bluuebunny/crossref_metadata_2025 huggingface dataset:
Vaccines and diagnostics for zoonotic schistosomiasis japonica
Authors: YOU HONG , MCMANUS DONALD P.
Published: October 2014

Schistosomiasis is one of the most prevalent, insidious and serious of the tropical parasitic diseases. Although the effective anthelmintic drug, praziquantel, is widely available and cheap, it does not protect against re-infection, drug-resistant schistosome may evolve and mass drug administration programmes based around praziquantel are probably unsustainable long term. Whereas protective anti-schistosome vaccines are not yet available, the zoonotic nature of Schistosoma japonicum provides a novel approach for developing a transmission-blocking veterinary vaccine in domestic animals, especially bovines, which are major reservoir hosts, being responsible for up to 90% of environmental egg contamination in China and the Philippines. However, a greater knowledge of schistosome immunology is required to understand the processes associated with anti-schistosome protective immunity and to reinforce the rationale for vaccine development against schistosomiasis japonica. Importantly as well, improved diagnostic tests, with high specificity and sensitivity, which are simple, rapid and able to diagnose light S. japonicum infections, are required to determine the extent of transmission interruption and the complete elimination of schistosomiasis following control efforts. This article discusses aspects of the host immune response in schistosomiasis, the current status of vaccine development against S. japonicum and reviews approaches for diagnosing and detecting schistosome infections in mammalian hosts.
Physical activity and dietary habits among Moroccan adolescents
Authors: Hamrani Abdeslam , Mehdad Slimane , El Kari Khalid , El Hamdouchi Asmaa , El Menchawy Imane , Belghiti Hakim , El Mzibri Mohammed , Musaiger Abdulrahman O , Al-Hazzaa Hazzaa M , Hills Andrew P , Mokhtar Najat , Aguenaou Hassan
Published: October 2014

Objective

The study aimed to detail the lifestyle (physical activity and dietary habits) of Moroccan adolescents.

Design

Cross-sectional study undertaken in the framework of the ATLS (Arab Teens Lifestyle Study).

Setting

Physical activity and dietary habits were determined using a validated questionnaire in public secondary schools.

Subjects

A total of 669 adolescents aged 15·0–19·9 years were randomly recruited from Kenitra, Morocco.

Results

Physical activity patterns and intensity differed between genders. As anticipated, male adolescents were more active than female adolescents across a typical week and engaged in more vigorous-intensity physical activity than female adolescents, who spent more time than male adolescents in moderate-intensity physical activity. Of particular concern was that one in five of the adolescents surveyed was inactive, with almost 45 % of the sample reporting television viewing for more than 2 h/d and 38 % engaged in computer use for a similar period. From a dietary perspective, most adolescents reported that they do not take breakfast or consume milk and dairy products, fruits and vegetables on a daily basis. In contrast, most reported consumption of doughnuts, cakes, candy and chocolate more than three times per week and approximately 50 % consumed sugary drinks more than three times per week.

Conclusions

Based on a continuation of the self-reported lifestyle behaviours, adolescents in the present study are at risk of developing chronic diseases. Education programmes are urgently needed to assist in the promotion of a healthy lifestyle and reduce the likelihood of overweight and obesity and related health risks among young people.
The effect of stress on microbial growth
Authors: Lyte Mark
Published: October 2014

The neurophysiological response of an animal to stress involves the production of a number of stress-related neurochemicals including the catecholamines norepinephrine and epinephrine. It is generally believed that such neurochemicals belong exclusively to the animal kingdom and that any role such neurochemicals play in the infective process is largely confined to host physiology and immunology-related parameters. This, however, is wholly incorrect as many of the bacterial species that are known to cause infections possess the capacity to not only recognize neuroendocrine hormones produced by the host in response to stress, but also synthesize the very same neurochemicals. Given this, infectious microorganisms are capable of directly responding to the neurochemical outflow resulting from a stress event and initiating pathogenic processes. Although the neuroendocrine environment of the lung following a stress event is not fully understood, it most likely possesses abundant levels of stress-related neurochemicals due to its rich blood supply and rich noradrenergic tissue innervation. The ability of microorganisms to recognize and produce neurochemicals that can influence the host, known as microbial endocrinology, provides for a mechanistic basis with which to examine the ability of stress to influence health and susceptibility to disease.
Community transcriptomics reveals unexpected high microbial diversity in acidophilic biofilm communities
Authors: Aliaga Goltsman Daniela S , Comolli Luis R , Thomas Brian C , Banfield Jillian F
Published: October 2014

A fundamental question in microbial ecology relates to community structure, and how this varies across environment types. It is widely believed that some environments, such as those at very low pH, host simple communities based on the low number of taxa, possibly due to the extreme environmental conditions. However, most analyses of species richness have relied on methods that provide relatively low ribosomal RNA (rRNA) sampling depth. Here we used community transcriptomics to analyze the microbial diversity of natural acid mine drainage biofilms from the Richmond Mine at Iron Mountain, California. Our analyses target deep pools of rRNA gene transcripts recovered from both natural and laboratory-grown biofilms across varying developmental stages. In all, 91.8% of the ∼254 million Illumina reads mapped to rRNA genes represented in the SILVA database. Up to 159 different taxa, including Bacteria, Archaea and Eukaryotes, were identified. Diversity measures, ordination and hierarchical clustering separate environmental from laboratory-grown biofilms. In part, this is due to the much larger number of rare members in the environmental biofilms. Although Leptospirillum bacteria generally dominate biofilms, we detect a wide variety of other Nitrospira organisms present at very low abundance. Bacteria from the Chloroflexi phylum were also detected. The results indicate that the primary characteristic that has enabled prior extensive cultivation-independent ‘omic’ analyses is not simplicity but rather the high dominance by a few taxa. We conclude that a much larger variety of organisms than previously thought have adapted to this extreme environment, although only few are selected for at any one time.
Ecological roles of dominant and rare prokaryotes in acid mine drainage revealed by metagenomics and metatranscriptomics
Authors: Hua Zheng-Shuang , Han Yu-Jiao , Chen Lin-Xing , Liu Jun , Hu Min , Li Sheng-Jin , Kuang Jia-Liang , Chain Patrick S G , Huang Li-Nan , Shu Wen-Sheng
Published: October 2014

