bluuebunny/crossref_metadata_2025_split huggingface dataset:
Androgens and energy allocation: Quasi‐experimental evidence for effects of influenza vaccination on men's testosterone
Authors: Simmons Zachary L. , Roney James R. 
Published: October 2008

AbstractAndrogens are proposed to allocate finite energetic resources away from immune function and toward anabolic processes related to reproductive effort. In situations of pathogen exposure, the significant energetic demands associated with mounting an immune response are expected to produce a decrease in androgen levels and commensurate redistribution of energy. We tested the hypothesis that even the mild immune challenge associated with vaccination may cause a decline in men's testosterone. As predicted, men who received an influenza vaccination exhibited a more negative change in testosterone over a 2‐week period than did men in a nonequivalent control group who were not vaccinated. These results suggest that men's androgen concentrations may be finely calibrated to trade‐offs between the energetic demands of immune responses and other life history problems. Am. J. Hum. Biol., 2009. © 2008 Wiley‐Liss, Inc.
Demographic, clinical and occupational characteristics associated with early onset of delivery: Findings from the duke health and safety surveillance system, 2001–2004
Authors: Schoenfisch Ashley L. , Dement John M. , Rodríguez‐Acosta Rosa L. 
Published: October 2008

AbstractBackgroundThis cross‐sectional study explores associations between preterm delivery and demographic, clinical and occupational characteristics of women employed within a university and health system.MethodsA comprehensive surveillance system linking individual‐level data from Human Resources, medical insurance claims and a job‐exposure matrix was used to identify women with a single live birth between 2001 and 2004 and describe maternal characteristics during pregnancy.ResultsPreterm delivery occurred in 7.1% (n = 74) of the 1,040 women, a lower preterm delivery prevalence than observed in the general U.S. population. Nearly all (>99.5%) women utilized prenatal care services. Prevalence of preterm delivery was highest for inpatient nurses, nurses' aides and office staff. In multivariate analyses, preterm delivery was positively associated with several clinical conditions: placenta previa, diabetes and cardiovascular disorder/disease.ConclusionsWe observed associations between preterm delivery and several previously indicated clinical conditions. Further study of the effect of job characteristics on preterm delivery is warranted. Am. J. Ind. Med. 51:911–922, 2008. © 2008 Wiley‐Liss, Inc.
Work‐related non‐fatal injuries among foreign‐born and US‐born workers: Findings from the U.S. National Health Interview Survey, 1997–2005
Authors: Zhang Xiaofei , Yu Songlin , Wheeler Krista , Kelleher Kelly , Stallones Lorann , Xiang Huiyun 
Published: October 2008

AbstractBackgroundMillions of foreign‐born workers are employed in the US. Population‐based surveys have value in describing the non‐fatal work‐related injuries that these workers suffer.MethodsUsing data from the 1997–2005 National Health Interview Survey, we compared the rates of non‐fatal work‐related injuries among foreign‐born and US‐born adult workers. Logistic regression was used to produce work‐related injury odds ratios (ORs) and 95% confidence intervals (95% CI) by nativity and years of residence while controlling for sex, age, race/ethnicity, education, poverty, family size, insurance status, delayed medical care, and alcohol use. Industry‐specific rates were also compared.ResultsForeign‐born workers reported a lower rate of work‐related injuries than US‐born workers, 50 per 10,000 foreign‐born workers versus 89 per 10,000 US‐born workers (P < 0.01). After controlling for confounding variables, the OR of work‐related injuries for foreign‐born workers as compared to US‐born workers was 0.50 (95% CI = 0.38–0.66). The construction, agriculture/forestry and fisheries, and manufacturing industries had the highest work‐related injury rates for both groups of workers.ConclusionsForeign‐born workers had a lower overall rate of work‐related injury when compared to US‐born workers. Both US‐born and foreign‐born workers face significant injury risks, especially in certain industries. Interventions tailored with ethnic and cultural differences in mind are still warranted. Am. J. Ind. Med. 52:25–36, 2009. © 2008 Wiley‐Liss, Inc.
Impact of implementing the washington state ergonomics rule on employer reported risk factors and hazard reduction activity
Authors: Foley Michael , Silverstein Barbara , Polissar Nayak , Neradilek Blazej 
Published: October 2008

