bluuebunny/crossref_metadata_2025 huggingface dataset:
A High Resolution Spectrograph at Weihai Observatory
Authors: Gao Dongyang , Ren Dayong
Published: April 2014

Weihai Echelle Spectrograph (WES) is the first the fiber-fed echelle spectrograph in China. WES can provide data for the studies of metal abundance of stars, exoplanets researches and asteroseismology, etc. A brief description of its design and performance is given.
Simulator for Microlens Planet Surveys
Authors: Ipatov Sergei I. , Horne Keith , Alsubai Khalid A. , Bramich Daniel M. , Dominik Martin , Hundertmark Markus P. G. , Liebig Christine , Snodgrass Colin D. B. , Street Rachel A. , Tsapras Yiannis
Published: April 2014

We summarize the status of a computer simulator for microlens planet surveys. The simulator generates synthetic light curves of microlensing events observed with specified networks of telescopes over specified periods of time. Particular attention is paid to models for sky brightness and seeing, calibrated by fitting to data from the OGLE survey and RoboNet observations in 2011. Time intervals during which events are observable are identified by accounting for positions of the Sun and the Moon, and other restrictions on telescope pointing. Simulated observations are then generated for an algorithm that adjusts target priorities in real time with the aim of maximizing planet detection zone area summed over all the available events. The exoplanet detection capability of observations was compared for several telescopes.
HSTEP – Homogeneous Studies of Transiting Extrasolar Planets
Authors: Southworth John
Published: April 2014

This paper presents a summary of the HSTEP project: an effort to calculate the physical properties of the known transiting extrasolar planets using a homogeneous approach. I discuss the motivation for the project, list the 83 planets which have already been studied, run through some important aspects of the methodology, and finish with a synopsis of the results.
The ELODIE and SOPHIE Search for Northern Extrasolar Planets: Jupiter-Analogs around Sun-Like Stars
Authors: Boisse I. , Pepe F. , Perrier C. , Queloz D. , Bouchy F. , Santos N. C. ,   the SOPHIE team
Published: April 2014

We present radial-velocity measurements (RV) obtained in one of the numbers of programs underway to search for extrasolar planets with the spectrograph SOPHIE at the 1.93-m telescope of the Observatoire de Haute-Provence. Targets were selected from catalogs observed with ELODIE, which had been mounted previously at the telescope, in order to detect long-period planets with an extended database close to 15 years.
NKT cell depletion in humans during early HIV infection
Authors: Fernandez Caroline S , Kelleher Anthony D , Finlayson Robert , Godfrey Dale I , Kent Stephen J
Published: April 2014

Natural killer T (NKT) cells bridge across innate and adaptive immune responses and have an important role in chronic viral infections such as human immunodeficiency virus (HIV). NKT cells are depleted during chronic HIV infection, but the timing, drivers and implications of this NKT cell depletion are poorly understood. We studied human peripheral blood NKT cell levels, phenotype and function in 31 HIV‐infected subjects not on antiretroviral treatment from a mean of 4 months to 2 years after HIV infection. We found that peripheral CD4+ NKT cells were substantially depleted and dysfunctional by 4 months after HIV infection. The depletion of CD4+ NKT cells was more marked than the depletion of total CD4+ T cells. Further, the early depletion of NKT cells correlated with CD4+ T‐cell decline, but not HIV viral levels. Levels of activated CD4+ T cells correlated with the loss of NKT cells. Our studies suggest that the early loss of NKT cells is associated with subsequent immune destruction during HIV infection.
C5a2 can modulate ERK1/2 signaling in macrophages via heteromer formation with C5a1 and β‐arrestin recruitment
Authors: Croker Daniel E , Halai Reena , Kaeslin Geraldine , Wende Elisabeth , Fehlhaber Beate , Klos Andreas , Monk Peter N , Cooper Matthew A
Published: April 2014

The complement system is a major component of our innate immune system, in which the complement proteins C5a and C5a‐des Arg bind to two G‐protein‐coupled receptors: namely, the C5a receptor (C5a1) and C5a receptor like‐2 receptor (C5a2, formerly called C5L2). Recently, it has been demonstrated that C5a, but not C5a‐des Arg, upregulates heteromer formation between C5a1 and C5a2, leading to an increase in IL‐10 release from human monocyte‐derived macrophages (HMDMs). A bioluminescence resonance energy transfer (BRET) assay was used to assess the recruitment of β‐arrestins by C5a and C5a‐des Arg at the C5a1 and C5a2 receptors. C5a demonstrated elevated β‐arrestin 2 recruitment levels in comparison with C5a‐des Arg, whereas no significant difference was observed at C5a2. A constitutive complex that formed between β‐arrestin 2 and C5a2 accounted for half of the BRET signal observed. Interestingly, both C5a and C5a‐des Arg exhibited higher potency for β‐arrestin 2 recruitment via C5a2, indicating preference for C5a2 over C5a1. When C5a was tested in a functional ERK1/2 assay in HMDMs, inhibition of ERK1/2 was observed only at concentrations at or above the EC50 for heteromer formation. This suggested that increased recruitment of the β‐arrestin‐C5a2 complex at these C5a concentrations might have an inhibitory role on C5a1 signaling through ERK1/2. An improved understanding of C5a2 modulation of signaling in acute inflammation could be of benefit in the development of ligands for conditions such as sepsis.
Reprograming of gut microbiome energy metabolism by theFUT2Crohn’s disease risk polymorphism
Authors: Tong Maomeng , McHardy Ian , Ruegger Paul , Goudarzi Maryam , Kashyap Purna C , Haritunians Talin , Li Xiaoxiao , Graeber Thomas G , Schwager Emma , Huttenhower Curtis , Fornace Albert J , Sonnenburg Justin L , McGovern Dermot P B , Borneman James , Braun Jonathan
Published: April 2014

