bluuebunny/crossref_metadata_2025 huggingface dataset:
Jacobian Conjecture and semi-algebraic maps
Authors: FERNANDES ALEXANDRE , MAQUERA CARLOS , VENATO–SANTOS JEAN
Published: June 2014

LetF:${\mathbb R}$n→${\mathbb R}$nbe a polynomial local diffeomorphism and letSFdenote the set of not proper points ofF. The Jelonek's real Jacobian Conjecture states that if codim(SF) ≥ 2, thenFis bijective. In this work we prove a weak version of such Conjecture, but for more general maps than polynomial, namely: the semi-algebraic maps.
Diurnal cortisol rhythms in youth from risky families: Effects of cumulative risk exposure and variation in the serotonin transporter linked polymorphic region gene
Authors: Willner Cynthia J. , Morris Pamela A. , McCoy Dana Charles , Adam Emma K.
Published: June 2014

Building on research on cumulative risk and psychopathology, this study examines how cumulative risk exposure is associated with altered diurnal cortisol rhythms in an ethnically diverse, low-income sample of youth. In addition, consistent with a diathesis-stress perspective, this study explores whether the effect of environmental risk is moderated by allelic variation in the serotonin transporter linked polymorphic region (5-HTTLPR) gene. Results show that youth with greater cumulative risk exposure had flatter diurnal cortisol slopes, regardless of5-HTTLPRgenotype. However, the association of cumulative risk with average cortisol output (area under the curve [AUC]) was moderated by the5-HTTLPRgenotype. Among youth homozygous for the long allele, greater cumulative risk exposure was associated with lower cortisol AUC, driven by significant reductions in cortisol levels at waking. In contrast, there was a trend-level association between greater cumulative risk and higher cortisol AUC among youth carrying the short allele, driven by a trend-level increase in bedtime cortisol levels. Findings are discussed with regard to the relevance of dysregulated diurnal cortisol rhythms for the development of psychopathology and the implications of genetically mediated differences in psychophysiological adaptations to stress.
Associations between trajectories of perceived racial discrimination and psychological symptoms among African American adolescents
Authors: Smith-Bynum Mia A. , Lambert Sharon F. , English Devin , Ialongo Nicholas S.
Published: June 2014

Many African American adolescents experience racial discrimination, with adverse consequences; however, stability and change in these experiences over time have not been examined. We examined longitudinal patterns of perceived racial discrimination assessed in Grades 7–10 and how these discrimination trajectories related to patterns of change in depressive and anxious symptoms and aggressive behaviors assessed over the same 4-year period. Growth mixture modeling performed on a community epidemiologically defined sample of urban African American adolescents (n= 504) revealed three trajectories of discrimination: increasing, decreasing, and stable low. As predicted, African American boys were more frequent targets for racial discrimination as they aged, and they were more likely to be in the increasing group. The results of parallel process growth mixture modeling revealed that youth in the increasing racial discrimination group were four times more likely to be in an increasing depression trajectory than were youth in the low stable discrimination trajectory. Though youth in the increasing racial discrimination group were nearly twice as likely to be in the high aggression trajectory, results were not statistically significant. These results indicate an association between variation in the growth of perceived racial discrimination and youth behavior and psychological well-being over the adolescent years.
An insight into the autonomic and haemodynamic mechanisms underlying reflex syncope in children and adolescents: a multiparametric analysis
Authors: Laranjo Sérgio , Tavares Cristiano , Oliveira Mário , Trigo Conceição , Pinto Fátima , Rocha Isabel
Published: June 2014

Around 15% of children and adolescents experience at least one episode of syncope until adulthood. Excluding cardiac disease, the majority of syncopes are of reflex origin and benign in nature. In this situation, a tilt test is conducted to reproduce symptoms and to evaluate cardiovascular adaptations to orthostatism, but its mechanisms are not yet well defined. Here, we investigated haemodynamics and autonomic activity during tilt in young patients. Patients (n=113) with unexplained syncope were enrolled. Tilt followed a standard protocol without provocative agents. A positive response (fainters) was defined as a sudden development of syncope or presyncope associated with hypotension, bradycardia, or both. Haemodynamic parameters, autonomic activity, and baroreflex sensibility were evaluated. Data were analysed on baseline; immediately after tilting; on tilt adaptation; before fainting or before tilt-down for non-fainters; and on tilt-down. A total of 45 patients experienced syncope after a mean time of 18 minutes. During tilting up, fainters showed lower blood pressure and peripheral resistance values, which decreased progressively with time together with baroreflex sensibility. Sympathetic tone increased massively along time till syncope. No changes in cardiac output and heart rate were observed. Results show a strong effort of the autonomic nervous system to adapt to orthostatic stress through different magnitudes of sympathetic output, which was maximal before syncope without apparent modifications of parasympathetic tone. These changes suggest an imbalance between both branches of the autonomic nervous system, not enabling a time-progressive adaptation and leading the subject to faint.
Rapid spontaneous closure and remodelling of a medium-sized symptomatic congenital coronary artery fistula in an infant before the age of 3 months
Authors: Lu Wen-Hsien , Huang Ta-Cheng , Hsieh Kai-Sheng
Published: June 2014

It is controversial to observe or close symptomatic congenital coronary artery fistula in infants. We herein describe a medium-sized symptomatic congenital coronary artery fistula that underwent rapid spontaneous closure in an infant aged <3 months.
Lurasidone for the treatment of depressive symptoms in schizophrenia: analysis of 4 pooled, 6-week, placebo-controlled studies
Authors: Nasrallah Henry A. , Cucchiaro Josephine B. , Mao Yongcai , Pikalov Andrei A. , Loebel Antony D.
Published: June 2014

Objective

Depressive symptoms are common in schizophrenia and can worsen outcomes and increase suicide risk. Lurasidone is an atypical antipsychotic agent indicated for the treatment of schizophrenia and for the treatment of major depressive episodes associated with bipolar I disorder. This post hoc analysis evaluated the effect of lurasidone on depressive symptoms in patients with schizophrenia.

