bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile fabrication of macroporous polyimide films with pores distributing on one side
Authors: Deng Yongqiang , Zhou Hongwei , Dang Guodong , Rao Xianhua , Chen Chunhai 
Published: January 2007

AbstractHerein, we report on direct preparation of macroporous polyimide (PI) films with pores distributing on one side, the method of which relies on sedimentation of ceramic spheres in polyamic acid (PAA) solutions in a gravitational field and imidization of PAA/ceramic spheres mixtures to obtain PI/ceramic spheres hybrid films followed by curing in dilute hydrofluoric (HF) acid. In this strategy, the curing of the hybrid films in HF acid leads to the formation of pores. The introduction of pores makes the room‐temperature dielectric constants of the macroporous films lower than that of pure PI film. Moreover, the macroporous PI films have improved Young's moduli and higher thermal stability in nitrogen atmosphere. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 261–266, 2007
Linear‐dendritic ABA triblock copolymers as nanocarriers
Authors: Adeli M. , Zarnegar Z. , Dadkhah A. , Hossieni R. , Salimi F. , Kanani A. 
Published: January 2007

AbstractLinear‐dendritic ABA triblock copolymers containing PEG were used for transport the small guest molecules such as 5,7‐dibromo‐8‐hydoxy quinoline, ibuprofen, and Congo red. Nanocarriers containing guest molecules were soluble in water and in some of the organic solvents. Encapsulated guest molecules were soluble in some of the solvents, which they cannot be solved in them solely, for example, chloroform is a very poor solvent for Congo red, but encapsulated Congo red by nanocarriers is soluble in chloroform. The linear‐dendritic copolymers/guest molecule complexes were stable at room temperature for about 10 months; during this time, guest molecules did not release from linear‐dendritic copolymers/guest molecule complexes. The controlled release of guest molecules from linear‐dendritic copolymers/guest molecule complexes in vitro conditions also was investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 267–272, 2007
Poly(ethylene terephthalate) copolymers that contain 5‐tert‐butylisophthalic acid and 1‐3/1‐4‐cyclohexanedimethanol: Synthesis, characterization, and properties
Authors: Tsai Yuhsin , Fan Cheng‐Hsing , Hung Chi‐Yuan , Tsai Fuu‐Jen 
Published: January 2007

AbstractThe effects of incorporating 5‐tert‐butylisophthalic acid (tBI) and 1‐3/1‐4 cyclohexanedimethanol (CHDM) in the polymer chain of poly(ethylene terephthalate) (PET) on the crystallization behavior and thermal, optical and tensile properties of this polyester (PETGB) were evaluated. These random copolyesters that contained between 0 and 20 mol % of CHDM and between 0 and 10 mol % of tBI units were prepared by esterification followed by melt copolycondensation. The compositions and molecular weights of the copolyesters were determined by 1H‐NMR spectroscopy and viscometry, respectively. The composition of the polyester was consistent with the composition of the feed. The intrinsic viscosities of the copolymers ranged between 0.62 and 0.74 dL/g. The thermal behaviors were investigated over the entire range of copolymer compositions, using DSC under the heating and cooling rate of 20°C/min and TGA. The copolyesters with tBI and CHDM of < 20 mol % were crystallizable, whereas the copolyesters with tBI and CHDM of ≥ 20 mol % were amorphous. They appeared to be stable up to 395°C. The optical transmissions of the amorphous polyesters were more than 88% in the visible region. The mechanical behavior was investigated by performing a tensile test. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 279–285, 2007
Isothermal cold crystallization kinetics of polylactide/nucleating agents
Authors: Liao Ruogu , Yang Bin , Yu Wei , Zhou Chixing 
Published: January 2007