AbstractBackgroundIn Washington State an ergonomics rule was adopted in 2000 that focused on primary prevention. The implementation process followed a 6‐year phase‐in schedule where employers came into compliance based upon their size and industry. In late 2003 the rule was repealed by an industry‐funded voter initiative. Evaluating the implementation of this rule offers a unique opportunity to observe the general deterrent effect of a new public health regulation and to study how employers and workers responded to new requirements.MethodsWeighted survey regression methods were used to analyze the results from three employer surveys covering more than 5,000 workplaces administered in 2001, 2003, and 2005. These were compared to a baseline employer survey conducted in 1998 before the rule was promulgated. Questions covered the following topics: WMSDs experienced at the workplace; levels of employee exposure to musculoskeletal hazards; steps being taken, if any, to address these hazards; results of these steps; and sources of ergonomic information/assistance used.ResultsFrom 1998 to 2003 there was a reduction in reported exposures among workplaces in the highest hazard industries. Following the rule's repeal, however, hazard exposures increased. While more workplaces reported taking steps to reduce exposures between 1998 and 2001, this gain was reversed in 2003 and 2005. Employers who took steps reported positive results in injury and absenteeism reduction. Large workplaces in the high hazard industries were more active in taking steps and used a wide variety of resources to address ergonomics issues. Small employers relied more on trade associations and the state. Am. J. Ind. Med. 52:1–16, 2009. © 2008 Wiley‐Liss, Inc.
Effect of protective filters on fire fighter respiratory health: field validation during prescribed burns
Authors: De Vos Annemarie J.B.M. , Cook Angus , Devine Brian , Thompson Philip J. , Weinstein Philip 
Published: October 2008

AbstractBackgroundBushfire smoke contains a range of air toxics. To prevent inhalation of these toxics, fire fighters use respiratory equipment. Yet, little is known about the effectiveness of the equipment on the fire ground. Experimental trials in a smoke chamber demonstrated that, the particulate/organic vapor/formaldehyde (POVF) filter performed best under simulated conditions. This article reports on the field validation trials during prescribed burns in Western Australia.MethodsSixty‐seven career fire fighters from the Fire and Emergency Services Authority of Western Australia were allocated one of the three types of filters. Spirometry, oximetry, self‐reported symptom, and personal air sampling data were collected before, during and after exposure to bushfire smoke from prescribed burns.ResultsDeclines in FEV1 and SaO2 were demonstrated after 60 and 120 min exposure. A significant higher number of participants in the P filter group reported increases in respiratory symptoms after the exposure. Air sampling inside the respirators demonstrated formaldehyde levels significantly higher in the P filter group compared to the POV and the POVF filter group.ConclusionsThe field validation trials during prescribed burns supported the findings from the controlled exposure trials in the smoke chamber. Testing the effectiveness of three types of different filters under bushfire smoke conditions in the field for up to 2 hr demonstrated that the P filter is ineffective in filtering out respiratory irritants. The performance of the POV and the POVF filter appears to be equally effective after 2 hr bushfire smoke exposure in the field. Am. J. Ind. Med. 52:76–87, 2009. © 2008 Wiley‐Liss, Inc.
Synthesis and characteristics of photoactive‐hydrogenated rosin epoxy methacrylate for pressure sensitive adhesives
Authors: Do Hyun‐Sung , Park Jin‐Hee , Kim Hyun‐Joong 
Published: October 2008

AbstractHydrogenated rosin epoxy methacrylate (HREM), based on hydrogenated rosin and glycidyl methacrylate (GMA), was synthesized for use as an advanced tackifier in the UV‐crosslinking pressure sensitive adhesives (PSAs) system. The HREM, as a tackifier, contained UV‐curing sites; thus, allowed photopolymerization to occur by UV irradiation. This UV‐curable tackifier, HREM, can improve the curing rate and adhesion performance of UV‐crosslinking PSAs. The characteristics of HREM were analyzed by GPC and DSC and its synthetic mechanism studied using FTIR and 1H NMR; the characteristic peaks of hydrogenated rosin and GMA vanished, but new peaks for HREM appeared. The PDI and the Tg by DSC were 1 and −25.6°C, respectively. The photopolymerization of HREM was studied using photo‐DSC. Heat flow was observed during UV irradiation, and the curing rate and conversion both increased with rising photoinitiator content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Membrane formation of poly(vinylidene fluoride)/poly(methyl methacrylate)/diluents via thermally induced phase separation
Authors: Ma Wenzhong , Chen Shuangjun , Zhang Jun , Wang Xiaolin , Miao Wenhu 
Published: October 2008

