Methods

DRAFT is performed by simultaneous retraction of the deflating antegrade balloon (after inflation in the subintimal space) and advancement of the retrograde looped wire in the same plane through the transient fenestrations created by reverse CART, in order to cross through the fenestrated dissection flap before its collapse. The retrograde wire is then quickly and easily advanced into the antegrade guiding catheter.

Results

DRAFT was used in 11 patients (8 with right coronary artery and 3 with left anterior descending artery CTOs). Several different guidewires were used, since this technique does not need any specific wire to be performed. DRAFT was successful in all cases, after at most five attempts. CTO PCI was then completed as per standard retrograde practice. No complications occurred.

Conclusions

DRAFT is a versatile approach that allows easy and quick re‐entry of the retrograde wire into the true lumen during reverse CART. It can be performed with a variety of guidewires and is feasible both in the left and right coronary arteries. © 2016 Wiley Periodicals, Inc.
TriGuard™ HDH embolic deflection device for cerebral protection during transcatheter aortic valve replacement
Authors: Samim Mariam , van der Worp Bart , Agostoni Pierfrancesco , Hendrikse Jeroen , Budde Ricardo P.J. , Nijhoff Freek , Ramjankhan Faiz , Doevendans Pieter A. , Stella Pieter R.
Published: April 2016

Objectives

This study aims to evaluate the safety and performance of the new embolic deflection device TriGuard™HDH in patients undergoing TAVR.

Background

Transcatheter aortic valve replacement (TAVR) is associated with a high incidence of new cerebral ischemic lesions. The use of an embolic protection device may reduce the frequency of TAVR‐related embolic events.

Methods

This prospective, single arm feasibility pilot study included 14 patients with severe symptomatic aortic stenosis scheduled for TAVR. Cerebral diffusion weighted magnetic resonance imaging (DWI) was planned in all patients one day before and at day 4 (±2) after the procedure. Major adverse cerebral and cardiac events (MACCEs) were recorded for all patients. Primary endpoints of this study were I) device performance success defined as coverage of the aortic arch takeoffs throughout the entire TAVR procedure and II) MACCE occurrence. Secondary endpoints included the number and the volume of new cerebral ischemic lesions on DWI.

Results

Thirteen patients underwent transfemoral TAVR and one patient a transapical procedure. Edwards SAPIEN valve prosthesis was implanted in 8 (57%) patients and Medtronic CoreValve prosthesis in the remaining 6 (43%). Predefined performance success of the TriGuard™HDH device was achieved in 9 (64%) patients. The composite endpoint MACCE occurred in none of the patients. Post‐procedural DWI was performed in 11 patients. Comparing the DWI of these patients to a historical control group showed no reduction in number [median 5.5 vs. 5.0, P = 0.857], however there was a significant reduction in mean lesion volume per patient [median 13.8 vs. 25.1, P = 0.049].

Conclusion

This study showed the feasibility and safety of using the TriGuard™HDH for cerebral protection during TAVR. This device did not decrease the number of post‐procedural new cerebral DWI lesions, however its use showed decreased lesion volume as compared to unprotected TAVR. © 2016 Wiley Periodicals, Inc.
Three‐Dimensional Coral‐Like Structure Constructed of Carbon‐Coated Interconnected Monocrystalline SnO2 Nanoparticles with Improved Lithium‐Storage Properties
Authors: Xu Wangwang , Cui Xiaodan , Xie Zhiqiang , Dietrich Grant , Wang Ying
Published: April 2016

The applications of alloying/dealloying materials as anode for LIB electrode are hindered by its dramatic volume variations and sluggish kinetics. Herein, to overcome these challenges, we report a facile and scalable approach fabricating coral‐like SnO2/C composite electrodes through a top‐down strategy followed by a sol–gel carbon‐coating method. During the synthesis, well‐defined SnS2 nanoflowers and dopamine serve as structural template and carbon source for integrating the desired structure. The three‐dimensional coral‐like SnO2/C composite exhibits a high reversible capacity of 648 mAh g−1 after 50 electrochemical cycles and a low capacity fading of 0.778 % per cycle from the 2nd to the 50th cycle, demonstrating an outstanding cycling stability. It also shows a discharge capacity of 1294, 784, 658, 532, and 434 mAh g−1 at a specific current of 100, 200, 500, 1000 and 2000 mAh g−1, respectively, and retains a specific capacity of 719 mAh g−1 when the specific current goes back to 100 mA g−1, displaying an excellent rate capability. Compared to SnS2 nanoflowers and bare interconnected SnO2 nanoparticles anode, the optimized coral‐like SnO2/C composite shows significantly improved electrochemical performances in terms of rate capability and cycling reversibility, demonstrating great potential as superior anodes in next‐generation lithium ion batteries.
A Hydrogen‐Bonded Organic‐Framework‐Derived Mesoporous N‐Doped Carbon for Efficient Electroreduction of Oxygen
Authors: Liu Ji , Li Ligui , Niu Wenhan , Wang Nan , Zhao Dengke , Zeng Shuaibo , Chen Shaowei
Published: April 2016

