bluuebunny/crossref_metadata_2025_split huggingface dataset:
Active immunisation against gastric inhibitory polypeptide (GIP) improves blood glucose control in an animal model of obesity-diabetes
Authors: Irwin Nigel , McClean Paula L. , Patterson Steven , Hunter Kerry , Flatt Peter R. 
Published: October 2008

Abstract
Recent research suggests that long-term ablation of gastric inhibitory polypeptide (GIP) receptor signalling can reverse or prevent many of the metabolic abnormalities associated with dietary and genetically induced obesity-diabetes. The present study was designed to assess the sub-chronic effects of passive or active immunisation against GIP in ob/ob mice. Initial acute administration of GIP antibody together with oral glucose in ob/ob mice significantly increased the glycaemic excursion compared to controls (p<0.05). This was associated with a significant reduction (p<0.05) in the overall glucose-mediated insulin response. However, sub-chronic passive GIP immunisation was not associated with any changes in body weight, food intake or metabolic control. In contrast, active immunisation against GIP for 56 days in young ob/ob mice resulted in significantly (p<0.05) reduced circulating plasma glucose concentrations on day 56 compared to controls. There was a tendency for decreased circulating insulin in GIP immunised mice. The glycaemic response to intraperitoneal glucose was correspondingly improved (p<0.05) in mice immunised against GIP. Glucose-stimulated insulin levels were not significantly different from controls. Furthermore, insulin sensitivity was similar in mice immunised against GIP and respective controls. Overall, the results reveal that active, as opposed to passive, immunisation against GIP improves blood glucose control ob/ob mice.
Biochemical characterization of the catalytic domains of three different clostridial collagenases
Authors: Eckhard Ulrich , Schönauer Esther , Ducka Paulina , Briza Peter , Nüss Dorota , Brandstetter Hans 
Published: October 2008

Abstract
Clostridial collagenases are used for a broad spectrum of biotechnological applications and represent prime target candidates for both therapy and diagnosis of clostridial infections. In this study, we biochemically characterized the catalytic domains of three clostridial collagenases, collagenase G (ColG) and H (ColH) from Clostridium histolyticum, and collagenase T (ColT) from C. tetani. All protein samples showed activity against a synthetic peptidic substrate (furylacryloyl-Leu-Gly-Pro-Ala, FALGPA) with ColH showing the highest overall activity and highest substrate affinity. Whereas the K
m values of all three enzymes were within the same order of magnitude, the turnover rate k
cat of ColG decreased 50- to 150-fold when compared to ColT and ColH. It is noteworthy that the protein N-terminus significantly impacts their substrate affinity and substrate turnover as well as their inhibition profile with 1,10-phenanthroline. These findings were complemented with the discovery of a strictly conserved double-glycine motif, positioned 28 amino acids upstream of the HEXXH zinc binding site, which is critical for enzymatic activity. These observations have consequences with respect to the topology of the N-terminus relative to the active site as well as possible activation mechanisms.
Characterization of Local Strain Distribution in Zircaloy-4 and M5® Alloys
Authors: Elbachiri Kamal , Doumalin Pascal , Crépin Jérôme , Bornert Michel , Barberis Pierre , Rebeyrolle Véronique , Bretheau Thierry 
Published: October 2008

Abstract
Zirconium alloys with low alloying content are mainly used in the nuclear industry as structural materials because of their superior properties in terms of neutron transparency, mechanical strength, and corrosion resistance. In order to further improve the corrosion resistance as well as the integrity of Zr based cladding tubes under severe thermomechanical loading, the M5® alloy was developed to replace stress-relieved Zircaloy-4. An experimental study conducted at the macroscopic scale between 20 and 500°C shows that the mechanical behavior of the studied Zr based alloys depends on the metallurgical state (stress-relieved or recrystallized) rather than on the chemical composition. To try to understand these mechanical differences, an experimental multiscale investigation was devised at ambient temperature (20°C) in order to characterize the strain distribution at the scale of the grains and at that of the representative volume element. Local strain fields were measured by means of a microscale digital image correlation technique, based on microgrid deposits and scanning electronic microscopy (SEM). Tensile tests were performed inside the SEM chamber. Here, the original method of strain distribution quantification based on statistical strain field analysis is used. First, this analysis reveals a particular strain distribution consisting of bands with an orientation greater that 45° with regards to the direction of macroscopic tension, and second, shows that these interaction lengths are much greater than the average size of the grains, which clearly demonstrates that local investigations cannot be limited to a few grains. Therefore, the macroscopic mechanical response of these materials is not only governed by intragranular heterogeneities but by the local deformations which become organized between the grains in a pattern of bands at a mesoscale, which is determined by medium to long-range interactions. The difference of values in the band characteristics could partly explain the anisotropic global behavior of these materials linked with their microstructure.
Condensation Damage Behind Self-Adhering Membrane Flashing and Interior Furnishings on Exterior Residential Walls
Authors: Ofori-Amanfo Collins , Spink Matthew J. 
Published: October 2008

