bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal‐Organic‐Framework‐Derived Co Nanoparticles Deposited on N‐Doped Bimodal Mesoporous Carbon Nanorods as Efficient Bifunctional Catalysts for Rechargeable Zinc−Air Batteries
Authors: Han Huijuan , Chao Shujun , Bai Zhengyu , Wang Xiaobing , Yang Xiaoli , Qiao Jinli , Chen Zhongwei , Yang Lin 
Published: January 2018

AbstractElectrically rechargeable zinc−air batteries (ZnABs) have received increasing attention as promising energy storage devices, owing to their high theoretical energy density and environmental friendliness. However, it remains a great challenge to develop highly efficient bifunctional catalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Herein, we design and prepare a highly active bifunctional catalyst for ZnABs by using a cobalt metal‐organic framework (Co‐MOF) as the precursor. The catalyst has a desirable nanostructure composed of cobalt nanoparticles deposited on N‐doped bimodal mesoporous carbon nanorods (Co@N‐CNR). This hybrid structure exhibits a higher catalytic activity (a maximum power density of 63 mW cm−2) and cycling stability compared to commercial Pt/C+Ir/C integrated in ZnABs. The high catalytic performance could be attributed to the unique nanostructure composed of Co@N‐CNR, which incorporates the advantageous features of cobalt nanoparticles, mesoporous materials, and N‐CNR towards OER and ORR. The reported advancement provides a new and efficient strategy for the development of rechargeable ZnABs.
Heterobimetallic Complexes for Theranostic Applications
Authors: Fernández‐Moreira Vanesa , Gimeno M. Concepción 
Published: January 2018

AbstractThe design of more efficient anticancer drugs requires a deeper understanding of their biodistribution and mechanism of action. Cell imaging agents could help to gain insight into biological processes and, consequently, the best strategy for attaining suitable scaffolds in which both biological and imaging properties are maximized. A new concept arises in this field that is the combination of two metal fragments as collaborative partners to provide the precise emissive properties to visualize the cell as well as the optimum cytotoxic activity to build more potent and selective chemotherapeutic agents.
Identification of the Minimal Glycotope of Streptococcus pneumoniae 7F Capsular Polysaccharide using Synthetic Oligosaccharides
Authors: Ménová Petra , Sella Mauro , Sellrie Katrin , Pereira Claney L. , Seeberger Peter H. 
Published: January 2018

AbstractStreptococcus pneumoniae causes life‐threatening diseases including meningitis, pneumonia and sepsis. Existing glycoconjugate vaccines based on purified capsular polysaccharides are widely used and help to prevent millions of deaths every year. Herein, the total syntheses of oligosaccharides resembling portions of the S. pneumoniae serotype 7F (ST7F) capsular polysaccharide repeating unit are reported. To define minimal glycan epitopes, glycan microarrays containing the synthetic oligosaccharides were used to screen human reference serum and revealed that both side chains of the ST7F play a key role in antigen recognition. The identification of protective minimal epitopes is vital to design efficient semi‐ and fully‐synthetic glycoconjugate vaccines.
Flexible all‐to‐all data redistribution methods for grid‐based particle codes
Authors: Hofmann Michael , Rünger Gudula 
Published: January 2018

SummaryThe article proposes a fine‐grained all‐to‐all communication operation that can implement flexible data redistribution patterns of irregular applications, such as particle codes. The flexibility is achieved by user‐defined distribution functions, which are used to specify how data elements are to be redistributed among parallel processes on a distributed memory platform. The usage is illustrated for a particle data redistribution step of a grid‐based particle code in which the destination processes for particles are calculated from the particle positions by a specific distribution function. Additionally, the fine‐grained all‐to‐all communication operation proposed allows the duplication and modification of data elements during the data redistribution. This functionality is useful for automatically creating ghost particles for the domain decomposition of the particle code during the particle data redistribution step. The interface of the fine‐grained all‐to‐all communication operation is described and several algorithms for implementing the operation on top of existing MPI operations are presented. Performance results on an IBM Blue Gene/Q platform demonstrate the performance of the communication operation proposed with synthetic benchmark data as well as with a parallel particle code.
Reaction Mechanism for Direct Cyclization of Linear C5, C6, and C7 Alkenes over H‐ITQ‐13 Zeolite Investigated Using Density Functional Theory
Authors: Ma Hong , Chen Yanyan , Wei Zhihong , Wang Sen , Qin Zhangfeng , Dong Mei , Li Junfen , Wang Jianguo , Fan Weibin 
Published: January 2018

