bluuebunny/crossref_metadata_2025 huggingface dataset:
Geste graphique et technicité
Authors: Hameau Philippe
Published: April 2013

L’une des particularités du motif peint sur une paroi est qu’il garde la mémoire du geste qui l’a produit. Toutefois, il n’est possible de restituer valablement ce geste qu’en contextualisant le motif, c’est-à-dire en invoquant les paramètres culturels (des circonstances de sa production à son choix) et physiques (les matériaux dont il est fait et sa morphologie) qui ont accompagné sa réalisation. On l’étudie donc dans le cadre d’une anthropologie des gestes associés aux expressions picturales du Néolithique, sachant qu’avec le recul du temps, il nous faudra préalablement présenter des paramètres tels que les contraintes culturelles qui président à l’emplacement des figures et les pratiques rituelles à l’origine de l’expression graphique, sans oublier la topographie des parois et des sites. En effet, le scripteur perçoit, s’adapte et agit en fonction de cet environnement spatial et social. Quelques stratégies culturelles sont évoquées ici : l’attention portée à la microtopographie de la paroi selon les signes à tracer, le respect de certains des critères qui déterminent le choix du site comme l’humidité des lieux et la teinte orangée des parois, la volonté de peindre aux limites de l’accessibilité du site et de la paroi, l’usage d’outils-traceurs augmentant les capacités du corps. L’efficacité du geste consiste alors dans la réalisation d’un motif porteur de sens parce qu’il est en adéquation avec la perception culturellement orientée des caractéristiques de son support. De cette analyse structurée sur un terrain ancien, on tire des éléments de réflexion anthropologique pour d’autres pratiques graphiques, notamment contemporaines et urbaines (tags, street art, etc.)
Suivre les actions de l'autre
Authors: Voilmy Dimitri
Published: April 2013

Les salles de classe se caractérisent par des pratiques organisationnelles établies et sont des environnements riches en technologies matérielles. Un outil tel que le tableau soutient l’activité en classe, et est l’objet vers lequel les participants à l’événement que constitue la classe coordonnent leur attention mutuelle. L’organisation locale de l’interaction en classe est accomplie à la fois par le parler et par les regards, les gestes, la posture corporelle. De quelle manière la conduite incarnée est-elle rendue observable pour la gestion endogène (émique) de l’activité ? Comment le fait de pouvoir suivre et comprendre les gestes des autres permet-elle la co-orientation vers un même moment interactionnel ? Cet article examine un moment de transition entre deux activités avec le tableau interactif pendant lequel l’institutrice manipule l’outil et interroge les élèves concernant la consigne et l’utilisation du tableau pour l’activité future. Cette situation concrète d’enseignement a été enregistrée selon la perspective de l’analyse vidéo de l’ordre local en classe, dont l’exigence de base est de préserver les ressources exploitées et mobilisées par les participants à l’interaction. Nous nous intéressons à la manière dont les élèves suivent les différentes actions de l’institutrice, lèvent la main pour se présélectionner, commencent à répondre pour attirer l’attention, et pointent vers le tableau de manière publiquement intelligible. Nous interrogeons la manière dont, à travers leur conduite incarnée (verbale et gestuelle), les enfants montrent leurs orientations vers, et leur capacité à gérer, l’observabilité de leur conduite en classe.
Le chant comme geste vocal
Authors: Gervasi Flavia
Published: April 2013

Dans cet article nous cherchons à dégager les critères opératoires qui régissent un répertoire de chants de travail du sud de l’Italie en reportant notre regard analytique sur la perception physique – et pas seulement acoustique et « proprement musicale » – qu’en ont les tenants de la tradition. Afin de mener à bien notre étude, ce qui nous intéresse est ainsi la compréhension du mode d’être du sujet dans son environnement, en cherchant à découvrir comment l’interaction d’un corps avec son espace physique et social peut être porteur d’un sens, du point de vue de la construction et de la mise en oeuvre d’une pratique vocale. L’étude des références expressives et conceptuelles, ainsi que des patterns de comportements corporels, devrait nous permettre de comprendre le principe constructeur à la base de la performance des arie dites « deltrainieri », chantées par les paysans d’un village au sud de l’Italie appelé Martano.
Lazer e turismo: Visitas ao Observatório Abrahão de Moraes/IAG-USP (SP, Brasil)
Authors: Tomanik Geny Brillas , Cavenaghi Airton José
Published: April 2013

Esta pesquisa exploratória, de caráter qualitativo, tem como objetivo analisar as atividades de lazer e de turismo promovidas pelo Observatório Abrahão de Moraes (OAM), situado na região de Valinhos e Vinhedo (São Paulo, Brasil), que o consideram um atrativo turístico. As suas principais atividades são direcionadas às pesquisas científicas em astronomia e astrobiologia. Além disso, abre as suas portas ao público local e turistas, funcionando como relevante difusor de conhecimento astronômico. Objetiva-se, ainda, investigar a relevância do equipamento para a comunidade local, a sua visibilidade, além da hospitalidade ali exercida. A metodologia utilizada foi a pesquisa bibliográfica exploratória com enfoque no lazer, turismo e hospitalidade, e também a coleta documental de dados nos sítios eletrônicos. A pesquisa qualitativa fundamenta-se em entrevistas pessoais entre membros selecionados da equipe do OAM; gestores locais das áreas de turismo e/ou cultura; residentes locais e visitantes. Conclui-se que o equipamento é um atrativo turístico e espaço de lazer com grande potencial a ser mais desenvolvido, em razão da sua reduzida visibilidade, e que o atendimento ao público é muito bem avaliado pelos visitantes.
Relatório anual da revista
Authors: Anjos Sara Joana Gadotti dos , Corrêa Cynthia Harumy Watanabe
Published: April 2013

