bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of polyphosphazene elastomer on the compatibility and properties of PES/TLCP composites
Authors: Bose Saswata , Mukherjee Madhumita , Das Chapal K. , Saxena Arvind K. 
Published: March 2009

AbstractIn this article, the chemistry of interfacial adhesion between different additive systems has been dealt with to develop a high performance nanocomposite and in the process, a comprehensive study on the reinforcing effect of nanosilica has been carried out. The base polymer was considered as the blends of Poly ethersulfone (PES) and thermotropic liquid crystalline polymer (TLCP). A novel polymeric compatibilizer, polyphosphazene elastomer, has been utilized and the interchain crosslinking has been explained. Results of experimental investigations demonstrate that the nanofillers play an important role in reducing the interfacial tension. However, the presence of Polyphosphazene elastomer, acted as compatibilizer further reducing the interfacial tension through the inter‐molecular interaction. The nanocomposites, thus developed, have better thermal stability and improved rheological properties. In addition, it has also been observed that Polyphosphazene elastomer impart flexibility in the composite. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Agro‐wastes: Mechanical and physical properties of resin impregnated oil palm trunk core lumber
Authors: Abdul Khalil H.P.S. , Bhat Aamir H. , Jawaid Mohammad , Amouzgar Parisa , Ridzuan R. , Said M.R. 
Published: March 2009

AbstractAgro‐wastes, oil palm trunk core or sap was utilized for the production of new palm‐wood material using phenol formaldehyde resin as a matrix. The kiln‐dried (moisture content 10%) oil palm trunk was impregnated with phenol formaldehyde resin using a high power vacuum pump. The oil palm trunk core lumber (OPTCL) was loaded with different percentages of phenol formaldehyde (PF) resin. The mechanical properties (tensile, flexural, and impact) and physical properties (water absorption and density) were studied and compared with rubberwood. Testing of mechanical and physical properties was done according to the ASTM standard. The morphology of the resin loaded OPTCL was analyzed by using Scanning Electron Microscopy (SEM). In general, the result showed that impregnated OPTCL exhibited good mechanical and physical properties when compared with untreated oil palm trunk core (OPTCL with 0% resin content) and rubberwood. Tensile and flexural strength of OPTCL increased with the increase in the resin content up to 15% and showed a decreasing trend with the increase in the loading percentage beyond 15%.The impact strength also increased with the increase in the resin content from 5% to 15%. However, impregnated OPTCL with 15% resin loading showed lower water absorption uptake as compared with the other composite materials and rubberwood. SEM micrograph confirmed that the resin was impregnated efficiently within the pores of OPTCL fibers. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Bearing strength of pin‐connected polymer composites subjected to dynamic loading
Authors: Yilmaz Taner , Sinmazcelik Tamer 
Published: March 2009

AbstractIn this study, static load bearing strength of pin‐connected carbon fiber‐reinforced polyphenylenesulphide (PPS) composites that have [(0°/90°)]3s stacking sequence was investigated. Firstly, the samples were loaded dynamically, and then the same samples were loaded statically. The results obtained from this sequential experiment were compared with the results obtained from samples that were loaded only statically. In addition, the fatigue life and failure mechanisms were investigated with respect to the selection of the geometrical parameters. Dynamic and static loading experiments were performed according to the ASTM STP 749 and ASTM D953 standards, respectively. To obtain optimum load bearing values, the ratio of distance between the edge and hole center to hole diameter (E/D) and ratio of sample width to hole diameter (W/D) has been systematically changed. According to the experimental results, maximum load bearing values have been obtained when E/D ratio was equal to 2. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Study on superabsorbent composite XXV. Synthesis, characterization, and swelling behaviors of poly(acrylic acid‐co‐N‐acryloylmorpholine)/attapulgite superabsorbent composites
Authors: Zhang Junping , Liu Yin , Wang Aiqin 
Published: March 2009

AbstractIn this work, a novel poly(acrylic acid‐co‐N‐acryloylmorpholine)/attapulgite superabsorbent composite was prepared by graft copolymerization among acrylic acid, N‐acryloylmorpholine and attapulgite in aqueous solution, using N,N′‐methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator. The result from FTIR spectra showed that OH of attapulgite participated in graft copolymerization with acrylic acid and N‐acryloylmorpholine. Proper monomer ratio and atapulgite content could form a loose surface, and improve reswelling ability and initial swelling rate. The buffer action of the COOH and COO− groups in the superabsorbent composite keeps the water absorbency a rough constant in the pH range of 4.4–9.6. Both polarity and structure of an organic solvent are responsible for the phase transition point of the superabsorbent composite. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Preparation, morphology, and adhesive and mechanical properties of ultrahigh‐molecular‐weight polyethylene/SiO2 nanocomposite fibers
Authors: Zhang Yi , Yu Junrong , Zhou Chengjun , Chen Lei , Hu Zuming 
Published: March 2009

