bluuebunny/crossref_metadata_2025 huggingface dataset:
Deciphering the proteomic profile of Mycobacterium leprae cell envelope
Authors: Marques Maria Angela M. , Neves‐Ferreira Ana Gisele C. , da Silveira Erika K. Xavier , Valente Richard H. , Chapeaurouge Alexander , Perales Jonas , da Silva Bernardes Renato , Dobos Karen M. , Spencer John S. , Brennan Patrick J. , Pessolani Maria Cristina V.
Published: June 2008

The complete sequence of the Mycobacterium leprae genome, an obligate intracellular pathogen, shows a dramatic reduction of functional genes, with a coding capacity of less than 50%. Despite this massive gene decay, the leprosy bacillus has managed to preserve a minimal gene set, most of it shared with Mycobacterium tuberculosis, allowing its survival in the host with ensuing pathological manifestations. Thus, the identification of proteins that are actually expressed in vivo by M. leprae is of high significance in understanding obligate, intracellular mycobacterial pathogenesis. In this study, a high‐throughput proteomic approach was undertaken resulting in the identification of 218 new M. leprae proteins. Of these, 60 were in the soluble/cytosol fraction, 98 in the membrane and 104 in the cell wall. Although several proteins were identified in more than one subcellular fraction, the majority were unique to one. As expected, a high percentage of these included enzymes responsible for lipid biosynthesis and degradation, biosynthesis of the major components of the mycobacterial cell envelope, proteins involved in transportation across lipid barriers, and lipoproteins and transmembrane proteins with unknown functions. The data presented in this study contribute to our understanding of the in vivo composition and physiology of the mycobacterial cell envelope, a compartment known to play a major role in bacterial pathogenesis.
Identification of protein components from the mature ovary of the sea urchin Evechinus chloroticus (Echinodermata: Echinoidea)
Authors: Sewell Mary A. , Eriksen Soren , Middleditch Martin J.
Published: June 2008

The gonads of sea urchins are a high value seafood product, with considerable research being undertaken worldwide on the development of sea urchin aquaculture. As the best prices are obtained for specific gonad attributes, research has also focused on the development of artificial diets that enhance gonad quality and quantity. Total protein has been used as a measure of gonad quality; yet no studies to date have applied proteomics technology to diet development. Here we use a MudPIT and 2‐DE approach to describe the major proteins in mature ovaries of a New Zealand sea urchin Evechinus chloroticus. This tissue, which is a target seafood product, contained 138 proteins that were identified from the recently completed sea urchin genome (Strongylocentrotus purpuratus) with high confidence. The majority of these proteins had general functions, with only 12 related to ovarian reproductive function. Eighteen proteins were located on the 2‐DE; four of these were directly identified from S. purpuratus protein sequences. In combination this paper shows that the genome resources of S. purpuratus can be used to identify proteins in sea urchins from different families; describes the proteome of E. chloroticus mature ovary; and, provides proteomic tools for analysis of gonads from other edible sea urchins.
Comparative proteomic analysis of PAI‐1 and TNF‐alpha‐derived endothelial microparticles
Authors: Peterson Danielle B. , Sander Tara , Kaul Sushma , Wakim Bassam T. , Halligan Brian , Twigger Simon , Pritchard Kirkwood A. , Oldham Keith T. , Ou Jing‐Song
Published: June 2008

Endothelium‐derived microparticles (EMPs) are small vesicles released from endothelial cells in response to cell injury, apoptosis, or activation. Elevated concentrations of EMPs have been associated with many inflammatory and vascular diseases. EMPs also mediate long range signaling and alter downstream cell function. Unfortunately, the molecular and cellular basis of microparticle production and downstream cell function is poorly understood. We hypothesize that EMPs generated by different agonists will produce distinct populations of EMPs with unique protein compositions. To test this hypothesis, different EMP populations were generated from human umbilical vein endothelial cells by stimulation with plasminogen activator inhibitor type 1 (PAI‐1) or tumor necrosis factor‐alpha (TNF‐α) and subjected to proteomic analysis by LC/MS. We identified 432 common proteins in all EMP populations studied. Also identified were 231 proteins unique to control EMPs, 104 proteins unique to PAI‐1 EMPs and 70 proteins unique to TNF‐α EMPs. Interestingly, variations in protein abundance were found among many of the common EMP proteins, suggesting that differences exist between EMPs on a relative scale. Finally, gene ontology (GO) and KEGG pathway analysis revealed many functional similarities and few differences between the EMP populations studied. In summary, our results clearly indicate that EMPs generated by PAI‐1 and TNF‐α produce EMPs with overlapping but distinct protein compositions. These observations provide fundamental insight into the mechanisms regulating the production of these particles and their physiological role in numerous diseases.
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

