bluuebunny/crossref_metadata_2025_split huggingface dataset:
Constructing Ordered Three‐Dimensional TiO2 Channels for Enhanced Visible‐Light Photocatalytic Performance in CO2 Conversion Induced by Au Nanoparticles
Authors: Xue Hairong , Wang Tao , Gong Hao , Guo Hu , Fan Xiaoli , Gao Bin , Feng Yaya , Meng Xianguang , Huang Xianli , He Jianping 
Published: January 2018

AbstractAs a typical photocatalyst for CO2 reduction, practical applications of TiO2 still suffer from low photocatalytic efficiency and limited visible‐light absorption. Herein, a novel Au‐nanoparticle (NP)‐decorated ordered mesoporous TiO2 (OMT) composite (OMT‐Au) was successfully fabricated, in which Au NPs were uniformly dispersed on the OMT. Due to the surface plasmon resonance (SPR) effect derived from the excited Au NPs, the TiO2 shows high photocatalytic performance for CO2 reduction under visible light. The ordered mesoporous TiO2 exhibits superior material and structure, with a high surface area that offers more catalytically active sites. More importantly, the three‐dimensional transport channels ensure the smooth flow of gas molecules, highly efficient CO2 adsorption, and the fast and steady transmission of hot electrons excited from the Au NPs, which lead to a further improvement in the photocatalytic performance. These results highlight the possibility of improving the photocatalysis for CO2 reduction under visible light by constructing OMT‐based Au‐SPR‐induced photocatalysts.
High‐definition transcranial direct current stimulation (HD‐tDCS) of left dorsolateral prefrontal cortex affects performance in Balloon Analogue Risk Task (BART)
Authors: Guo Heng , Zhang Zhuoran , Da Shu , Sheng Xiaotian , Zhang Xichao 
Published: January 2018

AbstractBackgroundStudies on risk preferences have long been of great concern and have examined the neural basis underlying risk‐based decision making. However, studies using conventional transcranial direct current stimulation (tDCS) revealed that bilateral stimulation could change risk propensity with limited evidence of precisely focalized unilateral high‐definition transcranial direct current stimulation (HD‐tDCS). The aim of this experiment was to investigate the effect of HD‐tDCS focalizing the left dorsal lateral prefrontal cortex (DLPFC) on risk‐taking behavior during the Balloon Analogue Risk Task (BART).MethodsThis study was designed as a between‐subject, single‐blind, sham‐controlled experiment. University students were randomly assigned to three groups: the anodal group (F3 anode, AF3, F1, F5, FC3 returned), the cathodal group (F3 cathodal, AF3, F1, F5, FC3 returned) and the sham group. Subsequently, 1.5‐mA 20‐min HD‐tDCS was applied during the BART, and the Positive Affect and Negative Affect Scale (PANAS), the Sensation Seeking Scale‐5 (SSS‐5), and the Behavioral Inhibition System and Behavioral Approach System scale (BIS/BAS) were measured as control variables.ResultsThe cathodal group earned less total money than the sham group, and no significant difference was observed between the anodal group and the sham group.ConclusionsThese results showed that, to some extent, focalized unilateral cathodal HD‐tDCS on left DLPFC could change performance during risky tasks and diminish risky decision making. Further studies are needed to investigate the dose effect and electrode distribution of HD‐tDCS during risky tasks and examine synchronous brain activity to show the neural basis.
Randomized comparison of novel biodegradable polymer and durable polymer‐coated cobalt‐chromium sirolimus‐eluting stents: Three‐Year Outcomes of the I‐LOVE‐IT 2 Trial
Authors: Song Lei , Li Jing , Guan Changdong , Jing Quanmin , Lu Shuzheng , Yang Lixia , Xu Kai , Yang Yuejin , Xu Bo , Han Yaling ,   on behalf of the I‐LOVE‐IT 2 Investigators
Published: January 2018

