bluuebunny/crossref_metadata_2025_split huggingface dataset:
An optimized nested polymerase chain reaction (PCR) approach allows detection and characterization of human immunodeficiency virus type 1 (HIV‐1) env and gag genes from clinical samples
Authors: Locateli Dayse , Stoco Patricia H. , Zanetti Carlos R. , Pinto Aguinaldo R. , Grisard Edmundo C. 
Published: March 2008

AbstractThe needs for development and/or improvement of molecular approaches for microorganism detection and characterization such as polymerase chain reaction (PCR) are of high interest due their sensitivity and specificity when compared to traditional microbiological techniques. Considering the worldwide importance of human immunodeficiency virus type 1 (HIV‐1) infection, it is essential that such approaches consider the genetic variability of the virus, the heterogeneous nature of the clinical samples, the existence of contaminants and inhibitors, and the consequent needs for standardization in order to guarantee the reproducibility of the methods. In this work we describe a nested PCR assay targeting HIV‐1 virus gag and env genes, allowing specific and sensitive diagnosis and further direct characterization of clinical samples. The method described herein was tested on clinical samples and allowed the detection of HIV‐1 presence in all samples tested for the gag gene and 90.9% for the env gene, revealing sensitivities of 1 fg and 100 fg, respectively. Also, no cross‐reactions were observed with DNA from infected and noninfected patients and the method allowed detection of the env and gag genes on an excess of 108 and 104 of human deoxyribonucleic acid (DNA), respectively. Furthermore, it was possible to direct sequence all amplified products, which allowed the sub typing of the virus in clinical samples. J. Clin. Lab. Anal. 22:106–113, 2008. © 2008 Wiley‐Liss, Inc.
Preliminary clinical measurement of the expression of TNF‐related apoptosis inducing ligand in patients with ankylosing spondylitis
Authors: Zai‐Xing Yang , Yan Liang , Hao Wang , Ye Zhu , Chang Li , Ren‐Qian Zhong 
Published: March 2008

AbstractIt has recently been reported that tumor necrosis factor (TNF)‐related apoptosis inducing ligand (TRAIL) plays various roles in such autoimmune diseases as diabetes, multiple sclerosis (MS), and systemic lupus erythematosus (SLE). However, it has still remained unclear whether there is a close relationship between TRAIL and ankylosing spondylitis (AS). In this study, we investigated the association between the expression of TRAIL and AS. The specific messenger ribonucleic acid (mRNA) levels of TRAIL in peripheral blood mononuclear cells (PBMCs), serum sTRAIL, and TNF‐α concentrations from 60 AS patients, 20 rheumatoid arthritis (RA) patients, and 30 healthy controls were determined by real‐time fluorescent quantitative polymerase chain reaction (PCR) and enzyme‐linked immunosorbent assay (ELISA). The results indicated that the expression levels of TRAIL mRNA, and serum sTRAIL were significantly elevated in AS patients, compared with RA patients and healthy controls, and there was a close association between TRAIL mRNA and sTRAIL levels. However, there was no significant difference between human leukocyte antigen (HLA)‐B27‐positive and ‐negative AS patients. In HLA‐B27‐positive patients, TRAIL mRNA and sTRAIL closely correlated with serum TNF‐α and C‐reactive protein (CRP), but did not correlate in HLA‐B27‐negative patients. In conclusion, upregulated expression of TRAIL might be somewhat specific for evaluation of AS. J. Clin. Lab. Anal. 22:138–145, 2008. © 2008 Wiley‐Liss, Inc.
Installing the communities that care prevention system: implementation progress and fidelity in a randomized controlled trial
Authors: Quinby Rose K. , Hanson Koren , Brooke‐Weiss Blair , Arthur Michael W. , Hawkins J. David , Fagan Abigail A. 
Published: March 2008

