bluuebunny/crossref_metadata_2025 huggingface dataset:
Nearly massless Dirac fermions hosted by Sb square net in BaMnSb2
Authors: Liu Jinyu , Hu Jin , Cao Huibo , Zhu Yanglin , Chuang Alyssa , Graf D. , Adams D. J. , Radmanesh S. M. A. , Spinu L. , Chiorescu I. , Mao Zhiqiang
Published: July 2016

Layered compounds AMnBi2 (A = Ca, Sr, Ba, or rare earth element) have been established as Dirac materials. Dirac electrons generated by the two-dimensional (2D) Bi square net in these materials are normally massive due to the presence of a spin-orbital coupling (SOC) induced gap at Dirac nodes. Here we report that the Sb square net in an isostructural compound BaMnSb2 can host nearly massless Dirac fermions. We observed strong Shubnikov-de Haas (SdH) oscillations in this material. From the analyses of the SdH oscillations, we find key signatures of Dirac fermions, including light effective mass (~0.052m0; m0, mass of free electron), high quantum mobility (1280 cm2V−1S−1) and a π Berry phase accumulated along cyclotron orbit. Compared with AMnBi2, BaMnSb2 also exhibits much more significant quasi two-dimensional (2D) electronic structure, with the out-of-plane transport showing nonmetallic conduction below 120 K and the ratio of the out-of-plane and in-plane resistivity reaching ~670. Additionally, BaMnSb2 also exhibits a G-type antiferromagnetic order below 283 K. The combination of nearly massless Dirac fermions on quasi-2D planes with a magnetic order makes BaMnSb2 an intriguing platform for seeking novel exotic phenomena of massless Dirac electrons.
Enhanced photoelectrochemical and photocatalytic behaviors of MFe2O4 (M = Ni, Co, Zn and Sr) modified TiO2 nanorod arrays
Authors: Gao Xin , Liu Xiangxuan , Zhu Zuoming , Wang Xuanjun , Xie Zheng
Published: July 2016

Modified TiO2 nanomaterials are considered to be promising in energy conversion and ferrites modification may be one of the most efficient modifications. In this research, various ferrites, incorporated with various cations (MFe2O4, M = Ni, Co, Zn and Sr), are utilized to modify the well aligned TiO2 nanorod arrays (NRAs), which is synthesized by hydrothermal method. It is found that all MFe2O4/TiO2 NRAs show obvious red shift into the visible light region compared with the TiO2 NRAs. In particular, NiFe2O4 modification is demonstrated to be the best way to enhance the photoelectrochemical and photocatalytic activity of TiO2 NRAs. Furthermore, the separation and transfer of charge carriers after MFe2O4 modification are clarified by electrochemical impedance spectroscopy measurements. Finally, the underlying mechanism accounting for the enhanced photocatalytic activity of MFe2O4/TiO2 NRAs is proposed. Through comparison among different transition metals modified TiO2 with the same synthesis process and under the same evaluating condition, this work may provide new insight in designing modified TiO2 nanomaterials as visible light active photocatalysts.
Magnetic Resonance Imaging of Phosphocreatine and Determination of BOLD Kinetics in Lower Extremity Muscles using a Dual-Frequency Coil Array
Authors: Brown Ryan , Khegai Oleksandr , Parasoglou Prodromos
Published: July 2016

Magnetic resonance imaging (MRI) provides the unique ability to study metabolic and microvasculature functions in skeletal muscle using phosphorus and proton measurements. However, the low sensitivity of these techniques can make it difficult to capture dynamic muscle activity due to the temporal resolution required for kinetic measurements during and after exercise tasks. Here, we report the design of a dual-nuclei coil array that enables proton and phosphorus MRI of the human lower extremities with high spatial and temporal resolution. We developed an array with whole-volume coverage of the calf and a phosphorus signal-to-noise ratio of more than double that of a birdcage coil in the gastrocnemius muscles. This enabled the local assessment of phosphocreatine recovery kinetics following a plantar flexion exercise using an efficient sampling scheme with a 6 s temporal resolution. The integrated proton array demonstrated image quality approximately equal to that of a clinical state-of-the-art knee coil, which enabled fat quantification and dynamic blood oxygen level-dependent measurements that reflect microvasculature function. The developed array and time-efficient pulse sequences were combined to create a localized assessment of calf metabolism using phosphorus measurements and vasculature function using proton measurements, which could provide new insights into muscle function.
Molecular developmental mechanism in polypterid fish provides insight into the origin of vertebrate lungs
Authors: Tatsumi Norifumi , Kobayashi Ritsuko , Yano Tohru , Noda Masatsugu , Fujimura Koji , Okada Norihiro , Okabe Masataka
Published: July 2016

The lung is an important organ for air breathing in tetrapods and originated well before the terrestrialization of vertebrates. Therefore, to better understand lung evolution, we investigated lung development in the extant basal actinopterygian fish Senegal bichir (Polypterus senegalus). First, we histologically confirmed that lung development in this species is very similar to that of tetrapods. We also found that the mesenchymal expression patterns of three genes that are known to play important roles in early lung development in tetrapods (Fgf10, Tbx4 and Tbx5) were quite similar to those of tetrapods. Moreover, we found a Tbx4 core lung mesenchyme-specific enhancer (C-LME) in the genomes of bichir and coelacanth (Latimeria chalumnae) and experimentally confirmed that these were functional in tetrapods. These findings provide the first molecular evidence that the developmental program for lung was already established in the common ancestor of actinopterygians and sarcopterygians.
Consecutive Reaction to Construct Hierarchical Nanocrystalline CuS “Branch” with Tunable Catalysis Properties
Authors: Zhang Xiangdan , Yang Feifei , Cui Shizhong , Wei Wutao , Chen Weihua , Mi Liwei
Published: July 2016