AbstractThe role of the single diluents and mixed diluents on the poly (vinylidene fluoride) (PVDF)/poly(methyl methacrylate) (PMMA) blend membranes via thermally induced phase separation (TIPS) process was investigated. The crystallization behaviors of PVDF in the diluted samples were examined by differential scanning calorimetry. The melting and crystallization temperatures of those diluted PVDF blend were decreased with the enhanced interactions between polymer chains and diluent molecules. The crystallinity of PVDF in the diluent was always higher than that obtained in PVDF blend sample. This can be explained by the dilution effects, which increased the average spatial separation distances between crystallizable chains. Thus, the PVDF crystallization was favored. Additionally, solid‐liquid (S‐L) phase separation occurred in the quenched samples. Illustrated by scanning electron microscopy, inter‐ and intraspherulitic voids were formed in the ultimate membranes, which related to the polymer/diluent interactions, the kinetics of crystallization and diluent rejection from the growing crystal. The porosity of the PVDF blend membranes obtained from the mixed diluents was higher than those obtained from the single diluent samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Swelling properties of copolymers of styrene and divinylbenzene containing sulfonic and carboxylic acid groups
Authors: Chee Swee Yong , Gan Seng Neon 
Published: October 2008

AbstractCopolymers of styrene, divinylbenzene, and acrylic acid that have undergone sulfonation exhibited good water absorbency properties. Removal of the lower molecular weight fraction in the surface region of the copolymer particles by toluene extraction before sulfonation has further increased the water swelling capacity of the sulfonated copolymers. The extent of swelling of the UV‐irradiated copolymer could be related to the ratio of divinylbenzene to styrene. The less crosslinked copolymers were shown to absorb more water. The incorporation of more carboxylate groups in the copolymer could further increase its swelling capacity. Without UV irradiation, the carboxylate containing copolymer was found to absorb more water than the sulfonated copolymer. UV irradiation has induced more effective crosslinking in the carboxylate containing copolymer, hence impairing its water absorbency. By replacing styrene and divinylbenzene partially with butyl acrylate, whereby the amount of crosslinking was reduced, the copolymer was able to absorb water 110 times of its dry weight. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Multifractality in the copolymerization of Bis‐GMA/TEGDMA by pulsed photoacoustics
Authors: Navarrete M. , Pineda J. , Vera‐Graziano R. 
Published: October 2008

AbstractFractal development during polymerization of a dimethacrylate system (Bis‐GMA/TEGDMA) has been studied through the analysis of time series obtained sequentially by pulsed photoacoustics. The photoacoustic signals as obtained in situ during photopolymerization of Bis‐GMA/TEDGMA were analyzed by rescaled range analysis, dispersion analysis, and detrended fluctuation analysis methods. The analysis reveals the presence of more than one scaling parameter and, therefore, belongs to a complex process known as multifractal. The evolution of fractality during photopolymerization was compared under equivalent conditions with the chemical conversion (of dimethacrylate double bonds) as a function of time, as monitor by infrared spectroscopy. This kinetic study was also used to correlate the fractal nature of the dimethacrylate reaction system with the condensed‐state transitions emerging during the photochemical reaction. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Crystallization behavior of elastomeric block copolymers: Thermoplastic polyurethane and polyether‐block‐amide
Authors: Begenir Asli , Michielsen Stephen , Pourdeyhimi Behnam 
Published: October 2008

AbstractThe isothermal crystallization kinetics of melt‐blown webs produced from a series of elastomeric block copolymers was studied through differential scanning calorimetry (DSC). Three hardness grades were selected for a polyester and a polyether Elastollan® thermoplastic polyurethane and Pebax® polyether‐block‐amide copolymers. The Avrami crystallization kinetics parameters, k and n, were derived from two different methods: (1) traditional Avrami model and (2) derivative of the Avrami model proposed by Kurajica et al. (Croat Chem Acta 2002, 75, 693). The kinetic parameters from both models were consistent and showed good correlation. For all polymer types and hardness grades, crystallization kinetics were interpreted with the derivative model (Kurijica et al.) since it could be directly fitted to untransformed DSC isothermal crystallization data, and thus reduces the errors involved in Avrami analysis. The values of the Avrami exponent, n ranged between 2.59 and 3.41, indicating similar nucleation and growth mechanisms. These n values and morphological observations indicate that crystallization occurs in these copolymers in three dimensions from pre‐existing nuclei and the crystals grow under isothermal conditions. This suggests that, in these elastomeric copolymers, crystallization of the hard segments drives microphase separation into crystalline and amorphous regions rather than formation of hard and soft domains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Nonisothermal crystallization kinetics of nucleated poly(ethylene terephthalate)
Authors: Deshpande V. D. , Jape Sandeep 
Published: October 2008