AbstractThis article describes the degree to which high fidelity implementation of the Communities That Care (CTC) prevention operating system was reached during the first 18 months of intervention in 12 communities in the Community Youth Development Study, a 5‐year group randomized controlled trial designed to test the efficacy of the CTC system. CTC installation in these communities included the delivery of six CTC trainings from certified CTC trainers at each site, the active involvement of locally selected and community‐based CTC community coordinators, ongoing monitoring of progress using the CTC milestones and benchmarks, and proactive technical assistance and coaching. CTC implementation fidelity ratings averaged across three groups of raters show that between 89% and 100% of the CTC milestones in the first four phases of CTC implementation were “completely met” or “majority met” in the 12 intervention communities, indicating that the first four phases of the CTC system have been well implemented in the communities in this trial. © 2008 Wiley Periodicals, Inc.
Children speak about neighborhoods: using mixed methods to measure the construct neighborhood
Authors: Nicotera Nicole 
Published: March 2008

AbstractThis study contributes to the knowledge base of community practice and research by examining the construct neighborhood from qualitative and quantitative perspectives. Mixed methodology was employed to explore the associations and discrepancies between a census measure of neighborhood based in social disorganization theory and a qualitative measure based on the voices of children (N=59). Qualitative results indicate nine dimensions of the construct neighborhood that are not found in census‐based measures of the construct. Mixed methods results demonstrate that children in both higher and lower socially disorganized neighborhoods express the presence of neighborhood resources and neighborly affiliations as well as negative neighborhood experiences. Expressions of fear, needs for safety, and qualities of unsavory characters distinguish the two types of neighborhoods. © 2008 Wiley Periodicals, Inc.
Determination of triptonide by cloud point extraction combined with MEKC
Authors: Wu Yi‐Wei , Jiang Yin‐Yan , Xiao Tang‐Xin , Zhang Hai‐Li 
Published: March 2008

AbstractA method has been developed for the determination of triptonide in the traditional Chinese herb Tripterygium wilfordii Hook F. by micellar electrokinetic capillary chromatography combined with cloud point extraction. The analyte was extracted at pH 3.0 by micelles of the nonionic surfactant polyoxyethylene 7,5‐octylphenyl ether (Triton X‐114). A 250‐μL aliquot from the extracted surfactant‐rich phase was diluted to 400 μL with ethanol to reduce its viscosity before separation by MEKC. Under optimum conditions, an enrichment factor of 25 is obtained and the determination limit of triptonide is found to be 3.15×10–7 mol/L. The proposed method has been successfully applied to the determination of triptonide in T. wilfordii tablet and spiked urine matrix, demonstrating the feasibility and reliability of the proposed method.
Utility of separation science in metabolomic studies
Authors: Issaq Haleem J. , Abbott Eric , Veenstra Timothy D. 
Published: March 2008

AbstractMetabolomics, or alternately metabonomics, an emerging field of biochemical research, is a complementary technique to genomics, transcriptomics, and proteomics. Direct quantitative measurements of metabolite expressions in urine, serum, plasma, and tissue are essential for the study of biological processes in normal and disease states. Since the number of metabolites in a biological sample is large separation science plays an important role in metabolomic research. This review describes the role of GC, HPLC, CE, and supercritical fluid chromatography in metabolomic research. The application of each technique is discussed and its advantages and limitations are discussed with selective illustrative examples.
Chemical Conjugation of Linear and Cyclic RGD Moieties to a Recombinant Elastin‐Mimetic Polypeptide ‐ A Versatile Approach towards Bioactive Protein Hydrogels
Authors: Kaufmann Doris , Fiedler Anne , Junger Andreas , Auernheimer Jörg , Kessler Horst , Weberskirch Ralf 
Published: March 2008

AbstractAn elastin‐mimetic polypeptide, (EMM)7, with the amino‐acid sequence GRDPSS [VPGVG VPGKG VPGVG VPGVG VPGEG VPGIG]7 was used for chemical conjugation of various integrin ligands (RGD peptides) to prepare bioactive hydrogels. The chemical approach involved (1) chemical protection of lysine residues with Fmoc or Boc groups, (2) chemical ligation of a protected linear or cyclic RGD ligand, with or without a hexanoic‐acid spacer to the glutamic acid residue, (3) deprotection of the lysine functionalities and the RGD moieties and (4) cross‐linking to form a bioactive hydrogel. 1H NMR spectroscopy was used to quantify the multiple steps in the reaction. The chemical protection was found to be between 65 and 93% for Fmoc and Boc, respectively. The ligands studied included linear RGD cell‐binding [HFGRGDSOH (1‐l‐RGD), HAhxFGRGDSOH (2‐AhxFGRGDS) and a cyclic H2N(CH2)6COHNcyclo(RGDfK) (HAhxc(RGDfK)) peptide also with a hexanoic‐acid spacer. Cell adhesion with mouse osteoblast cells was dependent on the ligand type, ligand density and the use of a spacer.magnified image
Open‐Pore Biodegradable Foams Prepared via Gas Foaming and Microparticulate Templating
Authors: Salerno Aurelio , Iannace Salvatore , Netti Paolo A. 
Published: March 2008

