bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a high spectral resolution surface albedo product for the ARM Southern Great Plains central facility
Authors: McFarlane S. A. , Gaustad K. L. , Mlawer E. J. , Long C. N. , Delamere J.
Published: September 2011

Abstract. We present a method for identifying dominant surface type and estimating high spectral resolution surface albedo at the Atmospheric Radiation Measurement (ARM) facility at the Southern Great Plains (SGP) site in Oklahoma for use in radiative transfer calculations. Given a set of 6-channel narrowband visible and near-infrared irradiance measurements from upward and downward looking multi-filter radiometers (MFRs), four different surface types (snow-covered, green vegetation, partial vegetation, non-vegetated) can be identified. A normalized difference vegetation index (NDVI) is used to distinguish between vegetated and non-vegetated surfaces, and a scaled NDVI index is used to estimate the percentage of green vegetation in partially vegetated surfaces. Based on libraries of spectral albedo measurements, a piecewise continuous function is developed to estimate the high spectral resolution surface albedo for each surface type given the MFR albedo values as input. For partially vegetated surfaces, the albedo is estimated as a linear combination of the green vegetation and non-vegetated surface albedo values. The estimated albedo values are evaluated through comparison to high spectral resolution albedo measurements taken during several Intensive Observational Periods (IOPs) and through comparison of the integrated spectral albedo values to observed broadband albedo measurements. The estimated spectral albedo values agree well with observations for the visible wavelengths constrained by the MFR measurements, but have larger biases and variability at longer wavelengths. Additional MFR channels at 1100 nm and/or 1600 nm would help constrain the high resolution spectral albedo in the near infrared region.
A new approach to sensitivity climatologies: the DTS-MEDEX-2009 campaign
Authors: Jansa A. , Arbogast P. , Doerenbecher A. , Garcies L. , Genoves A. , Homar V. , Klink S. , Richardson D. , Sahin C.
Published: September 2011

Abstract. Adaptive observation is an approach to improving the quality of numerical weather forecasts through the optimization of observing networks. It is sometimes referred to as Data Targeting (DT). This approach has been applied to high impact weather during specific field campaigns in the past decade. Adaptive observations may involve various types of observations, including either specific research observing platforms or routine observing platforms employed in an adaptive way. The North-Atlantic TReC 2003 and the EURORISK-PREVIEW 2008 exercises focused on the North-Atlantic and Western Europe areas using mainly routine observing systems. These campaigns also included Mediterranean cases. The most recent campaign, DTS-MEDEX-2009, is the first campaign in which the DT method has been used to address exclusively Mediterranean high impact weather events. In this campaign, which is an important stage in the MEDEX development, only operational radiosonde stations and commercial aircraft data (AMDAR) have provided additional observations. Although specific diagnostic studies are needed to assess the impact of the extra-observations on forecast skill and demonstrate the effectiveness of DTS-MEDEX-2009, some preliminary findings can be deduced from a survey of this targeting exercise. After a description of the data targeting system and some illustrations of particular cases, this paper attempts some comparisons of additional observation needs (through effectively deployed radio-soundings) with sensitivity climatologies in the Mediterranean. The first step towards a sensitivity climatology for Mediterranean cases of high impact weather is indirectly given by the frequency of extra-soundings launched from the network of radiosonde stations involved in the DTS-MEDEX-2009 campaign.
Rapidly Progressive, Fatal, Inhalation Anthrax-like Infection in a Human: Case Report, Pathogen Genome Sequencing, Pathology, and Coordinated Response
Authors: Wright Angela M. , Beres Stephen B. , Consamus Erin N. , Long S. Wesley , Flores Anthony R. , Barrios Roberto , Richter G Stefan , Oh So-Young , Garufi Gabriella , Maier Hannah , Drews Ashley L. , Stockbauer Kathryn E. , Cernoch Patricia , Schneewind Olaf , Olsen Randall J. , Musser James M.
Published: September 2011

Context.—Ten years ago a bioterrorism event involving Bacillus anthracis spores captured the nation's interest, stimulated extensive new research on this pathogen, and heightened concern about illegitimate release of infectious agents. Sporadic reports have described rare, fulminant, and sometimes fatal cases of pneumonia in humans and nonhuman primates caused by strains of Bacillus cereus, a species closely related to Bacillus anthracis.

Objectives.—To describe and investigate a case of rapidly progressive, fatal, anthrax-like pneumonia and the overwhelming infection caused by a Bacillus species of uncertain provenance in a patient residing in rural Texas.

Design.—We characterized the genome of the causative strain within days of its recovery from antemortem cultures using next-generation sequencing and performed immunohistochemistry on tissues obtained at autopsy with antibodies directed against virulence proteins of B anthracis and B cereus.

Results.—We discovered that the infection was caused by a previously unknown strain of B cereus that was closely related to, but genetically distinct from, B anthracis. The strain contains a plasmid similar to pXO1, a genetic element encoding anthrax toxin and other known virulence factors. Immunohistochemistry demonstrated that several homologs of B anthracis virulence proteins were made in infected tissues, likely contributing to the patient's death.

Conclusions.—Rapid genome sequence analysis permitted us to genetically define this strain, rule out the likelihood of bioterrorism, and contribute effectively to the institutional response to this event. Our experience strongly reinforced the critical value of deploying a well-integrated, anatomic, clinical, and genomic strategy to respond rapidly to a potential emerging, infectious threat to public health.
Physical activity and body composition in patients with ankylosing spondylitis
Authors: Plasqui G. , Boonen A. , Geusens P. , Kroot E. J. , Starmans M. , van der Linden S.
Published: September 2011

Objective

Patients with ankylosing spondylitis (AS) are at risk for accelerated muscle loss and reduced physical activity. Accurate data are needed on body composition and physical activity in this patient group. The purpose of this study was to investigate body composition and objectively assessed physical activity in patients with AS.

