bluuebunny/crossref_metadata_2025 huggingface dataset:
Spanish Validation of the Affective Neuroscience Personality Scales
Authors: Abella Víctor , Panksepp Jaak , Manga Dionisio , Bárcena Carmen , Iglesias José A.
Published: November 2011

The Affective Neuroscience Personality Scales have been designed to provide a personality assessment tool based on six distinct affective systems. The six neural systems involved were labeled PLAY, SEEK, CARE, FEAR, ANGER and SADNESS. Spirituality has been integrated into the questionnaire as a seventh dimension because, in opinion of Panksepp and his colleagues is one of the most interesting human emotion. The aim of the present paper was introduce the validation of the Spanish version of Affective Neuroscience Personality Scales and their first psychometric results in a sample of 411 college students. Participants completed the Spanish version of ANPS, just as a personality scale of five factors (NEO-FFI-R), and the Scales of Positive and Negative Affect (PANAS). The factor structure obtained and psychometric properties of the scales indicate that the Spanish version of the scales provides an effective tool to measure the seven dimensions of personality proposal in the original questionnaire.
Interference in Visual Perception by Verbal and Spatial Cognitive Activity
Authors: Pérez-Moreno Elisa , Conchillo Ángela , Recarte Miguel Ángel
Published: November 2011

In two experiments we tested the hypothesis that cognitive processing based on spatial imagery produces more deterioration of visual perception than cognitive processing based on verbal codes. So, we studied the effect on visual perception of two cognitive tasks, one of spatial imagery and the other a verbal task. In the first one, with 30 participants, we analyzed the mental load and ocular behaviors in both cognitive tasks. In the second experiment, with 29 participants, we studied the effect of both tasks on a visual search task, using a dual-task experimental paradigm. The verbal task presented higher mental load than the imagery task when both tasks were carried out with visual search task, and there was more deterioration in stimulus detection with the verbal task. We can conclude that: (1) cognitive tasks produce important deterioration in the capacities of visual search and identification of stimuli; (2) this deterioration has two components: (a) an inefficient search, associated with alterations of the gaze patterns while performing cognitive tasks, and (b) a general interference, nonspecific to spatial codes, in the process of identification of looked-at stimuli; (3) this cognitive interference is related to the mental load or effort required by the cognitive task.
Psychometric Properties of the Spanish Version of the Running Addiction Scale (RAS)
Authors: Sancho Antonio Zarauz , Ruiz-Juan Francisco
Published: November 2011

Despite the growing number of Spanish people who organize their lives to prepare and participate in marathons, bringing to it a very committed lifestyle that, sometimes, go in detriment of their own health. In this instrumental paper, we the adaptation and testing of the psychometric properties of theRunning Addiction Scale(RAS) in Spanish. To this end, we conducted two independent studies. The aim of the first was to present the first preliminary psychometric data (pilot sample of 174 marathon runners). Explained the process of translation, adaptation and content validity of items, we carried out a statistical analysis of these, an exploration of dimensional structure and analysis of the reliability of the instrument. In the second study (sample of 975 marathon runners), the aim was to analyze the internal structure of the instrument with confirmatory procedures. The Spanish version of the RAS showed acceptable levels of internal consistency, temporal stability, inter-item correlations and total scale score. Also provides evidences of construct validity. Slight differences were obtained by sex and age. These findings support the use of the Spanish version of RAS to assess individual differences in negative addiction to running.
A New Approach for Differential Item Functioning Detection Using Mantel-Haenszel Methods. The GMHDIF Program
Authors: Fidalgo Ángel M.
Published: November 2011

To date, the statistical software designed for assessing differential item functioning (DIF) with Mantel-Haenszel procedures has employed the following statistics: the Mantel-Haenszel chi-square statistic, the generalized Mantel-Haenszel test and the Mantel test. These statistics permit detecting DIF in dichotomous and polytomous items, although they limit the analysis to two groups. On the contrary, this article describes a new approach (and the related software) that, using the generalized Mantel-Haenszel statistic proposed by Landis, Heyman, and Koch (1978), permits DIF assessment in multiple groups, both for dichotomous and polytomous items. The program is free of charge and is available in the following languages: Spanish, English and Portuguese.
Testing Equivalence with Repeated Measures: Tests of the Difference Model of Two-Alternative Forced-Choice Performance
Authors: García-Pérez Miguel A. , Alcalá-Quintana Rocío
Published: November 2011

Solving theoretical or empirical issues sometimes involves establishing the equality of two variables with repeated measures. This defies the logic of null hypothesis significance testing, which aims at assessing evidence against the null hypothesis of equality, not for it. In some contexts, equivalence is assessed through regression analysis by testing for zero intercept and unit slope (or simply for unit slope in case that regression is forced through the origin). This paper shows that this approach renders highly inflated Type I error rates under the most common sampling models implied in studies of equivalence. We propose an alternative approach based on omnibus tests of equality of means and variances and in subject-by-subject analyses (where applicable), and we show that these tests have adequate Type I error rates and power. The approach is illustrated with a re-analysis of published data from a signal detection theory experiment with which several hypotheses of equivalence had been tested using only regression analysis. Some further errors and inadequacies of the original analyses are described, and further scrutiny of the data contradict the conclusions raised through inadequate application of regression analyses.
Thermal Sensitivity and Cardiovascular Reactivity to Stress in Healthy Males
Authors: Conde-Guzón Pablo Antonio , Bartolomé-Albistegui María Teresa , Quirós Pilar , Cabestrero Raúl
Published: November 2011