Chromium (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

Proteolysis, 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

Cadmium (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

We 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

Ischemia/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

To 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

Two 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

The 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

Ethyl‐(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

The 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

Vinyl 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

We 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

Lanthanum 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

Soluble 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

Homogeneous 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

A 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

Reaction 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

The 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

Electrospinning 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
Rheology, electrical conductivity, and the phase behavior of cocontinuous PA6/ABS blends with MWNT: Correlating the aspect ratio of MWNT with the percolation threshold
Authors: Bose Suryasarathi , Bhattacharyya Arup R. , Bondre Ameya P. , Kulkarni Ajit R. , Pötschke Petra
Published: June 2008

Multiwalled carbon nanotubes (purified, p‐MWNT and ∼ NH2 functionalized, f‐MWNT) were melt‐mixed with 50/50 cocontinuous blends of polyamide 6 (PA6) and acrylonitrile–butadiene–styrene in a conical twin‐screw microcompounder to obtain conductive polymer blends utilizing the conceptual approach of double‐percolation. The state of dispersion of the tubes was assessed using AC electrical conductivity measurements and melt‐rheology. The rheological and the electrical percolation threshold was observed to be ∼ 1–2 wt % and ∼ 3–4 wt %, respectively, for blends with p‐MWNT. In case of blends with f‐MWNT, the rheological percolation threshold was observed to be higher (2–3 wt %) than p‐MWNT but the electrical percolation threshold remained almost same. However, the absolute values were significantly lower than blends with p‐MWNT. In addition, significant refinement in the cocontinuous morphology of the blends with increasing concentration of MWNT was observed in both the cases. Further, an attempt was made to understand the underlying concepts in relation to cocontinuous morphologies that how the geometrical percolation threshold which adversely suffered because of the attrition of tubes under prolonged shear contributed further in retaining the rheological percolation threshold. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1619–1631, 2008
The effects of monophenol chain terminators on the structure–property relationships of controlled epoxy networks
Authors: Marks Maurice J. , Verghese Nikhil E. , Hrovat K. James , Laboy‐Bollinger Anamari , Buck James C. , Rabon James A. , O'connell Carol L. , Allen Lisa
Published: June 2008

Five families of new controlled epoxy thermosets (CENs) using three monophenol chain terminators were prepared to study systematic changes in the structure and amount of the monophenol and the initial molecular weight between crosslinks (Mc,i) on the properties of epoxy thermosets. Glass transition temperature (Tg) decreases with monophenol mole fraction (χ) in proportion to both the concentration and flexibility of the chain terminator. Distinct serial relations forTgdepression were observed for the threeMc,ifamilies. Dynamic mechanical analysis (DMA) shows significant perturbations of the relaxation behavior with added terminator as evidenced by decrease in peak tan δ and in postTgdamping. The rubbery coefficients of thermal expansion (CTE) increases with monophenol concentration only at χ > 0.05 and shows distinct curvature versus temperature, but is largely invariant with monophenol flexibility. The thermal stability of terminated CENs decreases only slightly with χ and little difference was found with monophenol structure. Most surprisingly, fracture toughness decreases markedly and discontinuously with χ depending onMc,i. The values of the critical monophenol concentration at which fracture toughness markedly decreases (χc) are inversely proportional toMc,ibut are independent of monophenol flexibility. No correlation of χcwith any of the calculated network structure parameters was apparent. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1632–1640, 2008
The urine proteome as a biomarker of radiation injury
Authors: Sharma Mukut , Halligan Brian D. , Wakim Bassam T. , Savin Virginia J. , Cohen Eric P. , Moulder John E.
Published: June 2008

