bluuebunny/crossref_metadata_2025_split huggingface dataset:
The maleimide modified epoxy resins for the preparation of UV‐curable hybrid coatings
Authors: Altıntaş Zerrin , Karataş Sevim , Kayaman‐Apohan Nilhan , Güngör Atilla 
Published: September 2009

AbstractIn the present study, maleimide‐modified epoxide resin containing UV‐curable hybrid coating materials were prepared and coated on polycarbonate substrates in order to improve their surface properties. UV‐curable, bismaleimide‐modified aliphatic epoxy resin was prepared from N‐(p‐carboxyphenyl) maleimide (p‐CPMI) and cycloaliphatic epoxy (Cyracure‐6107) resin. The structure of the bismaleimide modified aliphatic epoxy resin was analyzed by FTIR and the characteristic absorption band for maleimide ring was clearly observed at 3100 cm−1. Silica sol was prepared from tetraethylorthosilicate (TEOS) and methacryloxy propyl trimethoxysilane (MAPTMS) by sol–gel method. The coating formulations with different compositions were prepared from UV‐curable bismaleimide‐based epoxy oligomer and sol–gel mixture. The molecular structure of the hybrid coating material was analyzed by 29Si‐CP/MAS NMR spectroscopy techniques. In the 29Si CP/MAS NMR spectrum of the hybrid coating, mainly two kinds of signals were observed at −68 and −110 ppm that correspond to T3 and Q4 peaks, respectively. This result shows that a fully condensed structure was obtained. The thermal and morphological properties of these coatings materials were investigated by using TGA and SEM techniques. Hardness and abrasion resistance properties of coating materials were examined and both were found to increase with sol–gel precursor content of the coating. The photopolymerization kinetics was investigated by using RT‐IR. 70% conversion was attained with the addition of 15 wt% of BMI resin into the acrylate‐based coating formulation. It was found that the UV‐curable organic–inorganic hybrid coatings improved the surface properties of polycarbonate. Copyright © 2009 John Wiley & Sons, Ltd.
Efficient polymers in conjunction with membranes to remove As(V) generated in situ by electrocatalytic oxidation
Authors: Rivas Bernabé L. , Aguirre María del Carmen , Pereira Eduardo , Bucher Christophe , Moutet Jean‐Claude , Aman Eric Saint , Royal Guy 
Published: September 2009

AbstractElectrochemistry and ultrafiltration membrane methods (electro‐oxidation and liquid phase polymer based retention technique LPR, respectively) were coupled to remove As(III) inorganic species from aqueous solutions. Our main objective was to achieve an efficient extraction of arsenic species by associating a polymer‐assisted liquid phase retention procedure, based on the As(V) adsorption properties of cationic water‐soluble polymers, with the electrocatalytic oxidation process of As(III) into its more easily removable analog As(V). The exhaustive oxidation of As(III)–As(V) was readily performed in high yield at iridium oxide film modified carbon felt electrodes in the presence of different water‐soluble poly(quaternary ammonium) salts acting also as supporting electrolyte. The progress of the macro‐scale oxidation of As(III)–As(V) was followed using iridium oxide film modified glassy carbon electrodes. Finally, a study on arsenic retention by LPR‐technique performed on fully oxidized solutions of arsenic, showing that complete (100%) retention of the arsenic could be achieved using a 20:1 polyammonium:As(III) mole ratio. Copyright © 2009 John Wiley & Sons, Ltd.
Thermally conductive boron nitride/SEBS/EVA ternary composites: “Processing and characterization”
Authors: Kemaloglu Sebnem , Ozkoc Guralp , Aytac Ayse 
Published: September 2009