This paper examines the association of cardiovascular reactivity with thermal thresholds (detection and unpleasantness). Heart period (HP), systolic (SBP) and diastolic (DBP) blood pressure of 42 health young males were recorded during a cardiovascular reactivity task (a videogame based upon Sidman's avoidance paradigm). Thermal sensitivity, assessing detection and unpleasantness thresholds with radiant heat in the forearm was also estimated for participants. Participants with differential scores in the cardiovascular variables from base line to task ≥ P65 were considered as reactors and those how have differential scores ≤ P35 were considered as non-reactors. Significant differences were observed between groups in the unpleasantness thresholds in blood pressure (BP) but not in HP. Reactors exhibited significant higher unpleasantness thresholds than non-reactors. No significant differences were obtained in detection thresholds between groups.
Entrepreneurs' Perceptions of Business Networks: Does Gender Matter?
Authors: Dawson Chris , Fuller-Love Nerys , Sinnott Eileen , O'Gorman Bill
Published: November 2011

This paper looks at perceptions of entrepreneurial networks and the gender differences in networking. Women's networks tend to be more limited and to focus on family and friends, whereas male entrepreneurs generally have wider networks. The results of the study indicate that female entrepreneurs have a significantly more positive attitude towards networking, especially once the business has been established. The main benefits of networks for both men and women are better business contacts, sharing knowledge, problem solving and social aspects. Female entrepreneurs also believe that networks can provide them with learning opportunities and enable them to develop management skills.
Halen Môn: The Story of an ‘Uncomfortable’ Innovation
Authors: Carr James , Fuller-Love Nerys
Published: November 2011

Halen Môn is a family business in Anglesey, North Wales that began life in a saucepan of seawater on the Aga in the family kitchen. Today Halen Môn supplies Marks and Spencer, Waitrose and Harvey Nichols in the UK and their salt can also be found in 22 countries and some of the world's top restaurants. This case study views the development of this small business from the start-up phase to the present day. The resulting analysis illustrates the importance of three key elements of the innovation process: the need to develop an innovative organization; strategic leadership; and the formation of rich networks and strategic partnerships.
Entrepreneurial Teams and the Evolution of Networks: A Longitudinal Study
Authors: Arenius Pia , Laitinen Katja
Published: November 2011

To study the evolution of entrepreneurial networks, the authors followed a single firm for three years and collected data on changes in the discussion networks of the entrepreneurs. Whereas previous research has demonstrated the heterogeneity of networks between firms, this paper shows how entrepreneurs inside an organization differ in terms of networks and network resources. The authors combine the network data with qualitative interview data in an attempt to explain the observed individual-level differences. On the basis of the empirical material, they present a series of propositions linking individuals, entrepreneurial teams and network evolution.
Uso de reator air-lift em batelada para tratamento de efluentes de uma indústria de beneficiamento de coco
Authors: Oliveira Junior Antonio Martins , Nascimento Alisson Geraldo de Jesus , Silva Tamires Cruz Santos , Andrade Sonja França , Santos Edilson Jesus , Marques José Jailton
Published: November 2011

O coco pode ser utilizado como matéria prima de diversos produtos, tais como a água de coco que é a mais pura, nutritiva e completa bebida que a natureza produz nos trópicos. Todos os tipos de processos que envolvem o coco como matéria prima produzem uma série de resíduos, efluentes e emissões, que precisam ser tratados, devido à escassez de água em nosso planeta, bem como o maior rigor de leis ambientais. Para tal, o trabalho foi dividido em duas etapas: caracterização do efluente (Teor de óleos e graxas (TOG), Turbidez, e pH) e construção e avaliação de um Reator Air-Lift para utilização no tratamento de efluentes da indústria do coco, operando em regime de batelada. Observou-se que apenas os níveis de TOG e pH se mantiveram em conformidade com a lei. Apesar da significativa redução, o parâmetro turbidez não atendeu a resolução CONAMA.
Levantamento de perdas e desperdícios dos sistemas produtivos por meio da utilização dos coletores de dados
Authors: Fortunato Fernando Aparecido Pacheco da Silva , Vieira Junior Milton , Baptista Elesandro Antonio
Published: November 2011

Para garantir a sua sobrevivência e a respectiva competitividade no mercado, as empresas buscam oferecer produtos com elevados padrões de qualidade e custos acessíveis. As características apresentadas são o resultado da constante implementação de melhorias por parte da gerência ou pessoal responsável, com o intuito de reduzir ou eliminar perdas e tornar o sistema produtivo mais eficaz e eficiente. Mas para realizar a otimização de um processo ou operação, são necessárias informações que auxiliem na tomada de decisão. Por isso, este artigo tem o objetivo de apresentar, como os coletores de dados podem auxiliar na identificação, quantificação e redução das perdas nos sistemas produtivos.
Usando Realidade Virtual e Aumentada no Resgate e Valorização de Jogos Populares Antigos
Authors: Simi Steicy Kelly , Dias William Derek J. , Araújo Sidnei Alves de , Alves Wonder Alexandre Luz
Published: November 2011