Methods

Twenty‐five AS patients (15 men, mean ± SD age 48 ± 11 years) were compared with 25 healthy adults matched for age, sex, and body mass index. Body composition was measured using a 3‐compartment model based on air‐displacement plethysmography to assess body volume and deuterium dilution to assess total body water. The fat‐free mass index (FFMI; fat‐free mass divided by height squared) and the percent fat mass (%FM) were calculated. Daily physical activity was assessed for 7 days using a triaxial accelerometer and physical fitness with an incremental test until exertion on a bicycle ergometer. Blood samples were taken to determine C‐reactive protein (CRP) level and tumor necrosis factor α.

Results

Accelerometer output (kilocounts/day) showed the same physical activity level for patients and controls (mean ± SD 319 ± 105 versus 326 ± 66). There was no difference in the FFMI or %FM between the patients and controls. Physical activity was positively related to the FFMI (partial R = 0.38, P = 0.01) and inversely related to CRP level (R = −0.39, P < 0.01), independent of group. CRP level was inversely related to the FFMI, but the effect was less strong than with physical activity (partial R = −0.31, P = 0.03).

Conclusion

Daily physical activity may help preserve fat‐free mass in patients with AS.
Matched‐cohort study of body composition, physical function, and quality of life in men with idiopathic vertebral fracture
Authors: Macdonald Jamie H. , Evans Sally F. , Davies Helen L. , Wilson Sally , Davie Michael W. J. , Sharp Christopher A.
Published: September 2011

Objective

To determine the effect of 6 years of routine management on body composition, physical functioning, and quality of life, and their interrelationships, in men with idiopathic vertebral fracture.

Methods

Twenty men with idiopathic vertebral fracture (patients: mean ± SD age 58 ± 6 years) were age and height matched to 28 healthy controls with no known disease. The primary outcome was skeletal muscle mass (appendicular lean mass by dual x‐ray absorptiometry) assessed at 2 visits (0 and 6 years). Physical functioning and quality of life domains were assessed by the Senior Fitness Test and Short Form 36 (SF‐36) questionnaire at visit 2 only. Data were analyzed by repeated‐measures analysis of variance, independent t‐tests, and correlation.

Results

At visit 1, appendicular lean mass was 9% lower in patients than controls. Although patients better maintained appendicular lean mass between visits (interaction P = 0.016), at visit 2 appendicular lean mass remained 5% lower in patients than controls. Furthermore, patients' appendicular lean mass change was correlated with femoral neck bone density change (r = 0.507, P = 0.023). Physical function tests were 13–27% lower in patients compared with controls (P = 0.056 to 0.003), as were SF‐36 quality of life physical domains (13–26% lower; P = 0.028 to <0.001).

Conclusion

Despite an association between changes in muscle mass and bone density, routine management of men with idiopathic vertebral fracture does not address muscle loss. Combined with the observation of reduced physical functioning and quality of life, this study identifies novel targets for intervention in men with idiopathic vertebral fracture.
Incident vertebral fractures among children with rheumatic disorders 12 months after glucocorticoid initiation: A national observational study
Authors: Rodd Celia , Lang Bianca , Ramsay Timothy , Alos Nathalie , Huber Adam M. , Cabral David A. , Scuccimarri Rosie , Miettunen Paivi M. , Roth Johannes , Atkinson Stephanie A. , Couch Robert , Cummings Elizabeth A. , Dent Peter B. , Ellsworth Janet , Hay John , Houghton Kristin , Jurencak Roman , Larché Maggie , LeBlanc Claire , Oen Kiem , Saint‐Cyr Claire , Stein Robert , Stephure David , Taback Shayne , Lentle Brian , Matzinger Maryann , Shenouda Nazih , Moher David , Rauch Frank , Siminoski Kerry , Ward Leanne M. ,   Canadian Steroid‐Associated Osteoporosis in the Pediatric Population (STOPP) Consortium
Published: September 2011

Objective

To determine the frequency of incident vertebral fractures (IVF) 12 months after glucocorticoid (GC) initiation in children with rheumatic diseases and to identify children at higher risk.

Methods

Children with rheumatic diseases initiating GC were enrolled in a prospective observational study. Annual spine radiographs were evaluated using the Genant semiquantitative method. Spine areal bone mineral density (aBMD) was measured every 6 months. Clinical features, including cumulative GC dose, back pain, disease and physical activity, calcium and vitamin D intake, and spine aBMD Z scores, were analyzed for association with IVF.

Results

Seven (6%) of 118 children (95% confidence interval 2.9–11.7%) had IVF. Their diagnoses were: juvenile dermatomyositis (n = 2), systemic lupus erythematosus (n = 3), systemic vasculitis (n = 1), and mixed connective tissue disease (n = 1). One child was omitted from the analyses after 4 months because of osteoporosis treatment for symptomatic IVF. Children with IVF received on average 50% more GC than those without (P = 0.030), had a greater increase in body mass index (BMI) at 6 months (P = 0.010), and had greater decrements in spine aBMD Z scores in the first 6 months (P = 0.048). Four (67%) of 6 children with IVF and data to 12 months had spine aBMD Z scores less than −2.0 at 12 months compared to 16% of children without IVF (P = 0.011).