AbstractAlthough dienes or trienes have been shown to be possible precursors for cyclization, direct cyclization of alkenes or alkoxides has not been systematically studied yet. Thus, the reaction mechanism of cyclization of linear alkenes over H‐ITQ‐13 was investigated here by density functional theory considering dispersive interactions (DFT‐D). The similar free energy of different linear alkoxides of the same carbon number suggests that they can co‐exist in the H‐ITQ‐13 intersection at 673.15 K during the methanol to olefins (MTO) process. The formation of linear alkenes by olefins methylation with methoxyl groups (ZOCH3), trimethyloxonium ions (TMO+), and methanol are kinetically more favorable than by dimerization of olefins. Linear alkoxides or alkenes prefer direct cyclization to cycloalkanes rather than hydride transfer to diene. This study provides new insight into the alkene cyclization and aromatization mechanisms in MTO process.
Preparation and Thermoelectric Properties of Zn‐Doped Sn‐Based Type‐VIII Single‐Crystalline Clathrate via a Grey Sn‐Flux Method
Authors: Shen Lanxian , Li Decong , Deng Shuping , Tang Yu , Chen Zhong , Liu Zuming , Yang Peizhi , Deng Shukang 
Published: January 2018

AbstractA single‐crystalline samples of Zn‐substituted type‐VIII clathrate Ba8Ga16Sn30 with n‐type carriers by α‐Sn flux method according to the formula Ba8Ga16ZnxSn30 (x = 0, 0.5, 1, and 1.5) is grown. It is found that as the amount of Zn increases from 0.025 to 0.155, the content of Ga decreases from 15.18 to 14.72, indicating Zn atoms preferentially replacing Ga. The carrier concentrations of obtained samples vary from 3.55 × 1019 to 5.53 × 1019 cm−3 as carrier mobility changes from 14.7 to 20.9 cm2 · V−1 · s−1 at room temperature. Meanwhile, the endothermic peak temperature for all samples is approximately 519 °C, which is slightly lower than that of the previous experimental reported. For all samples, their effective mass m*/m0 are lower than that prepared by β‐Sn, indicating that the band structure near the conduction band minima is affected. As a result, the sample with x = 1.5 obtains the higher power factor with the maximum value of 1.07 × 10−3 W m−1 K−2 at 568 K and the largest ZT value of 0.63 at 537 K.
Real‐Time Skin Lactic Acid Monitoring System for Assessment of Training Intensity
Authors: ENOMOTO KEIGO , SHIMIZU RYOSUKE , KUDO HIROYUKI 
Published: January 2018

SUMMARYA microfluidic system using electrochemical biosensor for continuous lactic acid (LA) monitoring at the skin's surface was fabricated and tested. The system consists of a micro flow‐cell for sampling LA at the skin's surface and a microfluidic LA biosensor based on a redox reaction of osmium wired horseradish peroxidase. Our system measures excreted LA by dissolving whole secretion in phosphate buffered saline (PBS), which was supplied into the microchannel as carrier flow. The measurement system was utilized in the real‐time monitoring of LA secretion during stationary bike exercises. Exercise intensities were regulated by heart rates (HRs) and the sampling device was attached on the right upper arm of the volunteer. During the exercise, PBS was circulated into the measurement system. As a result, change of LA levels correlated with the volunteer's physiological status was confirmed. Secretion of LA was estimated to be 4.50 μg/cm2/min when the intensity of exercise was high (HR: 160 bpm) and the signal decreased to the initial level after the exercise. This indicates that our system is suitable for not only the assessment of exercise intensity, but also useful in evaluation of metabolic activity.
State‐of‐Power Estimation of Li‐Ion Batteries Considering the Battery Surface Temperature
Authors: Liu Xintian , He Yao , Zeng Guojian , Zhang Jiangfeng , Zheng Xinxin 
Published: January 2018

AbstractThe state‐of‐power (SOP) of a Li‐ion battery (LIB) is an important evaluation index for safety control and energy recovery in electric vehicles. Major state estimation methods are only applicable to fixed room temperature at 20 °C, although the battery capacity and resistance vary dramatically with a change in battery surface temperature in the working process of the battery. This causes significant errors in state estimation if only room temperature is assumed. The inaccurate state may cause further excessive current at high or low temperatures to affect safety and life cycle of the battery. Therefore, a novel state estimation method applicable to various battery surface temperatures is developed here. This method uses capacity–temperature and resistance–temperature relationships from experimental data to more accurately predict battery capacity and resistance over the full temperature range. It then applies the extended Kalman filter (EKF) technique to estimate the state‐of‐charge, and a method of constrained multi‐parameter algorithm (CMPA) to estimate the SOP of LIBs. Simulation and experimental results show that the proposed method can obtain accurate SOP results at different temperatures.
Modeling spatially correlated spectral accelerations at multiple periods using principal component analysis and geostatistics
Authors: Markhvida Maryia , Ceferino Luis , Baker Jack W. 
Published: January 2018

