bluuebunny/crossref_metadata_2025_split huggingface dataset:
Examining the use of TiO2 to enhance the NH3 sensitivity of polypyrrole films
Authors: Wu Yan , Xing Shuangxi , Fu Jiacai 
Published: July 2010

AbstractPolypyrrole/Titanium dioxide (PPy/TiO2) composite thin films were prepared by polymerizing the monomer pyrrole in aqueous solution containing a certain amount of TiO2 particles at room temperature, and their response to ammonia (NH3) gas was examined systematically. Compared with the pristine PPy film, which reached the saturation at the concentration of NH3 beyond 200 ppm, the composite films showed more stable response and higher sensitivity. Furthermore, the PPy/TiO2 composite thin films exhibited a low detection limit of 2 ppm. The film thickness, which had a strong influence on the film sensitivity to NH3, could be controlled by varying the polymerization time. The sensitivity to NH3 gas of the samples with different content of TiO2 and different molar ratio of PPy/TiO2/oxidant was studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, characterization, and pyrolysis of ferrocenyl unit containing organosilicon polymers
Authors: Hu Xiaowen , Li Yongming , Xu Caihong 
Published: July 2010

AbstractNew polyferrocenylsiloxanes (PFSXs) and polyferrocenylsilazanes (PFSZs) with linear or linear‐cyclic structure were prepared. The ceramic yields of the polymers were estimated by thermogravimetric analysis (TGA) and bulk pyrolysis, which closely depend on molecular structures. Compared with that of their linear counterparts having comparable molecular weights, the ceramic yields of linear‐cyclic PFSX and PFSZ were much higher. The pyrolysis process was investigated by lysis character is (TGA) highly depend on their molecular weights and structures, infrared spectra, and pyrolysis‐gas chromatography‐mass spectra (Py‐GC‐MS) analysis. The results indicated rather amount of ferrocene‐based small molecules were formed during the pyrolysis of linear polymers in the range of 25–300°C, whereas the existence of crosslinking or branched structure in the linear‐cyclic polymers prohibited this transformation, and therefore, dramatically improved the ceramic yields. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Thermogelling of highly branched poly(N‐isopropylacrylamide)
Authors: Tao Wei , Yan Lifeng 
Published: July 2010

AbstractHighly branched poly(N‐isopropylacrylamide) (PNIPAM) has been synthesized by a reversible addition‐fragmentation chain transfer (RAFT) copolymerization of NIPAM and a vinyl contained trithiocarbonate RAFT agent. 1H‐NMR measurements revealed that the degrees of branch (DB) are in the range of 0.032–0.105. Laser light scattering (LLS) measurements gave the hydrodynamic radii (Rh) of the polymers to be 3.6–5.7 nm with molecular weight in the range of 1.3 × 104 g/mol–2.3 × 10−4 g/mol. Highly branched PNIPAM with terminal thiol groups were obtained by aminolysis the polymers, and the product can be oxidized by air to form disulfide bonds (SS) among chains and resulting in the formation of nanoparticle in aqueous solution. Interestingly, the nanoparticle in size of Rh ˜ 80 nm showed a thermogelling behavior to form bulk hydrogel when the temperature was increased up to 25°C due to the thermo‐induced association of the PNIPAM chains among the nanoparticles. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Effect of poly(epichlorohydrin) on the thermal and mechanical properties of poly(vinyl chloride)
Authors: Ren Yiming , Wu Guangfeng , Zhao Xiaoxing , Liu Xiaoli , Liu Fengqi 
Published: July 2010

AbstractFive kinds of polyepichlorohydrin (PECH) of different molecular weights were synthesized and characterized by gel permeation chromatography (GPC). Mechanical blending was used to mix PECH and poly(vinyl chloride) (PVC) together. The blends of different PVC/PECH ratios were characterized by thermogravimetric analysis (TGA), tensile tests, differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). TGA results show the thermal stability of PVC/PECH blends is desirable. Tensile tests indicate elongation at break is raised by increasing both the amount and the molecular weight of PECH. DSC is used to determine the glass transition temperature of PECH, and a quite low Tg is obtained. DMA results indicate that PECH has a perfect compatibility with PVC, when PECH concentration is below 20 wt %. There is only one peak in each tan δ curve, and the corresponding Tg decreases as PECH amount increases. However, above 20 wt %, phase separation takes place. The molecular weight of PECH also has a great influence on the glass transition temperature of the blends. This study shows that PECH is an excellent plasticizer for PVC, and one can tailor the glass transition temperature and tensile properties by changing the amount and the molecular weight of PECH. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis of perfluorohexyl‐terminated poly(ethylene oxide) using maghnite‐h as clay catalyst
Authors: Hachemaoui Aïcha , Yahiaoui Ahmed , Belbachir Mohammed 
Published: July 2010