Direct carbonization methods represent a facile strategy for the synthesis of functional carbon electrocatalysts, however, the resulting carbons are mostly microporous and of low surface area, which disfavor mass transfer, and usually have low electrocatalytic activity. In this study, a hydrogen‐bonded organic framework (HOF) comprising of melamine and trimesic acid is used as a highly porous precursor to prepare N‐doped carbons through facile, direct pyrolysis. The high nitrogen content of melamine and the intrinsically porous nature of the HOF facilitates the formation of a mesoporous carbon with 4.8 atom % content of nitrogen dopants and a significantly high surface area of 1321 m2 g−1. Electrochemical measurements show that the best sample, which was pyrolyzed at 800 °C (HOF‐800), exhibited efficient catalytic activity for oxygen electroreduction in 0.1 m KOH aqueous solution. This catalyst exhibits a much more positive onset potential, higher diffusion‐limited current density, higher electron‐transfer number in the low overpotential region, higher stability, and stronger tolerance against methanol crossover than the state‐of‐the‐art Pt/C catalysts. The results in this study suggest the potential of intrinsically porous HOFs for the development of highly efficient nonprecious‐metal electrocatalysts.
Effect of Photoinduced Size Changes on Protein Refolding and Transport Abilities of Soft Nanotubes
Authors: Kameta Naohiro , Akiyama Haruhisa , Masuda Mitsutoshi , Shimizu Toshimi
Published: April 2016

Self‐assembly of azobenzene‐modified amphiphiles (GlynAzo, n=1–3) in water at room temperature in the presence of a protein produced nanotubes with the protein encapsulated in the channels. The Gly2Azo nanotubes (7 nm internal diameter [i.d.]) promoted refolding of some encapsulated proteins, whereas the Gly3Azo nanotubes (13 nm i.d.) promoted protein aggregation. Although the 20 nm i.d. channels of the Gly1Azo nanotubes were too large to influence the encapsulated proteins, narrowing of the i.d. to 1 nm by trans‐to‐cis photoisomerization of the azobenzene units of the Gly1Azo monomers packed in the solid bilayer membranes led to a squeezing out of the proteins into the bulk solution and simultaneously enhanced their refolding ratios. In contrast, photoinduced transformation of the Gly2Azo nanotubes to short nanorings (<40 nm) with a large i.d. (28 nm) provided no further refolding assistance. We thus demonstrate that pertubation by the solid bilayer membrane wall of the nanotubes is important to accelerate refolding of the denatured proteins during their transport in the narrow nanotube channels.
Phenanthro[4,5‐fgh]quinoxaline‐Fused Subphthalocyanines: Synthesis, Structure, and Spectroscopic Characterization
Authors: Pan Houhe , Liu Wenbo , Wang Chiming , Wang Kang , Jiang Jianzhuang
Published: April 2016

A series of four phenanthro[4,5‐fgh]quinoxaline‐fused subphthalocyanine derivatives 0–3 containing zero, one, two, and three phenanthro[4,5‐fgh]quinoxaline moieties, respectively, were isolated from the mixed cyclotrimerization reaction of 2,9‐di‐tert‐butylphenanthro[4,5‐fgh]quinoxaline‐5,6‐dicarbonitrile with 4,5‐bis(2,6‐diisopropylphenoxy)phthalonitrile and characterized by a series of spectroscopic methods including MALDI‐TOF mass, 1H NMR, electronic absorption, magnetic circular dichroism (MCD), and fluorescence spectroscopy. The molecular structures for the compounds 0 and 2 were clearly revealed on the basis of single‐crystal X‐ray diffraction analysis. Their electrochemical properties were also studied by cyclic voltammetry. In particular, theoretical calculations in combination with the electronic absorption and electrochemical analyses revealed the significant influence of the fused‐phenanthro[4,5‐fgh]quinoxaline units on the electronic structures.
Gold‐Catalyzed Reaction of ortho‐Alkynylarylaldehydes with Conjugated Dienes: An Efficient Access to Highly Strained Tetracyclic Bridgehead Olefins
Authors: Cao Ziping , Zhu Hongbo , Meng Xin , Tian Laijin , Sun Xuejun , Chen Guang , You Jinmao
Published: April 2016

