bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative studies on the effects of casting solvent on physico‐chemical and gas transport properties of dense polysulfone membrane used for CO2/CH4 separation
Authors: Adewole Jimoh K. , Ahmad Abdul Latif , Ismail Suzylawati , Leo Choe Peng , Sultan Abdullah S. 
Published: April 2015

ABSTRACTThe effects of casting solvents on the physico–chemical and transport properties of polysulfone membranes were investigated. Comparative analysis of the properties of membranes prepared from a new solvent (diethylene glycol dimethyether, DEG) and other commonly used solvents (1‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, dimethyl sulfoxide and N,N‐dimethylformamide) were performed using gas permeation, X‐ray diffraction, scanning electron microscopy, thermogravimetric, and Fourier transform infrared spectroscopy analyses. The degree of polymer–solvent interaction was evaluated using the solvent molar volume, and Hansen and Flory–Huggins parameters. Membrane prepared from DEG displayed a relatively higher permeability of 29.08 barrer and CO2/CH4 selectivity of 23.12 compared to membranes prepared from other solvents. This improved performance was attributed to the better interaction between the DEG solvent and polysulfone than other solvents that were considered. DEG has the highest molar volume of 142.280 cm3/mol and the lowest Flory–Huggins parameter of 0.129. Thus a thorough evaluation of polymer–solvent interaction is very crucial in preparing membranes with optimum performance. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42205.
Structure and oxygen‐barrier properties of (linear low‐density polyethylene/ethylene–vinyl alcohol copolymer)/linear low‐density polyethylene composite films prepared by microlayer coextrusion
Authors: Su Huijun , Xue Juan , Cai Peiling , Li Jiang , Guo Shaoyun 
Published: April 2015

ABSTRACTEthylene–vinyl alcohol copolymer (EVOH) and linear low‐density polyethylene (LLDPE) blends with 5% LLDPE grafted with 1% maleic anhydride (MAH; EVOH/LLDPE/LLDPE‐g‐MAH), created to increase the interfacial compatibility, were coextruded with pure LLDPE through the microlayer coextrusion technology. The phase morphology and gas‐barrier properties of the alternating‐layered (EVOH/LLDPE/LLDPE‐g‐MAH)/LLDPE composites were studied by scanning electron microscopy observation and oxygen permeation coefficient measurement. The experimental results show that the EVOH/LLDPE/LLDPE‐g‐MAH and LLDPE layers were parallel to each other, and the continuity of each layer was clearly evident. This structure greatly decreased the oxygen permeability coefficient compared to the pure LLDPE and the barrier percolation threshold because of the existence of the LLDPE/EVOH/LLDPE‐g‐MAH blend layers, and the LLDPE layers diluted the concentration of EVOH in the whole composites. In addition, the effects of the layer thickness ratio of the EVOH/LLDPE/LLDPE‐g‐MAH and LLDPE layers and the layer number on the barrier properties of the layered composites were investigated. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42211.
Synthesis and characterization of star‐shaped PLLA with sorbitol as core and its microspheres application in controlled drug release
Authors: Teng Lijing , Nie Wangyan , Zhou Yifeng , Song Linyong , Chen Pengpeng 
Published: April 2015

ABSTRACTThe purpose of this study was to investigate the suitability of a six‐arm star‐shaped poly(l‐lactide)s (s‐PLLA) as controlled drug carriers for hydrophobic drug molecules. First, s‐PLLA was synthesized by ring‐opening polymerization of l‐lactide using sorbitol as initiator and stannous octoate as catalyst. The structure and molecular weight (Mw) of s‐PLLA was characterized with 1H NMR, 13C NMR, and GPC. Second, rifampicin (RIF) used as a model drug was encapsulated within the microspheres of s‐PLLA via oil‐in‐water emulsion/solvent evaporation technique. The morphology, drug encapsulation efficiency (EE), and in vitro release behavior of the prepared microspheres were studied in details. Results indicated that the average diameters of s‐PLLA microspheres can be controlled between 8 and 20 µm by varying the copolymer's concentration or Mw. The EE of RIF was mainly determined by the concentration of s‐PLLA. The in vitro study showed that the burst release behavior can be depressed by increasing the Mw of the s‐PLLA. Present work suggests that the synthesized s‐PLLA could be used as a new material for drug delivery. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42213.
Antimicrobial polyethylene wax emulsion and its application on active paper‐based packaging material
Authors: Xu Xiang , Zheng Anna , Zhou Xiaodong , Guan Yong , Pan Yuanfeng , Xiao Huining 
Published: April 2015

