bluuebunny/crossref_metadata_2025_split huggingface dataset:
Proteomic analysis of chromium cytotoxicity in cultured rat lung epithelial cells
Authors: Lei Ting , He Qing‐Yu , Cai Zhen , Zhou Yuan , Wang Yi‐Li , Si Lu‐Sheng , Cai Zongwei , Chiu Jen‐Fu 
Published: June 2008

AbstractChromium (Cr) has been widely used in industry for more than one century. Exposure to hexavalent Cr compounds is strongly associated with increasing risk of lung cancer. Extensive researches at DNA level indicated that generation of ROS from the reduction of Cr(VI) leading to DNA damage is the major cause of the toxicity and carcinogenicity of Cr(VI). The present study in cellular and protein levels confirmed that Cr(VI) induced apoptosis of lung epithelial cells (LEC) via ROS generation. To view the differentially expressed proteins in the process of Cr(VI) reduction, subcellular proteomics was applied and allowed the identification of more than 30 proteins with expression alteration. Most of those proteins are correlated with ROS‐elicited responses, which were further validated by Western blotting analysis, induction of p53 pathway and antioxidative treatment. The current findings provided additional evidence in protein level to support the claim that ROS generated during the process of Cr(VI) reduction are involved in the Cr(VI)‐induced toxicity and carcinogenesis.
Effect of protein degradation on spot Mr distribution in 2‐D gels – a case study of proteolysis during development of Streptomyces coelicolor cultures
Authors: Vohradsky Jiri , Branny Pavel , Li Xin‐Ming , Thompson Charles J. 
Published: June 2008

AbstractProteolysis, a regulated biological process, is reflected by protein spot molecular weight distribution in 2‐D gel electrophoretograms. Here we report studies of Streptomyces cultures as they undergo two different developmental processes involving proteolysis. Systematic changes in protein molecular weight distribution between the control samples and those with high activity of proteases were demonstrated. The observations were supported by a numerical model of degradation and its influence on the Mr distribution. Simple statistics could be used to distinguish between normal and degradative 2‐D gel electrophoretic patterns.
Quantitative changes in protein expression of cadmium‐exposed poplar plants
Authors: Kieffer Pol , Dommes Jacques , Hoffmann Lucien , Hausman Jean‐François , Renaut Jenny 
Published: June 2008

AbstractCadmium (Cd) pollution is a worldwide major concern having, among others, deleterious effects on plants. In the present work, the effects of a 20 μM Cd exposure in hydroponics culture during 14 days were evaluated in young poplar leaves. Proteins were analysed by 2‐D DIGE, followed by MALDI‐TOF‐TOF identification. Additionally, growth and other physiological parameters were monitored during the experiment. Treated plants exhibited an inhibition of growth and visual symptoms appeared after 7 days. A significant accumulation of Cd in all organs was recorded by ICP‐MS analysis. A number of changes in the expression of proteins with various functions were identified; in particular a decreased abundance of oxidative stress regulating proteins, whereas pathogenesis‐related proteins showed a drastic increase in abundance. Furthermore, a large number of proteins involved in carbon metabolism showed a decrease in abundance, while proteins involved in remobilizing carbon from other energy sources were upregulated. In conclusion, the negative effect of Cd could be explained by a deleterious effect on protein expression from the primary carbon metabolism and from the oxidative stress response mechanism. Accumulation of Cd in stems of poplar, coupled with a low impact of Cd on physiological parameters, promotes the use of poplar trees for phytoremediation purposes.
OMSSAGUI: An open‐source user interface component to configure and run the OMSSA search engine
Authors: Tharakan Ravi , Martens Lennart , Van Eyk Jennifer E. , Graham David R. 
Published: June 2008