A última edição do ano da RBTur encerra com o Relatório Anual da Revista contendo a listagem completa de avaliadores, autores e informações editoriais de 2012.
6th International Conference on Responsible Tourism in Destination
Authors: Goodwin Harold , Font Xavier , Aldrigui Mariana
Published: April 2013

Conference Report

June 18 to 20, 2012

University of São Paulo – Brasil
Composite Right‐/Left‐Handed Transmission Line Metamaterials
Authors: Durán‐Sindreu Miguel , Naqui Jordi , Selga Jordi , Vélez Paris , Bonache Jordi , Martín Ferran
Published: April 2013

This article is focused on transmission line metamaterials, that is, metamaterials implemented by loading a host transmission line with reactive elements (capacitors, inductors, and/or resonators). It is mainly devoted to transmission line metamaterials exhibiting a composite right‐/left‐handed (CRLH) behavior, that is, supporting left‐handed (or backward) wave propagation in certain frequency bands and right‐handed (or forward) wave propagation in other frequency intervals. The analysis of these transmission lines (on the basis of the equivalent circuit models) and their main relevant applications are reviewed in this article.
Solution‐Diffusion Processes
Authors: Verliefde Arne R. D. , Van der Meeren Paul , Van der Bruggen Bart
Published: April 2013

The solution‐diffusion model has been widely used to describe solute and solvent transport through high pressure membranes. The main proposition of the theory is that the driving force is a gradient in (electro)chemical potential. This makes the theory applicable to all dense membrane processes because common membrane driving forces such as gradients in temperature, electromotive forces, concentration, and pressure can in fact be translated to (electro)chemical potential gradients. This review describes the origin of the solution‐diffusion model and the premises on which it was built. The theory is derived in more detail for reverse osmosis and the strong and weak points are highlighted. Possible adaptations such as convection–diffusion models and extended Nernst–Planck approaches are elaborated on.
Fouling in Membrane Bioreactors
Authors: Kola Anusha , Ye Yun , Chen Vicki
Published: April 2013

Membrane bioreactors (MBRs) have become increasingly popular in water and wastewater treatment as an alternative to the conventional activated sludge process. However, membrane fouling is still a key issue in the MBR system that significantly influences the system operation and maintenance cost. In this paper, key factors influencing membrane fouling are reviewed and discussed. The fundamental fouling mechanisms of the MBR system are explored via analyzing different fractions of the MBR feed solution and their corresponding fouling propensities. With the aid of fouling layer fractionation and advanced characterization techniques, the preferential deposition of different foulants is clearly highlighted. Furthermore, different operation conditions and parameters for fouling limitation and removal are reviewed and compared.
Micro‐Engineered Membranes
Authors: van Rijn Cees J. M.
Published: April 2013

Microengineering refers to the technology and practice of making three‐dimensional structures and devices, with dimensions at the order of micrometers in particular monocrystalline silicon substrates. An overview of techniques is presented. Next, membranes are designed and made, with a number of relevant microengineering techniques, for the formation of micro‐ and nanopores in a thin, but strong membrane structure. Finally, a number of applications are being discussed.
Nanofiltration
Authors: Van der Bruggen Bart
Published: April 2013

Nanofiltration (NF) is, formally, the pressure‐driven membrane process that fills the gap between reverse osmosis (RO) and ultrafiltration (UF). Because the name of the process was introduced and accepted rather late (in the 1980s), the process boundaries are not well defined, so that NF has features of both neighboring processes, combined with the process' own specificities. This transitional profile makes NF to an exceptionally interesting technology, particularly because it operates in the range of applications for removal of small organic solutes in the range of 200–2000 g/mol, and (partial) removal of inorganic ions, with the additional potential of separating mono‐ and multivalent ions. The combination of the dual nature of NF as a process intermediate to RO and UF and its specific challenges and opportunities are shown in this article. Membrane materials and synthesis methods are described in brief and to the extent that they differ from general methods of membrane manufacturing. Properties of membranes and membrane materials prove to be necessary for understanding the performance of filtration and separation, which will be shown through a combined approach based on experimental insights and modeling.

Solvent‐resistant nanofiltration (SRNF) is described separately as one of the newly emerging membrane processes, with a very large potential for separations in the chemical, petrochemical, pharmaceutical, as well as food and related industries. The performance of SRNF will be related to physicochemical parameters, which eventually should allow prediction of the process performance.

For aqueous applications, special attention is paid to membrane fouling in NF, which remains one of the main points of attention. The approach followed here is that of the resistance‐in‐series model, in which flux decline is split up into its different contributing effects, aiming at identifying and controlling the most significant contributors. It is suggested that adsorption of organic solutes and pore blocking are potentially the most important mechanisms of flux decline that are difficult to control.

The most important applications of NF (in aqueous solutions) are outlined: production of drinking water (with focus on newly emerging applications such as the removal of a wide range of micropollutants), applications in wastewater treatment and water recycling, and the use of NF in fractionation processes.