ABSTRACTAntimicrobial polyethylene wax (PEW) emulsions, prepared by emulsifying polyethylene wax grafted with polyhexamethylene guanidine hydrochloride (PEW‐g‐PHGH), were used as wet‐end additives or coating materials for fabricating hydrophobic and anti‐mold hand‐sheets or paper. To obtain PEW‐g‐PHGH, maleic anhydride (MAH) was adopted as a bridging agent. The melt or solution grafting of MAH to PEW was performed to achieve the appropriate grafting degree and grafting efficiency. The resulting PEW‐g‐PHGH was emulsified using a homogenizer by means of surfactants, and the resulted emulsions were characterized in terms of particle size, zeta potential, charge density, minimal inhibitory concentration (MIC), and adsorption capacity. After that the hydrophobicity of emulsion treated hand‐sheets was determined by measuring water contact angle (WCA). The morphology of the hand‐sheets treated by the emulsion was revealed using scanning electron microscope (SEM) and atom force microscope (AFM). Finally, the antimicrobial properties of the emulsion treated hand‐sheets were investigated by anti‐mold tests against Aspergillus niger and Chaetomium globosum. Results indicated that the PEW‐g‐PHGH emulsions exhibited good stability, high fiber adsorption capacity, and antimicrobial activity. The WCAs of the treated hand‐sheets reached 82°–140° with 80%∼99.9% growth inhibition against fungi. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42214.
Effect of electron beam irradiation on the properties of polylactic acid/montmorillonite nanocomposites for food packaging applications
Authors: Salvatore Marcella , Marra Antonella , Duraccio Donatella , Shayanfar Shima , Pillai Suresh D. , Cimmino Sossio , Silvestre Clara 
Published: April 2015

ABSTRACTThis study was aimed at (1) developing new films based on polylactic acid/montmorillonite (PLA/MMT) with improved properties for applications in the food packaging industry and (2) analyzing the effect of electron‐beam (eBeam) radiation on the structural, morphological, mechanical, and barrier properties of these nanomaterials. Nanocomposites based on PLA with 1, 3, and 5 wt % of MMT were prepared in a twin‐screw extruder and then filmed by a calender. The nanocomposites were exposed to eBeam doses; one set at 1 kGy dose and the other at 10 kGy dose. The effect of MMT addition and of eBeam radiation on the properties of PLA were assessed. For all composites, a homogeneous distribution and dispersion of MMT in the PLA matrix was obtained. All nanocomposites showed an increase of the mechanical and oxygen‐barrier properties compared to neat PLA. The eBeam irradiation caused an increase of the crystallinity, formation of crosslink, increase of the glass‐transition temperatures, and enhancement of the yield values in the stress–strain curves for all nanocomposites. This study demonstrated that PLA/MMT films are suitable materials for eBeam processing of prepacked food at the realistic doses that were employed in this study. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42219.
Effect of glass transition temperature and saturation temperature on the solid‐state microcellular foaming of cyclic olefin copolymer
Authors: Guo Huimin , Kumar Vipin 
Published: April 2015

ABSTRACTEffect of glass transition temperature and saturation temperature on the solid‐state microcellular foaming of cyclic olefin copolymer (COC)—including CO2 solubility, diffusivity, cell nucleation, and foam morphology—were investigated in this article. COCs of low Tg (78°C) and high Tg (158°C) were studied. Solubilities are 20–50% higher in high Tg COC than in the low Tg COC across the saturation temperature range. Diffusivities are about 15% higher on average in high Tg COC for temperatures up to 50°C. A much faster increase of diffusivity beyond 50°C is observed in low Tg COC due to it being in the rubbery state. Under similar gas concentration, high Tg COC starts foaming at a higher temperature. And the foam density decreases faster in low Tg COC with foaming temperature. Also, high Tg COC foams show about two orders of magnitude higher cell nucleation density than the low Tg COC foams. The effect of saturation temperature on microcellular foaming can be viewed as the effect of CO2 concentration. Nucleation density increases and cell size decreases exponentially with increasing CO2 concentration. Uniform ultramicrocellular structure with an average cell size of 380 nm was created in high‐Tg COC. A novel hierarchical structure composed of microcells (2.5 μm) and nanocells (cell size 80 nm) on the cell wall was discovered in the very low‐density high‐Tg COC foams. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42226.
Comparison of catalytic hydrolysis of bagasse cellulose under heterogeneous and homogeneous systems
Authors: Wang Yan , Yao Shun , Yang Chang , Zhang Feng , Xue Yang , Song Hang 
Published: April 2015