Abstract
This paper will present case studies of condensation damage behind self-adhering membranes installed around windows and other penetrations in exterior walls, as well as case studies of condensation damage behind large interior furnishings installed on the interior surfaces of exterior walls, and in unventilated spaces in Minnesota. The self-adhering membranes that are often used to integrate water-resistive barriers with residential doors and windows can, under certain conditions, lead to condensation and subsequent damage. While wider membranes help prevent inward movement of liquid water to the sheathing and stud framing, they also inhibit outward movement of interior water vapor. By increasing the distance that outward moving vapor must travel, wide membrane flashings trap moisture that can condense in cold climates and cause deterioration of degradable materials. In cold climate regions, condensation damage can also occur in exterior walls behind furnishings such as large mirrors and large cabinets. These interior decorations act as thermal reflectors and prevent interior heat from migrating into the exterior walls. When moisture behind these thermal reflectors is cooled below the dew point, condensation and related deterioration of the wall framing can occur. This paper discusses suggestions for the width of applied self-adhered membranes in cold climate regions and recommends locations for thermally reflecting interior furnishings.
XRF, XRD, and Thermal Analysis Techniques for Quantitative Determination of Portland Cement and Slag Cement Constituents
Authors: Vidican Ioana , Phan Binh , Farr Jerry , Norton Newell 
Published: October 2008

Abstract
Two rapid test methods to determine and quantify sulfate forms in cement are presented—DSC and XRD. The DSC method is applicable to hydrated calcium sulfates: gypsum and bassanite. Its description includes preparation of standards, calibration curves, and calculation of hydrated sulfates in an unknown cement sample. The XRD method is used qualitatively and quantitatively for both hydrated and nonhydrated sulfate forms. The qualitative approach is used to identify the presence of sulfates in cement samples. The quantitative approach describes the Rietveld analysis applied to a cement sample containing gypsum, bassanite, anhydrite, and arcanite. The calculated total SO3 content is compared with another direct analytical technique (Sulfur Analyzer). The other two methods used to determine the amount of granulated blast furnace slag added to cement are discussed—DTA and XRD. With the DTA method, the exothermic peak that accompanies slag devitrification at high temperatures is measured and converted in slag percentages. The method’s description includes preparation of standards, calibration curve, and calculation of slag content of an unknown cement sample. The XRD method works as a qualitative tool to show the effect of amorphous slag to a cement diffractogram as well as a quantitative tool (Rietveld analysis using an internal standard). Rietveld analysis on cement containing slag samples is used with XRF oxide analysis to correct the Bogue formula calculation for C3S. Three different calculations/corrections are discussed showing reasonably good approximate results.
Chromium occurrence and speciation in Baltimore Harbor sediments and porewater, Baltimore, Maryland, USA
Authors: Graham Andrew M. , Wadhawan Amar R. , Bouwer Edward J. 
Published: October 2008

Abstract
Industrial activities in the Baltimore Harbor, Baltimore, Maryland, USA, have resulted in widespread chromium contamination of sediments. A comprehensive analysis of Cr speciation in sediment and porewater collected from 22 locations in the Baltimore Harbor was completed to understand Cr bioavailability and probability of toxicity due to Cr in sediments. The analysis employed a reverse-phase ion-pair high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) method. Sub-microgram-per-liter determination of Cr(III) and Cr(VI) in environmental samples was found, with method validation revealing broad method applicability of HPLC-ICP-MS to a wide range of sample types. The major limitation of the method was poor Cr species separation in high ionic strength solutions (greater than 0.1 M NaCl). Total Cr concentrations in Baltimore Harbor sediments ranged from 2.5 to 1,050 mg/kg with 11 of the 22 sites containing total Cr in excess of the 370 mg/ kg effects range-median (ER-M) sediment quality guideline. The Cr(VI) concentrations in sediments, however, were markedly lower, ranging from 0.10 to 0.38 mg/kg with Cr(VI) not detected in 14 of the 22 stations. Porewater concentrations, both for total Cr and Cr(VI), were quite low, with total Cr ranging from 0.20 to 2.16 μg/L and Cr(VI) ranging from 0.73 to 1.17 μg/L. The Cr(VI)-reducing capacity of the sediments, based on a sediment-spiking experiment, was found to be strongly correlated with the acid volatile sulfides content of the sediment. Overall, our results provide field validation of the hypothesis that Cr(VI) will not persist in sediments with excess acid volatile sulfides. Given the low concentrations of Cr(VI) in sediment and porewater, it appears unlikely that Cr in Baltimore Harbor sediments contributes appreciably to previously observed sediment toxicity.
Adsorption of arsenic to magnetite nanoparticles: Effect of particle concentration, pH, ionic strength, and temperature
Authors: Shipley Heather J. , Yean Sujin , Kan Amy T. , Tomson Mason B. 
Published: October 2008

Abstract
Little work has been conducted on the adsorption of arsenic to the mixed iron [Fe(II)/(III)] oxide magnetite and the effect that environmental parameters, such as pH, ionic strength, and temperature, have on adsorption. Magnetite nanoparticles are unique because of their affinity for both arsenate and arsenite and increased adsorption capacity from their bulk counterparts. This article shows the effect of various magnetite nanoparticle concentrations on arsenic adsorption kinetics. The adsorption data show the ability of the magnetite nanoparticles to remove arsenate and arsenite from solution in both synthetic and natural waters, and the data fit a first-order rate equation. Because of the increased surface area of these particles, less than 1 g/L of magnetite nanoparticles was needed. The results suggest that arsenic adsorption to the nanoparticles was not significantly affected by the pH, ionic strength and temperature in the ranges tested, which are typical of most potable water sources.
Addressing arsenic bioaccessibility in ecological risk assessment: A novel approach to avoid overestimating risk
Authors: Ollson Christopher A. , Koch Iris , Smith Paula , Knopper Loren D. , Hough Chris , Reimer Ken J. 
Published: October 2008

Abstract
The risk of arsenic exposure to deer mice (Peromyscus maniculatus) living in areas of naturally and anthropogenically elevated arsenic levels was determined using three separate calculations of arsenic daily intake: Estimated daily intake (EDI), bioaccessible EDI (BEDI), and actual daily intake (ADI). The present work is of particular interest, because the risk assessments were determined for animals naturally exposed to arsenic. Gastric fluid extraction was used to obtain bioaccessibility data for soil and plant samples collected from three study sites (background, mine forest, and tailings) in Yellowknife (NT, Canada). Calculations using the EDI indicated that deer mice living in tailings habitat (average soil arsenic concentration, 1,740 ± 2,240 μg/g) should have been experiencing serious health effects as a result of their exposure to arsenic. Using BEDI and ADI in the risk assessment calculation, however, resulted in an order-of-magnitude decrease in calculated risk. In addition, results calculated using the BEDI and ADI were not significantly different, suggesting that using bioaccessibility provides a more realistic estimate of potential risk. The present results provide evidence that the use of EDI in traditional risk assessments may seriously overestimate the actual risk, which in some instances may result in expensive and unnecessary clean-up measures.
Development of negligible depletion hollow fiber–protected liquid-phase microextraction for sensing freely dissolved triazines
Authors: Hu Xialin , Liu Jingfu , Jönsson Jan Å. , Jiang Guibin 
Published: October 2008

Abstract
A new sampling method, termed negligible depletion hollow fiber–protected liquid-phase microextraction, was developed for sensing the freely dissolved concentration (Cfree) and evaluating the availability of atrazine (ATR), desethyl atrazine (DEA), and simazine (SIM) in water. The sampling device was prepared by impregnating 1-octanol to both the pores and the lumen of a piece of polypropylene microporous hollow fiber membrane. After equilibrium and negligible depletion extraction, the 1-octanol in the lumen of the hollow fiber (10 μl) was collected for determination of triazines. Determination of Cfree and the distribution coefficient to 1-octanol (DOW) can be performed with this technique. A wide linear working range (1–200 μg/L) and low detection limits (0.1–1 μg/L) were obtained for triazines. Measured log DOW values of DEA (1.44 ± 0.04), SIM (2.06 ± 0.06), and ATR (2.33 ± 0.05) agreed well with those reported in the literature. The measured DOW values were independent of the chemical concentration and sample pH (pH 3–10) and negligibly affected by the sample salinity (0–500 mM), suggesting that environmentally relevant pH and salinity have no significant effects on the availability of triazines. Although a slight (≤31%) increase of Cfree was observed, one-way analysis of variance indicated the Cfree of triazines were not significantly affected by the presence of Aldrich humic acid, Acros humic acid, and bovine albumin V (dissolved organic carbon [DOC], 0–100 mg/L). From 3 to 36% of the spiked triazines, however, were found to associate with the dissolved organic matter (DOM) in surface-water samples (DOC, 32.0–61.9 mg/L), suggesting the origin of the DOM is a key parameter in determining its association with and, thus, the availability of triazines.
Enantioselectivity in the immunotoxicity of the insecticide acetofenate in an in vitro model
Authors: Zhao Meirong , Liu Weiping 
Published: October 2008

Abstract
Chiral pesticides with an asymmetrical center in their molecular structures possess enantioselectivity, not only in their pesticidal activities toward targeted organisms but also in toxicities to nontargeted organisms. Despite the fact that chiral pesticides deserve particular attention because of their ubiquitous presence in living and working environments, there has been limited research into their enantioselectivity in chronic toxicity. The immunotoxicity of chiral pesticides with respect to enantioselectivity has not been studied before. In this study, the role of enantioselectivity in the immunotoxicity of acetofenate (AF), an organochlorine insecticide, was investigated in an in vitro macrophage cell line model. Results of the cytotoxicity assay showed a clear dose-dependent growth inhibition effect of AF with enantioselectivity on RAW264.7 cells. S-(+)-AF was clearly more toxic to macrophages than R-(−)-AF and rac-AF. This work also demonstrated that S-(+)-AF possesses the strongest effects in induction of intracellular reactive oxygen species, DNA damage, and upregulation of p53 gene expression. These results, for the first time, show stark selectivity between enantiomers in their ability to induce macrophage-involved immunotoxicity of AF. These results suggest that assessment of the environmental safety and health risk of chiral contaminants should consider the role of enantioselectivity in immunotoxicity. In addition, our study will improve the knowledge of the role of enantioselectivity in immunotoxicity of chiral contaminants.
Disposition of perfluorinated acid isomers in sprague-dawley rats; Part 2: Subchronic dose
Authors: De Silva Amila O. , Benskin Jonathan P. , Martin Leah J. , Arsenault Gilles , McCrindle Robert , Riddell Nicole , Martin Jonathan W. , Mabury Scott A. 
Published: October 2008

Abstract
Two major industrial synthetic pathways have been used to produce perfluorinated acids (PFAs) or their precursors: Telomerization and electrochemical fluorination (ECF). Products of telomer and ECF origin can be distinguished by structural isomer profiles. A mixture of linear and branched perfluoroalkyl isomers is associated with ECF. Telomer products characteristically consist of a single perfluoroalkyl geometry, typically linear. In biota, it is unclear if the isomer profile is conserved relative to the exposure medium and hence whether PFA isomer profiles in organisms are useful for distinguishing environmental PFA sources. A companion study suggested isomer-specific disposition following a single oral gavage exposure to rats. To confirm these findings under a more realistic subchronic feeding scenario, male and female rats were administered PFA isomers by diet for 12 weeks, followed by a 12-week depuration period. The diet contained 500 ng/g each of ECF perfluorooctanoate (PFOA, ∼80% n-PFOA), ECF perfluorooctane sulfonate (PFOS, ∼70% n-PFOS), and linear and isopropyl perfluorononanoate (n- and iso-PFNA). Blood sampling during the exposure phase revealed preferential accumulation of n-PFOA and n-PFNA compared to most branched isomers. Female rats depurated all isomers faster than males. Both sexes eliminated most branched perfluorocarboxylate isomers more rapidly than the n-isomer. Elimination rates of the major branched PFOS isomers were not statistically different from n-PFOS. Two minor isomers of ECF PFOA and one branched PFOS isomer had longer elimination half-lives than the n-isomers. Although extrapolation of these pharmacokinetics trends in rats to humans and wildlife requires careful consideration of dosage level and species-specific physiology, cumulative evidence suggests that perfluorocarboxylate isomer profiles in biota may not be suitable for quantifying the relative contributions of telomer and ECF sources.
Career choice motivations of medical students and some characteristics of the decision process in Hungary
Authors: Molnár Regina , Nyári Tibor , Hazag Anikó , Csinády Adriána , Molnár Péter 
Published: October 2008