AbstractWe here present a user‐friendly and extremely lightweight tool that can serve as a stand‐alone front‐end for the Open MS Search Algorithm (OMSSA) search engine, or that can directly be used as part of an informatics processing pipeline for MS driven proteomics. The OMSSA graphical user interface (OMSSAGUI) tool is written in Java, and is supported on Windows, Linux, and OSX platforms. It is an open source under the Apache 2 license and can be downloaded from http://code.google.com/p/mass‐spec‐gui/.
Effect of duration of ischemia on myocardial proteome in ischemia/reperfusion injury
Authors: Fert‐Bober Justyna , Basran Rasphal S. , Sawicka Jolanta , Sawicki Grzegorz 
Published: June 2008

AbstractIschemia/reperfusion (I/R) injury is a serious problem resulting from clinical setting of coronary revascularization. Despite extensive studies on I/R injury, the molecular bases of cardiac dysfunction caused by I/R are still unknown, but are likely to result from alterations in protein expression. Isolated rat hearts were subjected to 15–30 min of no‐flow ischemia without (Ischemia protocol) or with 30 min of reperfusion (I/R protocol). 2‐DE analysis of heart proteins from both experimental protocols showed wide‐ranging changes in protein levels. In the Ischemia protocol, 39 protein spots were changed in ischemic groups and those changes correlated with duration of ischemia. Ninety percent of the affected proteins were increased. In contrast to increased protein levels, the total messenger RNA (mRNA) level decreased approximately two fold. Compared to the Ischemia protocol, changes in protein levels in the I/R protocol did not correlate with the duration of ischemia and the degree of recovery of mechanical function. The decrease of affected protein from I/R protocol was associated with the increase in total protein level in reperfusate. Our studies show that the protein increase is correlated with the mechanical function of the I/R hearts and the increase is not likely associated with an increase in protein synthesis.
Discrimination between stable and dynamic components of protein complexes by means of quantitative proteomics
Authors: Kito Keiji , Kawaguchi Noriko , Okada Satoshi , Ito Takashi 
Published: June 2008

AbstractTo discriminate between stable and dynamic protein–protein interactions, we propose a strategy in which cells with and without tagged bait are differentially labeled with stable isotope and combined prior to complex purification. Mass‐spectrometric analysis of the purified complexes identifies stable and dynamic components as those derived exclusively from the tagged cells and those from both cells, respectively. We successfully applied this strategy to analyze two yeast protein complexes, eIF2B–eIF2 and cyclin–Cdc28.
Synthesis and magnetic properties of comb‐like copolymeric complexes based on thiazole ring and ionic liquid
Authors: Yang Jun , Sun Weilin , Lin Weihong , Shen Zhiquan 
Published: June 2008

AbstractTwo comb‐like copolymers (BIMT and PMB) composed of N‐2‐thiazolylmethacrylamide (NTMA) and 2‐(1‐butylimidazolium‐3‐yl) ethyl methacrylate tetrafluoroborate (BIMA) were prepared by free radical polymerization and reversible addition‐fragmentation chain transfer (RAFT) polymerization. The conversion of the monomers to copolymer has been confirmed by FTIR spectra and 1H NMR spectra. The metal (Ni2+, Nd3+) complexes of these two copolymers were prepared, and the magnetic behaviors of the complexes were studied. The coordinated complexes display three possible chelating structures, which lie on the nitrogen donor and oxygen donor ligands and the kinds of the metal ions. The bimetallic complexes (BIMT‐Nd‐Ni and PMB‐Nd‐Ni) were synthesized by using the different coordination sites of the polymers. The magnetic properties of the complexes show that different structures arising from the different preparations, the kinds and the contents of metal ions, and the state of the complexes can infect the exchange interaction between the metal ions and induce various magnetic phenomena. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5123–5132, 2008
Polymerization of norbornene with a pendent sulfonyl fluoride group catalyzed by palladium complex bearing tBu3P ligand
Authors: Takamiya Ikuko , Yamashita Makoto , Murotani Eisuke , Morizawa Yoshitomi , Nozaki Kyoko 
Published: June 2008