AbstractA simple treatment approach has been performed to achieve enhanced surface properties of ultrahigh‐molecular‐weight polyethylene (UHMWPE) fibers by incorporation of nano‐silicon dioxide (SiO2) in the presence of silane coupling agent during gel‐spinning process. The SiO2‐treated UHMWPE (UHMWPE/SiO2) nanocomposite fibers with different nano‐SiO2 compositions were characterized with Fourier transform infrared spectra, scanning electron microscopy, and wide‐angle X‐ray diffraction, and their interfacial adhesion and mechanical properties were also investigated. The nano‐SiO2 can be trapped on the surface of the fibers to form rough surface for UHMWPE/SiO2 fibers, and diffused into the inner of fibers to induce the lower crystal sizes and higher crystallinity of polyethylene in UHMWPE/SiO2 fibers. The resulting UHMWPE/SiO2 fibers therefore exhibit a dramatic enhancement in the adhesive properties because of the combination of rougher surface compared with those of UHMWPE fiber and polar groups absorbed on the surface of fibers. The mechanical properties of UHMWPE/SiO2 nanocomposite fibers are enhanced simultaneously because of the influence of nano‐SiO2 on the structure of UHMWPE crystalline regions and fibrils. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers
Proteomic analysis of cytoplasmic and surface proteins from yeast cells, hyphae, and biofilms of Candida albicans
Authors: Martínez‐Gomariz Montserrat , Perumal Palani , Mekala Satish , Nombela César , Chaffin W. LaJean , Gil Concha 
Published: March 2009

AbstractCandida albicans is a human commensal and opportunistic pathogen that participates in biofilm formation on host surfaces and on medical devices. We used DIGE analysis to assess the cytoplasmic and non‐covalently attached cell‐surface proteins in biofilm formed on polymethylmethacrylate and planktonic yeast cells and hyphae. Of the 1490 proteins spots from cytoplasmic and 580 protein spots from the surface extracts analyzed, 265 and 108 were differentially abundant respectively (>1.5‐fold, p <0.05). Differences of both greater and lesser abundance were found between biofilms and both planktonic conditions as well as between yeast cells and hyphae. The identity of 114 cytoplasmic and 80 surface protein spots determined represented 73 and 25 unique proteins, respectively. Analyses showed that yeast cells differed most in cytoplasmic profiling while biofilms differed most in surface profiling. Several processes and functions were significantly affected by the differentially abundant cytoplasmic proteins. Particularly noted were many of the enzymes of respiratory and fermentative pentose and glucose metabolism, folate interconversions and proteins associated with oxidative and stress response functions, host response, and multi‐organism interaction. The differential abundance of cytoplasmic and surface proteins demonstrated that sessile and planktonic organisms have a unique profile.
Targeted serum glycoproteomics for the discovery of lung cancer‐associated glycosylation disorders using lectin‐coupled ProteinChip arrays
Authors: Ueda Koji , Fukase Yu , Katagiri Toyomasa , Ishikawa Nobuhisa , Irie Shinji , Sato Taka‐Aki , Ito Hiroyuki , Nakayama Haruhiko , Miyagi Yohei , Tsuchiya Eiju , Kohno Nobuoki , Shiwa Mieko , Nakamura Yusuke , Daigo Yataro 
Published: March 2009

