bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical properties and EMI shielding behavior of highly thermally stable polyaniline/colloidal graphite composites
Authors: Saini Parveen , Choudhary Veena , Dhawan S. K. 
Published: January 2009

AbstractA hybrid approach has been adopted by using a combination of colloidal graphite (CG) as a conducting filler, 5‐lithium sulfoisophthalic (LiSIPA) acid as a dopant, and polyaniline (PANI) as a matrix to prepare LiSIPA doped PANI–CG composites. The thermal stability (∼300°C) and electrical conductivity (67.4 S/cm at 17.4% CG content) have been improved significantly as compared to PANI doped with conventional inorganic dopants like HCl or H2SO4 (130–150°C). The maximum shielding effectiveness value was found to be −39.7 dB. X‐ray diffraction and infrared spectroscopy showed a systematic shifting of the characteristic peaks and bands with increase in the amount of CG, which indicates significant interaction exists between CG and PANI. The UV–Vis spectra showed the characteristic bands of PANI, with a shift to shorter wavelength with increase in the CG content. The interaction mechanism between doped PANI and CG in the resultant composites has been proposed. Copyright © 2009 John Wiley & Sons, Ltd.
Study on combustion property and synergistic effect of intumescent flame retardant styrene butadiene rubber with metallic oxides
Authors: Liu QingQing , Song Lei , Lu HongDian , Hu Yuan , Wang ZhengZhou , Zhou Shun 
Published: January 2009

AbstractEffect of metallic oxides on flame retardancy and the thermal stability of styrene butadiene rubber (SBR) composites based on ammonium polyphosphate (APP) and pentaerythritol (PER) was studied by the limiting oxygen index (LOI), UL 94, the cone calorimeter tests, and thermogravimetry analysis (TGA), respectively. Scanning electron microscopy (SEM) and wide‐angle X‐ray diffraction (WAXD) were used to analyze the morphological structure and the component of the residue chars formed from the SBR composites accordingly. The addition of zirconium dioxide (ZrO2) at a loading of 3.4 phr could improve the UL 94 test rating of the composite to V‐0. The TGA data illustrated that the metallic oxides could enhance the thermal stability of the SBR/Intumescent flame retardant additives (IFRs) composites at high temperature and increase the residue. Cone calorimeter test gave much clear evidence that the incorporation of ZrO2 into SBR/IFRs composites resulted in the significant deduction of the heat release rate (HRR) values, and the SEM images showed that the char layers of the composites containing the metallic oxides became more compact. From the WAXD pattern, zirconium phosphate (ZrP2O7) may be formed by the reaction between ZrO2 and APP. Due to the addition of ZrO2 and the formation of ZrP2O7, the flame retardancy of the composite was improved. Copyright © 2009 John Wiley & Sons, Ltd.
Conductive mechanism of antistatic poly(ethylene terephthalate)/ZnOw composites
Authors: Chen Ke , Xiong Chuanxi , Li Liubin , Zhou Liu , Lei Youan , Dong Lijie 
Published: January 2009

AbstractAntistatic composites of poly(ethylene terephthalate) (PET) and tetrapod‐shaped ZnO whisker (ZnOw), the surface of which was treated with a coupling agent, were prepared by melt‐mixing using a twin screw extruder. The structure and morphology of the blends were examined by FTIR and SEM. Antistatic performance and the effect of ZnOw loading levels were investigated. The conductive mechanism of PET/ZnOw composites is presented, which can be classified into tunnel effect, discharging effect at the pinpoint and conductive network. The simple formula of critical volume fraction (vc) for ZnOw forming conductive network is proposed, based on the actual processing conduction. Comparison of the theory value to the experimental data showed a close agreement. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers
Highly sensitive saturation labeling reveals changes in abundance of cell cycle‐associated proteins and redox enzyme variants during oocyte maturation in vitro
Authors: Berendt Frank J. , Fröhlich Thomas , Bolbrinker Patrick , Boelhauve Marc , Güngör Tuna , Habermann Felix A. , Wolf Eckhard , Arnold Georg J. 
Published: January 2009

