bluuebunny/crossref_metadata_2025 huggingface dataset:
VirB8-like protein TraH is crucial for DNA transfer in Enterococcus faecalis
Authors: Fercher Christian , Probst Ines , Kohler Verena , Goessweiner-Mohr Nikolaus , Arends Karsten , Grohmann Elisabeth , Zangger Klaus , Meyer N. Helge , Keller Walter
Published: April 2016

Untreatable bacterial infections caused by a perpetual increase of antibiotic resistant strains represent a serious threat to human healthcare in the 21st century. Conjugative DNA transfer is the most important mechanism for antibiotic resistance and virulence gene dissemination among bacteria and is mediated by a protein complex, known as type IV secretion system (T4SS). The core of the T4SS is a multiprotein complex that spans the bacterial envelope as a channel for macromolecular secretion. We report the NMR structure and functional characterization of the transfer protein TraH encoded by the conjugative Gram-positive broad-host range plasmid pIP501. The structure exhibits a striking similarity to VirB8 proteins of Gram-negative secretion systems where they play an essential role in the scaffold of the secretion machinery. Considering TraM as the first VirB8-like protein discovered in pIP501, TraH represents the second protein affiliated with this family in the respective transfer operon. A markerless traH deletion in pIP501 resulted in a total loss of transfer in Enterococcus faecalis as compared with the pIP501 wild type (wt) plasmid, demonstrating that TraH is essential for pIP501 mediated conjugation. Moreover, oligomerization state and topology of TraH in the native membrane were determined providing insights in molecular organization of a Gram-positive T4SS.
Three-Dimensional Super-Resolution Morphology by Near-Field Assisted White-Light Interferometry
Authors: Wang Feifei , Liu Lianqing , Yu Peng , Liu Zhu , Yu Haibo , Wang Yuechao , Li Wen Jung
Published: April 2016

Recent developments in far-field fluorescent microscopy have enabled nanoscale imaging of biological entities by ingenious applications of fluorescent probes. For non-fluorescence applications, however, scanning probe microscopy still remains one of the most commonly used methods to “image” nanoscale features in all three dimensions, despite its limited throughput and invasiveness to scanned samples. Here, we propose a time-efficient three-dimensional super-resolution microscopy method: near-field assisted white light interferometry (NFWLI). This method takes advantage of topography acquisition using white-light interferometry and lateral near-field imaging via a microsphere superlens. The ability to discern structures in central processing units (CPUs) with minimum feature sizes of approximately 50 nm in the lateral dimensions and approximately 10 nm in the axial dimension within 25 s (40 times faster than atomic force microscopes) was demonstrated. We elaborate in this paper the principles of NFWLI and demonstrate its potential for becoming a practical method for high-speed and non-toxic three-dimensional nanoscale imaging.
Gene expression of Lactobacillus plantarum and the commensal microbiota in the ileum of healthy and early SIV-infected rhesus macaques
Authors: Golomb Benjamin L. , Hirao Lauren A. , Dandekar Satya , Marco Maria L.
Published: April 2016

Chronic HIV infection results in impairment of gut-associated lymphoid tissue leading to systemic immune activation. We previously showed that in early SIV-infected rhesus macaques intestinal dysfunction is initiated with the induction of the IL-1β pathway in the small intestine and reversed by treatment with an exogenous Lactobacillus plantarum strain. Here, we provide evidence that the transcriptomes of L. plantarum and ileal microbiota are not altered shortly after SIV infection. L. plantarum adapts to the small intestine by expressing genes required for tolerating oxidative stress, modifying cell surface composition and consumption of host glycans. The ileal microbiota of L. plantarum-containing healthy and SIV+ rhesus macaques also transcribed genes for host glycan metabolism as well as for cobalamin biosynthesis. Expression of these pathways by bacteria were proposed but not previously demonstrated in the mammalian small intestine.
Infection pattern and transmission potential of chikungunya virus in two New World laboratory-adapted Aedes aegypti strains
Authors: Dong Shengzhang , Kantor Asher M. , Lin Jingyi , Passarelli A. Lorena , Clem Rollie J. , Franz Alexander W. E.
Published: April 2016

Chikungunya virus (CHIKV) is an emerging mosquito-borne virus belonging to the Togaviridae, which is transmitted to humans by Aedes aegypti and Ae. albopictus. We describe the infection pattern of CHIKV in two New World Ae. aegypti strains, HWE and ORL. Both mosquito strains were susceptible to the virus but showed different infection patterns in midguts and salivary glands. Even though acquisition of a bloodmeal showed moderate levels of apoptosis in midgut tissue, there was no obvious additional CHIKV-induced apoptosis detectable during midgut infection. Analysis of expression of apoptosis-related genes suggested that CHIKV infection dampens rather than promotes apoptosis in the mosquito midgut. In both mosquito strains, the virus was present in saliva within two days post-oral infection. HWE and ORL mosquitoes exhibited no salivary gland infection barrier; however, only 60% (HWE) to 65% (ORL) of the females had released the virus in their saliva at one week post-oral acquisition, suggesting a salivary gland escape barrier. CHIKV induced an apoptotic response in salivary glands of HWE and ORL mosquitoes, demonstrating that the virus caused pathology in its natural vector.
Global antibody response to Staphylococcus aureus live-cell vaccination
Authors: Selle Martina , Hertlein Tobias , Oesterreich Babett , Klemm Theresa , Kloppot Peggy , Müller Elke , Ehricht Ralf , Stentzel Sebastian , Bröker Barbara M. , Engelmann Susanne , Ohlsen Knut
Published: April 2016

