bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of copolymer composition on the surface properties of perfluoroalkylethyl acrylates
Authors: Youssef Ali , Pabon Martial , Severac Romain , Gilbert Robert G. 
Published: August 2009

AbstractThe surface properties of two perfluoroalkylethyl acrylic copolymers—aqueous, Zonyl®329 and solvent‐based, Zonyl®225—were studied. Zonyl®329 is a water‐based dispersion and Zonyl®225 a solvent‐based copolymer solution; both polymers have the same perfluoroalkyethyl side chains [F(CF2)nCH2CH2] but have different comonomer compositions. Thin films, prepared by dip coating onto mica and quartz, with and without annealing, were characterized by contact angle and by X‐ray photoelectron spectroscopy (XPS). The contact angle measurements showed little variation with polymer and with substrate, consistent with the supposition that the perfluoroalkylethyl chains aggregate on the surface and thus dominate surface properties, irrespective of the composition of the rest of the polymer. XPS revealed only small variations in surface chemistry for studied films. Annealed films showed improved segregation for solvent‐based Zonyl®225, which has both hydrocarbon alkyl and perfluoroalkylethyl side chains; the presence of hydrocarbon alkyl chains enables the perfluoroalkylethyl chains to reorganize after annealing. Depending on the external conditions, this thermal treatment can enable more perfluoroalkylethyl chains to reach the film surface (solid/air interface), leading to a reduction in the dispersive‐dominant surface and enhancement in perfluoroalkylethyl segregation. This suggested that perfluoroalkylethyl side chains dominate the surface properties, which are thus not dependent on substrate, backbone composition, or formulation. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
N2‐filled hollow glass beads as novel gas carriers for microcellular polyethylene
Authors: Dong Lijie , Huang Jing , Li Rui , Zhang Yi , Pan Minxuan , Xiong Chuanxi 
Published: August 2009

AbstractN2‐filled hollow glass beads (HGB) were first used as novel gas carriers to prepare microcellular polymers by compression molding. Dicumyl peroxide was acted as crosslink agent to control the produced microcellular structure of low density polyethylene (LDPE)/HGB. The effect of temperature, pressure and the content of gel on the embryo‐foaming, and final‐foaming structure are investigated. Scanning electronic microscopy shows that the average cell size of microcellular LDPE ranges from 0.1 to 10 μm, and the foam density is about 109–1011 cells/cm3. A clear correlation is established between preserving desirable micromorphologies of microcellular LDPE in different processing stage and tuning processing factors. The pertinent foaming mechanism of microcellular materials foamed with HGB is proposed. Because of the good mechanical strength, low density, weak water‐absorption, and excellent heat insulate ability, microcellular LDPE has great potential application in energy building materials. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electrospun poly(D,L‐lactide) fibers for drug delivery: The influence of cosolvent and the mechanism of drug release
Authors: Xie Zhiwei , Buschle‐Diller Gisela 
Published: August 2009

AbstractControlled‐drug release from electrospun fibers has found important biomedical applications in wound healing, transdermal delivery, and tissue engineering. In this study, poly(D,L‐lactide) (PDLLA) was electrospun into ultrafine fibers and loaded with tetracycline (TC) or chlorotetracycline (CTC) as model drugs. The influence of a cosolvent (methanol) at various concentrations was studied regarding physical properties, morphology, and in vitro release profiles of the drugs from the PDLLA nanofibers. Swelling tests in a physiological buffer solution were performed to determine the extent and rate of swelling of the fiber mats. The results showed that for both drugs electrospun fiber diameters decreased with increasing amounts of cosolvent, whereas water contact angles and drug‐loading efficiency increased. However, similar in chemical structure, the two drugs exhibited considerably different release mechanisms. The results indicated that the concentration of methanol changed the release profiles mainly based on the morphology of the resultant nanofibers and the polymer/drug/solvent interaction during the electrospinning and drug release process. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of amphiphilic phenyl–polysucrose microspheres for protein adsorption
Authors: Wang Xiukui , Hou Xin , Wu Yichun , You Shishu 
Published: August 2009