Finally, a brief indication is given of the challenges for NF and NF membranes that remain to be solved.
Membrane Reactors, Applications
Authors: Basile Angelo , Liguori Simona , Iulianelli Adolfo
Published: April 2013

The development of new value‐added products and the application of innovative technologies are attracting considerable attention in the context of modernization of the oil‐refining, chemical, and petrochemical industries,involving the treatment of aromatic hydrocarbons and olefins and the production of green energy while preserving the environment. Membrane technology can constitute a key challenge in the promotion of scale‐up from fundamental research to large‐scale industry owing to the offer of attractive opportunities in the design, rationalization, and optimization of, for example, energy production. Different operations can be integrated in the same industrial field, leading to important benefits of product quality, plant compactness, and lower environmental impact. As a specific case, high competitiveness and innovation are expected from integrated membrane reactor technology in many segments of conventional industrial activities, especially in areas such as the production of hydrogen from the reforming of hydrocarbons and alcohols or from the exploitation of new greener and alternative energy sources such as biofuels.
Gas Separation, Applications
Authors: Brunetti Adele , Barbieri Giuseppe , Drioli Enrico
Published: April 2013

Membrane‐based gas separation (GS) systems are today widely accepted and, in some cases, used as a unit operation for generation, separation, and purification of gases in gas, chemical, petroleum, and allied industries. There are several fields of application of membrane GS, and several membrane materials and membrane modular solutions are available today for the various fields of interest. However, the growth of large‐scale industrial applications is still far from reaching the real potential that membrane GS can offer. Together with the investigation of new materials with improved properties, a key role for widespread use of this technology is represented by the development of new knowledge for better utilization of the unit operations already available on the market in integrated membrane systems combining various membrane operations in the industrial process. The role of membrane engineering is crucial to overcome this hurdle.

This article describes the application fields of membranes in GS. In addition, it addresses the critical needs in the development of this technology and some of the factors that are impeding the growth of GS membranes. After an overview on the membrane materials and membrane modules now available on the market, or being studied in the laboratory, a description of the main GS processes involving membranes is presented, as well as a comparison with traditional technologies currently in use.
Analytical Applications of Membranes
Authors: Bruening Merlin L.
Published: April 2013

Roles of membranes in analytical chemistry range from creating potentials in ion‐selective electrodes to catalyzing protein digestion before mass spectrometry. This article focuses on membrane‐based analyte extraction and also briefly discusses recent catalytic membranes that facilitate analyte derivatization or digestion. Membrane‐based liquid‐liquid extraction avoids mixing and subsequent collection of the two phases and the recent development of hollow‐fiber microextraction is particularly attractive for small‐volume, potentially‐automated analyses. Microdialysis sampling is now a widespread tool for analyte collection from a variety of tissues, while membrane introduction mass spectrometry combined with miniaturized mass spectrometers facilitates remote or portable environmental analyses. Derivatization of membranes affords adsorptive materials for solid‐phase extraction. In particular, growth of functionalized polymer brushes in pores yields membrane adsorbers that capture tagged proteins. Moreover, simple methods for enzyme adsorption in porous membranes give reactors that catalyze rapid proteolysis for mass spectrometry. In addition to their history in ion‐selective electrodes and filtration, future membranes will play a significant role in sample purification and derivatization because they provide convenient methods for rapidly concentrating or modifying small‐volume samples.
Influence of Matrix Strength and Volume Fraction of Mg‐PSZ on the Cyclic Deformation Behavior of Hot Pressed TRIP/TWIP‐Matrix Composite Materials
Authors: Glage Alexander , Weigelt Christian , Räthel Jan , Biermann Horst
Published: April 2013

Particle reinforced metal matrix composites (MMCs) based on high‐alloyed CrMnNi steels and partially stabilized zirconia (Mg‐PSZ) are produced using the hot pressing technique. The resulting materials differ in the chemical composition of the high‐alloyed steel matrix and volume fraction of Mg‐PSZ. The change of chemical composition has a substantial influence on the austenite stability and stacking fault energy, triggering different deformation mechanisms in terms of the deformation‐induced transformation of austenite into ϵ‐ and/or α′‐martensite and/or deformation‐induced twinning. MMCs with 5 and 10 vol% Mg‐PSZ as well as unreinforced steels are investigated in total strain controlled fatigue tests. The focus of this work is to clarify the effect of the matrix strength and Mg‐PSZ volume fraction on the cyclic deformation behavior. This includes the discussion of cyclic hardening and/or softening during fatigue tests, consequences on the fatigue life times and deformation‐induced microstructures.
Optimization‐based framework for computer‐aided molecular design
Authors: Samudra Apurva P. , Sahinidis Nikolaos V.
Published: April 2013

A new framework to automate, augment, and accelerate steps in computer‐aided molecular design is presented. The problem is tackled in three stages: (1) composition design, (2) structure determination, and (3) extended design. Composition identification and structure determination are decoupled to achieve computational efficiency. Using approximate group‐contribution methods in the first stage, molecular compositions that fit design targets are identified. In the second stage, isomer structures of solution compositions are determined systematically, and structure‐based property corrections are used to refine the solution pool. In the final stage, the design is extended beyond the scope of group‐contribution methods by using problem‐specific property models. At each design stage, novel optimization models and graph theoretic algorithms generate a large and diverse pool of candidates using an assortment of property models. The wide applicability and computational efficiency of the proposed methodology are illustrated through three case studies. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3686–3701, 2013
Silk‐inspired polyurethane containing GlyAlaGlyAla tetrapeptide. II. physical properties and structure
Authors: Liu Hongtao , Zhou Jiangang , Liu Xiuying , Zuo Danying , Gu Shaojin , Xu Weilin
Published: April 2013