AbstractOocyte maturation is a complex process and a critical issue in assisted reproduction techniques (ART) in humans and other mammals. We used a sensitive 2‐D DIGE saturation labeling approach including an internal pooled standard for quantitative proteome profiling of immature versus in vitro matured bovine oocytes in six independent samples. The study comprised 48 2D gel images representing 24 DIGE experiments. From 250 ng sample analyzed per gel, quantitative analysis revealed an average of 2244 spots in pH 4–7 images and 1291 spots in pH 6–9 images. Thirty‐eight spots with different intensities were detected in total. Spots of a preparative gel from 2200 oocytes were identified by nano‐LC‐MS/MS analysis. The ten spots which could be unambiguously identified include the Ca2+‐binding protein translationally controlled tumor protein, enzymes of the Krebs and pentose phosphate cycles, clusterin, 14‐3‐3 ϵ, elongation factor‐1 gamma, and redox enzymes such as polymorphic forms of GST Mu 5 and peroxiredoxin‐3. The cellular distribution of two proteins was determined by confocal laser scanning microscopy. The interesting protein candidates identified by this study may help to improve the in vitro maturation process in order to increase the rate of successful in vitro fertilization and other ART in cattle and other mammals.
A comprehensive evaluation of imidazole‐zinc reverse stain for current proteomic researches
Authors: Lin Ching‐Yu , Wang Vinchi , Shui Hao‐Ai , Juang Rong‐Huay , Hour Ai‐Ling , Chen Pei‐Sing , Huang Hui‐Ming , Wu Szu‐Yu , Lee Jen‐Chieh , Tsai Tzung‐Lin , Chen Han‐Min 
Published: January 2009

AbstractIn this paper, we comprehensively evaluated the capability of imidazole‐zinc reverse stain (ZN) in comparative proteomics. Three commonly used protein gel staining methods, including silver (SN), SYPRO Ruby (SR), and CB stain were investigated alongside for comparison purpose. A transparency scanning procedure, which may deliver more even and contrasting gel images, was found best for documenting ZN stained gels. Our results showed that ZN was more sensitive than SN, SR, and CB. It may reveal as few as 1.8 ng of proteins in a gel. Moreover, ZN was found to provide a linear dynamic range of staining for revealing proteins up to 140 ng, and show an insignificant staining preference. To analyze a ZN stained 2‐D gel image that generally comprises an apparent but even background, the Melanie 4 software was found more suitable than others. Furthermore, ZN demonstrated an equivalent or better MS compatibility than the other three staining methods. Intense and comprehensive MS profiles were frequently observed for ZN stained gel spots. Approximate two‐third of ZN stained gel spots were successfully identified for protein identities. Taken together, our results suggest that the prompt, cost effective and versatile ZN is well suited for current proteomic researches.
Yeast protein expression profile during acetic acid‐induced apoptosis indicates causal involvement of the TOR pathway
Authors: Almeida Bruno , Ohlmeier Steffen , Almeida Agostinho J. , Madeo Frank , Leão Cecília , Rodrigues Fernando , Ludovico Paula 
Published: January 2009

AbstractAlthough acetic acid has been shown to induce apoptosis in yeast, the exact apoptotic mechanisms remain unknown. Here, we studied the effects of acetic acid treatment on yeast cells by 2‐DE, revealing alterations in the levels of proteins directly or indirectly linked with the target of rapamycin (TOR) pathway: amino‐acid biosynthesis, transcription/translation machinery, carbohydrate metabolism, nucleotide biosynthesis, stress response, protein turnover and cell cycle. The increased levels of proteins involved in amino‐acid biosynthesis presented a counteracting response to a severe intracellular amino‐acid starvation induced by acetic acid. Deletion of GCN4 and GCN2 encoding key players of general amino‐acid control (GAAC) system caused a higher resistance to acetic acid indicating an involvement of Gcn4p/Gcn2p in the apoptotic signaling. Involvement of the TOR pathway in acetic acid‐induced apoptosis was also reflected by the higher survival rates associated to a terminal deoxynucleotidyl transferase‐mediated dUTP nick end labeling (TUNEL)‐negative phenotype and lower reactive oxygen species levels of Δtor1 cells. In addition, deletion mutants for several downstream mediators of the TOR pathway revealed that apoptotic signaling involves the phosphatases Pph21p and Pph22p but not Sit4p. Altogether, our results indicate that GAAC and TOR pathways (Tor1p) are involved in the signaling of acetic acid‐induced apoptosis.
Identification of secreted proteins regulated by cAMP in glioblastoma cells using glycopeptide capture and label‐free quantification
Authors: Hill Jennifer J. , Moreno Maria J. , Lam Jean C. Y. , Haqqani Arsalan S. , Kelly John F. 
Published: January 2009