AbstractThe combination of palladium complex (tBu3P)Pd(Me)Cl (1) and NaB[3,5‐(CF3)2C6H3]4 (NaBAr4) catalyzed homopolymerization of a novel monomer, norbornene (NB) with a pendent 2‐fluorosulfonyltetrafluoroethoxymethyl chain (NBSF). Catalytic activities of 1/NaBAr4 were higher than those of previously reported palladium or nickel catalysts, probably, because the palladium center with electron donative tBu3P ligand was barely poisoned by the sulfonyl fluoride coordination. Thus, 1/NaBAr4 is the current best catalyst system for NBSF polymerization. The catalyst system also gave copolymers of NB with NBSF. The obtained copolymers have high sulfonyl‐fluoride incorporation and a narrow molecular weight distribution. Present catalyst system could control incorporation ratio of NBSF by changing a feed monomer ratio with slow addition of NB solution. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5133–5141, 2008
On the anionic homo‐ and copolymerization of ethyl‐ and butyl‐2‐cyanoacrylates
Authors: Denchev Zlatan , Tomanova Milena , Lederer Albena 
Published: June 2008

AbstractEthyl‐(ECA) and butyl‐2‐cyanoacrylate (BCA) monomers of high purity and acidic stabilization were synthesized and anionically polymerized to homo‐ and copolymers in two different ways: by piperidine‐catalyzed bulk polymerization leading to transparent, brittle films (method A) and by polymerization in aqueous medium in the presence of sodium bicarbonate to obtain white powders (Method B). The molecular structure of the synthesized monomers, homopolymers and copolymers were corroborated by spectral methods. The polymers were studied further by thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), size exclusion chromatography (SEC) and proton nuclear magnetic resonance (1H NMR). Controlling the composition of the monomer feed and the way the polymerization was performed, it was possible to obtain phase separated or homogeneous cyanoacrylate copolymers with glass transitions varying between the Tg of polyECA and that of polyBCA. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5142–5156, 2008
Polyesters analogous to PET and PBT based on O‐benzyl ethers of xylitol and L‐arabinitol
Authors: Zamora Francisca , Hakkou Khalid , Alla Abdelilah , Marín‐bernabé Romina , de Paz María V. , Martínez de Ilarduya Antxon , Muñoz‐guerra Sebastián , Galbis Juan A. 
Published: June 2008

AbstractThe synthesis, characterization, and some properties of new copolyesters of poly(butylene terephthalate) (PBT) and poly(ethylene terephthalate) (PET) based on L‐arabinitol and xylitol are described. These copolyesters were obtained by polycondensation reaction in the melt of mixtures of 1,4‐butanediol or ethylene glycol and 2,3,4‐tri‐O‐benzyl‐L‐arabinitol or 2,3,4‐tri‐O‐benzyl‐xylitol with dimethyl terephthalate. Their weight‐average molecular weights ranged between 7000 and 55,000, with polydispersities ranging from 1.4 to 4.7. Copolymers containing 1,4‐butanediol could be analyzed by NMR, and were found to have a statistical microstructure. All these copolyesters were thermally stable, with degradation temperatures well above 300 °C. With increasing amounts of alditol in the copolyester, the melting temperature and crystallinity decreased in both series, and the glass transition temperature increased for the PBT series and decreased for the PET series. Only PBT‐derived copolyesters containing a maximum of 10% alditol units showed discrete scattering characteristic of crystalline material. No substantial differences in either structure or properties were observed between the L‐arabinitol and xylitol copolyester series. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5167–5179, 2008
Host copolymers containing pendant carbazole and oxadiazole groups: Synthesis, characterization and optoelectronic applications for efficient green phosphorescent OLEDs
Authors: Yeh Kun‐Ming , Lee Chih‐Cheng , Chen Yun 
Published: June 2008

