bluuebunny/crossref_metadata_2025_split huggingface dataset:
The production of lipopeptides by Bacillus subtilis with desizing wastewater and application in soaping process
Authors: Li Ming‐Jian , Yang Qun , Shao Fen‐Juan , Lu Da‐Nian 
Published: March 2011

AbstractIn this article, a low‐cost medium for the production of lipopeptides by the Bacillus subtilis HSO121 was formulated with desizing wastewater as carbon source, which contains starch and its degradation products, and the lipopeptides were biosynthesized. As the result, the yield of crude lipopeptides was 1.03 g/L, and the critical micelle concentration was ∼ 50 mg/L. The chemical oxygen demand of the desizing wastewater after cultivation reduced to half compared with before cultivation. Separation of crude lipopeptides and its application as soaping agents in soaping process were investigated. The optimal soaping process was obtained at pH = 9 and 75°C with 0.05 g/L lipopeptides. Compared with traditional soaping process, lipopeptides soaping showed higher efficiency and higher colorfastness, and it is more energy efficient and more environmentally friendly process. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A new composition–processing–property relationship for studying the tensile modulus‐phase plastic blends
Authors: Jodeh Shehdeh 
Published: March 2011

AbstractBased on thermodynamic principles, a composition–processing–property relationship for predicting the modulus properties of multiphase plastic blends has been developed. This relationship describes the relative modulus of the blend in terms of the volume fraction and the index for the degree of mixing of an inclusion‐polymer in the matrix‐polymer. The relative modulus is defined as the ratio between the modulus of the blend and that of the matrix polymer. These blends include a nylon 6,6/polymethyl methacrylate(PMMA) system mixed using an injection molding process arid a nylon 6/ethylene‐vinyl acetate copolymer system mixed using a corotational extrusion process. Based on the values determined for the mixing index of the nylon 6,6/PMMA blends, a relationship between the mixing index and the fill time used in the injection molding has been developed. The results also imply that the degree of mixing of the blend mixed using a correlation extrusion process is better than that of the blend processed using an injection molding process. Using the above results, we now can scientifically develop new plastic blends and design optimum processing conditions for various automotive applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
In vitro controlled release of polymeric drug‐saccharide conjugates with ketoprofen, ibuprofen, and naproxen pendants
Authors: Wu Chengyao , Xie Jiangang , Branford‐White Christopher , Quan Jing , Zhu Limin 
Published: March 2011

AbstractPolymerizable monomers of glucose and three types of nonsteroidal anti‐inflammatory drugs were prepared. Free radical polymerization of the resulting monomers was carried out in DMF. The polymers with drug pendent were characterized using FTIR, NMR, and GPC spectroscopy. Following hydrolysis of polymeric drug‐saccharide conjugates at 37°C, the cumulative released of naproxen, ibuprofen, and ketoprofen were 70, 55, and 30% after 10 days, respectively. Half‐lives (t1/2) of the copolymers were calculated through the first 12 h and these were found to be 4.2, 5.3, and 7.8 h, suggesting a slow and sustained drug release mechanism. The drug release profiles were also carried out at different pH, temperature, and ionic strength and solution varieties. It was concluded that different release profiles occurred and were dependent on temperature and pH. It was apparent that the polymeric drug‐saccharide conjugate had the potential to be developed as a system that enhances drug delivery. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The effect of synthesis methods on the mechanical properties of self‐crosslinkable poly(n‐butyl methacrylate‐co‐N‐methylolacrylamide) films
Authors: Aguilar J. , Mendizábal E. , Nuño‐Donlucas S. M. , Arellano M. , Puig J. E. , Rabelero M. 
Published: March 2011