AbstractActivated monomer cationic ring‐opening polymerization of ethylene oxide initiated with 1H,1H,2H, 2H‐perfluorooctan‐1‐ol, using acid exchanged montmorillonite clay called Maghnite‐H+ (Mag‐H+) as an effective catalyst, was carried out to obtain the corresponding homopolymers with narrow polydispersity ratios. The molecular weights of the obtained polymers could be controlled with the feed ratio of the monomer and initiator. The effect of amount of catalyst and time on the polymerization yield and viscosity of the polymers were studied. The structure was confirmed by 1H‐NMR and MALDI‐TOF‐MS. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Synthesis, characterization, and biodegradation of maleic anhydride, ethylene glycol‐copolymerization modified poly(D,L‐lactide acid) and their crosslinked products
Authors: Huang Meina , Wang Yuanliang , Luo Yanfeng 
Published: July 2010

AbstractNovel maleic anhydride (MAH), ethylene glycol oligomer‐modified poly(D,L‐lactide acid) (PEMLA), and crosslinked‐PEMLA were synthesized via a series of chemical bulk modification. Briefly, MAH copolymerized with ethylene oligomer [EGO (including EG, PEG200, PEG400)] to give the PEMA; thereafter, D,L‐lactide (DLLA) and prepolymers (PEMA) copolymerized to produce the PEMLA; at last, the crosslinked‐PEMLA was synthesized by free radical reaction of the PEMLA. The characterization of PEMLA and crosslinked‐PEMLA showed that the introduction of hydrophilic group O and CHCH increased the flexibility and hydrophilicity of PDLLA. Moreover, the degradation of PEMLA and crosslinked‐PEMLA were determined by molar weight changes and weight loss rate, and a special method, analysis of degradation positions via 1H‐NMR, which indicated that the PEMLA and crosslinked‐PEMLA have nice degradation, and the change of content of MAH, EGO can regulate the degradation rate of PDLLA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Preparation of microporous PVDF membrane via tips method using binary diluent of DPK and PG
Authors: Tang Yuanhui , Lin Yakai , Ma Wenzhong , Tian Ye , Yang Jian , Wang Xiaolin 
Published: July 2010

AbstractMicroporous polyvinylidene fluoride (PVDF) membrane was prepared via thermally induced phase separation (TIPS) method using a binary diluent of diphenyl ketone (DPK) and 1,2‐propylene glycol (PG). The phase diagram for the PVDF/binary diluent of DPK and PG system was measured in the range of the PG/DPK mass ratio changing from 0 to 2/3. Then the effects of the PG/DPK mass ratio and the PVDF concentration on membrane cross‐section structures and tensile strength were also investigated. The results showed that the addition of PG brought about a shift of the cloud point curve to a higher temperature and the extension of the liquid–liquid phase separation region to a higher polymer concentration. Therefore a bicontinuous cross‐section structure was obtained when the PG/DPK mass ratio was 3/7 and the polymer concentration was 30 wt %. As an increase of the PG/DPK mass ratio, the tensile strength increased gradually at a fixed PVDF concentration. Moreover, for the same PG/DPK mass ratio, the cross‐section microstructure changed from a bicontinuous or a cellular structure to a spherulitic structure, and the tensile strength increased drastically as the polymer concentration increased from 20 to 50 wt %. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Use of thermoplastic polyurethane elastomers in the preparation of fabric/activated carbon composites
Authors: Esclapez‐Vicente M.D. , Sánchez‐Adsuar María S. , Lillo‐Ródenas María A. , Linares‐Solano Angel 
Published: July 2010