Abstract
The changed circumstances of medical work, raises the question of how socio-economic changes over the last few decades has affected the professional socialisation of medical students. This paper explores the career choice motivations of medical students, as well as some characteristics of the process of making that choice and their effects on professional socialisation. The study was carried out with a self-administered questionnaire with 503 students in general medicine, randomly selected from two Hungarian Medical Schools. More than half of the students contemplated becoming a doctor as early as in their childhood. Their final decision was typically made in high school. Significant differences can be demonstrated in professional socialisation between those individuals identifying with the profession in early childhood and others turning to the profession later. Altruistic motivations were the most significant career choice reasons. In conclusions, the medical career choice must have deeper roots, yielding to an evolutionary psychological analysis as well, one aspect of which is altruism.
Diastolic blood pressure cut-off predicts major cerebrovascular events after minor ischaemic stroke: a post-hoc modelling study
Authors: Atanassova Penka , Chalakova Nedka , Dimitrov Borislav 
Published: October 2008

Abstract
Only few follow-up studies have studied in detail the role of most important risk factors, but no reports were found on critical values (cut-offs) for such factors in prospectively predicting cerebrovascular events (CVE) in patients with minor ischaemic stroke (MIS). Estimates of predictive importance of such cut-offs may better inform and contribute to optimize treatment. This was a post-hoc modelling study with unique data from Bulgaria on 54 consecutive patients with MIS, aged ł 40, followed for 12 months for nonfatal or fatal CV events. A set of routine clinical demographic and known risk factors (SBP, DBP, HDL cholesterol, etc.) were explored using univariate statistics and multivariate regression models to identify the most important independent predictors of secondary CVE. An artificial neural network (ANN) model, irrespective of usual statistical constraints, also confirmed the specific role and importance of identified predictors. A receiver operating characteristics (ROC) curve and stratified survival analyses were used to define the best cut-off of most important predictors and validate the final model. During follow-up period of 11.1±2.4 months, 8 secondary CV events (14.8%) were observed only in males with MIS at the 5.8±2.7 months mark. No difference in age of patients with CV event (61.1±12.6 years) vs. those without (62.1±9.6 years) was found (p>0.05). The one-year risk for CVE was.15% (95%CI 7.1, 27.7%). The two most important risk factors in patients with versus without CV events were acute MIS onset (62.5 vs. 13.0%) and mean DBP at day 30 post-MIS (101.3±9.9 vs. 92.3±10.8 mmHg), with a relative importance by ANN of 20.92 versus 15.9 points, respectively. At multivariate logistic analysis only MIS onset and DBP were independently associated with the risk for secondary CVE (79.6% model accuracy, p
model=0.0015). An increase of DBP with 1 mmHg was associated with 8% higher risk of CVE [adjusted OR=1.08 (95%Cl 1.004, 1.158)]. With this method, a novel cut-off predictive DBP value of 95 mmHg (ROCAUC=0.79, 95%Cl 0.60, 0.99, p=0.009) for CV events in patients with MIS has been found. In conclusions the new DBP cut-off (sensitivity >87%, specificity >69%) clearly discriminated between absence and presence of secondary CVE as also confirmed by stratified survival analysis (7 vs. 1 events, plog-rank =0.0103). This cut-off may be applied to better precisely evaluate and define, as earlier as possible, MIS patients at increased risk of secondary CV events.