An unprecedented access to strained tetracyclic bridgehead alkenes by reaction of easily accessible ortho‐alkynylarylaldehydes with conjugated dienes is described. The process involves a chemo‐ and stereo‐selective, gold‐catalyzed, tandem intermolecular [3+2] cycloaddition/Prins‐type ring‐closing reaction that allows generating structural complexity in a straightforward manner. This approach for the preparation of anti‐Bredt compounds is synthetically superior to those previously reported: the procedure is easy to implement, operates under mild experimental conditions, is efficient, and exhibits a good substrate scope.
Practical Stannylation of Allyl Acetates Catalyzed by Nickel with Bu3SnOMe
Authors: Komeyama Kimihiro , Itai Yuuhei , Takaki Ken
Published: April 2016

A practical and scalable nickel‐catalyzed allylic stannylation of allyl acetates with Bu3SnOMe is described. A variety of acyclic and cyclic allyl acetates, even with base‐sensitive moieties, undergoes the stannylation by using NiBr2/4,4′‐di‐tert‐butylbipyridine (dtbpy)/Mn catalyst system to afford highly functionalized allyl stannanes with excellent regioselectivity and yields. Furthermore, the scope of protocol is also extended by the reaction of propargyl acetates, giving rise to propargyl or allenyl stannanes. Additionally, a unique diastereoselectivity using the nickel catalyst different from the palladium was demonstrated for the stannylation of cyclic allyl acetates. In the reaction, inexpensive and stable nickel complexes, abundant reductant (Mn), and atom‐economical stannyl source were used.
Synthesis and DFT Study of a Diphenylsilanone‐Bridged Dimolybdenum Complex
Authors: Alvarez M. Angeles , García M. Esther , García‐Vivó Daniel , Menéndez Sonia , Ruiz Miguel A.
Published: April 2016

Reaction of the 30‐electron benzylidyne complex [Mo2Cp2(μ‐CPh)(μ‐PCy2)(μ‐CO)] with excess Ph2SiH2under visible‐UV irradiation yields the silylene‐bridged complex [Mo2Cp2(μ‐CPh)(μ‐PCy2)(μ‐SiPh2)]. This compound undergoes selective oxidation with O2to give the unsaturated complex [Mo2Cp2(μ‐CPh)(μ‐PCy2)(μ‐κ1:κ1‐OSiPh2)], which contains an unprecedented bridging diphenylsilanone ligand, as confirmed by X‐ray diffraction analysis and DFT calculations. The bonding within the central Mo2SiO ring of this complex approaches the extreme description of a dimetallacyclosiloxane according to the relevant solid‐state bond lengths and theoretical calculations.
A Photo‐Triggered Traceless Staudinger–Bertozzi Ligation Reaction
Authors: Hu Peng , Feng Tianshi , Yeung Chi‐Chung , Koo Chi‐Kin , Lau Kai‐Chung , Lam Michael H. W.
Published: April 2016

The use of light to control the course of a chemical/biochemical reaction is an attractive idea because of its ease of administration with high precision and fine spatial resolution. Staudinger ligation is one of the commonly adopted conjugation processes that involve a spontaneous reaction between azides and arylphosphines to form iminophosphoranes, which further hydrolyze to give stable amides. We designed an anthracenylmethyl diphenylphosphinothioester (1) that showed promising Staudinger ligation reactivity upon photo‐excitation. Broadband photolysis at 360–400 nm in aqueous organic solvents induced heterolytic cleavage of its anthracenylmethyl–phosphorus bond, releasing a diphenylphosphinothioester (2) as an efficient traceless Staudinger–Bertozzi ligation reagent. The quantum yield of such a photo‐induced heterolytic bond‐cleavage at the optimal wavelength of photolysis (376 nm) at room temperature is ≥0.07. This work demonstrated the feasibility of photocaging arylphosphines to realize the photo‐triggering of the Staudinger ligation reaction.