AbstractThe aim of this study is to investigate the effect of hexagonal boron nitride (BN) particle shape/size and loading level on the thermal, mechanical, electrical properties, and morphology of styrene‐ethylene‐butylene‐styrene terpolymer (SEBS)/poly(ethylene‐co‐vinyl acetate) (EVA) blends to be used as thermal interface materials (TIM). It is observed from the scanning electron microscopy (SEM) of BN powders that each type has a characteristic particle size distribution and particle shape. SEM analysis conducted on matrices (i.e. SEBS/EVA blends) does not indicate any sign of interfacial delamination or phase separation between components. The surface energy measurements and subsequent wettability coefficient calculations point out that the dispersion of BN in SEBS is thermodynamically more favorable than that of BN in EVA. In other words, SEBS tends to encapsulate BN particles in comparison to EVA. Thermal conductivity of composites increases with increasing filler loading level regardless of filler size and shape. It is found that the composites with smaller BN particles (i.e. high aspect ratio and plate‐like particles) shows higher thermal conductivity than that of the composites with larger particles at the same filler content. The tensile strength of the composites reduces with the incorporation of BN regardless of BN content and matrix composition. The increasing content of BN in the matrix gradually improves the moduli of the composites. The hardness of composites enhances with BN loading level and SEBS/EVA ratio regardless of filler type. The increasing amount of EVA in the composites results in a decrease in dielectric constant of neat matrices and composites. POLYM. COMPOS., 31:1398–1408, 2010. © 2009 Society of Plastics Engineers
Substituent effects on conformational preference in α‐substituted α‐fluorophenylacetic acid methyl ester model systems for chiral derivatizing agents
Authors: Sahnoun Riadh , Fujimura Yuichi , Kabuto Kuninobu , Takeuchi Yoshio , Noyori Ryoji 
Published: September 2009

AbstractIn connection with study of chiral derivatizing agents (CDAs) for NMR determination of absolute configuration of organic compounds, factors controlling the conformational preference between syn‐ and anti‐forms in α‐substituted α‐fluorophenylacetic acid methyl ester (FC(X)(Ph)COOMe) model systems were theoretically investigated. Substituents X at the stereogenic carbon atom were X = H, CCH and CH3, the electronic and steric properties of which were significantly different from each other. The model system with X = CCH and that with X = CH3 were found to be possible candidates for fluorine‐containing CDAs. The syn conformation is stable compared with the anti one by 0.7 kcal mol−1 for the ester with X = CCH. On the other hand, the anti conformation is stable compared with the syn one by 0.5 kcal mol−1 for the ester with X = CH3. Both natural bond orbital (NBO) analysis and deletion of selected orbitals based on the donor–acceptor NBO scheme were adopted for semi‐quantitative estimation of factors responsible for the conformational preference as well as a qualitative inspection of occupied canonical molecular orbitals (MOs). It was shown that [σ–(σ* + π*)(CO)] and [σ–σ*(Ph) and π(Ph)–σ*] hyperconjugations are the main factors controlling the conformational preferences between the syn and anti conformations. Other types of effects such as electrostatic effects were also investigated. The role of the fluorine atom was also clarified. Copyright © 2009 John Wiley & Sons, Ltd.
Naphthalene‐based poly(arylene ether ketone) copolymers containing sulfobutyl pendant groups for proton exchange membranes
Authors: Shao Ke , Zhu Jing , Zhao Chengji , Li Xianfeng , Cui Zhiming , Zhang Yang , Li Hongtao , Xu Dan , Zhang Gang , Fu Tiezhu , Wu Jing , Na Hui , Xing Wei 
Published: September 2009