AbstractThe effects of particle size and parent polymer characteristics on the mechanical properties, gel fraction, and swelling index of self‐crosslinkable poly(n‐butyl methacrylate‐co‐N‐methylolacrylamide) films made by two‐stage emulsion or microemulsion polymerization in the presence of variable amounts of the chain transfer agent, n‐butyl mercaptan, are reported here. In films prepared with latexes made by microemulsion polymerization, the crosslinking degree increased greatly on curing; by contrast, in those made by emulsion polymerization, the crosslinking degree practically did not increase after curing. Stress–strain tests of uncured and cured films indicate that microemulsion‐made films are tougher than the emulsion‐made films. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of acrylic acid and AMPS cointercalated layered double hydroxide and its application for superabsorbent
Authors: Shi Shuxian , Guo Fang , Xia Yuzheng , Su Zhiqiang , Chen Xiaonong , Wei Min 
Published: March 2011

AbstractThis article reports the cointercalation of acrylic acid (AA) and 2‐acrylamido‐2‐methylpropane sulfonic acid (AMPS) in the interlayer region of Mg2Al layered double hydroxide (LDH) and the application of this inorganic–organic composite material in the field of water superabsorbent. The monomers of AA and AMPS were cointercalated into galleries of Mg2Al−LDH (denoted as AA−AMPS/LDH) with various molar ratios by ion‐exchange method, which was confirmed by powder X‐ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR), and elemental analysis. The polymer‐based superabsorbent was prepared through in situ free‐radical aqueous copolymerization of AA and AMPS, with AA−AMPS/LDH as additive, N,N′‐methylenebisacrylamide (NMBA) as crosslinker and potassium persulfate (KPS) as initiator. The composition of this poly(AA‐co‐AMPS)/LDH was demonstrated as a good water superabsorbent. The LDH content, water absorbency, thermal stability, and swelling rate of this superabsorbent were also investigated in detail. Results showed that the incorporation of a 5 wt % AA−AMPS/LDH into polymer matrix increased its water absorbency significantly by 27.7% (in water) and by 51.5% (in 0.9 wt % NaCl solution). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation of gold–poly(vinyl pyrrolidone) core–shell nanocomposites and their humidity‐sensing properties
Authors: Chen Xue Jiao , Zhang Jian , Ma Dian Fei , Hui Shi Chao , Liu Yan Li , Yao Wei 
Published: March 2011

AbstractThe humidity‐sensing properties of gold (Au)–poly(vinyl pyrrolidone) (PVP) core–shell nanocomposites were investigated. Au–PVP nanocomposites were synthesized and then incorporated into a capacitive‐type humidity sensor as a dielectric. Because of the adsorption/desorption of water molecules, the variation of capacitance under different humidity levels was examined by the capacitance–frequency conversion circuit and recorded by a LabVIEW system in terms of the frequency shift. As the relative humidity (RH) increased from 11.3 to 93%, the output frequency decreased monotonically, with a sen sitivity of about −136 Hz/% RH. Also, the good reproducibility and stability, fast response, and low hysteresis made the pellet a suitable candidate for humidity sensing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Preparation and properties of crosslinked multiblock sulfonated poly(arylene ether sulfone) membranes for fuel cell applications
Authors: Zhang Xuan , Hu Zhaoxia , Zhang Sha , Chen Shouwen , Chen Shanshan , Liu Jianmei , Wang Lianjun 
Published: March 2011

AbstractNovel multiblock poly(arylene ether sulfone)s were prepared by a two‐pot method from a phenoxide‐end‐capped fully disulfonated poly(arylene ether sulfone) oligomer and a fluoride‐end‐capped nonsulfonated poly(arylene ether sulfone) oligomer with block length of 10 as the hydrophilic and hydrophobic moieties, respectively, and were subsequently used as starting materials to be treated with phosphorous pentoxide (P2O5) to get crosslinked membranes. The crosslinking reaction occurred between the sulfonic acid groups and activated ortho‐hydrogen atoms to the ether linkage of the hydrophobic units in the presence of P2O5 during solution casting. The crosslinking ratio was simply controlled by the amount of P2O5, and the fundamental properties of the resulting crosslinked multiblock membranes were investigated in detail. The water uptake and solution uptake in methanol solutions decreased with increasing crosslinking ratio, but a comparable high proton conductivity was maintained in the uncrosslinked membranes. They exhibited isotropic swelling behavior and largely enhanced dimensional stability in water and methanol solutions, whereas the uncrosslinked one showed anisotropic swelling behavior. The oxidative stability of the crosslinked membranes was significantly enhanced by the formation of sulfonyl linkages. The high proton conductivities at 120°C and 50% relative humidity suggested promising applications in elevated temperatures. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Mechanism of degradation of poly(p‐phenylene benzobisoxazole) under hydrolytic conditions
Authors: Fu Qian , Zhang Huiru , Song Bo , Liu Xiaoyun , Zhuang Qixin , Han Zhewen 
Published: March 2011