AbstractObjectivesWe aimed to compare the long‐term outcomes of the novel biodegradable polymer cobalt‐chromium sirolimus‐eluting stent (BP‐SES) versus the durable polymer sirolimus‐eluting stent (DP‐SES) in the I‐LOVE‐IT2 trial.BackgroundsComparisons of the long‐term safety and efficiency of the BP‐DES versus the DP‐DES are limited.MethodsA total of 2,737 patients eligible for coronary stenting were randomized to the BP‐SES or DP‐SES group at a 2:1 ratio. The primary endpoint of target lesion failure (TLF) was defined as a composite of cardiac death, target vessel myocardial infarction (MI), or clinically indicated target lesion revascularization.ResultsA three‐year clinical follow‐up period was available for 2,663 (97.3%) patients. There were no significant differences in TLF (8.9% vs. 8.6%, P = 0.81), patient‐oriented composite endpoint (PoCE) (15.2% vs.14.5%, P = 0.63), or individual components between the BP‐SES and DP‐SES. Definite/probable stent thrombosis (ST) was low and similar at 3 years (0.8% vs. 1.0%, P = 0.64). Landmark analysis of 1–3 years showed that the TLF (2.7% vs. 2.6%, P = 0.81), PoCE (6.2% vs. 5.1%, P = 0.28), and definite/probable ST (0.4% vs. 0.4%, P = 1.00) were comparable between the 2 arms.ConclusionsIn this prospective randomized trial, the BP‐SES showed similar clinical results versus the DP‐SES in terms of safety and efficacy outcomes over a 3‐year follow‐up period.
Design and Synthesis of A‐Ring Simplified Pyripyropene A Analogues as Potent and Selective Synthetic SOAT2 Inhibitors
Authors: Ohtawa Masaki , Arima Shiho , Ichida Naoki , Terayama Tomiaki , Ohno Hironao , Yamazaki Takaya , Ohshiro Taichi , Sato Noriko , Omura Satoshi , Tomoda Hiroshi , Nagamitsu Tohru 
Published: January 2018

AbstractCurrently, pyripyropene A, which is isolated from the culture broth of Aspergillus fumigatus FO‐1289, is the only compound known to strongly and selectively inhibit the isozyme sterol O‐acyltransferase 2 (SOAT2). To aid in the development of new cholesterol‐lowering or anti‐atherosclerotic agents, new A‐ring simplified pyripyropene A analogues have been designed and synthesized based on total synthesis, and the results of structure–activity relationship studies of pyripyropene A. Among the analogues, two A‐ring simplified pyripyropene A analogues exhibited equally efficient SOAT2 inhibitory activity to that of natural pyripyropene A. These new analogues are the most potent and selective SOAT2 inhibitors to be used as synthetic compounds and attractive seed compounds for the development of drug for dyslipidemia, including atherosclerotic disease and steatosis.
Interactions between Clinically Used Bisphosphonates and Bone Mineral: from Coordination Chemistry to Biomedical Applications and Beyond
Authors: Gałęzowska Joanna 
Published: January 2018

AbstractBisphosphonates (BPs) are well‐established, widely used first‐choice drugs for bone‐related diseases and are one of the few classes of molecules for selective bone targeting. Their binding to calcium cations within hydroxyapatite (HA) is a key physicochemical event that takes place on the bone surface. It is the starting point for a cascade of biochemical reactions and cellular effects that lead to the pharmacological activity of BPs. The phenomenon has been known for years, yet its physicochemical nature is still not fully understood. In particular, the adsorption/release processes and structure–function relationships of BPs remain to be clarified. These are elementary, yet crucial factors, which should influence the design and development of new delivery tools or drugs with improved characteristics. This review summarizes the current understanding of the chemical interactions between clinically used BPs and bone mineral, starting from basic Ca2+coordination chemistry through to interactions with hydroxyapatite, nanocrystalline apatites, and natural bone mineral.
The effect of cell density, proximity, and time on the cytotoxicity of magnesium and galvanically coupled magnesium–titanium particles in vitro
Authors: Kim Jua , Gilbert Jeremy L. 
Published: January 2018