ABSTRACTThe conversion of cellulose into valuable chemicals has attracted a great deal of interest. In this study, heterogeneous and homogeneous systems in the conversion of bagasse cellulose into the total reducing sugars were investigated. In the heterogeneous system, the effects of several critical factors including types and concentrations of ionic liquid, temperature, and time were all investigated for cellulosic conversion. Parameters considered included temperature, dosage of catalyst, and water in the homogeneous system. It was found that the hydrolysis capacity for cellulose in homogeneous system was better than that in heterogeneous system. In addition, the structure and physicochemical properties of the treated cellulose were characterized by Fourier transform infrared spectroscopy, thermogravimetry, and scanning electron microscopy, and then compared with the native fibers. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42228.
Degradation of aviation sealing materials in rapeseed biodiesel
Authors: Dubovský Michal , Božek Marián , Olšovský Milan 
Published: April 2015

ABSTRACTNowadays, the airline industry and worldwide companies in the aerospace industry have been forced to find new ecological alternatives to traditional fuels to substitute as aviation fuels and kerosene. In aero turbo engines, rubber seals based on nitrile–butadiene rubber (NBR) with different contents of acrylonitrile are the most commonly used for the production of seals. This NBR is characterized by excellent physical and mechanical properties. In this article, we present the effects of critical operating conditions and the addition of the methyl ester of rapeseed oil to aviation fuel in relation to seals for aircraft engines. In this study, we evaluated changes in the physical and mechanical properties of rubber blends that were produced from NBR rubber. The exact composition and material properties were obtained from the producer. Static immersion tests in B10 (10% biodiesel in diesel), B50 (50% biodiesel in diesel), B75 (75% biodiesel in diesel), and B100 (100% biodiesel) were carried out at a higher temperature (100°C) for 500 h and at laboratory temperature (23 ± 2°C) for 3000 h. At the end of the immersion test, the degradation behavior was investigated by the measurement of the relative changes in the weight, hardness, tensile strength, and elongation. The change in the rubber surface morphology was studied by optimal microscopy and with a digital camera. The results show that the extent of rubber blend degradation was observed for samples that were exposed to a higher concentration of biodiesel and to a higher temperature. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42254.
A highly sensitive square wave voltammetry based biosensor for kinase activity measurements
Authors: Snir Elza , Amit Einav , Friedler Assaf , Yitzchaik Shlomo 
Published: April 2015

ABSTRACTAn electrochemical biosensor has been developed for ultrasensitive, label‐free determination of protein kinase activity. The sensor is composed of a unique peptide monolayer on a gold electrode. It identifies the order change in the monolayer upon phosphorylation, via square wave voltametry (SWV) measurements. Disorder caused by the introduction of the phosphate groups onto the middle of the peptide sequence results in pinhole formation and therefore an increase in the electrochemical signal. The measured sensitivity was 100 nM of kinase and the dynamic range was 100 nM up to 11 μM. Sensitivity was an order of magnitude higher, and the dynamic range wider by two orders of magnitude, as compared to our previously reported impedimetric method, in which the sensitivity was 1 μM, and the dynamic range was 1–20 μM. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 104: 515–520, 2015.
Engineered microstructure granules for tailored drug release rate
Authors: Hong Min‐Ho , Choi Heon‐Jin , Ko Yeong‐Mu , Lee Yong‐Keun 
Published: April 2015