AbstractA new monomer 1,5‐bis(4‐fluorobenzoyl)‐2,6‐dimethoxynaphthalene (DMNF) was prepared and further polymerized to form naphthalene‐based poly(arylene ether ketone) copolymers containing methoxy groups (MNPAEKs). The side‐chain‐type sulfonated naphthalene‐based poly(arylene ether ketone) copolymers (SNPAEKs) were obtained by demethylation and sulfobutylation. Flexible and tough membranes with reasonably high mechanical strength were prepared. The SNPAEKs membrane showed anisotropic membrane swelling with larger swelling in thickness than in plane. Transmission electron microscopy (TEM) analysis revealed clear nanophase separated structure of SNPAEKs membranes, which composed of hydrophilic side chain and hydrophobic main‐chain domains. Proton conductivities of copolymers increased gradually with increase in temperature. The highest conductivity of 0.179 S/cm was obtained for SNPAEK‐80 (IEC = 1.82 mequiv/g) at 80 °C, which is higher than that of Nafion117 (0.146 S/cm). The SNPAEKs membranes exhibit the methanol permeability in the range of 3.42 × 10−8−4.49 × 10−7 cm2/s, which are much lower than that of Nafion117. They could be the promising materials as alternative to Nafion membrane for direct methanol fuel cells applications. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47:5772–5783, 2009
The Influence of Surface Treatment on Photocatalytic Activity of PE CVD TiO2 Thin Films
Authors: Hajkova Pavlina , Spatenka Petr , Krumeich Joerg , Exnar Petr , Kolouch Ales , Matousek Jindrich 
Published: September 2009

AbstractThe aim of this paper is investigation of the photocatalytic properties of TiO2 thin films prepared by PECVD with metal nanoparticles built‐up on the film surface. The deposition of TiO2 films was carried out in the radio frequency (RF) low‐pressure PECVD reactor. Layers were deposited at two different substrate temperatures (40 and 300 °C). The surface of TiO2 films was subsequently covered by noble metal nanoparticles—silver, platinum, and gold, deposited by different methods. For determination of the photocatalytic decomposition the Acid orange 7 (AO7) C16H11N2NaO4S organic dye was used. Selected samples were used for antibacterial tests (Gram‐negative bacteria Escherichia coli). The results clearly proved that presence of metal clusters resulted in enhancement of the photocatalytic and antibacterial activity.
Thin Protective Aluminum Layer on Mg‐Li Alloy by Plasma Spraying and Cold Rolling
Authors: Oki Sachio , Tsujikawa Masato , Morishige Taiki , Kamita Masaichiro 
Published: September 2009

AbstractFormation of a protective thin surface of pure aluminum on Mg‐14mass%Li alloy by plasma thermal spraying and the cold rolling was investigated. An Mg‐14mass%Li‐1mass%Al alloy ingot was melted and cast in a pressurized argon atmosphere. After homogeneous heat treatment, the ingot was rolled to 3 mm‐thick plate with a reduction ratio of 98%. The plate specimens were annealed again. Plasma sprayings of pure aluminum were carried out with various conditions after grit blasting. The coated layer thickness was about 100 µm. There was slight increase in temperature during spraying on substrates. The first pass of rolling was carried out at 250 °C; then several cold rolling passes were processed to reduce the entire thickness up to 90% in reduction ratio of the sprayed specimens' thickness. It was found that the determining factor for sound rolled sheet without separation of aluminum coating was the maximum temperature of the substrate at plasma processing. There were no separation, for specimen heated in the temperature range between 300 and 400 °C during thermal spraying, at rolling up to 90% in total reduction ratio. Sectional observation revealed a continuous thin aluminum layer adhered on the Mg‐14mass%Li alloy.
Changes in the urinary proteome post‐operatively in renal cancer patients – a reflection of tumour or kidney removal?
Authors: Sim Sheryl H. , Cairns David A. , Perkins David N. , Peng Jianhe , Stanley Anthea J. , Thompson Douglas , Lewington Andrew , Selby Peter J. , Banks Rosamonde E. 
Published: September 2009

