bluuebunny/crossref_metadata_2025_split huggingface dataset:
Dopamine beta‐hydroxylase (DBH) activity and ‐1021C/T polymorphism of DBH gene in combat‐related post‐traumatic stress disorder
Authors: Mustapić Maja , Pivac Nela , Kozarić‐Kovačić Dragica , Deželjin Martina , Cubells Joseph F. , Mück‐Šeler Dorotea 
Published: September 2007

AbstractThe roles of dopamine (DA) and norepinephrine (NE) in posttraumatic stress disorder (PTSD) are unclear. The aim of the study was to determine plasma dopamine beta‐hydroxylase (DBH) activity and DBH‐1021C/T gene polymorphism in combat veterans with (N = 133) or without (N = 34) chronic PTSD. Similar frequencies in genotype or allele distribution were found between veterans with or without PTSD. War veterans with PTSD had lower DBH activity, associated with the DBH‐1021C/T variant in DBH genes, than veterans without PTSD. A significantly lower plasma DBH activity was found in combat veterans with PTSD carrying the CC genotype as compared to veterans without PTSD carrying the corresponding genotype. Since both groups were exposed to the same trauma, it is possible that a pre‐existing trait difference in regulation of NE function contributed to a differential vulnerability to develop PTSD, or that the regulation of DBH expression was different in response to trauma. The results suggest that that genotype‐controlled measurement of plasma DBH activity might be used as a potential biological marker of the response to trauma, and that further studies of DBH and other loci related to DA and NA in PTSD are warranted. © 2007 Wiley‐Liss, Inc.
Polyacrylate/(carboxymethylcellulose modified montmorillonite) superabsorbent nanocomposite: Preparation and water absorbency
Authors: Qiu Haixia , Yu Jiugao 
Published: September 2007

AbstractMontmorillonite (MMT) was modified with carboxymethylcellulose (CMC). The X‐ray diffraction (XRD) and FTIR analyses showed that the CMC chains had intercalated into the MMT sheets, and the strong chemical interaction between the ether bonds from CMC and SiO bonds from MMT was the driving force for intercalation. Polyacrylate (PAA)/modified MMT superabsorbent nanocomposites were fabricated by effectively dispersing the modified MMT in acrylic acid solution and polymerizing the acid. The superabsorbent composites were characterized by XRD, TEM, and FTIR. The influence of modified MMT, weight ratio of CMC to MMT, and modified MMT content in the nanocomposites on the water absorbency was investigated. Results showed that the introduction of pure MMT could decrease the water absorbency of the gel, but adding modified MMT could not only effectively increase the water absorbency of the gel, but also improve its water retention ability. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Elastic effects on solubility in semicrystalline polymers
Authors: Serna L. V. , Becker J. L. , Galdámez J. R. , Danner R. P. , Duda J. L. 
Published: September 2007

AbstractCapillary column inverse gas chromatography experiments at infinite solvent dilution were conducted for 15 polyethylene/solvent systems. Thermodynamic data were collected for various types of penetrant molecules (normal alkanes, 1‐alkenes, isomers of hexane, and ring compounds). Theoretical predictions of the solubility data were made with an activity coefficient model (Universal Functional Group Activity‐van der Waals‐Free‐Volume) (UNIFAC‐vdw‐FV) and an equation‐of‐state model (Group‐Contribution, Lattice‐Fluid, Equation of State) (GCLF‐EoS). Although good agreement between the experimental data and theoretical predictions was obtained above the melting point of the polymer, at temperatures below the melting point, significant differences were found. This occurred because at those temperatures, the polymer had a semicrystalline structure and the solubility of the solvent was reduced on account of the constraints on some of the chains in the amorphous phase by the polymer crystallites. The theory developed by Michaels and Hausslein to account for such elastic effects on solubility was incorporated into the two predictive models. After these modifications, the new estimations of the solubility showed significantly improved agreement with the experimental results. Moreover, the elasticity effect resulted in elevated estimates of the crystallinity when inverse gas chromatography retention volumes were used. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Remote polymerization of coatings with the release of borane from its amine complex
Authors: Fedorov Andrei V. , Ermoshkin Andrey A. , Neckers Douglas C. 
Published: September 2007

