bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pattern analysis of serum proteome distinguishes renal cell carcinoma from other urologic diseases and healthy persons
Authors: Won Yonggwan , Song Ho‐Jun , Kang Taek Won , Kim Jung‐Ja , Han Byoung‐Don , Lee Seung‐won 
Published: December 2003

AbstractDespite having a relatively low incidence, renal cell carcinoma (RCC) is one of the most lethal urologic cancers. For successful treatment including surgery, early detection is essential. Currently there is no screening method such as biomarker assays for early diagnosis of RCC. Surface‐enhanced laser desorption/ionization‐time of flight mass spectrometry (SELDI‐TOF) is a recent technical advance that can be used to identify biomarkers for cancers. In this study, we investigated whether SELDI protein profiling and artificial intelligence analysis of serum could distinguish RCC from healthy persons and other urologic diseases (nonRCC). The SELDI‐TOF data was acquired from a total of 36 serum samples with weak cation exchange‐2 protein chip arrays and filtered using ProteinChip software. We used a decision tree algorithm c4.5 to classify the three groups of sera. Five proteins were identified with masses of 3900, 4107, 4153, 5352, and 5987 Da. These biomarkers can correctly separate RCC from healthy and nonRCC samples.
Monitoring protein expression by proteomics: Human plasma exposed to benzene
Authors: Joo Won‐A , Kang Mee‐Jeong , Son Won‐kyu , Lee Hyun‐Ju , Lee Do‐Youn , Lee Eunil , Kim Chan‐Wha 
Published: December 2003

AbstractLow levels and long term exposure to benzene is associated with hematotoxicity including aplastic anemia, acute myelogenous leukemia, and lymphoma. Current biomonitoring methods such as urinary phenol, S‐phenylmercapturic acid, and trans‐trans muconic acid were found to be unreliable as analytical methods to detect benzene exposure. Therefore, to search for a specific protein for biomonitoring benzene exposure, we investigated plasma proteins from workers (n = 50) at a printing company who were exposed to benzene, by two‐dimensional gel electrophoresis. The protein profiles are significantly different (p 〈 0.05) between benzene exposed and unexposed groups, as identified by matrix‐assisted laser desorption ionization/time of flight mass spectrometry and confirmed by Western blot analyses. T cell receptor β chain (TCR β), FK506‐binding protein, and matrix metalloproteinase‐13 were expressed only in benzene exposed workers. In addition, interleukin‐4 receptor α chain and T cell surface glycoprotein CD1b precursor were found to be up‐regulated in the plasma of benzene exposed workers. When we treated Jurkat cells with benzene (10 μM–10 mM), TCR β expression was increased in the membrane more than 6–9‐fold compared to untreated cells. In addition, the amount of TCR β released into the culture media, at benzene concentrations greater than 50 μM, increased up to 10 mM. Therefore, TCR β levels in plasma could be used as a biomarker and a possible therapeutic target for benzene exposure.
Establishment of a two‐dimensional electrophoresis map forNeospora caninumtachyzoites by proteomics
Authors: Lee Eung Goo , Kim Jae Hoon , Shin Yong Seung , Shin Gee Wook , Suh Myung Deuk , Kim Dae Yong , Kim Yong Hwan , Kim Gon Sup , Jung Tae Sung 
Published: December 2003

AbstractExpressed proteins and antigens fromNeospora caninumtachyzoites were studied by two‐dimensional gel electrophoresis and immunoblot analysis combined with matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry. Thirty‐one spots corresponding to 20 different proteins were identified fromN. caninumtachyzoites by peptide mass fingerprinting. Six proteins were identified from aN. caninumdatabase (NTPase, 14‐3‐3 protein homologue, NcMIC1, NCDG1, NcGRA1 and NcGRA2), and 11 proteins were identified in closely related species using theT. gondiidatabase (HSP70, HSP60, pyruvate kinase, tubulin α‐ and β‐chain, putative protein disulfide isomerase, enolase, actin, fructose‐1,6‐bisphosphatase, lactate dehydrogenase and glyceradehyde‐3‐phosphate dehydrogenase). One hundred and two antigen spots were observed using pH 4–7 IPG strips on immunoblot profiles. Among them, 17 spots corresponding to 11 antigenic proteins were identified from aN. caninumprotein map. This study involved the construction of in‐depth protein maps forN. caninumtachyzoites, which will be of value for studies of its pathogenesis, drug and vaccine development, and phylogenetic studies.
Characterization of a bovine pregnancy‐associated protein using two‐dimensional gel electrophoresis, N‐terminal sequencing and mass spectrometry
Authors: Pyo Jaehoon , Hwang Sun‐Il , Oh Jisun , Lee So‐Jin , Kang Sun‐Cheol , Kim Jong‐Sang , Lim Jinkyu 
Published: December 2003