O desenvolvimento de jogos eletrônicos está em constante expansão, fazendo com que surjam inovações e melhorias nos gráficos tridimensionais, áudio e realismo para imersão do usuário ao mundo virtual. A aplicação de Realidade Aumentada (RA) em jogos tem contribuído ativamente para esse processo. É evidente o crescimento do uso de RA no mercado mundial, visto que empresas como Nintendo, Sony e Microsoft, por exemplo, já disponibilizam em seus consoles Wii, PS3 e Xbox, respectivamente, interatividade através da aplicação dessa tecnologia. Neste trabalho explora-se a aplicação da Realidade Virtual e Aumentada no resgate e valorização de jogos populares. Para este propósito, foi desenvolvido um jogo denominado ARGame, que é uma versão eletrônica do antigo e popular “Jogo da velha”.
Avaliação da produção de bacitracina em diferentes temperaturas por Bacillus licheniformis (UCP 1016), utilizando meios alternativos contendo soro de leite
Authors: Alves da Silva Carlos Alberto , Sales Amanda Emanuele , Campos Takaki Galba Maria de
Published: November 2011

A bacitracina é um antibiótico poliênico produzido por diversas espécies de B. subtilis e B. licheniformis. O soro de leite é um subproduto da fabricação de queijos, que apresenta um alto valor nutritivo e é considerado um poluente extremamente problemático, devido à sua elevada carga orgânica e volume gerado. Foram realizados estudos para elaboração de meios alternativos para produção de bacitracina, utilizando soro de leite em substituição ao ácido glutâmico, e a adição de diferentes concentrações de glicose em diferentes temperaturas (28 e 37oC), sendo utilizada a detecção do antibiótico, pelo método biológico de formação de halos característicos. Os resultados obtidos demonstraram que a bacitracina produzida na concentração de 10g de glicose obteve o maior halo de inibição (16 mm) á 37 oC. A utilização do soro de leite em meios de produção, surge como uma nova alternativa de de descarte no meio ambiente desse rejeito industrial.
Avaliação do processo de desenvolvimento de um novo produto utilizando earned value management system
Authors: Cutovoi Iara Tonissi Moroni , Salles José Antonio Arantes
Published: November 2011

Retrata-se uma situação de integração do processo de desenvolvimento de produtos - PDP ao longo da cadeia de suprimentos por meio do fluxo de valor. Avalia-se um caso de aplicação de um modelo de PDP numa empresa de autopeças líder em seu segmento. A partir da aplicação do pensamento enxuto na cadeia de suprimentos, e da metodologia EMVS na análise de desempenho do PDP, é criado um Check List para evitar desperdícios no gerenciamento de projetos. Os resultados demonstram que a metodologia tem aspectos positivos, mas sua aplicação leva tempo e tem reflexos em toda cadeia de suprimentos.
Chromosomal loss of 3q26.3‐3q26.32, involving a partial neuroligin 1 deletion, identified by genomic microarray in a child with microcephaly, seizure disorder, and severe intellectual disability
Authors: Millson Alison , LaGrave Danielle , Willis Mary J.H. , Rowe Leslie R. , Lyon Elaine , South Sarah T.
Published: November 2011

Neuroligin 1 (NLGN1) is one of five members of the neuroligin gene family and may represent a candidate gene for neurological disorders, as members of this family are involved in formation and remodeling of central nervous system synapses. NLGN1 is expressed predominantly in the central nervous system, where it dimerizes and then binds with β‐neurexin to form a functional synapse. Mutations in neurexin 1 (NRXN1) as well as two other members of the neuroligin family, NLGN3 and NLGN4, have been associated with autism and mutations in NLGN4 have also been associated with intellectual disability, seizures, and EEG abnormalities. Genomic microarray is recommended for the detection of chromosomal gains or losses in patients with intellectual disability and multiple congenital anomalies. Results of uncertain significance are not uncommon. Parental studies can provide additional information by demonstrating that the imbalance is either de novo or inherited, and therefore is more or less likely to be causative of the clinical phenotype. However, the possibility that even inherited deletions and duplications may play a role in the phenotype of the proband cannot be excluded as many copy number variants associated with neurodevelopmental conditions show incomplete penetrance and may be inherited from an unaffected parent. Here, we report on a patient with a 2.2 Mb deletion at 3q26.3‐3q26.32—encompassing the terminal end of NLGN1 and the entire NAALADL2 gene—detected by genomic microarray, and confirmed by FISH and real‐time quantitative PCR. The same size deletion was subsequently found in her healthy, asymptomatic, adult mother. © 2011 Wiley Periodicals, Inc.
Microtia: Epidemiology and genetics
Authors: Luquetti Daniela V. , Heike Carrie L. , Hing Anne V. , Cunningham Michael L. , Cox Timothy C.
Published: November 2011

