bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional characterization ofSjB10, an intracellular serpin fromSchistosoma japonicum
Authors: MOLEHIN ADEBAYO J. , GOBERT GEOFFREY N. , DRIGUEZ PATRICK , MCMANUS DONALD P.
Published: August 2014

Serine protease inhibitors (serpin) play essential roles in many organisms. Mammalian serpins regulate the blood coagulation, fibrinolysis, inflammation and complement activation pathways. In parasitic helminths, serpins are less well characterized, but may also be involved in evasion of the host immune response. In this study, aSchistosoma japonicumserpin (SjB10), containing a 1212 bp open reading frame (ORF), was cloned, expressed and functionally characterized. Sequence analysis, comparative modelling and structural-based alignment revealed thatSjB10contains the essential structural motifs and consensus secondary structures of inhibitory serpins. Transcriptional profiling demonstrated thatSjB10is expressed in adult males, schistosomula and eggs but particularly in the cercariae, suggesting a possible role in cercarial penetration of mammalian host skin. RecombinantSjB10(rSjB10) inhibited pancreatic elastase (PE) in a dose-dependent manner.rSjB10was recognized strongly by experimentally infected rat sera indicating that nativeSjB10is released into host tissue and induces an immune response. By immunochemistry,SjB10localized in theS. japonicumadult foregut and extra-embryonic layer of the egg. This study provides a comprehensive demonstration of sequence and structural-based analysis of a functionalS. japonicumserpin. Furthermore, our findings suggest thatSjB10may be associated with important functional roles inS. japonicumparticularly in host-parasite interactions.
Competing conceptions of God: the personal God versus the God beyond being
Authors: STENMARK MIKAEL
Published: August 2014

Among philosophers and theologians today, one of the most important dividing lines is the one separating those who advocate a personal conception of God (personal theism) from those who embrace the idea of a God beyond or without being (alterity theism). There is not much dialogue between these groups of scholars; rather the two groups ignore each other, and each party typically believes that there is a fairly straightforward knockdown argument against the other. In this article I explore these two standard objections – the idolatry objection and the no-sense objection – and show why they both fail to be convincing. This failure to convince is a good thing, because it opens up the possibility that both personal theism and alterity theism are legitimate research programmes, each worthy of being further developed in philosophical theology.
Introduction
Authors: Crago Martha , Dussias Giuli
Published: August 2014

This Special Issue of Applied Psycholinguistics raises not only several issues about the human brain's behavior as manifest in the processing of language, but it is also intended to elicit scientific dialogue.
Moving toward a neuroplasticity view of bilingualism, executive control, and aging
Authors: BAUM SHARI , TITONE DEBRA
Published: August 2014

Normal aging is an inevitable race between increasing knowledge and decreasing cognitive capacity. Crucial to understanding and promoting successful aging is determining which of these factors dominates for particular neurocognitive functions. Here, we focus on the human capacity for language, for which healthy older adults are simultaneously advantaged and disadvantaged. In recent years, a more hopeful view of cognitive aging has emerged from work suggesting that age-related declines in executive control functions are buffered by life-long bilingualism. In this paper, we selectively review what is currently known and unknown about bilingualism, executive control, and aging. Our ultimate goal is to advance the views that these issues should be reframed as a specific instance of neuroplasticity more generally and, in particular, that researchers should embrace the individual variability among bilinguals by adopting experimental and statistical approaches that respect the complexity of the questions addressed. In what follows, we set out the theoretical assumptions and empirical support of the bilingual advantages perspective, review what we know about language, cognitive control, and aging generally, and then highlight several of the relatively few studies that have investigated bilingual language processing in older adults, either on their own or in comparison with monolingual older adults. We conclude with several recommendations for how the field ought to proceed to achieve a more multifactorial view of bilingualism that emphasizes the notion of neuroplasticity over that of simple bilingual versus monolingual group comparisons.
Neuroplasticity of the bilingual brain: Cognitive control and reserve
Authors: Abutalebi Jubin , Rietbergen Marpessa J.
Published: August 2014

The impacts of bilingualism upon the human brain, specifically in terms of the neuroplastic and neurofunctional changes upon general cognitive functions and on cognitive decline, are currently attracting much attention not only from the neuroscience and psycholinguistic communities but also from the general public. Researchers are especially focused on the putative protective effects of bilingualism upon cognitive decline.
Individual variability and neuroplastic changes
Authors: Green David W.
Published: August 2014

An important proposal in the insightful Keynote Article by Baum and Titone is that the field of bilingualism research needs to attend more closely to intersubject variability in order to understand the nature of neuroplastic changes in the brains of bilingual speakers as they age. I agree. Understanding such variability and its drivers (such as the contexts of language use that Baum and Titone nicely comment on in the Montreal milieu) will help us develop theoretical accounts of the cognitive control processes recruited in bilingual speakers and establish how adaptive changes to these processes mediate the effects of normal aging; yield protective effects against neurodegenerative disease, such as Alzheimer disease; and modulate language recovery poststroke in bilingual speakers. In this commentary I explore some aspects of this variability and commend, in line with the views expressed in the Keynote Article, the value of relating behavioral indices to whole brain structural magnetic resonance imaging for enriching our understanding of experience-dependent changes. Allied to tractography studies, such research can help us develop a rich picture of the major drivers of neuroplastic changes.
SPECIFICATION TESTS FOR LATTICE PROCESSES
Authors: Hidalgo Javier , Seo Myung Hwan
Published: August 2014