New CuS nanocrystals with a 3D hierarchical branched structure are successfully synthesized through in situ consecutive reaction method with copper foam as template. The formation mechanism of the 3D hierarchical branched structure obtained from the secondary reaction is investigated by adjusting the reaction time. The morphology of CuS nanosheet arrays with the 3D hierarchical branched structure is changed through Cu2+ exchange. In this method, the copper foam reacted completely, and the as-synthesized CuS@Cu9S5 nanocrystals are firmly grown on the surface of the 3D framework. This tunable morphology significantly influence the physical and chemical properties, particularly catalytic performance, of the materials. The as-obtained material of Cu@CuS-2 with the 3D hierarchical branched structure as catalyst for methylene blue degradation exhibits good catalytic performance than that of the material of Cu@CuS with 2D nanosheets in dark environment. Furthermore, the cation exchange between Cu and Cu2+ indicates that Cu2+ in wastewater could be absorbed by Cu@CuS-2 with the 3D hierarchical branched structure. The exchanged resultant of CuS@Cu9S5 retains its capability to degrade organic dyes. This in situ consecutive reaction method may have a significant impact on controlling the crystal growth direction of inorganic material.
Local noise in a diffusive conductor
Authors: Tikhonov E. S. , Shovkun D. V. , Ercolani D. , Rossella F. , Rocci M. , Sorba L. , Roddaro S. , Khrapai V. S.
Published: July 2016

The control and measurement of local non-equilibrium configurations is of utmost importance in applications on energy harvesting, thermoelectrics and heat management in nano-electronics. This challenging task can be achieved with the help of various local probes, prominent examples including superconducting or quantum dot based tunnel junctions, classical and quantum resistors, and Raman thermography. Beyond time-averaged properties, valuable information can also be gained from spontaneous fluctuations of current (noise). From these perspective, however, a fundamental constraint is set by current conservation, which makes noise a characteristic of the whole conductor, rather than some part of it. Here we demonstrate how to remove this obstacle and pick up a local noise temperature of a current biased diffusive conductor with the help of a miniature noise probe. This approach is virtually noninvasive for the electronic energy distributions and extends primary local measurements towards strongly non-equilibrium regimes.
A Decentralized Approach to the Formulation of Hypotheses: A Hierarchical Structural Model for a Prion Self-Assembled System
Authors: Wang Mingyang , Zhang Feifei , Song Chao , Shi Pengfei , Zhu Jin
Published: July 2016

Innovation in hypotheses is a key transformative driver for scientific development. The conventional centralized hypothesis formulation approach, where a dominant hypothesis is typically derived from a primary phenomenon, can, inevitably, impose restriction on the range of conceivable experiments and legitimate hypotheses, and ultimately impede understanding of the system of interest. We report herein the proposal of a decentralized approach for the formulation of hypotheses, through initial preconception-free phenomenon accumulation and subsequent reticular logical reasoning processes. The two-step approach can provide an unbiased, panoramic view of the system and as such should enable the generation of a set of more coherent and therefore plausible hypotheses. As a proof-of-concept demonstration of the utility of this open-ended approach, a hierarchical model has been developed for a prion self-assembled system, allowing insight into hitherto elusive static and dynamic features associated with this intriguing structure.
Citrobacter freundii carrying blaKPC-2 and blaNDM-1: characterization by whole genome sequencing
Authors: Wu Wenjing , Espedido Björn , Feng Yu , Zong Zhiyong
Published: July 2016

A carbapenem-resistant Citrobacter freundii strain WCHCF65 was recovered from hospital sewage and was characterized by genome sequencing and conjugation experiments. The strain carried nine genes encoding β-lactamases including two carbapenemase genes, blaNDM-1 and blaKPC-2. blaNDM-1 was carried on an IncX3 plasmid, which was identical to a plasmid found in a local Escherichia coli, suggesting interspecies horizontal transfer. blaKPC-2 was bracketed by two copies of insertion sequence ISKpn19, which could form a composite transposon with the potential to mobilize blaKPC-2, on a new type of plasmid. The coexistence of blaNDM-1 and blaKPC-2 conferred higher levels of resistance to carbapenems compared with blaNDM-1 or blaKPC-2 alone. The coexistence of these carbapenemase genes, on two different plasmids, in one strain may allow new genetic platforms to be generated to mediate their spread.
Polymorphisms in TCF7L2 gene are associated with gestational diabetes mellitus in Chinese Han population
Authors: Ye Dan , Fei Yang , Ling Qi , Xu Weiwei , Zhang Zhe , Shu Jing , Li Chengjiang , Dong Fengqin
Published: July 2016

This study aimed to investigate the possible association between diabetes susceptibility gene transcription factor 7-like 2 (TCF7L2) and gestational diabetes mellitus (GDM) in a Chinese Han population. A total of 556 GDM patients and 500 Non-GDM were included. Eighteen single nucleotide polymorphisms (SNPs) were evaluated. Fifteen tag SNPs were selected from HapMap CHB database with a minor allele frequency of >0.2 and r2of >0.8. Three additional SNPs were also chosen because these SNPs are associated with type 2 diabetes in East Asians.TCF7L2rs290487, rs6585194, and rs7094463 polymorphisms were found to be significantly associated with GDM. In multivariate analysis, rs290487 genetic variation (OR = 2.686 per each C allele,P = 0.002), pre-BMI > 24 kg/m2(OR = 1.592,P = 0.018), age > 25 years (OR = 1.780,P = 0.012) and LDL-C > 3.6 mmol/L (OR = 2.034, P = 0.009) were identified as independent risk factors of GDM, rs7094463 genetic variation (OR = 0.429 per each G allele,P = 0.005) was identified as independent protect factor of GDM. This finding suggests thatTCF7L2rs290487, and rs7094463 were a potential clinical value for the prediction of GDM.
Facultative parthenogenesis in the Ryukyu drywood termite Neotermes koshunensis
Authors: Kobayashi Kazuya , Miyaguni Yasushi
Published: July 2016