AbstractA new application of thermoplastic polyurethane elastomers (TPUs), as composite binder in the preparation of fabric/activated carbon composites, is investigated. Different amounts of TPU in the impregnating solutions, different fabrics, and different activated carbons (ACs) were used to prepare the fabric/carbon composite samples. The adsorption properties of the resulting samples were tested, and the results obtained show the suitability of the composite preparation method proposed in this article. Moreover, the adsorption properties of the composite samples prepared are independent of the fabric used and dependent of the AC properties and the TPU amount used in the preparation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Structure and optical investigation of the effect of electron beam‐irradiation in poly‐allyl‐diglycol‐carbonate
Authors: Nouh S. A. , Abutalib M. M. 
Published: July 2010

AbstractThe effect of electron beam irradiation on the structural and optical properties of Poly‐Allyl‐Diglycol‐Carbonate CR‐39 solid state nuclear track detector was investigated. Samples from CR‐39 detector were irradiated with electron beam with doses at levels between 10 and 140 kGy. The structural and optical modifications in the electron beam irradiated CR‐39 samples have been studied as a function of dose using different characterization techniques such as FTIR spectroscopy, Vickers hardness, refractive index and color difference measurements. The electron beam irradiation in the dose range 25–140 kGy led to a more compact structure of CR‐39 polymer, which resulted in an improvement in its hardness with an increase in the refractive index. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Surface structure build‐up and three‐dimensional topography of polyurethane powder coatings
Authors: Pilch‐Pitera Barbara , Stagraczyñski Ryszard 
Published: July 2010

AbstractNon‐ and polysilsesquioxane‐containing polyurethane‐based powder coating systems, crosslinked with allophanate bonds containing polyisocyanates were examined. The surface structure built‐up of the powder coatings were investigated at different temperatures with a polarized optical microscopy (POM) using reflected light. The three‐dimensional surface topography and the values of surface roughness were determined. The surface structure was correlated with the chemical structure of the coatings and macroscopic surface behavior: surface free energy and gloss. These experimental results lead to a better understanding of the development of surface topography and morphology and provide valuable information for the development of new polyurethane powder coating systems. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Coextruded polyethylene and wood‐flour composite: Effect of shell thickness, wood loading, and core quality
Authors: Yao Fei , Wu Qinglin 
Published: July 2010

AbstractCoextruded recycled polyethylene and wood‐flour composites with core–shell structure were manufactured using a pilot‐scale coextrusion line. The influence of wood loadings and thickness of the shell layer and core quality on mechanical and water absorption properties of the composites were investigated. Core–shell structured profile can significantly improve flexural and impact strengths of composites especially when a relatively weak core was used. However, the coextruded profile with unreinforced shell may have a reduced modulus when a strong core was used. The shell layer also protected coextruded composites from long‐term moisture uptaking, leading to improved dimensional stability compared with the corresponding un‐coextruded controls. When the shell thickness was fixed, less wood loading in the shell layer did not cause obvious flexural modulus and dimension change but improved impact strength and water resistance of the coextruded composites. When wood loading in the shell layer was fixed, increased shell thickness improved impact strength but affected modulus negatively. Thickened shell layer helped reduce water uptaking but did not change dimensional stability of coextruded composites remarkably. Overall enhancement of composite strength was more pronounced for the weaker core system. Thus, the coextrusion technology can be used to achieve acceptable composite properties even with a relatively weak core system—offering an approach to use recycled, low quality plastic‐fiber blends in the core layer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010
Juvenile animal studies for the development of paediatric medicines: a description and conclusions from a European medicines agency workshop on juvenile animal testing for nonclinical assessors
Authors: Silva‐Lima Beatriz , Due Theilade‐Thomsen Mette , Carleer Jacqueline , Vidal Jean‐Marc , Tomasi Paolo , Saint‐Raymond Agnes 
Published: July 2010