We consider an omnibus test for the correct specification of the dynamics of a sequence$\left\{ {x\left( t \right)} \right\}_{t \in Z^d } $in a lattice. As it happens with causal models andd= 1, its asymptotic distribution is not pivotal and depends on the estimator of the unknown parameters of the model under the null hypothesis. One first main goal of the paper is to provide a transformation to obtain an asymptotic distribution that is free of nuisance parameters. Secondly, we propose a bootstrap analog of the transformation and show its validity. Thirdly, we discuss the results when$\left\{ {x\left( t \right)} \right\}_{t \in Z^d } $are the errors of a parametric regression model. As a by product, we also discuss the asymptotic normality of the least squares estimator of the parameters of the regression model under very mild conditions. Finally, we present a small Monte Carlo experiment to shed some light on the finite sample behavior of our test.
L’ancien français n’est déjà plus une langue à sujet nul–nouveau témoignage des textes légaux
Authors: BALON LAURENT , LARRIVÉE PIERRE
Published: August 2014

Cet article a pour objet la réévaluation de la chronologie de la perte du statut de langue à sujet optionnel du français. Traditionnellement, on suppose que ce processus de changement syntaxique a lieu entre le passage de l’ancien au moyen français: le sujet nul aurait commencé à perdre sa prépondérance au XIIIesiècle pour devenir minoritaire dans la deuxième moitié du XVesiècle. Cette supposition est cependant basée sur le témoignage de textes littéraires. Ayant une visée stylistique, les textes littéraires sont connus pour leur conservatisme. Ce conservatisme pose la question de la fiabilité de leur témoignage pour la chronologie et le processus du changement linguistique effectif (Ingham sous presse). Une meilleure compréhension du changement linguistique pourrait être développée par l'étude des textes légaux, moins assujettis que les textes littéraires à des préoccupations d’ordre stylistique. Cette étude suggère qu’au début du XIIIesiècle, l’ancien français avait déjà perdu la possibilité d’omettre le sujet. En outre, les corrélations avec l’impersonnel et le type de proposition y diffèrent de celles qu’on retrouve dans les textes littéraires, invitant à une réévaluation des causes de ce changement.
The comparative effects of small geographic range and population decline on the adult sex ratio of threatened bird species
Authors: VENABLES J. C. , BROOKE M. de L.
Published: August 2014

Although the factors associated with adult sex ratio (ASR) skew in threatened species are rarely identified, ASRs of threatened species appear to be more male-skewed with increasing severity of threat. In this study we investigate whether the ASRs of species classified as threatened because of decline are significantly different from those threatened because of small range. Despite previous studies suggesting an association between male-skewed ASRs and population decline, our results show that ASRs may be more male-skewed in species classified as threatened because of small range. Although selection would be expected to purge dispersal genotypes from isolated populations, our finding could result from an imbalance between immigration and emigration rates of species with small ranges. Future research should examine rates of emigration and immigration in species with small global ranges.
In Memory of Philippe Flajolet
Authors: Sedgewick Robert
Published: August 2014

In 2011, shortly after his untimely passing, several colleagues and I wrote an obituary for Philippe Flajolet [5] that includes the following:

He was the leading figure in the development of the international ‘AofA’ community that is devoted to research on probabilistic, combinatorial, and asymptotic methods in the analysis of algorithms. The colleagues and students who are devoted to carrying on his work form the core of his primary legacy.

This special issue is testimony to that legacy. Many of the dozens of authors who are represented here worked closely with Philippe; many others have been inspired by his work. All are devoted to carrying it on.
COMPETITION AS AN ENGINE OF ECONOMIC GROWTH WITH PRODUCER HETEROGENEITY
Authors: Jensen Christian
Published: August 2014

When producers are heterogeneous, the degree of competition between them affects aggregate output not only via markups and deadweight losses, but also through aggregate productivity due to specialization. As competition tightens, high-productivity producers gain market share at the cost of low-productivity ones, generating economic growth through increased aggregate productivity and capital accumulation, in line with what is observed empirically. Consequently, competition is not limited to reducing deadweight losses, and can play a greater role in economic growth and development than traditionally assumed. Economic growth spurs profits, which leads to entry and increased competition that generates growth, so competition provides a channel through which the economy generates growth internally. When strong enough, this channel can make the returns to scale in the inputs that the economy accumulates endogenously go from being decreasing to nondecreasing at the aggregate level, thus enabling endogenous growth. In fact, these returns to scale are determined endogenously in our model, and vary with the scale of production, the degree of producer heterogeneity, and the barriers to entry.
INTERIORITY, THE ‘DEEP EARTH’ AND THE SPATIAL SYMBOLISM OF DARIUS' APPARITION IN THEPERSIANSOF AESCHYLUS
Authors: Bakola Emmanuela
Published: August 2014

This article demonstrates that the spatial category of depth is crucial for understanding Aeschylus'Persians. Underground spaces are often symbolically represented in Greek drama not only on a vertical axis but also by the interior of the stage-building (skene). By investigating the connections between ‘interiority’ and ‘depth’, this article argues that the most economical and effective reconstruction of Darius' apparition is to suppose that he emerged from the interior of theskene, whose existence at this date is often disputed. The article furthermore analyses the multifaceted concept of the earth in thePersians, to suggest new ways in which underground, ground and interior spaces can be connected holistically to other spatial and natural imagery.
Spine-like Nanostructured Carbon Interconnected by Graphene for High-performance Supercapacitors
Authors: Park Sang-Hoon , Yoon Seung-Beom , Kim Hyun-Kyung , Han Joong Tark , Park Hae-Woong , Han Joah , Yun Seok-Min , Jeong Han Gi , Roh Kwang Chul , Kim Kwang-Bum
Published: August 2014