High-throughput sequencing is expanding our knowledge of microbial diversity in the environment. Still, understanding the metabolic potentials and ecological roles of rare and uncultured microbes in natural communities remains a major challenge. To this end, we applied a ‘divide and conquer’ strategy that partitioned a massive metagenomic data set (>100 Gbp) into subsets based on K-mer frequency in sequence assembly to a low-diversity acid mine drainage (AMD) microbial community and, by integrating with an additional metatranscriptomic assembly, successfully obtained 11 draft genomes most of which represent yet uncultured and/or rare taxa (relative abundance <1%). We report the first genome of a naturally occurring Ferrovum population (relative abundance >90%) and its metabolic potentials and gene expression profile, providing initial molecular insights into the ecological role of these lesser known, but potentially important, microorganisms in the AMD environment. Gene transcriptional analysis of the active taxa revealed major metabolic capabilities executed in situ, including carbon- and nitrogen-related metabolisms associated with syntrophic interactions, iron and sulfur oxidation, which are key in energy conservation and AMD generation, and the mechanisms of adaptation and response to the environmental stresses (heavy metals, low pH and oxidative stress). Remarkably, nitrogen fixation and sulfur oxidation were performed by the rare taxa, indicating their critical roles in the overall functioning and assembly of the AMD community. Our study demonstrates the potential of the ‘divide and conquer’ strategy in high-throughput sequencing data assembly for genome reconstruction and functional partitioning analysis of both dominant and rare species in natural microbial assemblages.
miR-24 limits aortic vascular inflammation and murine abdominal aneurysm development
Authors: Maegdefessel Lars , Spin Joshua M. , Raaz Uwe , Eken Suzanne M. , Toh Ryuji , Azuma Junya , Adam Matti , Nagakami Futoshi , Heymann Helen M. , Chernugobova Ekaterina , Jin Hong , Roy Joy , Hultgren Rebecka , Caidahl Kenneth , Schrepfer Sonja , Hamsten Anders , Eriksson Per , McConnell Michael V. , Dalman Ronald L. , Tsao Philip S.
Published: October 2014

Identification and treatment of abdominal aortic aneurysm (AAA) remain among the most prominent challenges in vascular medicine. MicroRNAs (miRNAs) are crucial regulators of cardiovascular pathology and represent intriguing targets to limit AAA expansion. Here we show, by using two established murine models of AAA disease along with human aortic tissue and plasma analysis, that miR-24 is a key regulator of vascular inflammation and AAA pathology. In vivo and in vitro studies reveal chitinase 3-like 1 (Chi3l1) to be a major target and effector under the control of miR-24, regulating cytokine synthesis in macrophages as well as their survival, promoting aortic smooth muscle cell migration and cytokine production, and stimulating adhesion molecule expression in vascular endothelial cells. We further show that modulation of miR-24 alters AAA progression in animal models, and that miR-24 and CHI3L1 represent novel plasma biomarkers of AAA disease progression in humans.
Observation of strongly entangled photon pairs from a nanowire quantum dot
Authors: Versteegh Marijn A. M. , Reimer Michael E. , Jöns Klaus D. , Dalacu Dan , Poole Philip J. , Gulinatti Angelo , Giudice Andrea , Zwiller Val
Published: October 2014

A bright photon source that combines high-fidelity entanglement, on-demand generation, high extraction efficiency, directional and coherent emission, as well as position control at the nanoscale is required for implementing ambitious schemes in quantum information processing, such as that of a quantum repeater. Still, all of these properties have not yet been achieved in a single device. Semiconductor quantum dots embedded in nanowire waveguides potentially satisfy all of these requirements; however, although theoretically predicted, entanglement has not yet been demonstrated for a nanowire quantum dot. Here, we demonstrate a bright and coherent source of strongly entangled photon pairs from a position-controlled nanowire quantum dot with a fidelity as high as 0.859±0.006 and concurrence of 0.80±0.02. The two-photon quantum state is modified via the nanowire shape. Our new nanoscale entangled photon source can be integrated at desired positions in a quantum photonic circuit, single-electron devices and light-emitting diodes.
Assessment of the statistical significance of classifications in infrared spectroscopy based diagnostic models
Authors: Pérez-Guaita David , Kuligowski Julia , Garrigues Salvador , Quintás Guillermo , Wood Bayden R.
Published: October 2014

Permutation testing in the evaluation of the statistical significance for infrared based classification of biological samples.
A sensitive heterogeneous biotin–streptavidin enzyme-linked immunosorbent assay for the determination of di-(2-ethylhexyl)phthalate (DEHP) in beverages using a specific polyclonal antibody
Authors: Sun Ruiyan , Zhuang Huisheng
Published: October 2014