AbstractA workshop organised by the European Medicines Agency involved assessors and experts present in a Nonclinical Working Group evaluating juvenile animal studies for Paediatric Investigation Plans in collaboration with the Paediatric Committee and the Safety Working Party of the Committee for Human Medicinal Products. The objective of the workshop was to analyse which juvenile animal studies proposals were received and agreed by the Paediatric Committee, to check consistency and how to apply the existing European guideline on juvenile animal studies. A comparison of main organ system development in man vs. animal species was presented to guide the review and to support species selection and protocol design. An analysis of juvenile animal studies included in finalised PIP's was also presented. Out of 109 paediatric investigation plans finalised between November 2008 and March 2009, 43 included one or more juvenile animal studies. In most cases the preferred species was the rat; one species only was requested to be studied (20/22), but in a minority two species were required (2/22). When deciding on the characteristics of the juvenile animal studies, such as age of animals at study start, the age of the children targeted by the medicine was considered. It is expected that the increasing experience gained by Applicants and Regulators will allow further refining the criteria for these juvenile animal studies. Further research on this topic is highly encouraged in the European Regulatory framework. Birth Defects Res (Part B) 89:467–473, 2010. © 2010 Wiley‐Liss, Inc.
Building the blueprint of life
Authors: Henry Christopher , Overbeek Ross , Stevens Rick L. 
Published: July 2010

AbstractWith recent breakthroughs in experimental microbiology making it possible to synthesize and implant an entire genome to create a living cell, the challenge of constructing a working blueprint for the first truly minimal synthetic organism is more important than ever. Here we review the significant progress made in the design and creation of a minimal organism. We discuss how comparative genomes, gene essentiality data, naturally small genomes, and metabolic modeling are all being applied to produce a catalogue of the biological functions essential for life. We compare the minimal gene sets from three published sources with functions identified in 13 existing gene essentiality datasets. We examine how genome‐scale metabolic models have been applied to design a minimal metabolism for growth in simple and complex media. Additionally, we survey the progress of efforts to construct a minimal organism, either through implementation of combinatorial deletions in Bacillus subtilis and Escherichia coli or through the synthesis and implantation of synthetic genomes.
The virus as metabolic engineer
Authors: Maynard Nathaniel D. , Gutschow Miriam V. , Birch Elsa W. , Covert Markus W. 
Published: July 2010

AbstractRecent genome‐wide screens of host genetic requirements for viral infection have reemphasized the critical role of host metabolism in enabling the production of viral particles. In this review, we highlight the metabolic aspects of viral infection found in these studies, and focus on the opportunities these requirements present for metabolic engineers. In particular, the objectives and approaches that metabolic engineers use are readily comparable to the behaviors exhibited by viruses during infection. As a result, metabolic engineers have a unique perspective that could lead to novel and effective methods to combat viral infection.
Co‐encapsulation of anti‐BCR‐ABL siRNA and imatinib mesylate in transferrin receptor‐targeted sterically stabilized liposomes for chronic myeloid leukemia treatment
Authors: Mendonça Liliana S. , Moreira João N. , de Lima Maria C. Pedroso , Simões Sérgio 
Published: July 2010

AbstractChronic myeloid leukemia (CML) is triggered by the BCR‐ABL oncogene. Imatinib is the first‐line treatment of CML; however imatinib resistance and intolerance have been detected in many patients. Therefore, new therapeutic approaches are required. The present work aimed at the development and application of transferrin receptor (TrfR) targeted liposomes co‐encapsulating anti‐BCR‐ABL siRNA and imatinib at different molar ratios. The encapsulation yields and drug loading of each molecule was evaluated. Anti‐leukemia activity of the developed formulations co‐encapsulating siRNA and imatinib and of the combination of Trf‐liposomes carrying siRNA and free imatinib under two different treatment schedules of pre‐sensitization was assessed. The results obtained demonstrate that the presence of imatinib significantly decreases the encapsulation yields of siRNA, whereas imatinib encapsulation yields are increased by the presence of siRNA. Cytotoxicity assays demonstrate that the formulations co‐encapsulating siRNA and imatinib promote a 3.84‐fold reduction on the imatinib IC50 (from 3.49 to 0.91 µM), whereas a 8.71‐fold reduction was observed for the pre‐sensitization protocols (from 42.7 to 4.9 nM). It was also observed that the formulations with higher siRNA to imatinib molar ratios promote higher cell toxicity. Thus, the present work describes a novel triple targeting strategy with one single system: cellular targeting (through the targeting ligand, transferrin) and molecular targeting at the BCR‐ABL mRNA and Bcr‐Abl protein level. Biotechnol. Bioeng. 2010;107: 884–893. © 2010 Wiley Periodicals, Inc.
Production of succinic acid at low pH by a recombinant strain of the aerobic yeast Yarrowia lipolytica
Authors: Yuzbashev Tigran V. , Yuzbasheva Evgeniya Y. , Sobolevskaya Tatiana I. , Laptev Ivan A. , Vybornaya Tatiana V. , Larina Anna S. , Matsui Kazuhiko , Fukui Keita , Sineoky Sergey P. 
Published: July 2010