AbstractPoly(p‐phenylene benzobisoxazole) (PBO) fiber has received great interest because of its excellent mechanical properties and good thermal stability. The objective of this study was to expose degradation mechanism of PBO under neutral and acidic conditions by molecular mass and Fourier transform infrared (FTIR) spectroscopy. Results were not consistent with the classic degradation mechanism, which indicates that degradation should occur through the ring opening and chain scission of the benzoxazole ring. The FTIR absorption spectra of PBO suggested that the o‐hydroxy amide linkage (the open ring structure) was present in the PBO molecule chain to some extent because of the incomplete polymerization. Further investigation showed that hydrolysis might occur in the open ring section during hydrolytic degradation. Based on the experimental data, a new degradation mechanism was proposed. It suggests that, in the early and middle stages, hydrolysis occurred primarily in the o‐hydroxy amide linkage of the open ring. The concentration of the o‐hydroxy amide structure determined the speed of degradation of PBO. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Crack initiation and propagation in circular rubber bearings subjected to cyclic compression
Authors: Chou Hsoung‐Wei , Huang Jong‐Shin 
Published: March 2011

AbstractThe fatigue failure mechanism of rubber bearings under cyclic compression is important in evaluating their fatigue lives and thus is analyzed theoretically and numerically here. At first, the stress distributions in a bonded rubber cylinder derived from three different existing models were utilized to calculate the cracking energy densities within it. Next, the location of fatigue crack initiation and the direction of subsequent crack propagation in circular rubber bearings were consecutively determined. Furthermore, finite element numerical results were compared to those obtained theoretically from the three models to check their validity in predicting the fatigue crack initiation and propagation in circular rubber bearings. Based on the quasi‐statically theoretical and numerical results, it is found that the fatigue cracks initiate first at the outermost boundary between rubber and steel plates and propagate later inwards to the center of circular rubber bearings. The corresponding fatigue failure mechanism obtained theoretically and numerically is consistent with experimental findings reported previously. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Using embryology screencasts: A useful addition to the student learning experience?
Authors: Evans Darrell J.R. 
Published: March 2011

AbstractAlthough podcasting has been a well used resource format in the last few years as a way of improving the student learning experience, the inclusion of enhanced audiovisual formats such as screencasts has been less used, despite the advantage that they work well for both visual and auditory learners. This study examines the use of and student reaction to a set of screencasts introduced to accompany embryology lectures within a second year module at Brighton and Sussex Medical School. Five mini‐lecture screencasts and one review quiz screencast were produced as digital recordings of computer screen output with audio narration and released to students via the managed learning environment (MLE). Analysis of server log information from the MLE showed that the screencasts were accessed by many of the students in the cohort, although the exact numbers were variable depending on the screencast. Students accessed screencasts at different times of the day and over the whole of the access period, although maximum downloads were predictably recorded leading up to the written examination. Quantitative and qualitative feedback demonstrated that most students viewed the screencasts favorably in terms of usefulness to their learning, and end‐of‐module written examination scores suggest that the screencasts may have had a positive effect on student outcome when compared with previous student attainment. Overall, the development of a series of embryology screencasts to accompany embryology lecture sessions appears to be a useful addition to learning for most students and not simply an innovation that checks the box of “technology engagement.” Anat Sci Educ 4: 57–63, 2011. © 2011 American Association of Anatomists.
Linear and Hyperbranched Electron‐Acceptor Supramolecular Oligomers
Authors: Santos José , Pérez Emilio M. , M. Illescas Beatriz , Martín Nazario 
Published: March 2011