Di-(2-ethylhexyl)phthalate (DEHP) is one of the long-chain or high-molecular-weight compounds of the phthalic acid diester (PAEs) family, which is the most commonly used plasticizer and additive.
Trace copper ion detection by the suppressed decolorization of chromotrope 2R complex
Authors: Fu Lili , Xiong Yuan , Chen Shu , Long Yunfei
Published: October 2014

Chromotrope 2R (CR) is a monoazo dye, which can be easily degraded under ultraviolet C (UVC) light irradiation. However, the degradation extent of CR is suppressed after it is chelated with Cu2+ ions to form a coordination complex (Cu2+–CR).
Fluorometric assay of integrin activity with a small-molecular probe that senses the binding site microenvironment
Authors: Komatsu Toru , Takeda Aoi , Hanaoka Kenjiro , Terai Takuya , Ueno Tasuku , Tada Yukio , Nagano Tetsuo , Urano Yasuteru
Published: October 2014

We have developed a small-molecular probe, consisting of cyclic RGD pentapeptide bearing a nitrobenzoxadiazole fluorophore at the 4′-residue, which detects integrin αVβ3 activity in terms of fluorescence intensity decrease.
Two act as one: unexpected dimers of catechol direct a solid-state [2+2] photodimerization in a six-component hydrogen-bonded assembly
Authors: Papaefstathiou Giannis S. , Duncan Andrew J. E. , MacGillivray Leonard R.
Published: October 2014

Catechol self-assembles as a dimer to function as template that directs a [2+2] photodimerization in the solid state.
Polyoxometalates as inorganic chiral ligands for the synthesis of chiral nanoparticles
Authors: Shi Lei , Li Bao , Wu Lixin
Published: October 2014

Inherent chiral polyoxometalates are introduced as a new kind of inorganic chiral ligands for the synthesis of chiral metal nanoparticles.
A dual FRET based fluorescent probe as a multiple logic system
Authors: Zhou Xin , Wu Xue , Yoon Juyoung
Published: October 2014

The dual FRET based fluorescent probe showed distinguished responses towards Fe3+ and Hg2+, making it an ideal candidate for multiple logic operations at the molecular level.
A large-scale superhydrophobic surface-enhanced Raman scattering (SERS) platform fabricated via capillary force lithography and assembly of Ag nanocubes for ultratrace molecular sensing
Authors: Rui Tan Joel Ming , Ruan Justina Jiexin , Lee Hiang Kwee , Phang In Yee , Ling Xing Yi
Published: October 2014

A high-throughput fabrication of a stable and uniform superhydrophobic SERS platform is demonstrated. It is able to detect trace molecules at ultra-low detection limit of 10−17 M (10 aM) using just 4 μL of analyte solutions.
Reductive dechlorination of BCl3 for efficient ammonia borane regeneration
Authors: Tan Yingbin , Zhang Lijun , Chen Xiaowei , Yu Xuebin
Published: October 2014

Chemical regeneration of ammonia borane (AB) from its digestion product of H2-depleted AB, BCl3, has been implemented based on reduction and ammoniation reactions.
Benzene absorption in a protuberant-grid-type zinc(ii)–organic framework triggered by the migration of guest water molecules
Authors: Tseng Tien-Wen , Luo Tzuoo-Tsair , Tsai Chang-Hsiu , Chen Chun-Chi , Lee Gene-Hsiang , Wang Chih-Chieh , Lu Kuang-Lieh
Published: October 2014

Benzene molecules are reported to be easily and regularly absorbed into specific channels in a 2D protuberant-grid-type Zn(ii)–organic framework, which consists of racemic interdigitated bilayers.
Remarkable LnIII3FeIII2 clusters with magnetocaloric effect and slow magnetic relaxation
Authors: Li Han , Shi Wei , Niu Zheng , Zhou Jing-Min , Xiong Gang , Li Lei-Lei , Cheng Peng
Published: October 2014

Two 3d–4f clusters were reported: Gd3Fe2 possesses significant magnetic entropy change and slow magnetic relaxation is observed in Dy3Fe2.
Methanolysis of ammonia borane by shape-controlled mesoporous copper nanostructures for hydrogen generation
Authors: Yao Qilu , Huang Ming , Lu Zhang-Hui , Yang Yuwen , Zhang Yuxin , Chen Xiangshu , Yang Zhen
Published: October 2014

A facile and scaleable wet-chemical method has been successfully applied to the synthesis of diverse mesoporous Cu nanostructures, which exhibited excellent catalytic activity for hydrogen generation from the methanolysis of AB at room temperature.
A medium throughput device to study the effects of combinations of surface strains and fluid-flow shear stresses on cells
Authors: Sinha R. , Le Gac S. , Verdonschot N. , van den Berg A. , Koopman B. , Rouwkema J.
Published: October 2014

A device is reported to screen for the effects on cells of all combinations of five surface strains and five fluid-flow shear stresses, each with four replicates (total 100 units).
Cationic amphiphilic calixarenes to compact DNA into small nanoparticles for gene delivery
Authors: Rodik Roman V. , Anthony Anne-Sophie , Kalchenko Vitaly I. , Mély Yves , Klymchenko Andrey S.
Published: October 2014

Cationic amphiphilic calixarenes with longer alkyl chains are less cytotoxic and their virus-sized DNA nanoparticles exhibit higher transfection efficiency.
Theoretical investigation on a series of novel S,S-dioxide diarylethenes with abnormal photochromic properties and design of new dyads
Authors: Zhang Zhi-Xiang , Bai Fu-Quan , Li Li , Zhang Hong-Xing
Published: October 2014

