bluuebunny/crossref_metadata_2025 huggingface dataset:
Parameter-induced uncertainty quantification of soil N2O, NO and CO2 emission from Höglwald spruce forest (Germany) using the LandscapeDNDC model
Authors: Rahn K.-H. , Werner C. , Kiese R. , Haas E. , Butterbach-Bahl K.
Published: April 2012

Abstract. Assessing the uncertainties of simulation results of ecological models is becoming of increasing importance, specifically if these models are used to estimate greenhouse gas emissions at site to regional/national levels. Four general sources of uncertainty effect the outcome of process-based models: (i) uncertainty of information used to initialise and drive the model, (ii) uncertainty of model parameters describing specific ecosystem processes, (iii) uncertainty of the model structure and (iv) accurateness of measurements (e.g. soil-atmosphere greenhouse gas exchange) which are used for model testing and development. The aim of our study was to assess the simulation uncertainty of the process-based biogeochemical model LandscapeDNDC. For this we set up a Bayesian framework using a Markov Chain Monte Carlo (MCMC) method, to estimate the joint model parameter distribution. Data for model testing, parameter estimation and uncertainty assessment were taken from observations of soil fluxes of nitrous oxide (N2O), nitric oxide (NO), and carbon dioxide (CO2) as observed over a 10 yr period at the spruce site of the Höglwald Forest, Germany. By running four independent Markov Chains in parallel with identical properties (except for the parameter start values), an objective criteria for chain convergence developed by Gelman et al. (2003) could be used. Our approach showed that by means of the joined parameter distribution, we were able not only to limit the parameter space and specify the probability of parameter values, but also to assess the complex dependencies among model parameters used for simulating soil C and N trace gas emissions. This helped to improve the understanding of the behaviour of the complex LandscapeDNDC model while simulating soil C and N turnover processes and associated C and N soil-atmosphere exchange. In a final step the parameter distribution of the most sensitive parameters determining soil-atmosphere C and N exchange were used to obtain the parameter-induced uncertainty of simulated N2O, NO and CO2 emissions. These were compared to observational data of the calibration set (6 yr) and an independent validation set of 4 yr. The comparison showed that most of the annual observed trace gas emissions were in the range of simulated values and were predicted with a high certainty (Residual mean squared error (RMSE) NO: 2.5 to 21.3 g N ha−1 d−1, N2O: 0.2 to 21.4 g N ha−1 d−1, CO2: 5.8 to 12.6 kg C ha−1 d−1). However, LandscapeDNDC simulations were sometimes limited to accurately predict observed seasonal variations in fluxes.
Model based on dimensional analysis for prediction of nitrogen and phosphorus concentration in the River Laborec
Authors: Zeleňáková M. , Čarnogurská M. , Šlezingr M. , Słyś D.
Published: April 2012

Abstract. The main aim of this paper is to develop a model for pollutant concentration prediction in a stream. The developed model that determines nitrogen and phosphorus concentrations in a river is based on a dimensional analysis. Applications of dimensional analysis to water quality modelling are presented, pointing out possibilities of applying this methodology in water quality research. We investigate how dimensional analysis can be applied to water quality modelling and which benefits it can bring to researchers in this area. The models were developed, calibrated and evaluated using measured data from the River Laborec in eastern Slovakia.
Transplantation of Co-Microencapsulated Hepatocytes and HUVECs for Treatment of Fulminant Hepatic Failure
Authors: Qiu Liyuan , Wang Jian , Wen Xinyu , Wang Haibin , Wang Yan , Lin Qiuxia , Du Zhiyan , Duan Cuimi , Wang Chunren , Wang Changyong
Published: April 2012

Purpose:

Microencapsulated hepatocytes might solve immunological rejection, broadening a new perspective for the treatment of fulminant hepatic failure (FHF). However, the transplantation of microcapsulated hepatocytes is limited by low cell viability Nevertheless, the co-microencapsulation of hepatocytes and human umbilical vein endothelial cells (HUVECs) may make the treatment of FHF more promising.

Methods:

We prepared the microcapsules using the high-voltage electrostatic droplet spray method, transplanted the empty microcapsules, isolated hepatocytes, microcapsulated hepatocytes, and co-microencapsulated hepatocytes and HUVEC intraperitoneally into rat models of FHF induced by D-aminogalactose (D-gal). After 1, 3, and 7 days, and 2, 3, and 4 weeks posttransplantation, we calculated the mortality and assessed alanine aminotransferase (ALT), aspartate aminotransferase (AST), and albumin (ALB) levels in the serum of the model; evaluated the integrality and recovery of microcapsules; and stained with hematoxylin and eosin (H&E) the recovered microcapsules as well as the liver of the FHF rats.

Results:

Hepatocyte-specific functions, including the levels of ALT, AST, and ALB in the serum of the co-microencapsulation group, were significantly better than those in the other groups (p<0.05) from 2 to 4 weeks after transplantation. Moreover, cotransplantation of the microencapsulated hepatocytes and HUVECs decreased the mortality rate of the FHF rats. The recovered microcapsules were intact, and recovery was up to 90%. H&E staining showed that the microencapsulated cells were still alive, and the liver tissues had started to recover after 4 weeks posttransplantation.