Fucosyltransferase 2 (FUT2) is an enzyme that is responsible for the synthesis of the H antigen in body fluids and on the intestinal mucosa. The H antigen is an oligosaccharide moiety that acts as both an attachment site and carbon source for intestinal bacteria. Non-secretors, who are homozygous for the loss-of-function alleles of FUT2 gene (sese), have increased susceptibility to Crohn’s disease (CD). To characterize the effect of FUT2 polymorphism on the mucosal ecosystem, we profiled the microbiome, meta-proteome and meta-metabolome of 75 endoscopic lavage samples from the cecum and sigmoid of 39 healthy subjects (12 SeSe, 18 Sese and 9 sese). Imputed metagenomic analysis revealed perturbations of energy metabolism in the microbiome of non-secretor and heterozygote individuals, notably the enrichment of carbohydrate and lipid metabolism, cofactor and vitamin metabolism and glycan biosynthesis and metabolism-related pathways, and the depletion of amino-acid biosynthesis and metabolism. Similar changes were observed in mice bearing the FUT2−/− genotype. Metabolomic analysis of human specimens revealed concordant as well as novel changes in the levels of several metabolites. Human metaproteomic analysis indicated that these functional changes were accompanied by sub-clinical levels of inflammation in the local intestinal mucosa. Therefore, the colonic microbiota of non-secretors is altered at both the compositional and functional levels, affecting the host mucosal state and potentially explaining the association of FUT2 genotype and CD susceptibility.
Mutation rate plasticity in rifampicin resistance depends on Escherichia coli cell–cell interactions
Authors: Krašovec Rok , Belavkin Roman V. , Aston John A. D. , Channon Alastair , Aston Elizabeth , Rash Bharat M. , Kadirvel Manikandan , Forbes Sarah , Knight Christopher G.
Published: April 2014

Variation of mutation rate at a particular site in a particular genotype, in other words mutation rate plasticity (MRP), can be caused by stress or ageing. However, mutation rate control by other factors is less well characterized. Here we show that in wild-typeEscherichia coli(K-12 and B strains), the mutation rate to rifampicin resistance is plastic and inversely related to population density: lowering density can increase mutation rates at least threefold. This MRP is genetically switchable, dependent on the quorum-sensing geneluxS—specifically its role in the activated methyl cycle—and is socially mediated via cell–cell interactions. Although we identify an inverse association of mutation rate with fitness under some circumstances, we find no functional link with stress-induced mutagenesis. Our experimental manipulation of mutation rates via the social environment raises the possibility that such manipulation occurs in nature and could be exploited medically.
Whole-genome sequencing of bladder cancers reveals somatic CDKN1A mutations and clinicopathological associations with mutation burden
Authors: Cazier J. -B. , Rao S. R. , McLean C. M. , Walker A. K. , Wright B. J. , Jaeger E. E. M. , Kartsonaki C. , Marsden L. , Yau C. , Camps C. , Kaisaki P. ,   The Oxford-Illumina WGS500 Consortium, Allan Christopher , Attar Moustafa , Bell John , Bentley David , Broxholme John , Buck David , Cazier Jean-Baptiste , Copley Richard , Cornall Richard , Donnelly Peter , Fiddy Simon , Green Angie , Gregory Lorna , Grocock Russell , Hatton Edouard , Holmes Chris , Hughes Linda , Humburg Peter , Humphray Sean , Kanapin Alexander , Kingsbury Zoya , Knight Julian , Lamble Sarah , Lise Stefano , Lonie Lorne , Lunter Gerton , Martin Hilary , Murray Lisa , McCarthy Davis , McVean Gil , Pagnamenta Alistair , Piazza Paolo , Polanco Guadelupe , Ratcliffe Peter , Rimmer Andy , Sahgal Natasha , Taylor Jenny , Tomlinson Ian , Trebes Amy , Wilkie Andrew , Wright Ben , Yau Chris , Taylor J. , Catto J. W. , Tomlinson I. P. M. , Kiltie A. E. , Hamdy F. C.
Published: April 2014

Bladder cancers are a leading cause of death from malignancy. Molecular markers might predict disease progression and behaviour more accurately than the available prognostic factors. Here we use whole-genome sequencing to identify somatic mutations and chromosomal changes in 14 bladder cancers of different grades and stages. As well as detecting the known bladder cancer driver mutations, we report the identification of recurrent protein-inactivating mutations in CDKN1A and FAT1. The former are not mutually exclusive with TP53 mutations or MDM2 amplification, showing that CDKN1A dysfunction is not simply an alternative mechanism for p53 pathway inactivation. We find strong positive associations between higher tumour stage/grade and greater clonal diversity, the number of somatic mutations and the burden of copy number changes. In principle, the identification of sub-clones with greater diversity and/or mutation burden within early-stage or low-grade tumours could identify lesions with a high risk of invasive progression.
Faster growth of the major prokaryotic versus eukaryotic CO2 fixers in the oligotrophic ocean
Authors: Zubkov Mikhail V.
Published: April 2014

Because maintenance of non-scalable cellular components—membranes and chromosomes—requires an increasing fraction of energy as cell size decreases, miniaturization comes at a considerable energetic cost for a phytoplanktonic cell. Consequently, if eukaryotes can use their superior energetic resources to acquire nutrients with more or even similar efficiency compared with prokaryotes, larger unicellular eukaryotes should be able to achieve higher growth rates than smaller cyanobacteria. Here, to test this hypothesis, we directly compare the intrinsic growth rates of phototrophic prokaryotes and eukaryotes from the equatorial to temperate South Atlantic using an original flow cytometric 14CO2-tracer approach. At the ocean basin scale, cyanobacteria double their biomass twice as frequently as the picoeukaryotes indicating that the prokaryotes are faster growing CO2 fixers, better adapted to phototrophic living in the oligotrophic open ocean—the most extensive biome on Earth.
Non-contact assessment of COD and turbidity concentrations in water using diffuse reflectance UV-Vis spectroscopy
Authors: Agustsson Jon , Akermann Oliver , Barry D. Andrew , Rossi Luca
Published: April 2014