SummaryRegional seismic risk assessments and quantification of portfolio losses often require simulation of spatially distributed ground motions at multiple intensity measures. For a given earthquake, distributed ground motions are characterized by spatial correlation and correlation between different intensity measures, known as cross‐correlation. This study proposes a new spatial cross‐correlation model for within‐event spectral acceleration residuals that uses a combination of principal component analysis (PCA) and geostatistics. Records from 45 earthquakes are used to investigate earthquake‐to‐earthquake trends in application of PCA to spectral acceleration residuals. Based on the findings, PCA is used to determine coefficients that linearly transform cross‐correlated residuals to independent principal components. Nested semivariogram models are then fit to empirical semivariograms to quantify the spatial correlation of principal components. The resultant PCA spatial cross‐correlation model is shown to be accurate and computationally efficient. A step‐by‐step procedure and an example are presented to illustrate the use of the predictive model for rapid simulation of spatially cross‐correlated spectral accelerations at multiple periods.
Anxiolytic‐like effects of essential oil from Thymus vulgaris was increased during stress
Authors: Satou Tadaaki , Hayakawa Mako , Goto Yumi , Masuo Yoshinori , Koike Kazuo 
Published: January 2018

AbstractThere is known to be a close relationship among anxiety, fatigue and stress. Here, we studied the anxiolytic‐like effects of essential oil from Thymus vulgaris (EOT), while focusing on the relationship with stress. Male ICR mice inhaled (i.h.) EOT for 90 min. Mice were placed under three different conditions; isolated, intraperitoneal (i.p.) administration of saline or polyinosinic‐polycytidylic acid (poly I:C). EOT did not show any significant anxiolytic‐like effects in isolated mice. On the other hand, in brain fatigue model mice by poly I:C, EOT showed significant anxiolytic‐like effects. EOT increased the absolute value in the elevated plus maze (EPM) tests in the brain fatigue model mice, while linalool and terpinen‐4‐ol in the brain with poly I:C were elevated when compared with isolated mice. Augmented concentrations of these components in the brain were also observed in mice with saline, i.p. These results suggest that the amount of volatile compounds transferred to the brain increased due to stress or inflammation. In the future, further investigation concerning the relationship between the blood brain barrier (BBB) and respiration is required.
New Insights into the Application of Lithium‐Ion Battery Materials: Selective Extraction of Lithium from Brines via a Rocking‐Chair Lithium‐Ion Battery System
Authors: He Lihua , Xu Wenhua , Song Yunfeng , Luo Yunze , Liu Xuheng , Zhao Zhongwei 
Published: January 2018

AbstractLithium extraction from high Mg/Li ratio brine is a key technical problem in the world. Based on the principle of rocking‐chair lithium‐ion batteries, cathode material LiFePO4 is applied to extract lithium from brine, and a novel lithium‐ion battery system of LiFePO4 | NaCl solution | anion‐exchange membrane | brine | FePO4 is constructed. In this method, Li+ is selectively absorbed from the brine by FePO4 (Li+ + e + FePO4 = LiFePO4); meanwhile, Li+ is desorbed from LiFePO4 (LiFePO4 − e = Li+ + FePO4) and enriched efficiently. To treat a raw brine solution, the Mg/Li ratio decreases from the initial 134.4 in the brine to 1.2 in the obtained anolyte and 83% lithium is extracted. For the treatment of an old brine solution, the Mg/Li ratio decreases from the initial 48.4 in the brine to 0.5 and the concentration of lithium in the anolyte is accumulated about six times (from the initial 0.51 g L−1 in the brine to 3.2 g L−1 in the anolyte), with the absorption capacity of about 25 mg (Li) g (LiFePO4)−1. Additionally, it displays a great perspective on the application in light of its high selectively, good cycling performance, effective lithium enrichment, environmental friendliness, low cost, and avoidance of poisonous organic reagents and harmful acid or oxidant.
Circular RNA hsa_circ_0000567 can be used as a promising diagnostic biomarker for human colorectal cancer
Authors: Wang Jianjun , Li Xiaomin , Lu Linming , He Lei , Hu Haoran , Xu Zengxiang 
Published: January 2018