Terrorist attacks or nuclear accidents could expose large numbers of people to ionizing radiation, and early biomarkers of radiation injury would be critical for triage, treatment, and follow‐up of such individuals. However, no such biomarkers have yet been proven to exist. We tested the potential of high throughput proteomics to identify protein biomarkers of radiation injury after total body X‐ray irradiation (TBI) in a rat model. Subtle functional changes in the kidney are suggested by increased glomerular permeability for macromolecules measured within 24 h after TBI. Ultrastructural changes in glomerular podocytes included partial loss of the interdigitating organization of foot processes. Analysis of urine by LC‐MS/MS and 2‐DE showed significant changes in the urine proteome within 24 h after TBI. Tissue kallikrein 1‐related peptidase, cysteine proteinase inhibitor cystatin C and oxidized histidine were found to be increased while a number of proteinase inhibitors including kallikrein‐binding protein and albumin were found to be decreased postirradiation. Thus, TBI causes immediately detectable changes in renal structure and function and in the urinary protein profile. This suggests that both systemic and renal changes are induced by radiation and it may be possible to identify a set of biomarkers unique to radiation injury.
Proteins and protein fragments in nephrotic syndrome: Clusters, specificity and mechanisms
Authors: Candiano Giovanni , Bruschi Maurizio , Petretto Andrea , Santucci Laura , Del Boccio Piero , Urbani Andrea , Bertoni Elisabetta , Gusmano Rosanna , Salvadori Maurizio , Scolari Francesco , Ghiggeri Gian Marco
Published: June 2008

Proteinuria is the hallmark of renal diseases and the characterization of the urinary protein composition may become an important source of information for diagnosis and research. So far, protein analysis in urine has been utilized for a generic individuation of site‐specific defects (glomerular vs. tubular) but there is a need for an extension of proteomics to specific urinary biomarkers in selected clinical conditions. The identification of fragments of proteins in plasma and urine may increase the spectrum of urinary biomarkers. The unique speculative application so far proposed for protein fragments is nephrotic syndrome, and specifically focal segmental glomerulosclerosis, in which case they reflect intrinsic proteolysis occurring in plasma and represent surrogate biomarkers of the disease activity. Albumin is probably the most studied protein. Several of the albumin fragments present a peculiar distribution of the fingerprint peptide pattern containing both the N‐terminal region and the C‐terminal domain with a complete lack of any MS signals for the internal sequence region. Their characterization utilizing new strategies based on 2‐D nondenaturing electrophoresis is now in progress. Studies on a direct characterization of proteases in plasma and urine will also define the participation of proteases to the genesis of renal diseases.
Axin2 expression identifies progenitor cells in the murine prostate
Authors: Ontiveros Christopher S. , Salm Sarah N. , Wilson E. Lynette
Published: June 2008

BACKGROUND

We previously reported that prostatic stem/progenitor cells are concentrated in the proximal region of prostatic ducts and express stem cell antigen 1 (Sca‐1). As Wnt signaling is important for the maintenance of stem cells, we determined whether Sca‐1 expressing cells also express Axin2, as Axin2 expression is highly suggestive of active Wnt signaling.

METHODS

Axin2 promoter reporter mice were used for whole mount and fluorescence activated cell sorting (FACS) analysis to determine its expression in the prostate. Axin2 expressing cells were also examined for the co‐expression of Sca‐1. We also used a chemical activator of Wnt signaling, BIO, to determine the effects of Wnt signaling on the growth of primary prostate cells in vitro.

RESULTS

We show that Axin2 expression is present in all lobes and is regulated by androgens with the highest Axin2 expression in the lateral and dorsal prostate. Furthermore, a fraction of Axin2 expressing cells co‐express Sca‐1, suggesting that some progenitor cells have active Wnt signaling. Lastly, we demonstrate that activation of the Wnt pathway may result in increased growth, consistent with a role for Wnt signaling in maintenance and/or expansion of the progenitor cell population.

CONCLUSION

Axin2 expressing cells that co‐express Sca‐1 are present in all prostate lobes suggesting that progenitor cells reside within the Wnt active population. An understanding of the basic biology of signaling pathways mediating growth in the prostate may lead to rational therapies to treat benign prostatic hyperplasia and prostate cancer. Prostate 68:1263–1272, 2008. © 2008 Wiley‐Liss, Inc.
ERAP75 functions as a coactivator to enhance estrogen receptor α transactivation in prostate stromal cells
Authors: Chen Ming , Ni Jing , Zhang Yong , Muyan Mesut , Yeh Shuyuan
Published: June 2008

BACKGROUND

Estrogen receptor α (ERα) has been reported to be expressed and function in the prostate stromal cells, and numerous evidences indicated that the stromal ERα signal pathway plays critical roles in prostate development and cancer. ERα requires distinct coregulators for efficient transcriptional regulation. The goal of this study is to examine physical and functional interaction between ERα and ERAP75 in the context of prostate stromal cells.

