bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors influencing the small‐scale melt spinning of poly(ε‐caprolactone) monofilament fibres
Authors: Charuchinda Anodar , Molloy Robert , Siripitayananon Jintana , Molloy Nipapan , Sriyai Montira 
Published: June 2003

AbstractSome of the main factors affecting the small‐scale melt spinning of poly(ε‐caprolactone), PCL, monofilament fibres have been studied. These factors included spinning temperature, extrusion rate, take‐up rate and draw ratio. The underlying influence of the polymer's own characteristic properties, in particular its chemical structure, transition temperatures (Tg, Tm) and crystallizability, were also interpreted within the context of the melt spinning process. Physically, the as‐spun fibres obtained were uniform in diameter and smooth in surface appearance. They were also semi‐crystalline (>50%) in morphology. Mechanically, however, they were still very weak and highly extensible. Subsequent off‐line cold‐drawing at room temperature introduced the required degree of molecular orientation to reinforce the fibres, yielding tensile strengths of approaching 300 MPa. PCL fibres of precisely controlled physical dimensions and matrix morphology are attracting increasing interest for use in biomedical applications. This paper describes how this control can be achieved through the processing operation. Copyright © 2003 Society of Chemical Industry
Morphology and rheological properties of nanocomposites based on nitrile rubber and organophilic layered silicates
Authors: Kim Jin‐tae , Oh Taeg‐su , Lee Dong‐ho 
Published: June 2003

AbstractOrgano‐montmorillonite/nitrile rubber (NBR) nanocomposites were prepared by a melt intercalation process. The characteristics of NBR nanocomposites were determined by an oscillating disk rheometer and transmission electron microscopy. The cure characteristics were investigated according to the change in clay content and clay types. This study confirmed that organo‐montmorillonite/NBR nanocomposites have various cure characteristics, namely minimum torque, maximum torque, scorch time and curing time, according to the change in clay content and clay types. In particular, as the chain length of the modifier used for the treatment of Na+‐MMT following vulcanization increases, scorch time and optimum curing time are reduced. This is because, as the chain length of the modifier increases, organo‐MMT is distributed more equally during the formation of the nanocomposites. As swelling increases, the chain length of the clay modifier expands and then constitutes a better barrier. Copyright © 2003 Society of Chemical Industry
Synthesis and characterisation of branched and partially crosslinked poly(ethylene terephthalate)
Authors: Bikiaris DN , Karayannidis GP 
Published: June 2003

AbstractIn the present study, a series of branched and partially crosslinked poly(ethylene terephthalate) (PET) samples were prepared by the two‐stage melt polycondensation method, using different amounts of trimethyl trimellitate (TMT) as polyfunctional monomer. The samples were characterised with respect to intrinsic viscosity, density and gel content as well as thermal and mechanical properties. The intrinsic viscosity of the polymers ranged between 0.7 and 1.6 dl g−1 depending on the concentration of the TMT comonomer. When TMT was used at a concentration 0.625 wt% or higher, gel formation was observed. For the sample containing 1.25 wt% TMT, almost half of the polymer was insoluble in phenol–tetrachloroethane mixture, due to extensive crosslinking. The increase of TMT content resulted in a small decrease of crystallinity attributed to branching and crosslinking, both of which restrict the organisation of the polymer chains in the crystal structure. This was reflected directly in the thermal properties of the polymers prepared. Increasing the TMT content decreased the melting point and the heat of fusion. In contrast, cold crystallization and glass transition temperatures were shifted to higher temperatures. Mechanical properties like tensile strength and elongation at break increased with increasing the content in branching agent. However, crosslinking had a negative effect on elongation at break. Copyright © 2003 Society of Chemical Industry
Analysis of rat testicular protein expression following 91‐day exposure to JP‐8 jet fuel vapor
Authors: Witzmann Frank A. , Bobb Andrew , Briggs G. Bruce , Coppage Heather N. , Hess Rex A. , Li Junyu , Pedrick Nathan M. , Ritchie Glenn D. , III John Rossi , Still Kenneth R. 
Published: June 2003