AbstractOpen‐pore biodegradable foams with controlled porous architectures were prepared by combining gas foaming and microparticulate templating. Microparticulate composites of poly(ε‐caprolactone) (PCL) and micrometric sodium chloride particles (NaCl), in concentrations ranging from 70/30 to 20/80 wt.‐% of PCL/NaCl were melt‐mixed and gas‐foamed using carbon dioxide as physical blowing agent. The effects of microparticle concentration, foaming temperature, and pressure drop rate on foam microstructure were surveyed and related to the viscoelastic properties of the polymer/microparticle composite melt. Results showed that foams with open‐pore networks can be obtained and that porosity, pore size, and interconnectivity may be finely modulated by optimizing the processing parameters. Furthermore, the ability to obtain a spatial gradient of porosity embossed within the three‐dimensional polymer structure was exploited by using a heterogeneous microparticle filling. Results indicated that by foaming composites with microparticle concentration gradients, it was also possible to control the porosity and pore‐size spatial distribution of the open‐pore PCL foams.magnified image
A Non‐Covalent Method to Functionalize Multi‐Walled Carbon Nanotubes Using Six‐Armed Star Poly(L‐lactic acid) with a Triphenylene Core
Authors: Yang Li‐Ping , Pan Cai‐Yuan 
Published: March 2008

AbstractWell‐defined six‐armed star poly(L‐lactic acid) (PLLA) with a triphenylene core has been prepared by ring‐opening polymerization of L‐lactide. As a result of strong π–π interactions between the triphenylene core and the multi‐walled carbon nanotubes (MWCNTs), the polymer was conveniently immobilized on the surface of the as‐received MWCNTs by a simple ultrasonic process while the intrinsic graphitic structure of the pristine MWCNTs is retained. The non‐covalent interaction between the carbon nanotubes and the polymer has been proven by the UV‐vis absorption spectra, the fluorescence spectra, the Raman spectra, and the X‐ray photoelectron spectra.magnified image
Elongational Rheology of Polymer/Clay Dispersions: Determination of Orientational Extent in Elongational Flow Processes
Authors: Stefanescu Eduard A. , Petrovan Simioan , Daly William H. , Negulescu Ioan I. 
Published: March 2008

AbstractThe purpose of the present contribution is to provide an efficient method that would help to quantify the orientational levels occurring in polymer/clay dispersions subjected to elongational flow. The extent of internal orientation developed in salt containing montmorillonite/poly(ethylene oxide) gels is investigated, combining shear and elongational rheology methods. Entropic changes indicate that the strength of the transient network present in each gel affects the orientational ability of clay particles and polymer chains. We found that an increased Hencky strain of the hyperbolic die leads to a higher variation of the calculated entropy of the material.magnified image
Novel Electrospun Nanofibers Composed of Polyelectrolyte Complexes
Authors: Penchev Hristo , Paneva Dilyana , Manolova Nevena , Rashkov Iliya 
Published: March 2008

AbstractA simple method to obtain novel nanofibers composed of polyelectrolyte complexes (PECs) has been proposed. It consists of the electrospinning of a mixed homogeneous solution of polyelectrolyte partners, and the formation of PEC during the electrospinning. This was achieved by careful choice of the composition of the spinning solutions. Chitosan was the polycationic partner, with either a weak polyacid [poly(acrylic acid), PAA] as a counterpart or a strong one [poly(2‐acrylamido‐2‐methylpropanesulfonic acid), PAMPS]. The fibrous mats were composed of nanofibers with mean diameters of ca. 100 nm. They retained their integrity over the pH range which is typical of the corresponding PEC.magnified image
Influence of surface residual stresses on gigacycle fatigue response of high chromium cold work tool steel
Authors: Sohar C. R. , Betzwar‐Kotas A. , Gierl C. , Weiss B. , Danninger H. 
Published: March 2008