AbstractThe isothermal cold crystallization kinetics of polylactide (PLA)/nucleating agents (CaCO3, TiO2, and BaSO4, content from 0.5–2.0 wt %) was investigated by differential scanning calorimetry in the temperature range of 120–124°C. With blending nucleating agents, the crystallinity of PLA had a maximum crystallinity of 14.9%. Crystallization rate decreased with increasing crystallization temperature in the researched content range. The crystallization rate followed the Avrami equation with the exponent n around 4.5. From Lauritzen–Hoffman equation, the nucleation parameter Kg was estimated. And from the value of Kg, regime II crystallization behavior can be concluded. Then the lateral and fold surface free energy were calculated from Kg. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 310–317, 2007
Statistical principal components analysis for retrieval experiments
Authors: Dinçer Bekir Taner 
Published: January 2007

AbstractIn this article, the statistical principal components analysis (PCA) is proposed as a method for performance comparisons of different retrieval strategies. It is shown that the PCA method can reveal implicit performance relations among retrieval systems across information needs (i.e., queries, topics). For illustration, the TREC 12 robust track data have been reevaluated by the PCA method and have been shown to reveal easily the performance relations that are hard to see with traditional techniques. Therefore, PCA promises a uniform evaluation framework that can be used for large‐scale evaluation of retrieval experiments. In addition to the mean average precision (MAP) measure, relative analytic distance (RAD) is proposed as a new performance summary measure based on the same notion introduced by PCA.
A Highly Fluorescent Anthracene‐Containing Hybrid Material Exhibiting Tunable Blue–Green Emission Based on the Formation of an Unusual “T‐Shaped” Excimer
Authors: Zhang Guoqi , Yang Guoqiang , Wang Shuangqing , Chen Qingqi , Ma Jin Shi 
Published: January 2007

AbstractA series of flexible bis(9‐anthryldiamine) ligands (L1–L3) linked with alkyl spacers of different chain length was synthesized and characterized, in order to investigate the coordination behavior of these diamine ligands with metal ions (Zn2+, etc.) based on fluorescence measurements. The results showed that, in the case of anthryldiamine ligands bearing two‐ or four‐carbon links, the zinc ion induced a chelation‐enhanced fluorescence (CHEF) effect in aqueous media, while a trace amount of water could selectively quench the blue emission of the ZnII complex with a three‐carbon‐linked ligand (1). Meanwhile, the introduction of more water (concentration >11 %) resulted in the formation of a new green luminescent species; the luminescence intensity was enhanced stepwise to a maximum with addition of approximately 30 % water in THF solution. The peak position (centered at approximately 500 nm) and the lifetime measurement (τ=19.59 ns) indicated that the green luminescence was attributable to a novel edge‐to‐face dimeric conformation (“T‐shaped” conformation) of anthracene, and not to the more common face‐to‐face dimeric conformation. Accordingly, 1H NMR spectroscopic studies in nonaqueous or aqueous solution confirmed this T‐shaped conformation, which is consistent with the results of single‐crystal X‐ray structure analysis and solid‐state photoluminescence studies.
Voltage mode and current mode Tow Thomas bi‐quadratic filters using inverting CCII
Authors: Soliman Ahmed M. 
Published: January 2007

AbstractA voltage mode Tow Thomas bi‐quadratic filter using the inverting second‐generation current conveyor (ICCII) is given. The filter has high input impedance, employs two grounded capacitors, and has independent control on Q, independent control on the band‐pass and low‐pass response gain. Three alternative current mode filters are generated from the voltage mode circuit. The three circuits have zero input impedance, employ grounded capacitors and have independent control on Q. Two of the circuits have also all resistors grounded and the other uses only ICCII−and has only one floating resistor. Copyright © 2007 John Wiley & Sons, Ltd.
Identification of a minimal region of loss on the short arm of chromosome 1 in Wilms tumor
Authors: Tamimi Yahya , Ziebart Kay , Desaulniers Nancy , Dietrich Kevin , Grundy Paul 
Published: January 2007