Parthenogenesis is a relatively rare reproductive mode in nature compared to sex. In social insects, the evolution of parthenogenesis has a notable impact on their life histories. Some termites with parthenogenetic ability produce numerous non-dispersing supplementary queens asexually, whereas other castes are produced via sexual reproduction. This asexual queen succession (AQS) system is adaptive because hundreds of the asexual queens improve the reproductive potential of the colony and maintain the genetic diversity within the colony. However, the evolutionary process of the AQS system remains unclear because parthenogenetic species without this system are unknown. Here, we report facultative parthenogenesis in the drywood termiteNeotermes koshunensis. Although the eggs produced by females isolated from males hatched, the hatching rate of those eggs was lower than that of the eggs produced by females kept with males. These parthenogenetic offspring inherited only the maternal alleles and showed high homozygosity, which indicates that the mechanism of ploidy restoration is terminal fusion. A previous study showed that most colonies of this species have a single queen or orphan; thus, the AQS system has not evolved despite their parthenogenetic ability. Further investigations ofN. koshunensiswill reveal how parthenogenesis evolved and its role in the insect societies.
Exome-based Variant Detection in Core Promoters
Authors: Kim Yeong C. , Cui Jian , Luo Jiangtao , Xiao Fengxia , Downs Bradley , Wang San Ming
Published: July 2016

Core promoter controls the initiation of transcription. Core promoter sequence change can disrupt transcriptional regulation, lead to impairment of gene expression and ultimately diseases. Therefore, comprehensive characterization of core promoters is essential to understand normal and abnormal gene expression in biomedical studies. Here we report the development of EVDC (Exome-based Variant Detection in Core promoters) method for genome-scale analysis of core-promoter sequence variation. This method is based on the fact that exome sequences contain the sequences not only from coding exons but also from non-coding region including core promoters generated by random fragmentation in exome sequencing process. Using exome data from three cell types of CD4+ T cells, CD19+ B cells and neutrophils of a single individual, we characterized the features of core promoter-mapped exome sequences, and analysed core-promoter variation in this individual genome. We also compared the core promoters between YRI (Yoruba in Ibadan, Nigeria) and the CEU (Utah residents of European decedent) populations using the exome data generated by the 1000 Genome project, and observed much higher variation in YRI population than in CEU population. Our study demonstrates that the EVDC method provides a simple but powerful means for genome-wile de novo characterization of core promoter sequence variation.
Bimodal behaviour of charge carriers in graphene induced by electric double layer
Authors: Tsai Sing-Jyun , Yang Ruey-Jen
Published: July 2016

A theoretical investigation is performed into the electronic properties of graphene in the presence of liquid as a function of the contact area ratio. It is shown that the electric double layer (EDL) formed at the interface of the graphene and the liquid causes an overlap of the conduction bands and valance bands and increases the density of state (DOS) at the Fermi energy (EF). In other words, a greater number of charge carriers are induced for transport and the graphene changes from a semiconductor to a semimetal. In addition, it is shown that the dependence of the DOS at EF on the contact area ratio has a bimodal distribution which responses to the experimental observation, a pinnacle curve. The maximum number of induced carriers is expected to occur at contact area ratios of 40% and 60%. In general, the present results indicate that modulating the EDL provides an effective means of tuning the electronic properties of graphene in the presence of liquid.
1H-NMR fingerprinting of brown rice syrup as a common adulterant in honey
Authors: Musharraf Syed Ghulam , Ambreen Fatima Syeda , Siddiqui Amna Jabbar , Iqbal Choudhary M. , Atta-ur-Rahman Atta-ur-Rahman
Published: July 2016

Honey is often adulterated because of its high economic value and increasing consumption.
A magnetic ZrO2 based solid-phase extraction strategy for selective enrichment and profiling of glycosylated compounds in rice
Authors: Jiang Meng-Ying , Huang Yun-Qing , Chu Jie-Mei , Zhu Quan-Fei , Ding Jun , Yuan Bi-Feng , Feng Yu-Qi
Published: July 2016

A magnetic ZrO2-based solid-phase extraction strategy combined with LC-HRMS for selective enrichment and profiling of glycosylated small molecules in rice.
Total removal of intact blood plasma proteins deposited on surface-grafted polymer brushes
Authors: Riedel T. , Májek P. , Riedelová-Reicheltová Z. , Vorobii M. , Houska M. , Rodriguez-Emmenegger C.
Published: July 2016

Buffers/solutions suitable for total desorption of adsorbed proteins on low fouling polymer brushes are presented, enabling analysis not only by MS, but also a plethora of other state-of-the-art proteomics methods.
Capturing the transient species at the electrode–electrolyte interface by in situ dynamic molecular imaging
Authors: Yu Jiachao , Zhou Yufan , Hua Xin , Liu Songqin , Zhu Zihua , Yu Xiao-Ying
Published: July 2016

In situ imaging mass spectrometry captured transient species at the solid electrode and electrolyte interface, revealing more complex interfacial reactions.
Direct NHC-catalysed redox amidation using CO2 for traceless masking of amine nucleophiles
Authors: Davidson Robert W. M. , Fuchter Matthew J.
Published: July 2016