Biomedical polyurethane (BPU) and silk fibroin have similarly molecular architecture in their primary and aggregate structure, both of which have amide bonds and microphase separation, and they have been employed as scaffold materials for biomedical applications. Based on this, as the featured peptide sequence of silkworm silk fibroin, GlycineAlanineGlycineAlanine (GlyAlaGlyAla) tetrapeptide was synthesized by using traditional liquid‐phase peptide synthesis method with Boc‐protected glycine and alanine as starting materials, and was transformed to its derivative with two amine‐terminated functional groups. The derivative was introduced as a chain extender into the backbone to form the hard segment of a silk‐inspired PU with urea‐linkage. Related measurements show that molecular weight of the synthesized silk‐inspired PU ranged from 13,000 to 15,000. Fourier transform infrared (FTIR) absorption bands of Amides I and II are at 1651 cm−1 and 1534 cm−1, and Raman absorption band of Amide III is at 1302 cm−1. UV‐Vis absorption peak of the silk‐inspired PU is at 266 nm. This new concept and strategy may allow the fabrication of a new class of thermoplastic polyurethane elastomers to mimic the structure and properties of silk fibroin of silkworms and spiders. Information provided by this study may be used to better understand the correlation between the natural and man‐made materials. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of clay type and polymer matrix on microstructure and tensile properties of PLA/LLDPE/clay nanocomposites
Authors: As'habi Ladan , Jafari Seyed Hassan , Khonakdar Hossein Ali , Kretzschmar Bernd , Wagenknecht Udo , Heinrich Gert
Published: April 2013

Polylactide (PLA)/linear low‐density polyethylene (LLDPE), (PLA/LLDPE), blends and nanocomposites were prepared by melt mixing process with a view to fine tune the properties. Two different commercial‐grade nanoclays, Cloisite® 30B (30B) and Cloisite® 15A (15A) were used. A terpolymer of ethylene, butylacrylate (BA) and glycidylmethacrylate (GMA) was used as a reactive compatibilizer. The influence of type of clay on the morphology and mechanical properties of two PLA‐rich and LLDPE‐rich blend systems was studied. Morphological analysis using X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy revealed that the organoclay layers were dispersed largely at the interface of PLA/LLDPE. Decreasing the PLA content changed the morphology from droplet‐in matrix to coarse co‐continuous. In comparison with 30B, due to less affinity of 15A towards compatibilizer and PLA phase, the reduction of the size of dispersed phase was less than that of the equivalent 30B composites. The mechanical results demonstrated that the composites containing both types of organoclay exhibited higher modulus but lower elongation and tensile strength as compared to the neat blends. The injection molded nanocomposites were shown to have the sequential fracture behavior during tensile test. The tensile testing results on the neat blends and nanocomposites showed significant increase in elongation at break and decrease in the modulus as compared with the neat PLA. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 749‐758, 2013
MWNT‐filled PC/ABS blends: Correlation of morphology with rheological and electrical response
Authors: Monemian Seyedali , Jafari Seyed Hassan , Khonakdar Hossein Ali , Goodarzi Vahabodin , Reuter Uta , Pötschke Petra
Published: April 2013

A systematic study was done on morphological, electrical and rheological behavior of co‐continuous or dispersed‐type polycarbonate (PC)/acrylonitrile‐styrene‐butadiene (ABS) blends, containing different amounts of multiwalled carbon nanotubes (MWNT). The MWNTs gave substantial electrical conductivities to these nanocomposites at very low concentrations, owing to the effective melt processing method. Because of selective localization of MWNTs in the PC phase, along with double percolation phenomenon, the blend with co‐continuous morphology showed a lower electrical and rheological percolation threshold, higher melt viscosity and elasticity, as compared to the system with dispersed morphology. The morphology of both the blend systems was refined as a result of MWNTs incorporation but the morphology type remained unchanged. A typical role of compatibilizer in refining blend morphology was observed in both the systems. The electrical conductivity of the system filled with MWNTs in presence of compatibilizer, was lower than the systems filled with MWNTs only, which was attributed to role of compatibilizer in directing a part of MWNTs from PC matrix toward ABS phase. With increasing compatibilizer/MWNTs ratio, the influence of compatibilizer on morphology refinement and conductivity reduction was intensified. By comparing TEM micrograph of PC/SAN/MWNTs with that of PC/ABS/MWNTs, it was revealed that small portion of MWNTs was also located on polybutadiene rubber fraction of ABS. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 739‐748, 2013
Synchronization Criteria for Neutral Complex Dynamic Networks with Interal Time‐Varying Coupling Delays
Authors: Duan Wenyong , Du Baozhu , You Jing , Zou Yun
Published: April 2013