AbstractIn this study, we prepared novel amphiphilic phenyl–polysucrose microspheres by a two‐step pathway. Crosslinked polysucrose microspheres were synthesized with soluble polysucrose and epichlorohydrin by inversed suspension polymerization first. Then, phenyl–polysucrose microspheres were obtained through the reaction between the polysucrose microspheres and glycidyl phenyl ether. Fourier transform infrared spectrometry and X‐ray photoelectron spectroscopy proved that the microspheres had both hydroxyl groups and phenyl ligands. The quantitative determination of the phenyl groups indicated the optimal conditions for synthesis of the phenyl–polysucrose microspheres. The properties of the phenyl–polysucrose beads showed that the dry density increased from 1.38 to 2.29 g/mL, the equilibrium water content decreased from 77.30 to 33.68%, and the hydroxyl content remained at about 41.70 mmol/g when the phenyl content was increased from 0.00 to 2.64 mmol/g. The results of protein adsorption showed that the saturated adsorption capacities of the phenyl–polysucrose microspheres increased with increasing ion strength compared with the polysucrose microspheres. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electrochemical synthesis of polypyrrole layers doped with glutamic ions
Authors: Meteleva‐Fischer Yulia V. , Von Hauff Elizabeth , Parisi Jürgen 
Published: August 2009

AbstractElectrochemically synthesized polypyrrole thin films doped with glutamic ions were investigated as interesting materials for potential use as molecularly selective surfaces. Pyrrole and glutamate interact in aqueous solution, resulting in the formation of a prominent band at 240 nm in the absorption spectra of the solution. This feature was assigned to the formation of a complex, which significantly influences the electrochemical deposition of polypyrrole films doped with glutamate. It was also detected that oxidation of these complexes leads to the appearance of a shoulder in the absorption spectrum at 270 nm, which corresponds to the yellowish color of pyrrole aged under influence of air. A mechanism is proposed for polymer film growth in aqueous solutions containing monosodium L‐glutamate and pyrrole. It takes into account the observed influence of the pH of the solution, the concentration of reagents, the zwitterionic properties of glutamate on deposition, and results from spectroscopic measurements. It is also shown that glutamic ions can electrochemically be released from the synthesized polymer layers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Rheology and viscosity scaling of the polyelectrolyte xanthan gum
Authors: Wyatt Nicholas B. , Liberatore Matthew W. 
Published: August 2009

AbstractThe viscosity as a function of concentration for xanthan gum in both salt‐free solution and in 50 mM NaCl is measured and compared with a scaling theory for polyelectrolytes. In general, the zero shear rate viscosity and the degree of shear thinning increase with polymer concentration. In addition, shear thinning was observed in the dilute regime in both solvents. In salt‐free solution, four concentration regimes of viscosity scaling and three associated critical concentrations were observed (c* ≈ 70 ppm, ce ≈ 400 ppm, and cD ≈ 2000 ppm). In salt solution, only three concentration regimes and two critical concentrations were observed (c* ≈ 200 ppm and ce ≈ 800 ppm). In the presence of salt, the polymer chain structure collapses and occupies much less space resulting in higher values of the critical concentrations. The observed viscosity‐concentration scaling is in very good agreement with theory in the semidilute unentangled and semidilute entangled regimes in both salt‐free and 50 mM NaCl solution. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Crosslinking and thermal stability of thermosets based on novolak and melamine
Authors: Dante Roberto C. , Santamaria Diego A. , Gil Jesús Martín 
Published: August 2009

AbstractThe crosslinking under pressure of a mixture of novolak with melamine resin has been investigated by means of several techniques, including differential scanning calorimetry, thermal gravimetric analysis, X‐ray diffraction, and infrared spectroscopy. The crosslinking of the mixture essentially follows two steps. The former occurs at 150°C and leads to resin networks composed of di‐ and trisubstituted phenols without significant reaction with melamine polymers. The latter, at 200°C, mainly involves the direct crosslinking of melamine polymers with disubstituted phenols. High pressure, applied to the reaction cell, slows down the crosslinking extent, by inhibiting the formation of trisubstituted phenols. This is probably due to the formation of gaseous by‐products of crosslinking. Moreover, a certain structuring effect due to high pressure was observed by means of X‐ray diffraction.© 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Using T‐PODs to assess variations in the occurrence of coastal bottlenose dolphins and harbour porpoises
Authors: Bailey Helen , Clay Gemma , Coates Elizabeth A. , Lusseau David , Senior Bridget , Thompson Paul M. 
Published: August 2009