Recent studies on supercapacitors have focused on the development of hierarchical nanostructured carbons by combining two-dimensional graphene and other conductive sp2 carbons, which differ in dimensionality, to improve their electrochemical performance. Herein, we report a strategy for synthesizing a hierarchical graphene-based carbon material, which we shall refer to as spine-like nanostructured carbon, from a one-dimensional graphitic carbon nanofiber by controlling the local graphene/graphitic structure via an expanding process and a co-solvent exfoliation method. Spine-like nanostructured carbon has a unique hierarchical structure of partially exfoliated graphitic blocks interconnected by thin graphene sheets in the same manner as in the case of ligaments. Owing to the exposed graphene layers and interconnected sp2 carbon structure, this hierarchical nanostructured carbon possesses a large, electrochemically accessible surface area with high electrical conductivity and exhibits high electrochemical performance.
Biomimetic Materials and Surfaces in Detection
Authors: Boehm Ryan D. , Narayan Roger J.
Published: August 2014

Biomimetic surfaces and materials may be utilized in biosensing applications, harnessing material properties that mimic the natural environment of a biomolecule in order to maintain its functionality, artificially create a complex that takes on the form of a biomolecular structure, or modify an environment to promote cellular affinity. Throughout the scientific literature, there are numerous mechanisms by which this concept may be accomplished. Synthetic lipid membranes, meant to mimic a cellular membrane, have been deposited onto sensor platforms for analyte detection with immobilized functional biomolecules. Natural biomolecules may also be immobilized on transducers, with care taken to protect their functionality (e.g., through polymer linkages), allowing them to operate as sensing units. Synthetic molecular constructs have been developed to mimic the activity of biomolecules. Molecularly imprinted polymers have been created, operating as artificial bioaffinity recognition sites for target molecules. Furthermore, whole cells may be immobilized onto sensing surfaces, acting as sensing units or mimics of larger tissue systems. In this chapter, the relevant literature examples are discussed, highlighting the means by which these biomimetic sensing approaches are accomplished.
Smart Indicator Technologies for Chemical and Biochemical Detection
Authors: Reddy Subrayal M.
Published: August 2014

Chemists have become familiar with a range of chemical indicator reactions which can be used as qualitative, presumptive and/or semi-quantitative tests for the presence of organic or inorganic compounds of interest. For example, the silver mirror test for aldehydes, based on the reduction of ammoniacal silver nitrate to metallic silver, allows discrimination between aldehydes and ketones; the precipitation tests with silver nitrate for the presence of a halide; and universal indicator and litmus papers for pH and colour-changing indicators to mark the end-point of a titration are all examples of quick visual tests which have been used by chemists. The convenience of such visual indicators has also been adopted in the development of a range of bio/chemical tests for the presence of, for example, volatile organic compounds, proteins, bacteria and also metabolites, as well as for presumptive tests of drugs of abuse. This chapter reviews a selection of the chemistries developed to make simple visual indicators for chemical and biological applications. These indicators have far-reaching implications to the layperson, for example in the development of simple tests informative of medical (personal health) and food (the integrity of food packaging, fruit ripeness and food quality) monitoring.
A real-time immuno-PCR assay for the detection of tetrabromobisphenol A
Authors: Bu Dan , Zhuang Huisheng , Yang Guangxin , Ping Xianyin
Published: August 2014

In this study, a reliable and ultra-sensitive indirect competitive real-time immuno-PCR (rt-iPCR) was established for the determination of tetrabromobisphenol A (TBBPA).
Porosity control in mesoporous polymers using CO2-swollen block copolymer micelles as templates and their use as catalyst supports
Authors: Peng Li , Zhang Jianling , Yang Shuliang , Han Buxing , Sang Xinxin , Liu Chengcheng , Yang Guanying
Published: August 2014

Mesoporous polymers with tunable large mesopores (14–22 nm) were synthesized through a CO2-swollen micelle templating route.
Efficient halogen photoelimination from dibromo, dichloro and difluoro tellurophenes
Authors: Carrera Elisa I. , Seferos Dwight S.
Published: August 2014

Visible light induces photoreductive elimination of bromine, chlorine, and for the first time, fluorine from the tellurium center of 2,5-diphenyltellurophene.
The applicability of proton transfer reaction-mass spectrometry (PTR-MS) for determination of isocyanic acid (ICA) in work room atmospheres
Authors: Jankowski Mikolaj Jan , Olsen Raymond , Nielsen Claus Jørgen , Thomassen Yngvar , Molander Paal
Published: August 2014

This study presents a real-time method to quantitatively determine isocyanic acid (ICA) in workroom air using a proton transfer reaction-mass spectrometer (PTR-MS).
A new approach combining LC-MS and multivariate statistical analysis for revealing changes in histone modification levels
Authors: Bilgraer Raphaël , Gillet Sylvie , Gil Sophie , Evain-Brion Danièle , Laprévote Olivier
Published: August 2014