AbstractDuring the initial phases of a study focussed on discovering new urinary biomarkers for renal cell carcinoma, a number of challenges and limitations were identified, which we subsequently investigated. The purpose of this report is to provide insight into experimental design for such investigations and potential confounding factors that can impact on such studies. Sixty urine samples from 20 patients with clear cell renal cell carcinoma and ten live renal transplant donor patients, pre‐ and post‐nephrectomy, were profiled using SELDI‐TOF‐MS incorporating stringent quality control and in‐house data processing/analysis. There were 65 significantly differentially expressed peaks (five solitary peaks and four peak clusters that increased post nephrectomy and four peak clusters that decreased). Peak 3934 Da m/z and peaks within 11731–11961 Da m/z, which increased post nephrectomy were identified as the 36 amino acid isoform of β‐defensin‐1 and β2‐microglobulin, respectively. However, changes in these two protein forms were also seen in healthy donors following nephrectomy implying a relationship with kidney removal per se rather than tumour removal. This study indicates the difficulties in identifying SELDI peaks for subsequent validation and illustrates the need for appropriate controls in biomarker studies to determine whether changes are indirect consequences of treatment.
Characterization of a novel novobiocin analogue as a putative C‐terminal inhibitor of heat shock protein 90 in prostate cancer cells
Authors: Matthews Shawna B. , Vielhauer George A. , Manthe Craig A. , Chaguturu Vamsee K. , Szabla Kristen , Matts Robert L. , Donnelly Alison C. , Blagg Brian S. J. , Holzbeierlein Jeffrey M. 
Published: September 2009

AbstractPURPOSEHsp90 is important in the folding, maturation and stabilization of pro‐tumorigenic client proteins and represents a viable drug target for the design of chemotherapies. Previously, we reported the development of novobiocin analogues designed to inhibit the C‐terminal portion of Hsp90, which demonstrated the ability to decrease client protein expression. We now report the characterization of the novel novobiocin analogue, F‐4, which demonstrates improved cytotoxicity in prostate cancer cell lines compared to the N‐terminal inhibitor, 17‐AAG.MATERIALS AND METHODSLNCaP and PC‐3 cells were treated with 17‐AAG or F‐4 in anti‐proliferative, apoptosis, cell cycle and cytotoxicity assays. Western blot and prostate specific antigen (PSA) ELISAs were used to determine client protein degradation, induction of Hsp90 and to assess the functional status of the androgen receptor (AR) in response to F‐4 treatment. Surface plasmon resonance (SPR) was also used to determine the binding properties of F‐4 to Hsp90.RESULTSF‐4 demonstrated improved potency and efficacy compared to novobiocin in anti‐proliferative assays and decreased expression of client proteins. PSA secretion was inhibited in a dose‐dependent manner that paralleled a decrease in AR expression. The binding of F‐4 to Hsp90 was determined to be saturable with a binding affinity (Kd) of 100 µM. In addition, superior efficacy was demonstrated by F‐4 compared to 17‐AAG in experiments measuring cytotoxicity and apoptosis.CONCLUSIONSThese data reveal distinct modes of action for N‐terminal and C‐terminal Hsp90 inhibitors, which may offer unique therapeutic benefits for the treatment of prostate cancer. Prostate 70: 27–36, 2010. © 2009 Wiley‐Liss, Inc.
Long term increased expression of the short form 1b prolactin receptor in PC‐3 human prostate cancer cells decreases cell growth and migration, and causes multiple changes in gene expression consistent with reduced invasive capacity
Authors: Huang Kuang‐tzu , Walker Ameae M. 
Published: September 2009