Conclusion:

The microcapsules have good biocompatibility and immunoprotection to protect the hepatocytes from immunological rejection. Cotransplantation of the microencapsulated hepatocytes and HUVECs could decrease mortality rates and improve liver function in FHF.
Telangiectatic Osteosarcoma
Authors: Sangle Nikhil A. , Layfield Lester J.
Published: April 2012

Osteosarcoma is one of the most common primary malignant bone tumors in children and adolescents. Telangiectatic osteosarcoma is an unusual variant of osteosarcoma, forming 3% to 10% of all osteosarcomas. Radiographically, these tumors appear as purely lytic destructive lesions located in the metaphyses of long bones. The location and x-ray appearance of telangiectatic osteosarcomas are reminiscent of an aneurysmal bone cyst and can test the acumen of a diagnostic radiologist. Distinguishing between the two entities microscopically can also be quite challenging. Telangiectatic osteosarcoma shows dilated blood-filled spaces lined or traversed by septa containing atypical stromal cells, with or without production of a lacelike osteoid matrix. This review highlights the diagnostic features of telangiectatic osteosarcoma and discusses differential diagnostic considerations, treatment options, and prognostic implications.
Comparison of Analytical and Clinical Performance of Three Methods for Detection of Clostridium difficile
Authors: LaSala P Rocco , Svensson Annika M. , Mohammad Amin A. , Perrotta Peter L.
Published: April 2012

Context.—Diagnostic laboratory testing for Clostridium difficile infection has undergone considerable and rapid evolution during the last decade. The ideal detection method(s), which should exhibit high analytical and clinical sensitivity and specificity, remains undefined.

Objective.—We sought to evaluate the analytical and clinical performance characteristics of three methods for the laboratory detection of C difficile.

Design.—This study used 114 consecutive stool samples to compare three methods of C difficile detection: an enzyme immunoassay (EIA) for toxins A/B, a lateral flow membrane immunoassay for glutamate dehydrogenase (GDH), and a qualitative real-time polymerase chain reaction (PCR) assay. Medical records of all patients having ≥1 positive test result were reviewed to estimate the clinical likelihood of C difficile infection.

Results.—Based upon laboratory result consensus values, analytical sensitivity was significantly higher for GDH (94%) and PCR (94%) assays than for toxin EIA (25%). Analytical specificity was significantly higher for PCR (100%) and EIA (100%) than for GDH assay (93%). In contrast, assay performance based upon clinical probability of C difficile infection suggested lower discriminatory power (ie, clinical specificity) of the more analytically sensitive methods.

Conclusions.—Higher rates of C difficile detection will be realized upon implementation of GDH assay and/or real-time PCR–based testing algorithms than by testing with EIA alone. Further study is required to elucidate potential downstream costs for higher detection rates.
Advances in Treatment of Lung Cancer With Targeted Therapy
Authors: Cagle Philip T. , Chirieac Lucian R.
Published: April 2012

Context.—Ongoing preclinical investigations and clinical trials involving new targeted therapies promise to improve survival for patients with lung cancer. Targeted therapeutic agents, based on genetic mutations and signaling pathways altered in lung cancer, have added significantly to our armamentarium for lung cancer treatment while minimizing drug toxicity. To date, 4 targeted therapies have been approved for treatment of lung cancer by the US Food and Drug Administration: gefitinib in 2002, erlotinib in 2003, bevacizumab in 2006, and crizotinib in 2011.

Objective.—To review targeted therapies in lung cancer, the molecular biomarkers that identify patients likely to benefit from these targeted therapies, the basic molecular biology principles, selected molecular diagnostic techniques, and pathologic features correlated with molecular abnormalities in lung cancer. To review new molecular abnormalities described in lung cancer that are predictive for response to novel promising targeted agents in various phases of clinical trials.

Data Sources.—Review of the literature covering the molecular abnormalities of lung cancer with a focus on the molecular diagnostics and targeted therapy. Special emphasis is placed on summarizing evolving technologies useful in the diagnosis and characterization of lung cancer.

Conclusions.—Molecular testing of lung cancer expands the expertise of the pathologist, who will identify the tumor markers that are predictive of sensitivity or resistance to various targeted therapies and allow patients with cancer to be selected for highly effective and less toxic therapies.
Persistent tracking and identification of regime‐switching systems with structural uncertainties: unmodeled dynamics, observation bias, and nonlinear model mismatch
Authors: Kan Shaobai , Yin George , Wang Le Yi
Published: April 2012

This work focuses on tracking and system identification of systems with regime‐switching parameters, which are modeled by a Markov process. It introduces a framework for persistent identification problems that encompass many typical system uncertainties, including parameter switching, stochastic observation disturbances, deterministic unmodeled dynamics, sensor observation bias, and nonlinear model mismatch. In accordance with the ‘frequency’ of the parameter switching process, we divide the problems into two classes. For fast‐switching systems, the switching parameters are stochastic processes modeled by irreducible and aperiodic Markov chains. Because accurately tracking real‐time parameters in such systems is not possible because of the uncertainty principles, the effect of parameter switching is evaluated on their average by the stationary distribution of the Markovian chain and estimated by the least squares algorithms. We derive upper and lower bounds on identification errors, which characterize how identification accuracy depends on the earlier uncertainty terms. When the system parameters switch their values infrequently in a probabilistic sense, their values can be tracked based on input/output observations. Stochastic approximation algorithms with adaptive step sizes are used for such systems. Simulation studies are carried out to demonstrate that slowly varying parameters could be tracked with reasonable accuracy.Copyright © 2012 John Wiley & Sons, Ltd.
Effect of Reaction Conditions on the Particle Morphology of Aqueous Dispersion of Poly(acrylamide‐acrylatedimethylaminoethyl methacrylate methyl chloride)
Authors: Hu Zunfu , Zhang Jun , Liu Juan , Wang Chuanxing , Wu Yumin
Published: April 2012

Amphoteric polyacrylamide was prepared by dispersion polymerization with acrylamide, dimethylaminoethyl methacrylate methyl chloride, and acrylate acid as monomers, ammonium sulfate (AS) aqueous solution as a reaction medium, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as a stabilizer, and 2,2′‐azobis(2‐amidinopropane) dihydrochloride as an initiator. The influence of particle morphology on AmPAM dispersion and other factors and polymerization were investigated. Three crucial factors responsible for particle morphology are the dispersant concentration, sodium chloride concentration, and ionic degree of terpolymer. The ammonium sulfate concentration had relatively less of an effect on particle morphology, but a suitable concentration was necessary to obtain a stable dispersion system. A higher concentration of PDMC could yield more uniform and spherical particles during dispersion polymerization. A small amount of sodium chloride can decrease particle size and dispersion viscosity. These four factors heavily influenced the viscosity of polymer dispersion, and they had a large effect on the intrinsic viscosity of AmPAM except for the AS and NaCl concentration. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 32: E212–E220, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21264
Polymers in industry: From guncotton to CO2 glass
Authors: Mascia Leno , Acierno Domenico
Published: April 2012

The origins of the commercial exploitation of synthetic polymers and the subsequent industrial developments are reviewed, and the main landmarks are highlighted, starting from the pioneering work on the nitration of cellulose in the 19th century and progressing through various advancements to the latest innovations. This includes the contribution made by many authorities, starting from Staudinger, as the founder of polymer science, to the most recent Nobel laureates in the field. The increased awareness for the need to capture CO2 from combustion gases has stimulated interests in the possibility of using polymerization methods as a route to produce useful solid products. The available theoretical arguments and experimental evidence are presented in relation to the feasibility of producing linear polymers, both as homopolymer and copolymers, placing emphasis on stability aspects and possible uses of the products. The various claims on the possibility of opening both double bonds of molecular CO2 to produce stable networks are also analyzed. Arguments in support of the possibilities of producing mixed CO2–SiO2 glasses are provided, and the expected properties of the resulting solids are discussed. Suggestions are made for the possible utilization of such products. © 2012 Wiley Periodicals, Inc. Adv Polym Techn 31: 179–192, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/adv.21275
Multi‐Length‐Scale Morphologies in PCPDTBT/PCBM Bulk‐Heterojunction Solar Cells
Authors: Gu Yu , Wang Cheng , Russell Thomas P.
Published: April 2012

Additives are known to improve the performance of organic photovoltaic devices based on mixtures of a low bandgap polymer, poly[2,6‐(4,4‐bis(2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]‐dithiophene)‐alt‐4,7‐(2,1,3‐benzothiadiazole)] (PCPDTBT) and [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM). The evolution of the morphology during the evaporation of the mixed solvent, which comprises additive and chlorobenzene (CB), is investigated by in‐situ grazing incidence X‐ray scattering, providing insight into the key role the additive plays in developing a multi‐length‐scale morphology. Provided the additive has a higher vapor pressure and a selective solubility for PCBM, as the host solvent (CB) evaporates, the mixture of the primary solvent and additive becomes less favorable for the PCPDTBT, while completely solubilizing the PCBM. During this process, the PCPDTBT first crystallizes into fibrils and then the PCBM, along with the remaining PCPDTBT, is deposited, forming a phase‐separated morphology comprising domains of pure, crystalline PCPDTBT fibrils and another domain that is a PCBM‐rich mixture with amorphous PCPDTBT. X‐ray/neutron scattering and diffraction methods, in combination with UV–vis absorption spectroscopy and transmission electron microscopy, are used to determine the crystallinity and phase separation of the resultant PCPDTBT/PCBM thin films processed with or without additives. Additional thermal annealing is carried out and found to change the packing of the PCPDTBT. The two factors, degree of crystallinity and degree of phase separation, control the multi‐length‐scale morphology of the thin films and significantly influence device performance.
Association between perceived union connection and upper body musculoskeletal pains among unionized construction apprentices
Authors: Kim Seung‐Sup , Perry Melissa J. , Okechukwu Cassandra A.
Published: April 2012

Background

Several studies show varying associations between unionization and workers' health and well‐being. This study investigated the association between individual worker's perceived union connection and musculoskeletal pains (MSPs).

Methods

We conducted a cross‐sectional survey of 1,757 unionized construction apprentices. Perceived union connection is a psychosocial scale measured by six questions that assessed individual worker's connection to their union (range 10–24) at unionized workplaces. We measured the prevalence of four MSPs (neck, shoulder, arm, and back pain) and difficulty in daily home activities, job activities, and sleeping caused by each of the four MSPs.

Results

We found that a one score increase in perceived union connection was associated with 5% decreased odds of reporting neck pain (OR: 0.95, 95% CI: 0.91–1.00) and back pain (OR: 0.95, 95% CI: 0.91–0.99) after adjusting for confounders including self‐reported ergonomic strain. We also found significant associations between perceived union connection and MSPs causing difficulty in daily activities. For a one score increase in perceived union connection, the odds of reporting back pain causing difficulty in home activities, job activities, and sleeping was 9% (95% CI: 0.87–0.96), 8% (95% CI: 0.88–0.96), and 7% (95% CI: 0.89–0.98) lower, respectively.

Conclusions

Although our findings are limited by the cross‐sectional nature of the data, these results suggest that workers' perceived union connection can vary even within unionized workplaces, and it may be associated with the prevalence of MSPs and MSPs causing difficulty in daily activities. Am. J. Ind. Med. 56:189–196, 2013. © 2011 Wiley Periodicals, Inc.
The association between nonstandard work and occupational injury in Korea
Authors: Im Hyoung‐June , Oh Dae‐gyu , Ju Young‐Su , Kwon Young‐Jun , Jang Tae‐Won , Yim Jun
Published: April 2012

Background

The number of workers who died due to occupational injury in Korea as of 2007 was 1,383. The aim of this study was to identify whether there were any differences in the risk of occupational injury between nonstandard workers (temporary workers and/or subcontract workers) and regular workers.

Methods

1,576 injured workers, selected from National Health Insurance and National Workers' Compensation Insurance, were interviewed via telephone survey using standardized questionnaires in 2007. The control group was 1,500 workers matched for age, gender, and severity of injury. A multivariate logistic regression model was used to analyze the association between the type of nonstandard work and occupational injury.

Results

Nonstandard temporary workers were more likely to be injured than regular workers even if other related factors of occupational injury were statistically adjusted (adjusted odds ratio, OR 2.87, 95% confidence interval 2.37–3.49).

Conclusions

The reason why the risks of nonstandard workers are higher than those of regular workers is that nonstandard workers are placed in poor working conditions. Am. J. Ind. Med. 55:876–883, 2012. © 2012 Wiley Periodicals, Inc.
Work safety climate and safety practices among immigrant Latino residential construction workers
Authors: Arcury Thomas A. , Mills Thomas , Marín Antonio J. , Summers Phillip , Quandt Sara A. , Rushing Julia , Lang Wei , Grzywacz Joseph G.
Published: April 2012

Background

Latino residential construction workers experience high rates of occupational fatality and injury. Work safety climate is an especially important consideration for improving the safety of these immigrant workers. This analysis describes work safety climate among Latino residential construction workers, delineates differences in work safety climate by personal and employment characteristics, and determines associations of work safety climate with specific work safety behaviors.

Methods

Data are from a cross‐sectional survey of 119 Latino residential framers, roofers, and general construction workers in western North Carolina; 90 of these participants also provided longitudinal daily diary data for up to 21 days using an Interactive Voice Response (IVR) system. Measures included the Perceived Safety Climate Scale, and daily reports of five individual and five collective safety practices.

Results

Work safety climate was mixed among workers, with roofers (19.9) having lower levels than framers (24.3) or general construction workers (24.3). Days reported for several individual (glove‐related risks, not doing something known to be unsafe) and collective safety practices (attended daily safety meeting, not needing to use damaged equipment, not seeing coworker create an unsafe situation) were positively associated with work safety climate.

Conclusions

Work safety climate predicts subsequent safety behaviors among Latino residential construction workers, with differences by trade being particularly important. Interventions are needed to improve safety training for employers as well as workers. Further research should expand the number of workers and trades involved in analyses of work safety climate. Am. J. Ind. Med. 55:736–745, 2012. © 2012 Wiley Periodicals, Inc.
Variations in peak expiratory flow measurements associated to air pollution and allergic sensitization in children in Sao Paulo, Brazil
Authors: Correia‐Deur Joya Emilie de M. , Claudio Luz , Imazawa Alice Takimoto , Eluf‐Neto Jose
Published: April 2012

Background

In the last 20 years, there has been an increase in the incidence of allergic respiratory diseases worldwide and exposure to air pollution has been discussed as one of the factors associated with this increase. The objective of this study was to investigate the effects of air pollution on peak expiratory flow (PEF) and FEV1 in children with and without allergic sensitization.

Methods

Ninety‐six children were followed from April to July, 2004 with spirometry measurements. They were tested for allergic sensitization (IgE, skin prick test, eosinophilia) and asked about allergic symptoms. Air pollution, temperature, and relative humidity data were available.

Results

Decrements in PEF were observed with previous 24‐hr average exposure to air pollution, as well as with 3–10‐day average exposure and were associated mainly with PM10, NO2, and O3 in all three categories of allergic sensitization. Even though allergic sensitized children tended to present larger decrements in the PEF measurements they were not statistically different from the non‐allergic sensitized. Decrements in FEV1 were observed mainly with previous 24‐hr average exposure and 3‐day moving average.

Conclusions

Decrements in PEF associated with air pollution were observed in children independent from their allergic sensitization status. Their daily exposure to air pollution can be responsible for a chronic inflammatory process that might impair their lung growth and later their lung function in adulthood. Am. J. Ind. Med. 55:1087–1098, 2012. © 2012 Wiley Periodicals, Inc.
A decade of malignant mesothelioma surveillance in Korea
Authors: Jung Soon‐Hee , Kim Hyoung‐Ryoul , Koh Sang‐Baek , Yong Suk‐Joong , Chung Myoung Ja , Lee Chang‐Hun , Han Joungho , Eom Min‐Seob , Oh Sung‐Soo
Published: April 2012

Background

The objectives of this study were to examine trends in mesothelioma incidence over a decade and to identify histories of asbestos exposure among cases in Korea.