We have developed a new global histonomic approach for deciphering histone code disruption in human cells after xenobiotic exposure.
Flexibility versus rigidity: what determines the stability of zeolite frameworks? A case study
Authors: Verheyen E. , Joos L. , Martineau C. , Dawson C. J. , Weidenthaler C. , Schmidt W. , Yuan R. , Breynaert E. , Van Speybroeck V. , Waroquier M. , Taulelle F. , Treacy M. M. J. , Martens J. A. , Kirschhock C. E. A.
Published: August 2014

The unique case ofCOK-14existing in a relaxed interrupted and rigid connected state provides insight into the stability and feasibility of zeolite frameworks.
Exploring functional cyclophellitol analogues as human retaining beta-glucosidase inhibitors
Authors: Li Kah-Yee , Jiang Jianbing , Witte Martin D. , Kallemeijn Wouter W. , Donker-Koopman Wilma E. , Boot Rolf G. , Aerts Johannes M. F. G. , Codée Jeroen D. C. , van der Marel Gijsbert A. , Overkleeft Herman S.
Published: August 2014

Of six cyclophellitol analogues, the N-pentylaziridine is the most effective retaining human beta-glucosidase inhibitor considering potency and compound stability.
An insight into the effective advanced oxidation process for treatment of simulated textile dye waste water
Authors: Guin Jhimli Paul , Naik D. B. , Bhardwaj Y. K. , Varshney Lalit
Published: August 2014

The comparison in the extent of % mineralization of Simulated Textile Dye Waste Water (STDWW) in three Advanced Oxidation Processes.
Anion selective chromogenic and fluorogenic chemosensor and its application in breast cancer live cell imaging
Authors: Sharma Darshna , Moirangthem Anuradha , Sahoo Suban K. , Basu Anupam , Roy Sutapa M. , Pati Ranjan K. , Kumar SK Ashok , Nandre Jitendra P. , Patil Umesh D.
Published: August 2014

A novel anion selective chromogenic and fluorogenic chemosensor (L) bearing catechol and phenol groups was developed. The sensorLwas tested for live breast cancer cell imaging and can be applied to the breast tumour diagnosis.
Size dependence of the lattice parameters of carbon supported platinum nanoparticles: X-ray diffraction analysis and theoretical considerations
Authors: Leontyev I. N. , Kuriganova A. B. , Leontyev N. G. , Hennet L. , Rakhmatullin A. , Smirnova N. V. , Dmitriev V.
Published: August 2014

The size effect of Pt/C nanoparticles with diameters ranging from 2 to 28 nm have been studied using X-ray diffraction.
Facile ion-exchange synthesis of urchin-shaped CdS/Bi2S3 heterostructures with enhanced photostability and visible light photocatalytic activity
Authors: Yan Yunhui , Zhou Zhaoxian , Li Wuqi , Zhu Yanjie , Cheng Yun , Zhao Fengying , Zhou Jianguo
Published: August 2014

Core/shell CdS/Bi2S3 heterostructures have been synthesized through in situ cation-exchange method. These heterostructures exhibit enhanced photostability and visible light photocatalytic activity.
pH-sensitive amphiphilic copolymer brush Chol-g-P(HEMA-co-DEAEMA)-b-PPEGMA: synthesis and self-assembled micelles for controlled anti-cancer drug release
Authors: Zhang Can Yang , Wu Wen Sheng , Yao Na , Zhao Bin , Zhang Li Juan
Published: August 2014

A novel pH-sensitive amphiphilic copolymer Chol-g-P(HEMA-co-DEAEMA)-b-PPEGMA and its micelles were developed as a promising anti-cancer drug carrier.
Studies on mechanical, thermal and dynamic mechanical properties of functionalized nanoalumina reinforced sulphone ether linked tetraglycidyl epoxy nanocomposites
Authors: Duraibabu D. , Alagar M. , Kumar S. Ananda
Published: August 2014

The objective of the present work is to synthesize 1,4′-bis (4-amine-phenoxy) sulphone benzene epoxy resin (TGBAPSB) via 1,4′-bis (4-amine-phenoxy) sulphone benzene (BAPSB) and epichlorohydrin in order to obtain tetra functional epoxy with improved properties.
Hybrid magnetic scaffolds of gelatin–siloxane incorporated with magnetite nanoparticles effective for bone tissue engineering
Authors: Dashnyam Khandmaa , Perez Roman A. , Singh Rajendra K. , Lee Eun-Jung , Kim Hae-Won
Published: August 2014

Hybrid magnetic scaffolds of silica–gelatin-MNs newly developed to have excellent physicochemical, mechanical and biological properties that are effective for bone tissue engineering.
First analysis of the Herzberg (C1Σ+→ A1Π) band system in the less-abundant13C17O isotopologue
Authors: Hakalla Rafał
Published: August 2014

This work presents high-resolution emission spectra measurements of the Herzberg band system, which has not been observed and analysed in the13C17O isotopologue so far.
Colloidal structures of asymmetric dimers via orientation-dependent interactions
Authors: Ma Fuduo , Wang Sijia , Zhao Hui , Wu David T. , Wu Ning
Published: August 2014

The orientation-dependent interactions between asymmetric dimers induce a series of colloidal structures that closely resemble one- and two-dimensional antiferromagnetic lattices under AC electric fields.
Enhancing the carbon yield of cellulose based carbon fibres with ionic liquid impregnates
Authors: Byrne Nolene , Chen Jingyu , Fox Bronwyn
Published: August 2014