AbstractWe defineremote polymerizationas the formation of a photopolymer without the benefit of either light or a photoinitiator. In the reported experiments, a radical‐generating trialkylborane–oxygen system was used with an active trialkylborane that was released from its stable amine complex by a vaporous (i.e., gas‐phase) reagent. Acrylates and methacrylates were polymerized after oxidative radical formation from the highly reactive borane. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Lignins for phenol replacement in novolac‐type phenolic formulations. II. Flexural and compressive mechanical properties
Authors: Tejado A. , Kortaberria G. , Peña C. , Blanco M. , Labidi J. , Echeverría J. M. , Mondragon I. 
Published: September 2007

AbstractSeveral hexamethylenetetraamine‐cured novolac‐type lignophenolic resins have been subjected to mechanical analysis to check the influence of the addition of different types of lignins (kraft pine lignin, soda/anthraquinone flax lignin, and sulfonated kraft lignin from mixed softwoods) and the influence of different phenol substitution levels. Both flexural and compression tests have been performed to evaluate the influence of the curing temperature and pressure. The results have been compared with those from a commercial novolac system. Flexural tests show that lignin incorporation leads to systems with increased rigidity, whereas up to 82% of the maximum strength can be retained with respect to a commercial phenolic (phenol–formaldehyde) at a 45 wt % substitution degree. Compression analyses show that modified prepolymers are not significantly affected by the presence of lignin at a medium curing pressure (150 bar), but their deformability results considerably increase at high curing pressures (400 or 600 bar). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Environmentally friendly mixed tannin/lignin wood resins
Authors: Lei Hong , Pizzi A. , Du Guanben 
Published: September 2007

AbstractWe obtained lignin‐based wood adhesives satisfying the requirements of relevant international standards for the manufacture of wood particleboard. These were based on two different low‐molecular‐mass lignins. These lignin‐based wood adhesives did not use any formaldehyde in their formulation; formaldehyde was substituted with a nonvolatile nontoxic aldehyde, namely, glyoxal. The last formaldehyde present, contributed by a fortifying synthetic phenol–formaldehyde resin, was also eliminated by the substitution of the phenol–formaldehyde resin with a natural, vegetable polyflavonoid tannin extract to which no aldehyde was added. This substitution brought the total content of natural material up to 80 wt % of the total adhesive. The adhesives yielded good internal bond strength results of the panels, enough to pass relevant international standard specifications for interior‐grade panels. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Diversity of fish and fisheries from the Lake Encantada Environmental Protection Area, Ilhéus, Brazil
Authors: Rocha G.R.A. , Schiavetti A. 
Published: September 2007

Abstract
Lake Encantada, in the basin of the Almada River (Bahia State), has an area of 650.5 ha and a perimeter of 13.3 km. In 1993, an area of 11 800 ha around the lake was designated an Environmental Protection Area (Class V category). The main goal of this study was to identify fish species in the lake and to determine possible threats to their conservation.
Fish samples were obtained with gillnets between May 2002 and February 2004, and used to calculate indices of species diversity Shannon (H′), richness (d) and evenness (J′).
Eleven fish species comprising nine families were collected during the sampling period. Three introduced species occurred in the lake: Prochilodus argenteus, endemic to the São Francisco river basin, and two African species, Oreochromis niloticus and Clarias gariepinus. In overall ranking, Prochilodus argenteus was first in number of individuals (46%) and weight (59%), followed by Genidens genidens in numbers (31%), and Clarias gariepinus in weight (15%).
The occurrence and dominance of introduced species is discussed as well as their possible impacts on the trophic structure of this ecosystem.
Copyright © 2007 John Wiley & Sons, Ltd.
Epithelial and Muscular Regionalization of the Human Developing Anorectum
Authors: Fritsch Helga , Aigner Felix , Ludwikowski Barbara , Reinstadler‐Zankl Sandra , Illig Romana , Urbas Dieter , Schwarzer Christoph , Longato Stefano 
Published: September 2007