AbstractBACKGROUNDWe have shown that treatment of human prostate cancer cells with the selective prolactin (PRL) receptor modulator, S179D PRL, inhibits growth in vitro, and the initiation and growth of xenografts in vivo. S179D PRL treatment also upregulates expression of the short form 1b (SF1b) PRL receptor, activation of which upregulates expression of the cell cycle‐regulating protein, p21.METHODSWe examined the consequences of long term increased expression and activation of SF1b, at levels comparable to those resulting from treatment with S179D PRL, by creating PC‐3‐derived stable cell lines expressing a constitutively active form of SF1b, ΔS2 SF1b.RESULTSIncreased expression of ΔS2 SF1b decreased growth and migration of the cells. This was accompanied by an increase in cell‐matrix interactions, and cell–cell aggregation when cells were plated on basement membrane components. Real‐time PCR evaluated the expression of genes related to invasive capacity. Of particular interest was decreased expression of the protease, urokinase‐type plaminogen activator, and its receptor, uPAR, and increased expression of its inhibitors, PAI‐1 and 2. Also decreased in cells with increased expression of ΔS2 SF1b was expression of basic fibroblast growth factor and vascular endothelial growth factor.CONCLUSIONWe conclude that at least part of the beneficial effects of S179D PRL is the result of increased expression of SF1b, and that the effects of increased expression and activation of SF1b continue to be of potential benefit in the long term. Prostate 70: 37–47, 2010. © 2009 Wiley‐Liss, Inc.
Global levels of histone modifications predict prostate cancer recurrence
Authors: Ellinger Jörg , Kahl Philip , von der Gathen Johannes , Rogenhofer Sebastian , Heukamp Lukas C. , Gütgemann Ines , Walter Bernhard , Hofstädter Ferdinand , Büttner Reinhard , Müller Stefan C. , Bastian Patrick J. , von Ruecker Alexander 
Published: September 2009

AbstractPURPOSEEpigenetic alterations such as DNA methylation and histone modifications play important roles in carcinogenesis. It was reported that global histone modification patterns are predictors of cancer recurrence in various tumor entities. Our study was performed to evaluate histone lysine (HxKy) and histone acetyl (HxAc) modifications in prostate tissue.MATERIALS AND METHODSA tissue microarray with 113 prostate cancer (PCA), 23 non‐malignant prostate tissues was stained with antibodies against H3K4 mono‐(H3K4me1), di‐(H3K4me2), tri‐(H3K4me3) methylation, H3K9me1, H3K9me2, H3K9me3, H3 and H4 pan‐acetylation (H3Ac, H4Ac). We also analyzed H3K4 methylation in patients with advanced PCA (hormone‐refractory PCA—HRPC, n = 34; hormone‐dependent PCA, n = 30). Sections were scored according the staining intensity and the proportion of epithelial cells showing nuclear staining.RESULTSH3K4me1, H3K9me2, H3K9me3, H3Ac, and H4Ac were significantly reduced in PCA compared to non‐malignant prostate tissue. H3Ac and H3K9me2 levels allowed discrimination of PCA and non‐malignant prostate tissue highly specifically (>91%) and sensitively (>78%) as determined via ROC analyses (AUC >0.91). Histone lysine methylation and histone acetylation marks were correlated with clinical–pathological parameters (i.e., digital rectal examination, preoperative PSA, pT‐stage, lymph node metastasis, Gleason score). In addition, H3K4me1 was a significant predictor of PSA recurrence following radical prostatectomy. H3K4me1, H3K4me2, and H3K4me3 levels were significantly increased in HRPC.CONCLUSIONSGlobal histone modification levels may help to identify patients with adverse prognosis, and represent a target for the future therapy of PCA. Prostate 70: 61–69, 2010. © 2009 Wiley‐Liss, Inc.
PSA and body composition by dual X‐Ray absorptiometry (DXA) in NHANES
Authors: Fowke Jay H. , Matthews Charles E. 
Published: September 2009