We report the use of ionic liquids as novel impregnates to enhance the carbon yield of cellulose based carbon fibres. It was found that ILs which contain a phosphate anion improved the carbon yield the most, with a 50% increase in carbon yield reported. Additionally the use of the ionic liquid impregnate lowered the depolymerization temperature by 70 °C, which reflects significant potential saving in the energy costs of carbonization.
Biodegradable electroactive polymers for electrochemically-triggered drug delivery
Authors: Hardy John G. , Mouser David J. , Arroyo-Currás Netzahualcóyotl , Geissler Sydney , Chow Jacqueline K. , Nguy Lindsey , Kim Jong M. , Schmidt Christine E.
Published: August 2014

We report biodegradable electroactive polymer (EAP)-based materials and their application as drug delivery devices.
Thermally activated reversible shape switch of polymer particles
Authors: Gong Tao , Zhao Kun , Wang Wenxi , Chen Hongmei , Wang Lin , Zhou Shaobing
Published: August 2014

Shape-switchable micrometer-sized particles have the ability to reversibly switch their shapes between 43 and 0 °C via a two-way shape memory effect.
Wideband tri‐port MIMO antenna with compact size and directional radiation pattern
Authors: Wang Han , Liu Longsheng , Zhang Zhijun , Feng Zhenghe
Published: August 2014

A wideband tri‐port multiple‐input‐multiple‐output (MIMO) antenna designed for worldwide interoperability for microwave access (WiMAX) and wireless local area network (WLAN) applications is presented. The proposed antenna is composed of three printed dipoles with an integrated balun, the size of which is only 0.08λ2. By introducing ground stubs between adjacent elements, impedance matching is improved and mutual coupling is reduced. A bandwidth of 51.6% (2.30–3.90 GHz) with S11 <−10 dB and S12, S13 <−10 dB is achieved, which can cover the whole three WiMAX bands and the 2.4 GHz WLAN band. Moreover, directional radiation patterns are achieved in these bands, and the average gain reaches 3.5 dB with up to 21.4 dB front‐to‐back ratio. The envelope correlation coefficient is below 0.038, which can provide good pattern diversity for a MIMO system.
IUPAC-NIST Solubility Data Series. 103. Oxygen and Ozone in Water, Aqueous Solutions, and Organic Liquids (Supplement to Solubility Data Series Volume 7)
Authors: Miyamoto Hiroshi , Yampolski Yuri , Young Colin L.
Published: August 2014

This volume is an update of the Solubility Data Series Volume 7 published in 1981 on oxygen and ozone. For this volume, the literature was covered from 1981 to 2009 with some papers from 2010. Some earlier papers missed in the 1981 volume are included. Interest in the solubility of oxygen and of ozone continues to be high. The solubility of oxygen in water at low pressure seems well established, but more work is needed on the solubility of oxygen in water at high pressure and high temperature. There is now a wealth of salt-effect data on the solubility in aqueous salt solutions, but some glaring discrepancies still exist. Little has been done on salt effects at high pressure and high temperature. The solubility data of oxygen in hydrocarbons seem sparse. The solubility of oxygen in alcohols through C5 seems well established. Between the 1981 volume and this volume, there are solubility data in over 70 fluorocarbons and fluorocarbon compounds with O, H, S, and N. A new area is the solubility of oxygen in ionic liquids, which are becoming increasingly important as replacement solvents for volatile organic solvents. Information on the solubility of ozone in water, aqueous solutions and organic liquids has also been updated.
A coarse-grained method based on the analysis of short molecular dynamics trajectories for the simulation of non-Markovian dynamics of molecules adsorbed in microporous materials
Authors: Pintus Alberto M. , Gabrieli Andrea , Pazzona Federico G. , Demontis Pierfranco , Suffritti Giuseppe B.
Published: August 2014

We developed a coarse-grained model suitable for the study of adsorbed molecules in microporous materials. A partition of the space available to the motion of adsorbed molecules was carried out, which allows to formulate the dynamics in terms of jumps between discrete regions. The probabilities of observing given pairs of successive jumps were calculated from Molecular Dynamics (MD) simulations, performed on small systems, and used to drive the motion of molecules in a lattice-gas model. Dynamics is thus reformulated in terms of event-space dynamics and this allows to treat the system despite its inherent non markovity. Despite the assumptions enforced in the algorithm, results show that it can be applied to various spherical molecules adsorbed in the all-silica zeolite ITQ-29, establishing a suitable direct bridge between MD simulation results and coarse-grained models.
First measurements of highly ionized impurity emission distribution by grazing-incidence flat-field extreme ultraviolet spectrometer in HL-2A
Authors: Cui Zhengying , Dong Chunfeng , Zhou Hangyu , Morita Shigeru , Sun Ping , Fu Bingzhong , Lu Ping , Ding Xuantong , Yang Qingwei , Duan Xuru
Published: August 2014