AbstractMagnesium (Mg) and galvanically coupled magnesium–titanium (Mg–Ti) particles in vitro have been reported previously to kill cells in a dosage‐dependent manner. Mg–Ti particles kill cells more effectively than Mg alone, due to the galvanic effect of Mg and Ti. This study further investigated the in vitro cytotoxicity of Mg and Mg–Ti in terms of particle concentration, cell density, time, and proximity. Cell density has an effect on cell viability only at low particle concentrations (below 250 µg/mL), where cell viability dropped only for lower cell densities (5000–10,000 cells/cm2) and not for higher cell densities (20,000–30,000 cells/cm2), showing that the particles cannot kill if there are more cells present. Cytotoxicity of Mg and Mg–Ti particles is quick and temporary, where the particles kill cells only during particle corrosion (first 24 h). Depending on the percentage of surviving cells, particle concentrations, and ongoing corrosion activity, the remaining live cells either proliferated and recovered, or just remained viable and quiescent. The particle killing is also proximity‐dependent, where cell viability was significantly higher for cells far away from the particles (greater than ∼1 mm) compared to those close to the particles (less than ∼1 mm). Although the increase of pH does affect cell viability negatively, it is not the sole killing factor since cell viability is significantly dependent on particle type and proximity but not pH. Mg and Mg–Ti particles used in this study are large enough to prevent direct cell phagocytosis so that the cell killing effect may be attributed to solely electrochemical reactions. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1428–1439, 2018.
Technical implementations of light sheet microscopy
Authors: Elisa Zagato , Toon Brans , De Smedt Stefaan C. , Katrien Remaut , Kristiaan Neyts , Kevin Braeckmans 
Published: January 2018

AbstractFluorescence‐based microscopy is among the most successful methods in biological studies. It played a critical role in the visualization of subcellular structures and in the analysis of complex cellular processes, and it is nowadays commonly employed in genetic and drug screenings. Among the fluorescence‐based microscopy techniques, light sheet fluorescence microscopy (LSFM) has shown a quite interesting set of benefits. The technique combines the speed of epi‐fluorescence acquisition with the optical sectioning capability typical of confocal microscopes. Its unique configuration allows the excitation of only a thin plane of the sample, thus fast, high resolution imaging deep inside tissues is nowadays achievable. The low peak intensity with which the sample is illuminated diminishes phototoxic effects and decreases photobleaching of fluorophores, ensuring data collection for days with minimal adverse consequences on the sample. It is no surprise that LSFM applications have raised in just few years and the technique has been applied to study a wide variety of samples, from whole organism, to tissues, to cell clusters, and single cells. As a consequence, in recent years numerous set‐ups have been developed, each one optimized for the type of sample in use and the requirements of the question at hand. Hereby, we aim to review the most advanced LSFM implementations to assist new LSFM users in the choice of the LSFM set‐up that suits their needs best. We also focus on new commercial microscopes and “do‐it‐yourself” strategies; likewise we review recent designs that allow a swift integration of LSFM on existing microscopes.
Reaction Mechanisms and Kinetics of the Melt Transesterification of Bisphenol‐A and Diphenyl Carbonate
Authors: Bi Feng‐Lei , Xi Zhen‐Hao , Zhao Ling 
Published: January 2018

ABSTRACTThe catalyzed and uncatalyzed reaction mechanisms of the melt transesterification process of bisphenol‐A and diphenyl carbonate are proposed based on nucleophilic substitution at the carbonyl group of the reactants. The reaction paths and energy barriers of the melt transesterification reaction were predicted and identified via density functional theory (DFT) calculations. The calculations reveal that the different oligomers with only one repeating unit are formed through different thermal processes. The theoretical evaluation further indicates that the basic hydroxide catalysts can reduce the energy barrier for the transesterification reaction, which allows subsequent nucleophilic attack to easily occur. Furthermore, the reaction kinetics of transesterification using tetraethyl ammonium hydroxide as a catalyst were investigated experimentally over a temperature range of 155–175°C. The reaction rate constants and equilibrium constants were determined based on the functional group model, and the equilibrium constants decreased with increasing reaction temperature. A detailed molecular species model with a specific repeating unit (n = 3) was developed and applied to predict the change in the reactants, oligomers, and phenol, and the experimental data and model calculation agree quite well. The standard curves of the oligomer were reversely derived, which provide intuitive insight into the concentration change of each oligomer. Both the DFT calculations and experimental results indicate that the C1 oligomer is first formed, and some of which are then converted to other types or higher molecular weight oligomers.
Postagrogenic development of Retisols in the middle taiga subzone of European Russia (Komi Republic)
Authors: Dymov Alexey A. , Dubrovskiy Yuriy A. , Startsev Viktor V. 
Published: January 2018