AbstractBiotechnological production of weak organic acids such as succinic acid is most economically advantageous when carried out at low pH. Among naturally occurring microorganisms, several bacterial strains are known to produce considerable amounts of succinic acid under anaerobic conditions but they are inefficient in performing the low‐pH fermentation due to their physiological properties. We have proposed therefore a new strategy for construction of an aerobic eukaryotic producer on the basis of the yeast Yarrowia lipolytica with a deletion in the gene coding one of succinate dehydrogenase subunits. Firstly, an original in vitro mutagenesis‐based approach was proposed to construct strains with Ts mutations in the Y. lipolytica SDH1 gene. These mutants were used to optimize the composition of the media for selection of transformants with the deletion in the Y. lipolytica SDH2 gene. Surprisingly, the defects of each succinate dehydrogenase subunit prevented the growth on glucose but the mutant strains grew on glycerol and produced succinate in the presence of the buffering agent CaCO3. Subsequent selection of the strain with deleted SDH2 gene for increased viability allowed us to obtain a strain capable of accumulating succinate at the level of more than 45 g L−1 in shaking flasks with buffering and more than 17 g L−1 without buffering. The possible effect of the mutations on the utilization of different substrates and perspectives of constructing an industrial producer is discussed. Biotechnol. Bioeng. 2010;107:673–682. © 2010 Wiley Periodicals, Inc.
Cre recombinase‐mediated site‐specific modification of a cellular genome using an integrase‐defective retroviral vector
Authors: Huang Shuohao , Kawabe Yoshinori , Ito Akira , Kamihira Masamichi 
Published: July 2010

AbstractRetroviral integrase is an enzyme responsible for the integration of retroviruses. A single mutation in the integrase core domain can severely compromise its integration ability, leading to the accumulation of circular retroviral cDNA in the nuclei of infected cells. We therefore attempted to use those cDNA as substrates for Cre recombinase to perform a recombinase‐mediated cassette exchange (RMCE), thereby targeting retroviral vectors to a predetermined site. An expression unit containing a promoter, an ATG codon and marker genes (hygromycin resistance gene and red fluorescent protein gene) flanked by wild‐type and mutant loxP sites was first introduced into cellular chromosome to build founder cell lines. We then constructed another plasmid for the production of integrase‐defective retroviral vectors (IDRV), which contains an ATG‐deficient neomycin resistance gene and green fluorescent protein gene, flanked by a compatible pair of loxPs. After providing founder cells with Cre and infecting with IDRV later, effective RMCE occurred, resulting in the appearance of G418‐resistant colonies and a change in the color of fluorescence from red to green. Southern blot and PCR analyses on selected clones further confirmed site‐specific recombination. The successful substitution of the original viral integration machinery with a non‐viral mechanism could expand the application of retroviral vectors. Biotechnol. Bioeng. 2010;107:717–729. © 2010 Wiley Periodicals, Inc.
Using partition designs to enhance purification process understanding
Authors: Pieracci John , Perry Leonard , Conley Lynn 
Published: July 2010

AbstractCharacterization of purification processes by identifying significant input parameters and establishing predictive models is vital to developing robust processes. Current experimental design approaches restrict analysis to one process step at a time, which can severely limit the ability to identify interactions between process steps. This can be overcome by the use of partition designs which can model multiple, sequential process steps simultaneously. This paper presents the application of partition designs to a monoclonal antibody purification process. Three sequential purification steps were modeled using both traditional experimental designs and partition designs and the results compared as a proof of concept study. The partition and traditional design approaches identified the same input parameters within each process step that significantly affected the product quality output examined. The partition design also identified significant interactions between input parameters across process steps that could not be uncovered by the traditional approach. Biotechnol. Bioeng. 2010;107: 814–824. © 2010 Wiley Periodicals, Inc.