AbstractThe effect of surface compressive residual stresses (RS) induced by surface grinding and polishing on the gigacycle fatigue behavior of medium‐carbon high‐chromium alloy cold work tool steel was evaluated. Two test series were performed: Specimens of series I revealed high compressive RS of about ‐800 MPa at the surface, resulting from grinding with fine emery paper, which treatment had definitely a beneficial influence on the fatigue endurance strength. The existence of surface RS was also revealed to be responsible for the location of the fatigue crack initiation. High compressive RS favored internal crack origins. In this case crack nucleation sites were primary carbide clusters in the interior of the specimen, forming so‐called fish‐eyes at the fracture surface. In contrast, specimens of test series II had only very low RS, which enabled crack initiation near/at the surface at primary carbides/clusters. Furthermore, it has been shown that the high initial RS are prone to partial relaxation through cyclic loading for which the mechanisms are currently unknown. In this case near‐surface induced failure was obtained. It was possible to confirm the experimentally obtained data by the use of the concept of local fatigue strength as function of effective RS. The relaxation of high initial RS was experimentally confirmed through RS measurements at runout specimens (1010 cycles without failure).
Erratum: MRI monitoring of focal cerebral ischemia in peroxisome proliferator‐activated receptor (PPAR)‐deficient mice
Authors: Pialat Jean‐Baptiste , Cho Tae‐Hee , Beuf Olivier , Joye Elisabeth , Moucharaffie Samir , Langlois Jean‐Baptiste , Nemoz Chantal , Janier Marc , Berthezene Yves , Nighoghossian Norbert , Desvergne Béatrice , Wiart Marlène 
Published: March 2008

AbstractNMR In Biomedicine: MRI monitoring of focal cerebral ischemia in peroxisome proliferator‐activated receptor (PPAR)‐deficient mice. Jean‐Baptiste Pialat, Tae‐Hee Chao, Olivier Beuf, Elisabeth Joye, Samir Moucharaffie, Jean‐Baptiste Langlois, Chantal Nemoz, Marc Janier, Yves Berthezene, Norbert Nighoghossian, Béatrice Desvergnre and Marlene Wiart. Published online April 24 2007, Issue 20:3, pp. 335–342; DOI: 10.1002/nbm.1157.Following publication it has been noted that an author's name was misspelt. As above, the author was spelt as “Samir Moucharaffie”. It should have been spelt as “Samir Moucharrafie”.
Efficiency of mixed hybrid finite element and multipoint flux approximation methods on quadrangular grids and highly anisotropic media
Authors: Younes Anis , Fontaine Vincent 
Published: March 2008

AbstractThe mixed hybrid finite element (MHFE) and the multipoint flux approximation (MPFA) methods are well suited for anisotropic heterogeneous domains since both are locally conservative and can handle general irregular grids. In this work, behaviours and performances of MHFE and MPFA methods are studied numerically for different heterogeneities and anisotropy factors on parallelograms and then on a more general quadrilateral grid.The superiority of MPFA in terms of accuracy and efficiency is clearly demonstrated for parallelogram grids. In the case of more general quadrilateral grids, MPFA becomes more central processing unit time consuming than MHFE. For high anisotropy factors, both methods give results with significant non‐physical oscillations. Copyright © 2008 John Wiley & Sons, Ltd.
Iterative solution schemes for quadratic DRM‐MD
Authors: Portapila M. , Power H. 
Published: March 2008

AbstractThe aim of this work is to find the most suitable iterative technique to solve linear systems of equations arising from the dual reciprocity method in multidomains (DRM‐MD). In this article, the surface variables of the governing equations and the shape functions of the boundary elements are quadratic functions, and for the dual reciprocity approximation the radial basis function (RBF) used is the augmented thin plate spline. A series of tests are carried out studying efficiency and accuracy of different Krylov iterative solvers, every one assessed with several preconditioners. The results are related to intrinsic properties of the linear systems such as condition numbers, sparsity patterns, singular values, and eigenvalues. Besides, the performance of the selected iterative solvers is studied in relation with the subdivision of the domain, taking into account total number of nodes of the whole mesh, number of internal nodes per subdomain, as well as different aspect ratios of the mesh grids. As a result, performances of different refining schemes are considered. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008
Mortar element methods for parabolic problems
Authors: Patel Ajit , Pani Amiya K. , Nataraj Neela 
Published: March 2008