Microtia is a congenital anomaly of the ear that ranges in severity from mild structural abnormalities to complete absence of the ear, and can occur as an isolated birth defect or as part of a spectrum of anomalies or a syndrome. Microtia is often associated with hearing loss and patients typically require treatment for hearing impairment and surgical ear reconstruction. The reported prevalence varies among regions, from 0.83 to 17.4 per 10,000 births, and the prevalence is considered to be higher in Hispanics, Asians, Native Americans, and Andeans. The etiology of microtia and the cause of this wide variability in prevalence are poorly understood. Strong evidence supports the role of environmental and genetic causes for microtia. Although some studies have identified candidate genetic variants for microtia, no causal genetic mutation has been confirmed. The application of novel strategies in developmental biology and genetics has facilitated elucidation of mechanisms controlling craniofacial development. In this paper we review current knowledge of the epidemiology and genetics of microtia, including potential candidate genes supported by evidence from human syndromes and animal models. We also discuss the possible etiopathogenesis in light of the hypotheses formulated to date: Neural crest cells disturbance, vascular disruption, and altitude. © 2011 Wiley Periodicals, Inc.
Characteristics of the photochemical prevulcanization in a falling film photoreactor
Authors: Schlögl Sandra , Temel Armin , Schaller Raimund , Holzner Armin , Kern Wolfgang
Published: November 2011

The photochemical prevulcanization of natural rubber (NR) latex via the thiol‐ene reaction is a new approach aiming at the replacement of noxious processing agents used in conventional sulfur vulcanization processes (e.g., accelerators) together with cost saving options. The crosslinking reaction involves the excitation of a selected photoinitiator with ultraviolet (UV) light which is followed by the formation of thioether links due to the thiol‐ene addition reaction. The photochemical process is carried out in a falling film photoreactor which provides not only a continuous prevulcanization process but also exhibits a technology which is already commercially well established. The main advantage of the falling film process lies in the short prevulcanization time and the mild reaction temperature. Following the idea of the manufacture of low‐allergenic surgical gloves made from NR latex without compromising on the glove quality by means of physical performance, crucial process parameters of the falling film process have been determined and characterized in this study. Surgical gloves were made from the photocured NR latex which was prevulcanized using selected process conditions. The physical properties including tensile strength, elongation, modulus, and crosslink density were examined together with the aging stability and the stability against high‐energy radiation (sterilization with gamma rays). It was found that the UV light intensity, the number of illumination cycles, the choice of photoinitiator, and the thiol crosslinker play an important part in the glove quality. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
An improved sample preparation method for monomer conversion measurement using headspace gas chromatography in emulsion polymerization research
Authors: Zhong Jin‐Feng , Chai Xin‐Sheng , Fu Shi‐Yu , Qin Xiao‐Li
Published: November 2011

This article reports an improved headspace gas chromatographic (HS‐GC) technique for the determination of monomers in polymer latex. The method is based on a HS‐GC technique reported previously (Chai et al., J Appl Polym Sci 2006, 99, 392) but includes a major modification in the method of sample preparation. By using a weight‐based sampling method, coupled with initial dissolution in dimethyl sulfoxide (DMSO), followed by water dilution, the uncertainty in the sample preparation associated with previous method can be significantly reduced. The improved method is reliable, practical, and suitable for use in the kinetic study during emulsion polymerization. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
State Variable Approach for the Structural Analysis of Hormonal Controlled Long Term Blood Pressure Regulatory System
Authors: Shahin M. , Maka S.
Published: November 2011

Long term arterial blood pressure regulation involves complex interactions of the cardiovascular system, kidney and other organs. In hypertension related diseases, the control pathways are impaired and parameters for its quantification might be of prognostic importance. In this paper, we introduce methods based on the state variable approach for the enhanced analysis of complex interactions. To assess the dynamics of arterial blood pressure regulation, the linearized state model has been employed. This paper presents a seventh order nonlinear mathematical model of the long term arterial blood pressure regulation incorporating many of the nervous control mechanisms and hormonal activities. Subsequently, the structural properties, as well as the transient and steady state properties, are assessed using the eigen value concept. The comparison of model response with those of the nonlinear model shows close matching. In conclusion, the analysis of the linearised model provides insights into complex, nonlinear physiological interactions and furthermore reveals physiological cardiovascular control about the equilibrium point.
On the Exponential Stability of Moving Horizon Observer for Globally N‐Detectable Nonlinear Systems
Authors: Sui Dan , Johansen Tor Arne
Published: November 2011

A moving horizon observer is analyzed for nonlinear discrete‐time systems. Exponential stability relies on a global detectability assumption that utilizes the concept of incremental input‐to‐state‐stability.
Combinatorial insulin secretion dynamics of recombinant hepatic and enteroendocrine cells
Authors: Durvasula Kiranmai , Thulé Peter M. , Sambanis Athanassios
Published: November 2011

