bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-photon fluorescence lifetime imaging of primed SNARE complexes in presynaptic terminals and β cells
Authors: Takahashi Noriko , Sawada Wakako , Noguchi Jun , Watanabe Satoshi , Ucar Hasan , Hayashi-Takagi Akiko , Yagishita Sho , Ohno Mitsuyo , Tokumaru Hiroshi , Kasai Haruo 
Published: October 2015

AbstractIt remains unclear how readiness for Ca2+-dependent exocytosis depends on varying degrees of SNARE complex assembly. Here we directly investigate the SNARE assembly using two-photon fluorescence lifetime imaging (FLIM) of Förster resonance energy transfer (FRET) between three pairs of neuronal SNAREs in presynaptic boutons and pancreatic β cells in the islets of Langerhans. These FRET probes functionally rescue their endogenous counterparts, supporting ultrafast exocytosis. We show thattrans-SNARE complexes accumulated in the active zone, and estimate the number of complexes associated with each docked vesicle. In contrast, SNAREs were unassembled in resting state, and assembled only shortly prior to insulin exocytosis, which proceeds slowly. We thus demonstrate that distinct states of fusion readiness are associated with SNARE complex formation. Our FRET/FLIM approaches enable optical imaging of fusion readiness in both live and chemically fixed tissues.
Spin-dependent recombination probed through the dielectric polarizability
Authors: Bayliss Sam L. , Greenham Neil C. , Friend Richard H. , Bouchiat Hélène , Chepelianskii Alexei D 
Published: October 2015

AbstractDespite residing in an energetically and structurally disordered landscape, the spin degree of freedom remains a robust quantity in organic semiconductor materials due to the weak coupling of spin and orbital states. This enforces spin-selectivity in recombination processes which plays a crucial role in optoelectronic devices, for example, in the spin-dependent recombination of weakly bound electron-hole pairs, or charge-transfer states, which form in a photovoltaic blend. Here, we implement a detection scheme to probe the spin-selective recombination of these states through changes in their dielectric polarizability under magnetic resonance. Using this technique, we access a regime in which the usual mixing of spin-singlet and spin-triplet states due to hyperfine fields is suppressed by microwave driving. We present a quantitative model for this behaviour which allows us to estimate the spin-dependent recombination rate, and draw parallels with the Majorana–Brossel resonances observed in atomic physics experiments.
A Unified Material Description for Light Induced Deformation in Azobenzene Polymers
Authors: Bin Jonghoon , Oates William S. 
Published: October 2015

AbstractComplex light-matter interactions in azobenzene polymers have limited our understanding of how photoisomerization induces deformation as a function of the underlying polymer network and form of the light excitation. A unified modeling framework is formulated to advance the understanding of surface deformation and bulk deformation of polymer films that are controlled by linear or circularly polarized light or vortex beams. It is shown that dipole forces strongly respond to polarized light in contrast to higher order quadrupole forces that are often used to describe surface relief grating deformation through a field gradient constitutive law. The modeling results and comparisons with a broad range of photomechanical data in the literature suggest that the molecular structure of the azobenzene monomers dramatically influences the photostrictive behavior. The results provide important insight for designing azobenzene monomers within a polymer network to achieve enhanced photo-responsive deformation.
Comparative analysis of pentavalent rotavirus vaccine strains and G8 rotaviruses identified during vaccine trial in Africa
Authors: Heylen Elisabeth , Zeller Mark , Ciarlet Max , Lawrence Jody , Steele Duncan , Van Ranst Marc , Matthijnssens Jelle 
Published: October 2015