AbstractIn this article a standard mortar finite element method and a mortar element method with Lagrange multiplier are used for spatial discretization of a class of parabolic initial‐boundary value problems. Optimal error estimates in L∞(L2) and L∞(H1)‐norms for semidiscrete methods for both the cases are established. The key feature that we have adopted here is to introduce a modified elliptic projection. In the standard mortar element method, a completely discrete scheme using backward Euler scheme is discussed and optimal error estimates are derived. The results of numerical experiments support the theoretical results obtained in this article. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2008
Null‐field approach for Laplace problems with circular boundaries using degenerate kernels
Authors: Chen Jeng‐Tzong , Shen Wen‐Cheng 
Published: March 2008

AbstractIn this article, a semi‐analytical method for solving the Laplace problems with circular boundaries using the null‐field integral equation is proposed. The main gain of using the degenerate kernels is to avoid calculating the principal values. To fully utilize the geometry of circular boundary, degenerate kernels for the fundamental solution and Fourier series for boundary densities are incorporated into the null‐field integral equation. An adaptive observer system is considered to fully employ the property of degenerate kernels in the polar coordinates. A linear algebraic system is obtained without boundary discretization. By matching the boundary condition, the unknown coefficients can be determined. The present method can be seen as one kind of semianalytical approaches since error only attributes to the truncated Fourier series. For the eccentric case, vector decomposition technique for the normal and tangential directions is carefully considered in implementing the hypersingular equation in mathematical essence although we transform it to summability to divergent series. The five advantages, well‐posed linear algebraic system, principal value free, elimination of boundary‐layer effect, exponential convergence, and mesh free, are achieved. Several examples involving infinite, half‐plane, and bounded domains with circular boundaries are given to demonstrate the validity of the proposed method. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Features of mechanism of free radical initiation in polymers under exposure to nitrogen oxides
Authors: Davydov E. Y. , Gaponova I. S. , Pokholok T. V. , Vorotnikov A. P. , Pariiskii G. B. , Zaikov G. E. 
Published: March 2008

AbstractThe mechanism of interactions of NO, NO2, NO3 as well as dimers of NO2 with functional groups of organic molecules and polymers is considered. It is shown that nitrogen oxides are active initiators of radical reactions as a result of which various molecular products of nitration and stable nitrogen‐containing radicals are formed. Features of the initiation mechanism determining the composition of molecular and radical products of conversions of the compounds on exposure to nitrogen oxides have been revealed. Copyright © 2008 John Wiley & Sons, Ltd.
Mechanical properties of injection molded long fiber polypropylene composites, Part 2: Impact and fracture toughness
Authors: Senthil Kumar K. , Bhatnagar Naresh , Ghosh Anup K. 
Published: March 2008

AbstractThis study describes the effect of fiber length and compatibilizer content on notched izod impact and fracture toughness properties. Long fiber polypropylene (LFPP) pellets of different sizes were prepared by extrusion process using a new radial impregnation die, and subsequently, pellets were injection molded as described in previous publication 1. The content of glass fiber reinforcement was maintained same for all compositions. Maleic‐anhydride grafted polypropylene (MA‐g‐PP) was chosen as a compatibilizer to increase the adhesion between glass fiber and PP matrix and its content was maintained at 2 wt%. Notched izod impact property was studied for LFPP composites prepared with and without compatibilizer for different pellet sizes. Failure mechanism due to sudden impact was analyzed with scanning electron micrographs and was correlated with impact property of LFPP composites. Fracture and failure behavior of injection molded LFPP composite were studied and relationship between fracture toughness and microstructure of LFPP composite was analyzed. The microstructure of the composites was characterized by the dimensionless reinforcing effectiveness parameter, which accounts for the influence of fiber layer structure, fiber alignment, fiber volume fraction, fiber length distribution, and aspect ratio. Matrix stress condition factor and energy absorption ratio were determined for LFPP composites prepared with and without compatibilizer. Failure mechanism of both the matrix and fiber, revealed with SEM images, were discussed. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers