bluuebunny/crossref_metadata_2025_split huggingface dataset:
Validation of hand‐held bioelectrical impedance analysis with magnetic resonance imaging for the assessment of body composition in overweight women
Authors: Varady Krista A. , Santosa Sylvia , Jones Peter J. H. 
Published: April 2007

AbstractMethods of assessing body composition suitable for use in clinical trials should be accurate, reliable, and easy to perform. One such technique routinely implemented is hand‐held bioelectrical impedance analysis (BIA). The validity of this method, however, in body composition assessment of overweight women is not known. The aim of this study was to validate the hand‐held BIA technique with magnetic resonance imaging (MRI) for the assessment of body composition in overweight women. Fat mass, percent fat mass, fat‐free mass, and percent fat‐free mass values estimated by hand‐held BIA were compared to those measured by MRI. Thirty‐one Caucasian women (50.1 ± 8.2 years, body mass index of 26.9 ± 3.1 kg/m2) participated in the study. BIA measurements were highly reproducible (technical error (TE) was 0.06 ± 0.07 kg for fat mass and 0.08 ± 0.11% for percent fat mass), but were significantly different (P < 0.0001) for each body composition parameter when compared to MRI. BIA underestimated fat mass by 2.3 ± 3.3 kg and percent fat mass by 5.6 ± 3.9%. Likewise, BIA overestimated fat free mass by 7.4 ± 2.7 kg and percent fat free mass by 5.6 ± 3.2%. No relationship between the bias and the mean of the two measurements was noted suggesting that bias is not related to measurement size. Although hand‐held BIA gives reproducible findings, the bias noted for all body composition parameters puts into question the validity of this regional impedance device for use in clinical trials in overweight women.Am. J. Hum. Biol. 19:429–433, 2007. © 2007 Wiley‐Liss, Inc.
Enzyme immunoassay for total immunoglobulin E in dried blood spots
Authors: Tanner Susan , Mcdade Thomas W. 
Published: April 2007

AbstractElevated circulating levels of total immunoglobulin E (IgE) are associated with both allergic disease and repeated macro‐parasitic infections. Population‐based research on IgE has been limited by the logistical constraints associated with obtaining and processing venipuncture blood samples. In this short report, we present an enzyme immunoassay protocol for quantifying circulating total IgE levels in capillary whole blood, collected from a finger prick and dried on filter paper. The assay demonstrated acceptable levels of accuracy, precision, and reliability. IgE remained stable at room temperature for only 2–4 days and degraded rapidly at higher temperatures suggesting that samples should be refrigerated or frozen within 1–2 days of collection. It is hoped that the relative ease of blood spot collection will expand opportunities for population‐based research on IgE.Am. J. Hum. Biol. 19:440–442, 2007. © 2007 Wiley‐Liss, Inc.
Association analysis of COMT polymorphisms and schizophrenia in a Chinese Han population: A case‐control study
Authors: Yu Rui , Zhang Xian‐Ning , Huang Xiao‐Xiao , Ding Shi‐Ping , Li Ji‐Cheng 
Published: April 2007

AbstractSchizophrenia is a common disease with complex mode of inheritance; great efforts have been made to identify the susceptible genes. Catechol‐O‐methyltransferase (COMT) gene has long been considered as a candidate gene mainly because of two reasons: First, it encodes a key dopamine catabolic enzyme. Second, it maps to the velocardiofacial syndrome (VCFS) region of chromosome 22q11, which is associated with schizophrenia predisposition. Numerous case‐control and family‐based studies have been conducted, majority of them focused on a functional Val/Met polymorphism (rs4680). Unfortunately, these studies have produced conflicting results. In a previous report, Shifman et al. found a three‐marker haplotype (rs737865–rs4680–rs165599) that showed significant association with schizophrenia. In this study, we try to replicate their findings in Chinese Han population and failed to find any associations. © 2007 Wiley‐Liss, Inc.
Association of the neuropilin‐2 (NRP2) gene polymorphisms with autism in Chinese Han population
Authors: Wu Suping , Yue Weihua , Jia Meixiang , Ruan Yan , Lu Tianlan , Gong Xiaohong , Shuang Mei , Liu Jing , Yang Xiaoling , Zhang Dai 
Published: April 2007