AbstractTo screen for glycoproteins showing aberrant sialylation patterns in sera of cancer patients and apply such information for biomarker identification, we performed SELDI‐TOF MS analysis coupled with lectin‐coupled ProteinChip arrays (Jacalin or SNA) using sera obtained from lung cancer patients and control individuals. Our approach consisted of three processes (i) removal of 14 abundant proteins in serum, (ii) enrichment of glycoproteins with lectin‐coupled ProteinChip arrays, and (iii) SELDI‐TOF MS analysis with acidic glycoprotein‐compatible matrix. We identified 41 protein peaks showing significant differences (p<0.05) in the peak levels between the cancer and control groups using the Jacalin‐ and SNA‐ProteinChips. Among them, we identified loss of Neu5Ac (α2,6) Gal/GalNAc structure in apolipoprotein C‐III (apoC‐III) in cancer patients through subsequent MALDI‐QIT‐TOF MS/MS. Furthermore, subsequent validation experiments using an additional set of 60 lung adenocarcinoma patients and 30 normal controls demonstrated that there is a higher frequency of serum apoC‐III with loss of α2,6‐linkage Neu5Ac residues in lung cancer patients compared to controls. Our results have demonstrated that lectin‐coupled ProteinChip technology allows the high‐throughput and specific recognition of cancer‐associated aberrant glycosylations, and implied a possibility of its applicability to studies on other diseases.
Sequencing of the thirteen structurally isomeric quartets of N‐terminal dipeptide motifs in peptides by collision‐induced dissociation
Authors: Winter Dominic , Lehmann Wolf D. 
Published: March 2009

AbstractN‐terminal sequencing of protonated peptides is challenging, since each b2 ion represents two sequence isomers, e.g., NE and EN. Additionally the occurrence of compositional isomers, such as NE and QD, further increases the number of isomers to four (NE, EN, QD, DQ). This leads to a subset of 13 b2 ion masses where each value represents four individual species. The b2 ions within such a quartet are characterized by the same elemental composition. To test the utility of CID for differentiation of isomeric b2 ions, the CID spectra of 52 small synthetic peptides were recorded, representing the 13 isomeric b2 ion quartets, which may be formed from unmodified amino acid residues. The CID spectra of protonated peptides containing these quartets were carefully inspected for N‐terminal sequence information. Below the m/z value of the b2 ion, individual differences were found in the b2 fragment ion signatures (neutral loss of CO, H2O, NH3, and other less common units). Recognition of N and Q in second position from the N‐terminus is based on c1 ion formation. Relative intensities of immonium ions were also used for differentiation between sequence isomers. In the complementary high‐mass regions above the m/z value of the ymax‐2 ion, individual differences were observed in the formation of ymax‐1, xmax‐1 and zmax‐1 ions, which could be correlated to the complementary low‐mass ions. In summary, de novo sequencing of the N‐terminal dipeptide motif is feasible by considering all available sequence information present in CID spectra of protonated peptides.
Exploring the priming mechanism of liver regeneration: proteins and protein complexes
Authors: Deng Xinyu , Li Wenrui , Chen Ning , Sun Yanwei , Wei Handong , Jiang Ying , He Fuchu 
Published: March 2009

AbstractThe liver has the ability to restore its functional capacity following injury or resection and the priming of liver regeneration is a complex process that has not been completely elucidated. In the current research, to further reveal the priming mechanism of liver regeneration, hepatocyte total protein and hepatocyte cytosol of the rats at 4 h after 2/3 partial hepatectomy (PHx) were studied, respectively, by 2‐DE and 2‐D blue native gel electrophoresis. Seventeen unique differential proteins were identified in hepatocyte total protein samples. Nine differential protein complexes containing 41 protein components were identified in hepatocyte cytosol samples. For the first time, at the priming stage of liver regeneration, the variations of serine protease inhibitor 2c, sulfite oxidase and valosin‐containing protein (VCP) were presented and validated by Western blotting, and the VCP complex was further validated by antibody super‐shift experiments. The current results suggested that at 4 h after PHx, VCP complex was down‐regulated in hepatocyte cytosol, apoptosis pathways were inhibited, nuclear factor‐κB and interleukin 6 pathways worked together and triggered the liver regeneration.
Detection of allergen specific immunoglobulins by microarrays coupled to microfluidics
Authors: Cretich Marina , Di Carlo Gabriele , Giudici Cinzia , Pokoj Sven , Lauer Iris , Scheurer Stephan , Chiari Marcella 
Published: March 2009

AbstractAllergen microarrays are under development for a component‐resolved diagnosis of Type I (IgE‐mediated) allergies. Here we report an improved microarray coupled to microfluidics for the detection of allergen specific immunoglobulin E (IgE). The signal intensity for IgE detection in serum has been improved by using glass slides coated with a novel poly[DMA‐co‐NAS] brush copolymer which is able to immobilize allergens in their native conformation and by carrying out the incubation step in dynamic conditions. The assay, fully automated, was performed in a microcell, using a software‐controlled fluidic processor, to bring assay reagents on the surface of the array. Microfluidics turns the binding between serum immunoglobulins and immobilized allergens from a diffusion‐limited to a kinetic‐limited process by ensuring an efficient mixing of serum samples on the surface of the microarray. As a result of this, the binding of high affinity IgE antibodies is enhanced whereas that of low affinity IgG antibodies, which are present at higher concentration, is impaired paving the way to more accurate and sensitive results.
Proteomic changes in the crucian carp brain during exposure to anoxia
Authors: Smith Richard W. , Cash Phil , Ellefsen Stian , Nilsson Göran E. 
Published: March 2009