A space-resolved grazing-incidence flat-field extreme ultraviolet (EUV) spectrometer has been developed in the HL-2A tokamak to measure vertical impurity emission profiles with simultaneous spectral, temporal, and spatial resolution. The spectrometer working in the wavelength range of 30–500 Å has been equipped with a gold-coated varied-line-spacing holographic grating with curvature of 5606 mm and a back illuminated charge-coupled device with size of 6.6 × 26.6 mm2 (255 × 1024 pixels). A lower half of the HL-2A plasma with averaged minor radius of 40 cm is observed when the spectrometer with horizontal dispersion is placed at a distance of 7.5 m away from the plasma center. An excellent spatial resolution of 12 mm is achieved when a space-resolved slit with vertical width of 0.5 mm is adopted. The radial profiles of intrinsic impurities in several ionization stages have been measured with high throughput and extremely low stray light.
Perturbational treatment of spin-orbit coupling for generally applicable high-level multi-reference methods
Authors: Mai Sebastian , Müller Thomas , Plasser Felix , Marquetand Philipp , Lischka Hans , González Leticia
Published: August 2014

An efficient perturbational treatment of spin-orbit coupling within the framework of high-level multi-reference techniques has been implemented in the most recent version of the Columbus quantum chemistry package, extending the existing fully variational two-component (2c) multi-reference configuration interaction singles and doubles (MRCISD) method. The proposed scheme follows related implementations of quasi-degenerate perturbation theory (QDPT) model space techniques. Our model space is built either from uncontracted, large-scale scalar relativistic MRCISD wavefunctions or based on the scalar-relativistic solutions of the linear-response-theory-based multi-configurational averaged quadratic coupled cluster method (LRT-MRAQCC). The latter approach allows for a consistent, approximatively size-consistent and size-extensive treatment of spin-orbit coupling. The approach is described in detail and compared to a number of related techniques. The inherent accuracy of the QDPT approach is validated by comparing cuts of the potential energy surfaces of acrolein and its S, Se, and Te analoga with the corresponding data obtained from matching fully variational spin-orbit MRCISD calculations. The conceptual availability of approximate analytic gradients with respect to geometrical displacements is an attractive feature of the 2c-QDPT-MRCISD and 2c-QDPT-LRT-MRAQCC methods for structure optimization and ab inito molecular dynamics simulations.
Efficient calculation of rate constants: Downhill versus uphill sampling
Authors: Klenin Konstantin V.
Published: August 2014

The classical transition state theory (TST), together with the notion of transmission coefficient, provides a useful tool for calculation of rate constants for rare events. However, in complex biomolecular reactions, such as protein folding, it is difficult to find a good reaction coordinate, so the transition state is ill-defined. In this case, other approaches are more popular, such as the transition interface sampling (TIS) and the forward flux sampling (FFS). Here, we show that the algorithms developed in the frames of TIS and FFS can be successfully applied, after a modification, for calculation of the transmission coefficient. The new procedure (which we call “downhill sampling”) is more efficient in comparison with the traditional TIS and FFS (“uphill sampling”) even if the reaction coordinate is bad. We also propose a new computational scheme that combines the advantages of TST, TIS, and FFS.
Guanidine and guanidinium cation in the excited state—theoretical investigation
Authors: Antol Ivana , Glasovac Zoran , Crespo-Otero Rachel , Barbatti Mario
Published: August 2014

Diverse ab initio and density-functional-theory methods were used to investigate geometries, energies, and electronic absorption spectra of guanidine and its protonated form, as well as their photo-deactivation processes. It was shown that the guanidine is a weakly absorbing species with the excitation spectrum consisting mostly of transitions to the Rydberg excited states and one valence n-π4 state. The lowest energy band has a maximum at ca. 6.9 eV (∼180 nm). The protonation of guanidine affects its excitation spectrum substantially. A major shift of the Rydberg states to higher energies is clearly visible and strongly absorbing transitions from the ground state to the π3-π4 and π2-π4 states appears at 7.8 eV (∼160 nm). Three low-lying conical intersections (two for guanidine and one for protonated guanidine) between the ground state and the first excited singlet state were located. They are accessible from the Franck–Condon region through amino N–H stretching and out-of-plane deformations in guanidine and protonated guanidine, respectively. The relaxation of the π3-3s Rydberg state via amino N–H bond stretching was hindered by a barrier. The nondissociated conical intersection in protonated guanidine mediates the radiationless deactivation of the compound after excitation into the π3-π4 state. This fact is detrimental for the photostability of guanidine, since its conjugate acid is stable in aqueous solution over a wide pH range and in protein environment, where guanidinium moiety in arginine is expected to be in a protonated form.
Change in entropy in thermal hysteresis of liquid-glass-liquid transition and consequences of violating the Clausius theorem
Authors: Tombari Elpidio , Johari G. P.
Published: August 2014

Change in the entropy, dS, with change in the temperature T, with or without phase transformation, is determined only if the thermal path is reversible. For an irreversible thermal path, dS > dqirrev/T, an expression known as inequality in the Clausius theorem. In the glass formation range, Cp and enthalpy show a time-dependent hysteresis between the cooling and heating paths and the two Cp paths cross each other. We provide new data on Cp of poly(styrene) and use the previous Cp data [E. Tombari, C. Ferrari, G. Salvetti, and G. P. Johari, Phys. Rev. B 78, 144203 (2008)], both data obtained from measurements performed on cooling from melt to glass and heating from glass to melt at unusually slow rates, and show that violation of the Clausius theorem in such cases has insignificant consequences for determining the entropy of glass. We also report Cp of the samples annealed for different times at different temperatures in which the enthalpy spontaneously decreased. These measurements also show that violation of the Clausius theorem is relatively inconsequential for interpreting the entropy of the glassy state.
Water permeability of nanoporous graphene at realistic pressures for reverse osmosis desalination
Authors: Cohen-Tanugi David , Grossman Jeffrey C.
Published: August 2014