Methods

Patient-level data were pooled from 4 similarly designed, double-blind, placebo-controlled, 6-week registration studies of lurasidone (40–160 mg/d) in adult patients with an acute exacerbation of schizophrenia. Changes in depressive symptoms, measured by the Montgomery–Åsberg Depression Rating Scale (MADRS), were analyzed for the overall sample and for subgroups of patients stratified by baseline MADRS scores.

Results

MADRS assessments at baseline and endpoint (day 42 or last observation carried forward [LOCF]) were available for 1330 patients. Patients receiving lurasidone experienced significantly greater decreases in MADRS score (–2.8, least-squares [LS] mean change, LOCF) compared with patients receiving placebo (–1.4,P< .001, effect size 0.24). Analysis of change in MADRS score (LOCF) by baseline symptom severity (MADRS score of ≥12, ≥14, ≥16, ≥18) showed significantly greater improvement for lurasidone-treated patients across all severity groups; effect sizes ranged from 0.25 to 0.34. Among patients with a baseline MADRS score of ≥12, depressive symptom remission (defined as MADRS score <10 at LOCF endpoint) was attained by 45.0% of lurasidone-treated patients and 36.3% of patients receiving placebo (P< .05).

Conclusions

In a pooled analysis of short-term, placebo-controlled studies, lurasidone significantly improved depressive symptoms in patients with schizophrenia.
Validation of a BMI cut-off point to predict an adverse cardiometabolic profile with adiposity measurements by dual-energy X-ray absorptiometry in Guatemalan children
Authors: Redondo Olga , Villamor Eduardo , Valdés Javiera , Bilal Usama , Caballero Benjamín , Roche Dina , Kroker Fernanda , Ramírez-Zea Manuel , Franco Manuel
Published: June 2014

Objective

To identify a body fat percentage (%BF) threshold related to an adverse cardiometabolic profile and its surrogate BMI cut-off point.

Design

Cross-sectional study.

Setting

Two public schools in poor urban areas on the outskirts of Guatemala City.

Subjects

A convenience sample of ninety-three healthy, prepubertal, Ladino children (aged 7–12 years).

Results

Spearman correlations of cardiometabolic parameters were higher with %BF than with BMI-for-ageZ-score. BMI-for-ageZ-score and %BF were highly correlated (r=0·84). The %BF threshold that maximized sensitivity and specificity for predicting an adverse cardiometabolic profile (elevated homeostasis model assessment–insulin resistance index and/or total cholesterol:HDL-cholesterol ratio) according to receiver operating characteristic curve analysis was 36 %. The BMI-for-ageZ-score cut-off point that maximized the prediction of BF ≥ 36 % by the same procedure was 1·5. The area under the curve (AUC) for %BF and for BMI data showed excellent accuracy to predict an adverse cardiometabolic profile (AUC 0·93 (sd0·04)) and excess adiposity (AUC 0·95 (sd0·02)).

Conclusions

Since BMI standards have limitations in screening for adiposity, specific cut-off points based on ethnic-/sex- and age-specific %BF thresholds are needed to better predict an adverse cardiometabolic profile.
TAKING POSTRACIALISM SERIOUSLY
Authors: Taylor Paul C.
Published: June 2014

This essay reconsiders the prospects for postracialist discourse. Critics tend not to take seriously enough the strongest case that can be made for viewing contemporary U.S. racial politics through the postracial lens. As a result, some important criticisms—the ones that survive postracialism’s reformulation in these stronger terms—have yet to be fully developed. It is important to develop a critique of the strongest form of postracialism, because this form of the view shares, or exemplifies, certain problems in garden-variety liberal antiracisms. Clarifying these problems in the more extreme conceptual environment of postracialism may help clarify their implications for the much more widespread commitments of mainstream post-civil rights thinking.
Design of asymmetrically slotted hexagonal patch antenna for high-gain UWB applications
Authors: Krishna Raghupatruni Venkat Siva Ram , Kumar Raj , Kushwaha Nagendra
Published: June 2014

A compact slot antenna for high-gain ultra wideband applications is presented. The slot is asymmetrically cut in the ground plane and is a combination of two rectangles. A hexagonal patch with two stepped coplanar waveguide-feed is used to excite the slot. The capacitive reactance of the hexagonal patch is neutralized by the inductive reactance created by the asymmetric slot and results into wider impedance matching. The measured impedance bandwidth of the proposed antenna is 11.85 GHz (2.9–14.75 GHz). The radiation patterns of the proposed antenna are found to be omni-directional in the H-plane and bi-directional in the E-plane. To enhance the gain of the antenna, a compact three-layer frequency selective surface (FSS) is used as a reflector. The overall thickness of the FSS is 3.5 mm. There is 4–5 dBi improvement in antenna gain after application of the FSS. The measured and simulated results are in good agreement.
Comprehensive RNA-Seq transcriptomic profiling across 11 organs, 4 ages, and 2 sexes of Fischer 344 rats
Authors: Yu Ying , Zhao Chen , Su Zhenqiang , Wang Charles , Fuscoe James C , Tong Weida , Shi Leming
Published: June 2014