AbstractThe nanometric organization of p‐type and n‐type materials is expected to facilitate charge mobility in OSCs, thereby preventing recombination and enhancing efficiency. Herein, the synthesis and self‐assembly of monomers comprising one or two units of a TCAQ tweezer covalently connected to a fullerene derivative is reported. Such molecules self‐assemble in solution (NMR) and on surfaces (AFM) to form linear and hyperbranched supramolecular oligomers, respectively. The self‐assembly process was also found to have very little influence on the electronic properties of the electroactive units of the monomers (CV and UV/Vis), as was expected from their matching character. These polymers constitute two of the first examples of n‐type supramolecular polymers reported to date.
Paper 6: EUROCAT member registries: Organization and activities
Authors: Greenlees Ruth , Neville Amanda , Addor Marie–Claude , Amar Emmanuelle , Arriola Larraitz , Bakker Marian , Barisic Ingeborg , Boyd Patricia A. , Calzolari Elisa , Doray Berenice , Draper Elizabeth , Emil Vollset Stein , Garne Ester , Gatt Miriam , Haeusler Martin , Kallen Karin , Khoshnood Babak , Latos–Bielenska Anna , Martinez–Frias Maria–Luisa , Materna–Kiryluk Anna , Matias Dias Carlos , McDonnell Bob , Mullaney Carmel , Nelen Vera , O'Mahony Mary , Pierini Anna , Queisser–Luft Annette , Randrianaivo–Ranjatoélina Hanitra , Rankin Judith , Rissmann Anke , Ritvanen Annukka , Salvador Joaquin , Sipek Antonin , Tucker David , Verellen–Dumoulin Christine , Wellesley Diana , Wertelecki Wladimir 
Published: March 2011

AbstractBACKGROUNDEUROCAT is a network of population‐based congenital anomaly registries providing standardized epidemiologic information on congenital anomalies in Europe. There are three types of EUROCAT membership: full, associate, or affiliate. Full member registries send individual records of all congenital anomalies covered by their region. Associate members transmit aggregate case counts for each EUROCAT anomaly subgroup by year and by type of birth. This article describes the organization and activities of each of the current 29 full member and 6 associate member registries of EUROCAT.METHODSEach registry description provides information on the history and funding of the registry, population coverage including any changes in coverage over time, sources for ascertaining cases of congenital anomalies, and upper age limit for registering cases of congenital anomalies. It also details the legal requirements relating to termination of pregnancy for fetal anomalies, the definition of stillbirths and fetal deaths, and the prenatal screening policy within the registry. Information on availability of exposure information and denominators is provided. The registry description describes how each registry conforms to the laws and guidelines regarding ethics, consent, and confidentiality issues within their own jurisdiction. Finally, information on electronic and web‐based data capture, recent registry activities, and publications relating to congenital anomalies, along with the contact details of the registry leader, are provided.CONCLUSIONSThe registry description gives a detailed account of the organizational and operational aspects of each registry and is an invaluable resource that aids interpretation and evaluation of registry prevalence data. Birth Defects Research (Part A) , 2011.© 2011 Wiley‐Liss, Inc.
A Site‐Saturated Mutagenesis Study of Pentaerythritol Tetranitrate Reductase Reveals that Residues 181 and 184 Influence Ligand Binding, Stereochemistry and Reactivity
Authors: Toogood Helen S. , Fryszkowska Anna , Hulley Martyn , Sakuma Michiyo , Mansell David , Stephens Gill M. , Gardiner John M. , Scrutton Nigel S. 
Published: March 2011

AbstractWe have conducted a site‐specific saturation mutagenesis study of H181 and H184 of flavoprotein pentaerythritol tetranitrate reductase (PETN reductase) to probe the role of these residues in substrate binding and catalysis with a variety of α,β‐unsaturated alkenes. Single mutations at these residues were sufficient to dramatically increase the enantiopurity of products formed by reduction of 2‐phenyl‐1‐nitropropene. In addition, many mutants exhibited a switch in reactivity to predominantly catalyse nitro reduction, as opposed to CC reduction. These mutants showed an enhancement in a minor side reaction and formed 2‐phenylpropanal oxime from 2‐phenyl‐1‐nitropropene. The multiple binding conformations of hydroxy substituted nitro‐olefins in PETN reductase were examined by using both structural and catalytic techniques. These compounds were found to bind in both active and inhibitory complexes; this highlights the plasticity of the active site and the ability of the H181/H184 couple to coordinate with multiple functional groups. These properties demonstrate the potential to use PETN reductase as a scaffold in the development of industrially useful biocatalysts.
Progress in Carbonylative‐Heck Reactions of Aryl Bromides: Catalysis and DFT Studies
Authors: Wu Xiao‐Feng , Jiao Haijun , Neumann Helfried , Beller Matthias 
Published: March 2011

AbstractImproved palladium‐catalyzed carbonylative Heck coupling reactions of aryl bromides with styrenes are described. Applying a [{(cinnamyl)PdCl}2]/PPh3 catalyst system, >20 chalcones with various functional groups were synthesized in 45–90 % yield. The reaction mechanism of this coupling reaction was studied by detailed DFT computations, which show that the carbonylation step is reversible.
Micronization of Fluticasone Propionate using Supercritical Antisolvent (SAS) Process
Authors: Su C.‐S. , Lo W.‐S. , Lien L.‐H. 
Published: March 2011

AbstractThe micronization of an asthma active pharmaceutical ingredient, fluticasone propionate, using the supercritical antisolvent (SAS) process was investigated in this study. The most commonly used supercritical carbon dioxide was employed as the antisolvent. The effects of five process parameters, including operating temperature, operating pressure, solution flow rate, solution concentration, and nozzle diameter, were compared and discussed. The physical properties of micronized fluticasone propionate were examined by the particle size analyzer, the scanning electron microscope and X‐ray diffractometer. The cross interaction effect of operating temperature and pressure was observed in the SAS treatment of fluticasone propionate and verified by the method of calculated mixture critical point (MCP), using the predictive Soave‐Redlich‐Kwong equation of state. Operation slightly above the MCP was suggested for successful micronization of fluticasone propionate.
Electrospray Crystallization for High‐Quality Submicron‐Sized Crystals
Authors: Radacsi N. , Stankiewicz A. I. , Creyghton Y. L. M. , van der Heijden A. E. D. M. , ter Horst J. H. 
Published: March 2011

AbstractNano‐ and submicron‐sized crystals are too small to contain inclusions and are, therefore, expected to have a higher internal quality compared to conventionally sized particles (several tens to hundreds of microns). Using electrospray crystallization, nano‐ and submicron‐sized crystals can be easily produced. With the aid of electrospray crystallization, a mist of ultrafine solution droplets is generated and subsequent solvent evaporation leads to crystallization of submicron‐sized crystals. Using cyclotrimethylene trinitramine (RDX) solutions in acetone, the conditions for a stable and continuous jet were established. At relatively small nozzle diameters and relatively low potential differences, hollow spheres of RDX crystals were observed. At a higher nozzle diameter and potential difference and in the region of a continuous jet, RDX crystals with an average size of around 400 nm could be produced. In order to test the quality of the submicron‐sized energetic material, impact and friction sensitivity tests were carried out. The test results indicate that the submicron‐sized product had reduced friction sensitivity, indicating a higher internal quality of the crystalline product.
Solvent and Substituent Effects on the Photochemistry of Norbornadiene‐Diarylacetylene Pauson–Khand Adducts
Authors: Ji Yining , Verdaguer Xavier , Riera Antoni 
Published: March 2011

AbstractThe photochemistry of Pauson–Khand cycloadducts of norbornadiene with a series of bis‐aryl alkynes has been studied. Two types of photochemical transformation take place: photorearrangement to tricyclic ketones or photochemical 6π electrocyclization. High selectivity levels have been attained for each pathway, controlled by the polarity of the solvent, irradiation wavelength, and presence (or absence) of oxygen.