AbstractRotaTeqTM is a pentavalent rotavirus vaccine based on a bovine rotavirus genetic backbone in vitro reassorted with human outer capsid genes. During clinical trials of RotaTeqTM in Sub-Saharan Africa, the vaccine efficacy over a 2-year follow-up was lower against the genotypes contained in the vaccine than against the heterotypic G8P[6] and G8P[1] rotavirus strains of which the former is highly prevalent in Africa. Complete genome analyses of 43 complete rotavirus genomes collected during phase III clinical trials of RotaTeqTM in Sub-Saharan Africa, were conducted to gain insight into the high level of cross-protection afforded by RotaTeqTM against these G8 strains. Phylogenetic analysis revealed the presence of a high number of bovine rotavirus gene segments in these human G8 strains. In addition, we performed an in depth analysis on the individual amino acid level which showed that G8 rotaviruses were more similar to the RotaTeqTM vaccine than non-G8 strains. Because RotaTeqTM possesses a bovine genetic backbone, the high vaccine efficacy against G8 strains might be partially explained by the fact that all these strains contain a complete or partial bovine-like backbone. Altogether, this study supports the hypothesis that gene segments other than VP7 and VP4 play a role in vaccine-induced immunity.
Resolving Anomalies in Predicting Electrokinetic Energy Conversion Efficiencies of Nanofluidic Devices
Authors: Majumder Sagardip , Dhar Jayabrata , Chakraborty Suman 
Published: October 2015

AbstractWe devise a new approach for capturing complex interfacial interactions over reduced length scales, towards predicting electrokinetic energy conversion efficiencies of nanofluidic devices. By embedding several aspects of intermolecular interactions in continuum based formalism, we show that our simple theory becomes capable of representing complex interconnections between electro-mechanics and hydrodynamics over reduced length scales. The predictions from our model are supported by reported experimental data and are in excellent quantitative agreement with molecular dynamics simulations. The present model, thus, may be employed to rationalize the discrepancies between low energy conversion efficiencies of nanofluidic channels that have been realized from experiments and the impractically high energy conversion efficiencies that have been routinely predicted by the existing theories.
Direct Growth and Controlled Coalescence of Thick AlN Template on Micro-circle Patterned Si Substrate
Authors: Tran Binh Tinh , Hirayama Hideki , Maeda Noritoshi , Jo Masafumi , Toyoda Shiro , Kamata Norihiko 
Published: October 2015

AbstractHigh-density micro-circle patterned Si substrates were successfully fabricated for the direct overgrowth of thick AlN templates by using NH3 pulsed-flow multilayer AlN growth and epitaxial lateral overgrowth techniques. The experimental results show that an 8-μm-thick AlN template was grown at a very high growth rate on the substrates. The AlN template had full widths at half maximum of 0.23° and 0.37° for the (002) and (102) reflection planes in X-ray diffraction rocking curves. Atomic force microscopy and transmission electron microscopy confirmed that the roughness of the surface was low (3.5 nm) and the dislocation density was very low (1.5 × 108 cm−2 (screw), 3.7 × 108 (edge) cm−2).
Facile Carbon Fixation to Performic Acids by Water-Sealed Dielectric Barrier Discharge
Authors: Kawasaki Mitsuo , Morita Tatsuo , Tachibana Kunihide 
Published: October 2015

AbstractCarbon fixation refers to the conversion of carbon dioxide (CO2) to organic materials, as commonly performed in nature through photosynthesis by plants and other autotrophic organisms. The creation of artificial carbon fixation processes is one of the greatest challenges for chemistry to solve the critical environmental issue concerning the reduction of CO2 emissions. We have developed an electricity-driven facile CO2 fixation process that yields performic acid, HCO2OH, from CO2 and water at neutral pH by dielectric barrier discharge with an input electric power conversion efficiency of currently 0.2−0.4%. This method offers a promising future technology for artificial carbon fixation on its own and may also be scaled up in combination with e.g., the post-combustion CO2 capture and storage technology.
Kinetic characterization of trans-proteolytic activity of Chikungunya virus capsid protease and development of a FRET-based HTS assay
Authors: Aggarwal Megha , Sharma Rajesh , Kumar Pravindra , Parida Manmohan , Tomar Shailly 
Published: October 2015