We report an amine masking strategy for N-heterocyclic carbene (NHC)-catalysed redox amidation that couples release of the free nucleophile to catalytic turnover, and in doing so, enables direct reaction of electron-rich amines.
Synthesis of 2,2′-biphenols through direct C(sp2)–H hydroxylation of [1,1′-biphenyl]-2-ols
Authors: Duan Shitao , Xu Yuanshuang , Zhang Xinying , Fan Xuesen
Published: July 2016

A novel synthesis of diversely substituted 2,2′-biphenols through Pd(ii)-catalyzed,tBuOOH-oxidized, and hydroxyl-directed C(sp2)–H hydroxylation of [1,1′-biphenyl]-2-ols has been developed.
Rapid screening of copper intermediates in Cu(i)-catalyzed azide–alkyne cycloaddition using a modified ICP-MS/MS platform
Authors: He Qian , Xing Zhi , Wei Chao , Fang Xiang , Zhang Sichun , Zhang Xinrong
Published: July 2016

Rapid screening of Cu+-intermediates by using 63Cu+ or 65Cu+ ions as catalysts in Cu(i)-catalyzed azide–alkyne cycloaddition was realized using an on-line modified ICP-MS/MS platform.
Realizing controllable graphene nucleation by regulating the competition of hydrogen and oxygen during chemical vapor deposition heating
Authors: Zhang Haoran , Zhang Yaqian , Zhang Yanhui , Chen Zhiying , Sui Yanping , Ge Xiaoming , Deng Rongxuan , Yu Guanghui , Jin Zhi , Liu Xinyu
Published: July 2016

Controllable graphene nucleation on a CuO/Cu substrate can be realised by adjusting the hydrogen introduction temperature.
A series of Keggin-based compounds constructed by conjugate ring-rich pyrazine and quinoxaline derivatives
Authors: Tian Aixiang , Tian Yan , Ning Yali , Hou Xue , Ni Huaiping , Ji Xuebin , Liu Guocheng , Ying Jun
Published: July 2016

Ligands L1 and L2 are utilized in POM chemistry for the first time. Different Keggin anions induce distinct 2D structures of compounds 1/2 and 3/4 in Ag–L1 and Ag–L2 systems, respectively. By adding AgI and CuI to the PMo12–L2 system different 3 and 5 were formed.
Direct carbon–carbon bond formation via reductive soft enolization: a syn-selective Mannich addition of α-iodo thioesters
Authors: Truong Ngoc , Sauer Scott J. , Seraphin-Hatcher Cyndie , Coltart Don M.
Published: July 2016

The β-amino carboxylic acid moiety is a key feature of numerous important biologically active compounds.
Fabrication of binary hybrid-filled layer-by-layer coatings on flexible polyurethane foams and studies on their flame-retardant and thermal properties
Authors: Pan Haifeng , Lu Yushi , Song Lei , Zhang Xiaotao , Hu Yuan
Published: July 2016

A binary hybrid-filled flame-retardant coating, consisting of graphene oxide (GO) and amino-terminated silica nanospheres (KH-550-SiO2), was fabricated onto a flexible polyurethane (FPU) foam using the layer-by-layer assembly method.
Phenolic content, antioxidant and enzyme inhibitory capacity of two Trametes species
Authors: Zengin Gokhan , Karanfil Abdullah , Uren Mehmet Cemil , Kocak Mehmet Sefa , Sarikurkcu Cengiz , Gungor Halil , Nancy Picot Carene Marie , Mahomoodally Mohamad Fawzi
Published: July 2016

The phenolic composition, antioxidant and enzyme inhibitory activities of two mushrooms (Trametes gibbosaandTrametes hirsuta) were characterised for the first time which proved to be potential candidates for new functional food formulations.
Photoelectrochemical properties of Ti-doped hematite nanosheet arrays decorated with CdS nanoparticles
Authors: Xie Xin , Li Kui , Zhang Wei-De
Published: July 2016

A photoanode comprised of vertically aligned Ti-doped hematite nanosheet arrays decorated with cadmium sulfide nanoparticles was fabricated. The Ti-Fe2O3/CdS electrode shows high photoelectrochemical response under visible light irradiation.
Colorimetric detection of Hg2+ based on inhibiting the peroxidase-like activity of DNA–Ag/Pt nanoclusters
Authors: Wu Liang-Liang , Wang Li-Ying , Xie Zheng-Jun , Xue Feng , Peng Chi-Fang
Published: July 2016

This paper reported that the peroxidase-like activity of DNA–Ag/Pt nanoclusters (NCs) can be inhibited selectively by Hg2+.
Synthesis of Ti3+ self-doped TiO2 nanocrystals based on Le Chatelier's principle and their application in solar light photocatalysis
Authors: Qiu Maoqin , Tian Yuan , Chen Zhangxian , Yang Zeheng , Li Wenming , Wang Kai , Wang Lei , Wang Kun , Zhang Weixin
Published: July 2016

Ti3+-doped TiO2 nanocrystals, synthesized based on Le Chatelier's principle, show a high degradation ratio of 99% towards MB under sun light.
RGD conjugated, Cy5.5 labeled polyamidoamine dendrimers for targeted near-infrared fluorescence imaging of esophageal squamous cell carcinoma
Authors: Li Qi , Gu Wei , Liu Kang , Xiao Ning , Zhang Juan , Shao Linlin , Li Lei , Zhang Shutian , Li Peng
Published: July 2016

The early detection of esophageal squamous cell carcinoma (ESCC), one of the most common human neoplasms, is of great importance in improving prognosis.
Insight into the short-term effect of titanium dioxide nanoparticles on active ammonia oxidizing microorganisms in a full-scale wastewater treatment plant: a DNA-stable isotope probing study
Authors: Gao Jing-Feng , Fan Xiao-Yan , Luo Xin , Pan Kai-Ling
Published: July 2016