The rat is used extensively by the pharmaceutical, regulatory, and academic communities for safety assessment of drugs and chemicals and for studying human diseases; however, its transcriptome has not been well studied. As part of the SEQC (i.e., MAQC-III) consortium efforts, a comprehensive RNA-Seq data set was constructed using 320 RNA samples isolated from 10 organs (adrenal gland, brain, heart, kidney, liver, lung, muscle, spleen, thymus, and testes or uterus) from both sexes of Fischer 344 rats across four ages (2-, 6-, 21-, and 104-week-old) with four biological replicates for each of the 80 sample groups (organ-sex-age). With the Ribo-Zero rRNA removal and Illumina RNA-Seq protocols, 41 million 50 bp single-end reads were generated per sample, yielding a total of 13.4 billion reads. This data set could be used to identify and validate new rat genes and transcripts, develop a more comprehensive rat transcriptome annotation system, identify novel gene regulatory networks related to tissue specific gene expression and development, and discover genes responsible for disease and drug toxicity and efficacy.
Tree of Sex: A database of sexual systems
Authors:   The Tree of Sex Consortium, Ashman Tia-Lynn , Bachtrog Doris , Blackmon Heath , Goldberg Emma E , Hahn Matthew W , Kirkpatrick Mark , Kitano Jun , Mank Judith E , Mayrose Itay , Ming Ray , Otto Sarah P , Peichel Catherine L , Pennell Matthew W , Perrin Nicolas , Ross Laura , Valenzuela Nicole , Vamosi Jana C
Published: June 2014

The vast majority of eukaryotic organisms reproduce sexually, yet the nature of the sexual system and the mechanism of sex determination often vary remarkably, even among closely related species. Some species of animals and plants change sex across their lifespan, some contain hermaphrodites as well as males and females, some determine sex with highly differentiated chromosomes, while others determine sex according to their environment. Testing evolutionary hypotheses regarding the causes and consequences of this diversity requires interspecific data placed in a phylogenetic context. Such comparative studies have been hampered by the lack of accessible data listing sexual systems and sex determination mechanisms across the eukaryotic tree of life. Here, we describe a database developed to facilitate access to sexual system and sex chromosome information, with data on sexual systems from 11,038 plant, 705 fish, 173 amphibian, 593 non-avian reptilian, 195 avian, 479 mammalian, and 11,556 invertebrate species.
Up-regulating pyocyanin production by amino acid addition for early electrochemical identification of Pseudomonas aeruginosa
Authors: Sismaet Hunter J. , Webster Thaddaeus A. , Goluch Edgar D.
Published: June 2014

A simple and rapid electrochemical detection method for Pseudomonas aeruginosa is demonstrated using amino acids as up-regulatory molecules for pyocyanin production.
Quantification and pharmacokinetics of astragaloside II in rats by rapid liquid chromatography-tandem mass spectrometry
Authors: Qu Haijun , Sun Meijuan , Cao Yu , Wang Longyuan , Han Zhiwu
Published: June 2014

Mean plasma concentration–time profiles of AST II determined by the LC-MS/MS method after intravenous and oral administration of AST II to rats. The oral absolute bioavailability (F) of AST II in rats was calculated to be 0.79 ± 0.16%, suggesting its poor absorption and/or strong metabolismin vivo.
Water-soluble d-glucuronic acid coated ultrasmall mixed Ln/Mn (Ln = Gd and Dy) oxide nanoparticles and their application to magnetic resonance imaging
Authors: Bony Badrul Alam , Baeck Jong Su , Chang Yongmin , Bae Ji Eun , Chae Kwon Seok , Lee Gang Ho
Published: June 2014

Mixed (A) Gd/Mn and (B) Dy/Mn oxide nanoparticles are confirmed to be potential T1 and/or T2 MRI contrast agents, respectively.
The causality principle in the reconstruction of sparse NMR spectra
Authors: Mayzel M. , Kazimierczuk K. , Orekhov V. Yu.
Published: June 2014

Improved quality of NMR spectra reconstruction from non-uniformly sampled data by harnessing the causality principle and prior knowledge about the signal phase.
A femtogram level competitive immunoassay of mercury(ii) based on surface-enhanced Raman spectroscopy
Authors: Wang Yuzhen , Chen Shuai , Wei Chao , Xu Minmin , Yao Jianlin , Li Yuan , Deng Anping , Gu Renao
Published: June 2014

A femtogram level and specific surface enhanced Raman spectroscopy (SERS) based competitive immunoassay was developed to detect Hg(ii) in aqueous solution.
Assembly of binary, ternary and quaternary compound semiconductor nanorods: From local to device scale ordering influenced by surface charge
Authors: Ryan Kevin M. , Singh Shalini , Liu Pai , Singh Ajay
Published: June 2014

In this article we outline the assembly of binary, ternary and quaternary nanorods using three separate protocols: (a) droplet based assembly, (b) assembly in a vial, (c) electrophoretic deposition. The rods are the important photoabsorbers CdS, CdSexS1−x, CuInxGa1−xS, and Cu2ZnSnS4.
Tailoring bismuth telluride nanostructures using a scalable sintering process and their thermoelectric properties
Authors: Anandan P. , Omprakash M. , Azhagurajan M. , Arivanandhan M. , Rajan Babu D. , Koyama T. , Hayakawa Y.
Published: June 2014

The size and phase of bismuth telluride nanocrystals were tailored using a sintering process, to enhance their thermoelectric properties.
Exploration of the polymorph landscape for 1,1,4,4-tetraphenyl-1,3-butadiene
Authors: Bacchi A. , Brillante A. , Crocco D. , Chierotti M. R. , Della Valle R. G. , Girlando A. , Masino M. , Pelagatti P. , Venuti E.
Published: June 2014

The solid state behaviour of 1,1,4,4-tetraphenyl-1,3-butadiene (TPB), a well-known blue luminescent molecule, is presented. The crystal structures of four polymorphs and one solvate form are discussed and the experimental occurrence of the four polymorphs is rationalized.
Gas-surface reactions of nitrate radicals with vinyl-terminated self-assembled monolayers
Authors: Zhang Yafen , Chapleski Robert C. , Lu Jessica W. , Rockhold Thomas H. , Troya Diego , Morris John R.
Published: June 2014