AbstractExposure of glioblastoma U87MG cells to a cAMP analog leads to a decrease in proliferation, invasion, and angiogenic potential. Here, we apply a label‐free MS‐based approach to identify formerly N‐linked glycopeptides that change in abundance upon cAMP treatment. Over 150 unique glycopeptides in three biological repetitions were quantified, leading to the identification of 14 upregulated proteins and 21 downregulated proteins due to cAMP treatment. Of these, eight have been validated, either through comparison with microarray data or by Western blot. We estimate our ability to identify differentially expressed peptides at greater than 85% in a single biological repetition, while the analysis of multiple biological repetitions lowers the false positive rate to ∼2%. Many of the proteins identified in this study are involved in cell signaling and some, such as Tenascin C, Cathepsin L, Neuroblastoma suppressor of tumorigenicity, and AXL/UFO tyrosine–protein kinase receptor, have been previously shown to be involved in glioblastoma progression. We also identify several semitryptic peptides that increase in abundance upon cAMP treatment, suggesting that cAMP regulates protease activity in these cells. Overall, these results demonstrate the benefits of using a highly specific enrichment method for quantitative proteomic experiments.
Improved protein sequence coverage by on resin deglycosylation and cysteine modification for biomarker discovery
Authors: Kamada Haruhiko , Fugmann Tim , Neri Dario , Roesli Christoph 
Published: January 2009

AbstractMembrane proteins and secreted factors (soluble proteins or extracellular matrix components) are the targets of most monoclonal antibodies, which are currently in clinical development. These proteins are frequently post‐translationally modified, e.g. by the formation of disulfide bonds or by glycosylation, which complicates their identification using proteomics technologies. Here, we describe a novel methodology for the on resin deglycosylation and cysteine modification of proteins after in vitro, in vivo or ex vivo biotinylation. Biotinylated proteins are captured on streptavidin resin and all subsequent modifications, as well as the proteolytic digestion, which yields peptides for MS analysis, are performed on resin. Using biotinylated bovine fetuin‐A as a test protein, an improvement in sequence coverage from 7.9 to 58.7% could be shown, including the identification of all three glycosylation sites. Furthermore, a complex mixture derived from the ex vivo biotinylation of vascular structures in human kidney with cancer obtained by perfusion after surgical resection revealed almost a doubling of sequence coverage for all checked proteins when analyzed by LC‐MALDI TOF/TOF.
Pharmacokinetics and Pharmacodynamics of Linezolid in Children With Cystic Fibrosis
Authors: Santos Roberto P. , Prestidge Claude B. , Brown Michael E. , Urbancyzk Brenda , Murphey Donald K. , Salvatore Christine M. , Jafri Hasan S. , McCracken George H. , Ahmad Naveed , Sanchez Pablo J. , Siegel Jane D. 
Published: January 2009

AbstractAlternative antimicrobial regimens are needed for treatment of methicillin‐resistant Staphylococcus aureus (MRSA)‐associated pulmonary exacerbations in children with cystic fibrosis (CF). There are no published pharmacokinetic (PK) and pharmacodynamic (PD) data for linezolid in children with CF.Objectives(1) To determine the PK and PD profile of linezolid among children with CF; (2) to characterize the effect of linezolid on MRSA infection; (3) to determine the effect of age and CF transmembrane regulator (CFTR) gene mutations on drug clearance.HypothesesLinezolid clearance is enhanced in children with CF requiring a higher dosage regimen. Age and CFTR gene mutations affect drug clearance.MethodsThis was a retrospective cohort study; medical records of children with MRSA‐associated pulmonary exacerbations treated with linezolid (10 mg/kg/dose IV every 8h) were reviewed. Linezolid peak and trough concentrations in serum were determined by high performance liquid chromatography, PK profiles determined using standard noncompartmental method, and PD indices were evaluated.Results10 children (mean ± SD, 10.2 ± 5.5 years) received 14 courses of linezolid at 10 ± 0.4 mg/kg/dose every 8h for 15.4 ± 3.2 days. Seven had homozygous ΔF508 CFTR mutation. Peak and trough linezolid concentrations varied widely (range, 8.4–20.5 and 0.1–11.5 mcg/mL respectively). The PK profile of children <10 years differed significantly from older patients (≥10 years). The PK indices of children with homozygous ΔF508 differed marginally from those with heterozygous CFTR mutations, but there were too few subjects to allow separation of age and CFTR mutations effect. No patient achieved the target PD ratio of AUC/MIC >80. MRSA persisted in sputum or throat culture after treatment with linezolid.ConclusionsAdditional PK and PD data are needed to optimize linezolid therapy in children with cystic fibrosis; it is likely that higher doses will be needed. Pediatr Pulmonol. 2009; 44:148–154. © 2009 Wiley‐Liss, Inc.
Analysis of oligomeric peroxides in synthetic triacetone triperoxide samples by tandem mass spectrometry
Authors: Sigman Michael E. , Clark C. Douglas , Painter Kimberly , Milton Chatham , Simatos Ekaterina , Frisch Jessica L. , McCormick Meghan , Bitter Julie L. 
Published: January 2009