AbstractIn the past, interpretations of anorectal development were mainly based on analysis of serially sectioned embryos of various nonhuman species as well as some human specimens. A four‐dimensional view of the developmental situation in the human has never been established nor connected to recent findings obtained from newer molecular techniques. We, therefore, investigated human embryonic and fetal pelves by means of immunohistochemistry and in situ hybridization to elucidate differentiation and interaction of epithelial and mesenchymal layers of the anorectum. To emphasize spatial as well as sequential morphological development, we produced three‐dimensional reconstructions of the specimens at hand. Research conducted proved that the decisive steps of epithelial and muscular differentiation occur between the 7th and 9th week after conception. This study elucidates a biphasic epithelial “closure” in the anal canal and interactions between epithelium, smooth musculature, and skeletal musculature. Based on the results presented here, it is possible to describe the pathogenesis of two anorectal malformations: the imperforate anal membrane and the anal membrane stenosis. This study will now provide the basis for further research into developmental processes occurring before the ones examined. Anat Rec, 1449‐1458, 2007. © 2007 Wiley‐Liss, Inc.
Understanding user acceptance of multimedia messaging services: An empirical study
Authors: Lee Matthew K.O. , Cheung Christy M.K. , Chen Zhaohui 
Published: September 2007

AbstractMultimedia Messaging Services (MMS) is a new medium that enriches people's personal communication with their business partners, friends, or family. Following the success of Short Message Services, MMS has the potential to be the next mobile commerce “killer application” which is useful and popular among consumers; however, little is known about why people intend to accept and use it. Building upon the motivational theory and media richness theory, the research model captures both extrinsic (e.g., perceived usefulness and perceived ease of use) and intrinsic (e.g., perceived enjoyment) motivators as well as perceived media richness to explain user intention to use MMS. An online survey was conducted and 207 completed questionnaires were collected. By integrating the motivation and the media richness perspectives, the research model explains 65% of the variance. In addition, the results present strong support to the existing theoretical links as well as to those newly hypothesized in this study. Implications from the current investigation for research and practice are provided.
Browsing and searching in a faceted information space: A naturalistic study of PubMed users' interaction with a display tool
Authors: Tang Muh‐Chyun 
Published: September 2007

AbstractThe study adopts a naturalistic approach to investigate users' interaction with a browsable MeSH (medical subject headings) display designed to facilitate query construction for the PubMed bibliographic database. The purpose of the study is twofold: first, to test the usefulness of a browsable interface utilizing the principle of faceted classification; and second, to investigate users' preferred query submission methods in different problematic situations.An interface that incorporated multiple query submission methods—the conventional single‐line query box as well as methods associated the faceted classification display was constructed. Participants' interactions with the interface were monitored remotely over a period of 10 weeks; information about their problematic situations and information retrieval behaviors were also collected during this time. The traditional controlled experiment was not adequate in answering the author's research questions; hence, the author provides his rationale for a naturalistic approach.The study's findings show that there is indeed a selective compatibility between query submission methods provided by the MeSH display and users' problematic situations. The query submission methods associated with the display were found to be the preferred search tools when users' information needs were vague and the search topics unfamiliar.The findings support the theoretical proposition that users engaging in an information retrieval process with a variety of problematic situations need different approaches. The author argues that rather than treat the information retrieval system as a general purpose tool, more attention should be given to the interaction between the functionality of the tool and the characteristics of users' problematic situations.
Statistical Methods for Anomalous Discrete Time Series Based on Minimum Cell Count
Authors: Wu Chih‐Chieh , Grimson Roger C. , Amos Christopher I. , Shete Sanjay 
Published: September 2007