AbstractWe have analyzed the short arm of chromosome 1 using loss of heterozygosity (LOH) analysis in Wilms tumors (WT) to identify a minimal region of loss. 1909 WT, 22 malignant rhabdoid tumors of the kidney and 90 clear cell carcinomas of the kidney (CCSK) were subjected to LOH analysis using five markers flanked by D1S243 and D1S244. 225 WT and 4 CCSK displayed LOH for this region. A group of 16 cases which had lost heterozygosity for at least one locus but also retained heterozygosity for at least one locus within this region were more finely analyzed using a panel of 24 microsatellite markers. A minimum region of loss located between D1S2694 and D1S244 spanning an area of 3.23 Mb was found in 15/16 of these tumors. No evidence for a second locus within this region was identified. This region of loss overlaps that found in neuroblastoma and harbors candidate genes highly expressed in fetal kidney i.e., LZIC, ICAT, and DNB5. Denaturing HPLC and quantitative RT‐PCR analysis of these three genes, however, revealed no aberrations in WT samples retaining heterozygosity (8 cases) or displaying LOH 1p (8 cases). Further studies are required to identify the presumed tumor suppressor gene located within this region of 1p. © 2007 Wiley‐Liss, Inc.
A micro‐RNA signature associated with race, tumor size, and target gene activity in human uterine leiomyomas
Authors: Wang Tongsheng , Zhang Xinmin , Obijuru Laura , Laser Jordan , Aris Virginie , Lee Peng , Mittal Khush , Soteropoulos Patricia , Wei Jian‐Jun 
Published: January 2007

AbstractHuman uterine leiomyomas (ULMs) are the most common neoplasms of women. Many genes are dysregulated in ULMs and some of this dysregulation may be due to abnormal expression of micro‐RNAs (miRNAs). In this study, 55 ULMs and matched myometrium were collected from 41 patients for microarray‐based global miRNA expression analysis. Of 206 miRNAs examined, 45 miRNAs were significantly up‐ or down‐regulated in ULMs in comparison to the matched myometrium (P < 0.001). The top five dysregulated miRNAs in ULMs are the let‐7 family, miR‐21, miR‐23b, miR‐29b, and miR‐197. Four polycistronic clusters of miRNAs were either up‐ or down‐regulated, but not in a mixed pattern, indicative of coordinated regulation of these miRNAs. Significance analysis revealed that subsets of miRNAs were strongly associated with tumor sizes and race. By prediction analysis we identified some important tumorigenic genes previously identified in ULMs that may be targeted by the dysregulated miRNAs. HMGA2 was identified as one of target genes of the let‐7 family of miRNAs and has been found to be suppressed by let‐7 in vitro. (This article contains Supplementary material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat.) © 2007 Wiley‐Liss, Inc.
Gains of REL in primary mediastinal B‐cell lymphoma coincide with nuclear accumulation of REL protein
Authors: Weniger Marc A. , Gesk Stefan , Ehrlich Steve , Martin‐Subero José I. , Dyer Martin J. S. , Siebert Reiner , Möller Peter , Barth Thomas F. E. 
Published: January 2007