Interfacial reactions between gas-phase nitrate radicals, a key nighttime atmospheric oxidant, and a model unsaturated organic surface have been investigated to determine the reaction kinetics and probable reaction mechanism.
A new exchange–correlation functional free of delocalization and static correlation errors
Authors: Liu Yu , Wu Jianzhong
Published: June 2014

A combination of weighted density approximation and classical mapping leads to a new exchange–correlation energy free of delocalization and static correlation errors in Kohn–Sham density functional theory.
Solvent effects on the photochemistry of 4-aminoimidazole-5-carbonitrile, a prebiotically plausible precursor of purines
Authors: Szabla Rafał , Šponer Judit E. , Šponer Jiří , Sobolewski Andrzej L. , Góra Robert W.
Published: June 2014

Ab initio studies elucidate the molecular mechanisms underlying the photostability of a prebiotically plausible precursor of purine nucleotides, indicating the importance of charge transfer to solvent processes.
Structure and magnetic properties of (Fe2O3)n clusters (n = 1–5)
Authors: Erlebach A. , Hühn C. , Jana R. , Sierka M.
Published: June 2014

Global minimum structures of (Fe2O3)n clusters (n = 1–5) determined for the first time in this size range show weak dependence of the structure and relative stabilities of different isomers on their magnetic states.
Discrimination of the mechanism of CH4formation in Fischer–Tropsch synthesis on Co catalysts: a combined approach of DFT, kinetic isotope effects and kinetic analysis
Authors: Qi Yanying , Yang Jia , Duan Xuezhi , Zhu Yi-An , Chen De , Holmen Anders
Published: June 2014

The mechanism of CH4formation during Fischer–Tropsch synthesis on cobalt has been studied.
Fe@CNT-monoliths for the conversion of carbon dioxide to hydrocarbons: structural characterisation and Fischer–Tropsch reactivity investigations
Authors: Minett Daniel R. , O'Byrne Justin P. , Pascu Sofia I. , Plucinski Pawel K. , Owen Rhodri E. , Jones Matthew D. , Mattia Davide
Published: June 2014

High carbon dioxide conversion to hydrocarbons using iron nanoparticle (Fe@CNT) catalysts supported on cordierite monoliths.
Efficient one-pot synthesis of propargylamines catalysed by gold nanocrystals stabilized on montmorillonite
Authors: Borah Bibek Jyoti , Borah Subrat Jyoti , Saikia Kokil , Dutta Dipak Kumar
Published: June 2014

Size selective Au0-nanoparticles were generatedin situin the nanopores of montmorillonite and applied in the one-pot, three-component coupling of an aldehyde, an amine and an alkyne to synthesize propargylamines.
BR2BodPR2: highly fluorescent alternatives to PPh3and PhPCy2
Authors: Davies Laura H. , Harrington Ross W. , Clegg William , Higham Lee J.
Published: June 2014

The syntheses of highly fluorescent analogues of PPh3and PhPCy2based on the Bodipy chromophore are described.
One-pot controlled synthesis of sea-urchin shaped Bi2S3/CdS hierarchical heterostructures with excellent visible light photocatalytic activity
Authors: Shi Yunhan , Chen Yajie , Tian Guohui , Fu Honggang , Pan Kai , Zhou Juan , Yan Haijing
Published: June 2014

Sea-urchin shaped Bi2S3/CdS hierarchical heterostructures were synthesized via a one-pot solvothermal route, which exhibited enhanced photocatalytic activity.
Modulating reactivity in iridium bis(N-heterocyclic carbene) complexes: influence of ring size on E–H bond activation chemistry
Authors: Phillips Nicholas , Tang Christina Y. , Tirfoin Rémi , Kelly Michael J. , Thompson Amber L. , Gutmann Matthias J. , Aldridge Simon
Published: June 2014

Critical influence of NHC ring size: highly labile [Ir(5-Mes)2(H)2]+can only be studied by trapping experiments, while [Ir(6-Mes)2(H)2]+and [Ir(6-Xyl)2(H)2]+are air/moisture stable.
Hierarchical electrospun nanofibers for energy harvesting, production and environmental remediation
Authors: Kumar Palaniswamy Suresh , Sundaramurthy Jayaraman , Sundarrajan Subramanian , Babu Veluru Jagadeesh , Singh Gurdev , Allakhverdiev Suleyman I. , Ramakrishna Seeram
Published: June 2014

Recent developments in the synthesis of electrospun nanomaterials and their potential prospects in energy and environmental applications are discussed in detail.
A computational study of potential molecular switches that exploit Baird's rule on excited-state aromaticity and antiaromaticity
Authors: Löfås H. , Jahn B. O. , Wärnå J. , Emanuelsson R. , Ahuja R. , Grigoriev A. , Ottosson H.
Published: June 2014