AbstractAutism is a pervasive neurodevelopmental disorder, with a significant role of genetic factors in its development. The neuropilin‐2 (NRP2) gene is localized to 2q34, an autism susceptibility locus. NRP2 has been demonstrated to both guide axons and to control neuronal migration in the central nervous system. It has been reported that NRP2 may be required in vivo for sorting migrating cortical and striatal interneurons to their correct destination. We examine the association between the NRP2 gene and autism using a cohort of 169 Chinese Han family trios. Four single nucleotide polymorphisms (SNPs) were genotyped by the polymerase chain reaction‐based restriction fragment length polymorphism (PCR‐RFLP) analyses. The transmission disequilibrium tests (TDT) of SNPs and haplotype association were carried out using the TDTPHASE program. We found significant genetic association between autism and two of the SNPs of the NRP2 gene (rs849578: P = 0.017, rs849563: P = 0.027), as well as specific haplotypes, especially those formed by rs849563. Furthermore, haplotypes constructed with all markers showed significant excess transmission in both global and individual haplotype analyses (P = 0.004 and 0.017, respectively). The polymorphisms in the NRP2 gene are associated with autism, implying that the NRP2 gene may render individuals to be predisposed to autism. © 2007 Wiley‐Liss, Inc.
Why do young women smoke? IV. Role of genetic variation in the dopamine transporter and lifetime traumatic experience
Authors: Segman Ronnen H. , Kanyas Kyra , Karni Osnat , Lerer Elad , Goltser‐Dubner Tanya , Pavlov Vera , Lerer Bernard 
Published: April 2007

AbstractCigarette smoking is a complex behavior to which environmental, psychological, and genetic factors contribute. Applying a multifactorial model, we examined the role of genetic variation in the dopamine transporter (DAT1) in smoking initiation (SI) and nicotine dependence. The participants were female college students who had never smoked (n = 148) or had smoked daily for at least a year (n = 242). All participants provided extensive background information and completed a series of psychological instruments. Five SNPs were genotyped in the 3′ and 5′ regions of DAT1. Data were analyzed by logistic regression. The best fitting model for SI (P = 1.9 × 10−17, Nagelkerke R2 = 0.33) revealed novelty seeking (OR = 1.14, P = 0.000004) and lifetime traumatic experience (OR = 2.3, P = 0.001) as risk factors and a DAT1_E15 + 274—DAT1_VNTR G‐9 haplotype as protective (OR = 0.57, P = 0.03). In the model for nicotine dependence (P = 1.4 × 10−8, Nagelkerke R2 = 0.27) novelty seeking was a risk factor (OR = 1.07, P = 0.03); the DAT1_E15+274—DAT1_VNTR G‐9 haplotype (OR = 0.37, P = 0.001) and the interaction between trauma and a DAT1_E15 + 274—DAT1_VNTR C‐9 haplotype (OR = 0.15, P = 0.01) were protective. Lifetime experience of trauma was associated with high nicotine dependence among non‐carriers of the C‐9 haplotype but not among carriers of this haplotype. These findings indicate that in the context of a multifactorial model, haplotypes in the 3′ region of DAT1 influence the propensity of young women to initiate smoking as well as the severity of nicotine dependence once the habit is established. A haplotype in the 3′ untranslated region of DAT1 modifies the effect of lifetime traumatic experience on the severity of nicotine dependence. © 2007 Wiley‐Liss, Inc.
Future of neuroprotection for acute stroke: In the aftermath of the SAINT trials
Authors: Savitz Sean I. , Fisher Marc 
Published: April 2007

AbstractThe concept of neuroprotective therapy for acute ischemic stroke to salvage tissue at risk and improve functional outcome is based on sound scientific principles and extensive preclinical animal studies demonstrating efficacy. The failure of most neuroprotective drugs in clinical trials has been due to inadequate preclinical testing and flawed clinical development programs. The Stroke Therapy Academic Industry Roundtable (STAIR) group has outlined rational approaches to preclinical and clinical studies. The positive results from the first Stroke‐Acute‐Ischaemic‐NXY‐Treatment (SAINT‐I) trial of the free‐radical spin‐trap drug, NXY‐059, which followed many of the STAIR guidelines, reinvigorated enthusiasm in neuroprotection, but the SAINT‐II trial did not replicate the positive effect on the same primary prespecified outcome measure. This has led to concerns about the future of neuroprotection as a therapeutic strategy for acute ischemic stroke. We discuss new suggestions to bridge the chasm between preclinical animal modeling and acute human stroke trials to potentially enhance the future assessment of novel neuroprotective drugs. Ann Neurol 2007
Oxygen‐transport properties of liquid‐crystalline polyesters based on 4,4′‐bibenzoic acid
Authors: Hu Y. S. , Wang H. P. , Schiraldi D. A. , Hiltner A. , Baer E. 
Published: April 2007