This paper deals with a synchronization problem of a class of neutral‐type complex dynamic networks with interval time‐varying coupling delays under a pair of nonlinear constraints. Some delay‐dependent synchronization criteria are derived in the form of linear matrix inequalities (LMIs) based on a modified Lyapunov‐Krasovskii (LK) functional approach. By a convexity analysis of the matrix function, a free‐weighting matrix method is employed for the purpose of reducing the conservatism of the existing results. Two illustrative examples are given to demonstrate the effectiveness of the proposed approach.
Spitzendruck bei Sondierungen. Einflußgrößen und Prognose
Authors: Schumacher L.
Published: April 2013

Im Beitrag werden wesentliche, spitzendruckbestimmende Einflußgrößen aufgezeigt, die Möglichkeit der Bestimmung des Spitzendrucks aus Rammsondierungen dargestellt und ein Berechnungsalgorithmus zur Prognose des Spitzendrucks abgeleitet. Der Berechnungsalgorithmus basiert auf einer multiplen nichtlinearen Regressionsanalyse.
Copper‐Catalyzed Amination of Aryl Halides with Aqueous Ammonia under Mild Conditions
Authors: Quan Zhengjun , Xia Haidong , Zhang Zhang , Da Yuxia , Wang Xicun
Published: April 2013

A Cu(I) generated in situ from CuSO4·5H2O/sodium ascorbate catalyzed cross‐coupling reaction of aryl halides with aqueous ammonia for the synthesis of primary aromatic amines has been developed. Key to the success included the application of aqueous ammonia under a homogeneous condition.
Copper Hydride‐Catalyzed Conjugate Reduction‐Aldol Addition Domino Reaction of α,β‐Unsaturated Carboxylates with Ketones
Authors: Li Zengchang , Jiang Lan , Li Zhengning , Chen Huiying
Published: April 2013

Copper hydride‐catalyzed conjugate reduction‐intermolecular aldol addition domino reactions were realized using α,β‐unsaturated carboxylates as hydride acceptors and a silane as the reducing reagent. High diastereoselectivities were achieved with 4,5‐bis(diphenylphosphino)‐9,9‐dimethylxanthene as the ligand and tert‐butyl acrylate as the hydride acceptor.
Design, Synthesis, and Biological Evaluation of Novel Dual Inhibitors of Secretory Phospholipase A2 and Sphingomyelin Synthase
Authors: Gao Xing , Gong Haojun , Men Peng , Zhou Lu , Ye Deyong
Published: April 2013

A novel series of eight SMS and sPLA2 dual inhibitors containing indole and α‐amino cyanide fragments of different length and substitution position was synthesized and evaluated by three different in vitro assays. Biological evaluation showed that all compounds provided inhibitory effects against SMS (about 50% inhibition at 100 µmol/L) and sPLA2 (14–32 µmol/L). All the compounds had the SMS activity better than the positive control compound D609 in SMS2 homogenate, with compounds 5b and 5e ideal for liver homogenate and SMS2 high expression cell homogenate, respectively.
A parallel scheme for accelerating parameter sweep applications on a GPU
Authors: Ino Fumihiko , Shigeoka Kentaro , Okuyama Tomohiro , Motokubota Masaya , Hagihara Kenichi
Published: April 2013

This paper proposes a parallel scheme for accelerating parameter sweep applications on a graphics processing unit. By using hundreds of cores on the graphics processing unit, we found that our scheme simultaneously processes multiple parameters rather than a single parameter. The simultaneous sweeps exploit the similarity of computing behaviors shared by different parameters, thus allowing memory accesses to be coalesced into a single access if similar irregularities appear among the parameters’ computational tasks. In addition, our scheme reduces the amount of off‐chip memory access by unifying the data that are commonly referenced by multiple parameters and by placing the unified data in the fast on‐chip memory. In several experiments, we applied our scheme to practical applications and found that our scheme can perform up to 8.5 times faster than a naive scheme that processes a single parameter at a time. We also include a discussion on application characteristics that are required for our scheme to outperform the naive scheme. Copyright © 2013 John Wiley & Sons, Ltd.
Heterobimetallic Rare Earth–Lithium Complexes with Fewer Than Three Binaphtholates
Authors: Sircoglou Marie , Yang Jing , Guillot Régis , Bezzenine‐Lafollée Sophie , Gandon Vincent
Published: April 2013

Heterobimetallic rare earth–alkali metal binaphtholates (REMBs) are exquisite catalysts for asymmetric synthesis (Shibasaki catalysts). All solid‐state structures reported so far correspond to the general formula M3RE[(S)‐binolate]3 (RE/M/B = 1:3:3 stoichiometry). We have synthesized and characterized crystallographically new complexes of this category, namely Li3RE[(S)‐binolate]3·xTHF [RE = Sc (2), Sm (3)] and Li3Nd[(S)‐binolate]3·6THF·LiCl (4). The latter is the first reported adduct between a REMB and LiCl. We have also crystallized a rare type of REMB of 1:2:2.5 stoichiometry: Li4Sm2[(S)‐binolate]5·6THF·2H2O (5). Such a complex has only one precedent in the literature. The use of (S)‐3,3′‐dimesityl‐1,1′‐binaphthyl‐2,2′‐diol (6) as ligand precursor allowed us to obtain the first X‐ray structures of unprecedented REMBs of 1:1:1 and 1:1:2 stoichiometries: {[(S)‐6]RECl2(THF)2}[Li(THF)2] [RE = Y (7), Sm (8)] and LiY[(S)‐6]2·2THF (9).
A Mild and Efficient Three–Component Synthesis of Secondary and Tertiary Homoallylic Hydrazides
Authors: Lee Bum Seok , Jang Doo Ok
Published: April 2013