The pathogen Staphylococcus aureus causes a broad range of severe diseases and is feared for its ability to rapidly develop resistance to antibiotic substances. The increasing number of highly resistant S. aureus infections has accelerated the search for alternative treatment options to close the widening gap in anti-S. aureus therapy. This study analyses the humoral immune response to vaccination of Balb/c mice with sublethal doses of live S. aureus. The elicited antibody pattern in the sera of intravenously and intramuscularly vaccinated mice was determined using of a recently developed protein array. We observed a specific antibody response against a broad set of S. aureus antigens which was stronger following i.v. than i.m. vaccination. Intravenous but not intramuscular vaccination protected mice against an intramuscular challenge infection with a high bacterial dose. Vaccine protection was correlated with the strength of the anti-S. aureus antibody response. This study identified novel vaccine candidates by using protein microarrays as an effective tool and showed that successful vaccination against S. aureus relies on the optimal route of administration.
Structural basis for the specific inhibition of glycoprotein Ibα shedding by an inhibitory antibody
Authors: Tao Yue , Zhang Xiaoqin , Liang Xin , Zang Jianye , Mo Xi , Li Renhao
Published: April 2016

Ectodomain shedding of glycoprotein (GP) Ibα is thought to mediate the clearance of activated, aged or damaged platelets. A monoclonal antibody, 5G6, has been developed recently to specifically bind to the GPIbα shedding cleavage site and to inhibit its shedding. However, the molecular mechanism underlying antigen recognition and inhibitory specificity is not clear. To elucidate the structural basis for 5G6 binding to GPIbα, we determined the crystal structure of 5G6 Fab fragment in complex with its epitope peptide KL10 (GPIbα residues 461–470, KLRGVLQGHL), to 2.4-Å resolution. Key residues in both 5G6 and KL10 were mutated to validate their effects in antibody binding by using isothermal titration calorimetry. The 5G6 Fab-KL10 peptide complex structure confirmed the direct association of 5G6 with its target GPIbα residues and elucidated the molecular basis underlying its binding specificity and high affinity. The similar binding properties of 5G6 Fab fragment to GPIbα on human platelets as those to KL10 suggests that such an interaction may not be affected by the plasma membrane or nearby GPIbβ. This structural information may facilitate further antibody optimization and humanization.
Prolonged sleep restriction induces changes in pathways involved in cholesterol metabolism and inflammatory responses
Authors: Aho Vilma , Ollila Hanna M. , Kronholm Erkki , Bondia-Pons Isabel , Soininen Pasi , Kangas Antti J. , Hilvo Mika , Seppälä Ilkka , Kettunen Johannes , Oikonen Mervi , Raitoharju Emma , Hyötyläinen Tuulia , Kähönen Mika , Viikari Jorma S.A. , Härmä Mikko , Sallinen Mikael , Olkkonen Vesa M. , Alenius Harri , Jauhiainen Matti , Paunio Tiina , Lehtimäki Terho , Salomaa Veikko , Orešič Matej , Raitakari Olli T. , Ala-Korpela Mika , Porkka-Heiskanen Tarja
Published: April 2016

Sleep loss and insufficient sleep are risk factors for cardiometabolic diseases, but data on how insufficient sleep contributes to these diseases are scarce. These questions were addressed using two approaches: an experimental, partial sleep restriction study (14 cases and 7 control subjects) with objective verification of sleep amount, and two independent epidemiological cohorts (altogether 2739 individuals) with questions of sleep insufficiency. In both approaches, blood transcriptome and serum metabolome were analysed. Sleep loss decreased the expression of genes encoding cholesterol transporters and increased expression in pathways involved in inflammatory responses in both paradigms. Metabolomic analyses revealed lower circulating large HDL in the population cohorts among subjects reporting insufficient sleep, while circulating LDL decreased in the experimental sleep restriction study. These findings suggest that prolonged sleep deprivation modifies inflammatory and cholesterol pathways at the level of gene expression and serum lipoproteins, inducing changes toward potentially higher risk for cardiometabolic diseases.
Exact comprehensive equations for the photon management properties of silicon nanowire
Authors: Li Yingfeng , Li Meicheng , Li Ruike , Fu Pengfei , Wang Tai , Luo Younan , Mbengue Joseph Michel , Trevor Mwenya
Published: April 2016

Unique photon management (PM) properties of silicon nanowire (SiNW) make it an attractive building block for a host of nanowire photonic devices including photodetectors, chemical and gas sensors, waveguides, optical switches, solar cells, and lasers. However, the lack of efficient equations for the quantitative estimation of the SiNW’s PM properties limits the rational design of such devices. Herein, we establish comprehensive equations to evaluate several important performance features for the PM properties of SiNW, based on theoretical simulations. Firstly, the relationships between the resonant wavelengths (RW), where SiNW can harvest light most effectively, and the size of SiNW are formulized. Then, equations for the light-harvesting efficiency at RW, which determines the single-frequency performance limit of SiNW-based photonic devices, are established. Finally, equations for the light-harvesting efficiency of SiNW in full-spectrum, which are of great significance in photovoltaics, are established. Furthermore, using these equations, we have derived four extra formulas to estimate the optimal size of SiNW in light-harvesting. These equations can reproduce majority of the reported experimental and theoretical results with only ~5% error deviations. Our study fills up a gap in quantitatively predicting the SiNW’s PM properties, which will contribute significantly to its practical applications.
Soluble VEGF receptor 1 (sFLT1) induces non-apoptotic death in ovarian and colorectal cancer cells
Authors: Miyake Tatsuya , Kumasawa Keiichi , Sato Noriko , Takiuchi Tsuyoshi , Nakamura Hitomi , Kimura Tadashi
Published: April 2016