BackgroundRecent studies have revealed that circular RNAs are involved in the biological process of some kinds of human cancers. However, little is known about their diagnostic values and functions in colorectal cancer (CRC).MethodsThe expression levels of hsa_circ_0000567 in 102 paired CRC tissues and adjacent noncancerous tissues, 5 CRC cell lines, and a normal colorectal epithelial cell line were detected by quantitative real‐time polymerase chain reaction (qRT‐PCR). The correlations between hsa_circ_0000567 expression levels and the clinicopathological factors of patients with CRC were analyzed. Furthermore, the loss‐of‐function assay was performed to investigate the functions of hsa_circ_0000567 in vitro. Finally, a receiver operating characteristic (ROC) curve was established to evaluate the diagnostic value of hsa_circ_0000567.ResultsHsa_circ_0000567 expression was significantly downregulated in CRC tissues and CRC cell lines. In addition, the decreased hsa_circ_0000567 expression in CRC was negatively correlated with tumor size (P = .011), lymph metastasis (P = .003), distal metastasis (P < .0001), and tumor–node–metastasis (TNM) stage (P = .003) in CRC. Moreover, knockdown of hsa_circ_0000567 promoted CRC cells proliferation and migration in vitro. Importantly, the area under the ROC curve (AUC) was 0.8653, which indicates hsa_circ_0000567 can serve as a diagnostic biomarker.ConclusionHsa_circ_0000567 may be a novel suppressor and a potential diagnosis biomarker in CRC.
Determination of vitamins K1, MK‐4, and MK‐7 in human serum of postmenopausal women by HPLC with fluorescence detection
Authors: Klapkova Eva , Cepova Jana , Dunovska Katerina , Prusa Richard 
Published: January 2018

BackgroundNew high‐performance liquid chromatography (HPLC) method was developed for the determination of vitamin K1 and two forms of vitamin K2 (MK‐4 and MK‐7) in human serum, and the levels of vitamin K were determined in 350 samples of postmenopausal women.MethodsVitamin K was determined by HPLC with fluorescence detection after postcolumn zinc reduction. The detection was performed at 246 nm (excitation) and 430 nm (emission). The internal standard and 2 mL of ethanol were added to 500 μL of serum. The mixture was extracted with 4 mL of hexane, and solid phase extraction was then used.ResultsThe HLPC method was fully validated. The intra‐ and interday accuracy and precision were evaluated on two QC samples by multiple analysis, and CV were less than 10%. The limit of quantification for MK‐4 was found at 0.04 ng/mL, for K1 0.03 ng/mL, and for MK‐7 0.03 ng/mL. The mean recoveries of the corresponding compounds were 98%‐110%. Serum levels of MK‐4, K1, and MK‐7 in postmenopausal women with osteoporosis were 0.890 ± 0.291 ng/mL, 0.433 ± 0.394 ng/mL, and 1.002 ± 1.020 ng/mL, respectively (mean ± SD). Serum levels of MK‐4, K1, and MK‐7 in postmenopausal women without osteoporosis were 0.825 ± 0.266 ng/mL, 0.493 ± 0.399 ng/mL, and 1.186 ± 1.076 ng/mL, respectively (mean ± SD).ConclusionNew HPLC method for the determination of vitamins K1, MK‐4, and MK‐7 in serum was evaluated and validated. This method is highly specific and sensitive with the low limit of quantification.
The politics of tourism statistics
Authors: Pratt Stephen , Tolkach Denis 
Published: January 2018

AbstractTourism statistics are important for policymakers to make prudent decisions and for researchers to conduct rigorous research. However, statistics are inherently political. This article highlights three areas where tourism statistics appear misleading, serving industry and government interests. First, United Nations World Tourism Organization's interpretation of national sovereignty such that domestic tourism arrivals are counted as international tourism arrivals. Second, United Nations World Tourism Organization's use of terminology with respect to international tourists and international trips, using both terms interchangeably. Third, anomalies in tourism statistics reported by various governments and international organizations. More critical analysis needs to be undertaken when reporting data. Researchers should use official statistics with caution.
Increased soil methane emissions and methanogenesis in oil contaminated areas
Authors: Yang Juejie , Li Guanghe , Qian Yi , Zhang Fang 
Published: January 2018