A novel diarylethene shows an abnormal conjugation system switch in a photochromic reaction, according to which new dyads were designed.
Gradual thickness-dependent enhancement of the thermoelectric properties of PEDOT:PSS nanofilms
Authors: Yoo Dohyuk , Son Woohyun , Kim Seyul , Lee Jung Joon , Lee Seung Hwan , Choi Hyang Hee , Kim Jung Hyun
Published: October 2014

We investigated the spinning speed dependent surface composition for TE performance with PEDOT:PSS films. The Seebeck coefficient and electrical conductivity of PEDOT:PSS film decrease as the spinning speed elevates. The thicker nanofilm exhibited the best properties in terms of the electrical conductivity and Seebeck coefficient.
Characteristics of low temperature biomass gasification and syngas release behavior using hot slag
Authors: Sun Yongqi , Zhang Zuotai , Seetharaman Sridhar , Liu Lili , Wang Xidong
Published: October 2014

Syngas production was achieved using low temperature biomass gasification combined with heat recovery from hot slag.
Advanced micro/nanocapsules for self-healing smart anticorrosion coatings
Authors: Wei Huige , Wang Yiran , Guo Jiang , Shen Nancy Z. , Jiang Dawei , Zhang Xi , Yan Xingru , Zhu Jiahua , Wang Qiang , Shao Lu , Lin Hongfei , Wei Suying , Guo Zhanhu
Published: October 2014

Smart self-healing micro/nanocontainers that heal cracks in the coating by releasing active compounds in response to external stimuli were reviewed.
Flexible, in-plane, and all-solid-state micro-supercapacitors based on printed interdigital Au/polyaniline network hybrid electrodes on a chip
Authors: Hu Haibo , Zhang Kun , Li Shuxin , Ji Shulin , Ye Changhui
Published: October 2014

The combination of laser printing technology and anin situelectropolymerization approach enables the fabrication of flexible, in-plane, and all-solid-state micro-supercapacitors with low-cost.
Synthesis and lithium-storage properties of MnO/reduced graphene oxide composites derived from graphene oxide plus the transformation of Mn(vi) to Mn(ii) by the reducing power of graphene oxide
Authors: Zhao Guixia , Huang Xiubing , Wang Xiangke , Connor Paul , Li Jiaxing , Zhang Shouwei , Irvine John T. S.
Published: October 2014

MnO/rGO composites were obtained via calcining the precursors (i.e., δ-MnO2/GO composites) at 500 °C in Ar, GO serves as a reductant by releasing CO during its thermolysis.
Crystallization and concentration modulated tunable upconversion luminescence of Er3+ doped PZT nanofibers
Authors: Fu Yike , Gong Siyu , Liu Xiaofeng , Xu Gang , Ren Zhaohui , Li Xiang , Han Gaorong
Published: October 2014

Spectral tunable Er doped PZT nanofibers are fabricated by controlling crystallization and doping conditions using electrospinning for electro-mechano-optical microdevices.
Circular trimers of gelatinase B/matrix metalloproteinase-9 constitute a distinct population of functional enzyme molecules differentially regulated by tissue inhibitor of metalloproteinases-1
Authors: Vandooren Jennifer , Born Benjamin , Solomonov Inna , Zajac Ewa , Saldova Radka , Senske Michael , Ugarte-Berzal Estefanía , Martens Erik , Van den Steen Philippe E. , Van Damme Jo , Garcia-Pardo Angeles , Froeyen Matheus , Deryugina Elena I. , Quigley James P. , Moestrup Søren K. , Rudd Pauline M. , Sagi Irit , Opdenakker Ghislain
Published: October 2014

Gelatinase B/matrix metalloproteinase-9 (MMP-9) (EC 3.4.24.35) cleaves many substrates and is produced by most cell types as a zymogen, proMMP-9, in complex with the tissue inhibitor of metalloproteinases-1 (TIMP-1). Natural proMMP-9 occurs as monomers, homomultimers and heterocomplexes, but our knowledge about the overall structure of proMMP-9 monomers and multimers is limited. We investigated biochemical, biophysical and functional characteristics of zymogen and activated forms of MMP-9 monomers and multimers. In contrast with a conventional notion of a dimeric nature of MMP-9 homomultimers, we demonstrate that these are reduction-sensitive trimers. Based on the information from electrophoresis, AFM and TEM, we generated a 3D structure model of the proMMP-9 trimer. Remarkably, the proMMP-9 trimers possessed a 50-fold higher affinity for TIMP-1 than the monomers. In vivo, this finding was reflected in a higher extent of TIMP-1 inhibition of angiogenesis induced by trimers compared with monomers. Our results show that proMMP-9 trimers constitute a novel structural and functional entity that is differentially regulated by TIMP-1.
Vinculin-dependent actin bundling regulates cell migration and traction forces
Authors: Jannie Karry M. , Ellerbroek Shawn M. , Zhou Dennis W. , Chen Sophia , Crompton David J. , García Andrés J. , DeMali Kris A.
Published: October 2014

Vinculin binding to actin filaments is thought to be critical for force transduction within a cell, but direct experimental evidence to support this conclusion has been limited. In the present study, we found mutation (R1049E) of the vinculin tail impairs its ability to bind F-actin, stimulate actin polymerization, and bundle F-actin in vitro. Further, mutant (R1049E) vinculin expressing cells are altered in cell migration, which is accompanied by changes in cell adhesion, cell spreading and cell generation of traction forces, providing direct evidence for the critical role of vinculin in mechanotransduction at adhesion sites. Lastly, we discuss the viability of models detailing the F-actin-binding surface on vinculin in the context of our mutational analysis.
Vascular injury in diabetic db/db mice is ameliorated by atorvastatin: role of Rac1/2-sensitive Nox-dependent pathways
Authors: Bruder-Nascimento Thiago , Callera Glaucia E. , Montezano Augusto C. , He Ying , Antunes Tayze T. , Cat Aurelie Nguyen Dinh , Tostes Rita C. , Touyz Rhian M.
Published: October 2014