METHOD

Yeast two‐hybrid assays were used to screen novel ERα interaction proteins. The interaction between ERα and ERAP75 was confirmed by mammalian two‐hybrid, GST pull‐down, and co‐immunoprecipitation methods. The interaction motif was examined by site‐directed mutagenesis. The effect of ERAP75 on ERα transactivation and the expression of ERα target genes were determined by luciferase assay and real‐time PCR, respectively.

RESULT

ERα can interact with the C terminus of ERAP75 via its ligand binding domain both in vivo and in vitro. The conserved LXXLL motif within the C terminus of ERAP75 is required for the interaction between ERα and ERAP75. ERAP75 can enhance ERα transactivation in a dose‐dependent manner and up‐regulate the expression of the endogenous ERα target gene, stromal‐derived factor‐1 (SDF‐1), in the prostate stromal cells.

CONCLUSION

ERAP75 functions as a novel coactivator that can modulate ERα function in the prostate stromal cells. The understanding of the mechanism of ERα transactivation in prostate stromal cells could possibly help in the development of new strategies to control or treat prostate cancer by targeting its transactivation protein complex. Prostate 68:1273–1282, 2008. © 2008 Wiley‐Liss, Inc.
Opioid use in palliative care: available options and concerns
Authors: Gishen Faye , Tookman Adrian , Kurowska Anna
Published: June 2008

The correct use of opioids is the mainstay of effective management of pain in palliative care. The authors describe the available analgesic options and explore patient and doctor concerns associated with their use. Copyright © 2008 Wiley Interface Ltd
Beta‐blockers in the treatment of cardiovascular disease
Authors: Cullington Damien , Yassin Ashraf , Cleland John
Published: June 2008

Beta‐blockers are widely used drugs in the treatment of angina, heart failure and atrial fibrillation and following MI. Our Drug review considers their properties and current place in therapy, followed by sources of further information and a review of prescription data. Copyright © 2008 Wiley Interface Ltd
Zoledronic acid: a once‐yearly injection for osteoporosis
Authors: Chaplin Steve , Dennison Elaine
Published: June 2008

Aclasta is a once‐yearly injection of the bisphosphonate zoledronic acid that offers much improved adherence compared with oral bisphosphonates. In our New products review Steve Chaplin presents the clinical data relating to its efficacy and adverse effects, and Dr Elaine Dennison comments on its place in therapy. Copyright © 2008 Wiley Interface Ltd
Structural characterization of a neurotoxic threonine‐rich peptide corresponding to the human prion protein α2‐helical 180–195 segment, and comparison with full‐length α2‐helix‐derived peptides
Authors: Ronga Luisa , Palladino Pasquale , Saviano Gabriella , Tancredi Teodorico , Benedetti Ettore , Ragone Raffaele , Rossi Filomena
Published: June 2008

The 173–195 segment corresponding to the helix 2 of the globular PrP domain is a good candidate to be one of the several ‘spots’ of intrinsic structural flexibility, which might induce local destabilization and concur to protein transformation, leading to aggregation‐prone conformations. Here, we report CD and NMR studies on the α2‐helix‐derived peptide of maximal length (hPrP[180–195]) that is able to exhibit a regular structure different from the prevalently random arrangement of other α2‐helix‐derived peptides. This peptide, which has previously been shown to be affected by buffer composition via the ion charge density dependence typical of Hofmeister effects, corresponds to the C‐terminal sequence of the PrPC full‐length α2‐helix and includes the highly conserved threonine‐rich 188–195 segment. At neutral pH, its conformation is dominated by β‐type contributions, which only very strong environmental modifications are able to modify. On TFE addition, an increase of α‐helical content can be observed, but a fully helical conformation is only obtained in neat TFE. However, linking of the 173–179 segment, as occurring in wild‐type and mutant peptides corresponding to the full‐length α2‐helix, perturbs these intrinsic structural propensities in a manner that depends on whether the environment is water or TFE. Overall, these results confirm that the 180–195 parental region in hPrPC makes a strong contribution to the chameleon conformational behavior of the segment corresponding to the full‐length α2‐helix, and could play a role in determining structural rearrangements of the entire globular domain. Copyright © 2008 European Peptide Society and John Wiley & Sons, Ltd.
Cathodic electrodeposition of ZnCoO thin films
Authors: Tortosa M. , Mollar M. , Manjón F. J. , Marí B. , Sánchez‐Royo J. F.
Published: June 2008