AbstractChikungunya virus (CHIKV) capsid protein (CVCP) is a serine protease that possesses cis-proteolytic activity essential for the structural polyprotein processing and plays a key role in the virus life cycle. CHIKV being an emerging arthropod-borne pathogenic virus, is a public health concern worldwide. No vaccines or specific antiviral treatment is currently available for chikungunya disease. Thus, it is important to develop inhibitors against CHIKV enzymes to block key steps in viral reproduction. In view of this, CVCP was produced recombinantly and purified to homogeneity. A fluorescence resonance energy transfer (FRET)-based proteolytic assay was developed for high throughput screening (HTS). A FRET peptide substrate (DABCYL-GAEEWSLAIE-EDANS) derived from the cleavage site present in the structural polyprotein of CVCP was used. The assay with a Z’ factor of 0.64 and coefficient of variation (CV) is 8.68% can be adapted to high throughput format for automated screening of chemical libraries to identify CVCP specific protease inhibitors. Kinetic parameters Km and kcat/Km estimated using FRET assay were 1.26 ± 0.34 μM and 1.11 × 103 M−1 sec−1 respectively. The availability of active recombinant CVCP and cost effective fluorogenic peptide based in vitro FRET assay may serve as the basis for therapeutics development against CHIKV.
Xenopus borealis as an alternative source of oocytes for biophysical and pharmacological studies of neuronal ion channels
Authors: Cristofori-Armstrong Ben , Soh Ming S. , Talwar Sahil , Brown Darren L. , Griffin John D. O. , Dekan Zoltan , Stow Jennifer L. , King Glenn F. , Lynch Joseph W. , Rash Lachlan D. 
Published: October 2015

AbstractFor the past 30 years, oocytes from Xenopus laevis have been extensively used to express and characterise ion channels in an easily controlled environment. Here we report the first use of oocytes from the closely related species Xenopus borealis as an alternative expression system for neuronal ion channels. Using the two-electrode voltage-clamp technique, we show that a wide variety of voltage- and ligand-gated ion channels have the same channel properties and pharmacological profiles when expressed in either X. laevis or X. borealis oocytes. Potential advantages of the X. borealis oocytes include a smaller endogenous chloride current and the ability to produce more intense fluorescence signals when studied with voltage-clamp fluorometry. Scanning electron microscopy revealed a difference in vitelline membrane structure between the two species, which may be related to the discrepancy in fluorescence signals observed. We demonstrate that X. borealis oocytes are a viable heterologous system for expression of neuronal ion channels with some potential advantages over X. laevis oocytes for certain applications.
Induction of microglial toll-like receptor 4 by prothrombin kringle-2: a potential pathogenic mechanism in Parkinson’s disease
Authors: Shin Won-Ho , Jeon Min-Tae , Leem Eunju , Won So-Yoon , Jeong Kyoung Hoon , Park Sang-Joon , McLean Catriona , Lee Sung Joong , Jin Byung Kwan , Jung Un Ju , Kim Sang Ryoung 
Published: October 2015

AbstractMicroglia-mediated neuroinflammation may play an important role in the initiation and progression of dopaminergic (DA) neurodegeneration in Parkinson’s disease (PD) and toll-like receptor 4 (TLR4) is essential for the activation of microglia in the adult brain. However, it is still unclear whether patients with PD exhibit an increase in TLR4 expression in the brain and whether there is a correlation between the levels of prothrombin kringle-2 (pKr-2) and microglial TLR4. In the present study, we first observed that the levels of pKr-2 and microglial TLR4 were increased in the substantia nigra (SN) of patients with PD. In rat and mouse brains, intranigral injection of pKr-2, which is not directly toxic to neurons, led to the disruption of nigrostriatal DA projections. Moreover, microglial TLR4 was upregulated in the rat SN and in cultures of the BV-2 microglial cell line after pKr-2 treatment. In TLR4-deficient mice, pKr-2-induced microglial activation was suppressed compared with wild-type mice, resulting in attenuated neurotoxicity. Therefore, our results suggest that pKr-2 may be a pathogenic factor in PD and that the inhibition of pKr-2-induced microglial TLR4 may be protective against degeneration of the nigrostriatal DA systemin vivo.
The C-terminal amyloidogenic peptide contributes to self-assembly of Avibirnavirus viral protease
Authors: Zheng Xiaojuan , Jia Lu , Hu Boli , Sun Yanting , Zhang Yina , Gao Xiangxiang , Deng Tingjuan , Bao Shengjun , Xu Li , Zhou Jiyong 
Published: October 2015