Methods

In 2001, The Korea Occupational Safety and Health Agency organized a nationwide cardiopulmonary pathology group and established a malignant mesothelioma surveillance system covering all general hospitals in Korea. Mesothelioma cases were reported to this surveillance system with information about age, gender, location, occupational history, asbestos exposure environment, date of diagnosis, diagnostic method, histopathologic subtype, occurrence site, and other clinical information. Additionally, an epidemiological survey was conducted using a structured verbal questionnaire to allow further evaluation of asbestos exposures.

Results

A total of 399 cases of malignant mesothelioma were reported in the last decade, translating to approximately 40 annual cases, and an annual average incidence rate of 0.83 cases per million. Of the 152 patients interviewed by occupational physicians, 56 had occupational asbestos exposure histories (36.8%). Their occupations and industries included construction (19.7%), automobile repair (5.9%), asbestos textile, shipbuilding and repair, refinery work, boiler making, and asbestos cement work. Another 31 patients had environmental asbestos exposure histories.

Conclusions

Surveillance data indicate that malignant mesothelioma incidence in Korea is, thus far, lower than that of other developed countries, and that construction and environmental asbestos exposure were the main identifiable causes of malignant mesothelioma. Am. J. Ind. Med. 55:869–875, 2012. © 2012 Wiley Periodicals, Inc.
Women's knowledge, attitudes, and beliefs about Down syndrome: A qualitative research study
Authors: Levis Denise M. , Harris Shelly , Whitehead Nedra , Moultrie Rebecca , Duwe Kara , Rasmussen Sonja A.
Published: April 2012

Women who are or may become pregnant need up‐to‐date information about Down syndrome (DS). Asking women about their knowledge, opinions, resources, and information needs on the topic of DS is an important precursor to develop effective strategies for education. We conducted 24 focus groups (N = 111) in two US cities with women who were recently pregnant (who had a child ≤3 years old without DS) and women who planned to have a child in the next year. Groups were further segmented by age and race‐ethnicity. Questions explored women's knowledge, attitudes, and beliefs about DS; resources used to obtain information about health and DS; and information needs on the topic of DS. All participants reported having some knowledge of DS: facial features, chromosomal condition, and maternal age as a risk factor. Many participants had misconceptions, including the life expectancy for persons with DS, other maternal and paternal risk factors, and the idea that having a child with DS would disrupt their lives. Participants requested stories to help illustrate what life is like for families with DS. Many Hispanic and African American participants said they only saw or knew of Caucasian persons with DS and requested culturally diverse educational materials about DS. Participants said they would seek information on DS from the Internet and from their health care providers. Results suggest that women need tailored materials that contain clinical information about DS as well as information about living with a child with DS. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.
Candidate locus analysis for PHACE syndrome
Authors: Mitchell Sheri , Siegel Dawn H. , Shieh Joseph T.C. , Stevenson David A. , Grimmer J. Fredrik , Lewis Tracey , Metry Denise , Frieden Ilona , Blei Francine , Kayserili Hulya , Drolet Beth A. , Bayrak‐Toydemir Pinar
Published: April 2012

PHACE syndrome (OMIM #606519) is a neurocutaneous syndrome of unknown etiology and pathogenesis. We report on an individual with PHACE syndrome with a complete deletion of SLC35B4 on 7q33. In order to further analyze this region, SLC35B4 was sequenced for 33 individuals with PHACE syndrome and one parental set. Common polymorphisms with a possible haplotype but no disease causing mutation were identified. Sixteen of 33 samples of the PHACE syndrome patients were also analyzed for copy number variations using high‐resolution oligo‐comparative genomic hybridization (CGH) microarray. A second individual in this cohort had a 26.5 kb deletion approximately 80 kb upstream of SLC35B4 with partial deletion of the AKR1B1 on 7q33. The deletions observed on 7q33 are not likely the singular cause of PHACE syndrome; however, it is possible that this region provides a genetic susceptibility to phenotypic expression with other confounding genetic or environmental factors. © 2012 Wiley Periodicals, Inc.
Effect of non‐rubber substances on vulcanization kinetics of natural rubber
Authors: Ping‐Yue Wang , Yong‐Zhou Wang , Bei‐Long Zhang , Hong‐Hai Huang
Published: April 2012

Effect of non‐rubber components on vulcanization kinetics of natural rubber was studied with the use of a Rheometer MDR‐2000. The results show that the rate constants of induction period and curing period of natural rubber (NR) are greater than that of natural rubber extracted with acetone (NRE), and the activation energies of induction period and curing period of NR are lower than that of NRE. The activation energy of induction period of NR is reduced by16.9% and the activation energy of curing period of NR is reduced by 3.2% compared to the activation energies of NRE. The time tdis of NR is shorter than that of NRE at the same temperature. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Toughening of polylactide by melt blending with methyl methacrylate–butadiene–styrene copolymer
Authors: Zhang Huiliang , Liu Nanan , Ran Xianghai , Han Changyu , Han Lijing , Zhuang Yugang , Dong Lisong
Published: April 2012