One of the most promising cell‐based therapies for combating insulin‐dependent diabetes entails the use of genetically engineered non‐β cells that secrete insulin in response to physiologic stimuli. A normal pancreatic β cell secretes insulin in a biphasic manner in response to glucose. The first phase is characterized by a transient stimulation of insulin to rapidly lower the blood glucose levels, which is followed by a second phase of insulin secretion to sustain the lowered blood glucose levels over a longer period of time. Previous studies have demonstrated hepatic and enteroendocrine cells to be appropriate hosts for recombinant insulin expression. Due to different insulin secretion kinetics from these cells, we hypothesized that a combination of the two cell types would mimic the biphasic insulin secretion of normal β cells with higher fidelity than either cell type alone. In this study, insulin secretion experiments were conducted with two hepatic cell lines (HepG2 and H4IIE) transduced with 1 of 3 adenoviruses expressing the insulin transgene and with a stably transfected recombinant intestinal cell line (GLUTag‐INS). Insulin secretion was stimulated by exposing the cells to glucose only (hepatic cells), meat hydrolysate only (GLUTag‐INS), or to a cocktail of the two secretagogues. It was found experimentally that the recombinant hepatic cells secreted insulin in a more sustained manner, whereas the recombinant intestinal cell line exhibited rapid insulin secretion kinetics upon stimulation. The insulin secretion profiles were computationally combined at different cell ratios to arrive at the combinatorial kinetics. Results indicate that combinations of these two cell types allow for tuning the first and second phase of insulin secretion better than either cell type alone. This work provides the basic framework in understanding the secretion kinetics of the combined system and advances it towards preclinical studies. Biotechnol. Bioeng. 2012; 109:1074–1082. © 2011 Wiley Periodicals, Inc.
Application of hollow fiber‐supported liquid‐phase microextraction coupled with HPLC for the determination of guaifenesin enantiomer–protein binding
Authors: Hatami Mehdi , Farhadi Khalil
Published: November 2011

A hollow fiber liquid‐phase microextraction technique coupled with high‐performance liquid chromatography with fluorescence detection was employed for determination and evaluation of the binding characteristics of drugs to bovine serum albumin (BSA). Enantiomers of guaifenesin (an expectorant drug) were investigated as a model system. After optimization of some influencing parameters on microextraction, the proposed method was used for calculation of the target drug distribution coefficient between n‐octanol and the buffer solution as well as study of drug–BSA binding in physiological conditions. The developed method shows a new, improved and simple procedure for determination of free drug concentration in biological fluids and the extent of drug–protein binding. Copyright © 2011 John Wiley & Sons, Ltd.
Infusion of mesenchymal stem cells overexpressing GDNF ameliorates renal function in nephrotoxic serum nephritis
Authors: Huang Zheng‐Yu , Hong Liang‐Qing , Na Ning , Luo Yun , Miao Bin , Chen Jun
Published: November 2011

Nephrotoxic serum nephritis (NSN) is a well‐established animal model of glomerulonephritis, a frequent clinical condition with a high mortality rate owing to the ineffectiveness of current therapies. Mesenchymal stem cells (MSCs) are adult stem cells with potential as novel therapies in regenerative medicine owing to the absence of allogenic rejection. Glial cell‐derived neurotrophic factor (GDNF) acts as a morphogen in kidney development. The therapeutic effectiveness of bone marrow MSCs overexpressing GDNF (GDNF‐MSCs) was evaluated in an NSN rat model. An adenoviral vector was used to transduce MSCs with GDNF and a green fluorescent protein reporter gene. Then, GDNF‐MSCs were injected into NSN rats via the renal artery. The influence of GDNF on renal injury was assessed. The location of GDNF‐MSCs in kidneys was detected using fluorescence microscopy, cells were counted, and kidney function was measured. Infusion of GNDF‐MSCs enhanced the recovery of renal function in NSN rats. MSCs were detected in the kidney cortex after injection. Compared with control MSCs, GDNF‐MSCs led to significantly better renal function and injury recovery in NSN rats. GDNF has a positive effect on MSC differentiation in renal tissue. Owing to their highly renoprotective capacity, GDNF‐MSCs represent a possible novel cell‐based paradigm for treatment of glomerulonephritis. Copyright © 2011 John Wiley & Sons, Ltd.
Transcatheter aortic valve implantation with a self‐expanding nitinol bioprosthesis
Authors: Saia Francesco , Lemos Pedro A. , Bordoni Barbara , Cervi Elena , Boriani Giuseppe , Ciuca Cristina , Taglieri Nevio , Mariani Jose , Filho Roberto Kalil , Marzocchi Antonio
Published: November 2011

Objective: To ascertain incidence and predictors of new permanent pacemaker (PPM) following transcatheter aortic valve implantation (TAVI) with the self‐expanding aortic bioprosthesis. Background: TAVI with the Medtronic Corevalve (MCV) Revalving System (Medtronic, Minneapolis, MN) has been associated with important post‐procedural conduction abnormalities and frequent need for PPM. Methods: Overall, 73 consecutive patients with severe symptomatic AS underwent TAVI with the MCV at two institutions; 10 patients with previous pacemaker and 3 patients with previous aortic valve replacement were excluded for this analysis. Clinical, echocardiographic, and procedural data were collected prospectively in a dedicated database. A standard 12‐lead ECG was recorded in all patients at baseline, after the procedure and predischarge. Decision to implant PPM was taken according to current guidelines. Logistic multivariable modeling was applied to identify independent predictors of PPM at discharge. Results: Patients exhibited high‐risk features as evidenced by advanced age (mean = 82.1 ± 6.2 years) and high surgical scores (logistic EuroSCORE 23.0 ± 12.8%, STS score 9.4 ± 6.9%). The incidence of new PPM was 28.3%. Interventricular septum thickness and logistic Euroscore were the baseline independent predictors of PPM. When procedural variables were included, the independent predictors of PPM were interventricular septum thickness (OR 0.52; 95% CI 0.32–0.85) and the distance between noncoronary cusp and the distal edge of the prosthesis (OR 1.37; 95% CI 1.03–1.83). Conclusions: Conduction abnormalities are frequently observed after TAVI with self‐expandable bioprosthesis and definitive pacing is required in about a third of the patients, with a clear association with depth of implant and small interventricular septum thickness. © 2011 Wiley Periodicals, Inc.
Organogel–Hydrogel Transformation by Simple Removal or Inclusion of N‐Boc‐Protection
Authors: Kar Tanmoy , Mandal Subhra Kanti , Das Prasanta Kumar
Published: November 2011