AbstractVinyl copolymers (PCOn), containing pendant carbazole and aromatic 1,3,4‐oxadiazole attached with dodecyloxy group, were prepared from their corresponding precursor poly(9‐vinyl carbazole‐co‐4‐vinylbenzyl chloride) (PCBn) by the Williamson condensation (n: mole% of 4‐vinylbenzyl chloride). These copolymers were used as host materials for green phosphorescent light‐emitting diodes after blending 4 wt % of Ir(ppy)3. PL spectra of the PCOn films showed the formation of excimer or exciplex. The phosphorescent EL devices were fabricated with a configuration of ITO/PEDOT:PSS/host copolymers:Ir(ppy)3/BCP/Ca/Al. The PL and EL spectra of the blends [PCOn:Ir(ppy)3] revealed dominant green emission at 517 nm attributed to Ir(ppy)3 due to efficient energy transfer from the host to Ir(ppy)3. Efficient green phosphorescent OLEDs was obtained when employing copolymer PCO16 as the host and Ir(ppy)3 as the guest. The maximal luminance efficiency and the maximal luminance of this device were 17.9 cd/A and 19,903 cd/m2, respectively. After doped with Ir(ppy)3, the morphology of the films, both controlled PCO20 and PCO20 with attached dodecyloxy groups, were investigated by tapping‐mode AFM and FE‐SEM. The film of PCO20 exhibited uniform, featureless image and showed much better device performance than PCO20, which have been attributed to good compatibility of PCO20 with Ir(ppy)3. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5180–5193, 2008
Cationic photopolymerization of liquid fullerene derivative under visible light
Authors: Lintinen Kalle , Efimov Alexander , Hietala Sami , Nagao Shijo , Jalkanen Pasi , Tkachenko Nikolai , Lemmetyinen Helge 
Published: June 2008

AbstractWe describe the synthesis and cationic photopolymerization of a C60 derivative bearing a 2,4,6‐tris(epoxynonyloxy)phenyl moiety (FB9ox). Rheological analysis of monomer indicates that temperature of 130 °C yields sufficiently low viscosity for polymerization. A thin film of the liquid monomer has been cationically photopolymerized with a photoinitiator system of curcumin and p‐(octyloxyphenyl)phenyliodonium hexafluoroantimonate, which harvests 424 nm light instead of commonly used ultraviolet light. The degree of polymerization was determined with ATR‐IR. The reaction is the first recorded photopolymerization of a fullerene derivative thin film. The polymer exhibits good mechanical and chemical stabilities. The polymerization can also be achieved by annealing at 150 °C without illumination, but with a smaller degree of polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5194–5201, 2008
Ring‐opening polymerization of 1,4‐dioxan‐2‐one initiated by lanthanum isopropoxide in bulk
Authors: Zhu Xiao‐Lan , Wu Gang , Qiu Zhi‐Cheng , Zhou Yan , Gong Jie , Yang Ke‐Ke , Wang Yu‐Zhong 
Published: June 2008

AbstractLanthanum isopropoxide (La(OiPr)3) has been synthesized and employed for ring‐opening polymerization of 1,4‐dioxan‐2‐one in bulk as a single‐component initiator. The influences of reaction conditions such as initiator concentration, reaction time, and reaction temperature on the polymerization were investigated. The kinetics indicated that the polymerization is first‐order with respect to the monomer concentration. The Mechanistic investigations according to 1H NMR spectrum analysis demonstrated that the polymerization of PDO proceeded through a coordination‐insertion mechanism with a rupture of the acyl‐oxygen bond of the monomer rather than the alkyl‐oxygen bond cleavage. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5214–5222, 2008
Synthesis of soluble poly(para‐phenylene) with a long polymer chain: Characteristics of regioregular poly(1,4‐phenylene)
Authors: Natori Itaru , Natori Shizue , Sekikawa Hiroyuki , Sato Hisaya 
Published: June 2008