Oxidative stress [increased bioavailability of reactive oxygen species (ROS)] plays a role in the endothelial dysfunction and vascular inflammation, which underlie vascular damage in diabetes. Statins are cholesterol-lowering drugs that are vasoprotective in diabetes through unknown mechanisms. We tested the hypothesis that atorvastatin decreases NADPH oxidase (Nox)-derived ROS generation and associated vascular injury in diabetes. Leprdb/Leprdb (db/db) mice, a model of Type 2 diabetes and control Leprdb/Lepr+ (db/+) mice were administered atorvastatin (10 mg/kg per day, 2 weeks). Atorvastatin improved glucose tolerance in db/db mice. Systemic and vascular oxidative stress in db/db mice, characterized by increased plasma TBARS (thiobarbituric acid-reactive substances) levels and exaggerated vascular Nox-derived ROS generation respectively, were inhibited by atorvastatin. Cytosol-to-membrane translocation of the Nox regulatory subunit p47phox and the small GTPase Rac1/2 was increased in vessels from db/db mice compared with db/+ mice, an effect blunted by atorvastatin. The increase in vascular Nox1/2/4 expression and increased phosphorylation of redox-sensitive mitogen-activated protein kinases (MAPKs) was abrogated by atorvastatin in db/db mice. Pro-inflammatory signalling (decreased IκB-α and increased NF-κB p50 expression, increased NF-κB p65 phosphorylation) and associated vascular inflammation [vascular cell adhesion molecule-1 (VCAM-1) expression and vascular monocyte adhesion], which were increased in aortas of db/db mice, were blunted by atorvastatin. Impaired acetylcholine (Ach)- and insulin (INS)-induced vasorelaxation in db/db mice was normalized by atorvastatin. Our results demonstrate that, in diabetic mice, atorvastatin decreases vascular oxidative stress and inflammation and ameliorates vascular injury through processes involving decreased activation of Rac1/2 and Nox. These findings elucidate redox-sensitive and Rac1/2-dependent mechanisms whereby statins protect against vascular injury in diabetes.
Stable multiple non‐Foster circuits loaded waveguide for broadband non‐dispersive fast‐wave propagation
Authors: Long J. , Sievenpiper D.F.
Published: October 2014

Periodically loading non‐Foster circuits (NFCs) in a conventional waveguide has been proved to be possible for achieving broadband non‐dispersive fast‐wave (FW) propagation. However, the unconditional stability of such structures has been argued due to the multiple NFC loadings. Despite the potential instability, it is demonstrated that the NFC‐loaded waveguide can still be stable for specific terminations, in particular, with the 50 Ω load that is commonly used in radio frequency/microwave applications. For purpose of demonstration, a NFC‐loaded waveguide that contains substantially more unit cells than in prior work has been designed and measured, showing a stable and causal FW propagation with a 1.2 c phase velocity over the bandwidth of 80–120 MHz.
Quad‐band bandpass filter design by embedding dual‐band bandpass filter with dual‐mode notch elements
Authors: Cui Chenwei , Liu Yun
Published: October 2014

A quad‐band bandpass filter of compact dimensions by embedding several dual‐mode notch elements into a stub‐type dual‐band bandpass filter is presented, and the four passbands are achieved by splitting the two passbands of the dual‐band bandpass filter with two notch bands generated by the dual‐mode notch elements. A prototype filter with passbands located at 1.4–1.7, 2.1–2.3, 3.3–3.6 and 5.2–5.4 GHz is designed with the help of optimisation methods. Good agreement between simulations and measurements are achieved, demonstrating good features such as controllable and wide bandwidths, higher filter order, compact dimensions and high isolations.
Performance analysis of a multi‐hop power line communication system over log‐normal fading in presence of impulsive noise
Authors: Dubey Ankit , Mallik Ranjan K. , Schober Robert
Published: October 2014

The authors present a study on the end‐to‐end average bit error rate (BER), the average channel capacity and the outage performance of a multi‐hop power line communication (PLC) system equipped with decode‐and‐forward (DF) relays. To combat the issue of distance dependent signal attenuation, multi‐hop data transmission has recently been introduced for PLC systems. However, apart from the distance dependent signal attenuation, PLC systems also suffer from (i) the variation in signal amplitude (fading) because of reflections and (ii) impulsive noise. Thus, in this study, the channel for each hop of the multi‐hop PLC system is modelled by a log‐normal fading amplitude, which is clubbed to a distance dependent signal attenuation factor. To consider the effect of the impulsive noise along with the background noise, the additive noise at each node is modelled by a Bernoulli–Gaussian process. Analytical expressions for the end‐to‐end average BER for binary phase‐shift keying, the average channel capacity and the outage probability are obtained. The merit of the multi‐hop PLC system over a conventional direct transmission PLC system for fixed transmission power is shown through numerical results. The authors' results show that with increasing number of DF relays, the end‐to‐end average BER, the average channel capacity and the outage performance improve.
Performance comparison of analogue inter‐satellite microwave photonics link using intensity modulation with direct detection and phase modulation with interferometric detection
Authors: Zhu Zihang , Zhao Shanghong , Li Yongjun , Li Xuan
Published: October 2014