Water contamination is an important environmental concern, requiring reliable real-time information on contaminant concentrations in natural waters. Here, a new non-contact UV-Vis spectroscopic approach for monitoring contaminants in water, and especially wastewater, is proposed.
Alpha linolenic acid (ALA) from Rosa canina, sacha inchi and chia oils may increase ALA accretion and its conversion into n-3 LCPUFA in diverse tissues of the rat
Authors: Valenzuela B Rodrigo , Barrera R Cynthia , González-Astorga Marcela , Sanhueza C Julio , Valenzuela B Alfonso
Published: April 2014

Alpha-linolenic acid (ALA) is an essentialn-3 PUFA; itsn-3 LCPUFA derivatives EPA and DHA, which have diverse beneficial effects, are scarce in the human diet.
Ozone dosage effect on C6 cell growth, in vitro and in vivo tests: double bond index for characterization
Authors: Pérez Arizbeth , Santos Cuevas Clara L. , Chairez Isaac , Poznyak Tatyana , Ordaz-Rosado David , García-Becerra Rocío , Romero Piña Mario E.
Published: April 2014

Ozone dissolved in a saline solution applied as a medical therapy promoted an 85% decrement in C6 tumor activity.
Determination of multi-residue PCBs in air by real-time fluorescent quantitative immuno-PCR assay
Authors: Chen Han-Yu , Zhuang Hui-Sheng , Yang Guang-Xin
Published: April 2014

Amplification curves of a dilution series of Aroclor 1248 of direct competition rt-IPCR. In the figure, the fluorescence signal of the curve (10 fg mL−1) reaching the threshold was at around cycle 12.3, and there was a fall in the Ct value from 10 to 106 fg mL−1. This result implied that the time expended to reach the threshold for the high concentration of PCB molecules was much longer than for the low concentration PCBs.
Hoechst tagging: a modular strategy to design synthetic fluorescent probes for live-cell nucleus imaging
Authors: Nakamura Akinobu , Takigawa Kazumasa , Kurishita Yasutaka , Kuwata Keiko , Ishida Manabu , Shimoda Yasushi , Hamachi Itaru , Tsukiji Shinya
Published: April 2014

Attachment of the Hoechst tag to fluorescent molecules allows the creation of (turn-on) fluorescent nucleus-imaging probes.
An unusual water-bridged homospin CoII single-chain magnet
Authors: Ma Xiaozhou , Zhang Zhenjie , Shi Wei , Li Leilei , Zou Jiyong , Cheng Peng
Published: April 2014

A 3D coordination polymer has been constructed by linking water-bridged cobalt chains via dicarboxylic ligands to show interesting SCM behaviour.
B182−: a quasi-planar bowl member of the Wankel motor family
Authors: Moreno Diego , Pan Sudip , Zeonjuk Lei Liu , Islas Rafael , Osorio Edison , Martínez-Guajardo Gerardo , Chattaraj Pratim K. , Heine Thomas , Merino Gabriel
Published: April 2014

A quasi-planar member of the so-called ‘Wankel motor’ family, B182−, is found.
Chiral squaramide-catalyzed asymmetric synthesis of pyranones and pyranonaphthoquinones via cascade reactions of 1,3-dicarbonyls with Morita–Baylis–Hillman acetates of nitroalkenes
Authors: Nair Divya K. , Menna-Barreto Rubem F. S. , da Silva Júnior Eufrânio N. , Mobin Shaikh M. , Namboothiri Irishi N. N.
Published: April 2014

Catalytic asymmetric synthesis of α-lapachones from hydroxynaphthoquinone and Morita–Baylis–Hillman acetates of nitroalkenes is described.
Direct CO oxidation by lattice oxygen on the SnO2(110) surface: a DFT study
Authors: Lu Zhansheng , Ma Dongwei , Yang Lin , Wang Xiaobing , Xu Guoliang , Yang Zongxian
Published: April 2014

The process of CO oxidation by lattice oxygen on the SnO2(110) surface and the recovery of the reduced surface by O2 is presented.
Plasmonic rod-in-shell nanoparticles for photothermal therapy
Authors: Wang Shanshan , Xu Hong , Ye Jian
Published: April 2014

The plasmonic rod-in-shell nanoparticles have a number of favorable optical properties for the photothermal therapy application compared to the nanorods: increased longitudinal and transversal absorption cross-sections in the NIR window I, a larger and highly tunable absorption cross-section in the NIR window II, orientation of particles insensitive to the heat generation.
Reaction rate constants of H-abstraction by OH from large ketones: measurements and site-specific rate rules
Authors: Badra Jihad , Elwardany Ahmed E. , Farooq Aamir
Published: April 2014

Reaction rate constants of the reaction of four large ketones with hydroxyl (OH) are investigated behind reflected shock waves using OH laser absorption.
Understanding the directed ortho lithiation of (R)-Ph2P(NCO2Me)NHCH(Me)Ph. NMR spectroscopic and computational study of the structure of the N-lithiated species
Authors: Casimiro M. , García-López J. , Iglesias M. J. , López-Ortiz F.
Published: April 2014