AbstractTemporal incidence patterns of point epidemics often contain periods of unusually low or high frequencies. Identifying variations in incidence frequencies, which may be caused by changes in exposure to infectious or environmental agents, may provide important insights into the pathogenesis or etiology of a disease. We propose and formulate new statistical tests for temporal and space‐time anomalies that are based on the minimum frequency in a unit of time and that are meaningful for the characteristic incidence patterns of the cases studied. Among the most widely applied methods are the Ederer–Myers–Mantel test, the Maxima test, and the scan test, which are all sensitive to the maximum frequency within a short period of time. We elucidate the importance and utility of our new tests and the existing tests and suggest a systematic statistical analysis of reported disease anomalies using these tests combined. Data on a temporal series of adolescent suicide from the US National Center for Health Statistics were analyzed using these methods. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination and pharmacokinetic study of norcantharidin in human serum by HPLC‐MS/MS method
Authors: Wei Chun‐min , Zhang Rui , Wang Ben‐jie , Yuan Gui‐yan , Guo Rui‐chen 
Published: September 2007

AbstractA sensitive, simple and selective high‐performance liquid chromatography–tandem mass spectrometry method was developed and applied to the determination of norcantharidin concentration in human serum. Norcantharidin (NCTD) and cyclophosphamide (IS) in serum were extracted with acetone, separated on a C18 reversed‐phase column, gradiently eluted with a mobile phase of acetonitrile–water containing 2 mm ammonium acetate and 0.1% formic acid (pH 3), ionized by positive ion pneumatically assisted electrospray and detected in the multi‐reaction monitoring mode using precursor → product ions of m/z 169.3 → 123.1 for NCTD and 261.2 → 140.2 for IS, respectively. The linear range of the calibration curve for NCTD was 2.5–50 ng/mL, with a lowest limit of quantification of 2.5 ng/mL, and the intra/inter‐day RSD was less than 10%. The method was suitable for determination of low NCTD concentration in human serum after therapeutic oral doses, and has been successfully used for pharmacokinetic studies in healthy Chinese volunteers. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous determination of harpagoside and cinnamic acid in rat plasma by liquid chromatography electrospray ionization mass spectrometry and its application to pharmacokinetic studies
Authors: Wang Su‐Jun , Ruan Jin‐Xiu , Zhao Yan‐Hong , Zhang Zhen‐Qing 
Published: September 2007

AbstractA simple and sensitive method was developed for the simultaneous quantification of harpagoside and cinnamic acid in rat plasma using high‐performance liquid chromatography system coupled to a negative ion electrospray mass spectrometric analysis. The plasma sample preparation was a simple deproteinization by the addition of two volumes of acetonitrile. The analytes were separated on an Intersil C8‐3 column (2.1 mm i.d. × 250 mm, 5 µm) with acetonitrile–5 mm ammonium formate aqueous solution (60:40, v/v) as mobile phase at a flow‐rate of 0.2 mL/min. Detection was performed on a quadrupole mass spectrometer equipped with electrospray ionization (ESI) source operated under selected ion monitoring (SIM) mode. [M + HCOO]− at m/z 539 for harpagoside, [M − H]− at m/z 147 for cinnamic acid and [M − H]− at m/z 137 for salylic acid (internal standard) were selected as detecting ions, respectively. The method was validated over the concentration range 7–250 ng/mL for harpagoside and 5–500 ng/mL for cinnamic acid. The lower limits of quantitation for harpagoside and cinnamic acid were 7 and 5 ng/mL, respectively. The intra‐ and inter‐day precisions (RSD%) were within 9.5% and the assay accuracies (RE%) ranged from −5.3 to 3.0% for both analytes. Their average recoveries were greater than 86%. Both analytes were proved to be stable during all sample storage, preparation and analysis procedures. The method was successfully applied to the pharmacokinetic study of harpagoside and cinnamic acid following oral administration of Radix Scrophulariae extract to rats. Copyright © 2007 John Wiley & Sons, Ltd.
Determination of glucosamine in horse plasma by liquid chromatography tandem mass spectrometry
Authors: Beaudry Francis , Vachon Pascal 
Published: September 2007

