bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cloning, sequence, and function analyses of giant panda (Ailuropoda melanoleuca) CD9 gene
Authors: Tang Yang , Tan Xue‐Mei , Yue Chang‐Wu , Li Cai‐Xia , Fan Zhao‐Xin , Zhang Yi‐Zheng 
Published: March 2008

AbstractCD9 is a member of the tetraspanin family proteins and has recently been shown to be essential for sperm–oocyte fusion in mice. The giant panda (Ailuropoda melanoleuca) CD9 (gpCD9) cDNA was amplified for the first time by RT‐PCR from ovary total RNA and cloned, sequenced and analyzed. The result revealed that the open reading frame (ORF) of gpCD9 was 681 bp, which has the same length as that of mouse. Sequence analysis and structure prediction displayed that the amino acid sequence of gpCD9 is over 80% identity to those of mammals with the conserved structures, including the four transmembrane domains (TM) and certain characteristic residues. The results of sperm–egg fusion experiments demonstrated that giant panda CD9 large extracellular loop (LEL) significantly inhibited (P < 0.05) the mouse gamete fusion when the recombinant protein was added. However, when three amino acid residues TVT (173–175) of the gpCD9 were mutated to AAA, the large extracellular loop (LELM) of mutated protein was rarely inhibiting the gamete fusion of mice. Our results may be useful in improving an insight into understanding the potential mechanism of gamete fusion and genetic characteristics of giant panda. Mol. Reprod. Dev. 75: 1418–1425, 2008. © 2008 Wiley‐Liss, Inc.
Mathematical modeling of boundary conditions for laser‐molecule time‐dependent Schrödinger equations and some aspects of their numerical computation—One‐dimensional case
Authors: Lorin Emmanuel , Chelkowski S. , Bandrauk A.D. 
Published: March 2008

AbstractThis article deals with boundary conditions for time‐dependent Schrödinger equations for molecules excited by intense and ultrashort electric fields. On the basis of Volkov wavefunctions, we propose an original boundary condition design that allows to reduce spurious reflections at the domain boundary and allows to take at least partially, plasma effects into account. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Variational formulation of the material failure process in solids by embedded discontinuities model
Authors: Juárez Gelacio , Ayala Gustavo 
Published: March 2008

AbstractThis work presents a variational formulation of the material failure process, idealized as strain or displacement discontinuities, by weak, strong, or discrete embedded discontinuities into a continuum. It is shown that the solution of the proposed variational formulation may be approximated by different types of finite elements with embedded discontinuities. The developed displacement approximation of a finite element split by the discontinuity leads to a symmetric stiffness matrix, which considers not only the continuity of tractions but also the rigid body relative motions of the portions in which the element is split. The variational formulation of a continuum with more than one discontinuity in its interior is developed. It is shown that this formulation may lead to finite elements with embedded discontinuities that can be classified as displacement, force, mixed, and hybrid models. To show the effectiveness of the proposed formulation, the classical example of a bar under tension is solved using one and 2D finite element approximations. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Preparation and characterization of compatible thermoplastic dry starch/poly(lactic acid)
Authors: Wang Ning , Yu Jiugao , Ma Xiaofei 
Published: March 2008

AbstractIn the presence of glycerol and formamide, one‐step extrusion processing was used to prepare poly(lactic acid) (PLA)/thermoplastic dry starch (DTPS) blends (50/50 wt%) in a single‐screw extruder. The rheological study proved that formamide could improve the fluidity of DTPS and DTPS/PLA blends. With increasing the fluidity of DTPS, a highly dispersed and compatible DTPS/PLA could be achieved by scanning electron microscope (SEM). It was also certain that the plasticization of DTPS was improved. At the same time, Fourier transform infrared (FT‐IR) spectroscopy proved that formamide not only weakened the interaction of starch molecules, but also improved the interaction between DTPS and PLA. So that the blend could achieve more thermal stability in a compatible blend, as shown in TGA. The improvement of compatible in DTPS/PLA blends was also proved by tensile test and Dynamic mechanical thermal analysis (DMTA) in this article. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Dielectric and conduction properties of polyimide/silica nano‐hybrid films
Authors: Zhang Ming‐Yan , Zeng Shu‐Jin , Fan Yong , Zhang Pei‐Hong , Lei Qing‐Quan 
Published: March 2008