Conclusion

The incidence of VF 12 months following GC initiation was 6%; most children were asymptomatic. Children with IVF received more GC, had greater increases in BMI, and had greater declines in spine aBMD Z scores in the first 6 months.
A Mussel Adhesive Protein Fused with the BC Domain of Protein A is a Functional Linker Material that Efficiently Immobilizes Antibodies onto Diverse Surfaces
Authors: Kim Chang Sup , Choi Yoo Seong , Ko Wooree , Seo Jeong Hyun , Lee Jieun , Cha Hyung Joon
Published: September 2011

The efficient immobilization of antibodies onto solid surfaces is vital for the sensitivity and specificity of various immunoassays and immunosensors. A novel linker protein, BC‐MAP, is designed and produced in Escherichia coli by genetically fusing mussel adhesive protein (MAP) with two domains (B and C) of protein A (antibody‐binding protein) for efficient antibody immobilization on diverse surfaces. Through direct surface‐coating analyses, it is found that BC‐MAP successfully coats diverse surfaces including glass, polymers, and metals, but the BC domain alone does not. Importantly, antibodies are efficiently immobilized on BC‐MAP‐coated surfaces, and the immobilized antibodies interact selectively with their corresponding antigen. Quartz‐crystal‐microbalance analyses show that BC‐MAP has excellent antibody‐binding ability compared to that of BC protein on gold surfaces. These results demonstrate that the MAP domain, with uniquely strong underwater adhesive properties, plays a role in the direct and efficient coating of BC‐MAP molecules onto diverse surfaces that lack additional surface treatment, and the BC domain of BC‐MAP contributes to the selective and oriented immobilization of antibodies on BC‐MAP‐coated surfaces. Thus, the BC‐MAP fusion protein could be a valuable novel linker material for the facile and efficient immobilization of antibodies onto diverse solid supports.
Highly Enantioselective Hydrogenation of β‐Acyloxy and β‐Acylamino α,β‐Unsaturated Phosphonates Catalyzed by Rhodium Phosphane‐Phosphite Complexes
Authors: Chávez M. Ángeles , Vargas Sergio , Suárez Andrés , Álvarez Eleuterio , Pizzano Antonio
Published: September 2011

The enantioselective hydrogenation of β‐(acyloxy)‐ and β‐(acylamino)vinylphosphonates with rhodium catalysts based on chiral phosphane‐phosphite ligands has been studied. In the case of the β‐(acyloxy)vinylphosphonates, the reaction also produces an achiral phosphonate resulting from the elimination of the benzoate group. High ligand modularity has led to a highly chemo‐ and enantioselective catalyst for both types of substrates, which afford a good range of β‐acyloxy‐ and β‐acylaminophosphonates with enantioselectivities between 90 and 99% ee. Most interestingly, the configuration of the hydrogenation products indicates the same stereochemical sense for the reduction of both types of substrates, which is opposite to that observed before for α‐(acyloxy)vinylphosphonates. This observation has been rationalized by assuming the formation of a β‐alkyl intermediate during the catalytic cycle, which also explains the formation of the elimination product in the hydrogenation of the β‐(acyloxy)‐vinylphosphonates.
Stereoselective Reduction of 2‐Hydroxy Ketones towards syn‐ and anti‐1,2‐Diols
Authors: Husain Syed Masood , Stillger Thomas , Dünkelmann Pascal , Lödige Melanie , Walter Lydia , Breitling Elke , Pohl Martina , Bürchner Mara , Krossing Ingo , Müller Michael , Romano Diego , Molinari Francesco
Published: September 2011

Stereoselective reduction of 2‐hydroxy ketones should in principle give access to syn‐ and anti‐1,2‐diols. anti‐1,2‐Diols are accessible in a highly selective way using zinc borohydride [Zn(BH4)2] under chelation control (dr>20:1). Diastereoselective reduction of unprotected or even protected 2‐hydroxy ketones towards syn‐1,2‐diols could be achieved only with moderate selectivity of dr≤5:1. Even when using sterically demanding protecting groups and/or polymer‐supported borohydride reagents high selectivity could not be achieved. A new ionic liquid‐dependent borohydride reduction method, although highly attractive with respect to reaction engineering, resulted in only moderate to good selectivity. An efficient two‐step biocatalytic method for the synthesis of syn‐1,2‐diols is described. The method relies on the whole‐cell Pichia glucozyma‐catalyzed stereoselective reduction of the unprotected (R)‐2‐hydroxy ketones (dr>10:1). The latter are accessible through thiamine diphosphate‐dependent enzyme‐catalyzed synthesis starting from simple aldehydes. Thus, biocatalytic transformations enable a process which is hardly accessible through present non‐enzymatic methods.
Enzymatic Asymmetric Synthesis of Enantiomerically Pure Aliphatic, Aromatic and Arylaliphatic Amines with (R)‐Selective Amine Transaminases
Authors: Schätzle Sebastian , Steffen‐Munsberg Fabian , Thontowi Ahmad , Höhne Matthias , Robins Karen , Bornscheuer Uwe T.
Published: September 2011