Ammonia-oxidizing bacteria (AOB) and archaea (AOA) are two distinct ammonia-oxidizing microorganisms (AOMs) responsible for nitrification in wastewater treatment plants (WWTPs).
Chitosan-thiomer stabilized silver nano-composites for antimicrobial and antioxidant applications
Authors: Chauhan Kalpana , Sharma Rahul , Dharela Rohini , Chauhan Ghanshyam Singh , Singhal Rakesh Kumar
Published: July 2016

The present study involves a microwave assisted, greener synthesis of chitosan thiomer silver nanocomposites via an innocuous thiourea reagent for antimicrobial applications.
Facile biosurfactant assisted biocompatible α-Fe2O3 nanorods and nanospheres synthesis, magneto physicochemical characteristics and their enhanced biomolecules sensing ability
Authors: Sundar Sasikala , Mariappan Ramalakshmi , Min Kim , Piraman Shakkthivel
Published: July 2016

Tunable magnetic and electrocatalytic characteristics of α-Fe2O3 nanostructures were fabricated by tapping saponin induced anisotropic growth, demonstrated excellent electrocatalytic activity towards dopamine and uric acid with wider potential gap.
Tuning magnetoresistive and magnetocaloric properties via grain boundaries engineering in granular manganites
Authors: Mohamed Abd El-Moez A. , Mohamed Mohamed A. , Vega V. , Hernando B. , Ahmed A. M.
Published: July 2016

The effect of interface size on the relative cooling power and magnetoresistive properties of La0.7Ba0.3MnO3 compounds is investigated.
Size fractionation of graphene oxide sheets assisted by circular flow and their graphene aerogels with size-dependent adsorption
Authors: Zhang Shiyu , Li Yajun , Sun Jun , Wang Jianjun , Qin Chuanxiang , Dai Lixing
Published: July 2016

Crude GO sheets are easily separated into three size ranges, namely LGO, MGO and SGO, assisted by circular flow.
Re-evaluation of the N-terminal substitution and the D-residues of teixobactin
Authors: Abdel Monaim Shimaa A. H. , Jad Yahya E. , Acosta Gerardo A. , Naicker Tricia , Ramchuran Estelle J. , El-Faham Ayman , Govender Thavendran , Kruger Hendrik G. , de la Torre Beatriz G. , Albericio Fernando
Published: July 2016

Teixobactin is a head to side-chain cyclic depsipeptide with a guanidino based residue within the cycle, three d-amino acids in the tail, and a N-methylated terminal residue.
Atmospheric chemistry of bioaerosols: heterogeneous and multiphase reactions with atmospheric oxidants and other trace gases
Authors: Estillore Armando D. , Trueblood Jonathan V. , Grassian Vicki H.
Published: July 2016

Once airborne, biologically-derived aerosol particles are prone to reaction with various atmospheric oxidants such as OH, NO3, and O3.
Multiple effects of Bi doping in enhancing the thermoelectric properties of SnTe
Authors: Zhou Zhiwei , Yang Junyou , Jiang Qinghui , Luo Yubo , Zhang Dan , Ren Yangyang , He Xu , Xin Jiwu
Published: July 2016

We studied the effect of doping with Bi on the thermoelectric properties of SnTe-based materials.
The effects of donor : acceptor intermolecular mixing and acceptor crystallization on the composition ratio of blended, spin coated organic thin films
Authors: Weintraub Matthew T. , Xhakaj Enia , Austin Ashli , Szarko Jodi M.
Published: July 2016

Here we show evidence of the change in the final composition ratio of donor : acceptor blended films as a function of acceptor crystallization.
Evaluation of new color metrics: guidelines for developing narrow-band red phosphors for WLEDs
Authors: Oh Ji Hye , Eo Yun Jae , Yoon Hee Chang , Huh Young-Duk , Do Young Rag
Published: July 2016

In this review, we summarize the recent findings on novel narrow-band red phosphors, the improved color and visual energy properties of these phosphors, and their ability to improve the optical properties of corresponding warm white pc-WLED lightings.
Prestin and the good vibrations
Authors: Birke Anna Sofia , Javelle Arnaud
Published: July 2016

In a recent paper published in the Biochemical Journal, Lolli et al. presented evidence that the C-terminal STAS (sulfate transporter and anti-sigma factor antagonist) domain of the motor protein prestin possesses an anion-binding site. This discovery might shed light on an aspect of the function of this mysterious and fascinating protein that is crucial for the human hearing system.
SLL reduction of slot array antenna by artificial magnetic conductor side walls
Authors: Esmaeli S.H. , Sedighy S.H.
Published: July 2016

A new waveguide slot array antenna with two artificial magnetic conductor (AMC) side walls is proposed. The AMC layers reflect the wave with different phase delays through the waveguide side walls which compensate the requirement of slots offset and improve the antenna gain and sidelobe level (SLL). A five slots array antenna with AMC layers is designed and measured which shows 9 dB SLL reduction and 1.5 dB gain enhancement with compact size compared with the conventional Elliot one. These results clarify the ability and capability of the proposed design approach.
Low loss 100 GHz spacing Si arrayed‐waveguide grating using minimal terrace at slab–array interface
Authors: Okayama H. , Onawa Y. , Shimura D. , Takahashi H. , Yaegashi H. , Sasaki H.
Published: July 2016