Development of organo‐ and hydrogelators is on the rise because of their extensive applications, from advanced materials to biomedicine. However, designing both types of gelator from a common structural scaffold is challenging, and becomes more significant if transformation between them can be achieved by a simple method. The present work reports the design and synthesis of both organo‐ and hydrogelators from amino acid/peptide‐based amphiphilic precursors with a naphthyl group at the N terminus and a primary amine‐containing hydrophilic ethyleneoxy unit at the C terminus. In alkaline medium, tert‐butyloxycarbonyl (Boc) protection at the primary amine of the amphiphiles resulted in efficient organogelators (minimum‐gelation concentration (MGC)=0.075–1.5 % w/v). Interestingly, removal of the Boc protection from the ethyleneoxy unit, under acidic conditions, yielded amphiphiles capable of gelating water (MGC=0.9–3.0 % w/v). Simple protection and deprotection chemistry was used to achieve transformation between the organogel and hydrogel by alteration of the pH. Combinations of different aliphatic and aromatic amino acids were investigated to discover their cumulative effect on the gelation properties. Field‐emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) were employed to investigate the supramolecular morphology of the thermoreversible gels. Spectroscopic investigations (FTIR, photoluminescence, XRD) revealed that noncovalent interactions, such as hydrogen bonding, π–π stacking, and van der Waals interactions play a decisive role in self‐assembled gelation.
Exploring photochemistry of 2‐(phenylazo)pyridine dye by using TDDFT/DFT methods
Authors: Tongying Pornthip , Yoopensuk Suthirat , Leesakul Nararak , Tantirungrotechai Yuthana
Published: November 2011

The non‐emissive behaviour of 2‐(phenylazo)pyridine, azpy, observed in the fluorescence experiment was explained by investigating its photoisomerisation mechanism. By using the Density Functional Theory and Time‐dependent Density Functional Theory (DFT/TDDFT) methods, the two‐dimensional potential energy surfaces in the ground state, and the first and second excited states which are relevant to the trans‐to‐cis isomerisation were constructed. The pathways related to the inversion, rotation and their concerted motion of the phenyl and pyridyl groups around NN bond were considered. The energy profiles depend not only on the type of pathways but also on the moving group. The concerted‐inversion pathways show the possibility of S1/S2 and S0/S1 conical intersections. The relaxation through such intersections should increase the non‐radiative transition rate to the extent that the compound does not emit fluorescence. © 2011 Canadian Society for Chemical Engineering
Evolutionary reputation model for node selfishness resistance in opportunistic networks
Authors: Zhang Sihai , Qiu Hongyang , Liu Yuan , Zhou Wuyang
Published: November 2011

Selfish behavior of nodes in opportunistic networks impact greatly on the network performance. Therefore, an effective mechanism should be proposed to resist such misbehavior and to stimulate the nodes willing to relay packets for other nodes toward their destinations. On the basis of the evolutionary reputation model proposed, this paper investigates the network performance, including message delivery ratio, average delivery delay, and average intermittent hops, under the influence of reputation degree and selfish degree. In addition, the reputation evolution process is described, which helps to understand the interaction among network nodes. Simulation results show that the opportunistic network adopting the model proposed can resist partially the node selfishness and maintain acceptable network performance. Copyright © 2011 John Wiley & Sons, Ltd.
A study of parallel tuner with voltage‐dependent capacitance
Authors: Eskandarian Abdollah
Published: November 2011

A study of varactor tuned LC circuits is presented. Nonlinear time domain circuit differential equation is rewritten in terms of phase plane variables, which can then be solved in closed form. General expressions are derived, which are applicable to any capacitance–voltage relationship. Two types of circuit structures, namely single‐ended and balanced, with MOS diodes as the variable capacitance elements, are specifically considered. The nature of the voltage waveforms across the two circuits is determined by phase plane plots. Variation of voltage with time is calculated numerically. It is shown that the voltage waveform for the single‐ended circuit is asymmetric, with higher harmonics present. Furthermore, the fundamental resonant frequency is dependent on amplitude of oscillation and could decrease to 94% of its small signal value for large voltage swings. Near 34% control over frequency is calculated, for a bias voltage range of 8 to 1. On the other hand, the balanced structure results in symmetric voltage waveform, with negligible harmonic content. Dependence of frequency on amplitude is weak, only decreasing to 98% of its small signal value, for the largest swings. The tuning range is marginally improved by the balanced structure. The results are compared with those obtained from Fourier‐based calculations and experimental data in literature, and good agreement is obtained. Copyright © 2011 John Wiley & Sons, Ltd.
Role of Hedgehog signalling at the transition from double‐positive to single‐positive thymocyte
Authors: Furmanski Anna L. , Saldana Jose Ignacio , Rowbotham Nicola J. , Ross Susan E. , Crompton Tessa
Published: November 2011