The multinuclear magnetic resonance and computational study of the structure ofN-lithium (R)-Ph2P(NCO2Me)NHCH(Me)Ph revealed the origin of its diastereoselectiveortholithiation.
Evolution of disposable bamboo chopsticks into uniform carbon fibers: a smart strategy to fabricate sustainable anodes for Li-ion batteries
Authors: Jiang Jian , Zhu Jianhui , Ai Wei , Fan Zhanxi , Shen Xiaonan , Zou Chenji , Liu Jinping , Zhang Hua , Yu Ting
Published: April 2014

Uniform carbon fibers evolved from bamboo chopsticks garbage are achieved by a facile hydrothermal method, exhibiting competitive electrochemical behavior with commercial graphite, or pretty high anodic performance after being optimized.
Organohalide lead perovskites for photovoltaic applications
Authors: Gao Peng , Grätzel Michael , Nazeeruddin Mohammad K.
Published: April 2014

This review presents the state-of-the-art organohalide lead perovskites, which are currently making an immense impact across the photovoltaic community.
Unconventional oil and gas extraction and animal health
Authors: Bamberger M. , Oswald R. E.
Published: April 2014

This perspectives article discusses the authors' views of the impacts of unconventional oil and gas extraction on animal health and food safety.
Life cycle assessment of polyols for polyurethane production using CO2 as feedstock: insights from an industrial case study
Authors: von der Assen Niklas , Bardow André
Published: April 2014

Life cycle assessment is used to determine impact reductions for greenhouse gas emission and fossil resource depletion for production of polyethercarbonate polyols using CO2 from flue gases as feedstock.
Photon upconversion sensitized nanoprobes for sensing and imaging of pH
Authors: Arppe Riikka , Näreoja Tuomas , Nylund Sami , Mattsson Leena , Koho Sami , Rosenholm Jessica M. , Soukka Tero , Schäferling Michael
Published: April 2014

Ratiometric referenced luminescent pH nanosensors based on an upconversion resonance energy transfer (UC-RET) process enable imaging applications with NIR excitation.
Cu–Ni nanoparticle-decorated graphene based photodetector
Authors: Kumar Anil , Husale Sudhir , Srivastava A. K. , Dutta P. K. , Dhar Ajay
Published: April 2014

The in situ growth of a Cu–Ni nanoparticle-decorated graphene nano-composite has been explored as a photodetector.
Highly branched platinum nanolance assemblies by polyallylamine functionalization as superior active, stable, and alcohol-tolerant oxygen reduction electrocatalysts
Authors: Fu Gengtao , Jiang Xian , Gong Mingxing , Chen Yu , Tang Yawen , Lin Jun , Lu Tianhong
Published: April 2014

The chemical functionalized platinum nanolance assemblies exhibit superior electrocatalytic activity, alcohol tolerance and durability for oxygen reduction reaction.
Tuning the growth mode of nanowires via the interaction among seeds, substrates and beam fluxes
Authors: Zannier Valentina , Grillo Vincenzo , Martelli Faustino , Plaisier Jasper Rikkert , Lausi Andrea , Rubini Silvia
Published: April 2014

The growth mechanism of semiconductor nanowires is tuned changing the physical state of the metallic seeds by varying their chemical composition.
Molecular release from patterned nanoporous gold thin films
Authors: Kurtulus Ozge , Daggumati Pallavi , Seker Erkin
Published: April 2014

Patterned nanoporous gold thin films exhibit high loading capacity and tunable release kinetics for small molecules.
In
situ monitored engineering of inverted nanoporous anodic alumina funnels: on the precise generation of 3D optical nanostructures
Authors: Santos Abel , Kumeria Tushar , Wang Ye , Losic Dusan
Published: April 2014

Inverted nanoporous anodic alumina funnels (INAAFs) are produced by in-depth electrochemical/thermal engineering of nanoporous anodic alumina.
Graphene quantum dots, graphene oxide, carbon quantum dots and graphite nanocrystals in coals
Authors: Dong Yongqiang , Lin Jianpeng , Chen Yingmei , Fu Fengfu , Chi Yuwu , Chen Guonan
Published: April 2014

Six coal samples of different ranks were revealed to contain large amounts of graphene quantum dots, graphene oxide, carbon quantum dots, agglomerated GQDs and agglomerated carbon nanocrystals.
Rhodium(iii)-catalyzed coupling of N-sulfonyl 2-aminobenzaldehydes with oxygenated allylic olefins through C–H activation
Authors: Yang Tingting , Zhang Tao , Yang Shangdong , Chen Shanshan , Li Xingwei
Published: April 2014

N-Sulfonyl-2-aminobenzaldehyde undergoes C–H activation and coupling with oxygenated allylic olefins under redox-neutral conditions with high efficiency.
Efficient palladium-catalyzed double carbonylation of o-dibromobenzenes: synthesis of thalidomide
Authors: Chen Jianbin , Natte Kishore , Spannenberg Anke , Neumann Helfried , Beller Matthias , Wu Xiao-Feng
Published: April 2014

A convenient and mild procedure for double carbonylation of o-dibromobenzene with various 2-amino pyridines and naturally occurring amines has been developed. N-Substituted phthalimides were produced in good to excellent yields. Furthermore, thalidomide was produced in excellent yield under these conditions.
Theoretical calculations of the kinetics of the OH reaction with 2-methyl-2-propen-1-ol and its alkene analogue
Authors: Barbosa Thaís da Silva , Nieto Jorge D. , Cometto Pablo M. , Lane Silvia I. , Bauerfeldt Glauco Favilla , Arbilla Graciela
Published: April 2014

The rate coefficients for the OH addition to 2-methyl-2-propen-1-ol and methylpropene have been determined, showing a non-Arrhenius profile and good agreement with the experimental data.
Role of Li+ion in the luminescence enhancement of lanthanide ions: favorable modifications in host matrices
Authors: Singh A. K. , Singh S. K. , Rai S. B.
Published: April 2014