Si wire arrayed‐waveguide grating is reported using local rib waveguide generating multimode interference at the array and slab waveguide interface. An 8ch device with 100 GHz channel spacing showing 1.2 dB insertion loss is obtained. A loss improvement near the theory was attained using minimum terrace area compared with a device using simple width taper.
Cross‐layer queueing analysis for aggregated ON–OFF arrivals with adaptive modulation and coding
Authors: Han Xingyu , Schormans John
Published: July 2016

Packet loss and delay in wireless networks is a function of both the traffic characteristics (e.g. load, burstiness) and the characteristic behaviour of the fading channel. In this study, the authors propose and analyse a new queue model in which the server process is controlled by the adaptive modulation and coding (AMC) algorithm, and with aggregated ON–OFF packet arrivals to a finite buffer. In the scenarios, where users require multiple services, aggregated ON–OFF arrivals approximate bursty behaviour better than the Poisson arrivals analysed in many earlier queueing models. They focus on the packet drop probability, the packet loss probability, the average queueing delay and the throughput, showing significant differences in these metrics between the cross‐layer models using aggregated ON–OFF arrivals and Poisson arrivals. This indicates that in wireless packet network performance evaluation, the traffic model is at least as important as the effect of the fading channel modelling.
Capacitance measurement method using sinusoidal voltage injection in isolating phase‐shifted full‐bridge DC–DC converter output stage
Authors: Hannonen Janne , Honkanen Jari , Ström Juha‐Pekka , Korhonen Juhamatti , Silventoinen Pertti , Räisänen Samuli
Published: July 2016

When it comes to the reliability of power electronics, wear‐out caused by ageing of electrolytic capacitors is a major concern. The capacitor ageing presents indicators such as a decrease in the capacitance and an increase in the equivalent series resistance, the detection of which can be used for capacitor health monitoring. In this study, the measurement of the output stage capacitance in an isolating DC–DC converter output stage is shown, which is used to assess the capacitor condition. In addition to presenting the method, fundamental issues related to the traditional capacitor ageing detection are discussed. The proposed method uses a sinusoidal voltage injection into the output voltage, which generates a current through the output stage capacitor. The capacitance is evaluated by the capacitor impedance, which is defined by the amplitudes of the applied voltage and the resulting capacitor current with the injection signal frequency. The method does not require hardware modifications to the converter or the measurement system, and it is executed online during the converter operation. The results show that the method is able to detect changes in the output stage capacitance regardless of the load.
LLC resonant converter for electric vehicle battery chargers
Authors: Hua Chih‐Chiang , Fang Yi‐Hsiung , Lin Cheng‐Wei
Published: July 2016

This study presents a new LLC resonant converter with two transformers in parallel for the electric vehicle battery charger. This topology achieves the zero‐voltage switching for main switches in the entire charging profile. In addition, the zero‐current switching for output rectifier diodes is extended under charging condition. The proposed charger provides a wide range output voltage for the battery system. Moreover, in order to maintain the high efficiency under charging, the charger adopts a bidirectional switch. At low‐output power condition, the charger uses one transformer to transfer the energy. Finally, the design procedure is provided and implemented in a prototype charger with the input DC link 400 V and the output voltage of 36–58 V. Experimental results are presented to demonstrate the system performance. The maximum power is up to 700 W and the peak efficiency is as high as 93.6%.
A canonical replica exchange molecular dynamics implementation with normal pressure in each replica
Authors: Peter Emanuel K. , Pivkin Igor V. , Shea Joan-Emma
Published: July 2016

In this paper, we present a new canonical replica exchange molecular dynamics (REMD) simulation method with normal pressure for all replicas (REMD-NV(p) T). This method is suitable for systems for which conventional constant NPT-setups are difficult to implement. In this implementation, each replica has an individual volume, with normal pressure maintained for each replica in the simulation. We derive a novel exchange term and validate this method on the structural properties of SPC/E water and dialanine (Ala2) in the bulk and in the presence of a graphene layer. Compared to conventional constant NPT-REMD and NVT-REMD simulations, we find that the structural properties of our new method are in good agreement with simulations in the NPT-ensemble at all temperatures. The structural properties of the systems considered are affected by high pressures at elevated temperatures in the constant NVT-ensemble, an effect that our method corrects for. Unprojected distributions reveal that essential motions of the peptide are affected by the presence of the barostat in the NPT implementation but that the dynamical eigenmodes of the NV(p)T method are in close quantitative agreement with the NVT-ensemble.
In a search for a shape maximizing packing fraction for two-dimensional random sequential adsorption
Authors: Cieśla Michał , Paja̧k Grzegorz , Ziff Robert M.
Published: July 2016

Random sequential adsorption of various two dimensional objects is studied in order to find a shape which maximizes the saturated packing fraction. This investigation was begun in our previous paper [Cieśla et al., Phys. Chem. Chem. Phys. 17, 24376 (2015)], where the densest packing was studied for smoothed dimers. Here this shape is compared with the smoothed n-mers, spherocylinders, and ellipses. It is found that the highest packing fraction out of the studied shapes is 0.584 05 ± 0.0001 and is obtained for ellipses having long-to-short axis ratio of 1.85 ± 0.07.
Quasi-monoenergetic ion beam acceleration by laser-driven shock and solitary waves in near-critical plasmas
Authors: Zhang W. L. , Qiao B. , Huang T. W. , Shen X. F. , You W. Y. , Yan X. Q. , Wu S. Z. , Zhou C. T. , He X. T.
Published: July 2016