Seven (R)‐selective amine transaminases (R‐ATAs) recently discovered by an in silico‐based approach in sequence databases were produced recombinantly in Escherichia coli and subjected to partial purification by ammonium sulfate precipitation. A range of additives and various buffers were investigated to identify best conditions to ensure good storage stability and stable activity during biocatalysis. All enzymes show pH optima between pH 7.5–9. These R‐ATAs were then applied in the asymmetric synthesis of twelve aliphatic, aromatic and arylaliphatic (R)‐amines starting from the corresponding prochiral ketones using a lactate dehydrogenase/glucose dehydrogenase system to shift the equilibrium. For all ketones, at least one enzyme was found that allows complete conversion to the corresponding chiral amine having excellent optical purities >99% ee. Variations in substrate profiles are also discussed based on the phylogenetic relationships between the seven R‐ATAs. Thus, we have identified a versatile toolbox of (R)‐amine transaminases showing remarkable properties for application in biocatalysis.
Exposure to tobacco smoke and prevalence of symptoms decreased among Finnish Restaurant workers after the smoke‐free law
Authors: Reijula Jere P. , Johnsson Tom S.‐E. , Kaleva P. Simo , Reijula Kari E.
Published: September 2011

Introduction

The impact of tobacco legislation and exposure to environmental tobacco smoke (ETS) in bars and restaurants were assessed in a national survey.

Methods

Questionnaire surveys among restaurant workers were conducted in 2007 before the smoking ban, and in 2009.

Results

The exposure to ETS decreased significantly after the launch of the 2007 smoke‐free law. During 2007–2009, the prevalence of those restaurant workers with no exposure increased from 54% to 82% (P‐value < 0.0001), and among bartenders from 10% to 70% (P < 0.0001). Employees exposed daily for more than 4 hr decreased from 24% to 4% (P < 0.0001) and from 67% to 9% among bartenders (P < 0.0001). The prevalence of respiratory symptoms decreased from 18% to 4% (P < 0.0001) and of eye symptoms from 23% to 6% (P < 0.0001).

Conclusion

The reform of tobacco legislation in 2007, which prohibited smoking in restaurants and bars, significantly decreased the exposure to ETS and the prevalence of symptoms among restaurant workers. Am. J. Ind. Med. 55:37–43, 2012. © 2011 Wiley Periodicals, Inc.
No evidence of Neandertal admixture in the mitochondrial genomes of early European modern humans and contemporary Europeans
Authors: Ghirotto Silvia , Tassi Francesca , Benazzo Andrea , Barbujani Guido
Published: September 2011

Neandertals, the archaic human form documented in Eurasia until 29,000 years ago, share no mitochondrial haplotype with modern Europeans. Whether this means that the two groups were reproductively isolated is controversial, and indeed nuclear data have been interpreted as suggesting that they admixed. We explored the range of demographic parameters that may have generated the observed mitochondrial diversity, simulating 3.0 million genealogies under six models differing as for the relationships among contemporary Europeans, Neandertals, and Upper Palaeolithic European early modern humans (EEMH), who coexisted with Neandertals for millennia. We compared by Approximate Bayesian Computations the simulation results with mitochondrial diversity in 7 Neandertals, 3 EEMH, and 150 opportunely chosen modern Europeans. A model of genealogical continuity between EEMH and contemporary Europeans, with no Neandertal contribution, received overwhelming support from the analyses. The maximum degree of Neandertal admixture, under the model of gene flow supported by nuclear data, was estimated at 1.5%, but this model proved 20–32 times less likely than a model without any gene flow. Nuclear and mitochondrial evidence might be reconciled if smaller population sizes led to faster lineage sorting for mitochondrial DNA, and Neandertals shared a longer period of common ancestry with the non‐African's than with the African's ancestors. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Comparative insights into the regulation of inflammation: Levels and predictors of interleukin 6 and interleukin 10 in young adults in the Philippines
Authors: McDade Thomas W. , Tallman Paula S. , Adair Linda S. , Borja Judith , Kuzawa Christopher W.
Published: September 2011

Inflammation is a central part of innate immunity, but its role in anti‐pathogen defenses has been overshadowed by recent interest in the contribution of inflammation to a wide range of chronic degenerative diseases. Current research on chronic inflammation is conducted primarily in affluent populations with low levels of infectious disease; comparative research in different ecological settings is needed to advance understandings of the causes and consequences of variation in the regulation of inflammation. This article investigates the levels and predictors of interleukin‐6 (IL‐6) and interleukin‐10 (IL‐10)—two cytokines important to the regulation of inflammation—in a large, population‐based study in the Philippines. Concentrations of IL‐6 and IL‐10 were determined in N = 1,569 healthy young adults (20–22 years) in Metro Cebu, Philippines. IL‐6 and IL‐10 concentrations were positively correlated, and body mass index and symptoms of infectious disease were both associated with higher concentrations of IL‐6 and IL‐10. Median concentrations of IL‐6 (1.0 pg/mL) and IL‐10 (7.56 pg/mL) were substantially lower and higher, respectively, than levels reported for other populations based on a systematic review of prior research. This study contributes to a growing body of research in human ecological immunology, and suggests that there may be substantial population differences in the regulation of inflammation that has implications for the association between inflammation and disease. Am J Phys Anthropol, 2011. © 2011 Wiley‐Liss, Inc.
Deep catalytic oxidation of benzene, toluene, ethyl acetate over Pd/SBA‐15 catalyst: reaction behaviors and kinetics
Authors: He Chi , Yue Lin , Zhang Xinyan , Li Peng , Dou Baojuan , Ma Chunyan , Hao Zhengping
Published: September 2011