In the thymus, developing T cells receive signals that determine lineage choice, specificity, MHC restriction and tolerance to self‐antigen. One way in which thymocytes receive instruction is by secretion of Sonic hedgehog (Shh) from thymic epithelial cells. We have previously shown that Hedgehog (Hh) signalling in the thymus decreases the CD4:CD8 single‐positive (SP) thymocyte ratio. Here, we present data indicating that double‐positive (DP) thymocytes are Hh‐responsive and that thymocyte‐intrinsic Hh signalling plays a role in modulating the production of CD4+ (SP4), CD8+ (SP8) and unconventional T‐cell subsets. Repression of physiological Hh signalling in thymocytes altered the proportions of DP and SP4 cells. Thymocyte‐intrinsic Hh‐dependent transcription also attenuated both the production of mature SP4 and SP8 cells, and the establishment of peripheral T‐cell compartments in TCR‐transgenic mice. Additionally, stimulation or withdrawal of Hh signals in the WT foetal thymus impaired or enhanced upregulation of the CD4 lineage‐specific transcription factor Gata3 respectively. These data together suggest that Hh signalling may play a role in influencing the later stages of thymocyte development.
Half of the T‐cell repertoire combinatorial diversity is genetically determined in humans and humanized mice
Authors: Pham Hang‐Phuong , Manuel Manuarii , Petit Nicolas , Klatzmann David , Cohen‐Kaminsky Sylvia , Six Adrien , Marodon Gilles
Published: November 2011

In humanized mice, the T‐cell repertoire is derived from genetically identical human progenitors in distinct animals. Thus, careful comparison of the T‐cell repertoires of humanized mice with those of humans may reveal the contribution of genetic determinism on T‐cell repertoire formation. Here, we performed a comprehensive assessment of the distribution of V‐J combinations of the human β chain of the T‐cell receptor (hTRBV) in NOD.SCID.γc−/− (NSG) humanized mice. We observed that numerous V‐J combinations were equally distributed in the thymus and in the periphery of humanized mice compared with human references. A global analysis of the data, comparing repertoire perturbation indices in humanized NSG mice and unrelated human PBMCs, reveals that 50% of the hTRBV families significantly overlapped. Using multivariate ranking and bootstrap analyses, we found that 18% of all possible V‐J combinations contributed close to 50% of the expressed diversity, with significant over‐representation of BV5‐J1.1+1.2 and BV6‐J1.1+1.2 rearrangements. Finally, comparison of CD3− and CD3+ thymocyte repertoires indicated that the observed V‐J combination overlap was already present before TCR‐MHC selection in the thymus. Altogether, our results show that half of the T‐cell repertoire combinatorial diversity in humans is genetically determined.
Dyes That Bear Thiazolylazo Groups as Chromogenic Chemosensors for Metal Cations
Authors: Ábalos Tatiana , Moragues María , Royo Santiago , Jiménez Diego , Martínez‐Máñez Ramón , Soto Juan , Sancenón Félix , Gil Salvador , Cano Joan
Published: November 2011

A family of dyes (L1–L6) that contain a thiazolylazo group as signalling subunit and several macrocyclic cavities with different ring sizes and type and number of heteroatoms as binding sites has been synthesized and characterized. Solutions of L1–L6 in acetonitrile show broad and structureless absorption bands in the 554–577 nm range with typicalmolar absorption coefficients that range from 20000 to 32000 M–1 cm–1. A detailed protonation study was carried out with solutions of L1, L2 and L5 in acetonitrile. Addition of one equivalent of protons to L1 and L2 resulted in the development of a new band at 425 and 370 nm, respectively, which was ascribed to protonation in the aniline nitrogen. In contrast, protonation of L5 resulted in a bathochromic shift of 25 nm of the absorption band that was conceivable with protonation of one of the nitrogen atoms of the azo moiety. These results were in agreement with 1H NMR spectroscopic data. Theoretical studies on the model ligand L1 and on different possible protonation species were also performed by using density functional theory (DFT) quantum mechanical calculations. Colour modulations in solutions of L1–L6 in acetonitrile in the presence of the metal cations Fe3+, Ni2+, Zn2+, Cd2+, Pb2+ and Hg2+ have been studied. A selective chromogenic response of L4 in the presence of Pb2+ and L5 in the presence of Hg2+ was observed. To get a better insight into the chromophoric nature in the presence of metal cations, the interaction of Hg2+ with the model compound L1 in two different coordination modes was studied theoretically by using density functional theory (DFT) quantum mechanical calculations.
In vivo biocompatibility and in vitro characterization of poly‐lactide‐co‐glycolide structures containing levetiracetam, for the treatment of epilepsy
Authors: Halliday Amy J. , Campbell Toni E. , Razal Joselito M. , McLean Karen J. , Nelson Timothy S. , Cook Mark J. , Wallace Gordon G.
Published: November 2011