AbstractDielectric and conduction properties of polyimide/silica nano‐hybrid films were investigated with the silica content and the testing frequency, using a small electrode system. The hybrid films were prepared through sol‐gel process and thermal imidization, by using pyromellitic dianhydride and 4,4′‐oxydianiline as polyimide precursors, and tetraethoxysilane and methyltriethoxysilane as silica precursors. The dielectric coefficient of PI/SiO2 films was monotonically increased with increasing silica content, and decreased with increasing testing frequency. The dielectric loss of PI/SiO2 films had no obvious changes with increasing silica content, but monotonically increased with increasing testing frequency. These can be contributed to the different quantity and migration chunnels of current carriers, which were mainly influenced by a few of complicated factors. There were remarkable differences between conduction property of PI/TEOS‐SiO2 films and PI/MTEOS‐SiO2 films because of the different size and dispersion status of silica particles in the polyimide matrix. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Synthesis and characterization of poly(trimethylene terephthalate)/polyhedral oligomeric silsesquixanes nanocomposites
Authors: Kim Kap Jin , Ramasundaram Subramaniyan , Lee Jong Soon 
Published: March 2008

AbstractThis article reports the preparation of poly(trimethylene terephthalate) (PTT)– polyhedral oligomeric silsesquioxanes (POSS) nanocomposites through in situ polymerization. The chemical structure of the PTT–POSS nanocomposites was characterized with Fourier‐transform infrared and nuclear magnetic resonance spectroscopies and the presence of POSS was further confirmed by the elemental analysis. The crystal structures as well as the position of POSS in the nanocomposites were ascertained by the X‐ray diffraction (XRD) studies. Thermal characterization studies showed the gradual decrease in the glass transition and melt crystallization temperatures. Though the thermal stability of the PTT was not affected by the incorporation of POSS, the amount of residues obtained from thermal degradation process was increased with an increase in the content of POSS. The tensile studies showed that the values of initial modulus and breaking strength were dramatically decreased with an increase in the content of POSS. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
A comparative study on mechanical properties and water absorption behavior of fiber‐reinforced polypropylene composites prepared by OCC fiber and aspen fiber
Authors: Ashori Alireza , Nourbakhsh Amir 
Published: March 2008

AbstractFiber‐reinforced polymers have received considerable attention from industry in recent years. Due to the sharp ecological damage, worldwide shortage of trees in many areas and the global demand for fibrous material, there has been growing interest in the use of recycled wood fiber as an alternative or substitute fiber source. The present study investigates the tensile, flexural, Izod impact, and water absorption behavior of Old Corrugated Container (OCC) and aspen (AS) reinforced polypropylene (PP) composites as a function of fiber content. The surface of AS and OCC fibers was modified through the use of MAPP coupling agent. From the studies it was found that mechanical properties increase with increase in fiber loading in both cases. However the addition of wood fibers resulted in a decrease in impact strength of the composites. The water absorption property at varying fiber loading were evaluated and found maximum for the OCC/PP composites. The weight gains for all specimens were less than 3.5%. Finally, the results showed the usefulness of OCC fiber as a good alternative and reinforcing agent for composite. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers
Effect of mold temperature on the long‐term viscoelastic behavior of polybutylene terepthalate
Authors: Banik K. , Mennig G. 
Published: March 2008

AbstractThe effect of mold temperature variation during injection molding on the long‐term viscoelastic behavior of polybutylene terepthalate (PBT) was studied by dynamic mechanical thermal analysis (DMTA) and flexural creep tests. The time–temperature superposition (TTS) principle was applied to the experimental data and the master curves were created to predict their long‐term behavior. The WLF and Arrhenius models were verified for the shift data in the investigating temperature range and the activation energies for the deformation process were calculated based on the Arrhenius equation. Further a four‐element Burger model was applied to the creep results to represent the creep behavior of the PBT processed at two different mold temperatures and to better understand the deformation mechanism. Differential scanning calorimetry (DSC) and density measurements were accomplished to characterize the process‐dependent microstructures. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Gas‐assisted injection molded polypropylene: The skin‐core structure
Authors: Zheng Guo‐Qiang , Yang Wei , Yang Ming‐Bo , Chen Jing‐Bo , Li Qian , Shen Chang‐Yu 
Published: March 2008