This work aimed at investigating the reaction behaviors and kinetics of catalytic oxidation of benzene, toluene, and ethyl acetate over Pd/SBA‐15 catalyst. Results for single components show that toluene (T50 = 185–215 °C) is more easily oxidized than ethyl acetate (T50 = 220–255 °C) and benzene (T50 = 215–290 °C). The conversion of toluene and benzene decreases continuously as their inlet concentrations are increased. The conversion of ethyl acetate increases slightly when its feed concentration increases in a small range, while this trend is not kept when the concentration is further raised. Results for multicomponents reveal that the presence of benzene or toluene inhibits the conversion of ethyl acetate, and the aromatic hydrocarbons inhibit each other. Ethyl acetate has an inhibitory effect on benzene, while it is interested to note that the promotion behaviors are observed for toluene. Kinetic results of all studied volatile organic compounds obtained in the absence of diffusion limitations are fit to the Mars‐van Krevelen expressions. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Influence of pyrolysis condition and coal type on char gasification reactivity
Authors: Wang Xianhua , Chen Hanping , Yang Haiping , Ju Fudong , Zhang Shihong
Published: September 2011

The CO2 gasification property of char particles was investigated with pressurized and ambient thermal analyzer with four typical Chinese industrial coals as samples. The influence of pyrolysis pressure and final temperature was analyzed and a new index (specific maximum gasification rate) of char CO2 gasification reactivity was approached. The process of char gasification can be divided into two steps: the thermal cracking and CO2 shifting of volatile hydrocarbon residues and the CO2 shifting of carbon matrix. Higher pressure did not show positive effect on char gasification enhancing as pyrolysis pressure lower than 1.5 MPa, whereas it was accelerated with pressure increasing further as more volatile hydrocarbon left in char particles. Temperature showed variant influence on char gasification with different pyrolysis pressures. There exist some interaction between pyrolysis temperature and pressure. Furthermore, coal type played vital role on char gasification behavior and the specific maximum gasification rate showed great consistency with char gasification behavior. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd.
Cyclohexene oxide mid‐chain functional macromonomer of poly(ε‐caprolactone): Synthesis, characterization, and photoinitiated cationic homo‐ and copolymerization
Authors: Degirmenci Mustafa , Acikses Aslisah , Genli Nasrettin
Published: September 2011

In this study, a novel well‐defined epoxy mid‐chain functional macromonomer of poly(ε‐caprolactone) (PCL) has been synthesized by ring‐opening polymerization (ROP) of ε‐caprolactone (ε‐CL) and epoxidation on workup with 3‐chloroperoxybenzoic acid. The ROP of ε‐CL monomer in bulk at 110°C, by means of a dihydroxy functional initiator namely, 3‐cyclohexene‐1,1‐dimethanol in conjunction with stannous‐2‐ethylhexanoate, (Sn(Oct)2), yielded a well‐defined PCL with a cyclohexene mid‐chain group. The epoxidation of the cyclohexene (CH) mid‐chain group of PCL was performed using 3‐chloroperoxybenzoic acid. GPC, IR, and 1H‐NMR analyses revealed that a low‐polydispersity macromonomer of PCL with the desired cyclohexene oxide (CHO) functionality at the mid‐chain was obtained. The photoinduced cationic polymerizations of this macromonomer yielded comb‐shaped and graft copolymers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Lewis acid mediated polymerization of poly(dimethylsiloxane) polymers: Investigating reaction kinetics using both NMR spectroscopy and cyclic voltammetry
Authors: Apedaile Alistair , Liggat John , Parkinson John , Nikiforidis George , Berlouis Leonard , Patel Mogon
Published: September 2011

Bulk condensation polymerization of (dimethylmethoxy)‐m‐carborane and (dichlorodimethyl)silane occurs in the presence of an Mx+Clx Lewis acid catalyst. In the literature, FeCl3 is commonly used as the catalyst of choice but little is known about the activation energy and entropy of this polymerization. By monitoring using 1H‐NMR the reaction of a methoxy‐terminated poly(dimethylsiloxane) and (dichlorodimethyl)silane the rate determining step in the FeCl3 catalyzed system is determined. The activation energy was calculated to be +43.6 kJ mol−1 and the entropy of the reaction was also calculated. The calculated large entropy of reaction indicates that the transition step is highly ordered. The formation of the electrophile intermediate species in the first step of the reaction has also been investigated using cyclic voltammetry. To the cyclic voltammetry data Randles‐Sevcik fits have been applied to the oxidation peaks to determine the diffusion coefficients for the oxidation of Fe2+ to Fe3+. Also, the initial prediction of a reversible reaction Step 1 was shown to be incorrect as the normalized reduction peak maxima increase with scan rate, indicative of an electron transfer‐chemical reaction mechanism. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of biodegradable polymers by inverse gas chromatography. III. Blends of amylopectin and poly(L‐lactide)
Authors: Zhong Bihuan , Al‐Saigh Zeki Y.
Published: September 2011

The morphology changes and surface thermodynamics of blends of amylopectin (AP)–poly(L‐lactide) (PLA) were investigated over a wide range of temperatures and compositions using the inverse gas chromatography method. Twenty‐five solutes were selected such as alkanes, acetates, oxy, halogenated, and six‐member ring families. They provided a variety of specific interactions with the blends' surface. The morphology showed two regions, some others showed a de‐polymerization above 130°C. These zones enabled the estimation of Tg and Tm of AP, PLA, and the blends. Blending AP with PLA caused a decrease in AP's Tg value due to the reduction of the degree of crystallinity of the blend. Exothermic values of χ23 were obtained indicating the compatibility of AP and PLA at all temperatures and weight fractions of AP–PLA. The miscibility was favored at 75%AP, only 25%AP–75%PLA composition influenced the degree of crystallinity. The dispersive component of the surface energy of the blends ranged from 16.09 mJ/m2 for the pure AP as high as 58.36 mJ/m2 at 110°C when AP was mixed with PLA in a 50–50% ratio. The surface energy was at its highest value when the composition was 75% of AP, in good agreement with χ23 values. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Hyperbranched PEI grafted by hydrophilic amino acid segment poly[N‐(2‐hydroxyethyl)‐L‐glutamine] as an efficient nonviral gene carrier
Authors: Chen Jie , Tian Huayu , Guo Zhaopei , Lin Lin , Dong Xuan , Zhu Xiaojuan , Chen Xuesi
Published: September 2011