ABSTRACTBiomaterials developed for controlled drug delivery have demonstrated excellent results in the present study. A biomaterial prepared using hydroxyapatite (HAp) was shown to have a hollow structure with the presence of interconnected pores to house drug carriers. The poly(lactic‐co‐glycolic acid) particles were used as drug carriers loaded with dexamethasone, a corticosteroid that is known to promote osteoinduction. The surface of the drug carriers was modified using polyethyleneimine, and then conjugated to the surface of HAp granules. The hollow HAp granules had drug carriers on both their inner and outer surfaces and showed a controlled drug release rate that was comparable to that of granules containing drug carriers on their outer surface alone. The pores were designed for insertion of drug carriers and preosteoblasts. Consequently, the biomaterials influenced cellular behavior by first promoting cell proliferation and then inducing early stage osteogenic differentiation. The effects of controlled release rate were evidenced for up to two weeks after cell seeding, resulting in an increase of osteogenic differentiation. In summary, drug carriers loaded onto hollow HAp granules were shown to be suitable for patients who require replacement of missing bone for repair of bone fractures that are extremely complex, pose a significant health risk to the patient, or fail to heal properly. Biotechnol. Bioeng. 2015;112: 1936–1947. © 2015 Wiley Periodicals, Inc.
A novel polymeric drug delivery system for localized and sustained release of tacrolimus (FK506)
Authors: Tajdaran Kasra , Shoichet Molly S. , Gordon Tessa , Borschel Gregory H. 
Published: April 2015

ABSTRACTDespite substantial improvement in microsurgical techniques for nerve repair, recovery after peripheral nerve injury is usually incomplete. FK506, an FDA approved immunosuppressant, improves functional recovery and reinnervation following peripheral nerve injury in animal models. However, systemically delivered FK506 causes undesirable global immunosuppression. We have, therefore, engineered a biodegradable local delivery system for FK506 using fibrin gel as a drug reservoir that could be placed at a site of nerve injury. FK506 was incorporated into fibrin gel in solubilized, particulated, and poly(lactic‐co‐glycolic) acid (PLGA) microspheres‐encapsulated forms. A tunable release of FK506 in the fibrin gel from days to weeks was observed with the rate of release being most rapid for the solubilized form and then the particulate form. The most prolonged period of release was seen with the PLGA microsphere‐encapsulated form. As analyzed by in vitro dorsal root ganglion (DRG) neurite extension assay, PLGA microsphere encapsulation of FK506 did not alter the drug's properties and the released FK506 maintained its bioactivity over the entire period of release. This study suggests that local delivery of FK506 with fibrin hydrogel could be used to enhance peripheral nerve regeneration. Biotechnol. Bioeng. 2015;112: 1948–1953. © 2015 Wiley Periodicals, Inc.
Online monitoring of fermentation processes via non‐invasive low‐field NMR
Authors: Kreyenschulte Dirk , Paciok Eva , Regestein Lars , Blümich Bernhard , Büchs Jochen 
Published: April 2015

ABSTRACTFor the development of biotechnological processes in academia as well as in industry new techniques are required which enable online monitoring for process characterization and control. Nuclear magnetic resonance (NMR) spectroscopy is a promising analytical tool, which has already found broad applications in offline process analysis. The use of online monitoring, however, is oftentimes constrained by high complexity of custom‐made NMR bioreactors and considerable costs for high‐field NMR instruments (>US$200,000). Therefore, low‐field 1H NMR was investigated in this study in a bypass system for real‐time observation of fermentation processes. The new technique was validated with two microbial systems. For the yeast Hansenula polymorpha glycerol consumption could accurately be assessed in spite of the presence of high amounts of complex constituents in the medium. During cultivation of the fungal strain Ustilago maydis, which is accompanied by the formation of several by‐products, the concentrations of glucose, itaconic acid, and the relative amount of glycolipids could be quantified. While low‐field spectra are characterized by reduced spectral resolution compared to high‐field NMR, the compact design combined with the high temporal resolution (15 s–8 min) of spectra acquisition allowed online monitoring of the respective processes. Both applications clearly demonstrate that the investigated technique is well suited for reaction monitoring in opaque media while at the same time it is highly robust and chemically specific. It can thus be concluded that low‐field NMR spectroscopy has a great potential for non‐invasive online monitoring of biotechnological processes at the research and practical industrial scales. Biotechnol. Bioeng. 2015;112: 1810–1821. © 2015 Wiley Periodicals, Inc.
Isolation and purification of monosialotetrahexosylgangliosides from pig brain by extraction and liquid chromatography
Authors: Bian Liujiao , Yang Jianting , Sun Yu 
Published: April 2015