AbstractIn this article, gas penetration‐induced skin‐core structure of isotactic polypropylene(iPP), which is molded by gas‐assisted injection molding at different gas pressures, was investigated. For comparison, the counterpart was also molded by conventional injection molding (CIM) using the same processing parameters but without gas penetration. They were characterized via PLM, DSC, and SEM. And the crystal morphology at different gas pressures was principally concerned. For the GAIM parts, highly oriented structure is formed in the skin zone, and much less oriented structure in the inner zone (near the gas channel surface). Furthermore, it is suggested that the naked shish structure can be developed in the skin zone of GAIM part, which is molded at higher gas pressures, and shish‐kebab structure is mainly formed in the skin zone of that, which is molded at lower gas pressure. However, for the CIM part, from the skin to the core zone, the dominant morphological feature is spherulite. In a word, the presence of gas penetration notably enhances the oriented structure formation and gives rise to the skin‐core structure. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Semiconductive composites from ethylene 1‐octene copolymer and polyaniline coated nylon 6: Studies on mechanical, thermal, processability, electrical, and EMI shielding properties
Authors: Bhadra Sambhu , Singha Nikhil K. , Khastgir Dipak 
Published: March 2008

AbstractIn‐situ coating of polyaniline (PAni) on nylon 6 filaments was carried out by oxidative emulsion polymerization of aniline in presence of nylon 6 filaments. The semiconducting composites were prepared by mixing polyaniline coated Nylon 6 (PN6) with a polyolefinic thermoplastic elastomer namely ethylene 1‐octene copolymer (EN). The effect of composition on different mechanical, dynamic mechanical, thermal, electrical properties, morphology, processability, and electromagnetic interference (EMI) shielding efficiency (SE) of these composites were investigated. The results revealed that the increased incorporation of PN6 in EN caused increase in modulus, hardness, glass transition temperature (Tg), apparent shear viscosity, electrical properties, EMI SE but caused decrease in the tensile strength, elongation at rupture, damping character, and die‐swell during injection molding. There are linear increase in AC conductivity and exponential decay in relative dielectric constant with the increase in applied pressure on composites. When a composite is subjected to electron beam (EB) radiation some cross‐links are formed. Mechanical properties of the composite after radiation treatment found to improve. Flow behavior shows the material is pseudo‐plastic in nature. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Synthesis and applications of water‐dispersible microspheres containing arborescent PAMAM surfaces
Authors: Jin Lan , Liu Hongbo , Yang Wuli , Wang Changchun , Yu Kui 
Published: March 2008

AbstractThis manuscript reports on a novel synthetic approach to engineer water‐dispersible microspheres with short poly(amidoamine) (PAMAM) chain grafted on their surface. These core‐shell polymeric microspheres have a large amount of amine groups on their surface obtained via “starburst” reactions. First, monodispersed poly (methyl methacrylate)‐co‐poly(glycidyl methacrylate) (P(MMA/GMA)) microspheres were prepared by surfactant‐free emulsion polymerization. Afterwards, Michael reaction and subsequent amidation reactions were carried out repetitively to synthesize arborescent PAMAM chains grafted on the surface of the P(MMA/GMA) microspheres. The resulting PAMAM‐grafted microspheres exhibit good dispersibility in aqueous environments. Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) demonstrate the successful grafting; furthermore, the crosslink degree of the P(MMA/GMA) microspheres as well as the PAMAM chain length affect the stability of the resulting core‐shell microspheres, as experimentally tested by heat treatment and acidic treatment. Easily, the PAMAM chains are protonated at low pH, and are thus able to effectively adsorb negatively‐charged magnetic nanoparticles. Bright photoluminescent (PL) water‐dispersible polymeric microspheres are fabricated readily via the reaction of the surface amine groups and traditional fluorescent molecules, namely fluorescein isothiocyanate (FITC). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2948–2959, 2008
Synthesis and self‐assembly of helical polypeptide‐random coil amphiphilic diblock copolymer
Authors: Kuo Shiao‐Wei , Lee Hsin‐Fang , Huang Chih‐Feng , Huang Cheng‐Jynn , Chang Feng‐Chih 
Published: March 2008