AbstractUnlike other viral protease, Avibirnavirus infectious bursal disease virus (IBDV)-encoded viral protease VP4 forms unusual intracellular tubule-like structures during viral infection. However, the formation mechanism and potential biological functions of intracellular VP4 tubules remain largely elusive. Here, we show that VP4 can assemble into tubules in diverse IBDV-infected cells. Dynamic analysis show that VP4 initiates the assembly at early stage of IBDV infection and gradually assembles into larger size of fibrils within the cytoplasm and nucleus. Intracellular assembly of VP4 doesn’t involve the host cytoskeleton, other IBDV-encoded viral proteins or vital subcellular organelles. Interestingly, the last C-terminal hydrophobic and amyloidogenic stretch 238YHLAMA243 with two “aggregation-prone” alanine residues was found to be essential for its intracellular self-assembly. The assembled VP4 fibrils show significantly low solubility, subsequently, the deposition of highly assembled VP4 structures ultimately deformed the host cytoskeleton and nucleus, which was potentially associated with IBDV lytic infection. Importantly, the assembly of VP4 significantly reduced the cytotoxicity of protease activity in host cells which potentially prevent the premature cell death and facilitate viral replication. This study provides novel insights into the formation mechanism and biological functions of the Avibirnavirus protease-related fibrils.
Persistence and variation in microstructural design during the evolution of spider silk
Authors: Madurga R. , Blackledge T. A. , Perea B. , Plaza G. R. , Riekel C. , Burghammer M. , Elices M. , Guinea G. , Pérez-Rigueiro J. 
Published: October 2015

AbstractThe extraordinary mechanical performance of spider dragline silk is explained by its highly ordered microstructure and results from the sequences of its constituent proteins. This optimized microstructural organization simultaneously achieves high tensile strength and strain at breaking by taking advantage of weak molecular interactions. However, elucidating how the original design evolved over the 400 million year history of spider silk and identifying the basic relationships between microstructural details and performance have proven difficult tasks. Here we show that the analysis of maximum supercontracted single spider silk fibers using X ray diffraction shows a complex picture of silk evolution where some key microstructural features are conserved phylogenetically while others show substantial variation even among closely related species. This new understanding helps elucidate which microstructural features need to be copied in order to produce the next generation of biomimetic silk fibers.
Aberrant intra- and inter-network connectivity architectures in Alzheimer’s disease and mild cognitive impairment
Authors: Wang Pan , Zhou Bo , Yao Hongxiang , Zhan Yafeng , Zhang Zengqiang , Cui Yue , Xu Kaibin , Ma Jianhua , Wang Luning , An Ningyu , Zhang Xi , Liu Yong , Jiang Tianzi 
Published: October 2015

AbstractAlzheimer’s disease (AD) patients and those with high-risk mild cognitive impairment are increasingly considered to have dysfunction syndromes. Large-scale network studies based on neuroimaging techniques may provide additional insight into AD pathophysiology. The aim of the present study is to evaluate the impaired network functional connectivity with the disease progression. For this purpose, we explored altered functional connectivities based on previously well-defined brain areas that comprise the five key functional systems [the default mode network (DMN), dorsal attention network (DAN), control network (CON), salience network (SAL), sensorimotor network (SMN)] in 35 with AD and 27 with mild cognitive impairment (MCI) subjects, compared with 27 normal cognitive subjects. Based on three levels of analysis, we found that intra- and inter-network connectivity were impaired in AD. Importantly, the interaction between the sensorimotor and attention functions was first attacked at the MCI stage and then extended to the key functional systems in the AD individuals. Lower cognitive ability (lower MMSE scores) was significantly associated with greater reductions in intra- and inter-network connectivity across all patient groups. These profiles indicate that aberrant intra- and inter-network dysfunctions might be potential biomarkers or predictors of AD progression and provide new insight into AD pathophysiology.
Nanowire CdS-CdTe Solar Cells with Molybdenum Oxide as Contact
Authors: Dang Hongmei , Singh Vijay P. 
Published: October 2015

AbstractUsing a 10 nm thick molybdenum oxide (MoO3−x) layer as a transparent and low barrier contact to p-CdTe, we demonstrate nanowire CdS-CdTe solar cells with a power conversion efficiency of 11% under front side illumination. Annealing the as-deposited MoO3 film in N2 resulted in a reduction of the cell’s series resistance, from 9.97 Ω/cm2 to 7.69 Ω/cm2 and increase in efficiency from 9.9% to 11%. Under illumination from the back, the MoO3−x/Au side, the nanowire solar cells yielded Jsc of 21 mA/cm2 and efficiency of 8.67%. Our results demonstrate use of a thin layer transition metal oxide as a potential way for a transparent back contact to nanowire CdS-CdTe solar cells. This work has implications toward enabling a novel superstrate structure nanowire CdS-CdTe solar cell on Al foil substrate by a low cost roll-to roll fabrication process.
Efficient mass transport by optical advection
Authors: Kajorndejnukul Veerachart , Sukhov Sergey , Dogariu Aristide 
Published: October 2015