Ion acceleration in near-critical plasmas driven by intense laser pulses is investigated theoretically and numerically. A theoretical model has been given for clarification of the ion acceleration dynamics in relation to different laser and target parameters. Two distinct regimes have been identified, where ions are accelerated by, respectively, the laser-induced shock wave in the weakly driven regime (comparatively low laser intensity) and the nonlinear solitary wave in the strongly driven regime (comparatively high laser intensity). Two-dimensional particle-in-cell simulations show that quasi-monoenergetic proton beams with a peak energy of 94.6 MeV and an energy spread 15.8% are obtained by intense laser pulses at intensity I0 = 3 × 1020 W/cm2 and pulse duration τ = 0.5 ps in the strongly driven regime, which is more advantageous than that got in the weakly driven regime. In addition, 233 MeV proton beams with narrow spread can be produced by extending τ to 1.0 ps in the strongly driven regime.
Numerical studies of wall–plasma interactions and ionization phenomena in an ablative pulsed plasma thruster
Authors: Yang Lei , Zeng Guangshang , Tang Haibin , Huang Yuping , Liu Xiangyang
Published: July 2016

Wall–plasma interactions excited by ablation controlled arcs are very critical physical processes in pulsed plasma thrusters (PPTs). Their effects on the ionization processes of ablated vapor into discharge plasma directly determine PPT performances. To reveal the physics governing the ionization phenomena in PPT discharge, a modified model taking into account the pyrolysis effect of heated polytetrafluoroethylene propellant on the wall–plasma interactions was developed. The feasibility of the modified model was analyzed by creating a one-dimensional simulation of a rectangular ablative PPT. The wall–plasma interaction results based on this modified model were found to be more realistic than for the unmodified model; this reflects the dynamic changes of the inflow parameters during discharge in our model. Furthermore, the temporal and spatial variations of the different plasma species in the discharge chamber were numerically studied. The numerical studies showed that polytetrafluoroethylene plasma was mainly composed of monovalent ions; carbon and fluorine ions were concentrated in the upstream and downstream discharge chamber, respectively. The results based on this modified model were in good agreement with the experimental formation times of the various plasma species. A large number of short-lived and highly ionized carbon and fluorine species (divalent and trivalent ions) were created during initial discharge. These highly ionized species reached their peak density earlier than the singly ionized species.
Noise-induced multistability in the regulation of cancer by genes and pseudogenes
Authors: Petrosyan K. G. , Hu Chin-Kun
Published: July 2016

We extend a previously introduced model of stochastic gene regulation of cancer to a nonlinear case having both gene and pseudogene messenger RNAs (mRNAs) self-regulated. The model consists of stochastic Boolean genetic elements and possesses noise-induced multistability (multimodality). We obtain analytical expressions for probabilities for the case of constant but finite number of microRNA molecules which act as a noise source for the competing gene and pseudogene mRNAs. The probability distribution functions display both the global bistability regime as well as even-odd number oscillations for a certain range of model parameters. Statistical characteristics of the mRNA’s level fluctuations are evaluated. The obtained results of the extended model advance our understanding of the process of stochastic gene and pseudogene expressions that is crucial in regulation of cancer.
Evolution of a Gaussian laser beam in warm collisional magnetoplasma
Authors: Jafari M. J. , Jafari Milani M. R. , Niknam A. R.
Published: July 2016

In this paper, the spatial evolution of an intense circularly polarized Gaussian laser beam propagated through a warm plasma is investigated, taking into account the ponderomotive force, Ohmic heating, external magnetic field, and collisional effects. Using the momentum transfer and energy equations, both modified electron temperature and electron density in plasma are obtained. By introducing the complex dielectric permittivity of warm magnetized plasma and using the complex eikonal function, coupled differential equations for beam width parameter are established and solved numerically. The effects of polarization state of laser and magnetic field on the laser spot size evolution are studied. It is observed that in case of the right-handed polarization, an increase in the value of external magnetic field causes an increase in the strength of the self-focusing, especially in the higher values, and consequently, the self-focusing occurs in shorter distance of propagation. Moreover, the results demonstrate the existence of laser intensity and electron temperature ranges where self-focusing can occur, while the beam diverges outside of these regions; meanwhile, in these intervals, there exists a turning point for each of intensity and temperature in which the self-focusing process has its strongest strength. Finally, it is found that the self-focusing effect can be enhanced by increasing the plasma frequency (plasma density).
Communication: Contrasting effects of glycerol and DMSO on lipid membrane surface hydration dynamics and forces
Authors: Schrader Alex M. , Cheng Chi-Yuan , Israelachvili Jacob N. , Han Songi
Published: July 2016

Glycerol and dimethyl sulfoxide (DMSO) are commonly used cryoprotectants in cellular systems, but due to the challenges of measuring the properties of surface-bound solvent, fundamental questions remain regarding the concentration, interactions, and conformation of these solutes at lipid membrane surfaces. We measured the surface water diffusivity at gel-phase dipalmitoylphosphatidylcholine (DPPC) bilayer surfaces in aqueous solutions containing ≤7.5 mol. % of DMSO or glycerol using Overhauser dynamic nuclear polarization. We found that glycerol similarly affects the diffusivity of water near the bilayer surface and that in the bulk solution (within 20%), while DMSO substantially increases the diffusivity of surface water relative to bulk water. We compare these measurements of water dynamics with those of equilibrium forces between DPPC bilayers in the same solvent mixtures. DMSO greatly decreases the range and magnitude of the repulsive forces between the bilayers, whereas glycerol increases it. We propose that the differences in hydrogen bonding capability of the two solutes leads DMSO to dehydrate the lipid head groups, while glycerol affects surface hydration only as much as it affects the bulk water properties. The results suggest that the mechanism of the two most common cryoprotectants must be fundamentally different: in the case of DMSO by decoupling the solvent from the lipid surface, and in the case of glycerol by altering the hydrogen bond structure and intermolecular cohesion of the global solvent, as manifested by increased solvent viscosity.
Control of near-field polarizations for nanoscale molecular orientational imaging
Authors: Mino T. , Saito Y. , Verma P.
Published: July 2016