The performance of optical inter‐satellite communications using microwave photonics technologies employing intensity modulation with direct detection (IMDD) and phase modulation (PM) with interferometric detection are investigated and demonstrated with a numerical example. The theoretical model considering the saturated gain and amplifier spontaneous emission noise of optical booster amplifier and optical preamplifier is constructed for both architectures. Furthermore, the authors compare the performance of PM with interferometric detection to optimum biased IMDD in terms of radio frequency (RF) gain, RF noise figure and compression dynamic range (CDR). The numerical results show that the PM with interferometric detection can achieve better RF gain, RF noise figure and CDR than the optimum biased IMDD link as the laser output power is lower than 14.34, 12.45 and 4.2 dBm, respectively.
Single phase three‐level neutral‐point‐clamped quasi‐Z‐source inverter
Authors: Husev Oleksandr , Roncero‐Clemente Carlos , Romero‐Cadaval Enrique , Vinnikov Dmitri , Stepenko Serhii
Published: October 2014

This study presents a novel three‐level neutral‐point‐clamped quasi‐Z‐source inverter in the single‐stage buck‐boost multilevel inverter family. The topology was derived by combining the properties of the quasi‐Z‐source network with those of a three‐level neutral point clamped inverter. It features such advantages as low voltage stress of the switches, single‐stage buck‐boost power conversion, continuous input current, short‐circuit withstandability and low total harmonic distortion of the output voltage and current. The authors present a steady state analysis of the topology along with a special modulation technique to distribute shoot‐through states during the whole fundamental period. Component design guidelines for a single‐phase case study system are described. All the findings have been confirmed by simulations and experiments. The topology could be recommended for applications requiring continuous input current, high input voltage gain and enhanced quality of the output voltage.
Experimental validation of minimum cost function‐based model predictive converter control with efficient reference tracking
Authors: Uddin Muslem , Mekhilef Saad , Rivera Marco
Published: October 2014

This study proposes a robust and powerful finite control set‐model predictive control (MPC) algorithm to control the load current with lower total harmonic distortion and efficient reference tracking. In this control, the cost functions are determined for all the possible switching states of the converter and a switching state is selected corresponding to the minimum cost function for actuating the converter in the next sampling time period. To justify the performance of the proposed MPC scheme, a comprehensive study with the carrier‐based pulse‐width modulation, hysteresis current control and proposed minimum cost function‐based MPC of the three‐phase load current has been verified in MATLAB Simulink as well as the validation with dSPACE RTI1104 experimentation. This study validates the robustness of the proposed minimum cost function‐based MPC control with a RL‐load and three‐phase induction motor (IM) load. The simulation and experimental results justifies the proposed MPC algorithm with potential tracking of the RL‐load current corresponding to the reference current with lower harmonic contents as well as tracking of predictive torque and flux compared to the nominal torque and reference flux of IM, respectively.
Adaptive second order sliding mode control of doubly fed induction generator in wind energy conversion system
Authors: Dash P. K. , Patnaik R. K.
Published: October 2014

A dynamic synchronous d-q reference frame based modeling and a novel adaptive higher order sliding mode control theory for doubly fed induction generator (DFIG) based wind energy conversion system (WECS) have been proposed in this paper. As depicted from the literature, the sliding mode control strategy involving computation of converter currents introduces some inaccuracies for optimal extraction of the power references of the DFIG. On the contrary, the proposed method contributes with some important features such as chatter-free performance and heftiness in terms of transient response of the non-linear systems subjected to dynamic conditions such as lower and higher wind speeds. Consequently, a higher order sliding mode controller using the active and reactive power of the DFIG as controller inputs has been proposed in this paper. As compared with the other two methods, the proposed higher order sliding mode power control souvenirs a significantly improved as well as stable performance of the DFIG based WECS in terms of reduced settling time as well as quickly damping out the oscillations exhibited by the system. The robustness and stability of the proposed control strategy has been validated in MATLAB environment, in terms of the comparison of its performance with traditional proportional-integral and existing first-order sliding mode controller (employing converter current as input) subjected to a wide range of disturbances for sub and super synchronous mode of operation of the DFIG subjected to lower and higher wind speeds along with the available practical wind speed data, as depicted in the simulation and result section.
Frequency stabilization of spin-torque-driven oscillations by coupling with a magnetic nonlinear resonator
Authors: Kudo Kiwamu , Suto Hirofumi , Nagasawa Tazumi , Mizushima Koichi , Sato Rie
Published: October 2014

The fundamental function of any oscillator is to produce a waveform with a stable frequency. Here, we show a method of frequency stabilization for spin-torque nano-oscillators (STNOs) that relies on coupling with an adjacent nanomagnet through the magnetic dipole–dipole interaction. It is numerically demonstrated that highly stable oscillations occur as a result of mutual feedback between an STNO and a nanomagnet. The nanomagnet acts as a nonlinear resonator for the STNO. This method is based on the nonlinear behavior of the resonator and can be considered as a magnetic analogue of an optimization scheme in nanoelectromechanical systems. The oscillation frequency is most stabilized when the nanomagnet is driven at a special feedback point at which the feedback noise between the STNO and resonator is completely eliminated.
Thermal-to-electric energy conversion using ferroelectric film capacitors
Authors: Kozyrev A. B. , Platonov R. A. , Soldatenkov O. I.
Published: October 2014