AbstractDuring exposure to anoxia, the crucian carp brain is able to maintain normal overall protein synthesis rates. However, it is not known if there are alterations in the synthesis or expression of specific proteins. This investigation addresses this issue by comparing the normoxic and anoxic brain proteome. Nine proteins were found to be reduced by anoxia. Reductions in the glycolytic pathway proteins creatine kinase, fructose biphosphate aldolase, glyceraldehyde‐3‐phosphate dehydrogenase, triosephosphate isomerase and lactate dehydrogenase reflect the reduced production and requirement for adenosine tri‐phosphate during anoxia. In terms of neural protection, voltage‐dependent anion channel, a protein associated with neuronal apoptosis, was reduced, along with gefiltin, a protein associated with the subsequent need for neuronal repair. Additionally the expression of proteins associated with neural degeneration and impaired cognitive function also declined; dihydropyrimidinase‐like protein‐3 and vesicle amine transport protein‐1. One protein was found to be increased by anoxia; pre‐proependymin, the precursor to ependymin. Ependymin fulfils multiple roles in neural plasticity, memory formation and learning, neuron growth and regeneration, and is able to reverse the possibility of apoptosis, thus further protecting the anoxic brain.
Anthracene‐ and thiophene‐containing MEH‐PPE‐PPVs: Synthesis and study of the effect of the aromatic ring position on the photophysical and electrochemical properties
Authors: Wild Andreas , Egbe Daniel A. M. , Birckner Eckhard , Cimrová Vera , Baumann Reinhard , Grummt Ulrich‐Walter , Schubert Ulrich S. 
Published: March 2009

AbstractThis contribution reports on the synthesis and characterization of thiophene‐ (P1, P2, and P3) and anthracene‐ (P4 and P5) containing PPE‐PPV copolymers. The thermostable, soluble and film‐forming polymers were fully characterized by NMR, IR and ELEM. ANAL.; they exhibit high molar masses with polydispersity indices below 2.5. The position of the thiophene in the polymeric backbone has insignificant influence on the spectroscopic properties of the polymers. In contrast, the anthracene‐containing polymers reveal position dependent optical properties. A constant bathochromic shift of 50 nm was observed going from P4, where anthracene is surrounded by two double bonds, to P5, where anthracene is at the bridge between a triple bond and a double bond, as well as from P5 to P6 where anthracene is surrounded by two triple bonds. This correlates to the decrease of the observed anthracene band around 255 nm going from P4 through P5 to P6, amounting to the degree of contribution of the anthracene unit to the main chain conjugation. The phenomenon known as CN‐PPV effect was observed in the case of P4 [Φf (solution) = 3%, Φf (solid) = 13%]. Electrochemical studies carried out under absolute inert conditions revealed lower electrochemical band gap energies, E, than E. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2243–2261, 2009
Polybenzimidazoles tethered with N‐phenyl 1,2,4‐triazole units as polymer electrolytes for fuel cells
Authors: Potrekar R. A. , Kulkarni M. P. , Kulkarni R. A. , Vernekar S. P. 
Published: March 2009

AbstractPolybenzimidazole (PBI) polymers tethered with N‐phenyl 1,2,4‐triazole (NPT) groups were prepared from a newly synthesized aromatic diacid, 3′‐(4‐phenyl‐4H‐1,2,4‐triazole‐3,5‐diyl) dibenzoic acid (PTDBA). The obtained polymers show superior thermal and chemical stability and good solubility in many aprotic solvents. The inherent viscosities of all polymers were around 1 dL/g. They exhibit high thermal stability with initial decomposition temperature ranging from 515 to 530 °C, high glass transition temperature ranging from 375 to 410 °C, and good mechanical properties with tensile stress in the range of 66–98 MPa and modulus 1897–2600 MPa. XRD analysis indicates that these polymers are amorphous in nature. Physicochemical properties such as water and phosphoric acid‐uptake, oxidative stability, and proton conductivity of membranes of these polymers have also been determined. The proton conductivity ranged from 4.7 × 10−3 to 1.8 × 10−2 S cm−1 at 175 °C in dry conditions. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2289–2303, 2009
Highly stable electrochromic polyamides based on N,N‐bis(4‐aminophenyl)‐N′,N′‐bis(4‐tert‐butylphenyl)‐1,4‐phenylenediamine
Authors: Hsiao Sheng‐Huei , Liou Guey‐Sheng , Wang Hui‐Min 
Published: March 2009