AbstractMonosialotetrahexosylganglioside (GM1), one of glycosphingolipids containing sialic acid, plays particularly important role in fighting against paralysis, dementia and other diseases caused by brain and nerve damage. In this work, a simple and highly efficient method with high yield was developed for isolation and purification of GM1 from pig brain. The method consisted of an extraction by chloroform–methanol–water and a two‐step chromatographic separation by DEAE–Sepharose Fast Flow anion‐exchange medium and Sephacryl S‐100 HR size‐exclusion medium. The purified GM1 was proved to be homogeneous and had a purity of >98.0% by high‐performance anion‐exchange and size‐exclusion chromatography. The molecular weight was 30.0 kDa by high‐performance size‐exclusion chromatography and 1546.9 Da by electrospray ionization mass spectrometry. The chromogenic reaction by resorcinol–hydrochloric acid solution indicated that the purified GM1 showed a specific chromogenic reaction of sialic acid. Through this isolation and purification program, ~1.0 mg of pure GM1 could be captured from 500 g wet pig brain tissue and the yield of GM1 was around 0.022%, which was higher than the yields by other methods. The method may provide an alternative for isolation and purification of GM1 in other biological tissues. Copyright © 2015 John Wiley & Sons, Ltd.
Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry
Authors: Joshi Amit D. , Kim Andre , Lewinger Juan Pablo , Ulrich Cornelia M. , Potter John D. , Cotterchio Michelle , Le Marchand Loic , Stern Mariana C. 
Published: April 2015

AbstractDiets high in red meat and processed meats are established colorectal cancer (CRC) risk factors. However, it is still not well understood what explains this association. We conducted comprehensive analyses of CRC risk and red meat and poultry intakes, taking into account cooking methods, level of doneness, estimated intakes of heterocyclic amines (HCAs) that accumulate during meat cooking, tumor location, and tumor mismatch repair proficiency (MMR) status. We analyzed food frequency and portion size data including a meat cooking module for 3364 CRC cases, 1806 unaffected siblings, 136 unaffected spouses, and 1620 unaffected population‐based controls, recruited into the CRC Family Registry. Odds ratios (OR) and 95% confidence intervals (CI) for nutrient density variables were estimated using generalized estimating equations. We found no evidence of an association between total nonprocessed red meat or total processed meat and CRC risk. Our main finding was a positive association with CRC for pan‐fried beefsteak (Ptrend < 0.001), which was stronger among MMR deficient cases (heterogeneity P = 0.059). Other worth noting associations, of borderline statistical significance after multiple testing correction, were a positive association between diets high in oven‐broiled short ribs or spareribs and CRC risk (Ptrend = 0.002), which was also stronger among MMR‐deficient cases, and an inverse association with grilled hamburgers (Ptrend = 0.002). Our results support the role of specific meat types and cooking practices as possible sources of human carcinogens relevant for CRC risk.
Peritoneal pregnancy with massive hemoperitoneum in early gestation: two case reports
Authors: Miyauchi Azumi , Yamada Mitsutoshi , Furuya Masataka , Matsumura Satoko , Murayama Shinji , Yoshimura Yasunori , Tanaka Mamoru 
Published: April 2015

Key Clinical MessagePeritoneal pregnancy may cause severe abdominal bleeding without genital bleeding as early as the fifth week of gestation. Awareness that pregnancy can exist in unusual locations is imperative.
Surface Chirality of Gly‐Pro Dipeptide Adsorbed on a Cu(110) Surface
Authors: Cruguel Hervé , Méthivier Christophe , Pradier Claire‐Marie , Humblot Vincent 
Published: April 2015

AbstractThe adsorption of chiral Gly‐Pro dipeptide on Cu(110) has been characterized by combining in situ polarization modulation infrared reflection absorption spectroscopy (PM‐RAIRS) and X‐ray photoelectron spectroscopy (XPS). The chemical state of the dipeptide, and its anchoring points and adsorption geometry, were determined at various coverage values. Gly‐Pro molecules are present on Cu(110) in their anionic form (NH2/COO−) and adsorb under a 3‐point binding via both oxygen atoms of the carboxylate group and via the nitrogen atom of the amine group. Low‐energy electron diffraction (LEED) and scanning tunneling microscopy (STM) have shown the presence of an extended 2D chiral array, sustained via intermolecular H‐bonds interactions. Furthermore, due to the particular shape of the molecule, only one homochiral domain is formed, creating thus a truly chiral surface. Chirality 27:411–416, 2015. © 2015 Wiley Periodicals, Inc.