The capacitive ferroelectric thermoelectric converter harvesting electrical energy through non-linear capacitance variation caused by changes in temperature is analyzed. The ferroelectric material used was the thin (0.5 μm) Ba0.3Sr0.7TiO3 film. On the basis of experimental dependencies of the ferroelectric film permittivity on temperature ranging from 100 K to 350 K under different electric fields up to 80 V/μm, the optimum values of operating temperatures and electric field for the energy harvesting optimization were determined. For the temperature oscillations of ±15 K around room temperature and electric field about 40 V/μm, the harvested energy was estimated as 30 mJ/cm3. It is shown that the use of thin ferroelectric films for rapid capacitance variation versus temperature and microelectromechanical systems for fast temperature modulations may be a relevant solution for creation of small power scale generators for portable electronics.
Compression-induced stacking fault tetrahedra around He bubbles in Al
Authors: Shao Jian-Li , Wang Pei , He An-Min
Published: October 2014

Classic molecular dynamics methods are used to simulate the uniform compression process of the fcc Al containing He bubbles. The formation of stacking fault tetrahedra (SFTs) during the collapse of He bubbles is found, and their dependence on the initial He bubble size (0.6–6 nm in diameter) is presented. Our simulations indicate only elastic deformation in the samples for the He bubble size not more than 2 nm. Instead, increasing the He bubble size, we detect several small SFTs forming on the surface of the He bubble (3 nm), as well as the two intercrossed SFTs around the He bubbles (4–6 nm). All these SFTs are observed to be stable under further compression, though there may appear some SF networks outside the SFTs (5–6 nm). Furthermore, the dynamic analysis on the SFTs shows that the yield pressure keeps a near-linear increase with the initial He bubble pressure, and the potential energy of Al atoms inside the SFTs is lower than outside because of their gliding inwards. In addition, the pressure increments of 2–6 nm He bubbles with strain are less than that of Al, which just provides the opportunity for the He bubble collapse and the SFTs formation. Note that the current work only focuses on the case that the number ratio between He atoms and Al vacancies is 1:1.
Nanoscale three-dimensional reconstruction of electric and magnetic stray fields around nanowires
Authors: Lubk A. , Wolf D. , Simon P. , Wang C. , Sturm S. , Felser C.
Published: October 2014

Static electromagnetic stray fields around nanowires (NWs) are characteristic for a number of important physical effects such as field emission or magnetic force microscopy. Consequently, an accurate characterization of these fields is of high interest and electron holographic tomography (EHT) is unique in providing tomographic 3D reconstructions at nm spatial resolution. However, several limitations of the experimental setup and the specimen itself are influencing EHT. Here, we show how a deliberate restriction of the tomographic reconstruction to the exterior of the NWs can be used to mitigate these limitations facilitating a quantitative 3D tomographic reconstruction of static electromagnetic stray fields at the nanoscale. As an example, we reconstruct the electrostatic stray field around a GaAs-AlGaAs core shell NW and the magnetic stray field around a Co2FeGa Heusler compound NW.
Dielectric behavior of laminate-structure Cf/Si3N4 composites in X-band
Authors: Luo Heng , Xiao Peng , Hong Wen
Published: October 2014

Dielectric properties of laminate-structure Cf/Si3N4 composites as a function of frequency and surface density of short carbon fibers (SCFs) were studied. Results show that as the surface density of SCFs is up to 0.85 mg/cm2, an abrupt increase both in real and imaginary part of permittivity occurs. Taking conduction current into consideration, a revised Cole-Cole model of permittivity has proposed to reveal the mechanism of dielectric behavior. The best fitting results indicate that conduction loss played an important role in dielectric behavior of laminate-structure Cf/Si3N4 composites after percolation. Further more, the mean relaxation time is slightly smaller than characteristic relaxation time, which leads to continuous increase of the imaginary part of permittivity with frequency increased.
Direct electrical observation of plasma wave-related effects in GaN-based two-dimensional electron gases
Authors: Zhao Y. , Chen W. , Li W. , Zhu M. , Yue Y. , Song B. , Encomendero J. , Sensale-Rodriguez B. , Xing H. , Fay P.
Published: October 2014

In this work, signatures of plasma waves in GaN-based high electron mobility transistors were observed by direct electrical measurement at room temperature. Periodic grating-gate device structures were fabricated and characterized by on-wafer G-band (140–220 GHz) s-parameter measurements as a function of gate bias voltage and device geometry. A physics-based equivalent circuit model was used to assist in interpreting the measured s-parameters. The kinetic inductance extracted from the measurement data matches well with theoretical predictions, consistent with direct observation of plasma wave-related effects in GaN-channel devices at room temperature. This observation of electrically significant room-temperature plasma-wave effects in GaN-channel devices may have implications for future millimeter-wave and THz device concepts and designs.
Nonlinear transport in quasi-one-dimensional Nb2PdS5 nanowires
Authors: Ning Wei , Yu Hongyan , Wang Ning , Liu Yequn , Han Yuyan , Yang Jiyong , Du Haifeng , Zhang Changjin , Yang Kun , Tian Mingliang , Zhang Yuheng
Published: October 2014

Nb2PdS5 is a newly discovered quasi-one-dimensional (quasi-1D) superconductor with a high upper critical field along the chain direction. Here, we report the size-dependent electronic properties of Nb2PdS5 nanowires obtained by ultrasonically cleaving the bulk crystals. The nanowires exhibit a superconductor to insulator transition as the cross-sectional area decreases. Moreover, for the thinner nanowires with insulating state, the transport properties exhibit a power-law dependence on both temperature and bias voltage at an intermediate temperature (<30 K), followed by a conduction saturation below 10 K. We found that such an apparent power-law behavior can be described by the extended variable range hopping theory developed recently for the multichannel quasi-1D systems, where the localization of electrons is expected to be dominant instead of the Luttinger liquid nature.
Influence of maize particle size on the kinetics of starch digestion in the small intestine of growing pigs
Authors: Amaral N. O. , Amaral L. G. M. , Cantarelli V. S. , Fialho E. T. , Zangeronimo M. G. , Rodrigues P. B.
Published: October 2014