Nanoporous graphene (NPG) shows tremendous promise as an ultra-permeable membrane for water desalination thanks to its atomic thickness and precise sieving properties. However, a significant gap exists in the literature between the ideal conditions assumed for NPG desalination and the physical environment inherent to reverse osmosis (RO) systems. In particular, the water permeability of NPG has been calculated previously based on very high pressures (1000–2000 bars). Does NPG maintain its ultrahigh water permeability under real-world RO pressures (<100 bars)? Here, we answer this question by drawing results from molecular dynamics simulations. Our results indicate that NPG maintains its ultrahigh permeability even at low pressures, allowing a permeate water flux of 6.0 l/h-bar per pore, or equivalently 1041 ± 20 l/m2-h-bar assuming a nanopore density of 1.7 × 1013 cm−2.
Non-oscillatory flux correlation functions for efficient nonadiabatic rate theory
Authors: Richardson Jeremy O. , Thoss Michael
Published: August 2014

There is currently much interest in the development of improved trajectory-based methods for the simulation of nonadiabatic processes in complex systems. An important goal for such methods is the accurate calculation of the rate constant over a wide range of electronic coupling strengths and it is often the nonadiabatic, weak-coupling limit, which being far from the Born-Oppenheimer regime, provides the greatest challenge to current methods. We show that in this limit there is an inherent sign problem impeding further development which originates from the use of the usual quantum flux correlation functions, which can be very oscillatory at short times. From linear response theory, we derive a modified flux correlation function for the calculation of nonadiabatic reaction rates, which still rigorously gives the correct result in the long-time limit regardless of electronic coupling strength, but unlike the usual formalism is not oscillatory in the weak-coupling regime. In particular, a trajectory simulation of the modified correlation function is naturally initialized in a region localized about the crossing of the potential energy surfaces. In the weak-coupling limit, a simple link can be found between the dynamics initialized from this transition-state region and an generalized quantum golden-rule transition-state theory, which is equivalent to Marcus theory in the classical harmonic limit. This new correlation function formalism thus provides a platform on which a wide variety of dynamical simulation methods can be built aiding the development of accurate nonadiabatic rate theories applicable to complex systems.
Communication: Nanoscale ion fluctuations in Nafion polymer electrolyte
Authors: Rumberger Brant , Bennett Mackenzie , Zhang Jingyun , Dura J. A. , Israeloff N. E.
Published: August 2014

Ion conduction mechanisms and the nanostructure of ion conduction networks remain poorly understood in polymer electrolytes which are used as proton-exchange-membranes (PEM) in fuel cell applications. Here we study nanoscale surface-potential fluctuations produced by Brownian ion dynamics in thin films of low-hydration Nafion™, the prototype PEM. Images and power spectra of the fluctuations are used to derive the local conductivity-relaxation spectrum, in order to compare with bulk behavior and hopping-conductivity models. Conductivity relaxation-times ranged from hours to milliseconds, depending on hydration and temperature, demonstrating that the observed fluctuations are produced by water-facilitated hydrogen-ion hopping within the ion-channel network. Due to the small number of ions probed, non-Gaussian statistics of the fluctuations can be used to constrain ion conduction parameters and mechanisms.
Improvement of the edge rotation diagnostic spectrum analysis via simulation
Authors: Luo J. , Zhuang G. , Cheng Z. F. , Zhang X. L. , Hou S. Y. , Cheng C.
Published: August 2014

The edge rotation diagnostic (ERD) system has been developed on the Joint Texas Experimental Tokamak to measure the edge toroidal rotation velocity by observing the shifted wavelength of carbon V (C V 227.09 nm). Since the measured spectrum is an integrated result along the viewing line from the plasma core to the edge, a method via simulation has been developed to analyze the ERD spectrum. With the necessary parameters such as C V radiation profile and the ion temperature profile, a local rotation profile at the normalized minor radius of 0.5-1 is obtained.
Role of cholesterol on the transfection barriers of cationic lipid/DNA complexes
Authors: Pozzi Daniela , Cardarelli Francesco , Salomone Fabrizio , Marchini Cristina , Amenitsch Heinz , Barbera Giorgia La , Caracciolo Giulio
Published: August 2014

Most lipid formulations need cholesterol for efficient transfection, but the precise motivation remains unclear. Here, we have investigated the effect of cholesterol on the transfection efficiency (TE) of cationic liposomes made of 1,2-dioleoyl-3-trimethylammonium-propane and dioleoylphosphocholine in Chinese hamster ovary cells. The transfection mechanisms of cholesterol-containing lipoplexes have been investigated by TE, synchrotron small angle X-ray scattering, and laser scanning confocal microscopy experiments. We prove that cholesterol-containing lipoplexes enter the cells using different endocytosis pathways. Formulations with high cholesterol content efficiently escape from endosomes and exhibit a lamellar-nonlamellar phase transition in mixture with biomembrane mimicking lipid formulations. This might explain both the DNA release ability and the high transfection efficiency. These studies highlight the enrichment in cholesterol as a decisive factor for transfection and will contribute to the rational design of lipid nanocarriers with superior TE.
Signatures of a conical intersection in photofragment distributions and absorption spectra: Photodissociation in the Hartley band of ozone
Authors: Picconi David , Grebenshchikov Sergy Yu.
Published: August 2014