The effect of alkali ions on the modification of various host matrices and their effects on the luminescence properties of lanthanide ions have been demonstrated in this comprehensive review.
Influence of the relative humidity on the morphology of inkjet printed spots of IgG on a non-porous substrate
Authors: Mujawar Liyakat Hamid , Kuerten J. G. M. , Siregar D. P. , van Amerongen Aart , Norde Willem
Published: April 2014

During the drying of inkjet printed droplets, the solute particles (IgG-Alexa-635 molecules) in the drop may distribute unevenly on the substrate, resulting in a “coffee-stain” spot morphology.
Controlled synthesis of yolk–mesoporous shell Si@SiO2nanohybrid designed for high performance Li ion battery
Authors: Sun Zhuang , Song Xuefeng , Zhang Peng , Gao Lian
Published: April 2014

Yolk–mesoporous shell Si@SiO2nanohybrids with controllable shell thickness were preparedviaa facile vesicle-template method, which exhibit good cycle performance and excellent rate capabilities.
Light-induced cell aggregation of Euglena gracilis towards economically feasible biofuel production
Authors: Ooka Hideshi , Ishii Takumi , Hashimoto Kazuhito , Nakamura Ryuhei
Published: April 2014

Using the photoresponse of the green algae Euglena gracilis, we demonstrate a novel and economically feasible method for cell aggregation.
Fundamental aspects of the nucleic acid i-motif structures
Authors: Benabou S. , Aviñó A. , Eritja R. , González C. , Gargallo R.
Published: April 2014

The latest research on fundamental aspects of i-motif structures is reviewed with special attention to their hypothetical rolein vivo.
Structural optimization of super-gelators derived from naturally-occurring mannose and their morphological diversity
Authors: Ono Fumiyasu , Watanabe Hisayuki , Shinkai Seiji
Published: April 2014

Mannose derivatives with various alkoxy substituents are able to gelate organic solvents and protic solvents. These gelators impart transparency, stability and thixotropic behavior to the gels.
Chitin–calcium alginate composite fibers for wound care dressings spun from ionic liquid solution
Authors: Shamshina J. L. , Gurau G. , Block L. E. , Hansen L. K. , Dingee C. , Walters A. , Rogers R. D.
Published: April 2014

Chitin–calcium alginate composite fibers prepared from ionic liquid solutions of high molecular weight chitin and alginic acid by dry-jet wet spinning into a saturated CaCO3 solution, provided complete rat model wound closure in 14 days.
Aptamer-functionalized graphene oxide for highly efficient loading and cancer cell-specific delivery of antitumor drug
Authors: Lu Yimei , Wu Ping , Yin Yajing , Zhang Hui , Cai Chenxin
Published: April 2014

A novel anticancer drug loading and cell-specific delivery system based on cell-type-specific aptamer-functionalized graphene oxide is reported.
Discrimination of homocysteine, cysteine and glutathione using an aggregation-induced-emission-active hemicyanine dye
Authors: Chen Sijie , Hong Yuning , Liu Jianzhao , Tseng Nai-Wen , Liu Yang , Zhao Engui , Yip Lam Jacky Wing , Tang Ben Zhong
Published: April 2014

An aggregation-induced-emission active hemicyanine dye, TPE-Cy, shows high selectivity to homocysteine over glutathione and other amino acids.
Facile fabrication of ultrathin graphene papers for effective electromagnetic shielding
Authors: Song Wei-Li , Fan Li-Zhen , Cao Mao-Sheng , Lu Ming-Ming , Wang Chan-Yuan , Wang Jia , Chen Tian-Tian , Li Yong , Hou Zhi-Ling , Liu Jia , Sun Ya-Ping
Published: April 2014

Novel conductive ultrathin graphene papers demonstrate effective EMI shielding of ∼46.3 dB (∼0.3 mm) and ∼47.7 dB (∼0.1 mm) in attenuators.
Synthesis of Ag doped ZnlnSe ternary quantum dots with tunable emission
Authors: Wang Chunlei , Xu Shuhong , Shao Yujie , Wang Zhuyuan , Xu Qinying , Cui Yiping
Published: April 2014

Ag:ZnInSe QDs with extremely good stability, good biocompatibility, low cytotoxicity and continuously tunable wavelengths from 504 nm to 585 nm.
High ON/OFF ratio single crystal transistors based on ultrathin thienoacene microplates
Authors: Zhao Xiaoli , Pei Tengfei , Cai Bin , Zhou Shujun , Tang Qingxin , Tong Yanhong , Tian Hongkun , Geng Yanhou , Liu Yichun
Published: April 2014

Based on Ph5T2 and OTS modification of the dielectric, ultrathin single crystal microplate transistors with a high ON/OFF ratio up to 108 can be obtained.
Biochemical analysis of TssK, a core component of the bacterial Type VI secretion system, reveals distinct oligomeric states of TssK and identifies a TssK–TssFG subcomplex
Authors: English Grant , Byron Olwyn , Cianfanelli Francesca R. , Prescott Alan R. , Coulthurst Sarah J.
Published: April 2014