AbstractA new triphenylamine‐containing aromatic diamine monomer, N,N‐bis(4‐aminophenyl)‐N′,N′‐bis(4‐tert‐butylphenyl)‐1,4‐phenylenediamine, was synthesized by an established synthetic procedure from readily available reagents. A novel family of electroactive polyamides with di‐tert‐butyl‐substituted N,N,N′,N′‐tetraphenyl‐1,4‐phenylenediamine units were prepared via the phosphorylation polyamidation reactions of the newly synthesized diamine monomer with various aromatic or aliphatic dicarboxylic acids. All the polymers were amorphous with good solubility in many organic solvents, such as N‐methyl‐2‐pyrrolidinone (NMP) and N,N‐dimethylacetamide, and could be solution‐cast into tough and flexible polymer films. The polyamides derived from aromatic dicarboxylic acids had useful levels of thermal stability, with glass‐transition temperatures of 269–296 °C, 10% weight‐loss temperatures in excess of 544 °C, and char yields at 800 °C in nitrogen higher than 62%. The dilute solutions of these polyamides in NMP exhibited strong absorption bands centered at 316–342 nm and photoluminescence maxima around 362–465 nm in the violet‐blue region. The polyamides derived from aliphatic dicarboxylic acids were optically transparent in the visible region and fluoresced with a higher quantum yield compared with those derived from aromatic dicarboxylic acids. The hole‐transporting and electrochromic properties were examined by electrochemical and spectro‐electrochemical methods. Cyclic voltammograms of the polyamide films cast onto an indium‐tin oxide‐coated glass substrate exhibited two reversible oxidation redox couples at 0.57–0.60 V and 0.95–0.98 V versus Ag/AgCl in acetonitrile solution. The polyamide films revealed excellent elcterochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and blue oxidized forms at applied potentials ranging from 0.0 to 1.2 V. These anodically coloring polymeric materials showed interesting electrochromic properties, such as high coloration efficiency (CE = 216 cm2/C for the green coloring) and high contrast ratio of optical transmittance change (ΔT%) up to 64% at 424 nm and 59% at 983 nm for the green coloration, and 90% at 778 nm for the blue coloration. The electroactivity of the polymer remains intact even after cycling 500 times between its neutral and fully oxidized states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2330–2343, 2009
Pegylated thermally responsive block copolymer micelles and nanogels via in situ RAFT aqueous dispersion polymerization
Authors: Rieger Jutta , Grazon Chloé , Charleux Bernadette , Alaimo David , Jérôme Christine 
Published: March 2009

AbstractA very straightforward approach was developed to synthesize pegylated thermoresponsive core‐shell nanoparticles in a minimum of steps, directly in water. It is based on RAFT‐controlled radical crosslinking copolymerization of N,N‐diethylacrylamide (DEAAm) and N,N′‐methylene bisacrylamide (MBA) in aqueous dispersion polymerization. Because DEAAm is water‐soluble and poly(N,N‐diethylacrylamide) (PDEAAm) exhibits a lower critical solution temperature at 32 °C, the initial medium was homogeneous, whereas the polymer formed a separate phase at the reaction temperature. The first macroRAFT agent was a surface‐active trithiocarbonate based on a hydrophilic poly(ethylene oxide) block and a hydrophobic dodecyl chain. It was further extented with N,N‐dimethylacrylamide (DMAAm) to target macroRAFT agents with increasing chain length. All macroRAFT agents provided excellent control over the aqueous dispersion homopolymerization of DEAAm. When they were used in the radical crosslinking copolymerization of DEAAm and MBA, the stability and size of the resulting gel particles were found to depend strongly on the chain length of the macroRAFT agent, on the concentrations of both the monomer and the crosslinker, and on the process (one step or two steps). The best‐suited experimental conditions to reach thermosensitive hydrogels with nanometric size and well‐defined surface properties were determined. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2373–2390, 2009