AbstractReforestation on abandoned agricultural lands is widespread in the belt of boreal forests. We analyzed the morphological and physicochemical properties of a Plaggic Glossic Retisol (Siltic, Cutanic) site that had been abandoned either 7, 19, or 85 years ago, as well as a Glossic Stagnic Retisol (Siltic, Cutanic) as a control. Involvement of forest soils in agricultural use results in the degradation of organic horizons, which are not restored until many decades after the termination of active agricultural use. Arable soil horizons were preserved and were clearly identified 85 years after the land had been abandoned. The morphological features of the eluvial and subeluvial horizons were determined at all sites. Soils at sites that had been abandoned for 7 and 19 years showed lower acidity and higher base saturation compared to the background soil. Total carbon stocks were lower at the abandoned sites. The slow increase of carbon stocks after the soil had been abandoned is caused by C increase as in the organic as in the topsoil mineral horizons. Soils that had been abandoned for 7 and 19 years contained less water‐extractable forms of C and N than the control and 85‐year forest soils. Agricultural use leads to a reduction in C stocks of forest soils. The postagrogenic soil C sequestration rate was estimated to be 30–40 g·m−2·yr−1.
Beta diversity diminishes in a chronosequence of desertification in a desert steppe
Authors: Tang Zhuangsheng , An Hui , Zhu Guangyu , Shangguan Zhouping 
Published: January 2018

AbstractBiodiversity is a central and multifaceted concept of community ecology, but a major challenge remains in understanding the variation mechanisms of biodiversity. Two ecological phenomena are shown in beta diversity: (a) spatial species turnover in space and (b) nestedness‐resultant of assemblages. Using a field experiment focusing on a desert steppe ecosystem, we show that desertification influences those two components in divergent ways depending on whether a deterministic or stochastic process is driving community composition. Desertification was a major driver of local environmental heterogeneity, which also resulted in decreased soil nutrients and led to increased turnover in a heterogeneous environment; however, spatial turnover of species decreased with desertification intensify. Desertification decreases resource availability, which causes species loss and reduced total beta diversity. Those desertification effects, therefore, had a homogenizing effect on the community. However, stochastic processes cannot be disregarded as a factor in community composition determination. Overall, these results indicated that the study of desertification effects on beta diversity would add our knowledge of the deterministic and stochastic processes that create and maintain biodiversity. This is crucial to assess the relative importance between stochastic processes and deterministic processes.
CEST‐Dixon for human breast lesion characterization at 3 T: A preliminary study
Authors: Zhang Shu , Seiler Stephen , Wang Xinzeng , Madhuranthakam Ananth J. , Keupp Jochen , Knippa Emily E. , Lenkinski Robert E. , Vinogradov Elena 
Published: January 2018

PurposeChemical exchange saturation transfer (CEST) MRI for breast lesion characterization is promising. However, artifacts are prone to develop in breast CEST imaging as a result of strong lipid signals. The aims of the study are (i) to develop and validate the CEST‐Dixon imaging sequence for simultaneous water‐fat separation and B0 mapping; and (ii) use the CEST‐Dixon method to characterize suspicious lesions in patients undergoing percutaneous biopsy.MethodsThe gradient‐echo multi‐echo Dixon acquisition is used to create fat‐free CEST and B0 maps. The sequence has been validated in phantoms and in vivo. Five healthy volunteers and 10 patients were scanned to compare the CEST contrast in three frequency ranges centered at 1, 2, and 3.5 ppm. The correlation between the CEST contrast and pathology markers (tumor type, estrogen receptor (ER) status, and Ki‐67) was also investigated by stratifying the patients into ER‐negative invasive ductal carcinoma (IDC) (more aggressive), ER‐positive IDC (less aggressive), and benign groups.ResultsThe CEST‐Dixon sequence shows homogenous fat removal in the water‐only images. The ER‐negative IDC tissues display a trend to higher CEST contrast in all three frequency ranges, whereas the ER‐positive IDC, benign, and normal tissues have lower CEST contrast. No significant differences were observed among the ER‐positive IDC, benign, and normal tissues. Of the three frequencies ranges, the CEST contrasts at 1 ppm are high in the ER‐negative IDC group, have the largest difference among the ER‐negative IDC and the other groups, and have the highest correlation with Ki‐67.ConclusionBreast CEST‐Dixon imaging shows potential to differentiate more aggressive from less aggressive cancers. Magn Reson Med 80:895–903, 2018. © 2018 International Society for Magnetic Resonance in Medicine.
Numerical evaluation of soft inter‐slab joint in concrete‐faced rockfill dam with dual mortar finite element method
Authors: Zhou Mozhen , Zhang Bingyin , Peng Chong 
Published: January 2018