Brittle polylactide (PLA) was toughened by introducing 5–25 wt % of methyl methacrylate–butadiene–styrene (MBS) copolymer. PLA/MBS blends were characterized by dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), dynamic rheometer, mechanical testing, scanning electron microscopy, and transmission electron microscope. From the result of DSC, MBS could act as an effective heterogeneous nucleation agent for PLA and significantly improved the degree of crystallinity of PLA. DMA results showed a single high temperature peak of Tg between that of pure PLA and that of the shell composition of the MBS, which suggested that PLA and the shell of MBS were compatible. With an increase of MBS content, the tensile strength of the blends decreased; however, the elongation at break and impact strength increased significantly which indicated the toughening effects of the MBS on PLA. It was found that the PLA matrix showed large plastic deformation (shear yielding) in the blend subjected the impact tests, which was an important energy‐dissipation process and led to a toughened polymer blend. MBS could act as impact modifier of PLA. Rheological investigation demonstrated that there was a significantly dependence of viscosity on composition. When the MBS content increased, the viscosity began to increase. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Hydrophilic modification of poly(vinylidene fluoride) membrane with poly(vinyl pyrrolidone) via a cross‐linking reaction
Authors: Bi Qiuyan , Li Qian , Tian Ye , Lin Yakai , Wang Xiaolin
Published: April 2012

A highly hydrophilic hollow fiber poly(vinylidene fluoride) (PVDF) membrane [PVDF‐cl‐poly(vinyl pyrrolidone) (PVP) membrane] was prepared by a cross‐linking reaction with the hydrophilic PVP, which was immobilized firmly on the outer surface and cross‐section of the PVDF hollow fiber membrane via a simple immersion process. The cross‐linking between PVDF and PVP was firstly verified via nuclear magnetic resonance measurement on PVP solution after cross‐linking. The hydrophilic stability of the modified PVDF membrane was evaluated by measuring the pure water flux after different times of immersion and drying. The anti‐fouling properties were estimated by cyclic filtration of protein solution. When the cross‐linking time was as long as 6 hr and the PVP content reached 5 wt %, the pure water flux (Jv) was constant as ∼ 600 L m−2 hr−1. The hydrophilicity of the PVDF‐cl‐PVP membrane was significantly enhanced and exhibited a good stability. The PVDF‐cl‐PVP membrane showed an excellent anti‐protein‐fouling performance during the cyclic filtration of bovine serum albumin solution. Therefore, a highly hydrophilic and anti‐protein‐fouling PVDF hollow fiber membrane with a long‐term stability can be prepared by a simple and economical cross‐linking process with PVP. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of isotactic polypropylene/fibrous cellulose composite oxo‐biodegradation induced by poly(ethylene oxide)/TiO2 initiator and accelerator system
Authors: Miyazaki Kensuke , Shibata Kazuto , Nakatani Hisayuki
Published: April 2012

In this work, a novel isotactic polypropylene (PP)/fibrous cellulose (FC) composite containing a poly(ethylene oxide) (PEO)/TiO2 was prepared, and its oxo‐biodegradation behavior was studied. FC loading of 5 and 1% resulted in an opaque film and relatively good transparence, respectively. Fourier transform infrared (FTIR) spectra of the nonphotodegraded composite samples revealed little PP auto‐oxidation under the melt‐mixing condition. Ultraviolet irradiation enhanced the auto‐oxidation of the composite. FTIR analyses of the composite indicated that TiO2 and PEO functioned as the initiator and accelerator of PP auto‐oxidation, respectively. In addition, even with 1% PEO, the accelerator effect was enhanced by the spreading of the degraded PEO component from other areas when the film thickness was increased. All PP/PEO/TiO2/FC composites with a PEO content varying from 0.3 to 5% showed a Young's modulus value of ∼ 180% higher than that of pristine PP. Biodegradability of the photodegraded composite was confirmed by a soil burial test. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Thermosetting allyl resins derived from soybean fatty acids
Authors: Luo Qiang , Lui Min , Xu Yijin , Ionescu Mihail , Petrovic Zoran S.
Published: April 2012

A novel class of thermosetting resins based on allylated and transesterified epoxidized soybean oil (AE‐ESBO) curable by radical mechanism was developed. The AE‐ESBO was prepared from ESBO by oxirane ring‐opening and then transesterification with allyl alcohol. A family of rubbery to glassy resins was prepared by radical copolymerization of AE‐ESBO with different concentrations of maleic anhydride (MA). Glass transition temperatures (Tg) of these resins ranged from below room temperature to about 130°C based on the amount of MA. In spite of the presence of anhydride groups, water absorption was low <2% even when maleic anhydride was 30% of total weight. Low sol content after extraction and low swelling in toluene indicated high crosslinking density. Tensile moduli of these resins were up to 1.4 GPa and tensile strengths up to 37 MPa. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation and characterization of polysaccaride interpolymer complexes: I‐PVA/ι‐carrageenan
Authors: Kantoğlu Ömer , Çaykara Tuncer , Güven Olgun
Published: April 2012