AbstractThree amphiphilic rod‐coil diblock copolymers, poly(2‐ethyl‐2‐oxazoline‐b‐γ‐benzyl‐L‐glutamate) (PEOz‐b‐PBLG), incorporating the same‐length PEOz block length and various lengths of their PBLG blocks, were synthesized through a combining of living cationic andN‐carboxyanhydride (NCA) ring‐opening polymerizations. In the bulk, these block copolymers display thermotropic liquid crystalline behavior. The self‐assembled aggregates that formed from these diblock copolymers in aqueous solution exhibited morphologies that differed from those obtained in α‐helicogenic solvents, that is, solvents in which the PBLG blocks adopt rigid α‐helix conformations. In aqueous solution, the block copolymers self‐assembled into spherical micelles and vesicular aggregates because of their amphiphilic structures. In helicogenic solvents (in this case, toluene and benzyl alcohol), the PEOz‐b‐PBLG copolymers exhibited rod‐coil chain properties, which result in a diverse array of aggregate morphologies (spheres, vesicles, ribbons, and tube nanostructures) and thermoreversible gelation behavior. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3108–3119, 2008
Green polymer chemistry: Telechelic poly(ethylene glycol)s via enzymatic catalysis
Authors: Puskas Judit E. , Sen Mustafa Y. , Kasper Joseph R. 
Published: March 2008

AbstractThis article reports our discovery that poly(ethylene glycol) (PEG) can quantitatively be functionalized by transesterification using Candida antarctica lipase B (Novozyme 435) as the catalyst. α‐ω telechelic PEG‐methacrylates and PEG‐acetates were successfully prepared using commercially available PEGs with both narrow and broad molecular weight distribution. 1H and 13C NMR together with MALDI‐TOF mass spectroscopy verified the expected structures. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3024–3028, 2008
Akt down‐modulation induces apoptosis of human prostate cancer cells and synergizes with EGFR tyrosine kinase inhibitors
Authors: Festuccia Claudio , Gravina Giovanni Luca , Muzi Paola , Millimaggi Danilo , Dolo Vincenza , Vicentini Carlo , Bologna Mauro 
Published: March 2008

AbstractBACKGROUNDPTEN is a well‐characterized tumor suppressor that negatively regulates cell growth and survival through the modulation of PI3K/Akt pathway.METHODSIn this paper, we investigated the effects of an PI3K/Akt inhibitor, perifosine, in human prostate cancer (PCa) cells analyzing cell proliferation, apoptosis, and the synergy with EGFR inhibitors.RESULTSClinically achievable concentrations of perifosine, as well as Akt gene knockdown, induced a G0/G1 arrest and apoptosis in PTEN defective PCa cells. Although PTEN introduction was able to restore the control of Akt activity and to reduce cell proliferation, the manipulation of PTEN gene was not able alone to influence apoptosis. Perifosine induced apoptotic program also in PTEN positive cells when Akt activity was augmented by EGF suggesting the possibility that this drug could be used in combination with EGFR inhibitors. The combination treatment between erlotinib and pharmacological or molecular Akt knockdown, indeed, showed synergistic effects. This is the first demonstration that a pharmacological compound against Akt activity can restore the efficacy against EGFR inhibitors in PCa and has important therapeutic fallout since EGFR inhibitors have demonstrated very low effectiveness in PCa patients.CONCLUSIONSTaken together our data have an important clinical relevance in the treatment of advanced prostate tumors. However, further studies in the setting of combination therapies in advanced PCas are necessary. Prostate 68:965–974, 2008. © 2008 Wiley‐Liss, Inc.
Characterization of PacMetUT1, a recently isolated human prostate cancer cell line
Authors: Troyer D.A. , Tang Y. , Bedolla R. , Adhvaryu S.G. , Thompson I.M. , Abboud‐Werner S. , Sun L.‐Z. , Friedrichs W.E. , deGraffenried L.A. 
Published: March 2008