AbstractStudies of the nonisothermal crystallization kinetics of poly(ethylene terephthalate) nucleated with anhydrous sodium acetate were carried out. The chemical nucleating effect was investigated and confirmed with Fourier transform infrared and intrinsic viscosity measurements. The Avrami, Ozawa, and Liu models were used to describe the crystallization process. The rates of crystallization, which initially increased, decreased at higher loadings of the additive. The activation energy, calculated with Kissinger's method, was lower for nucleated samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Sulfonated poly(ether ether ketone)/epoxy/phenol novolac blend proton‐exchange membranes with low methanol permeability
Authors: Fu Tiezhu , Zhong Shuangling , Cui Zhiming , Zhao Chengji , Shi Yuhua , Yu Wenzhi , Na Hui , Xing Wei 
Published: October 2008

AbstractA crosslinked epoxy [4,4′‐diglycidyl‐(3,3′,5,5′‐tetramethylbiphenyl) epoxy resin (TMBP)], cured by phenol novolac (PN), was introduced into a sulfonated poly(ether ether ketone) (SPEEK) membrane (ion‐exchange capacity = 2.0 mequiv/g) with a casting‐solution, evaporation, and heating crosslinking method to improve the mechanical properties, dimensional stability, water retention, and methanol resistance. By Fourier transform infrared analysis, the interactions between the sulfonic acid groups and hydroxyl groups in the blend membranes were confirmed. The microstructure and morphology of the blend membranes were investigated with atomic force microscopy. As expected, the blend membranes showed excellent mechanical properties, good thermal properties (thermal stability above 200°C), lower swelling ratios (1.4% at 25°C and 7.0% at 80°C), higher water retention (water diffusion coefficient = 9.8 × 10−6 cm2/s), and a lower methanol permeability coefficient (3.6 × 10−8 cm2/s) than the pristine SPEEK membrane. Although the proton conductivity of the blend membranes decreased, a higher selectivity (ratio of the proton conductivity to the methanol permeability) was obtained than that of the pristine SPEEK membrane. The results showed that the SPEEK/TMBP/PN blend membranes could have potential use as proton‐exchange membranes in direct methanol fuel cells. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyurethane‐solid wood composites prepared with various catalysts. I. Mechanical properties and dimensional stabilities
Authors: Gao Zhenhua , Wu Di , Su Wenqiang , Ding Xiaoling 
Published: October 2008

AbstractPolyurethane (PU)‐solid wood composites were prepared by impregnating PU prepolymer into low‐density fast‐growing poplar solid wood and controlling the prepolymer cured or foamed within wood voids in the presence of the catalysts triethanolamine (TEA), diethylenetriamine (DETA), triethylenediamine (TEDA), and N‐methyl morpholine (NMM), respectively. A scanning electron microscope (SEM) was used to observe the morphologies of the cured PU resin and the wood voids, and the effects of catalyst species on the mechanical properties and dimensional stabilities of PU‐wood composites were evaluated. The results indicated that the PU prepolymer cured in the presence of various catalysts resulted in different morphologies and distributions within wood voids, and therefore led to various mechanical properties and dimensional stabilities of the PU‐wood composites. Because of the fact that wood cell walls in the surface layer had apparently collapsed in the presence of catalyst DETA and therefore the wood was densified, the PU‐wood composite prepared with DETA had the best mechanical properties and dimensional stabilities. The PU prepolymer was well impregnated and evenly foamed within the wood in the presence of catalyst NMM, giving the PU‐wood composite prepared with NMM much better dimensional stability as the foamed PU blocked the water transfer between the cells. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Porous microspheres, copolymers of bis[4‐(2‐hydroxy‐ 3‐methacryloyloxypropoxy)phenyl]sulfide, and divinylbenzene as stationary phase for HPLC
Authors: Podkościelna Beata , Bartnicki Andrzej , Gawdzik Barbara 
Published: October 2008