A series of tentative single-molecule conductance switches which could be triggered by light were examined by computational means using density functional theory (DFT) with non-equilibrium Green's functions (NEGF). The switches exploit the reversal in electron counting rules for aromaticity and antiaromaticity upon excitation from the electronic ground state (S0) to the lowest ππ* excited singlet and triplet states (S1 or T1), as described by Hückel's and Baird's rules, respectively. Four different switches and one antifuse were designed which rely on various photoreactions that either lead from the OFF to the ON states (switches 1, 2 and 4, and antifuse 5) or from the ON to the OFF state (switch 3). The highest and lowest ideal calculated switching ratios are 1175 and 5, respectively, observed for switches 1 and 4. Increased thermal stability of the 1-ON isomer is achieved by benzannulation (switch 1B-OFF/ON). The effects of constrained electrode–electrode distances on activation energies for thermal hydrogen back-transfer from 1-ON to 1-OFF and the relative energies of 1-ON and 1-OFF at constrained geometries were also studied. The switching ratio is strongly distance-dependent as revealed for 1B-ON/OFF where it equals 711 and 148 when the ON and OFF isomers are calculated in electrode gaps with distances confined to either that of the OFF isomer or to that of the ON isomer, respectively.
Neuroprotective effects of dietary supplement Kang-fu-ling against high-power microwave through antioxidant action
Authors: Hu Shaohua , Peng Ruiyun , Wang Changzhen , Wang Shuiming , Gao Yabing , Dong Ji , Zhou Hongmei , Su Zhentao , Qiao Shanyi , Zhang Shouguo , Wang Lin , Wen Xiaoxue
Published: June 2014

KFL displays a protective effect against HPM-induced cognitive impairment and histopathological changes by ameliorating oxidative stress via the Nrf2-ARE signaling pathway.
Individually addressable arrays of replica microbial cultures enabled by splitting SlipChips
Authors: Ma Liang , Datta Sujit S. , Karymov Mikhail A. , Pan Qichao , Begolo Stefano , Ismagilov Rustem F.
Published: June 2014

This paper describes a microfluidic device to create arrays of individually addressable replica microbial culturesviasplitting, which can be applied for genetically targeted cultivation of microbes.
Evaluation of functional groups as acetyl-lysine mimetics for BET bromodomain inhibition
Authors: Sharp Phillip P. , Garnier Jean-Marc , Huang David C. S. , Burns Christopher J.
Published: June 2014

This work provides new insights into a range of acetyl-lysine mimetics as BET bromodomain inhibitors.
Hyperaccumulation of zinc by Noccaea caerulescens results in a cascade of stress responses and changes in the elemental profile
Authors: Foroughi Siavash , Baker Alan J. M. , Roessner Ute , Johnson Alexander A. T. , Bacic Antony , Callahan Damien L.
Published: June 2014

Noccaea caerulescens can accumulate more than 2% Zn in the leaves without showing any outwards signs of toxicity however a myriad of elemental and metabolite changes occur at these concentrations.
Nitronyl and imino nitroxide free radicals as precursors of magnetic phthalocyanine and porphyrin building blocks
Authors: Önal Emel , Yerli Yusuf , Cosut Bunyemin , Pilet Guillaume , Ahsen Vefa , Luneau Dominique , Hirel Catherine
Published: June 2014

Phthalonitrile and benzaldehyde bearing α-nitronyl and α-imino nitroxide free radicals have been synthesized as precursors of nitroxide substituted phthalocyanine and porphyrin macrocycle.
Enantioselective palladium catalyzed conjugate additions of ortho-substituted arylboronic acids to β,β-disubstituted cyclic enones: total synthesis of herbertenediol, enokipodin A and enokipodin B
Authors: Buter Jeffrey , Moezelaar Renée , Minnaard Adriaan J.
Published: June 2014

Palladium catalyzed asymmetric conjugate addition of ortho-substituted arylboronic acids to cyclic enones and its application in natural product synthesis.
Ozonation of methylenecyclopropanes
Authors: Sang Rui , Tang Xiang-Ying , Shi Min
Published: June 2014

Ozonation of methylenecyclopropanes bearinggem-disubstituted electron-withdrawing groups (EWG) gave ring-opened oxidative products in moderate to good yields.
Efficient and regioselective synthesis of bicyclic pyrrolidones or bicyclic pyridones by cyclocondensation of heterocyclic ketene aminals with nitro-phenylpropiolate
Authors: Fan Juan , Yang Qin-Yi , He Guo-Jin , Xie Xiao-Guang , Zhu Hong-You , Jin Yi , Lin Jun
Published: June 2014

HKAs underwent nucleophilic addition to the α, β-unsaturated CC of nitro-phenylpropiolate, obtaining a series of novel bicyclic pyrrolidones or bicyclic pyridones, whereas the opposite regioselectivity was observed.
Effect of selective solvent on the aggregate behavior of the mixed Langmuir monolayers of PS-b-PEO and PS-b-PMMA
Authors: Wang Zhuang , Wen Gangyao , Zhao Fengyang , Huang Changchun , Wang Xiaoqun , Shi Tongfei , Li Hongfei
Published: June 2014

An interesting way to control morphology evolution in the mixed LB films was performed by mainly using a selective spreading solvent. Furthermore, a peculiar hysteresis phenomenon in the polymeric Langmuir monolayers is reported.
Tunable photonic crystals with partial bandgaps from blue phase colloidal crystals and dielectric-doped blue phases
Authors: Stimulak Mitja , Ravnik Miha
Published: June 2014

Tunable photonic crystals from dielectric doped blue phases are demonstrated, based on the idea of combining multiple soft matter components with different symmetries into one photonic material.
The position of hydrophobic residues tunes peptide self-assembly
Authors: Bortolini Christian , Liu Lei , Gronewold Thomas M. A. , Wang Chen , Besenbacher Flemming , Dong Mingdong
Published: June 2014

The variation in the positions of hydrophobic residues within a peptide sequence can tune the self-assembly.
Environmentally benign magnetic chitosan/Fe3O4 composites as reductant and stabilizer for anchoring Au NPs and their catalytic reduction of 4-nitrophenol
Authors: Qiu Yunfeng , Ma Zhuo , Hu PingAn
Published: June 2014

Environmentally benign magnetic Au NPs/chitosan/Fe3O4 composites: preparation and their catalytic reduction of 4-nitrophenol.
Optimization of the carrier concentration in phase-separated half-Heusler compounds
Authors: Krez Julia , Schmitt Jennifer , Jeffrey Snyder G. , Felser Claudia , Hermes Wilfried , Schwind Markus
Published: June 2014