AbstractThis study examined the oxygen‐transport properties of aromatic liquid‐crystalline (LC) polyesters of 4,4′‐bibenzoic acid (BB) and an aliphatic diol. The effect of the spacer length was probed by the number of methylene groups in the diol being increased from 3 to 6. Parallel studies were performed on polymers in which the LC character was reduced or removed by copolymerization with 30 mol % nonmesogenic isophthalic acid (BB‐30I) or by the replacement of BB with 4,4′‐oxybis(benzoic acid) (OBB). The oxygen‐transport properties were interpreted in terms of the solid‐state structure as revealed by the thermal behavior and wide‐angle X‐ray diffraction. The strong odd–even effect of the spacer length that characterized the thermal transitions of the BB polyesters was weak or absent from the oxygen‐transport properties when the effect of crystallinity was considered. Permeability and diffusivity tended to increase with the spacer length. The lower oxygen permeability of all the BB polyesters compared with that of the BB‐30I copolyesters and the OBB polyesters was due primarily to lower oxygen solubility. The low solubility of the noncrystalline LC phase was ascribed to a smaller free‐volume hole size and possibly to a lower free‐volume hole density in comparison with an amorphous glass. The solubility of oxygen in the noncrystalline regions of the BB‐30I copolyesters and in the amorphous OBB polyesters conformed to the relationship between the solubility and the glass‐transition temperature previously established for amorphous and glassy aromatic polyesters. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 30–37, 2007
Atom transfer radical polymerization of methyl acrylate with molybdenum halides as catalysts in an ionic liquid
Authors: Maria Sebastien , Biedroń Tadeusz , Poli Rinaldo , Kubisa Przemysaw 
Published: April 2007

AbstractThe atom transfer radical polymerization of methyl acrylate in 1‐butyl‐3‐methylimidazolium hexafluorophosphate was studied with a molybdenum halide catalytic system. A combination of a bromine‐containing initiator (ethyl‐2‐bromopropionate) with a chloride‐containing catalyst [MoCl3(PMe3)3/MoCl4(PMe3)3] led to a controlled polymerization, and matrix‐assisted laser desorption/ionization time‐of‐flight analysis of the polymers indicated that the reversibly deactivated macromolecules contained both bromine and chloride end groups. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 278–281, 2007
Influence of thermal history on the nonisothermal crystallization of poly(L‐lactide)
Authors: Masirek R. , Piorkowska E. , Galeski A. , Mucha M. 
Published: April 2007

AbstractThe effect of thermal history on the nonisothermal crystallization of poly(L‐lactide) (PLA) was studied. The cold crystallization of PLA by heating from the glassy state was dominated by the heating rate. However, the temperature to which PLA was cooled before crystallization markedly affected the crystallization kinetics. The lower the temperature was to which PLA was cooled, the lower the nonisothermal crystallization peak temperature was and the larger the crystallization enthalpy was, which indicated enhanced nucleation of spherulites. Fast heating from the glassy state reduced the time available for the growth of spherulites and also suppressed the number of nuclei stable at elevated temperatures by limiting the recrystallization of nuclei formed at low temperatures and their overgrowth by thicker and more perfect crystals. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 282–290, 2007
Deformation mechanism of nylon 6/layered silicate nanocomposites: Role of the layered silicate
Authors: Kim G.‐M. , Goerlitz S. , Michler G. H. 
Published: April 2007