A three‐component reaction that involved a carbonyl compound, benzoylhydrazine, allyl bromide, and indium in the presence of readily available Zn(ClO4)2·6H2O was developed for the syntheses of secondary and tertiary homoallylic hydrazides. Excellent chemoselectivities and diastereoselectivies were observed. Aldehydes as well as acyclic and cyclic ketones were well‐suited to the reaction conditions and provided secondary and tertiary homoallylic hydrazides in excellent yields.
A simplified methodology for estimating solar spectral influence on photovoltaic energy yield using average photon energy
Authors: Ishii Tetsuyuki , Otani Kenji , Itagaki Akihiko , Utsunomiya Kenji
Published: April 2013

Nowadays, investors, customers, and even suppliers focus on the bankability of photovoltaic (PV) technologies. However, few studies have investigated the annual net effect of solar spectrum. In this study, we estimate the net effect of the solar spectrum on the annual energy yield of c‐Si and a‐Si modules by two parameters. One parameter is a direct calculation from spectral factor (SF). The other parameter uses average photon energy (APE) and a regression line or curve. The estimations by the two parameters are quite consistent, whereas there is 1.2% difference between the estimations at most. Therefore, APE would be a useful index to quantify the effect of the solar spectrum.
Rational Design of Double‐Check Mercury Ion Chemosensors Based on Photochromic Compounds
Authors: Jin Jiayu , Li Xin , Zhang Junji , Zhao Ping , Tian He
Published: April 2013

A new photochromic compound, S1, containing a trans‐cis photoisomerizable unit and a mercury detecting chemosensor unit, has been designed and synthesized. S1 displayed dramatic selectivity for mercury ions over other ions, through fluorescence intensity measurement. In addition, in the photostationary state, a colorimetric response to mercury ions was also achieved. The fluorescence turn‐off of S1 by mercury ions was defined as the first check, while mercury‐induced colorimetric variation in the photostationary state was set as the second check. Thus, a double‐check mercury chemosensor can be achieved.
The osteogenic differentiation of mesenchymal stem cells by controlled cell–cell interaction on micropatterned surfaces
Authors: Wang Xinlong , Song Wei , Kawazoe Naoki , Chen Guoping
Published: April 2013

Cell–cell interaction plays an important role in the control of cell functions. The precise control of cell–cell interaction will provide a useful tool to elucidate its influence on stem cell differentiation. In this study, four types of micropatterned surfaces were prepared by ultraviolet photolithography to investigate the effect of cell–cell interaction on the osteogenic differentiation of human mesenchymal stem cells (MSCs). Single MSCs adhered on the micropatterned surfaces following the micropatterns. Single cells on the isolated, barbell, linear, and honeycomb dot micropatterns had zero, one, two, and three cell–cell interaction partners, respectively. The number of cell–cell interaction of single MSCs was controlled by the different micropatterns, which showed evident effects on actin filament structure assembly and osteogenic differentiation of MSCs. MSCs with two and three interaction partners showed a significantly higher rate of osteogenic differentiation than did isolated single cells and cells with only one interaction partner. Thus, the osteogenic differentiation of MSCs was enhanced with increased cell–cell interaction. These results highlight the importance of cell–cell interaction in stem cell differentiation. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 3388–3395, 2013.
JACOB: An enterprise framework for computational chemistry
Authors: Waller Mark P. , Dresselhaus Thomas , Yang Jack
Published: April 2013

Here, we present just a collection of beans (JACOB): an integrated batch‐based framework designed for the rapid development of computational chemistry applications. The framework expedites developer productivity by handling the generic infrastructure tier, and can be easily extended by user‐specific scientific code. Paradigms from enterprise software engineering were rigorously applied to create a scalable, testable, secure, and robust framework. A centralized web application is used to configure and control the operation of the framework. The application‐programming interface provides a set of generic tools for processing large‐scale noninteractive jobs (e.g., systematic studies), or for coordinating systems integration (e.g., complex workflows). The code for the JACOB framework is open sourced and is available at: www.wallerlab.org/jacob. © 2013 Wiley Periodicals, Inc.
Computational design of S‐nitrosothiol “click” reactions
Authors: Talipov Marat R. , Khomyakov Dmitry G. , Xian Ming , Timerghazin Qadir K.
Published: April 2013

To address a long‐standing problem of finding efficient reactions for chemical labeling of protein‐based S‐nitrosothiols (RSNOs), we computationally explored hitherto unknown (3+2) cycloaddition RSNO reactions with alkynes and alkenes. Nonactivated RSNO cycloaddition reactions have high activation enthalpy (>20 kcal/mol at the CBS‐QB3 level) and compete with alternative S—N bond insertion pathway. However, the (3+2) cycloaddition reaction barriers can be dramatically lowered by coordination of a Lewis acid to the N atom of the —SNO group. To exploit this effect, we propose to use reagents with Lewis acid and a strain‐activated carbon–carbon multiple bond linked by a rigid scaffold, which can react with RSNOs with small activation enthalpies (∼5 kcal/mol) and high reaction exothermicities (∼40 kcal/mol). The proposed efficient RSNO cycloaddition reactions can be used for future development of practical RSNO labeling reactions. © 2013 Wiley Periodicals, Inc.
Attractive electron–electron interactions within robust local fitting approximations
Authors: Merlot Patrick , Kjærgaard Thomas , Helgaker Trygve , Lindh Roland , Aquilante Francesco , Reine Simen , Pedersen Thomas Bondo
Published: April 2013