Soluble Vascular Endothelial Growth Factor Receptor 1 (sVEGFR1/sFLT1) is an angiogenesis inhibitor that competes with angiogenic factors such as VEGF and Placental Growth Factor (PlGF). Imbalances of VEGF and sFLT1 levels can cause pathological conditions such as tumour growth or preeclampsia. We observed direct damage caused by sFLT1 in tumour cells. We exposed several kinds of cells derived from ovarian and colorectal cancers as well as HEK293T cells to sFLT1 in two ways, transfection and exogenous application. The cell morphology and an LDH assay revealed cytotoxicity. Additional experiments were performed to clarify how sFLT1 injured cells. In this study, non-apoptotic cell damage was found to be induced by sFLT1. Moreover, sFLT1 showed an anti-tumour effect in a mouse model of ovarian cancer. Our results suggest that sFLT1 has potential as a cancer therapeutic candidate.
Response of tomato wilt pathogen Ralstonia solanacearum to the volatile organic compounds produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9
Authors: Raza Waseem , Ling Ning , Yang Liudong , Huang Qiwei , Shen Qirong
Published: April 2016

It is important to study the response of plant pathogens to the antibiosis traits of biocontrol microbes to design the efficient biocontrol strategies. In this study, we evaluated the role of volatile organic compounds (VOCs) produced by a biocontrol strain Bacillus amyloliquefaciens SQR-9 on the growth and virulence traits of tomato wilt pathogen Ralstonia solanacearum (RS). The VOCs of SQR-9 significantly inhibited the growth of RS on agar medium and in soil. In addition, the VOCs significantly inhibited the motility traits, production of antioxidant enzymes and exopolysaccharides, biofilm formation and tomato root colonization by RS. The strain SQR-9 produced 22 VOCs, but only nine VOCs showed 1–11% antibacterial activity against RS in their corresponding amounts; however, the consortium of all VOCs showed 70% growth inhibition of RS. The proteomics analysis showed that the VOCs of SQR-9 downregulated RS proteins related to the antioxidant activity, virulence, carbohydrate and amino acid metabolism, protein folding and translation, while the proteins involved in the ABC transporter system, amino acid synthesis, detoxification of aldehydes and ketones, methylation, protein translation and folding, and energy transfer were upregulated. This study describes the significance and effectiveness of VOCs produced by a biocontrol strain against tomato wilt pathogen.
Microwave-assisted Facile and Ultrafast Growth of ZnO Nanostructures and Proposition of Alternative Microwave-assisted Methods to Address Growth Stoppage
Authors: Rana Abu ul Hassan Sarwar , Kang Mingi , Kim Hyun-Seok
Published: April 2016

The time constraint in the growth of ZnO nanostructures when using a hydrothermal method is of paramount importance in contemporary research, where a long fabrication time rots the very essence of the research on ZnO nanostructures. In this study, we present the facile and ultrafast growth of ZnO nanostructures in a domestic microwave oven within a pressurized environment in just a few minutes. This method is preferred for the conventional solution-based method because of the ultrafast supersaturation of zinc salts and the fabrication of high-quality nanostructures. The study of the effect of seed layer density, growth time, and the solution’s molar concentration on the morphology, alignment, density, and aspect ratio of ZnO nanorods (ZNRs) is explored. It is found in a microwave-assisted direct growth method that ~5 mins is the optimum time beyond which homogeneous nucleation supersedes heterogeneous nucleation, which results in the growth stoppage of ZNRs. To deal with this issue, we propound different methods such as microwave-assisted solution-replacement, preheating, and PEI-based growth methods, where growth stoppage is addressed and ZNRs with a high aspect ratio can be grown. Furthermore, high-quality ZnO nanoflowers and ZnO nanowalls are fabricated via ammonium hydroxide treatment in a very short time.
Negative incidental emotions augment fairness sensitivity
Authors: Liu Cuizhen , Chai Jing Wen , Yu Rongjun
Published: April 2016

Previous studies have shown that task-unrelated emotions induced incidentally exert carryover effects on individuals’ subsequent decisions in financial negotiations. However, the specificity of these emotion effects are not clear. In three experiments, we systematically investigated the role of seven transiently induced basic emotions (disgust, sadness, anger, fear, happiness, surprise and neutral) on rejection of unfair offers using the ultimatum game. We found that all negative emotions (disgust, sadness, anger and fear), but not happiness or surprise, significantly increased rejection rates, suggesting that the effect of incidental negative emotions on fairness is not specific to the type of negative emotion. Our findings highlight the role of fleeting emotions in biasing decision-making processes and suggest that all incidental negative emotions exert similar effects on fairness sensitivity, possibly by potentiating attention towards negative aspects of the situation.
The sporulation of the green alga Ulva prolifera is controlled by changes in photosynthetic electron transport chain
Authors: Wang Hui , Lin Apeng , Gu Wenhui , Huan Li , Gao Shan , Wang Guangce
Published: April 2016