AbstractOligomeric peroxides formed in the synthesis of triacetone triperoxide (TATP) have been analyzed by mass spectrometry utilizing both electrospray ionization (ESI) and chemical ionization (CI) to form sodiated adducts (by ESI) and ammonium adducts (by CI and ESI). Tandem mass spectrometry and deuterium isotopic labeling experiments have been used to elucidate the collision‐induced dissociation (CID) mechanisms for the adducts. The CID mechanisms differ for the sodium and ammonium adducts and vary with the size of the oligoperoxide. The sodium adducts of the oligoperoxides, H[OOC(CH3)2]nOOH, do not cyclize under CID, whereas the ammonium adducts of the smaller oligoperoides (n < 6) do form the cyclic peroxides under CID. Larger oligoperoxide adducts with both sodium and ammonium undergo dissociation through cleavage of the backbone under CID to form acyl‐ and hydroperoxy‐terminated oligomers of the general form CH3C(O)[OOC(CH3)2]xOOH, where x is an integer less than the original oligoperoxide degree of oligomerization. The oligoperoxide distribution is shown to vary batch‐to‐batch in the synthesis of TATP and the post‐blast distribution differs slightly from the distribution in the uninitiated material. The oligoperoxides are shown to be decomposed under gentle heating. Copyright © 2009 John Wiley & Sons, Ltd.
Exploiting spatial‐domain simplicity in spectral image analysis
Authors: Keenan Michael R. 
Published: January 2009

AbstractFull‐spectrum imaging is fast becoming a tool of choice for characterizing heterogeneous materials. Spectral images, which consist of a complete spectrum at each point in a spatial array, can be acquired from a wide variety of surface and microanalytical spectroscopic techniques. It is not uncommon that such spectral image data sets comprise tens of thousands of individual spectra, or more. Given the vast quantities of raw spectral data, factor analysis methods have proved indispensable for extracting the chemical information from these high‐dimensional data sets into a limited number of factors that represent the spectral and spatial characteristics of the sample's composition. It is well known that factor models suffer a ‘rotational ambiguity’, that is, there are an infinite number of factor models that will fit the data equally well. Thus, physically inspired constraints are often employed to derive relatively unique models that make the individual factors more easily interpreted by the practicing analyst. In the present work, we note that many samples undergoing spectral image analysis are ‘simple’ in the sense that only one or a few of the sample's constituents are present at any particular location. When this situation prevails, simplicity in the spatial domain can be exploited to make the resulting factor models more realistic. In particular, orthogonal rotation of the spatial‐domain vectors arising from singular value decomposition (SVD) of the spectral data matrix will be shown to be an effective method for making physically acceptable and easily interpretable estimates of the pure‐component spectra and abundances. Copyright © 2009 John Wiley & Sons, Ltd.
Micro/macrotribological properties of several nano‐scale ionic liquid films on modified silicon wafers
Authors: Zhu Min , Mo Yufei , Zhao Wenjie , Bai Mingwu 
Published: January 2009