AbstractSoluble poly(para‐phenylene) having a long polymer chain (more than six repeat units) was synthesized with a tert‐butyl end‐group (t‐PPP) and was found to have improved solubility and excellent optical properties. Poly(1,3‐cyclohexadiene) (PCHD) consisting of only 1,4‐cyclohexadiene (1,4‐CHD) units was synthesized with a tert‐butyl end‐group (t‐PCHD), and completely dehydrogenated to obtain t‐PPP. This end‐group effectively prevented the crystallization of t‐PPP, and polymers containing up to 16 repeat units were soluble in tetrahydrofuran. Soluble t‐PPP obtained had an ability to form a tough thin film prepared by spin‐coating method. Optical analyses of t‐PPP provided strong evidence for a linear polymer chain structure. A block copolymer of t‐PPP and a soluble polyphenylene (PPH) was then synthesized, and the excellent optical properties were retained by this block copolymer along with its solubility. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5223–5231, 2008
Facile electrosyntheses of high tensile strength alkyl‐bridged dicarbazole polymer films and its fluorescence spectra
Authors: Wei Zhenhong , Wang Qin , Xu Jingkun , Nie Yanglong , Du Yukou , Xia Hongying 
Published: June 2008

AbstractHomogeneous and high‐quality free‐standing poly(1,6‐bis(carbazolyl) hexane) (P2Cz‐H) and poly(1,12‐bis(carbazolyl)dodecane) (P2Cz‐D) films were electrochemically synthesized in CH2Cl2 + 0.1 M tetrabutylammonium tetrafluoroborate solution. The electrochemical and physical properties indicated that the quality of P2Cz‐D film with tensile strength of 165 kg cm−2 was better than that of P2Cz‐H due to the flexible monomer 1,12‐bis(carbazolyl)dodecane (2Cz‐D) has a longer carbon chain than that of monomer 1,6‐bis(carbazolyl)hexane (2Cz‐H). On the other hand, both the dicarbazole monomers showed better polymer‐film‐forming capabilities than the single carbazole monomer, partly because of the special design of the polymer backbone constituted of stiff bicarbazyl chromophores linked by flexible long carbon segments. The structures of both dicarbazole polymers were investigated by UV–visible, infrared spectroscopy and scanning electron microscopy. Fluorescence spectral studies revealed that the two dedoped polymer films in solid state had strong emissions at ca. 411 and 415 nm. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5232–5241, 2008
A solution‐processible poly(p‐phenylene vinylene) without alkyl substitution: Introducing the cis‐vinylene segments in polymer chain for improved solubility, blue emission, and high efficiency
Authors: Wang Fangfang , He Feng , Xie Zengqi , Li Mao , Hanif Muddasir , Gu Xin , Yang Bing , Zhang Houyu , Lu Ping , Ma Yuguang 
Published: June 2008

AbstractA soluble all‐aromatic poly(2,5‐diphenyl‐1,4‐phenylenevinylene) (2,5‐DP‐PPV) is synthesized by utilizing aromatic phosphonium and aldehyde monomers through Wittig reaction. The H1 NMR and FTIR measurements indicate that over 50% content of cis‐vinylene units exist in polymer backbone. The diphenyl‐substituted benzaldehyde monomer plays an important role to enhance cis‐products (Z‐selectivity) in Wittig reactions. The twisted cis‐segments in polymer backbone reduce the interchain interactions and enhance the solubility of such all‐aromatic PPV derivative in common organic solvents. 2,5‐DP‐PPV exhibits good solubility in common organic solvents, such as tetrahydrofuran and chloroform. The polymer film exhibits a blue light emission (λmax = 485 nm) and a very high photoluminescence efficiency of 78%. The cis‐trans photo isomerization of this polymer in solution and the impact on the optical properties are also investigated. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5242–5250, 2008
Isoprene polymerization with indolide‐imine supported rare‐earth metal alkyl and amidinate complexes
Authors: Yang Yi , Wang Qiaoyi , Cui Dongmei 
Published: June 2008