AbstractAdvection is critical for efficient mass transport. For instance, bare diffusion cannot explain the spatial and temporal scales of some of the cellular processes. The regulation of intracellular functions is strongly influenced by the transport of mass at low Reynolds numbers where viscous drag dominates inertia. Mimicking the efficacy and specificity of the cellular machinery has been a long time pursuit and, due to inherent flexibility, optical manipulation is of particular interest. However, optical forces are relatively small and cannot significantly modify diffusion properties. Here we show that the effectiveness of microparticle transport can be dramatically enhanced by recycling the optical energy through an effective optical advection process. We demonstrate theoretically and experimentally that this new advection mechanism permits an efficient control of collective and directional mass transport in colloidal systems. The cooperative long-range interaction between large numbers of particles can be optically manipulated to create complex flow patterns, enabling efficient and tunable transport in microfluidic lab-on-chip platforms.
Competition between global warming and an abrupt collapse of the AMOC in Earth’s energy imbalance
Authors: Drijfhout Sybren 
Published: October 2015

AbstractA collapse of the Atlantic Meridional Overturning Circulation (AMOC) leads to global cooling through fast feedbacks that selectively amplify the response in the Northern Hemisphere (NH). How such cooling competes with global warming has long been a topic for speculation, but was never addressed using a climate model. Here it is shown that global cooling due to a collapsing AMOC obliterates global warming for a period of 15–20 years. Thereafter, the global mean temperature trend is reversed and becomes similar to a simulation without an AMOC collapse. The resulting surface warming hiatus lasts for 40–50 years. Global warming and AMOC-induced NH cooling are governed by similar feedbacks, giving rise to a global net radiative imbalance of similar sign, although the former is associated with surface warming, the latter with cooling. Their footprints in outgoing longwave and absorbed shortwave radiation are very distinct, making attribution possible.
Genome-wide meta-analysis reveals common splice site acceptor variant in CHRNA4 associated with nicotine dependence
Authors: Hancock D B , Reginsson G W , Gaddis N C , Chen X , Saccone N L , Lutz S M , Qaiser B , Sherva R , Steinberg S , Zink F , Stacey S N , Glasheen C , Chen J , Gu F , Frederiksen B N , Loukola A , Gudbjartsson D F , Brüske I , Landi M T , Bickeböller H , Madden P , Farrer L , Kaprio J , Kranzler H R , Gelernter J , Baker T B , Kraft P , Amos C I , Caporaso N E , Hokanson J E , Bierut L J , Thorgeirsson T E , Johnson E O , Stefansson K 
Published: October 2015

AbstractWe conducted a 1000 Genomes–imputed genome-wide association study (GWAS) meta-analysis for nicotine dependence, defined by the Fagerström Test for Nicotine Dependence in 17 074 ever smokers from five European-ancestry samples. We followed up novel variants in 7469 ever smokers from five independent European-ancestry samples. We identified genome-wide significant association in the alpha-4 nicotinic receptor subunit (CHRNA4) gene on chromosome 20q13: lowest P=8.0 × 10−9 across all the samples for rs2273500-C (frequency=0.15; odds ratio=1.12 and 95% confidence interval=1.08–1.17 for severe vs mild dependence). rs2273500-C, a splice site acceptor variant resulting in an alternate CHRNA4 transcript predicted to be targeted for nonsense-mediated decay, was associated with decreased CHRNA4 expression in physiologically normal human brains (lowest P=7.3 × 10−4). Importantly, rs2273500-C was associated with increased lung cancer risk (N=28 998, odds ratio=1.06 and 95% confidence interval=1.00–1.12), likely through its effect on smoking, as rs2273500-C was no longer associated with lung cancer after adjustment for smoking. Using criteria for smoking behavior that encompass more than the single ‘cigarettes per day’ item, we identified a common CHRNA4 variant with important regulatory properties that contributes to nicotine dependence and smoking-related consequences.