Photodissociation of ozone in the near UV is studied quantum mechanically in two excited electronic states coupled at a conical intersection located outside the Franck-Condon zone. The calculations, performed using recent ab initio PESs, provide an accurate description of the photodissociation dynamics across the Hartley/Huggins absorption bands. The observed photofragment distributions are reproduced in the two electronic dissociation channels. The room temperature absorption spectrum, constructed as a Boltzmann average of many absorption spectra of rotationally excited parent ozone, agrees with experiment in terms of widths and intensities of diffuse structures. The exit channel conical intersection contributes to the coherent broadening of the absorption spectrum and directly affects the product vibrational and translational distributions. The photon energy dependences of these distributions are strikingly different for fragments created along the adiabatic and the diabatic paths through the intersection. They can be used to reverse engineer the most probable geometry of the non-adiabatic transition. The angular distributions, quantified in terms of the anisotropy parameter β, are substantially different in the two channels due to a strong anticorrelation between β and the rotational angular momentum of the fragment O2.
The role of the CN vibration in the activated dynamics of LiNC$\rightleftharpoons$⇌LiCN isomerization in an argon solvent at high temperatures
Authors: Garcia-Muller Pablo L. , Hernandez Rigoberto , Benito R. M. , Borondo F.
Published: August 2014

The isomerization between CN–Li and Li–CN in an argon bath provides a paradigmatic example of a reaction in a solvent with tunable coupling. In previous work, we found that the rates exhibited a turnover with the density of the argon bath in the limit that the CN bond was held fixed [P. L. Garcia-Muller, R. Hernandez, R. M. Benito, and F. Borondo, J. Chem. Phys. 137, 204301 (2012)]. Here, we report the effect of the CN bond vibration on the dynamics and the persistence of the turnover. As hypothesized earlier, the CN bond is indeed weakly coupled with the reaction path despite the presence of the argon cage.
Relating polarizability to volume, ionization energy, electronegativity, hardness, moments of momentum, and other molecular properties
Authors: Blair Shamus A. , Thakkar Ajit J.
Published: August 2014

Semiquantitative relationships between the mean static dipole polarizability and other molecular properties such as the volume, ionization energy, electronegativity, hardness, and moments of momentum are explored. The relationships are tested using density functional theory computations on the 1641 neutral, ground-state, organic molecules in the TABS database. The best polarizability approximations have median errors under 5%.
Thermal conductivity of compound semiconductors: Interplay of mass density and acoustic-optical phonon frequency gap
Authors: Jain Ankit , McGaughey Alan J. H.
Published: August 2014

The thermal conductivities of model compound semiconductors, where the two species differ only in mass, are predicted using lattice dynamics calculations and the Boltzmann transport equation. The thermal conductivity varies non-monotonically with mass ratio, with a maximum value that is four times higher than that of a monatomic semiconductor of the same density. The very high thermal conductivities are attributed to a reduction in the scattering of optical phonons when the acoustic-optical frequency gap in the phonon dispersion approaches the maximum acoustic phonon frequency. The model system predictions compare well to predictions for real compound semiconductors under appropriate scaling, suggesting a universal behavior and a strategy for efficient screening of materials for high thermal conductivity.
TaS2 nanosheet-based room-temperature dosage meter for nitric oxide
Authors: He Qiyuan , Ma Qinglang , Chen Bo , Yin Zongyou , Zeng Zhiyuan , Wu Shixin , Cao Xiehong , Kong Xingyi , Zhang Hua
Published: August 2014

A miniature dosage meter for toxic gas is developed based on TaS2 nanosheets, which is capable of indicating the toxic dosage of trace level NO at room temperature. The TaS2 film-based chemiresistor shows an irreversible current response against the exposure of NO. The unique non-recovery characteristic makes the TaS2 film-based device an ideal indicator of total dosage of chronicle exposure.
Microstructure and dielectric properties of (Nb + In) co-doped rutile TiO2 ceramics
Authors: Li Jinglei , Li Fei , Zhuang Yongyong , Jin Li , Wang Linghang , Wei Xiaoyong , Xu Zhuo , Zhang Shujun
Published: August 2014

The (Nb + In) co-doped TiO2 ceramics recently attracted considerable attention due to their colossal dielectric permittivity (CP) (∼100,000) and low dielectric loss (∼0.05). In this research, the 0.5 mol. % In-only, 0.5 mol. % Nb-only, and 0.5–7 mol. % (Nb + In) co-doped TiO2 ceramics were synthesized by standard conventional solid-state reaction method. Microstructure studies showed that all samples were in pure rutile phase. The Nb and In ions were homogeneously distributed in the grain and grain boundary. Impedance spectroscopy and I-V behavior analysis demonstrated that the ceramics may compose of semiconducting grains and insulating grain boundaries. The high conductivity of grain was associated with the reduction of Ti4+ ions to Ti3+ ions, while the migration of oxygen vacancy may account for the conductivity of grain boundary. The effects of annealing treatment and bias filed on electrical properties were investigated for co-doped TiO2 ceramics, where the electric behaviors of samples were found to be susceptible to the annealing treatment and bias field. The internal-barrier-layer-capacitance mechanism was used to explain the CP phenomenon, the effect of annealing treatment and nonlinear I-V behavior for co-doped rutile TiO2 ceramics. Compared with CaCu3Ti4O12 ceramics, the high activation energy of co-doped rutile TiO2 (3.05 eV for grain boundary) was thought to be responsible for the low dielectric loss.