AbstractThree kinds of alkylimidazolium base room temperature ionic liquids (RTILs) were synthesized and their nano‐scale lubricant films were prepared on modified silicon wafers by dip‐coating method. The thicknesses of these films were measured and their relationship between thickness and solution concentration was obtained. Their surface morphologies were observed and contact angles of water on these films were determined. The adhesions and friction coefficients of these films were detected by contact mode AFM. As comparison, their macrotribological properties were evaluated on a UMT‐2MT tribo‐tester. It was found that, in microscale, 1‐hexyl‐3‐methyl‐imidazolium hexafluorophosphate performed the best tribological properties, while in macroscale, its tribological properties were similar with that of 1‐hexyl‐3‐methyl‐imidazolium tetrafluoroborate and better than that of 1‐hexyl‐3‐methyl‐imidazolium adipate. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of the inhibitory effect of decreasing temperature on tribo‐oxidation behaviour of certain steel using EDS analysis
Authors: Wang Hongling , Yan Fengyuan 
Published: January 2009

AbstractIn order to clarify the influence of temperature below freezing point on the tribo‐oxidation of steel–steel friction pairs, tribological behaviour of certain steel from −55 °C to 20 °C was investigated using a ball‐on‐disk tribometer in a thermotank which could provide environment with constant temperature and humidity. The counterbody was a $\varphi$3 mm GCr15 steel ball. The normal load was 0.5 ∼ 2.5 N and the sliding velocity was 0.319 m/s. Worn surface on the steel, wear scar on the steel ball and wear debris were observed and analysed by SEM and EDS. It was found that the friction coefficient presents a sudden increase when the ambient temperature drop from 20 to − 10 °C. This is caused by decrease of relative humidity. The friction coefficient maintains the same value when the temperature change is between − 10 and −55 °C. A drop of temperature from 20 to −55 °C aggravated wear of the steel. Analysis on tribochemical reaction process indicates gradually weakened oxidation of wear debris along with a drop of temperature should account for the aggravation of wear. Furthermore, along with the drop in temperature, the worn surface became rougher and more structure fractures were formed on the friction track, which led to more severe abrasive wear of the steel. Drop of temperature increased abrasive wear but decreased adhesive wear. Copyright © 2008 John Wiley & Sons, Ltd.
Adsorption characteristic of self‐assembled corrole dimers on HOPG
Authors: Miao Xinrui , Gao Aimei , Hiroto Satoru , Shinokubo Hiroshi , Osuka Atsuhiro , Xin Hongliang , Deng Wenli 
Published: January 2009

AbstractOur study first focus on two types of corrole dimers oxidized and reduced forms on highly oriented pyrolytic graphite (HOPG) surface. Scanning tunneling microscopy (STM), X‐ray photoelectron spectroscopy (XPS) and contact angle measurement (CAM) were used to investigate the self‐assembled monolayers of corrole dimers adsorbed on HOPG surfaces at room temperature in air. XPS and CAM results have confirmed both two molecules adsorbed on an HOPG surface and formed self‐assembled films, and STM experiments found that the corrole dimers adsorbed on HOPG surfaces form similar lobes. The different stable space structure of the oxidized form molecule (OFM) and reduced form molecule (RFM), led to the diversity of the tetramer structural dimensions. The occurrence of molecular aggregations and assembly was controlled by the interactions between molecular–molecular and molecule–substrate. The electrostatic interactions between the molecules control the geometrical sizes and molecule–substrate interactions determine topographical shapes of the self‐assembled corrole dimers on HOPG surface. Copyright © 2009 John Wiley & Sons, Ltd.
A study on effects of TiB2 contents on reactive products and compressive strength of brazed CBN grains
Authors: Ding Wenfeng , Xu Jiuhua , Chen Zhenzhen , Cheng Ze , Fu Yucan 
Published: January 2009

AbstractThe composite fillers were prepared by means of mixing Ag‐Cu‐Ti alloy and TiB2 reinforcing particles. Experimental study was conducted on the chemical reaction and the reactive products at the interface between CBN grains and the composite filler. The compressive strength measurement of brazed CBN grains was performed. Results obtained show that the TiB2particles disperse uniformly in the filler layer. Great influence of TiB2particles is made on the quantity of the reactive products formed on the surface of brazed CBN grains. The destruction of the sharp edges of grains is restrained. Depending on the compact and fine reactive compounds, hard joining is realized for the CBN grain and the filler layer. When the content of TiB2particles in the composite filler is 8 wt%, the thermal damage of the brazed CBN grains are controlled effectively. In this case the compressive strength of the brazed grains reaches 15.3 N, which is as high as that of the original ones. Copyright © 2009 John Wiley & Sons, Ltd.