Gram-negative bacteria use the Type VI secretion system (T6SS) to inject toxic proteins into rival bacteria or eukaryotic cells. However, the mechanism of the T6SS is incompletely understood. In the present study, we investigated a conserved component of the T6SS, TssK, using the antibacterial T6SS of Serratia marcescens as a model system. TssK was confirmed to be essential for effector secretion by the T6SS. The native protein, although not an integral membrane protein, appeared to localize to the inner membrane, consistent with its presence within a membrane-anchored assembly. Recombinant TssK purified from S. marcescens was found to exist in several stable oligomeric forms, namely trimer, hexamer and higher-order species. Native-level purification of TssK identified TssF and TssG as interacting proteins. TssF and TssG, conserved T6SS components of unknown function, were required for T6SS activity, but not for correct localization of TssK. A complex containing TssK, TssF and TssG was subsequently purified in vitro, confirming that these three proteins form a new subcomplex within the T6SS. Our findings provide new insight into the T6SS assembly, allowing us to propose a model whereby TssK recruits TssFG into the membrane-associated T6SS complex and different oligomeric states of TssK may contribute to the dynamic mechanism of the system.
Endoplasmic reticulum stress does not contribute to steatohepatitis in obese and insulin-resistant high-fat-diet-fed foz/foz mice
Authors: Legry Vanessa , Van Rooyen Derrick M. , Lambert Barbara , Sempoux Christine , Poekes Laurence , Español-Suñer Regina , Molendi-Coste Olivier , Horsmans Yves , Farrell Geoffrey C. , Leclercq Isabelle A.
Published: April 2014

Non-alcoholic fatty liver (steatosis) and steatohepatitis [non-alcoholic steatohepatitis (NASH)] are hepatic complications of the metabolic syndrome. Endoplasmic reticulum (ER) stress is proposed as a crucial disease mechanism in obese and insulin-resistant animals (such as ob/ob mice) with simple steatosis, but its role in NASH remains controversial. We therefore evaluated the role of ER stress as a disease mechanism in foz/foz mice, which develop both the metabolic and histological features that mimic human NASH. We explored ER stress markers in the liver of foz/foz mice in response to a high-fat diet (HFD) at several time points. We then evaluated the effect of treatment with an ER stress inducer tunicamycin, or conversely with the ER protectant tauroursodeoxycholic acid (TUDCA), on the metabolic and hepatic features. foz/foz mice are obese, glucose intolerant and develop NASH characterized by steatosis, inflammation, ballooned hepatocytes and apoptosis from 6 weeks of HFD feeding. This was not associated with activation of the upstream unfolded protein response [phospho-eukaryotic initiation factor 2α (eIF2α), inositol-requiring enzyme 1α (IRE1α) activity and spliced X-box-binding protein 1 (Xbp1)]. Activation of c-Jun N-terminal kinase (JNK) and up-regulation of activating transcription factor-4 (Atf4) and CCAAT/enhancer-binding protein-homologous protein (Chop) transcripts were however compatible with a ‘pathological’ response to ER stress. We tested this by using intervention experiments. Induction of chronic ER stress failed to worsen obesity, glucose intolerance and NASH pathology in HFD-fed foz/foz mice. In addition, the ER protectant TUDCA, although reducing steatosis, failed to improve glucose intolerance, hepatic inflammation and apoptosis in HFD-fed foz/foz mice. These results show that signals driving hepatic inflammation, apoptosis and insulin resistance are independent of ER stress in obese diabetic mice with steatohepatitis.
Telepractice: An Overview and Best Practices
Authors: Cason Jana , Cohn Ellen R.
Published: April 2014

Telepractice is the use of telecommunications technology to deliver speech therapy and audiology services to a client who is in a different physical location than the practitioner. This article presents a general overview of telepractice, including terminology and definitions; ethical considerations; privacy and security; reimbursement policy and trends; considerations for client selection; and telepractice resources. It was written to provide foundational information about telepractice for practitioners who are engaged with alternative and augmentative communication (AAC).
Baseband tuning of Cartesian delta–sigma RF upconverters
Authors: Sirmayanti S. , Bassoo V. , King H. , Faulkner M.
Published: April 2014

Many digital delta–sigma radio frequency (RF) upconverters exhibit poor performance when the carrier frequency is tuned away from the centre of the band. The offsetting of signals from the nominal carrier frequency position generates unwanted distortion products which are dominated by the image and third harmonics. It is shown that these products can be moved out of the band by the correct choice of intermediate frequency. A novel technique for shifting both the signal and the noise null to the new frequency position is described.
Lens loading approach for improving ultra‐wideband performance of spiral antennas
Authors: Elmansouri Mohamed Ali , Filipovic Dejan Sokol
Published: April 2014

A hemispherical dielectric lens is utilised to reduce the amplitude distortion in ultra‐wideband spiral antenna communication links. It is shown that a small lens action achieves a nearly constant‐aperture frequency response needed to flatten the system's transfer function when the receiving antenna has a nearly constant gain. A system fidelity factor improvement of over 26% is achieved. In addition, the lens is used to reduce the negative impact of electrical effects of shallow‐cavity backing on gain and efficiency while preserving high‐quality radiation patterns. Detailed computational and experimental analysis demonstrate a lens‐loaded spiral antenna with voltage standing wave ratio (VSWR) <1.6, axial ratio <2 dB over multi‐octave bandwidth, significant gain and efficiency improvements and fidelity factor of over 90%.
Design for Maintenance: How Kms Document Linking Decisions Affect Maintenance Effort and Use
Authors: Dennis Alan R , Samuel Binny M , McNamara Kelly
Published: April 2014

Information system maintenance is an important aspect of information system development, especially in systems that provide dynamic content, such as Web-based systems and Knowledge Management Systems (KMS). Design for Maintenance (DFM) is an approach that argues that maintenance effort should be considered during the design of information systems in addition to the usual system design considerations. This research examines how the design of links among knowledge documents in a KMS affects both their maintenance and use. We argue that providing links among knowledge documents increases the cost of maintenance because when a document changes, the documents that link to and from that document are more likely to need changes. At the same, linking knowledge documents makes it easier to locate useful knowledge and thus increases use. We examine this tension between use and maintenance using 10 years of data from a well-established KMS. Our results indicate that as the number of links among documents increases, both maintenance effort and use for these documents increase. Our analyses suggest two DFM principles for dynamic content in practice. First, knowledge coupling (i.e., linking) to documents internal to the KMS rather than sources external to the KMS better balances maintenance effort and use. Second, designing small, knowledge cohesive documents (e.g., 250-350 words) leads to the best balance between maintenance effort and use.
Turbulent flow in rib-roughened channel under the effect of Coriolis and rotational buoyancy forces
Authors: Coletti Filippo , Jacono David Lo , Cresci Irene , Arts Tony
Published: April 2014