AbstractGains or amplifications of the REL locus are frequently seen in primary mediastinal B‐cell lymphoma (PMBL). In classical Hodgkin's lymphoma, genomic overrepresentation of REL correlated with nuclear REL protein accumulation. To investigate the correlation between REL gene copies and its RNA and protein expression in PMBL, we analyzed genomic, transcriptional, and protein levels in 20 PMBLs and the PMBL derived cell lines MedB‐1 and Karpas1106P. We found gains/amplifications in 75% of the PMBLs by fluorescence in situ hybridization (FISH) and genomic REL overrepresentation in the PMBL lines. Three of the five PMBLs with amplifications displayed elevated REL transcripts, while only 3/10 PMBLs with gains showed increased REL transcripts by real‐time PCR. One PMBL without gains displayed increased REL transcription. REL protein expression exhibited a variable pattern across the PMBLs except for a single case that was completely negative by immunohistochemistry despite having gained REL. Although transcript levels were generally low and nuclear REL staining was weak in the lymphoma cell lines, these nevertheless exhibited high NF‐κB activation. By fluorescence immunophenotyping and interphase cytogenetics as a tool for investigation of neoplasms, genomic gains/amplifications of REL significantly correlated with nuclear REL expression (P < 0.05). In conclusion, the frequent genomic overrepresentation of REL in PMBL does not necessarily trigger an increased transcription/translation of REL. However, combined genomic and protein analysis revealed a significant association of gained REL and nuclear REL accumulation at the single cell level. © 2007 Wiley‐Liss, Inc.
Inhibiting cell cycle progression reduces reactive astrogliosis initiated by scratch injury in vitro and by cerebral ischemia in vivo
Authors: Zhu Zhou , Zhang Qiang , Yu Zhiyuan , Zhang Liang , Tian Daishi , Zhu Suiqiang , Bu Bitao , Xie Minjie , Wang Wei 
Published: January 2007

AbstractAstrogliosis occurs in a variety of neuropathological disorders and injuries, and excessive astrogliosis can be devastating to the recovery of neuronal function. In this study, we asked whether reactive astrogliosis can be suppressed in the lesion area by cell cycle inhibition and thus have therapeutic benefits. Reactive astrogliosis induced in either cultured astrocytes by hypoxia or scratch injury, or in a middle cerebral artery occlusion (MCAO) ischemia model were combined to address this issue. In the cultured astrocytes, hypoxia induced a cell cycle activation that was associated with upregulation of the proliferating cell nuclear marker (PCNA). Significantly, the cell cycle inhibitor, olomoucine, inhibited hypoxia‐induced cell cycle activation by arresting the cells at G1/S and G2/M in a dose‐dependent manner and also reversed hypoxia‐induced upregulation of PCNA. Also in the cultured astrocytes, scratch injury induced reactive astrogliosis, such as hypertrophy and an increase in BrdU(+) astrocytes, both of which were ameliorated by olomoucine. In the MCAO ischemia mouse model, dense reactive glial fibrillary acidic protein and PCNA immunoreactivity were evident at the boundary zone of focal cerebral ischemia at days 7 and 30 after MCAO. We found that intraperitoneal olomoucine administration significantly inhibited these astrogliosis‐associated changes. To demonstrate further that cell cycle regulation impacts on astrogliosis, cyclin D1 gene knockout mice (cyclin D1−/−) were subjected to ischemia, and we found that the percentage of Ki67‐positive astrocytes in these mice was markedly reduced in the boundary zone. The number of apoptotic neurons and the lesion volume in cyclin D1−/− mice also decreased as compared to cyclin D1+/+ and cyclin D1+/− mice at days 3, 7, and 30 after local cerebral ischemia. Together, these in vitro and in vivo results strongly suggest that astrogliosis can be significantly affected by cell cycle inhibition, which therefore emerges as a promising intervention to attenuate reactive glia‐related damage to neuronal function in brain pathology. © 2007 Wiley‐Liss, Inc.
Modifications of the fibroblast growth factor‐2 gene led to a marked enhancement in secretion and stability of the recombinant fibroblast growth factor‐2 protein
Authors: Chen Shin‐Tai , Gysin Reinhard , Kapur Sonia , Baylink David J. , William Lau K.‐H. 
Published: January 2007