Thermal and spectroscopic charaterization of PVA, iota carrageenan (IC), and their interpolymer complexes were studied in terms of stability, complex formation, and species determination by XRF, FTIR, Raman, DSC, and TGA. Thermogravimetry analysis showed that initial thermal degradation temperature of PVA/IC decreased from 276 to 256°C with an increase of IC content. The complexation of IC to PVA significantly increased, the thermal stability of IC, where as the thermal stability of PVA increased rather insignificantly. Fourier Transform Infrared (FTIR) and Raman spectroscopic results showed that PVA interacted with IC through OH groups of PVA and IC as shown by the frequency and scattering shift at OH band of FTIR and Raman spectra of each complex. The involvements of ester sulfate and ether groups of IC in interaction were not significant. In the results of the thermal and spectroscopic analysis, 17% content of PVA/IC is the most miscible and intercomplexable weight fraction of PVA/IC. The natural source of IC, which was unknown was characterized by XRF and found to be as potassium salt and Euchema specie of marine red algee of the class Rhodophceae. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Compression molding of biodegradable drug‐eluting implants for sustained release of metronidazole and doxycycline
Authors: Kau Yi‐Chuan , Chen Dave Wei‐Chih , Hsieh Yu‐Te , Lee Fu‐Ying , Liu Shih‐Jung
Published: April 2012

The purpose of this report was to develop solvent‐free biodegradable drug‐eluting implants that provide sustained release of metronidazole and doxycycline. The drug‐eluting implants were prepared using the compression molding technique. To fabricate the implants, polylactide‐polyglycolide copolymers were premixed with metronidazole or doxycycline. The mixture was then compression molded and sintered to form implants of various sizes and geometries. An elution method and an HPLC assay were used to characterize the in vitro release rates of the antibiotics over a 28‐day period. A bacterial inhibition test was also carried out to determine the bioactivity of released antibiotics. The concentrations of both metronidazole and doxycycline were much greater than the minimum inhibitory concentration of Escherichia coli for up to 3 and 4 weeks, respectively, and the bioactivities of the antibiotics remained high after the fabrication process. Furthermore, the initial burst could be minimized and the release rate could be reduced by increasing the size of the implants and by adopting low drug to polymer ratios. By using this compression molding technique and appropriate processing parameters, we will be able to fabricate biodegradable implants of various types of antibacterial drugs for long‐term local deliveries. Eventually, biodegradable drug‐eluting implants may be used to treat various periodontal diseases. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Lignocellulosic byproducts as filler in polypropylene: Comprehensive study on the effects of compatibilization and loading
Authors: Fuqua Michael A. , Chevali Venkata S. , Ulven Chad A.
Published: April 2012

Lignocellulosic byproducts derived from biofuel processes were analyzed as functional fillers in polypropylene‐based biocomposites. Corn cob, a byproduct yielded from corn harvesting for ethanol production, and sunflower hull, a byproduct of seed stripping for biodiesel production, were both examined as ground filler agents. Composite blends with these lignocellulosic fillers at four filler loadings and four variants of surface compatibilizer loading were melt‐compounded using a twin screw extruder and injection molded into test specimens. Tensile testing, notched Izod impact testing, and thermal‐mechanical analysis were performed on the composites. The role of filler type, loading, and surface compatibilization were established and reported. Additionally, elastic modulus and tensile strength were successfully modeled using established particulate composite models. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effects of waste ground fluororubber vulcanizate powders on the properties of silicone rubber/fluororubber blends
Authors: Kim Dae Hyun , Hwang Sung Hyuk , Park Tae Sung , Kim Bong Shik
Published: April 2012

We prepared fluororubber (FKM) vulcanizate powder (FVP) via cryogenic grinding of the FKM commonly used in automobiles and assessed the particle size distribution of the resulting powder. We also prepared silicone rubber (SR)/FKM blends at a ratio of 25/75. Varying amounts of FKM were replaced with equal amounts of FVP within the range of 5–40 wt%, and the physical properties of the resulting SR/FKM/FVP blends were investigated and compared. The TGA curves of the SR/FKM/FVP blends obtained during the thermal property investigations indicated that pyrolysis of SR occurred within two temperature ranges, and that the SR/FKM/FVP blends with 5 wt% FVP demonstrated the highest thermal stability. The storage modulus (E') and loss modulus (E″) of the SR/ FKM/FVP blends increased as the FVP content increased. In the SR/FKM/FVP blends with 5 and 10 wt% FVP, very typical elastic‐deformation behavior was observed. On the contrary, in 40 wt% FVP, the rubber properties disappeared. The mean particle size of FVP was 41.75 μm, and particle size distribution measurements of the SR/FKM/FVP blends suggest particle coexistence such that FVP was condensed and separated. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
In situ formation of biodegradable dextran‐based hydrogel via Michael addition
Authors: Peng Geng , Wang Jing , Yang Fan , Zhang Shuo , Hou Juan , Xing Wanli , Lu Xun , Liu Changsheng
Published: April 2012

Vinyl‐sulfone‐functionalized dextran (Dex‐VS) was readily prepared by a single‐batch synthetic procedure at room temperature. The thiol molecule, 1,4‐dithioerythritol (DTE, commercially available) with two terminal thiol groups was used as crosslinking agent. Hydrogels were rapidly prepared in situ by Michael addition under mild physiological conditions. Properties including gelation duration, mechanical modulus, and degradation behavior could be expediently controlled. Moreover, the hydrogels had comparatively low cytotoxicity, and the in vivo tests demonstrated an effective delivery of growth factor. This study might provide a powerful material to be used in tissue regeneration. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of radiation crosslinked foams from low‐density polyethylene/ethylene‐vinyl acetate (LDPE/EVA) copolymer blend with a supercritical carbon dioxide approach
Authors: Wang Bo , Wang Mouhua , Xing Zhe , Zeng Hongyan , Wu Guozhong
Published: April 2012