Polarization-controlled tip-enhanced near-field Raman spectroscopic imaging is demonstrated using two characteristic dipoles induced at a metallic nano-tip. The polarization generated at the tip can be considered as a single dipole that can be switched from s to p by modulating the incident laser polarization. The s-dipole achieves highly selective molecular orientation imaging, while p-polarization provides comprehensive imaging in all directions. We discuss the controllability of near-field polarizations through the evaluation of the dipole orientation induced at the nano-tip. Polarization control and switching in near-field imaging are of tremendous advantage, as they allow the study of the molecular orientations in a sample, along with spectroscopic information.
Calculation of an optimized design of magnetic shields with integrated demagnetization coils
Authors: Sun Z. , Schnabel A. , Burghoff M. , Li L.
Published: July 2016

Magnetic shielding made from permalloy is frequently used to provide a time-stable magnetic field environment. A low magnetic field and low field gradients inside the shield can be obtained by using demagnetization coils through the walls, encircling edges of the shield. We first introduce and test the computational models to calculate magnetic properties of large size shields with thin shielding walls. We then vary the size, location and shape of the openings for the demagnetization coils at the corners of a cubic shield. It turns out that the effect on the shielding factor and the expected influence on the residual magnetic field homogeneity in the vicinity of the center of the shield is negligible. Thus, a low-cost version for the openings can be chosen and their size could be enlarged to allow for additional cables and easier handling. A construction of a shield with beveled edges and open corners turned out to substantially improve the shielding factor.
The H60Si6C54 heterofullerene as high-capacity hydrogen storage medium
Authors: Yong Yongliang , Zhou Qingxiao , Li Xiaohong , Lv Shijie
Published: July 2016

With the great success in Si atoms doped C60 fullerene and the well-established methods for synthesis of hydrogenated carbon fullerenes, this leads naturally to wonder whether Si-doped fullerenes are possible for special applications such as hydrogen storage. Here by using first-principles calculations, we design a novel high-capacity hydrogen storage material, H60Si6C54 heterofullerene, and confirm its geometric stability. It is found that the H60Si6C54 heterofullerene has a large HOMO-LUMO gap and a high symmetry, indicating it is high chemically stable. Further, our finite temperature simulations indicate that the H60Si6C54 heterofullerene is thermally stable at 300 K. H2 molecules would enter into the cage from the Si-hexagon ring because of lower energy barrier. Through our calculation, a maximum of 21 H2 molecules can be stored inside the H60Si6C54 cage in molecular form, leading to a gravimetric density of 11.11 wt% for 21H2@H60Si6C54 system, which suggests that the hydrogenated Si6C54 heterofullerene could be suitable as a high-capacity hydrogen storage material.
Ractopamine with dietary lysine concentrations above basal requirements of finishing barrows improves growth performance, carcass traits and modifies the mTor signalling pathway
Authors: Ferreira M. S. S. , Araújo T. S. , Alves A. C. , Porto L. C. J. , Schinckel A. P. , Rambo Z. J. , Cantarelli V. S. , Zangeronimo M. G. , Sousa R. V.
Published: July 2016

A 28-day study was conducted to evaluate the effects of three step-up levels of ractopamine hydrochloride (RAC) together with two additional levels of standardised ileal digestible lysine (Lys) above the basal requirements on growth performance, carcass characteristics and the mechanism of action on adipose and muscle tissue. In all, 108 finishing pigs (initial bodyweight 75.37 kg ± 2.88) were used for growth data and 54 pigs for carcass data. Samples from 18 pigs were used for the molecular study. Pigs were blocked by initial bodyweight and allotted to one of the following nine treatments: negative control (NC) without addition of RAC or Lys supplementation, constant 7.5 mg/kg RAC, 5 mg/kg RAC for 14 days, followed by 10 mg/kg for 14 days (Step-up 1), 5 mg/kg RAC for 21 days, followed by 10 mg/kg for 7 days (Step-up 2) and 5 mg/kg RAC for 7 days followed by 10 mg/kg for 21 days (Step up 3); on constant and step-up treatments were added 15% or 30% Lys above the basal level, giving a 4 × 2 + 1 factorial with six replicates. Loin muscle and fat tissue were collected for carcass-characteristic analysis and western blotting for p-AKT, p-P70S6K and carnitine palmitoyltransferase I. Feeding RAC increased gain to feed ratio and efficiency of energy utilisation (EF) from Day 0 to Day 13 (P < 0.05) compared with NC. From Day 14 to Day 27, greater average daily gain (ADG) was observed in RAC-treated animals (P < 0.05), except in the Step-up 2 with 30% additional Lys. During the second half of the trial, RAC positively affected ADG, gain to feed ratio and EF (P < 0.01), while a Step-1 versus Step-2 effect was observed for ADG (P < 0.03). For the overall period, RAC-treated pigs had greater ADG than did NC pigs (P < 0.05). An average of 8.1% improvement on feed efficiency and 30% improvement on EF were observed for RAC-fed pigs in comparison to NC pigs (P < 0.05). Chilled carcass weight and loin eye area were increased in pigs fed RAC (P < 0.01). Western blotting showed greater p-P70S6K in muscle samples from pigs fed RAC with 15% additional Lys than in those from NC pigs (P < 0.10). RAC was effective at improving efficiency of production. Lys supplementation of 15% was enough for optimal performance of the pigs in the present study; however, step-up programs did not outperform RAC-constant programs. Results of the present study suggest that RAC stimulates protein synthesis through the mTOR signalling pathway.