AbstractGlucosamine is an amino sugar involved in the biosynthesis of glycosylated proteins and lipids. Recently, with increased public interest in natural products medicine, glucosamine has been widely used to treat osteoarthritis, even though demonstrations of its actual efficacy remain relatively unknown. Information related to the pharmcokinetics of glucosamine is sparse. A recent analytical method published used 13C‐glucosamine as an internal standard to analyse study samples. The method lacked accuracy owing to an important natural isotopic contribution of glucosamine to 13C‐glucosamine ion abundance. This manuscript describes a simple method to quantify glucosamine in horse plasma. Glucosamine was extracted by protein precipitation with acetonotrile containing 0.1% formic acid. The chromatography was performed on a Agilent Hypersil‐ODS 100 × 2.1 mm column with a mobile phase composed of acetonitrile and 0.5% formic acid in water (45:55) at a flow rate of 0.3 mL/min. A linear (1/x) relationship was used to perform the calibration over an analytical range of 10–1000 ng/mL. The inter‐batch precision and accuracy ranged from 5.3 to 11.3% and from 87.8 to 107.2% in horse plasma, respectively. The mean endogenous level of glucosamine in horse plasma was 14.4 ng/mL (n = 6). This LC‐ESI/MS/MS method for the determination of glucosamine in horse plasma provided results within generally accepted criteria used for bioanalytical assay. Copyright © 2007 John Wiley & Sons, Ltd.
Round‐robin evaluation of a solid‐phase microextraction–gas chromatographic method for reliable determination of trace level ethylene oxide in sterilized medical devices
Authors: Harper Thomas , Cushinotto Lisa , Blaszko Nancy , Arinaga Julie , Davis Frank , Cummins Calvin , DiCicco Michael 
Published: September 2007

AbstractMedical devices that are sterilized with ethylene oxide (EtO) retain small quantities of EtO residuals, which may cause negative systemic and local irritating effects, and must be accurately quantified to ensure non‐toxicity. The goal of this round‐robin study is to investigate the capability of a novel solid‐phase microextraction–gas chromatographic (SPME‐GC) method for trace‐level EtO residuals analysis: three independent laboratories conducted a guided experiment using this SPME‐GC method, in assessing method performance, ruggedness and the feasibility of SPME fibers. These were satisfactory across the independent laboratories, at the 0.05–5.00 ppm EtO range. This method was then successfully applied to analyze EtO residuals in several sterilized/aerated medical devices of various polymeric composition, reliably detecting and quantifying the trace levels of EtO residuals present (∼0.05 ppm EtO). SPME is a feasible alternative for quantifying trace‐level EtO residuals in sterilized medical devices, thereby lowering the limit of quantification (LOQ) by as much as two to three orders of magnitude over the current GC methodology of direct liquid injection. Copyright © 2007 John Wiley & Sons, Ltd.
Simultaneous determination of dipyridamole and salicylic acid in human plasma by high performance liquid chromatography‐mass spectrometry
Authors: Wang Na , Xu Fengguo , Zhang Zunjian , Yang Cheng , Sun Xiuhong , Li Jinheng 
Published: September 2007

AbstractA sensitive, rapid and simple high‐performance liquid chromatography–electrospray ionization–mass spectrometry (HPLC‐ESI‐MS) method for simultaneous determination of dipyridamole and salicylic acid in human plasma has been developed and validated. After the addition of diazepam and rosiglitazone as internal standard (IS), plasma samples were prepared by liquid–liquid extraction followed by an isocratic elution with methanol:2 mm ammonium acetate buffer (pH 4.25; 70/30, v/v) on a Shimadzu VP‐ODS C18 column (5 µm, 150 × 2.0 mm I.D.). Detection was performed on a quadrupole mass spectrometer with ESI interface operating in the positive‐ion mode for dipyridamole and negative‐ion mode for salicylic acid. Calibration curves were linear (r2 > 0.99) over the concentration range 10–2500 ng/mL for dipyridamole and 30–4000 ng/mL for salicylic acid with acceptable accuracy and precision, respectively. The intra‐ and inter‐batch precisions were less than 15% of the relative standard deviation. The limits of detection of dipyridamole and salicylic acid were 1 and 15 ng/mL, respectively. The validated HPLC‐ESI‐MS method was successfully applied to a preliminary pharmacokinetic study of fixed‐dose combination of sustained‐release dipyridamole/aspirin in Chinese healthy male volunteers. Copyright © 2007 John Wiley & Sons, Ltd.