The turbulent flow inside a rotating channel provided with transverse ribs along one wall is studied by means of two-dimensional time-resolved particle image velocimetry. The measurement set-up is mounted on the same rotating disk with the test section, allowing to obtain the same accuracy and resolution as in a non-rotating rig. The Reynolds number is 15 000, and the rotation number is 0.38. As the ribbed wall is heated, both the Coriolis force and the centrifugal force play a role in the fluid dynamics. The mean velocity fields highlight the major impact of the rotational buoyancy (characterized by a buoyancy number of 0.31) on the flow along the leading side of the duct. In particular, since the flow is directed radially outward, the near-wall layers experience significant centripetal buoyancy. The recirculation area behind the obstacles is enlarged to the point of spanning the whole inter-rib space. Also the turbulent fluctuations are significantly altered, and overall augmented, with respect to the non-buoyant case, resulting in higher turbulence levels far from the rib. On the other hand the centrifugal force has little or no impact on the flow along the trailing wall. Vortex identification, proper orthogonal decomposition, and two-point correlations are used to highlight rotational effects, and in particular to determine the dominant scales of the turbulent unsteady flow, the time-dependent behavior of the shear layer and of the recirculation bubble behind the wall-mounted obstacles, the lifetime and advection velocity of the coherent structures.
Frequency-modulated atomic force microscopy operation by imaging at the frequency shift minimum: The dip-df mode
Authors: Rode Sebastian , Schreiber Martin , Kühnle Angelika , Rahe Philipp
Published: April 2014

In frequency modulated non-contact atomic force microscopy, the change of the cantilever frequency (Δf) is used as the input signal for the topography feedback loop. Around the Δf(z) minimum, however, stable feedback operation is challenging using a standard proportional-integral-derivative (PID) feedback design due to the change of sign in the slope. When operated under liquid conditions, it is furthermore difficult to address the attractive interaction regime due to its often moderate peakedness. Additionally, the Δf signal level changes severely with time in this environment due to drift of the cantilever frequency f0 and, thus, requires constant adjustment. Here, we present an approach overcoming these obstacles by using the derivative of Δf with respect to z as the input signal for the topography feedback loop. Rather than regulating the absolute value to a preset setpoint, the slope of the Δf with respect to z is regulated to zero. This new measurement mode not only makes the minimum of the Δf(z) curve directly accessible, but it also benefits from greatly increased operation stability due to its immunity against f0 drift. We present isosurfaces of the Δf minimum acquired on the calcite CaCO3\documentclass[12pt]{minimal}\begin{document}$(10\overline{1}4)$\end{document}(101¯4) surface in liquid environment, demonstrating the capability of our method to image in the attractive tip-sample interaction regime.
Extended Krein-Adler theorem for the translationally shape invariant potentials
Authors: Gomez-Ullate David , Grandati Yves , Milson Robert
Published: April 2014

Considering successive extensions of primary translationally shape invariant potentials, we enlarge the Krein-Adler theorem to mixed chains of state adding and state-deleting Darboux-Bäcklund transformations. It allows us to establish novel bilinear Wronskian and determinantal identities for classical orthogonal polynomials.
Wide-frequency range, dynamic matching network and power system for the “Shoelace” radio frequency antenna on the Alcator C-Mod tokamak
Authors: Golfinopoulos Theodore , LaBombard Brian , Burke William , Parker Ronald R. , Parkin William , Woskov Paul
Published: April 2014

A wide-frequency range (50–300 kHz) power system has been implemented for use with a new RF antenna – the “Shoelace” antenna – built to drive coherent plasma fluctuations in the edge of the Alcator C-Mod tokamak. A custom, dynamically tunable matching network allows two commercial 1 kW, 50-Ω RF amplifiers to drive the low-impedance, inductive load presented by the antenna. This is accomplished by a discretely variable L-match network, with 81 independently selected steps available for each of the series and parallel legs of the matching configuration. A compact programmable logic device provides a control system that measures the frequency with better than 1 kHz accuracy and transitions to the correct tuning state in less than 1 ms. At least 85% of source power is dissipated in the antenna across the operational frequency range, with a minimum frequency slew rate of 1 MHz/s; the best performance is achieved in the narrower band from 80 to 150 kHz which is of interest in typical experiments. The RF frequency can be run with open-loop control, following a pre-programmed analog waveform, or phase-locked to track a plasma fluctuation diagnostic signal in real time with programmable phase delay; the amplitude control is always open-loop. The control waveforms and phase delay are programmed remotely. These tools have enabled first-of-a-kind measurements of the tokamak edge plasma system response in the frequency range and at the wave number at which coherent fluctuations regulate heat and particle transport through the plasma boundary.
Quadrupole terms in the Maxwell equations: Debye-Hückel theory in quadrupolarizable solvent and self-salting-out of electrolytes
Authors: Slavchov Radomir I.
Published: April 2014