A polyethylenimine‐poly(hydroxyethyl glutamine) copolymer (PEI‐PHEG) was designed and synthesized as a gene delivery system. The molecular structure of PEI‐PHEG was characterized using nuclear magnetic resonance. Moreover, PEI‐PHEG/pDNA complexes were fabricated and characterized by gel retardation assay, particle size analysis, and zeta potential analysis. The transfection efficiency and cytotoxicity of PEI‐PHEG were evaluated using human cervical carcinoma (HeLa), human embryonic kidney (HEK293), and murine colorectal adenocarcinoma (CT26) cells in vitro. The results show that PEI‐PHEG could effectively form positively charged nano‐sized particles with pDNA; the particle size was in a range of 130.2 to 173.0 nm and the zeta potential was in a range of 27.6 to 41.0 mV. PEI‐PHEG exhibited much lower cytotoxicity and higher gene transfection efficiency than PEI‐25K with different cell lines in vitro. An animal test was also conducted on a Lewis Lung Carcinoma tumor model in C57/BL6 mice by using subcutaneous intratumoral administration. The results show that in vivo transfection efficiency of PEI‐PHEG was improved greatly compared with that of commercial PEI‐25K. These results demonstrate that PEI‐PHEG can be a potential nonviral vector for gene delivery systems both in vitro and in vivo. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Characterization of the mechanical properties, crystallization, and enzymatic degradation behavior of poly(butylene succinate‐co‐ethyleneoxide‐co‐DL‐lactide) copolyesters
Authors: Tan Licheng , Chen Yiwang , Zhou Weihua , Nie Huarong , Ye Suwen
Published: September 2011

A series of aliphatic biodegradable poly (butylene succinate‐co‐ethyleneoxide‐co‐DL‐lactide) copolyesters were synthesized by the polycondensation in the presence of dimethyl succinate, 1,4‐butanediol, poly(ethylene glycol), and DL‐oligo(lactic acid) (OLA). The composition, as well as the sequential structure of the copolyesters, was carefully investigated by 1H‐NMR. The crystallization behaviors, crystal structure, and spherulite morphology of the copolyesters were analyzed by differential scanning calorimetry, wide angle X‐ray diffraction, and polarizing optical microscopy, respectively. The results indicate that the sequence length of butylene succinate (BS) decreased as the OLA feed molar ratio increasing. The crystallization behavior of the copolyesters was influenced by the composition and sequence length of BS, which further tuned the mechanical properties of the copolyesters. The copolyesters formed the crystal structures and spherulites similar to those of PBS. The incorporation of more content of ethylene oxide (EO) units into the copolyesters led to the enhanced hydrophilicity. The more content of lactide units in the copolyesters facilitated the degradation in the presence of enzymes. The morphology of the copolyester films after degradation was also studied by the scanning electron microscopy. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis and characterization of chitosan/cloisite 30B film for controlled release of ofloxacin
Authors: Sahoo Debasish , Nayak P. L.
Published: September 2011

In this research program, chitosan film was prepared by blending chitosan with Cloisite 30 B at different concentrations 0 wt %, 1 wt %, and 2.5 wt %. The blends were characterized by Fourier transmission infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X‐ray diffraction (XRD) analysis. From the FTIR spectra the various groups present in chitosan/C 30 B blend were monitored. The homogeneity, morphology, and crystallinity of the blends were ascertained from SEM and XRD data, respectively. The most suitable form of blend was taken and used as a carrier for the controlled release of ofloxacin. The swelling studies have been carried out at different drug loading. Drug release kinetics was analyzed by plotting the cumulative release data versus time by fitting to an exponential equation which indicated the occurrence of non‐Fickian type of kinetics. The drug release was investigated at different pH medium and it was found that the drug release depends upon the pH medium as well as the nature of matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Synthesis of a branched poly(phenylene ethylene) with bromomethyl groups as an organosoluble and functional parylene
Authors: Kobayashi Ataru , Sumi Kentaro , Konishi Gen‐ichi
Published: September 2011

We synthesized a branched poly(phenylene ethylene) (BPPE) with bromomethyl groups from 1,3,5‐tris(bromomethyl)benzene derivatives via the Wurtz coupling reaction. In the case of 1,3,5‐tris(bromomethyl)‐2,4,6‐trimethoxybenzene as a monomer, the obtained polymer (Mn = 6100, Mw/Mn = 1.9) had bromomethyl groups. The 1HNMR analysis showed that a very large number of unreacted bromomethyl groups (Ph‐CH2Br) remained in the BPPE; the reaction of this polymer with phenolic hydroxyl groups proceeded quantitatively. This suggested that BPPEs can be functionalized using unreacted bromomethyl groups, making them a very attractive starting point for the creation of functionalized BPPEs with further enhanced processability. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Analysis of tensile modulus of PP/nanoclay/CaCO3 ternary nanocomposite using composite theories
Authors: Zare Yasser , Garmabi Hamid
Published: September 2011