Low‐density polyethylene/ethylene‐vinyl acetate copolymer (LDPE/EVA) blend foams were prepared by a combination of radiation and supercritical carbon dioxide (ScCO2) approach. The radiation effects on LDPE/EVA foams in different ratios were investigated in detail. For the LDPE/EVA blend in a w/w ratio of 70/30, the cell size decreased and the cell density increased with an increase of absorbed dose. The optimal dose and EVA content for the foaming of LDPE/EVA blend in ScCO2 was found to be 50 kGy and 30%, respectively. It was also found that the radiation crosslinked LDPE/EVA blends had a wider foaming temperature range than uncrosslinked samples. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Nitroanilines enhancing the holographic data storage characteristics of the 9,10‐phenanthrenequinone‐doped poly(methyl methacrylate) photopolymer
Authors: Ko Cheng‐Jung , Hsiao Yi‐Nan , Lin Shiuan‐Huei , Chen Po‐Lin , Whang Wha‐Tzong , Hsu Ken Y. , Hsiao Yu‐Sheng , Chen Chun‐Chao
Published: April 2012

This article describes an approach toward improving the characteristics of a photopolymer for holographic data storage application. The maximum diffraction efficiency (ηmax) and dynamic range (M#) of 9,10‐phenanthrenequinone (PQ)‐doped poly(methyl methacrylate; PMMA) both improved significantly after co‐doping with one of three nitroanilines—N,N‐dimethyl‐4‐nitroaniline (DMNA), N‐methyl‐4‐nitroaniline (MNA), and 4‐nitroaniline (pNA). In particular, the value of ηmax increased from 38% for the PMMA/PQ system to 72% for the PMMA/PQ/DMNA system (a 1.89‐fold improvement) and the value of M# increased accordingly from 2.7 to 7.3 (a 2.70‐fold improvement). Thus, the holographic data storage characteristics of PMMA/PQ photopolymers can be improved through co‐doping with nitroaniline compounds. We also investigated the mechanism of the nitroaniline‐induced improvement in optical storage performance using proton nuclear magnetic resonance and X‐ray photoelectron spectroscopy. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Composite materials of graphene nanoplatelets and polypropylene, prepared by in situ polymerization
Authors: Polschikov Sergey V. , Nedorezova Polina M. , Klyamkina Alla N. , Kovalchuk Anton A. , Aladyshev Alexander M. , Shchegolikhin Alexander N. , Shevchenko Vitaliy G. , Muradyan Vyacheslav E.
Published: April 2012

Nanocomposites of polypropylene and graphene nanoplatelets were synthesized by in situ polymerization in liquid monomer in the presence of highly effective isospecific homogeneous metallocene catalyst. Microstructure, mechanical, dielectric, and thermal properties of composites are presented. X‐ray phase analysis data indicate that graphene nanoplatelets are present in composites as thin flaky particles aggregates, with aspect ratio affected by sonication of reaction mixture. Crystallization temperature of polypropylene increases in composites. Nanocomposites are characterized by high rigidity, thermal stability, and crystallization temperature, low conductivity, and high dielectric losses in the microwave range. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Synthesis of cationic polyacrylamide by aqueous two‐phase polymerization in poly(ethylene glycol) chloride solution
Authors: Liu Zaiman , Wei Yaling , Li Baiyu , He Naipu
Published: April 2012

Aqueous two‐phase copolymerization of acrylamide(AM) and acryloyloxyethyl trimethyl ammonium chloride (DAC) was performed in poly(ethylene glycol) (PEG) solution and in PEG chloride(Cl‐PEG) solution, respectively. Series of cationic polyacrylamide(CPAM) aqueous dispersion were prepared using potassium persulfate (KPS) as initiator. The effect of total amount of monomers, the dosage of initiator, the content of dispersant, the mass ratio of AM to DAC, and the temperature on the conversion, molecular weight, cationic degree, and stability of aqueous dispersion were studied in detail. It is found that the increase of initiator and reaction temperature resulted in the increase of the final conversion, whereas the increase of DAC and PEG concentration resulted in the decrease of the final conversion. The optimum reaction conditions of synthesis were as follows: (1) PEG‐H2O system: PEG 7.5 g, AM 8 g, DAC 2 g, KPS 0.05 g, H2O 100 mL, 70°C. In this process conditions, the molecular weight of CPAM was 3.21 × 106, the cationic degree of CPAM was 24.4%, the storage stability of the aqueous dispersion was over 3 months. (2) Cl‐PEG‐H2O system: Cl‐PEG 7.5 g, AM 8 g, DAC 2 g, KPS 0.05 g, H2O 100 mL, 65°C. In this process conditions, the molecular weight was 3.68 × 106, the cationic degree was 23.3%, and the storage stability of the aqueous dispersion was over 6 months. In general, the stability of CPAM aqueous dispersion in Cl‐PEG system is much better than in PEG system. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013