AbstractBACKGROUNDObese men are at higher risk for advanced prostate cancer and have a poorer prognosis following treatment. Several studies also report that obese men have lower blood PSA levels, suggesting that obesity may be interfering with the ability to detect early‐stage prostate cancer.METHODSDual X‐ray absorptiometry (DXA) is considered a gold‐standard measurement of body composition. We investigated the association between PSA levels and body composition measured by DXA among 1,360 men participating in NHANES (2001–2004), a representative sample of the U.S. male population.RESULTSAfter controlling for age, race, and other factors, PSA concentration was ∼15% lower for men with the highest level of total mass, lean mass, fat mass, trunk lean mass, and trunk fat mass (all P for trend <0.05). We then multiplied PSA concentration by estimated plasma volume to calculate the amount of PSA in circulation (i.e., PSA mass). Total body fat mass and fat mass located in the body trunk were not significantly associated with PSA mass, however, PSA mass was ∼10–15% higher across low versus high categories of total body lean mass and bone mineral content (all P‐trend <0.05).CONCLUSIONOur results using DXA to measure body composition confirm that a greater body mass, not just fat mass, is associated with a lower PSA concentration. This is consistent with PSA hemodilution within men with a higher body mass index. The separate associations between measured lean and fat mass on calculated PSA mass require further investigation. Prostate 70: 120–125, 2010. ©2009 Wiley‐Liss, Inc.
Modifying the conserved C‐terminal tyrosine of the peptide hormone PYY3‐36 to improve Y2 receptor selectivity
Authors: Pedersen Søren L. , Holst Birgitte , Vrang Niels , Jensen Knud J. 
Published: September 2009

AbstractThe Y2 selective PYY derived peptide PYY3‐36 was recently shown to play a role in appetite regulation. Novel PYY3‐36 analogs with high selectivity for the Y2 receptor could be potential drug candidates for the treatment of obesity. The C‐terminal pentapeptide segment of PYY3‐36 is believed to bind to the Y receptors. Tyr‐36 is highly conserved across species and only few successful modifications of Tyr‐36 have been documented. PYY3‐36 analogs were prepared using solid‐phase peptide chemistry and tested for binding to the Y1, Y2 and Y4 receptor subtypes by radioligand displacement assay. The Y2 receptor agonists with the best affinity and selectivity were further investigated for activity towards the Y1 and Y2 receptor subtypes. Unexpectedly, modifications of Tyr‐36 were well‐tolerated, and the analogs of PYY3‐36 in which the Tyr‐36 hydroxyl group was substituted with a halogen or an amino group were particularly well tolerated and yielded an improved selectivity and approximately equipotent affinity to the Y2 receptor. These modifications could be used to design new potential drug candidates for the treatment of obesity. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Incorporation of N‐amidino‐pyroglutamic acid into peptides using intramolecular cyclization of α‐guanidinoglutaric acid
Authors: Burov Sergey , Moskalenko Yulia , Dorosh Marina , Shkarubskaya Zoya , Panarin Evgeny 
Published: September 2009

AbstractN‐terminal modification of peptides by unnatural amino acids significantly affects their enzymatic stability, conformational properties and biological activity. Application of N‐amidino‐amino acids, positively charged under physiological conditions, can change peptide conformation and its affinity to the corresponding receptor. In this article, we describe synthesis of short peptides, containing a new building block—N‐amidino‐pyroglutamic acid. Although direct guanidinylation of pyroglutamic acid and oxidation of N‐amidino‐proline using RuO4 did not produce positive results, N‐amidino‐Glp‐Phe‐OH was synthesized on Wang polymer by cyclization of α‐guanidinoglutaric acid residue. In the course of synthesis, it was found that literature procedure of selective Boc deprotection using TMSOTf/TEA reagent is accompanied by concomitant side reaction of triethylamine alkylation by polymer linker fragment. It should be mentioned that independently from cyclization time and coupling agent (DIC or HCTU), the lactam formation was incomplete. Separation of the cyclic product from the linear precursor was achieved by HPLC in ammonium formate buffer at pH 6. HPLC analysis showed N‐amidino‐Glp‐Phe‐OH stability at acidic and physiological pH and fast ring opening in water solution at pH 9. The suggested method of N‐amidino‐Glp residue formation can be applied in the case of short peptide chains, whereas synthesis of longer ones will require fragment condensation approach. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.