AbstractPolymer/layered silicate nanocomposites, depending on the molecular weight of nylon 6 as the matrix, were prepared through melt blending with a twin‐screw extruder to study their morphology and the role of layered silicates (i.e., montmorillonite) on local deformation processes. A thermal analysis of the nanocomposites was performed with differential scanning calorimetry. The dispersion of the layered silicates and nanocomposite morphology were investigated with wide‐angle X‐ray scattering and transmission electron microscopy. The results showed that the layered‐silicate surfaces predominantly induced γ‐form crystals of nylon 6, whereas α‐form crystals were nucleated far away from the clay surface. The fraction of γ‐form crystals and the degree of exfoliation increased with the molecular weight of the nylon 6 matrix. In a high‐molecular‐weight nanocomposite, a well‐defined exfoliated nanomorphology was observed, in which fine nylon 6 lamellae were most likely to be oriented with their planes perpendicular to the injection‐molding direction, although to a great extent the layered silicates were arranged on planes parallel to the injection‐molding direction. On the contrary, a mixed nanomorphology appeared in a low‐molecular‐weight nanocomposite, intercalated and exfoliated nanomorphologies coexisting; the layered silicates were randomly dispersed in the nylon 6 matrix, and the nylon 6 lamellae grew in no preferential direction with respect to the layered‐silicate surface. The dispersion of the layered silicates and the orientation of the layered silicates as well as the lamellae were directly reflected in the mechanical deformation processes. The results of in situ deformation experiments under a high‐voltage electron microscope (1000 kV) indicated that the main deformation mechanism was microvoid formation either within the intercalated tactoids or in the vicinity of layered silicates in the matrix for intercalated and exfoliated nanomorphology systems, respectively. In the exfoliated nanocomposite, that is, the high‐molecular‐weight nanocomposite, the external applied stresses were much more effectively transferred from the polymer matrix to the layered silicates; furthermore, microvoid formation took place more uniformly and homogeneously throughout the deformed specimen, and thus a well‐improved stiffness/strength/ toughness balance was achieved in comparison with the mixed nanomorphology system (the low‐molecular‐weight nanocomposite). © 2007 Wiley Periodicals, Inc. JAppl Polym Sci 105: 38–48, 2007
Refractive‐index anisotropy and optical dispersion in films of deoxyribonucleic acid
Authors: Samoc Anna , Miniewicz Andrzej , Samoc Marek , Grote James G. 
Published: April 2007

AbstractWe have determined the refractive indices in the directions parallel and perpendicular to the surface plane of films of deoxyribonucleic acid (DNA) and their wavelength dispersion. These parameters are fundamental for understanding the properties of waveguiding structures containing DNA‐based photonic materials. The orientation of DNA molecules in films and their optical properties are sensitive to the film fabrication and environmental conditions influencing the structure. Prism coupling measurements show ambient‐humidity‐related changes in the refractive index, birefringence, and anisotropy of the alignment of the DNA molecules in the films studied. These films were 0.5–5 μm thick, were prepared by both spin coating and casting from aqueous solutions containing 0.1–3 wt % DNA, and were measured in ambient air with relative humidities of 37–58%. The optical properties of the films and the orientation of the DNA molecules are discussed with respect to the mechanism for the formation of the polymer liquid‐crystalline phases during film deposition. The dispersion of the refractive indices in films of native DNA has been derived from interference fringes in absorption and reflection spectra in the wavelength range of 350–2700 nm through the fitting of the positions of the fringes with the Sellmeier dispersion formula in combination with the prism coupling data. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 236–245, 2007
Silicon carbonitride thin‐film coatings fabricated by remote hydrogen–nitrogen microwave plasma chemical vapor deposition from a single‐source precursor: Growth process, structure, and properties of the coatings
Authors: Wrobel A. M. , Blaszczyk‐Lezak I. , Walkiewicz‐Pietrzykowska A. 
Published: April 2007

AbstractSilicon carbonitride (Si:C:N) films were produced by remote hydrogen–nitrogen microwave plasma chemical vapor deposition (RP‐CVD) from a 1,1,3,3‐tetramethyldisilazane precursor with a nitrogen content {[N2]/([H2] + [N2])} of 0.88 in the plasma‐generating mixture and a substrate temperature in the range of 30–400°C. The effects of the substrate temperature on the rate and yield of the RP‐CVD process and chemical structure (examined by Fourier transform infrared spectroscopy) of the resulting films were investigated. The Si:C:N film properties were characterized in terms of the density, hardness, elastic modulus, and friction coefficient. With the IR structural data, reasonable structure–property relationships were determined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 122–129, 2007
Glass transition as a key to identifying solid phases
Authors: Wunderlich Bernhard 
Published: April 2007