Abstract
Assessments of anthropogenic impacts on cetaceans are often constrained by limited data on the extent to which these species use particular areas.
Timing porpoise detectors (T‐PODs) are autonomous data recorders for detecting cetacean echolocation clicks, potentially providing cost‐effective opportunities for monitoring cetacean occurrence.
The performance of T‐PODs was assessed in three areas off the Scottish east coast, where the relative occurrence of bottlenose dolphins and harbour porpoises was known to differ. Land‐based observations in one area compared visual and acoustic detections of dolphins, while direct hydrophone recordings of dolphin echolocation clicks were compared with T‐POD detections during boat surveys.
Land‐based surveys recorded 89 groups of dolphins within 900 m of the T‐POD. All groups spending >30 min in the area were detected on the T‐POD, and the probability of detection declined in relation to distance from the recording site.
The number of dolphin clicks recorded on the independent hydrophone system was significantly related to the number detected by a T‐POD. Between pairs of T‐PODs, there was also significant correlation with the numbers of clicks recorded in each hour, both for channels set to detect bottlenose dolphins and for channels set to detect harbour porpoises.
Year‐round deployments of paired T‐PODs detected significant geographical variation in detections for both bottlenose dolphins and harbour porpoises. This pattern reflected published data from visual surveys, where dolphins occurred most regularly within the Moray Firth Special Area of Conservation, and porpoises were sighted more regularly in offshore waters.
T‐PODs do not detect all cetaceans in the area, and care must be taken when interpreting data from mixed species communities. Nevertheless, these results confirm that T‐PODs provide an effective method for monitoring the occurrence of bottlenose dolphins and harbour porpoises, and provide excellent potential for collecting baseline data from poorly studied areas and monitoring long‐term temporal change in key areas of interest. Copyright © 2009 John Wiley & Sons, Ltd.
When forewarning backfires: Paradoxical effects of elaborating social feedback on entrapment in a losing course of action
Authors: Schulz‐Hardt Stefan , Vogelgesang Frank , Pfeiffer Felix , Mojzisch Andreas , Thurow‐Kröning Birgit 
Published: August 2009

AbstractEntrapment occurs if people persist with losing courses of action. In two experiments, we show how elaborating social feedback (i.e., premature praise or forewarning regarding the chosen course of action) can have paradoxical effects on entrapment. The participants acted as head of a translation department and had to choose one out of four possible translation strategies for their employees. After choosing, they read four arguments (presumably written by former participants) which were either all in favor of the strategy chosen, all against it, or mixed. Half of the participants only read these arguments, whereas the other half elaborated on them by providing written comments (Experiment 1). The results showed that elaborating on other persons' arguments led to stronger entrapment, independently of whether the arguments were positive or negative. This pattern was due to biased argument processing: Whereas confirming thoughts were generated for positive arguments, negative arguments were refuted. Experiment 2 confirmed that this biased argument processing caused subsequent entrapment. These results indicate that elaborating any type of argument can lead to heightened entrapment and, hence, forewarning can backfire. Copyright © 2009 John Wiley & Sons, Ltd.
Possible amelioration of atherogenic diet induced dyslipidemia, hypothyroidism and hyperglycemia by the peel extracts of Mangifera indica, Cucumis melo and Citrullus vulgaris fruits in rats
Authors: Parmar Hamendra Singh , Kar Anand 
Published: August 2009

AbstractHitherto unknown efficacy of the peel extracts of Mangifera indica (MI), Cucumis melo (CM) and Citrullus vulgaris (CV) fruits in ameliorating the diet‐induced alterations in dyslipidemia, thyroid dysfunction and diabetes mellitus have been investigated in rats.In one study, out of 4 different doses (50–300 mg/kg), 200 mg/kg of MI and 100 mg/kg for other two peel extracts could inhibit lipidperoxidation (LPO) maximally in liver. In the second experiment rats were maintained on pre‐standardized atherogenic diet CCT (supplemented with 4 % cholesterol, 1% cholic acid and 0.5% 2‐thiouracil) to induce dyslipidemia, hypothyroidism and diabetes mellitus and the effects of the test peel extracts (200 mg/kg of MI and 100 mg/kg for CM and CV for 10 consecutive days) were studied by examining the changes in tissue LPO (in heart, liver and kidney), concentrations of serum lipids, thyroid hormones, insulin and glucose. Rats, treated simultaneously with either of the peel extracts reversed the CCT‐diet induced increase in the levels of tissue LPO, serum lipids, glucose, creatinine kinase‐MB and decrease in the levels of thyroid hormones and insulin indicating their potential to ameliorate the diet induced alterations in serum lipids, thyroid dysfunctions and hyperglycemia/diabetes mellitus.A phytochemical analysis indicated the presence of a high amount of polyphenols and ascorbic acid in the test peel extracts suggesting that the beneficial effects could be the result of the rich content of polyphenols and ascorbic acid in the studied peels.
Auraptene, a citrus fruit compound, regulates gene expression as a PPARα agonist in HepG2 hepatocytes
Authors: Takahashi Nobuyuki , Kang Min‐Sook , Kuroyanagi Kayo , Goto Tsuyoshi , Hirai Shizuka , Ohyama Kana , Lee Joo‐Young , Kawada Teruo , Yu Rina , Yano Masamichi , Sasaki Takao , Murakami Shigeru 
Published: August 2009