Phase separated half-Heusler compounds and the application of an average effective mass model to optimize the carrier concentration.
Structural insights into yeast histone chaperone Hif1: a scaffold protein recruiting protein complexes to core histones
Authors: Liu Hejun , Zhang Mengying , He Wei , Zhu Zhongliang , Teng Maikun , Gao Yongxiang , Niu Liwen
Published: June 2014

Yeast Hif1 [Hat1 (histone acetyltransferase 1)-interacting factor], a homologue of human NASP (nuclear autoantigenic sperm protein), is a histone chaperone that is involved in various protein complexes which modify histones during telomeric silencing and chromatin reassembly. For elucidating the structural basis of Hif1, in the present paper we demonstrate the crystal structure of Hif1 consisting of a superhelixed TPR (tetratricopeptide repeat) domain and an extended acid loop covering the rear of TPR domain, which represent typical characteristics of SHNi-TPR [Sim3 (start independent of mitosis 3)-Hif1-NASP interrupted TPR] proteins. Our binding assay indicates that Hif1 could bind to the histone octamer via histones H3 and H4. The acid loop is shown to be crucial for the binding of histones and may also change the conformation of the TPR groove. By binding to the core histone complex Hif1 may recruit functional protein complexes to modify histones during chromatin reassembly.
Post-transcriptional regulation of the human reduced folate carrier as a novel adaptive mechanism in response to folate excess or deficiency
Authors: Hou Zhanjun , Orr Steve , Matherly Larry H.
Published: June 2014

The RFC (reduced folate carrier) is the principal mechanism by which folates and clinically used antifolates are delivered to mammalian cells. hRFC (human RFC) is subject to complex transcriptional controls and exists as homo-oligomer. To explore the post-transcriptional regulation of hRFC by exogenous folates, hRFC-null HeLa cells were stably transfected with hRFC under control of a constitutive promoter. hRFC transcripts and the total membrane protein increased with increasing LCV [(6R,S)5-formyl tetrahydrofolate (leucovorin)] with a maximum at 20 nM LCV, attributable to reduced turnover of hRFC transcripts. hRFC homo-oligomerization was unaffected by increasing LCV. Cell surface hRFC paralleled [3H]methotrexate transport and increased from 0.5 to 2 nM LCV, and then decreased (~2-fold) with increasing LCV up to 20 nM. hRFC was localized to the cell surface at low LCV concentrations (0.5–1.5 nM). However, at higher LCV concentrations, significant intracellular hRFC was localized to the ER (endoplasmic reticulum), such that at 20 nM LCV, intracellular hRFC was predominated. Our results demonstrate a novel post-transcriptional regulation of hRFC involving: (i) increased hRFC transcripts and proteins, accompanying increased extracellular folates, attributable to differences in hRFC transcript stabilities; and (ii) increased retention of hRFC in the ER under conditions of folate excess, because of impaired intracellular trafficking and plasma membrane targeting.
Personal security in travel by public transport: the role of traveller information and associated technologies
Authors: Beecroft Mark , Pangbourne Kate
Published: June 2014

This study focuses on the role of traveller information and associated technologies in supporting personal security in travel by public transport. It reports research undertaken via a workshop involving SWOT analysis and scenario planning and a series of expert interviews. These research activities created a baseline understanding of how personal security issues are currently addressed, and identified potential future issues and how they might be tackled. Information is a major source of confidence and reassurance when travelling and can greatly support perceptions of personal security in travel. There have been significant advances in recent years in the quantity of information available and in delivery mechanisms. However, significant issues remain, particularly in terms of information quality, its representation in the public realm and its ability to support the needs of users. The differences in the relationship between information requirements and related commercial imperatives is shown to be perhaps the critical factor in determining the alternative pathways and associated services, technologies and personal security outcomes which emerge under the different scenarios.
Dielectric loaded antipodal curvilinear tapered slot antenna based on substrate integrated waveguide
Authors: Zou Xiong , Tong Chuang‐Ming , Bao Jun‐Song , Sun Jia‐Jia , Li Chang‐Ze
Published: June 2014

A dielectric loaded antipodal curvilinear tapered slot antenna based on substrate integrated waveguide is proposed in this study. High gain, low side lobe level and low reflectance could be obtained by choosing of the length and width of slot correctly. The loaded dielectric slab in front of the slot can result in a narrower beamwidth both in the H‐plane and in the E‐plane as a dielectric guiding structure. A two‐dimensional antenna array, formed by a non‐planar four‐way power divider, has a broad bandwidth ranging from 9.5 to 12 GHz and high gains over 12 dBi, which can be widely applied to microwave and millimetre‐wave systems.
Frequency‐reconfigurable single‐ and dual‐band designs of a multi‐mode microstrip antenna
Authors: Al‐Zayed Ayman Sulaiman , Kourah Mohammed Abdelazim , Mahmoud Samir Fahmi
Published: June 2014

Frequency‐reconfigurable designs of a probe‐fed multi‐mode H‐shaped microstrip antenna are presented. The reconfigurability is achieved by symmetrically loading the antenna with varactor diodes. The design approach for the proposed antennas is to control the propagating modes by matching a specific mode or two modes while mismatching the other modes in order to achieve single‐band or dual‐band operation, respectively. The key to such approach is the careful selection of the varactors’ positions and type. Two single‐band designs are proposed where each tunes a different resonant mode of the H‐shaped microstrip antenna. The two designs are only different in the type of the used varactors. One of these designs achieves 41% tuning range (2.22–3.37 GHz), while the other achieves 16% (3.77–4.45 GHz). A dual‐band design is proposed where one of the bands is fixed at 2.728 GHz while the other is tunable. The dual‐band antenna achieves a 32% tuning range (1.89–2.6 GHz) for the tunable mode. All of the designs are implemented on 80 × 80 × 1.57 mm3 substrate with εr = 2.2. Good agreement between the measured and simulated results of these designs is observed.
Determining spectral response of a photovoltaic device using polychromatic filters
Authors: Sara Ira Devi , Betts Thomas R. , Gottschalg Ralph
Published: June 2014