The kinetics of starch digestion in the small intestine, nutrient utilisation and the performance of growing pigs that were fed diets containing maize of different particle sizes were evaluated. For the performance evaluation, 42 barrows and females (initial weight: 30.5 ± 1.78 kg) were used in a randomised block design with three treatments [maize with different geometric mean diameters (GMD) of 550, 700 and 850 μm] and seven replications. To evaluate the kinetics of starch digestion, one animal from each experimental trial was sacrificed. The small intestine was removed and separated into five equal parts. The starch digestibility in each segment was determined. To determine the total digestibility and nitrogen balance, 24 barrows (initial weight: 41.3 ± 4.72 kg) were housed in metabolism cages in a randomised block design with three treatments and eight repetitions. The animals that were fed diets containing maize of 550-μm GMD exhibited better (P = 0.008) feed conversion. However, the digestion of starch was gradual and variable among the degrees of grinding that were tested. There were higher (P = 0.008; 0.005 and 0.009) digestible energy, dry matter digestibility and nitrogen uptake in diets containing the maize ground to 550 and 700 μm in GMD. Thus, the smallest GMD of maize (550 μm) that was used in diets for growing pigs improves feed conversion. GMD of 550, 700 and 850 μm of maize were associated with rapid, intermediate and slow starch digestion, respectively.
Aberrant expression of TAR DNA binding protein-43 is associated with spermatogenic disorders in men
Authors: Varghese Divya Saro , Chandran Uma , Soumya Ambili , Pillai Sathy M. , Jayakrishnan Krishnapillai , Reddi Prabhakara P. , Kumar Pradeep G.
Published: October 2014

Loss of function of TAR DNA-binding protein (TDP-43) has been implicated in neurodegenerative disorders in both humans and animal models. TDP-43 has also been shown to be cis-acting transcriptional repressor of the acrosome vesicle (Acrv) gene in mice. In the present study, we investigated the expression of the TDP-43 transcript (TARDBP) and protein in germ cells from 11 fertile and 98 subfertile men to verify its potential association with poor seminograms. The expression profile of TDP-43 was characterised in immature germ cells and spermatozoa from semen from fertile and subfertile men using reverse transcription–polymerase chain reaction, western blotting and immunofluorescence. Although germ cells from subfertile men tested negative for TARDBP, the full-length message of the same was detected in fertile men. TDP-43 was detected in spermatozoa from fertile men using western blot analysis and immunofluorescence. The expression of this protein was negligible in spermatozoa from men with primary spermatogenic dysfunction. We conclude that a deficiency in the TDP-43 expression is associated with defective spermatogenesis and male infertility. We propose that TDP-43 could be used as a marker of male factor infertility.
Aquaporins 7 and 11 in boar spermatozoa: detection, localisation and relationship with sperm quality
Authors: Prieto-Martínez Noelia , Vilagran Ingrid , Morató Roser , Rodríguez-Gil Joan E. , Yeste Marc , Bonet Sergi
Published: October 2014

Aquaporins (AQPs) are integral membrane water channels that allow transport of water and small solutes across cell membranes. Although water permeability is known to play a critical role in mammalian cells, including spermatozoa, little is known about their localisation in boar spermatozoa. Two aquaporins, AQP7 and AQP11, in boar spermatozoa were identified by western blotting and localised through immunocytochemistry analyses. Western blot results showed that boar spermatozoa expressed AQP7 (25 kDa) and AQP11 (50 kDa). Immunocytochemistry analyses demonstrated that AQP7 was localised in the connecting piece of boar spermatozoa, while AQP11 was found in the head and mid-piece and diffuse labelling was also seen along the tail. Despite differences in AQP7 and AQP11 content between boar ejaculates, these differences were not found to be correlated with sperm quality in the case of AQP7. Conversely, AQP11 content showed a significant correlation (P < 0.05) with sperm membrane integrity and fluidity and sperm motility. In conclusion, boar spermatozoa express AQP7 and AQP11, and the amounts of AQP11 but not those of AQP7 are correlated with sperm motility and membrane integrity.
Bap1
is essential for kidney function and cooperates with
Vhl
in renal tumorigenesis
Authors: Wang Shan-Shan , Gu Yi-Feng , Wolff Nicholas , Stefanius Karoliina , Christie Alana , Dey Anwesha , Hammer Robert E. , Xie Xian-Jin , Rakheja Dinesh , Pedrosa Ivan , Carroll Thomas , McKay Renée M. , Kapur Payal , Brugarolas James
Published: October 2014

Significance

Despite the discovery of the von Hippel–Lindau (
VHL
) gene in 1993, and that inactivating germ-line mutations of
VHL
cause multiple kidney lesions, including clear-cell renal cell carcinoma (ccRCC),
Vhl
inactivation in the mouse does not lead to ccRCC and a mouse model has been lacking. We discovered that the BRCA1-associated protein-1 (
BAP1
) two-hit tumor suppressor gene is mutated in ccRCC, and one
BAP1
allele is frequently somatically codeleted with
VHL
in tumors. In the mouse,
Vhl
and
Bap1
are on different chromosomes. We show that SIX homeobox 2 (
Six2
)
-Cre;Vhl

F/F

;Bap1

F/
+

mice develop premalignant lesions and malignant ccRCC resembling VHL syndrome. More broadly, differences in tumor predisposition across species may result from differences in the location of two-hit tumor suppressor genes across the genome.