Epilepsy is a chronic neurological disorder characterized by recurrent seizures, and is highly resistant to medication with up to 40% of patients continuing to experience seizures whilst taking oral antiepileptic drugs. Recent research suggests that this may be due to abnormalities in the blood–brain barrier, which prevent the passage of therapeutic substances into the brain. We sought to develop a drug delivery material that could be implanted within the brain at the origin of the seizures to release antiepileptic drugs locally and avoid the blood brain barrier. We produced poly‐lactide‐co‐glycolide drop‐cast films and wet‐spun fibers loaded with the novel antiepileptic drug Levetiracetam, and investigated their morphology, in vitro drug release characteristics, and brain biocompatibility in adult rats. The best performing structures released Levetiracetam constantly for at least 5 months in vitro, and were found to be highly brain biocompatible following month‐long implantations in the motor cortex of adult rats. These results demonstrate the potential of polymer‐based drug delivery devices in the treatment of epilepsy and warrant their investigation in animal models of focal epilepsy. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Injectable polyurethane composite scaffolds delay wound contraction and support cellular infiltration and remodeling in rat excisional wounds
Authors: Adolph Elizabeth J. , Hafeman Andrea E. , Davidson Jeffrey M. , Nanney Lillian B. , Guelcher Scott A.
Published: November 2011

Injectable scaffolds present compelling opportunities for wound repair and regeneration because of their ability to fill irregularly shaped defects and deliver biologics such as growth factors. In this study, we investigated the properties of injectable polyurethane (PUR) biocomposite scaffolds and their application in cutaneous wound repair using a rat excisional model. The scaffolds have a minimal reaction exotherm and clinically relevant working and setting times. Moreover, the biocomposites have mechanical and thermal properties consistent with rubbery elastomers. In the rat excisional wound model, injection of settable biocomposite scaffolds stented the wounds at early time points, resulting in a regenerative rather than a scarring phenotype at later time points. Measurements of wound length and thickness revealed that the treated wounds were less contracted at day 7 compared to blank wounds. Analysis of cell proliferation and apoptosis showed that the scaffolds were biocompatible and supported tissue ingrowth. Myofibroblast formation and collagen fiber organization provided evidence that the scaffolds have a positive effect on extracellular matrix remodeling by disrupting the formation of an aligned matrix under elevated tension. In summary, we have developed an injectable biodegradable PUR biocomposite scaffold that enhances cutaneous wound healing in a rat model. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Deproteinization technique stabilizes the adhesion of the fiberglass post relined with resin composite to root canal
Authors: Cecchin Doglas , Almeida José F. A. , Gomes Brenda P. F. A. , Zaia Alexandre A. , Ferraz Caio C. R.
Published: November 2011

To evaluate the effects of pretreatment of root dentin by 5.25% sodium hypochlorite (NaOCl) alone, associated with 2% chlorhexidine in gel base (CHX) and/or ethanol (EtOH), and the air‐drying technique (Air) on the bond strength and adhesive durability of fiberglass post relined with resin composite to root dentin. A total of 100 bovine incisor roots were divided into 10 groups: G1 (control), irrigation with physiologic solution; G2, Air; G3, NaOCl; G4, NaOCl + Air; G5, NaOCl + EtOH; G6, NaOCl + EtOH + Air; G7, NaOCl + CHX; G8, NaOCl + CHX + Air; G9, NaOCl + CHX + EtOH; G10, NaOCl + CHX + EtOH + Air. Fiberglass post relined with resin composite was cemented and each group was randomly divided into two subgroups: 24 h of water storage and 12 months of water storage. The push‐out test was performed and bond strength values were analyzed by ANOVA and Tukey's test. The use of NaOCl alone or associated with CHX had the highest values of bond strength with or without Air in the immediate and stored groups, being statistically similar to the immediate control group (p > 0.05). The groups using EtOH or Air alone had lower bond strength in the immediate and stored groups (p < 0.05). A significant decrease with the time of the bond strength in the control group was observed after 12 months of storage (p > 0.05). The use of NaOCl or NaOCl associated with CHX preserved the bond strength immediate and for 12 months. The air‐drying technique and the other associations decreased the immediate bond strength values. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 577–583, 2012.
Strontium‐loaded mineral bone cements as sustained release systems: Compositions, release properties, and effects on human osteoprogenitor cells
Authors: Tadier Solène , Bareille Reine , Siadous Robin , Marsan Olivier , Charvillat Cédric , Cazalbou Sophie , Amédée Joelle , Rey Christian , Combes Christèle
Published: November 2011

This study aims to evaluate in vitro the release properties and biological behavior of original compositions of strontium (Sr)‐loaded bone mineral cements. Strontium was introduced into vaterite CaCO3‐dicalcium phosphate dihydrate cement via two routes: as SrCO3 in the solid phase (SrS cements), and as SrCl2 dissolved in the liquid phase (SrL cements), leading to different cement compositions after setting. Complementary analytical techniques implemented to thoroughly investigate the release/dissolution mechanism of Sr‐loaded cements at pH 7.4 and 37°C during 3 weeks revealed a sustained release of Sr and a centripetal dissolution of the more soluble phase (vaterite) limited by a diffusion process. In all cases, the initial burst of the Ca and Sr release (highest for the SrL cements) that occurred over 48 h did not have a significant effect on the expression of bone markers (alkaline phosphatase, osteocalcin), the levels of which remained overexpressed after 15 days of culture with human osteoprogenitor (HOP) cells. At the same time, proliferation of HOP cells was significantly higher on SrS cements. Interestingly, this study shows that we can optimize the sustained release of Sr2+, the cement biodegradation and biological activity by controlling the route of introduction of strontium in the cement paste. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 378–390, 2012.