AbstractBovine pregnancy‐associated protein (bPAP) isolated from pregnant bovine urines by two‐dimensional electrophoresis (2‐DE) was characterized by N‐terminal sequencing, internal sequencing, and mass spectrometric analyses using matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry and tandem mass spectrometry. Database search using the amino acid sequences and the peptide mass profiles showed that the protein is a novel bovine pregnancy‐associated protein of which the N‐terminus has a high similarity to collagen alpha. The protein has a molecular mass of 21 kDa and a pI of 6.1. The expression profiles of the protein from the urine of 30 pregnant and 20 nonpregnant cows characterized by 2‐DE indicated that the expression of bPAP during pregnancy increased to over nmol from the pmol level basal expression of bPAP at the nonpregnant state with < 3% of false negatives and < 10% of false positives. Using the peptide sequence information, polyclonal antibodies against the bPAP protein were generated. The purified polyclonal antibodies against the peptide sequences of bPAP detected the 21 kDa protein on the blots of pregnant cow urine by Western blot analysis. In addition, analysis showed that the expression of bPAP in the urine is associated with pregnancy, but that the urine concentration of bPAP is not correlated with the duration of the pregnancy.
Proteome analysis of hairy root from Panax ginseng C. A. Meyer using peptide fingerprinting, internal sequencing and expressed sequence tag data
Authors: Kim Seung Il , Kim Jin Young , Kim Eun A. , Kwon Kyung‐Hoon , Kim Kyung‐Wook , Cho Kun , Lee Jeong Hwa , Nam Myung Hee , Yang Deok‐Chun , Yoo Jong Shin , Park Young Mok 
Published: December 2003

AbstractAs an initial step to the comprehensive proteomic analysis of Panax ginseng C. A. Meyer, protein mixtures extracted from the cultured hairy root of Panax ginseng were separated by two‐dimensional polyacrylamide gel electrophoresis (2‐DE). The protein spots were analyzed and identified by peptide finger printing and internal amino acid sequencing by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry (MALDI‐TOF MS) and electrospray ionization quadrupole‐time of flight mass spectrometry (ESI Q‐TOF MS), respectively. More than 300 protein spots were detected on silver stained two‐dimensional (2‐D) gels using pH 3–10, 4–7, and 4.5–5.5 gradients. Major protein spots (159) were analyzed by peptide fingerprinting or de novo sequencing and the functions of 91 of these proteins were identified. Protein identification was achieved using the expressed sequence tag (EST) database from Panax ginseng and the protein database of plants like Arabidopsis thaliana and Oryza sativa. However, peptide mass fingerprinting by MALDI‐TOF MS alone was insufficient for protein identification because of the lack of a genome database for Panax ginseng. Only 17 of the 159 protein spots were verified by peptide mass fingerprinting using MALDI‐TOF MS whereas 87 out of 102 protein spots, which included 13 of the 17 proteins identified by MALDI‐TOF MS, were identified by internal amino acid sequencing using tandem mass spectrometry analysis by ESI Q‐TOF MS. When the internal amino acid sequences were used as identification markers, the identification rate exceeded 85.3%, suggesting that a combination of internal sequencing and EST data analysis was an efficient identification method for proteome analysis of plants having incomplete genome data like ginseng. The 2‐D patterns of the main root and leaves of Panax ginseng differed from that of the cultured hairy root, suggesting that some proteins are exclusively expressed by different tissues for specific cellular functions. Proteome analysis will undoubtedly be helpful for understanding the physiology of Panax ginseng.
Synthesis and characterization of new segmented polyurethanes with side‐chain, liquid‐crystalline chain extenders
Authors: Huang Fang‐Jung , Wang Tzong‐Liu 
Published: December 2003