Sporulation and spore release are essential phases of the life cycle in algae and land plants. Ulva prolifera, which is an ideal organism for studying sporulation and spore release, was used as the experimental material in the present study. The determination of photosynthetic parameters, combined with microscopic observation, treatment with photosynthetic inhibitors, limitation of carbon acquisition, and protein mass spectrometry, was employed in this experiment. Cycle electron transport (CEF) was found enhanced at the onset of sporangia formation. The inhibition effect of dibromothymoquinone (DBMIB) towards sporulation was always strong during the sporulation process whereas the inhibition effect of 3-(3′,4′-dichlorophenyl)-1,1-dimethylurea (DCMU) was continuously declined accompanied with the progress of sporulation. The changes of photosynthesis resulted from the limitation of CO2 acquisition could stimulate sporulation onset. Quantitative protein analysis showed that enzymes involved in carbon fixation, including RUBISCO and pyruvate orthophosphate dikinase, declined during sporogenesis, while proteins involved in sporulation, including tubulin and centrin, increased. These results suggest that enhanced cyclic electron flow (CEF) and oxidation of the plastoquinone pool are essential for sporangia formation onset, and changes in photosynthetic electron transport chain have significant impacts on sporulation of the green algae.
Dietary proanthocyanidins boost hepatic NAD+ metabolism and SIRT1 expression and activity in a dose-dependent manner in healthy rats
Authors: Aragonès Gerard , Suárez Manuel , Ardid-Ruiz Andrea , Vinaixa Maria , Rodríguez Miguel A. , Correig Xavier , Arola Lluís , Bladé Cinta
Published: April 2016

Proanthocyanidins (PACs) have been reported to modulate multiple targets by simultaneously controlling many pivotal metabolic pathways in the liver. However, the precise mechanism of PAC action on the regulation of the genes that control hepatic metabolism remains to be clarified. Accordingly, we used a metabolomic approach combining both nuclear magnetic resonance and mass spectrometry analysis to evaluate the changes induced by different doses of grape-seed PACs in the liver of healthy rats. Here, we report that PACs significantly increased the hepatic nicotinamide adenine dinucleotide (NAD+) content in a dose-dependent manner by specifically modulating the hepatic concentrations of the major NAD+ precursors as well as the mRNA levels of the genes that encode the enzymes involved in the cellular metabolism of NAD+. Notably, Sirtuin 1 (Sirt1) gene expression was also significantly up-regulated in a dose-response pattern. The increase in both the NAD+ availability and Sirt1 mRNA levels, in turn, resulted in the hepatic activation of SIRT1, which was significantly associated with improved protection against hepatic triglyceride accumulation. Our data clearly indicates that PAC consumption could be a valid tool to enhance hepatic SIRT1 activity through the modulation of NAD+ levels.
Dissociative ionization of the 1-propanol dimer in a supersonic expansion under tunable synchrotron VUV radiation
Authors: Tao Yanmin , Hu Yongjun , Xiao Weizhan , Guan Jiwen , Liu Fuyi , Shan Xiaobin , Sheng Liusi
Published: April 2016

Different C–C bond cleavage of the 1-propanol dimer induced by site-selective photoionization under tunable synchrotron VUV radiation.
A new dipstick colorimetric sensor for detection of arsenate in drinking water
Authors: Das Joyati , Sarkar Priyabrata
Published: April 2016

The first ever dipstick sensing of arsenate through visual observation without any instrumentation.
Antimalarial activity of novel 4-cyano-3-methylisoquinoline inhibitors against Plasmodium falciparum: design, synthesis and biological evaluation
Authors: Buskes Melissa J. , Harvey Katherine L. , Richards Benjamin J. , Kalhor Robabeh , Christoff Rebecca M. , Gardhi Chamodi K. , Littler Dene R. , Cope Elliott D. , Prinz Boris , Weiss Greta E. , O'Brien Nathan J. , Crabb Brendan S. , Deady Leslie W. , Gilson Paul R. , Abbott Belinda M.
Published: April 2016

A series of 4-cyano-3-methylisoquinolines have been shown to inhibit parasite cytokinesis and erythrocyte invasion.
3D hierarchical CuO mesocrystals from ionic liquid precursors: towards better electrochemical performance for Li-ion batteries
Authors: Duan Xiaochuan , Huang Hui , Xiao Songhua , Deng Jiwei , Zhou Gang , Li Qiuhong , Wang Taihong
Published: April 2016

3D hierarchical CuO mesocrystals have been prepared from ionic liquid precursors under hydrothermal conditions, and exhibited superior electrochemical performance as anode materials, which offers a facile route for designing high-performance electrodes for Li-ion batteries.
Startling temperature effect on proteins when confined: single molecular level behaviour of human serum albumin in a reverse micelle
Authors: Sengupta Bhaswati , Yadav Rajeev , Sen Pratik
Published: April 2016

The present work reports the effect of confinement, and temperature therein, on the conformational fluctuation dynamics of domain-I of human serum albumin (HSA) by fluorescence correlation spectroscopy (FCS).
Hydrogen bond cooperativity and anticooperativity within the water hexamer
Authors: Guevara-Vela José Manuel , Romero-Montalvo Eduardo , Mora Gómez Víctor Arturo , Chávez-Calvillo Rodrigo , García-Revilla Marco , Francisco Evelio , Pendás Ángel Martín , Rocha-Rinza Tomás
Published: April 2016

We propose a hierarchy of H-bond strength in terms of the single and double character of the involved donor and acceptors within different structures of (H2O)6.
New insight into probe-location dependent polarity and hydration at lipid/water interfaces: comparison between gel- and fluid-phases of lipid bilayers
Authors: Singh Moirangthem Kiran , Shweta Him , Khan Mohammad Firoz , Sen Sobhan
Published: April 2016

Location dependent polarity and hydration probed by a new series of 4-aminophthalimide-based fluorescent molecules (4AP-Cn;n= 2–10, 12) show different behaviour at gel- and fluid-phase lipid/water interfaces.
Investigation of the electrochemical and photoelectrochemical properties of Ni–Al LDH photocatalysts
Authors: Iguchi Shoji , Kikkawa Soichi , Teramura Kentaro , Hosokawa Saburo , Tanaka Tsunehiro
Published: April 2016