This study introduces a new method for determining the spectral response of a photovoltaic (PV) device. Instead of illuminating the PV device under test with monochromatic beams at different wavelengths, the device is irradiated with different broadband spectra. Variations in the spectra are made by employing different types of polychromatic filters. The advantage of using these types of filters is the increase in the light intensity incident on the measurement plane, compared with narrowband filtered light. As a consequence, the spectral response measurement setup becomes very simple, comprising only a light source, a set of polychromatic filters, spectroradiometer and source‐meter unit. The spectral response is determined by fitting the short‐circuit currents measured under different spectra to a chosen spectral response model. The proposed method is verified by comparing the results to spectral response curves measured with a traditional monochromatic method, which show excellent agreement. From this analysis, it can be concluded that the proposed method is feasible as a new technique for determining the spectral response of a PV device.
Improved ion implant fluence uniformity in hydrogen enhanced glow discharge plasma immersion ion implantation into silicon
Authors: Luo J. , Li L. H. , Liu H. T. , Yu K. M. , Xu Y. , Zuo X. J. , Zhu P. Z. , Ma Y. F. , Fu Ricky K. Y. , Chu Paul K.
Published: June 2014

Enhanced glow discharge plasma immersion ion implantation does not require an external plasma source but ion focusing affects the lateral ion fluence uniformity, thereby hampering its use in high-fluence hydrogen ion implantation for thin film transfer and fabrication of silicon-on-insulator. Insertion of a metal ring between the sample stage and glass chamber improves the ion uniformity and reduces the ion fluence non-uniformity as the cathode voltage is raised. Two-dimensional multiple-grid particle-in-cell simulation confirms that the variation of electric field inside the chamber leads to mitigation of the ion focusing phenomenon and the results are corroborated experimentally by hydrogen forward scattering.
Frequency and temperature dependence of actuating performance of Bi1/2Na1/2TiO3-BaTiO3 based relaxor/ferroelectric composites
Authors: Groh Claudia , Jo Wook , Rödel Jürgen
Published: June 2014

Recently, composites of relaxors (matrix) and either ferroelectric or nonergodic relaxor (seed) were proposed as a solution to resolving one of the main drawbacks of incipient piezoceramics, namely the requirement for high driving electric fields. In this study, we investigate the temperature and frequency dependence of the actuating performance of Bi1/2Na1/2TiO3-BaTiO3-based composites. Apart from the reduction of driving field, the composite architecture offers an extra degree of freedom for tailoring the temperature stability for different operational conditions for actuators. High strain values appear to be sensitive especially to driving frequency. This is originated by the time-dependent process of the coalescence of polar nanoregions. In effect, proximity of driving field and poling field leads to high strain sensitivity. Hence, the driving electric field needs to be adjusted in order to meet the desired frequency specifications for given applications.
2D IR spectroscopy reveals the role of water in the binding of channel-blocking drugs to the influenza M2 channel
Authors: Ghosh Ayanjeet , Wang Jun , Moroz Yurii S. , Korendovych Ivan V. , Zanni Martin , DeGrado William F. , Gai Feng , Hochstrasser Robin M.
Published: June 2014

Water is an integral part of the homotetrameric M2 proton channel of the influenza A virus, which not only assists proton conduction but could also play an important role in stabilizing channel-blocking drugs. Herein, we employ two dimensional infrared (2D IR) spectroscopy and site-specific IR probes, i.e., the amide I bands arising from isotopically labeled Ala30 and Gly34 residues, to probe how binding of either rimantadine or 7,7-spiran amine affects the water dynamics inside the M2 channel. Our results show, at neutral pH where the channel is non-conducting, that drug binding leads to a significant increase in the mobility of the channel water. A similar trend is also observed at pH 5.0 although the difference becomes smaller. Taken together, these results indicate that the channel water facilitates drug binding by increasing its entropy. Furthermore, the 2D IR spectral signatures obtained for both probes under different conditions collectively support a binding mechanism whereby amantadine-like drugs dock in the channel with their ammonium moiety pointing toward the histidine residues and interacting with a nearby water cluster, as predicted by molecular dynamics simulations. We believe these findings have important implications for designing new anti-influenza drugs.
Molecular dynamics simulations of the amino acid-ZnO (10-10) interface: A comparison between density functional theory and density functional tight binding results
Authors: große Holthaus Svea , Köppen Susan , Frauenheim Thomas , Ciacchi Lucio Colombi
Published: June 2014

We investigate the adsorption behavior of four different amino acids (glutamine, glutamate, serine, cysteine) on the zinc oxide \documentclass[12pt]{minimal}\begin{document}$(10\bar{1}0)$\end{document}(101¯0) surface, comparing the geometry and energy associated with a number of different adsorption configurations. In doing this, we highlight the benefits and limits of using density-functional tight-binding (DFTB) with respect to standard density functional theory (DFT). The DFTB method is found to reliably reproduce the DFT adsorption geometries. Analysis of the adsorption configurations emphasizes the fundamental role of the first hydration layer in mediating the interactions between the amino acids and the surface. Direct surface-molecule bonds are found to form predominantly via the carboxylate groups of the studied amino acids. No surface-mediated chemical reactions are observed, with the notable exception of a proton transfer from the thiol group of cysteine to a hydroxyl group of the surface hydration layer. The adsorption energies are found to be dominated both by the formation of direct or indirect surface-molecule hydrogen bonds, but also by the rearrangement of the hydrogen-bond network in surface proximity in a non-intuitive way. Energetic comparisons between DFTB and DFT are made difficult on one side by the long time necessary to achieve convergence of potential energy values in MD simulations and on the other side by the necessity of including higher-order corrections to DFTB to obtain a good description of the hydrogen bond energetics. Overall, our results suggest that DFTB is a good reference method to set the correct chemical states and the initial geometries of hybrid biomolecule/ZnO systems to be simulated with non-reactive force fields.
Striking role of non-bridging oxygen on glass transition temperature of calcium aluminosilicate glass-formers
Authors: Bouhadja M. , Jakse N. , Pasturel A.
Published: June 2014