AbstractProgress in FGF‐2 gene therapy has been hampered by the difficulty in achieving therapeutic levels of FGF‐2 secretion. This study tested whether the addition of BMP2/4 hybrid secretion signal to the FGF‐2 gene and mutation of cys‐70 and cys‐88 to serine and asparagine, respectively, would increase the stability and secretion of active FGF‐2 protein in mammalian cells using MLV‐based vectors. Single or double mutations of cys‐70 and cys‐88 to ser‐70 and asp‐88, respectively, markedly increased the amounts of FGF‐2 protein in conditioned media and cell lysates, which may be due to glycosylation, particularly at the mutated asp‐88 residue. Addition of BMP2/4 secretion signal increased FGF‐2 secretion, but also suppressed FGF‐2 biosynthesis. The combination of BMP2/4 secretion signal and double cys‐70 and cys‐88 mutations increased the total amount of secreted FGF‐2 protein >60‐fold. The modifications did not alter its ability to stimulate cell proliferation and Erk1/2 phosphorylation in marrow stromal cells or its ability to bind heparin in vitro, suggesting that the modified FGF‐2 protein was functionally as effective as the unmodified FGF‐2. An ex vivo application of rat skin fibroblasts (RSF) transduced with the modified FGF‐2 vector in a subcutaneous implant model showed that rats with implants containing cells transduced with the modified FGF‐2 vector increased serum FGF‐2 level >15‐fold, increased growth of the implant, and increased vascularization within the implant, compared to rats that received implants containing β‐galactosidase‐ or wild‐type FGF‐2‐transduced control cells. This modified vector may be useful in FGF‐2 gene therapy investigations. J. Cell. Biochem. 100: 1493–1508, 2007. © 2007 Wiley‐Liss, Inc.
Human Raf‐1 proteins associate with Rad24 and Cdc25 in cell‐cycle checkpoint pathway of fission yeast, Schizosaccharomyces pombe
Authors: Lee Michael , Yoo Hyang‐Sook 
Published: January 2007

AbstractRaf‐1 is a serine/threonine protein kinase that connects cell surface receptor signals to nuclear transcription factors. By screening Schizosaccharomyces pombe (S. pombe) cDNA library, we isolated Rad24, which is a 14‐3‐3 homolog that is important in the DNA damage checkpoint in S. pombe, as a Raf‐1 interacting protein. The interaction found in yeast was confirmed by co‐immunoprecipitation. Furthermore, Cdc25, which has been known to bind to Rad24, also associated with Raf‐1 and was phosphorylated in vitro by catalytically active Raf‐1. However, in the presence of Raf‐1, an interaction between Rad24 and Cdc25 was inhibited in triple hybrid assay, indicating that Raf‐1 inhibits the interaction between Rad24 and Cdc25. An in vitro competition assay showed that the binding of Cdc25 and of Rad24 to Raf‐1 is mutually exclusive. Western blots of whole cell lysates probed with polyclonal antibodies specific for tyrosine‐15‐phosphorylated Cdc2 showed that overproduction of Rad24 led to the dephosphorylation of tyrosine residue on Cdc2, which is known to be activated through dephosphorylation by Cdc25 phosphatase. Unexpectedly, overexpression of catalytically inactive mutant protein of Raf‐1, S624A, also caused tyrosine dephosphorylation of Cdc2. Thus, these data suggest that Raf‐1 may interfere with the role of Rad24 by competing with Rad24 for binding to Cdc25 or a direct phosphorylation of Cdc25, bypassing the checkpoint pathway in DNA repair through Cdc25 activation. J. Cell. Biochem. 101: 488–497, 2007. © 2007 Wiley‐Liss, Inc.
Identification of mechanosensitive genes in osteoblasts by comparative microarray studies using the rotating wall vessel and the random positioning machine
Authors: Patel Mamta J. , Liu Wenbin , Sykes Michelle C. , Ward Nancy E. , Risin Semyon A. , Risin Diana , Jo Hanjoong 
Published: January 2007