Layered double hydroxide (LDH) photocatalysts, including Ni–Al LDH, are active for the photocatalytic conversion of CO2 in water under UV light irradiation.
The importance of heat effects in the methanol to hydrocarbons reaction over ZSM-5: on the role of mesoporosity on catalyst performance
Authors: Yarulina Irina , Kapteijn Freek , Gascon Jorge
Published: April 2016

Interpretation of catalytic performance during the MTH process is hampered by heat transport phenomena.
Design and synthesis of fused soluble epoxide hydrolase/peroxisome proliferator-activated receptor modulators
Authors: Blöcher R. , Lamers C. , Wittmann S. K. , Diehl O. , Hanke T. , Merk D. , Steinhilber D. , Schubert-Zsilavecz M. , Kahnt A. S. , Proschak E.
Published: April 2016

Metabolic syndrome (MetS) is a widespread, complex disease cluster which consists of hypertension, atherosclerosis, dyslipidaemia and type II diabetes.
Copper catalyzed oxidative deamination of Betti bases: an efficient approach for benzoylation/formylation of naphthols and phenols
Authors: Deb Mohit L. , Pegu Choitanya Dev , Borpatra Paran J. , Baruah Pranjal K.
Published: April 2016

A copper-catalyzed benzoylation/formylation of naphthols and phenolsviaoxidative deamination of Betti bases.
Improved cell infiltration and vascularization of three-dimensional bacterial cellulose nanofibrous scaffolds by template biosynthesis
Authors: Li Zhe , Lv Xiangguo , Chen Shiyan , Wang Baoxiu , Feng Chao , Xu Yuemin , Wang Huaping
Published: April 2016

A significant problem limiting the application of bacterial cellulose (BC) nanofibrous scaffolds for tissue regeneration is the nanoscale pores that inhibit cell infiltration and vascularization in their three-dimensional (3D) structure.
Synthesis and properties of optically active helical polymers from (S)-3-functional-3′-vinyl-BINOL derivatives
Authors: Zhao Chunhui , Ouyang Kunbing , Zhang Jin , Yang Nianfa
Published: April 2016

Helical vinyl polymers bearing N-heterocycles substituent BINOL derivatives were synthesized. The specific optical rotation and circular dichroism spectra data show the obtained polymers can keep a prevailing helicity of backbone in solution.
Hard‐decision iterative decoder for the Davey–MacKay construction with symbol‐level inner decoder
Authors: Liu Yuan , Chen Weigang
Published: April 2016

A hard‐decision iterative decoding scheme for the Davey–MacKay construction with symbol‐level inner decoder is presented. In this scheme, the synchronisation capability of the inner decoder is enhanced by replacing the equal priori probabilities for symbols by the accurate hard‐decision feedback information from the outer decoder. Furthermore, the error‐correcting capability of the outer decoder is improved and the hard‐decision feedback information is updated. Simulation results show that the presented scheme significantly improves the performance and saves the computational time with little performance loss.
Quantitative broken rotor bar fault detection for closed‐loop controlled induction motors
Authors: Hou Zhaowen , Huang Jin , Liu He , Wang Tong , Zhao Lihang
Published: April 2016

In an induction motor with broken rotor bars, stator currents contain fault‐related components. The fault information propagates to voltages when the motor is in a closed‐loop control. The control has an effect on the currents and voltages. Relying solely on the currents or voltages is difficult to obtain an accurate detection and quantification of the fault. A new online diagnosis method, which takes both currents and voltages into consideration, is proposed in this study. A fault severity factor is proposed to evaluate the extension of the fault, which is almost independent of the control parameters. Furthermore, the method can be applied to different control strategies. The effectiveness and robustness of the proposed method have been validated by experimental results.
Insights into prior learning for despeckling SAR images
Authors: Xu Zhi‐huo , Deng Yun‐kai , Wang Robert
Published: April 2016

This study presents an exploratory comparative study for learning the priors of synthetic aperture radar (SAR) images, using the Fields of Experts approach, a filter‐based higher‐order Markov random fields model, which has substantially improved the learning capability of the entire image priors. First, the authors provide new insights into prior learning for despeckling SAR images, which commonly exhibits a variety of the likelihood functions due to the complex physical process of the scattering. Second, the authors introduce a prior learning framework using a bi‐level optimisation algorithm. Third, some interesting experiments are conducted to learn the priors of SAR images. Finally, the authors validate the learned priors on despeckling SAR images. It suggests that the representation of the prior is more accurate by using the training samples from the filtered real SAR images themselves than from both the optical images of the Earth's surface and the natural images.
Spinal Compression Fracture Management
Authors: Genev Ivo K. , Tobin Matthew K. , Zaidi Saher P. , Khan Sajeel R. , Amirouche Farid M. L. , Mehta Ankit I.
Published: April 2016

Study Design

Narrative review.

Objective

Despite the numerous treatment options for vertebral compression fractures, a consensus opinion for the management of patients with these factures has not been established. This review is meant to provide an up-to-date overview of the most common treatment strategies for compression fractures and to suggest possible routes for the development of clearer treatment guidelines.

Methods

A comprehensive database search of PubMed was performed. All results from the past 30 years were obtained and evaluated based on title and abstract. The full length of relevant studies was analyzed for level of evidence, and the strongest studies were used in this review.

Results

The major treatment strategies for patients with compression fractures are conservative pain management and vertebral augmentation. Despite potential adverse effects, medical management, including nonsteroidal anti-inflammatory drugs, calcitonin, teriparatide, and bisphosphonates, remains the first-line therapy for patients. Evidence suggests that vertebral augmentation, especially some of the newer procedures, have the potential to dramatically reduce pain and improve quality of life. At this time, balloon-assisted kyphoplasty is the procedure with the most evidence of support.