Molecular dynamics simulations are used to study the structural and dynamic properties of calcium aluminosilicate, (CaO-Al2O3)1−x(SiO2)x, glass formers along three joins, namely, R = 1, 1.57, and 3, in which the silica content x can vary from 0 to 1. For all compositions, we determined the glass-transition temperature, the abundances of the non-bridging oxygen, triclusters, and AlO5 structural units, as well as the fragility from the temperature evolution of the α-relaxation times. We clearly evidence the role played by the non-bridging oxygen linked either to Al atoms or Si atoms in the evolution of the glass-transition temperature as well as of the fragility as a function of silica content along the three joins.
A quasi-optical vector near-field measurement system at terahertz band
Authors: Lou Zheng , Hu Jie , Zhou Kang-Min , Miao Wei , Shi Sheng-Cai
Published: June 2014

This paper describes a vector near-field measurement system at terahertz band based on a high sensitivity superconducting receiver equipped with a quasi-optical probe for high resolution near-field sensing. A novel single-receiver rather than commonly used dual-receiver configuration is adopted for vector measurement. Performances of the measurement system including stability and dynamic range are studied. Vector near-field measurement of a diagonal feedhorn at 850 GHz is presented and shows good agreement with simulation and direct far-field measurement.
Coded aperture imaging for fluorescent x-rays
Authors: Haboub A. , MacDowell A. A. , Marchesini S. , Parkinson D. Y.
Published: June 2014

We employ a coded aperture pattern in front of a pixilated charge couple device detector to image fluorescent x-rays (6–25 KeV) from samples irradiated with synchrotron radiation. Coded apertures encode the angular direction of x-rays, and given a known source plane, allow for a large numerical aperture x-ray imaging system. The algorithm to develop and fabricate the free standing No-Two-Holes-Touching aperture pattern was developed. The algorithms to reconstruct the x-ray image from the recorded encoded pattern were developed by means of a ray tracing technique and confirmed by experiments on standard samples.
Charge transfer from an adsorbed ruthenium-based photosensitizer through an ultra-thin aluminium oxide layer and into a metallic substrate
Authors: Gibson Andrew J. , Temperton Robert H. , Handrup Karsten , Weston Matthew , Mayor Louise C. , O’Shea James N.
Published: June 2014

The interaction of the dye molecule N3 (cis-bis(isothiocyanato)bis(2,2-bipyridyl-4,4′-dicarbo-xylato)-ruthenium(II)) with the ultra-thin oxide layer on a AlNi(110) substrate, has been studied using synchrotron radiation based photoelectron spectroscopy, resonant photoemission spectroscopy, and near edge X-ray absorption fine structure spectroscopy. Calibrated X-ray absorption and valence band spectra of the monolayer and multilayer coverages reveal that charge transfer is possible from the molecule to the AlNi(110) substrate via tunnelling through the ultra-thin oxide layer and into the conduction band edge of the substrate. This charge transfer mechanism is possible from the LUMO+2 and 3 in the excited state but not from the LUMO, therefore enabling core-hole clock analysis, which gives an upper limit of 6.0 ± 2.5 fs for the transfer time. This indicates that ultra-thin oxide layers are a viable material for use in dye-sensitized solar cells, which may lead to reduced recombination effects and improved efficiencies of future devices.
Properties of subentropy
Authors: Datta Nilanjana , Dorlas Tony , Jozsa Richard , Benatti Fabio
Published: June 2014

Subentropy is an entropy-like quantity that arises in quantum information theory; for example, it provides a tight lower bound on the accessible information for pure state ensembles, dual to the von Neumann entropy upper bound in Holevo's theorem. Here we establish a series of properties of subentropy, paralleling the well-developed analogous theory for von Neumann entropy. Further, we show that subentropy is a lower bound for min-entropy. We introduce a notion of conditional subentropy and show that it can be used to provide an upper bound for the guessing probability of any classical-quantum state of two qubits; we conjecture that the bound applies also in higher dimensions. Finally, we give an operational interpretation of subentropy within classical information theory.
Phase-sensitive magnetoresistance oscillations induced by commensurate bichromatic irradiations in a two-dimensional electron system
Authors: Lei X. L. , Liu S. Y.
Published: June 2014

We analyze a phase-sensitive contribution to the oscillating magnetoresistance induced by the combined driving of two microwave fields having commensurate frequencies ω1 and ω2 (m1ω1 + m2ω2 = 0 for at least a set of nonzero integers m1 and m2), based on the balance-equation approach to magnetotransport for high-density two-dimensional electron systems. This commensurate oscillating photoresistance not only depends on the frequencies and polarizations of both microwaves, but varies drastically when changing the relative phases of two incident radiation fields. It shows up most significantly in the case of ω2/ω1 = 3 and may lead to a phase-controllable change of more than a factor of two in the total magnetoresistivity in the vicinity of ω1/ωc = 1.5 and 2.5 (ωc is the cyclotron frequency), when both radiation fields are linearly x-direction polarized.