If the molecules of a given solvent possess significant quadrupolar moment, the macroscopic Maxwell equations must involve the contribution of the density of the quadrupolar moment to the electric displacement field. This modifies the Poisson-Boltzmann equation and all consequences from it. In this work, the structure of the diffuse atmosphere around an ion dissolved in quadrupolarizable medium is analyzed by solving the quadrupolar variant of the Coulomb-Ampere's law of electrostatics. The results are compared to the classical Debye-Hückel theory. The quadrupolar version of the Debye-Hückel potential of a point charge is finite even in r = 0. The ion-quadrupole interaction yields a significant expansion of the diffuse atmosphere of the ion and, thus, it decreases the Debye-Hückel energy. In addition, since the dielectric permittivity of the electrolyte solutions depends strongly on concentration, the Born energy of the dissolved ions alters with concentration, which has a considerable contribution to the activity coefficient γ± known as the self-salting-out effect. The quadrupolarizability of the medium damps strongly the self-salting-out of the electrolyte, and thus it affects additionally γ±. Comparison with experimental data for γ± for various electrolytes allows for the estimation of the quadrupolar length of water: LQ ≈ 2 Å, in good agreement with previous assessments. The effect of quadrupolarizability is especially important in non-aqueous solutions. Data for the activity of NaBr in methanol is used to determine the quadrupolarizability of methanol with good accuracy.
van der Waals density functionals built upon the electron-gas tradition: Facing the challenge of competing interactions
Authors: Berland Kristian , Arter Calvin A. , Cooper Valentino R. , Lee Kyuho , Lundqvist Bengt I. , Schröder Elsebeth , Thonhauser T. , Hyldgaard Per
Published: April 2014

The theoretical description of sparse matter attracts much interest, in particular for those ground-state properties that can be described by density functional theory. One proposed approach, the van der Waals density functional (vdW-DF) method, rests on strong physical foundations and offers simple yet accurate and robust functionals. A very recent functional within this method called vdW-DF-cx [K. Berland and P. Hyldgaard, Phys. Rev. B 89, 035412 (2014)] stands out in its attempt to use an exchange energy derived from the same plasmon-based theory from which the nonlocal correlation energy was derived. Encouraged by its good performance for solids, layered materials, and aromatic molecules, we apply it to several systems that are characterized by competing interactions. These include the ferroelectric response in PbTiO3, the adsorption of small molecules within metal-organic frameworks, the graphite/diamond phase transition, and the adsorption of an aromatic-molecule on the Ag(111) surface. Our results indicate that vdW-DF-cx is overall well suited to tackle these challenging systems. In addition to being a competitive density functional for sparse matter, the vdW-DF-cx construction presents a more robust general-purpose functional that could be applied to a range of materials problems with a variety of competing interactions.
Two-level system in spin baths: Non-adiabatic dynamics and heat transport
Authors: Segal Dvira
Published: April 2014

We study the non-adiabatic dynamics of a two-state subsystem in a bath of independent spins using the non-interacting blip approximation, and derive an exact analytic expression for the relevant memory kernel. We show that in the thermodynamic limit, when the subsystem-bath coupling is diluted (uniformly) over many (infinite) degrees of freedom, our expression reduces to known results, corresponding to the harmonic bath with an effective, temperature-dependent, spectral density function. We then proceed and study the heat current characteristics in the out-of-equilibrium spin-spin-bath model, with a two-state subsystem bridging two thermal spin-baths of different temperatures. We compare the behavior of this model to the case of a spin connecting boson baths, and demonstrate pronounced qualitative differences between the two models. Specifically, we focus on the development of the thermal diode effect, and show that the spin-spin-bath model cannot support it at weak (subsystem-bath) coupling, while in the intermediate-strong coupling regime its rectifying performance outplays the spin-boson model.
High-precision instrument for measuring the surface tension, viscosity and surface viscoelasticity of liquids using ripplon surface laser-light scattering with tunable wavelength selection
Authors: Nishimura Yu , Hasegawa Akinori , Nagasaka Yuji
Published: April 2014

Here we describe our new high-precision instrument that simultaneously measures the surface tension, viscosity, and surface viscoelasticity of liquids. The instrument works on the ripplon surface-laser light scattering principle and operates with an automatically tunable selection of ripplon wavelength from 4 to 1500 μm, which corresponds to the frequency range of observing surface phenomena from approximately 400 Hz to 3 MHz in the case of water. The heterodyne technique instrument uses a reference laser beam which intersects at an arbitrarily adjustable angle with a vertically directed probing beam. For the determination of the wavelength of selected ripplons we substituted with the interference fringe spacing, measured using a high-resolution beam profiler. To extract reliable surface tension and viscosity data from the experimentally obtained spectrum shape for a selected wavelength of ripplon, we developed an algorithm to calculate the exact solution of the dispersion equation. The uncertainties of surface tension and viscosity measurement were confirmed through the measurement of seven pure Newtonian liquids at 25 °C measured with the selected wavelength of ripplon from 40 μm to 467 μm. To verify the genuine capability of the tunable wavelength selection of ripplon, we measured the surface elasticity of soluble surface molecular layers spread on pentanoic acid solutions.
Development of multicomponent hybrid density functional theory with polarizable continuum model for the analysis of nuclear quantum effect and solvent effect on NMR chemical shift
Authors: Kanematsu Yusuke , Tachikawa Masanori
Published: April 2014

We have developed the multicomponent hybrid density functional theory [MC_(HF+DFT)] method with polarizable continuum model (PCM) for the analysis of molecular properties including both nuclear quantum effect and solvent effect. The chemical shifts and H/D isotope shifts of the picolinic acid N-oxide (PANO) molecule in chloroform and acetonitrile solvents are applied by B3LYP electron exchange-correlation functional for our MC_(HF+DFT) method with PCM (MC_B3LYP/PCM). Our MC_B3LYP/PCM results for PANO are in reasonable agreement with the corresponding experimental chemical shifts and isotope shifts. We further investigated the applicability of our method for acetylacetone in several solvents.