AbstractSynthesis of highly crosslinked methacrylate copolymers of in form of microspheres is presented. They are prepared from tetrafunctional methacrylate derivative of bis(4‐hydroxyphenyl)sulfide, bis[4‐(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]sulfide (BES‐DM), and divinylbenzene (DVB). In chemical structure of these copolymers exhibit hydroxyl and ester groups of hydrophilic nature. Additionally, copolymer contains sulfur atoms coming from BES‐DM monomer. Porous structure of the copolymers in the dry and wet state was studied. Microspheres possessing the largest pore volume and specific surface area were subjected to chromatographic investigations. The results show that polar functional groups existing in the chemical structure of the studied microspheres have influence on reversed‐phase HPLC retention mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Self assembled hydrophobic nanoclusters of poly(methyl methacrylate) embedded into polyvinyl alcohol based hydrophilic matrix: Preparation and water sorption study
Authors: Shukla Sandeep Kumar , Shaikh A. Wasif , Gunari Nikhil , Bajpai A. K. , Kulkarni R. A. 
Published: October 2008

AbstractHydrophilic matrices containing nanosized clusters of hydrophilic moieties have demonstrated potential applications in biomedical field. A novel hydrogel containing nanosized domains (20–35 nm) of hydrophobic moieties of poly(methyl methacrylate) (PMMA) was prepared by grafting crosslinked poly(acrylic acid‐co‐methyl methacrylate) chains onto polyvinyl alcohol (PVA) backbone using an efficient redox system. The graft copolymerization process was investigated to observe the influence of gel components on the kinetic parameters of grafting such as rate of grafting (Rg), grafting yield (Gy) and grafting efficiency (Ge). The prepared graft nanohydrogel was evaluated for its water sorption potential under varying chemical composition of the gel and changing pH, temperature, and ionic strength of the swelling bath. The swelling process was also examined mechanistically and diffusion constants (D) of water molecules through the swellable nanohydrogel were also evaluated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A study of the rheological behavior of high‐temperature polymer electrolyte membrane solutions
Authors: Harris Tequila A. L. , Walczyk Daniel 
Published: October 2008

AbstractThe viscosity behavior of various compositions of polymer electrolyte membrane solutions, which are later hydrolyzed into proton conducting membrane film for fuel cells, is characterized. Using the Carreau‐Yasuda model and time–temperature superposition, an empirical model relating the viscosity as a function of temperature and shear strain rate has been developed for several membrane solution compositions. It is observed that the viscosity of the non‐Newtonian membrane has a strong correlation to the membrane's inherent viscosity (a property determined during membrane synthesis). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Thermal and mechanical behavior of flexible polyurethane‐molded plastic films and water‐blown foams with epoxidized soybean oil
Authors: Tu Yuan‐Chan , Suppes Galen J. , Hsieh Fu‐Hung 
Published: October 2008

AbstractWater‐blown flexible polyurethane foams and molded plastic films were made by replacing 0 to 50% of Voranol® 4701 in the B‐side of foam and plastic film formulation by epoxidized soybean oil (ESBO). Physical properties of foams including density, 50% compression force deflection (CFD), 50% constant deflection compression (CDC), and resilience were determined. A dynamic mechanical spectrometer (DMS) and a differential scanning calorimeter (DSC) were used to characterize the hard segment (HS) and soft segment (SS) ratio and thermal properties of plastic. Various functional groups in both flexible polyurethane foam and plastic film were characterized using Fourier transform‐infrared spectroscopy with attenuated total reflectance (FTIR‐ATR). When increasing the ESBO content, both density and 50% CFD of water‐blown polyurethane foams decreased first, then increased. On the other hand, the 50% CDC and resilience of foams showed a sharp increase and decrease, respectively. When increasing the ESBO content, the peak of tan δ in DMS analysis and Δcp in DSC analysis of plastic films both decreased indicating the hard segment increased and the soft segment decreased in plastic film, respectively. The FTIR‐ATR results also show the hydrogen‐bonded urethane group increased in plastic films with increasing ESBO content. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009