AbstractLiquid‐crystalline, segmented polyurethanes with methoxy–biphenyl mesogens pendant on the chain extender were synthesized by the conventional prepolymer technique and esterification reaction. Two, side‐chain, liquid‐crystalline (SCLC) polyurethanes with mesogens having spacers of six and eight methylene units were prepared. The structures of the mesogenic units and SCLC polyurethanes were confirmed by Fourier transform infrared spectroscopy and 1H NMR. Polymer properties were also examined by solubility tests, water uptakes, and inherent viscosity measurements. Differential scanning calorimetry studies indicated that the transition temperature of the isotropic to the liquid‐crystalline phase decreased with increasing spacer length. Wide‐angle X‐ray diffraction (WAXD) studies revealed the existence of liquid‐crystalline phases for both SCLC polyurethanes. Polarized optical microscopic investigations further confirmed the thermotropic liquid‐crystalline behaviors and nematic mesophases of both samples. Thermogravimetric analysis displayed better thermal stabilities for both SCLC polymers and indicated that the presence of mesogenic side chains may increase the thermal stability of segmented polyurethanes. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 290–302, 2004
Thermoplastic poly(ester‐imide)s derived from anhydride‐terminated polyester prepolymer and diisocyanate
Authors: Banu P. , Radhakrishnan Ganga 
Published: December 2003

AbstractThe phase‐separation behavior of thermoplastic poly(ester‐imide) [P(E‐I)] multiblock copolymers, (A‐B)n, was investigated by a stepwise variation of the imide content. All the multiblock copolymers were synthesized by solution polycondensation with dimethylformamide as a solvent. P(E‐I)s were prepared with anhydride‐terminated polyester prepolymer and diisocyanates. Polyester prepolymers were prepared by the reaction of pyromellitic dianhydride and two different polyols [poly(tetramethylene oxide glycol) (PTMG) and polycaprolactone diol (PCL)]. Structural determination was done with Fourier transform infrared spectroscopy and Fourier transform NMR, and the molecular weight was determined by gel permeation chromatography. The effect of the imide content on the thermal properties of the synthesized P(E‐I)s was investigated by thermogravimetric analysis and differential scanning calorimetry. The polymers were also characterized for static and dynamic mechanical properties. Thermal analysis data indicated that the polymers based on PTMG were stable up to 330 °C in nitrogen atmosphere and exhibited phase‐separated morphology. Polymers based on PCL showed multistage decomposition, and the films derived from them were too fragile to be characterized for static and dynamic mechanical properties. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 341–350, 2004
Mechanism of the anionic polymerization of methyl methacrylate initiated by tetramethylammonium–triphenylmethide in tetrahydrofuran
Authors: Warner William N. , Hu Jinbo , Surya Prakash G. K. , Olah George A. , Hogen‐Esch Thieo E. 
Published: December 2003

AbstractA tetramethylammonium (TMA)–triphenylmethide (TPM) initiator generated in situ by the reaction of trimethyltriphenylmethylsilane with tetramethylammonium fluoride in tetrahydrofuran was found to have greater stability than the corresponding tetrabutylammonium or tetrahexylammonium derivatives. The predominant mode of degradation of TMA–TPM was found to be the TMA‐mediated methylation of TPM anions. The initiation of methyl methacrylate by TMA–TPM in tetrahydrofuran at −78 °C was demonstrated to produce quantitative yields of poly(methyl methacrylate) with polydispersities of less than 1.1. Although the initiator efficiencies were low (9–40%) because of relatively slow initiation on the polymerization timescale, the initiation appeared to be rapid enough to give relatively narrow molecular weight distributions. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 237–244, 2004
Synthesis of random terpolymers and determination of reactivity ratios of N‐carboxyanhydrides of leucine, β‐benzyl aspartate, and valine
Authors: Wamsley Andrea , Jasti Bhaskara , Phiasivongsa Pasit , Li Xiaoling 
Published: December 2003

AbstractThe copolymerization and terpolymerization of leucine‐N‐carboxyanhydride, β‐benzyl aspartate‐ N‐carboxyanhydride, and valine‐N‐carboxyanhydride in dioxane, initiated with triethylamine, were investigated to determine the random nature of the terpolymer composition for potential applications as targeting drug delivery carriers. 1H NMR was used to obtain the actual monomer compositions of the polymers. The reactivity ratio of each monomer was determined with Fineman–Ross, Kelen–Tüdös, and nonlinear least‐squares curve‐ fitting methods. The product of the estimated reactivity ratios from the monomers in the binary copolymerizations indicated that random polymers were predominantly formed. On the basis of the reactivity ratios determined from the binary copolymers, Alfrey–Goldfinger equations were used to estimate the compositions of the terpolymers. There was no statistical difference between the actual monomer compositions and the calculated compositions of the terpolymers; this validated the reactivity ratios estimated by Fineman–Ross, Kelen–Tüdös, and nonlinear least‐squares curve‐ fitting methods. Therefore, the poly(leucine‐β‐Bzl‐ aspartate‐valine) synthesized in this study was primarily a random terpolymer. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 317–325, 2004
Poly[(2‐alkoxy‐5‐methyl‐1,3‐phenylene vinylene)‐alt‐(phenylene vinylene)] derivatives with different contents ofcis‐ andtrans‐olefins: The effect of the olefin bond geometry and conjugation length on luminescence
Authors: Liao Liang , Ding Liming , Karasz Frank E. , Pang Yi 
Published: December 2003

AbstractPoly[(2‐alkyloxy‐5‐methyl‐1,3‐phenylenevinylene)‐alt‐(1,3‐phenylenevinylene)]s (8) and poly[(2‐alkyloxy‐5‐methyl‐1,3‐phenylenevinylene)‐alt‐(1,4‐phenylenevinylene)]s (10) were synthesized by the Wittig reaction to provide materials containing 45–62%cis‐vinylene bonds. The optical characteristics of8and10were compared with those of their respective isomers,3and4, thecis‐vinylene contents of which were significantly lower (9–16%). Although a greater fraction ofcis‐CHCH linkages caused the absorption maximum (λmax) of8and10to be slightly blueshifted (by ∼3–6 nm) from that of3and4, the impact of the vinylene bond geometry appeared to be negligible on their fluorescence spectra. The fluorescence quantum efficiencies of8and10were estimated to be approximately 0.25 and 0.72, respectively. Both8(λmax≈ 445 or 462 nm) and10(λmax≈ 480 or 506 nm) were electroluminescent, showing effective color tuning by the controlled insertion ofm‐phenylene moieties. The external electroluminescence quantum efficiencies were determined to be 4.26 × 10−3% for8and 0.63% for10. Thecis/trans‐vinylene bond ratio had a great impact on the electroluminescence device performance of8but a much smaller impact on the performance of10. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 303–316, 2004
Diffusion and partition coefficients of small organic solvents in molten miscible polymer blends: Correlations with thermodynamic interactions
Authors: Popovska‐Pavlovska F. , Raka Lj. 
Published: December 2003

AbstractThe transport properties of small organic molecules in molten poly(vinyl chloride) (PVC)/atactic poly(methyl methacrylate) (PMMA) blends and their homopolymers were studied with inverse gas chromatography. The elution profiles resulting from various organic solvents and different experimental conditions were used for measuring diffusion and partition coefficients. With the van Deemter equation and retention volumes at infinite dilution, diffusion coefficients of 10−7 to 10−8 cm2/s and partition coefficients of 10–50 were calculated. The dependence of the diffusion and partition coefficients on experimental variables such as the blend concentration, temperature, and solute nature was examined. The presence of PMMA in PVC blends affected the sorption behavior of the PVC matrix up to a certain concentration. Beyond that, it was hard to derive any composition–diffusivity dependence. On the contrary, the diffusion and partition coefficients were greatly influenced by changes in the temperature and by the nature of the solute. For those solutes (e.g., chlorinated hydrocarbons) showing stronger interactions with polymer blends (higher negative values for the Flory–Huggins interaction parameter χ1(23)), higher diffusion and partition coefficients were obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 267–279, 2004
Morphology and fracture behavior of toughening‐modified poly(vinyl chloride)/organophilic montmorillonite composites
Authors: Wan Chao Ying , Zhang Yong , Zhang Yin Xi , Qiao Xiu Ying , Teng Guo Min 
Published: December 2003

AbstractToughening‐modified poly(vinyl chloride) (PVC)/organophilic montmorillonite (OMMT) composites with an impact‐modifier resin (Blendex 338) were prepared by melt intercalation, and their microstructures were investigated with wide‐angle X‐ray diffraction, transmission electron microscopy, and scanning electron microscopy. The mechanical properties of the PVC composites were examined in terms of the content of Blendex and OMMT, and the fracture toughness was analyzed with a modified essential work of fracture model. Intercalated structures were found in the PVC/OMMT composites with or without Blendex. Either Blendex or OMMT could improve the elongation at break and notched impact strength of PVC at proper contents. With the addition of 30 phr or more of Blendex, supertough behavior was observed for PVC/Blendex blends, and their notched impact strength was increased more than 3319% compared with that of pristine PVC. Furthermore, the addition of OMMT greatly improved both the toughness and strength of PVC/Blendex blends, and the toughening effect of OMMT on PVC/Blendex blends was much larger than that on pristine PVC. Blendex and OMMT synergistically improved the mechanical properties of PVC. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 286–295, 2004
Phonon dispersion in poly(L‐tryptophan)
Authors: Pande Sapna , Tandon Poonam , Gupta V.D. 
Published: December 2003

AbstractThe normal modes and their dispersions for poly(L‐tryptophan) (PLTR) in the α‐helical form have been obtained in a reduced zone scheme with Wilson's GF matrix method as modified by Higgs. Dynamic studies of the α form are of special significance as it is the predominant secondary structure for protein molecules. X‐ray and circular dichroism (CD) studies by Peggion et al. have confirmed the α‐helical conformation of PLTR. The side group of PLTR is more complicated than that of other natural polypeptides. It consists of both a pyrrole and a benzene ring along with a CH2 group. Optically active frequencies corresponding to the zone center and zone boundary are identified and discussed. Some of the characteristic features of the dispersion curves are repulsion accompanied by an exchange of character and von Hove singularities. The heat capacity has been calculated via densities of state with Debye's equation in the temperature range of 220–390 K and has been compared with experimental measurements. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 316–332, 2004
Influence of additives on the crystal structure and melting behavior of poly(ethylene‐2,6‐naphthalene dicarboxylate)
Authors: Gao Xia , Liu Ruigang , Yu Yin , Jin Manna , Bu Haishan 
Published: December 2003

AbstractThe influence of additives on the crystal modification and melting behavior of poly(ethylene‐2,6‐naphthalene dicarboxylate) (PEN) was investigated with wide‐angle X‐ray diffraction and differential scanning calorimetry (DSC). The addition of a nucleating promoter, Ceraflour 993, had no effect on the crystal modification and melting behavior of PEN crystallized under all chosen experimental conditions. However, the addition of a nucleating agent, sodium benzoate (SB), did affect the crystal modification and melting behavior of PEN when PEN/SB was crystallized at a higher temperature, but not at a lower temperature. A mixture of α and β modifications of PEN was obtained, and an overlapped dual melting peak was observed in DSC curves when PEN was crystallized at a higher temperature in the presence of SB, instead of a single crystal form and a single melting peak for the crystallization of pure PEN. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 296–301, 2004
Structural changes of silver polymer electrolytes: Comparison between poly(2‐ethyl‐2‐oxazoline) and poly(N‐vinyl pyrrolidone) complexes with silver salt
Authors: Hak Kim Jong , Ryul Min Byoung , Kon Kim Chang , Won Jongok , Soo Kang Yong 
Published: December 2003

AbstractThe difference between the polymer matrices of poly(2‐ethyl‐2‐oxazoline) (POZ) and poly(N‐vinyl pyrrolidone) (PVP) does not have a significant effect on the facilitated propylene transport and propylene solubility in 1:1 polymer/silver salt complex membranes, according to our previous work. In this article, its origin is investigated in terms of both microstructures of silver polymer electrolytes and the coordinative interaction of silver ion with polymer and with the counteranion. Initially different microstructures of POZ and PVP become similar to each other upon dissolving a large amount of silver salt, as evidenced by propane transport properties, specific volume, and Bragg d‐spacing. The dissolution of the silver salt in the polymer solvent strongly depends on the coordinative interaction between silver ion and carbonyl oxygen of POZ and PVP. Thus, the structural similarity upon dissolving silver salts in POZ and PVP is primarily determined by the coordinative interaction between silver ion and carbonyl oxygen, which was confirmed by theoretical structure calculation based on density functional theory and by IR and Raman spectroscopy. Therefore, facilitated olefin transport for silver polymer electrolyte membranes does not strongly depend on the polymeric matrix at high silver concentrations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 232–237, 2004
Polymorphism in nylon‐11/montmorillonite nanocomposite
Authors: Zhang Guosheng , Li Yongjin , Yan Deyue 
Published: December 2003

AbstractThe polymorphism behavior in nylon‐11/montmorillonite (MMT) nanocomposite was investigated by wide‐angle X‐ray diffraction (WAXD) and variable‐temperature infrared spectroscopy. The results of WAXD and IR confirmed the presence of the γ‐crystalline form of nylon‐11, which is induced and stabilized by MMT. However, the hydrogen bond in the nanocomposite and its temperature dependence also exhibited some differences from neat nylon‐11. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 253–259, 2004