AbstractBACKGROUNDExisting prostate cancer cell lines have limitations.METHODSCells were characterized using Western blotting, immunohistochemistry, invasion into Matrigel, and by studying xenograft tumors.RESULTSWe describe a cell line (PacMetUT1) isolated from a lymph node of a 57‐year‐old male with prostate cancer. Compared to existing prostate cancer cell lines, the growth rate of PacMetUT1 xenograft tumors is slower with tumors occurring at injection sites and with metastases to lung and liver. Androgen receptor (AR) was detected in vivo by Western blotting and the cells responded to methyltrienolone (R1881). PacMetUT1 cells are more invasive in Matrigel than DU‐145, PC‐3, and LNCaP cells, and showed greater anchorage‐independent growth in soft agar. The cells do not express prostate specific antigen (PSA) in vitro or in xenografts. However, the green fluorescent protein (GFP) gene was introduced and stably expressed in PacMetUT1 cells, allowing tumor imaging in vivo. Xenograft tumors show epithelial features and are positive for keratin, epithelial membrane antigen, EGF receptor, and E cadherin. In contrast, fibroblast markers vimentin, desmin, and Factor VIII, were negative. Karyotyping showed losses of 6p, 7q, 8p, 18q, and 22q, and gains of 8q and 9q; additional genetic material was observed at 2q and 12p.CONCLUSIONThe PacMetUT1 cell line allows metastases to be assessed using a single animal model. Because of its slower growth, PacMetUT1 more closely mimics the human disease. Studies of tumor progression or metastasis can be conducted over a longer period of time. Prostate 68:883–892, 2008. © 2008 Wiley‐Liss, Inc.
Upregulation of Arc mRNA expression in the prefrontal cortex following cue‐induced reinstatement of extinguished cocaine‐seeking behavior
Authors: Zavala Arturo R. , Osredkar Tracy , Joyce Jeffrey N. , Neisewander Janet L. 
Published: March 2008

AbstractCocaine‐associated cues acquire incentive motivational effects that manifest as cue‐elicited craving in humans and cocaine‐seeking behavior in rats. Here we examine the hypothesis that neuronal processes associated with incentive motivational effects of cocaine cues involve increased expression of the plasticity‐associated gene, Arc. Rats trained to self‐administer cocaine subsequently underwent extinction training, during which cocaine‐seeking behavior (i.e., responses without cocaine reinforcement) progressively decreased. Rats were then tested for cocaine‐seeking behavior either with or without response‐contingent presentations of light/tone cues that had been previously paired with cocaine infusions during self‐administration training. Cues elicited reinstatement of cocaine‐seeking behavior and were accompanied by increased Arc mRNA levels in the orbitofrontal, prelimbic, and anterior cingulate cortices, suggesting Arc involvement in conditioned plasticity associated with incentive motivational effects of cocaine cues. Additionally, rats with a history of cocaine self‐administration and extinction exhibited upregulation of Arc expression in several limbic and cortical regions relative to saline‐yoked controls regardless of cue exposure condition, suggesting persistent neuroadaptations involving Arc within these regions. Synapse 62:421–431, 2008. © 2008 Wiley‐Liss, Inc.
Small effect of dopamine release and no effect of dopamine depletion on [18F]fallypride binding in healthy humans
Authors: Cropley Vanessa L. , Innis Robert B. , Nathan Pradeep J. , Brown Amira K. , Sangare Janet L. , Lerner Alicja , Ryu Yong Hoon , Sprague Kelly E. , Pike Victor W. , Fujita Masahiro 
Published: March 2008

AbstractMolecular imaging has been used to estimate both drug‐induced and tonic dopamine release in the striatum and most recently extrastriatal areas of healthy humans. However, to date, studies of drug‐induced and tonic dopamine release have not been performed in the same subjects. This study performed positron emission tomography (PET) with [18F]fallypride in healthy subjects to assess (1) the reproducibility of [18F]fallypride and (2) both D‐amphetamine‐induced and α‐methyl‐p‐tyrosine (AMPT)‐induced changes in dopamin release on [18F]fallypride binding in striatal and extrastriatal areas. Subjects underwent [18F]fallypride PET studies at baseline and following oral D‐amphetamine administration (0.5 mg/kg) and oral AMPT administration (3 g/70 kg/day over 44 h). Binding potential (BP) (BPND) of [18F]fallypride was calculated in striatal and extrastriatal areas using a reference region method. Percent change in regional BPND was computed and correlated with change in cognition and mood. Test–retest variability of [18F]fallypride was low in both striatal and extrastriatal regions. D‐Amphetamine significantly decreased BPND by 8–14% in striatal subdivisions, caudate, putamen, substantia nigra, medial orbitofrontal cortex, and medial temporal cortex. Correlation between change in BPND and verbal fluency was seen in the thalamus and substantia nigra. In contrast, depletion of endogenous dopamine with AMPT did not effect [18F]fallypride BPND in both striatum and extrastriatal regions. These findings indicate that [18F]fallypride is useful for measuring amphetamine‐induced dopamine release, but may be unreliable for estimating tonic dopamine levels, in striatum and extrastriatal regions of healthy humans. Synapse 62:399–408, 2008. Published 2008 Wiley‐Liss, Inc.