AbstractCitrus fruit compounds have various activities that improve pathological conditions in many tissues. In this study, we examined the effect of auraptene contained mainly in the peel of citrus on peroxisome proliferator‐activated receptor‐α (PPARα) activation. To examine effects of auraptene on the PPARα activation in hepatocytes, PPAR ligand assay system was developed using HepG2 hepatocytes, in which the endogenous PPARα expression level is very low. In the PPAR ligand assay, the addition of auraptene showed significant effects on the transactivation of GAL4/PPARα chimera proteins in a dose‐dependent manner. Actually, treatment with auraptene induced the up‐regulation of PPAR target genes, such as acyl‐CoA oxidase (ACO), carnitine‐palmitoyl transferase 1A (CPT1A) and acyl‐CoA synthetase (ACS), in PPARα‐expressing HepG2 hepatocytes. The regulation of gene expression was dependent on PPARα because mock‐transfected HepG2 hepatocytes showed no regulation. The up‐regulation of PPAR target gene expression by auraptene was sufficient to enhance oleic acid uptake into PPARα‐expressing HepG2 hepatocytes. These results indicate that auraptene acts as a PPARα agonist in hepatocytes and that auraptene may improve lipid abnormality through PPARα activation in the liver.
Lipid profile lowering effect of SoyproTM fermented with lactic acid bacteria isolated from Kimchi in high‐fat diet‐induced obese rats
Authors: Kim Na‐Hyung , Kim Hyung‐Min , An Hyo‐Jin , Um Jae‐Young , Moon Phil‐Dong , Kim Su‐Jin , Choi In‐Young , Hong Seung‐Heon , Myung Noh‐Yil , Jeong Hyun‐Ja 
Published: August 2009

AbstractLactic acid bacteria are known to exert various physiologic functions in humans. In the current study, we investigated the effects of SoyproTM, a new soymilk fermented with lactic acid bacteria, like Leuconostoc kimchii, Leuconostoc citreum, and Lactobacillus plantarum, isolated from Kimchi, on adipocyte differentiation in preadipocyte 3T3‐L1 cell lines and weight gain or the plasma lipid profile in Sprague‐Dawley rats. Adipocyte 3T3‐L1 cells treated with SoyproTM (10 μg/ml) significantly reduced the contents of cellular triglyceride and inhibited cell differentiation by Oil red O staining. Treatment with SoyproTM (10 μg/ml) for an additional two days in adipocytes inhibited the expression of peroxisome proliferator‐activated receptor‐μ2 and CCAAT/enhancer binding protein‐α, transcription factors of adipocyte differentiation. Based on these in vitro studies, we examined the anti‐obesity effect of SoyproTM in rats for six weeks. SoyproTM had no significant effect on high‐fat diet‐induced increases in body weight, food intake, or feed gain ratio. However, the administration of SoyproTM significantly reduced the concentration of the plasma low density lipoprotein cholesterol. Changes in the plasma levels of total cholesterol and glucose were inclined to decrease in SoyproTM administrated groups compared with saline treated group. Triglyceride and high density lipoprotein cholesterol values in SoyproTM fed groups were similar compared to those of saline fed groups. Although further research is needed, these findings suggest that SoyproTM decreased the levels of low density lipoprotein cholesterol in high‐fat diet‐induced obesity and might partially inhibit the adipocyte differentiation through the suppression of a transcription factors peroxisome proliferator‐activated receptor‐μ2 and CCAAT/enhancer binding protein‐α.
Low serum α‐tocopherol and selenium are associated with accelerated apoptosis in severe sepsis
Authors: Weber Stefan U. , Lehmann Lutz Eric , Schewe Jens‐Christian , Schröder Stefan , Book Malte , Hoeft Andreas , Stüber Frank , Thiele Jens T. 
Published: August 2009