AbstractWeightlessness or microgravity of spaceflight induces bone loss due in part to decreased bone formation by unknown mechanisms. Due to difficulty in performing experiments in space, several ground‐based simulators such as the Rotating Wall Vessel (RWV) and Random Positioning Machine (RPM) have become critical venues to continue studying space biology. However, these simulators have not been systematically compared to each other or to mechanical stimulating models. Here, we hypothesized that exposure to RWV inhibits differentiation and alters gene expression profiles of 2T3 cells, and a subset of these mechanosensitive genes behaves in a manner consistent to the RPM and opposite to the trends incurred by mechanical stimulation of mouse tibiae. Exposure of 2T3 preosteoblast cells to the RWV for 3 days inhibited alkaline phosphatase activity, a marker of differentiation, and downregulated 61 and upregulated 45 genes by more than twofold compared to static 1 g controls, as shown by microarray analysis. The microarray results were confirmed by real‐time PCR and/or Western blots for seven separate genes and proteins includingosteomodulin,runx2, andosteoglycin. Comparison of the RWV data to the RPM microarray study that we previously published showed 14 mechanosensitive genes that changed in the same direction. Further comparison of the RWV and RPM results to microarray data from mechanically loaded mouse tibiae reported by an independent group revealed that three genes includingosteoglycinwere upregulated by the loading and downregulated by our simulators. These mechanosensitive genes may provide novel insights into understanding the mechanisms regulating bone formation and potential targets for countermeasures against decreased bone formation during space flight and in pathologies associated with lack of bone formation. J. Cell. Biochem. 101: 587–599, 2007. © 2007 Wiley‐Liss, Inc.
Cisplatin cytotoxicity in organ of corti‐derived immortalized cells
Authors: Previati Maurizio , Lanzoni Irene , Astolfi Laura , Fagioli Francesco , Vecchiati Giorgio , Pagnoni Antonella , Martini Alessandro , Capitani Silvano 
Published: January 2007

AbstractCisplatin is an anticancer drug currently used in the treatment of genital and head and neck tumors. Its use in these and other types of tumors is narrowed by onset of chemoresistance and severe undesired side effects, like as nephro‐ and ototoxicity, whose mechanisms of action are only partially understood. In the present study we investigated the effects of cisplatin (cis‐dichlorodiaminoplatin, CDDP) on a cell line (OC‐k3) developed from organs of Corti of transgenic mice. We observed at 48 h that cell death due to cisplatin was time and concentration‐dependent. The cell death displayed some morphological hallmarks of apoptosis, including nuclear fragmentation into several large nuclear fragments, surrounded by a rearranged and thickened actin cytoskeleton. No DNA laddering was detected, suggesting absence of endonuclease activity, nor annexin V positivity, suggesting absence of phosphatidylserine externalization. Several molecules protected the cells against CDDP induced cytotoxicity, including methionine, suramin and PD98059. Methionine reduced CDDP‐uptake, while suramin, a polycathionic compound a specifically binding external proteins, did not. This finding suggested that suramin could exert its protective effect by acting on an intracellular transduction pathway. We tested this hypothesis by studying the effect of suramin and PD98059, a MEK inhibitor, on the mitogen activated protein kinase (MAPK) cascade. After CDDP treatment, we found an increase of phosphorylation of extracellular regulated kinases (ERK)1/2, that could be inhibited by PD98059 and suramin. These data suggest that ERK pathways can play a role in mediating the cell death induction in presence of a CDDP challenge. J. Cell. Biochem. 101:1185–1197, 2007. © 2007 Wiley‐Liss, Inc.
Easy preparative scale syntheses of labelled xanthines: caffeine, theophylline and theobromine
Authors: Balssa Frédéric , Bonnaire Yves 
Published: January 2007

AbstractSeveral easy preparative scale (0.5–1.5 g) syntheses of deuterium labelled caffeine, theophylline and theobromine are described. Some new selective syntheses of theophylline and theobromine have been developed. Labelled xanthines are of great interest in qualitative or quantitative isotope dilution‐mass spectrometry, coupled with gas or liquid chromatography, currently performed in anti‐doping and forensic laboratories. Copyright © 2007 John Wiley & Sons, Ltd.