An analysis of Dunlap's robust fitting approach reveals that the resulting two‐electron integral matrix is not manifestly positive semidefinite when local fitting domains or non‐Coulomb fitting metrics are used. We present a highly local approximate method for evaluating four‐center two‐electron integrals based on the resolution‐of‐the‐identity (RI) approximation and apply it to the construction of the Coulomb and exchange contributions to the Fock matrix. In this pair‐atomic resolution‐of‐the‐identity (PARI) approach, atomic‐orbital (AO) products are expanded in auxiliary functions centered on the two atoms associated with each product. Numerical tests indicate that in 1% or less of all Hartree–Fock and Kohn–Sham calculations, the indefinite integral matrix causes nonconvergence in the self‐consistent‐field iterations. In these cases, the two‐electron contribution to the total energy becomes negative, meaning that the electronic interaction is effectively attractive, and the total energy is dramatically lower than that obtained with exact integrals. In the vast majority of our test cases, however, the indefiniteness does not interfere with convergence. The total energy accuracy is comparable to that of the standard Coulomb‐metric RI method. The speed‐up compared with conventional algorithms is similar to the RI method for Coulomb contributions; exchange contributions are accelerated by a factor of up to eight with a triple‐zeta quality basis set. A positive semidefinite integral matrix is recovered within PARI by introducing local auxiliary basis functions spanning the full AO product space, as may be achieved by using Cholesky‐decomposition techniques. Local completion, however, slows down the algorithm to a level comparable with or below conventional calculations. © 2013 Wiley Periodicals, Inc.
Impact of hospitalist communication‐skills training on patient‐satisfaction scores
Authors: O'Leary Kevin J. , Darling Tiffani A. , Rauworth Jennifer , Williams Mark V.
Published: April 2013

BACKGROUND

Hospital patient‐satisfaction scores now affect hospital payment, but little research addresses how hospitals or clinicians might improve performance.

OBJECTIVE

To assess the impact of a communication‐skills training program on patient satisfaction with doctor communication and overall hospital care.

DESIGN

Preintervention vs postintervention comparison of patient‐satisfaction scores. We designed a communication‐skills training program for hospitalists consisting of three 90‐minute sessions, based on a popular framework.

SETTING

Nonteaching hospitalist service in an urban academic hospital.

MEASUREMENTS

Doctor‐communication items from the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) and Press Ganey surveys, and HCAHPS overall hospital rating.

RESULTS

Overall, 61 (97%) of 63 hospitalists completed the first session, 44 (70%) completed the second session, and 25 (40%) completed the third session of the program. Patient‐satisfaction data was available for 278 patients during the preintervention period and 186 patients during the postintervention period. Two of the 3 HCAHPS and all 5 of the Press Ganey doctor‐communication items were rated higher during the postintervention period, but no result was statistically significant. Similarly, the overall hospital rating was higher during the postintervention period, but the result was not significant. Analyses based on level of hospitalist participation did not show significant differences.

CONCLUSIONS

Patient satisfaction did not significantly improve after a communication‐skills training program for hospitalists. Because of the small sample size, larger studies are needed to assess whether such a program might truly improve patient satisfaction. Journal of Hospital Medicine 2013;8:315–320. © 2013 Society of Hospital Medicine
Immersed stress method for fluid–structure interaction using anisotropic mesh adaptation
Authors: Hachem E. , Feghali S. , Codina R. , Coupez T.
Published: April 2013

This paper presents advancements toward a monolithic solution procedure and anisotropic mesh adaptation for the numerical solution of fluid–structure interaction with complex geometry. First, a new stabilized three‐field stress, velocity, and pressure finite element formulation is presented for modeling the interaction between the fluid (laminar or turbulent) and the rigid body. The presence of the structure will be taken into account by means of an extra stress in the Navier–Stokes equations. The system is solved using a finite element variational multiscale method. We combine this method with anisotropic mesh adaptation to ensure an accurate capturing of the discontinuities at the fluid–solid interface. We assess the behavior and accuracy of the proposed formulation in the simulation of 2D and 3D time‐dependent numerical examples such as the flow past a circular cylinder and turbulent flows behind an immersed helicopter in a forward flight. Copyright © 2013 John Wiley & Sons, Ltd.
A second‐order finite difference approximation for a mathematical model of erythropoiesis
Authors: Ackleh Azmy S. , Thibodeaux Jeremy J.
Published: April 2013

We present a second‐order finite difference scheme for approximating solutions of a mathematical model of erythropoiesis, which consists of two nonlinear partial differential equations and one nonlinear ordinary differential equation. We show that the scheme achieves second‐order accuracy for smooth solutions. We compare this scheme to a previously developed first‐order method and show that the first order method requires significantly more computational time to provide solutions with similar accuracy. We also compare this numerical scheme with other well‐known second‐order methods and show that it has better capability in approximating discontinuous solutions. Finally, we present an application to recovery after blood loss. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Trisomies 18 and 13: trends in prevalence and prenatal diagnosis – population based study
Authors: Tonks A. M. , Gornall A. S. , Larkins S. A. , Gardosi J. O.
Published: April 2013

Objective

The objective of this study was to determine trends in prenatal detection and current estimates of prevalence for trisomies 18 (T18) and 13 (T13) and their implications for screening policy.