SummaryRecently constructed concrete‐faced rockfill dams (CFRDs) often use soft inter‐slab joints to prevent axial compression‐induced extrusion damage in the concrete face. Due to the complexity of the multibody contact and the lack of information on the actual behavior of soft joints, it is highly challenging to numerically assess the effect of soft joints in CFRDs. In this paper, we present a numerical approach for the three‐dimensional modeling of CFRDs with hard and soft joints. A dual mortar finite element method with Lagrange multiplier is developed to treat the multibody contact in hard joints with impenetrability condition. The soft joint slab‐filler‐slab contact system is modeled using an equivalent contact interface approach, where the soft contact constraints are imposed using a perturbed Lagrange formulation. Through a series of laboratory tests, the mechanical behavior of soft joint is investigated. An extrusion model for the soft joint is presented and implemented in the dual mortar finite element method. The proposed numerical method is applied to the three‐dimensional analysis of Tianshengqiao‐1 CFRD. Despite the complex multibody contact and strong material and geometry nonlinearities in the CFRD, the proposed method is stable and capable of capturing salient characteristics of the CFRD. Numerical results show that in Tianshengqiao‐1, the employment of soft joints can effectively reduce the axial compression stress, thus greatly alleviating the risk of extrusion damage in the concrete face.
Simulation of the effect of an external GHz electric field on the potential energy profile of Ca2+ ions in the selectivity filter of the CaVAb channel
Authors: Adiban Jamal , Jamali Yousef , Rafii‐Tabar Hashem 
Published: January 2018

AbstractCaV channels are transmembrane proteins that mediate and regulate ion fluxes across cell membranes, and they are activated in response to action potentials to allow Ca2+ influx. Since ion channels are composed of charge or polar groups, an external alternating electric field may affect the ion‐selective membrane transport and the performance of the channel. In this article, we have investigated the effect of an external GHz electric field on the dynamics of calcium ions in the selectivity filter of the CaVAb channel. Molecular dynamics (MD) simulations and the potential of mean force (PMF) calculations were carried out, via the umbrella sampling method, to determine the free energy profile of Ca2+ ions in the CaVAb channels in presence and absence of an external field. Exposing CaVAb channel to 1, 2, 3, 4, and 5 GHz electric fields increases the depth of the potential energy well and this may result in an increase in the affinity and strength of Ca2+ ions to binding sites in the selectivity filter the channel. This increase of strength of Ca2+ ions binding in the selectivity filter may interrupt the mechanism of Ca2+ ion conduction, and leads to a reduction of Ca2+ ion permeation through the CaVAb channel.
Patterning Graphene Surfaces with Iron‐Oxide‐Embedded Mesoporous Polypyrrole and Derived N‐Doped Carbon of Tunable Pore Size
Authors: Zhu Shuyan , Tian Hao , Wang Nan , Chen Bin , Mai Yiyong , Feng Xinliang 
Published: January 2018

AbstractThis study develops a novel strategy, based on block copolymer self‐assembly in solution, for preparing two‐dimensional (2D) graphene‐based mesoporous nanohybrids with well‐defined large pores of tunable sizes, by employing polystyrene‐block‐poly(ethylene oxide) (PS‐b‐PEO) spherical micelles as the pore‐creating template. The resultant 2D nanohybrids possess a sandwich‐like structure with Fe2O3 nanoparticle‐embedded mesoporous polypyrrole (PPy) monolayers grown on both sides of reduced graphene oxide (rGO) nanosheets (denoted as mPPy‐Fe2O3@rGO). Serving as supercapacitor electrode materials, the 2D ternary nanohybrids exhibit controllable capacitive performance depending on the pore size, with high capacitance (up to 1006 F/g at 1 A/g), good rate performance (750 F/g at 20 A/g) and excellent cycling stability. Furthermore, the pyrolysis of mPPy‐Fe2O3@rGO at 800 °C yields 2D sandwich‐like mesoporous nitrogen‐doped carbon/Fe3O4/rGO (mNC‐Fe3O4@rGO). The mNC‐Fe3O4@rGO nanohybrids with a mean pore size of 12 nm show excellent electrocatalytic activity as an oxygen reduction reaction (ORR) catalyst with a four‐electron transfer nature, a high half‐wave‐potential of +0.84 V and a limiting current density of 5.7 mA/cm2, which are well comparable with those of the best commercial Pt/C catalyst. This study takes advantage of block copolymer self‐assembly for the synthesis of 2D multifunctional mesoporous nanohybrids, and helps to understand the control of their structures and electrochemical performance.