AbstractCrude oil exploration and related activities cause severe soil contamination and land degradation. However, how soil CH4 and CO2 fluxes respond to oil contamination is poorly understood. To address this question, we conducted in situ investigation of CH4 and CO2 emissions in the Shengli Oilfield, China. CH4 emissions from contaminated soils were 60–1,800 μg·m−2·hr−1, much higher than those from uncontaminated soils (29–33 μg·m−2·hr−1). CO2 fluxes of 2–78 mg·m−2·hr−1 were lower from contaminated soils compared with uncontaminated controls (78–104 mg·m−2·hr−1). The variance of CH4 and CO2 fluxes could be explained to 78.0% by soil properties and oil well age (p < .001) as suggested by the redundancy analysis and the variance partitioning analysis. On the basis of the Illumina MiSeq sequencing of the archaeal 16S rRNA gene, the relative abundance of methanogens over archaea increased by 8 times in contaminated soils compared with that in the uncontaminated soils, suggesting enhanced methanogenesis processes. The proportion of hydrogenotrophic methanogens over the total methanogens increased from 35% in the uncontaminated soil to 43% in the contaminated soils, consistent with the higher apparent fractionation factor (αC) in the stable isotope analysis. Both microbial and isotopic results suggested that the hydrogenotrophic methanogenesis relatively enhanced with the oil contamination, with less dominance of the acetoclastic methanogenesis. The dramatically increased CH4 emissions under oil contamination call for great attention as a potentially important anthropogenic source of CH4 in the atmosphere.
Comparative Study of Distribution of Active Sites According to Their Stereospecificity in Propylene Polymerization over the Traditional TiCl3 and Supported Titanium–Magnesium Catalysts with Different Composition
Authors: Nikolaeva Marina , Matsko Mikhail , Zakharov Vladimir 
Published: January 2018

AbstractThe preparative‐temperature rising elution fractionation method is used to obtain comparative data on contents of fractions with different microtacticities for polypropylene (PP) samples prepared using three catalytic systems: the traditional Ziegler–Natta (Z–N) catalyst δ‐TiCl3 and two types of supported titanium–magnesium catalysts: the “donor‐free” TiCl4/MgCl2 catalyst and TiCl4/MgCl2·nDBP catalyst (DBP – dibutylphthalate used as an internal donor) at polymerization with the same cocatalyst (AlEt3) in the absence and presence of an external donor (propyltrimetoxy silane). The separated individual PP fractions are also studied by gel permeation chromatography (molecular weight and molecular weight distribution) and differential scanning calorimetry. The results demonstrate general regularities and differences in the formation of active sites having different isospecificities for the traditional TiCl3‐based Z–N catalyst and highly active supported titanium–magnesium catalysts.
Borate‐Mediated Stereo‐ and Topo‐Selective Methylation of 1,4‐β‐Glucomannan
Authors: Zhang Qimeng , Mischnick Petra 
Published: January 2018

AbstractKonjak glucomannan (KGM) is methylated with NaOH/MeI in water in the presence of borate and as a reference without this additive. With increasing equiv. of borate increasing suppression of 2‐ and 3‐O‐methylation of mannosyl residues (M) is observed, while glucosyl units (G) are mainly affected at O‐6, but to much lower extent. Raising the temperature and/or addition of acetone as a co‐solvent enhance reactivity, but at the cost of M/G regioselectivity. O‐Methyl konjac glucomannans (M‐KGM) with an average degree of substitution (DS) up to 0.8 and a DS ratio for G and M up to 2 are obtained. From liquid chromatrography–electrospray ionization–mass spectrometry (LC‐ESI‐MS) of the oligosaccharides obtained from M‐KGM, it is concluded that borate‐mediated transient protection might also depend on the location of M within KGM. Comparison with random and block models supports random distribution of M and G in KGM. Thermogravimetric analysis shows higher decomposition temperature of M‐KGMs with increasing DS.
Significant Improvement on Polybenzoxazine Toughness Achieved by Amine/Benzoxazine Copolymerization‐Induced Phase Separation
Authors: Zhao Yang , Xu Yazhen , Xu Qingbo , Fu Feiya , Zhang Yanyan , Endo Takeshi , Liu Xiangdong 
Published: January 2018

AbstractTwo commercially available amines, octanediamine (ODM) and m‐xylylenediamine (MXDM), are chosen for tough polybenzoxazine resin due to their controllable capability to cause phase separation during the copolymerization with benzoxazine monomers. The toughening behavior and phase separation of the cured resins are investigated using tensile tests and analyses of dynamic mechanical analysis (DMA), scanning electron microscope, and thermal gravimetry–gas chromatography/mass spectroscopy. The resulting networks show remarkable toughness without obvious degradation in thermomechanical performance. Especially, when ODM/MXDM molar ratio is 1:1, an elongation rate of 10.55% and a breaking strength of 82.67 Mpa, which are 86% and 128% higher than that of the neat benzoxazine resin, respectively, are achieved. These findings open a new way to improve toughness of brittle polybenzoxazine resins.