Methods

We conducted a cohort study from a population‐based regional anomaly register covering 995 003 births (1995–2009).

Results

There were 786 affected cases. Total prevalence of T18 increased from 3.95 in 1995–1999 to 6.94 per 10 000 births in 2005–2009 (annual trend χ2 = 25.99, p < 0.001) and live birth prevalence, when adjusted for in utero attrition, increased from 1.47 to 2.30 per 10 000 births over the same time (annual trend χ2 = 6.36, p = 0.01). For T18 and T13 combined, the proportion of cases diagnosed by prenatal karyotype or suspected by ultrasound increased from 85.1% (165/194) in 1995–1999 to 95.2% (299/314) in 2005–2009 (p < 0.001). In 2005–2009, 50.3% of prenatal cytogenetic diagnoses for T18 and 38.5% of T13 were made after the discovery of first trimester ultrasound anomalies, and the majority, 56.4% (185/328), of affected pregnancies were karyotyped or had ended before 18 weeks.

Conclusion

T18 is increasing in prevalence because of maternal age and earlier surveillance. Prenatal diagnosis occurs mostly in the first trimester, without the intrinsic structures of a formal screening programme. These findings support the extension of first trimester combined screening to include T18 and T13. © 2013 Crown copyright.
A Poisson Regression Model to Examine Spatial Patterns in Antenatal Care Utilisation in Nigeria
Authors: Gayawan Ezra
Published: April 2013

Despite the benefits of antenat]al care to the mother and the child, it is available less often in sub‐Saharan Africa than in other regions. Coverage of at least four visits is lower, with a slower rate of increase, than in other regions of the world. Using data from 2008 Nigeria Demographic and Health Survey, we applied a Poisson regression model with geo‐additive predictors to analyse individual‐level and community‐level determinants of antenatal care utilisation and quantify district specific spatial effect. The spatial structure was modelled using conditional autoregressive prior, whereas the metrical covariates were assumed to be non‐linear. Findings reveal substantial spatial variation with a distinct north–south divide in antenatal care utilisation in Nigeria. The effects of mother's age at birth, partner's age, and marital duration were non‐linear, and utilisation was found to differ significantly between never‐married and ever‐married women respondents. Results further show that older women, particularly those above 35 years old, utilise antenatal care services during pregnancy more than the younger ones. Policymakers and public health providers need to put in more efforts to address these differentials as a minimum of four visits for antenatal care during pregnancy is required by all women in all parts of the country. Allocations for antenatal care services should also take into account the differentials so that those states lagging behind can be brought up, at least to scale with others. Copyright © 2013 John Wiley & Sons, Ltd.
Reduced graphene oxide micropatterns as an interface for adherent cells
Authors: Delle Lotta E. , Lanche Ruben , Law Jessica Ka‐Yan , Weil Maryam , Vu Xuan Thang , Wagner Patrick , Ingebrandt Sven
Published: April 2013

In the present study, reduced graphene oxide (rGO) is used as a biointerface for the investigation of cell adhesion of human embryonic kidney (HEK 293) cells. A fast, straightforward, and substrate‐independent soft lithography approach known as “Micromolding In Capillaries” (MIMIC) was utilized to pattern graphene oxide (GO) arrays. Large‐scale GO patterns with widths and distances in the micrometer range were obtained and were subsequently reduced to rGO via an environmentally‐friendly procedure using L‐ascorbic acid. Physical characterization of rGO patterns and cells was performed by optical microscopy, atomic force microscopy, and scanning electron microscopy. Impedance spectroscopy was used for the electrochemical characterization of GO before and after reduction. Cell adhesion and alignment was strong on the rGO micropatterns. In future assays, the rGO could combine two functions: cellular patterning and electrical interfacing of cells.

HEK 293 cells aligning on rGO micro patterns (SEM image)
Nanostructures and thin films of transparent conductive oxides studied by perturbed angular correlations
Authors: Barbosa M. B. , Gonçalves J. N. , Redondo‐Cubero A. , Miranda S. M. C. , Simon R. , Kessler P. , Brandt M. , Henneberger F. , Nogales E. , Méndez B. , Johnston K. , Alves E. , Vianden R. , Araújo J. P. , Lorenz K. , Correia J. G.
Published: April 2013

The versatility of perturbed angular correlations (PAC) in the study of nanostructures and thin films is demonstrated, namely for the specific cases of ZnO/CdxZn1−xO thin films and Ga2O3 powder pellets and nanowires, examples of transparent conductive oxides. PAC measurements as a function of annealing temperature were performed after implantation of 111mCd/111Cd (T1/2 = 48 min) and later compared to density functional theory simulations. For ZnO, the substitution of Cd probes at Zn sites was observed, as well as the formation of a probe‐defect complex. The ternary CdxZn1−xO (x = 0.16) showed good macroscopic crystal quality but revealed some clustering of local defects around the probe Cd atoms, which could not be annealed. In the Ga2O3 samples, the substitution of the Cd probes in the octahedral Ga‐site was observed, demonstrating the potential of ion‐implantation for the doping of nanowires.