We report on the characterization of ternary Zn1–xCoxO alloy crystalline films grown by electrodeposition onto FTO‐coated substrates. The Zn1–xCoxO films have hexagonal wurtzite structure as shown by X‐ray diffraction measurements. The Co incorporation into the ZnO lattice is confirmed by the presence of absorption peaks assigned to Co in trigonal crystal field. X‐ray photoemission spectroscopy indicates that as‐grown films have a considerable concentration of not‐fully oxidized metallic Co in the surface that correlates with the O concentration in the surface. Finally, Raman measurements of as‐grown films indicate that they are polycrystalline with grains of nanometric size showing short‐range order but no long‐range order. The Raman spectra show no trace of first‐order phonons and resemble the one‐and two‐phonon density of states of ZnO (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of pentacene based organic thin film transistor using conductive carbon electrode
Authors: Park Yong Seob , Kim Kyo Hyeok , Kim Hyung Jin , Chung Ilsub , Hong Byungyou
Published: June 2008

Amorphous carbon films prepared by our experiments exhibited very low resistivity (< 1 mΩ·cm) and good conductivity without any dopant. So, we applied to the gate electrodes for organic thin film transistor (OTFTs). The conductive carbon film used as the electrodes has properties such as good adhesion to glass and plastic substrate, good physical properties for the lifetime of electrodes, good electrical properties, thermal stability and high transparency. In this work, we have fabricated organic thin film transistors (OTFTs) of a back gate structure using the pentacene active region on polyvinylphenol (PVP) as gate dielectric. We fabricated three different types of transistors using pentacene film grown on PVP gate dielectric with gate electrodes of N++Si, Au, and conductive carbon (a‐C) films. We investigated the current image property of two structures by using the SPM method and compared the topology with its current images, which were simultaneously obtained by scanning a 3 μm × 3 (m region. The current images of OTFT with the different gate electrodes have shown that the vertical leakage current flows along the pentacene grain edges. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of solution concentration and temperature on the aqueous chemical growth of zinc oxide structures
Authors: Vernardou D. , Kenanakis G. , Vlachou K. , Koudoumas E. , Kiriakidis G. , Vairis A. , Katsarakis N.
Published: June 2008

ZnO was deposited on Corning glass using an equimolar aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine by Aqueous Chemical Growth. The morphological characteristics of the as‐grown ZnO structures can be varied by adjusting the precursor solution concentration and solution temperature. An increase in the precursor solution concentration induces a modification in the ZnO morphology from sub‐microrod to flower‐like and microrod structures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Correlation between the stress in ZnO thin films and the Urbach band tail width
Authors: Dimova‐Malinovska D. , Nichev H. , Angelov O.
Published: June 2008

A comparison of the changes in the optical and structural properties of ZnO thin films, undoped and doped with Al, Er and Ta, deposited by magnetron co‐sputtering in Ar is performed in this work. A set of ZnO samples deposited by sputtering in Ar+H2 is studied, as well. The films are deposited at different substrate temperatures and with different concentrations of the doping elements. The band gap energy and the Urbach band tail parameter are calculated from the spectral dependence of the coefficient of absorption. The stresses in the films are calculated from X‐ray diffraction patterns. A correlation between the band tail widths and the stress in the ZnO thin films is observed. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Low temperature Al doped ZnO films on a flexible substrate by DC sputtering
Authors: Lee Kyu‐Il , Kim Eung Kwon , Kim Hyun‐Duk , Kang Hyun‐Il , Song Joon‐Tae
Published: June 2008

The target of Al doped ZnO was prepared. AZO thin films were deposited on PolyCarbonate (PC) by the DC sputtering method. The thickness of films was controlled to within about 400 nm. Thin films fabricated on a PC substrate were compared to those fabricated on glass and quartz. The resistivity of Al doped ZnO (AZO) films deposited on a PC substrate was 4.5×10–3 Ω‐cm. The transmittance of all films exceeded 80% across the visible spectrum. AZO deposited on PC was compared to AZO deposited on a rigid substrate and Ga doped ZnO (GZO) deposited on PC, to identify characteristic differences such as the substrate, and characteristic differences with respect to the atomic radius of impurity atoms. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)