The tensile modulus of PP/nanoclay/CaCO3 hybrid ternary nanocomposite was analyzed using composite models. Rule of mixtures, inverse rule of mixtures, modified rule of mixtures (MROM), Guth, Paul, Counto, Hirsch, Halpin–Tsai, Takayanagi, and Kerner–Nielsen models were developed for three‐phase system containing two nanofillers. Among the studied models, inverse rule of mixtures, Hirsch, Halpin–Tsai, and Kerner–Nielsen models calculated the tensile modulus of PP/nanoclay/CaCO3 ternary nanocomposite successfully compared with others. Furthermore, the Kerner–Nielsen model was simplified to predict the tensile modulus by volume fractions of nanofillers. Also, Takayanagi model was modified for the current ternary system. The developed Takayanagi model can predict the tensile modulus using Young's modulus and volume fractions of matrix and nanofillers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Studies on the self‐assembly behavior of the hydrophobically associating polyacrylamide
Authors: Chen Hong , Ye Zhongbin , Han Lijuan , Luo Pingya
Published: September 2011

Contrasted with partially hydrolyzed polyacrylamide (HPAM), the self‐assembly behavior and microstructure of hydrophobically associating polyacrylamide (HAPAM) in aqueous solution have been studied by means of fluorescence spectrum, transmission electron microscopy (TEM), atomic force microscope (AFM), and apparent viscosity test in this article. The fluorescent probe analysis indicates that the HAPAM molecules will form associating aggregates in pure water. The results show that HAPAM can easily self‐assemble to form an aggregate by hydrophobic driving force in dilute aqueous solution. The association of hydrophobic groups of the HAPAM causes the formation of supermolecule, so there are associating aggregates formed at very low concentration and then leads to the formation of network at a higher concentration. TEM and AFM measurements show that a distinct network structure has been formed in 1000 mg L−1 of HAPAM solution, indicating the strong association of hydrophobic groups. These results are consistent with the viscosity measurement and reveal that the excellent viscosification of HAPAM is due to the association of hydrophobic groups in the aqueous solution. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Improving the magnetorheological properties of polyurethane magnetorheological elastomer through plasticization
Authors: Wu Jinkui , Gong Xinglong , Fan Yanceng , Xia Hesheng
Published: September 2011

The highly filled anisotropic polyurethane (PU) magnetorheological elastomers (MREs) were prepared through an in‐situ one‐step polycondensation process under a magnetic field. The carbonyl iron formed chain‐like structure, which was fixed in the PU matrix. The plasticizer diisooctyl phthalate (DOP) was incorporated into PU to soften the matrix and improve the MR effect. The influence of DOP on the microstructure and properties of PU MREs were investigated. The incorporation of DOP reduced the viscosity of the prepolymer and made the carbonyl iron align more easily in the PU matrix. The aligned chain‐like structure of carbonyl iron in PU greatly enhanced the thermal conductivity and the compressive properties of PU MREs. The incorporation of DOP reduced the modulus of PU MREs and the glass transition temperature of the soft segments of PU. But highly filled carbonyl iron and DOP led to a decrease in the thermal stability to some extent. The MR test showed that DOP plasticization significantly enhanced both absolute and relative MR effect simultaneously. With 70 wt% carbonyl iron and 15 wt% DOP (the weight ratio of Fe: PU: DOP is 70 : 15: 15), the absolute and relative MR effects of anisotropic PU MREs were ∼ 1.16 MPa and ∼ 386.7%, ∼ 3.5 and ∼ 58 times of the PU MRE without the plasticizer at the same iron content. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Novel poly‐bridged‐naphthalene with blue‐light‐emitting property via electropolymerization
Authors: Zhu Guang , Xu Jingkun , Yue Ruirui , Lu Baoyang , Hou Jian
Published: September 2011

Relatively scant work was related to polynaphthalene (PN) and its derivatives because of the unique nonlinear optical properties which make PN and its derivatives owning potential applications in various domains. According to relevant studies, the pursuit for the synthesis of high quality PN films is a great challenge for the applications of PN. To achieve high quality polymer films, three bridged naphthalene derivatives were designed, and finally two crosslinked PN exhibiting space network were electrosynthesized, respectively, by direct anodic oxidation from 1,6‐bis(naphthalen‐2‐yloxy)hexane and 1,4‐bis((naphthalen‐2‐yloxy)methyl)benzene in mixed electrolyte of dichloromethane containing boron trifluoride diethyl etherate. Furthermore, as‐formed conducting films were characterized by cyclic voltammetry, spectroscopic analysis, thermal analysis, and scanning electron microscopy. And the series of characterizations indicated that films hold high stability and good blue‐light‐emitting property. Meanwhile, these polymer films were smooth, shiny, and flexible easily being processed into various shapes by conventional mechanical methods. Consequently, these high quality PN films will facilitate their potential applications as blue‐light‐emitting materials in organic light‐emitting diode. Because di(naphthalen‐2‐yl) terephthalate was difficult to electropolymerize, the effects of bridged spacers to polymerization were also discussed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Properties and structural characterization of oxide starch/chitosan/graphene oxide biodegradable nanocomposites
Authors: Ma Jun , Liu Changhua , Li Rui , Wang Jia
Published: September 2011