AbstractReaction of 7‐{(N‐2,6‐R)iminomethyl)}indole (HL1, R = dimethylphenyl; HL2, R = diisopropylphenyl) and rare‐earth metal tris(alkyl)s, Ln(CH2SiMe3)3(THF)2, generated new rare‐earth metal bis(alkyl) complexes LLn(CH2SiMe3)2(THF) [L = L1: Ln = Lu (1a), Sc (1b); L = L2: Ln = Lu (3a), Sc (3b)] and mono(alkyl) complexes L22Lu(CH2SiMe3) (4a). Treatment of alkyl complexes 1a and 4a with N,N′‐diisopropylcarbodiimide afforded the corresponding amidinates L1Lu{iPr2NC(CH2SiMe3)NiPr2}2 (2a) and L22Lu{iPr2NC(CH2SiMe3)NiPr2} (5a), respectively. These new rare‐earth metal alkyls and amidinates except 4a in combination with aluminum alkyls and borate generated efficient homogeneous catalysts for the polymerization of isoprene, providing high cis‐1,4 selectivity and high molar mass polyisoprene with narrow molar mass distribution (Mn = 2.65 × 105, Mw/Mn = 1.07, cis‐1,4 98.2%, −60 °C). The environmental hindrance around central metals arising from the bulkiness of the ligands, the Lewis‐acidity of rare‐earth metal ions, the types of aluminum tris(alkyl)s and borate, and polymerization temperature influenced significantly on both the catalytic activity and the regioselectivity. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5251–5262, 2008
“Click” chemistry for in situ formation of thermoresponsive P(NIPAAm‐co‐HEMA)‐based hydrogels
Authors: Xu Xiao‐Ding , Chen Chang‐Sheng , Wang Zong‐Chun , Wang Gan‐Rui , Cheng Si‐Xue , Zhang Xian‐Zheng , Zhuo Ren‐Xi 
Published: June 2008

AbstractThe strategy for in situ chemical gelation of poly(N‐isopropylacrylamide‐co‐hydroxylethyl methacrylate) [P(NIPAAm‐co‐HEMA)]‐based polymers was demonstrated. Two types of new P(NIPAAm‐co‐HEMA) derivatives with alkyne and azide pendant groups, respectively, were prepared. When the solutions of the two derivatives were mixed together, a crosslinking reaction, a type of Huisgen's 1,3‐dipolar azide‐alkyne cycloaddition, in the presence of Cu(I) catalyst occurs. The morphology, equilibrium swelling ratio, swelling kinetics, and temperature response kinetics of the in situ gelated hydrogels were studied. In comparison with the conventional PNIPAAm hydrogel, because of the spatial hindrance of polymeric chains, the resulted hydrogels had a macroporous structure as well as a fast shrinking rate. The strategy described here presents a potential alternative to the traditional synthesis techniques for the in situ formation of thermoresponsive hydrogels. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5263–5277, 2008
Diameter control of electrospun polyacrylonitrile/iron acetylacetonate ultrafine nanofibers
Authors: Du Jinmei , Shintay Samantha , Zhang Xiangwu 
Published: June 2008

AbstractElectrospinning is the process of producing ultrafine fibers by overcoming the surface tension of a polymer solution using high voltage. In this work, the effects of both solution properties (viscosity, conductivity, and surface tension) and operational conditions (voltage, feed rate, and spinneret‐collector distance), on the structure of electrospun polyacrylonitrile nanofibers, were systematically investigated. Iron acetylacetonate was added to the electrospinning solution to control fiber diameter by selectively adjusting solution properties. It was found that, with increased salt concentration, the fiber diameter increases and then passes through a maximum due to changes in solution viscosity, conductivity, and surface tension. In addition, the fiber diameter increases with increase in voltage, feed rate, and spinneret‐collector distance. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1611–1618, 2008