AbstractThe earlier suggested definition, “a solid is a condensed phase at a temperature below its glass transition,” has developed into the key to the understanding of macromolecular materials. Its importance and implications for the understanding of not only polymers but all materials are reviewed in this article. A macromolecular sample can be a system consisting of a single amorphous phase or be a molecularly coupled multiphase system of different degrees of order and metastability in its subsystems. It is well known that liquid crystals, plastic crystals, and conformationally disordered crystals are still ordered above the glass transition, but recently even the monoclinic crystals of poly (oxyethylene) have been shown to have an additional glass transition below the melting temperature. This supports the inference that in the delineation of the solid state, the glass transitions take preference to melting transitions. The main tools for recognizing the different equilibrium and nonequilibrium phases are differential scanning calorimetry and temperature‐modulated differential scanning calorimetry. Such calorimetry yields quantitative heat capacities to be interpreted in terms of molecular motion and latent heats. Separated into reversible and irreversible contributions, the entropy changes connected to ordering and disordering can be evaluated. The value of the recognition of phase transitions lies in the fact that materials must be pliable for being manufactured into a final shape but often need high modulus and strength in their applications. Near the glass transition, forming is easy, whereas below the glass‐transition temperature, a high modulus is reached for properly oriented polymer molecules. By the identification of the glass transitions of materials with different states of order, a better understanding of the solid state of soft materials is reached. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 105: 49–59, 2007
Block copolymers of cyclohexene oxide and ketonic resins via condensation and promoted cationic polymerization
Authors: Ergun Selin , Kızılcan Nilgün , Önen Ayşen 
Published: April 2007

AbstractBlock copolymers of cyclohexene oxide (CHO) and ketonic resin were prepared by using ketonic resins as free radical photoinitiators via two‐step procedure. In the first step, cyclohexanone–formaldehyde and acetophenone–formaldehyde resins were modified during their preparation with benzoin and benzoin isobutyl ether. Then, AB or ABA type block copolymers depending on the resin employed were obtained by irradiation of these resins in the presence of pyridinium salt and CHO as a cationically polymerizable monomer. By this way, block copolymers of CHO with ketonic resin were prepared and characterized by GPC, DCS, FTIR, and 1H NMR spectral measurements. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Self‐assembly of pH‐responsive acrylate latex particles at emulsion droplets interface
Authors: He Xiao Dong , Ge Xue Wu , Liu Hua Rong , Deng Ming Ge , Zhang Zhi Cheng 
Published: April 2007

AbstractThe self‐assembly of pH‐responsive poly (methyl methacrylate‐co‐acrylic acid) latex particles at emulsion droplet interfaces was achieved. Raising pH increases the hydrophilicity of the latex particles in situ and the latex particle acts as an efficient particulate emulsifier self‐assembling at emulsion droplet interface at around pH 10–11 but exhibits no emulsifier activity at higher pH. This effect can be reversibly induced simply by varying the aqueous phase pH and thus the latex emulsifier can be reassembled. The effect factors, including the aqueous phase pH, the surface carboxyl content, ζ‐Potential of the latex particles and oil phase solvent have been investigated. Using monomer as oil phase, the latex particles could stabilize emulsion droplets during polymerization and cage‐like polymer microspheres with hollow core/porous shell structure were obtained after polymerization. The mechanism of the latex particles self‐assembly was discussed. The morphologies of emulsion and microspheres were characterized by optical microscopy, scanning electron microscopy, and transmission electron microscopy. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007
Effects of amphoteric copolymer structure on the properties of barium titanate suspensions
Authors: Chen Chin‐Hao , Hsu Kung‐Chung 
Published: April 2007

AbstractThe effect of the molecular structure of an amphoteric copolymer, i.e., poly[acrylamide/(α‐N,N‐dimethyl‐N‐(3‐(β‐carboxylate)acrylamino)propyl)ammonium ethanate)] (PAD) on the interactions with BaTiO3 (BT) particles in water and on the stability of BT suspensions was examined by means of adsorption, ζ potential, sedimentation, and viscosity measurements. The results indicate that the adsorption of PAD onto BT particles follows the Langmuir adsorption isotherm. As the added PAD containing greater ionic group fraction, both the saturated amount of adsorbed polymer and the amount of the polymer required to reach the minimal ζ potential decrease. Whatever the ionic group fraction in PAD, BT suspensions become stable and less viscous when saturated amount of the polymer was adsorbed on particle surface. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007