Novel chitosan (CS)/oxidized starch (OST)/graphene oxide (GO) nanocomposites (COST/GO‐n) films are prepared in a casting and solvent evaporation method. Fourier transform infrared spectroscopy, X‐ray diffractions, atomic force microscopy, scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, tensile testing, and moisture uptake are used to study the structure and properties of these nanocomposites. To indicate the effect of carboxyl groups of OST, some results of the properties of CS/starch/GO nanocomposite (CST/GO‐n) were selected for control experimentation. Compared with the control CST/GO‐n series, COST/GO‐n films, which have the same component ration showed higher tensile strength (σb) and lower elongation at break (εb). Additionally, in the COST/GO‐n series, the σb increased with an increase of GO loading. However, higher proportion of GO could result in aggregations of GO nanosheets and deterioration of the film properties. Compared with the COST/GO‐0, the values of σb and water resistance of the COST/GO‐4 containing 2.0 wt % of GO were improved by 57.7 and 20.1%, respectively. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Study of compostable behavior of jute nano fiber reinforced biocopolyester composites in aerobic compost environment
Authors: Maiti Sonakshi , Ray Dipa , Mitra Debarati , Misra Manjusri
Published: September 2011

Jute nano fiber (JNF) reinforced biocopolyester‐based composite sheets were prepared with 2% and 10 wt % filler loading and compostability tests were performed in simulated aerobic compost environment at ambient temperature for a period of 50 days. Weight loss study revealed that the incorporation of JNF enhanced the rate of degradation significantly. The unreinforced sample exhibited a steady loss in weight, whereas, the JNF reinforced samples showed three phase degradation. They had a steady weight loss up to 30 days followed by a plateau zone between 30 and 40 days and after that, there was again an increase in weight loss up to 50 days. The biodegraded samples were investigated for their change in molecular weight by Gel Permeation Chromatography (GPC). The change in structure was examined by Differential Scanning Calorimetry (DSC) and morphological change was observed by Scanning Electron Microscopy (SEM). Molecular weight study revealed the fact that Biocopolyester molecules had a significant breakdown in chain length during melt mixing with 10 wt % JNF, which was much less predominant in 2 wt % JNF loaded composites. Such a decrease in chain length and presence of 10 wt % JNF might have facilitated the biodegradation process resulting in highest weight loss. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Frequency response analysis of nonisothermal film blowing process using transient simulations
Authors: Kim Hyung Min , Sung Lee Joo , Jung Hyun Wook , Hyun Jae Chun
Published: September 2011

Frequency response of the nonisothermal viscoelastic film blowing process to the ongoing sinusoidal disturbances has been investigated using transient simulation techniques. Of the many state variables exhibiting resonant peaks with the input frequency, amplitude ratio of the film cross‐sectional area at the freezeline height has been used as an indicator of the process sensitivity. The effects of operating conditions and viscoelasticity on the sensitivity have been scrutinized around the middle point of three multiple steady states under the given conditions. The sensitivity results have been interpreted through their correlation with results from linear stability analysis. Increasing draw ratio generally makes the system more sensitive to sinusoidal disturbances, whereas the cooling induces more sensitive or less sensitive system, according to the location of a steady state. Also, the viscoelasticity makes the system of extensional thickening fluids more sensitive at low Deborah number and less sensitive at high Deborah number. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Evaluation of Anti‐inflammatory, Anti‐nociceptive, and Anti‐ulcerogenic Activities of Novel Synthesized Thiazolyl and Pyrrolyl Steroids
Authors: Mohareb Rafat M. , Elmegeed Gamal A. , Baiuomy Ayman R. , Eskander Emad F. , William Marian G.
Published: September 2011

Developing new therapeutic agents that can overcome gastrointestinal injury and at the same time could lead to an enhanced anti‐inflammatory effect becomes an urgent need for inflammation patients. Thiazolyl and pyrrolyl steroids were synthesized via straight forward and efficient methods and their structures were established based on their correct elemental analysis and compatible IR, 1H‐NMR, 13C‐NMR, and mass spectral data. The dihydrothiazolyl‐hydrazonoprogesterone 12 and the aminopyrrolylprogesterone 16a showed anti‐inflammatory, antinociceptive, and anti‐ulcerogenic activity with various intensities. Edema were significantly reduced by both doses of tested compounds (25 and 50 mg/kg) at 2, 3, and 4 h post‐carrageenan. The high dose of compound 16a was the most effective in alleviating thermal pain. Gastric mucosal lesions, caused in the rats by the administration of ethanol or indomethacin (IND), were significantly inhibited by each of the two tested compounds. These results provide a unique opportunity to develop new anti‐inflammatory drugs which devoid the ulcerogenic liabilities associated with currently marketed drugs.
Emphasizing social features in information portals: Effects on new member engagement
Authors: Sharma Nikhil , Butler Brian S. , Irwin Jeannie , Spallek Heiko
Published: September 2011

Many information portals are adding social features with hopes of enhancing the overall user experience. Invitations to join and welcome pages that highlight these social features are expected to encourage use and participation. While this approach is widespread and seems plausible, the effect of providing and highlighting social features remains to be tested. We studied the effects of emphasizing social features on users' response to invitations, their decisions to join, their willingness to provide profile information, and their engagement with the portal's social features. The results of a quasi‐experiment found no significant effect of social emphasis in invitations on receivers' responsiveness. However, users receiving invitations highlighting social benefits were less likely to join the portal and provide profile information. Social emphasis in the initial welcome page for the site also was found to have a significant effect on whether individuals joined the portal, how much profile information they provided and shared, and how much they engaged with social features on the site. Unexpectedly, users who were welcomed in a social manner were less likely to join and provided less profile information; they also were less likely to engage with social features of the portal. This suggests that even in online contexts where social activity is an increasingly common feature, highlighting the presence of social features may not always be the optimal presentation strategy.