Conclusions

Based on current literature, it is evident that there is a lack of standard of care for patients with vertebral compression fractures, which is either due to lack of evidence that a procedure is successful or due to serious adverse effects encountered with prolonged treatment. For a consensus to be reached, prospective clinical trials need to be formulated with potential new biomarkers to assess efficacy of treatment strategies.
Inanspruchnahme zentraler Notaufnahmen: Qualitative Erhebung der Motivation von Patientinnen und Patienten mit nichtdringlichem Behandlungsbedarf
Authors: Schmiedhofer M. , Searle J. , Slagman A. , Möckel M.
Published: April 2016

Einleitung: Die steigende Inanspruchnahme von Zentralen Notaufnahmen (ZNA) durch Patientinnen und Patienten mit akut-, aber nicht notfallmedizinischem Versorgungsbedarf trägt zur Überfüllung der Notaufnahmen bei. Ziel dieser Arbeit ist die Exploration der subjektiven Motive zum Aufsuchen der ZNA durch Menschen mit nichtdringlichem Behandlungsbedarf.

Methode: In einer qualitativen Studie wurden 40 leitfadengestützte Interviews mit ambulanten Patientinnen und Patienten ohne dringlichen Handlungsbedarf an 2 ZNA der Charité Berlin durchgeführt und mit der Qualitativen Inhaltsanalyse ausgewertet.

Ergebnis: Neben der Substitution nicht oder spät verfügbarer Haus- oder Facharzttermine gaben die Befragten als Hauptmotive Zeitautonomie, den Qualitätsstandard eines universitären Krankenhauses sowie die Möglichkeit multidisziplinärer Untersuchungen während eines Termins an. Die Bemühungen um eine Terminfindung im ambulanten Bereich erschienen durch die allzeitige Verfügbarkeit der ZNA teilweise wenig konsequent.

Schlussfolgerung: Die Interviewdaten zeigen eine eigenständige Funktion der ZNA für ambulante Behandlungen auf. Es ist anzunehmen, dass auch eine konsequentere Wahrnehmung des Sicherstellungsauftrages der KV die Anforderungen an die ZNA nicht auf die Versorgung medizinischer Notfälle zurückführen könnte. Zur dauerhaften Sicherstellung der medizinischen Qualität für Patientinnen und Patienten aller Dringlichkeitsstufen ist eine den Anforderungen entsprechende Ausstattung der ZNA erforderlich.
Multistability in Chua's circuit with two stable node-foci
Authors: Bao B. C. , Li Q. D. , Wang N. , Xu Q.
Published: April 2016

Only using one-stage op-amp based negative impedance converter realization, a simplified Chua's diode with positive outer segment slope is introduced, based on which an improved Chua's circuit realization with more simpler circuit structure is designed. The improved Chua's circuit has identical mathematical model but completely different nonlinearity to the classical Chua's circuit, from which multiple attractors including coexisting point attractors, limit cycle, double-scroll chaotic attractor, or coexisting chaotic spiral attractors are numerically simulated and experimentally captured. Furthermore, with dimensionless Chua's equations, the dynamical properties of the Chua's system are studied including equilibrium and stability, phase portrait, bifurcation diagram, Lyapunov exponent spectrum, and attraction basin. The results indicate that the system has two symmetric stable nonzero node-foci in global adjusting parameter regions and exhibits the unusual and striking dynamical behavior of multiple attractors with multistability.
Reducing extrinsic damping of surface acoustic waves at gigahertz frequencies
Authors: Gelda Dhruv , Sadhu Jyothi , Ghossoub Marc G. , Ertekin Elif , Sinha Sanjiv
Published: April 2016

High-frequency surface acoustic waves (SAWs) in the gigahertz range can be generated using absorption from an ultrafast laser in a patterned metallic grating on a substrate. Reducing the attenuation at these frequencies can yield better sensors as well as enable them to better probe phonon and electron-phonon interactions near surfaces. It is not clear from existing experiments which mechanisms dominate damping at high frequencies. We calculate damping times of SAWs due to various mechanisms in the 1–100 GHz range to find that mechanical loading of the grating on the substrate dominates dissipation by radiating energy from the surface into the bulk. To overcome this and enable future measurements to probe intrinsic damping, we propose incorporating distributed acoustic Bragg reflectors in the experimental structure. Layers of alternating materials with contrasting acoustic impedances embedded a wavelength away from the surface serve to reflect energy back to the surface. Using numerical simulations, we show that a single Bragg reflector is sufficient to increase the energy density at the surface by more than five times. We quantify the resulting damping time to find that it is longer than the intrinsic damping time. The proposed structure can enable future measurements of intrinsic damping in SAWs at ∼100 GHz.
Molecular dynamics simulations of void coalescence in monocrystalline copper under loading and unloading
Authors: Peng Xiaojuan , Zhu Wenjun , Chen Kaiguo , Deng Xiaoliang , Wei Yongkai
Published: April 2016

Molecular dynamic calculations are used to examine the anisotropy of voids coalescence under loading and unloading conditions in monocrystalline coppers. In this paper, three typical orientations are investigated, including [100], [110], and [111]. The study shows that voids collapse after the shock loading, leaving two disordered regions at the initial voids sites. Voids re-nucleate in the disordered regions and grow by the emission of dislocations on various slip planes. The dislocation motion contributes to local stress relaxation, which causes the voids to expand to certain radius and then coalesce with each other by dislocation emission. Due to the influence of the anisotropy shear field and different slip systems around the voids, the dislocations emit more easily at specific position, which lead to the anisotropy of void coalescence. A two-dimensional analysis model based on a shear dislocation is proposed and it explains the phenomena of void coalescence in the simulations quite well.
Water anomalous thermodynamics, attraction, repulsion, and hydrophobic hydration
Authors: Cerdeiriña Claudio A. , Debenedetti Pablo G.
Published: April 2016

A model composed of van der Waals-like and hydrogen bonding contributions that simulates the low-temperature anomalous thermodynamics of pure water while exhibiting a second, liquid-liquid critical point [P. H. Poole et al., Phys. Rev. Lett. 73, 1632 (1994)] is extended to dilute solutions of nonionic species. Critical lines emanating from such second critical point are calculated. While one infers that the smallness of the water molecule may be a relevant factor for those critical lines to move towards experimentally accessible regions, attention is mainly focused on the picture our model draws for the hydration thermodynamics of purely hydrophobic and amphiphilic non-electrolyte solutes. We first focus on differentiating solvation at constant volume from the corresponding isobaric process. Both processes provide the same viewpoint for the low solubility of hydrophobic solutes: it originates from the combination of weak solute-solvent attractive interactions and the specific excluded-volume effects associated with the small molecular size of water. However, a sharp distinction is found when exploring the temperature dependence of hydration phenomena since, in contrast to the situation for the constant-V process, the properties of pure water play a crucial role at isobaric conditions. Specifically, the solubility minimum as well as enthalpy and entropy convergence phenomena, exclusively ascribed to isobaric solvation, are closely related to water’s density maximum. Furthermore, the behavior of the partial molecular volume and the partial molecular isobaric heat capacity highlights the interplay between water anomalies, attraction, and repulsion. The overall picture presented here is supported by experimental observations, simulations, and previous theoretical results.
Two-center three-electron bonding in ClNH3 revealed via helium droplet infrared laser Stark spectroscopy: Entrance channel complex along the Cl + NH3 → ClNH2 + H reaction
Authors: Moradi Christopher P. , Xie Changjian , Kaufmann Matin , Guo Hua , Douberly Gary E.
Published: April 2016

Pyrolytic dissociation of Cl2 is employed to dope helium droplets with single Cl atoms. Sequential addition of NH3 to Cl-doped droplets leads to the formation of a complex residing in the entry valley to the substitution reaction Cl + NH3 → ClNH2 + H. Infrared Stark spectroscopy in the NH stretching region reveals symmetric and antisymmetric vibrations of a C3v symmetric top. Frequency shifts from NH3 and dipole moment measurements are consistent with a ClNH3 complex containing a relatively strong two-center three-electron (2c–3e) bond. The nature of the 2c–3e bonding in ClNH3 is explored computationally and found to be consistent with the complexation-induced blue shifts observed experimentally. Computations of interconversion pathways reveal nearly barrierless routes to the formation of this complex, consistent with the absence in experimental spectra of two other complexes, NH3Cl and Cl–HNH2, which are predicted in the entry valley to the hydrogen abstraction reaction Cl + NH3 → HCl + NH2.
Chromatic annuli formation and sample oxidation on copper thin films by femtosecond laser
Authors: He Shutong , Amoruso Salvatore , Pang Dongqing , Wang Chingyue , Hu Minglie
Published: April 2016

We report an experimental investigation on the irradiation of copper thin films with high repetition rate femtosecond laser pulses (1040 nm, 50 MHz), in ambient air and liquid water. We observe a novel, striking phenomenon of chromatic copper oxides (CuO and Cu2O) annuli generation. The characteristic features of the chromatic copper oxide annuli are studied by exploiting micro-Raman spectroscopy, optical and scanning electron microscopies. In the case of irradiation in water, the seldom investigated effects of the immersion time, tw, after irradiation with a fixed number of pulses are analyzed, and an intriguing dependence of the color of the chromatic annuli on tw is observed. This remarkable behavior is explained by proposing an interpretation scenario addressing the various processes involved in the process. Our experimental findings show that Cu2O nanoparticles (size of ≈20 nm) and Cu2O nanocubes (nanocube edges of ≈30, ≈60 nm) can be effectively generated by exploiting high repetition rate laser-assisted oxidation.
Enhancement of 800 nm upconversion emission in a thulium doped tellurite microstructured fiber pumped by a 1560 nm femtosecond fiber laser
Authors: Jia Zhixu , Yao Chuanfei , Wang Shunbin , Zheng Kezhi , Xiong Liangming , Luo Jie , Lv Dajuan , Qin Guanshi , Ohishi Yasutake , Qin Weiping
Published: April 2016

We report enhanced upconversion (UC) fluorescence in Tm3+ doped tellurite microstructured fibers (TDTMFs) fabricated by using a rod-in-tube method. Under the pumping of a 1560 nm femtosecond fiber laser, ultrabroadband supercontinuum light expanding from ∼1050 to ∼2700 nm was generated in a 4 cm long TDTMF. Simultaneously, intense 800 nm UC emission from the 3H4 → 3H6 transition of Tm3+ was observed in the same TDTMF. Compared to that pumped by a 1560 nm continuous wave fiber laser, the UC emission intensity was enhanced by ∼4.1 times. The enhancement was due to the spectral broadening in the TDTMF under the pumping of the 1560 nm femtosecond fiber laser.
A vacuum sealed high emission current and transmission efficiency carbon nanotube triode
Authors: Di Yunsong , Wang Qilong , Zhang Xiaobing , Lei Wei , Du Xiaofei , Yu Cairu
Published: April 2016

A vacuum sealed carbon nanotubes (CNTs) triode with a concave and spoke-shaped Mo grid is presented. Due to the high aperture ratio of the grid, the emission current could be modulated at a relatively high electric field. Totally 75mA emission current has been obtained from the CNTs cathode with the average applied field by the grid shifting from 8 to 13 V/μm. Whilst with the electron transmission efficiency of the grid over 56%, a remarkable high modulated current electron beam over 42mA has been collected by the anode. Also contributed by the high aperture ration of the grid, desorbed gas molecules could flow away from the emission area rapidly when the triode has been operated at a relative high emission current, and finally collected by a vacion pump. The working pressure has been maintained at ∼1 × 10−7 Torr, seldom spark phenomena occurred. Nearly perfect I-V curve and corresponding Fowler-Nordheim (FN) plot confirmed the accuracy of the measured data, and the emission current was long term stable and reproducible. Thusly, this kind of triode would be used as a high-power electron source.
Evaluation of polarization rotation in the scattering responses from individual semiconducting oxide nanorods
Authors: Choi Daniel S. , Singh Manpreet , Zhou Hebing , Milchak Marissa , Monahan Brian , Hahm Jong-in
Published: April 2016

We investigate the interaction of visible light with the solid matters of semiconducting oxide nanorods (NRs) of zinc oxide (ZnO), indium tin oxide (ITO), and zinc tin oxide (ZTO) at the single nanomaterial level. We subsequently identify an intriguing, material-dependent phenomenon of optical rotation in the electric field oscillation direction of the scattered light by systematically controlling the wavelength and polarization direction of the incident light, the NR tilt angle, and the analyzer angle. This polarization rotation effect in the scattered light is repeatedly observed from the chemically pure and highly crystalline ZnO NRs, but absent on the chemically doped NR variants of ITO and ZTO under all measurement circumstances. We further elucidate that the phenomenon of polarization rotation detected from single ZnO NRs is affected by the NR tilt angle, while the phenomenon itself occurs irrespective of the wavelength and incident polarization direction of the visible light. Combined with the widespread optical and optoelectronic use of the semiconducting oxide nanomaterials, these efforts may provide much warranted fundamental bases to tailor material-specific, single nanomaterial-driven, optically modulating functionalities which, in turn, can be beneficial for the realization of high-performance integrated photonic circuits and miniaturized bio-optical sensing devices.
Observation of a thermally enhanced magnetoresistance in NiFe
Authors: Cao Y. , Feng C. , Liu D. X. , Wang L. J. , Yang G. , Zhang J. Y. , Zhao B. , Jiang S. L. , Liu Q. Q. , Yang K. , Zelalem A. B. , Yu G. H.
Published: April 2016

A thermally enhanced magnetoresistance (ThMR) was designed and obtained by simultaneously applying charge and heat currents to a NiFe thin film. From the measurement we observed that the magnetoresistance value was as high as -22600% when the input charge current and applied temperature gradient was 0.966 μA and 2.5 °C/mm, respectively. This ThMR can be controllable by adjusting the relative values of the input charge and heat currents. On increasing the input charge current from 0.85 to 1.05 μA by fixing the temperature gradient at 2.5 °C/mm, the ThMR first increased from 9% to 183% and then decreased from -259% to -13%, at intervals of ∼0.96 μA. This can be explained by the spin-dependent transport phenomenon i.e., scattering induced sign difference between magnetoresistance and magnetothermopower in NiFe.
Dynamically tracking the joule heating effect on the voltage induced metal-insulator transition in VO2 crystal film
Authors: Liao G. M. , Chen S. , Fan L. L. , Chen Y. L. , Wang X. Q. , Ren H. , Zhang Z. M. , Zou C. W.
Published: April 2016

Insulator to metal phase transitions driven by external electric field are one of the hottest topics in correlated oxide study. While this electric triggered phenomena always mixes the electric field switching effect and joule thermal effect together, which are difficult to clarify the intrinsic mechanism. In this paper, we investigate the dynamical process of voltage-triggered metal-insulator transition (MIT) in a VO2 crystal film and observe the temperature dependence of the threshold voltages and switching delay times, which can be explained quite well based on a straightforward joule thermal model. By conducting the voltage controlled infrared transmittance measurement, the delayed infrared transmission change is also observed, further confirming the homogeneous switching process for a large-size film. All of these results show strong evidences that joule thermal effect plays a dominated role in electric-field-induced switching of VO2 crystal.
Discovery of an important aggregation area for endangered scalloped hammerhead sharks, Sphyrna lewini, in the Rewa River estuary, Fiji Islands
Authors: Brown Kelly T. , Seeto Johnson , Lal Monal M. , Miller Cara E.
Published: April 2016

The scalloped hammerhead shark, Sphyrna lewini, is endangered throughout its global distribution. Management and protection of this species is challenging in many locations because of limited scientific data and the vulnerable life-history traits of the species. Our study investigated anecdotal evidence that the Rewa River estuary in Fiji serves as an important nursery area for this shark. Research findings indicated that the average length of both males (60.6 ± 6.78 cm, n = 31) and females (60.4 ± 6.85 cm, n = 51) was well within published size limits of juvenile S. lewini studied in other locations (range = 38.0–89.5 cm). On the basis of published reference points for umbilical scar status we postulate that the first captured juveniles were born in January of the study year. Stomach content analysis found the following prey items: Decapoda (represented by prawns and shrimps), Stomatopoda, anguilliformes and osteichthyes. Decapods were the most numerous prey item by both count (59.17% of total prey items) and weight (60.25% of total weight). Our study provides strong support that the Rewa River estuary is an important aggregation area for S. lewini in Fiji.