AbstractDuring sepsis, a severe systemic disorder, micronutrients often are decreased. Apoptosis is regarded as an important mechanism in the development of often significant immunosuppression in the course of the disease. This study aimed to investigate a‐tocopherol and selenium in reference to apoptosis in patients with sepsis. 16 patients were enrolled as soon as they fulfilled the criteria of severe sepsis. 10 intensive care patients without sepsis and 11 healthy volunteers served as controls. a‐Tocopherol, selenium and nucleosomes were measured in serum. Phosphatidylserine externalization and Bcl‐2 expression were analyzed in T‐cells by flow cytometry. Serum α‐tocopherol and selenium were decreased in severe sepsis but not in non‐septic critically ill patients (p < 0.05). Conversely, markers of apoptosis were increased in sepsis but not in critically ill control patients: Nucleosomes were found to be elevated 3 fold in serum (p < 0.05) and phosphatidylserine was externalized on an expanded subpopulation of T‐cells (p < 0.05) while Bcl‐2 was expressed at lower levels (p < 0.05). The decrease of micronutrients correlated with markers of accelerated apoptosis. Accelerated apoptosis in sepsis is associated with low α‐tocopherol and selenium. The results support the investigation of micronutrient supplementation strategies in severe sepsis.
Matrine inhibits PMA‐induced MMP‐1 expression in human dermal fibroblasts
Authors: Jung Eunsun , Lee Jongsung , Huh Sungran , Lee Jienny , Hwang Hyunjin , Kim Youngsoo , Kim Yong‐Woo , Park Deokhoon , Yo Byun Sang 
Published: August 2009

AbstractMatrix metalloproteinase‐1 (MMP‐1) plays an important role in the maintenance and turnover of extracellular matrix (ECM) macromolecules. Remodelling of extracellular matrix by MMPs is a hallmark feature of physiological and pathological processes. In this study, in order to establish the therapeutic potential of matrine, we investigated its effect on MMP‐1 expression in human dermal fibroblast cells. We found that matrine inhibited both MMP‐1 mRNA and protein expression induced by PMA (phorbol myristate acetate). Therefore, we characterized the inhibitory mechanism of matrine on PMA‐induced MMP‐1 expression. Matrine inhibited PMA‐induced activation of the AP‐1 promoter, an important nuclear transcription factor in MMP‐1 expression. Additionally, we detected that matrine suppressed the PMA‐induced phosphorylation of two mitogen‐activated protein kinases, extracellular signal‐regulated protein kinase and c‐Jun N‐terminal kinase, but did not suppress the PMA‐induced phosphorylation of p38 kinase. These results suggest that matrine suppresses PMA‐induced MMP‐1 expression through inhibition of the AP‐1 signaling pathway and also may be beneficial for treatment of some inflammatory skin disorders.
Cigarette smoke effect on total salivary antioxidant capacity, salivary glutathione peroxidase and gamma‐glutamyltransferase activity
Authors: Greabu Maria , Totan Alexandra , Battino Maurizio , Mohora Maria , Didilescu Andreea , Totan Cosmin , Spinu Tudor 
Published: August 2009

AbstractSaliva is the first biological fluid that inhaled cigarette smoke (CS) encounters. CS contains several carcinogens known to initiate and promote tumourigenesis and metastasis. One of the aims of this study was to establish if glutathione peroxidase and gamma‐glutamyltranspherase (GGT) could be used as possible markers for evaluating the oral oxidative stress caused by smoking. The effect of CS on free radical generation was investigated using two methods. Using different assays, different antioxidants present in saliva may be evidenced due to the different principles on which they are based.Our results indicate that exposure to CS caused a statistically significant decrease of both salivary glutathione peroxidase (p < 0.01) and salivary GGT (p < 0.01).We also found that exposure to CS caused a statistically significant decrease of salivary total antioxidant status (p < 0.01). Such decreases may have a consistent role in the mechanisms by which the toxic effects of CS initiate oral inflammatory diseases, promote precancerous transformations, and destroy the oral cavity homeostasis. Therefore the evaluation of total antioxidant capacity of saliva is important but it must be done together with the evaluation of salivary specific markers of oxidative stress, such as uric acid, albumin and possibly, GGT.