AbstractWe analyzed protein expression in preparations from whole testis in adult male Sprague‐Dawley rats exposed for 6 h/d for 91 consecutive days to jet propulsion fuel‐8 (JP‐8) in the vapor phase (0, 250, 500, or 1000 mg/m3 ± 10%), simulating a range of possible human occupational exposures. Whole body inhalation exposures were carefully controlled to eliminate aerosol phase, and subjects were sacrificed within 48 h postexposure. Organ fractions were solubilized and separated via large‐scale, high resolution two‐dimensional electrophoresis, and gel patterns scanned, digitized and processed for statistical analysis. Seventy‐six different testis proteins were significantly increased or decreased in abundance in vapor‐exposed groups, compared to controls, and dose‐response profiles were often nonlinear. A number of the proteins were identified by peptide mass fingerprinting and related to histopathological or physiological deficits shown in previously published studies to occur with repeated exposure to hydrocarbon fuels or solvents. These results demonstrate a significant effect of JP‐8 exposure on protein expression, particularly in protein expression in the rodent testis, and suggest that a 91 d exposure to jet fuel vapor induces changes of equal or greater magnitude to those reported previously for shorter duration JP‐8 aerosol exposures.
Proteome analysis of dermal fibroblasts cultured in vitro from human healthy subjects of different ages
Authors: Boraldi Frederica , Bini Luca , Liberatori Sabrina , Armini Allessandro , Pallini Vitaliano , Tiozzo Roberta , Pasquali‐Ronchetti Ivonne , Quaglino Daniela 
Published: June 2003

AbstractAging is a complex multifactorial process still far from being completely understood. The aim of the present study was to compare the proteome of in vitro cultured dermal fibroblasts from healthy subjects of different ages (i.e. 15 ± 2, 41 ± 4 and 82 ± 3 years old). Proteins of the cell layer were separated by two‐dimensional electrophoresis and protein identification was performed by matrix‐assisted laser desorption/ionization‐time of flight mass spectrometry; moreover, synthetic gels were qualitatively and quantitatively analyzed by Melanie 3 software. Our study did not reveal any protein typical of any one age group. On the other hand, we observed 38 proteins exhibiting more than three‐fold reproducible variations with aging, some (45%) being reduced such as F‐actin capping protein α1, proteasome subunit alpha type 3, heat shock protein 27, ubiquitin carboxyl‐terminal hydrolase isozyme L1, mitochondrial thioredoxin‐dependent peroxide reductase, cathepsin B, glutathione S‐transferase P, cyclophilin A and calgizzarin. In contrast, T‐complex protein 1, probable protein disulfide isomerase ER60, phosphoglycerate kinase 1, Ran‐specific GTPase‐activating protein, proteasome subunit alpha type 5, triosephosphate isomerase and superoxide dismutase (Mn) increased with age. Furthermore, annexin 1, elongation factor 1β, proteasome activator complex subunit 1, phosphoglycerate mutase, superoxide dismutase (Cu‐Zn) and cofilin, exhibited the highest levels in adult cells; whereas, septin 2 homolog, RNA‐binding protein regulatory subunit and ATP synthase D chain revealed the lowest values in adults. The present investigation, underlining the complexity of the aging process, highlights the role of synthetic and degradative pathways in modulating the whole cell machinery and emphasizes that metabolic impairment with age could depend partly on different expression of a number of genes and leading to an imbalance among functional proteins.
Proteomic analysis of human vessels: Application to atherosclerotic plaques
Authors: Duran Mari Carmen , Mas Sebastian , Martin‐Ventura Jose Luis , Meilhac Olivier , Michel Jean Baptiste , Gallego‐Delgado Julio , Lázaro Alberto , Tuñon José , Egido Jesus , Vivanco Fernando 
Published: June 2003

AbstractAtherosclerosis is a chronic disease that affects medium and large arteries. This process originates from the interaction between cells of the arterial wall, lipoproteins and inflammatory cells, leading to the development of complex lesions or plaques that protrude into the arterial lumen. Plaque rupture and thrombosis result in acute clinical complications such as myocardial infarction and stroke. Owing to the heterogeneous cellular composition of the plaques, a proteomic analysis of the whole lesion is not appropriate. Therefore, we have studied the proteins secreted by human carotid atherosclerotic plaques, obtained by endarterectomy. Normal artery segments and different regions of the surgical pieces (noncomplicated plaque, complicated plaque with thrombus) were cultured in protein‐free medium and the secreted proteins (supernatants) analyzed by two‐dimensional gel electrophoresis. Normal artery segments secreted a moderate number of proteins (42 spots). However in the two‐dimensional (2‐D) gels (pH 3–10) of segments bearing a plaque, the number of spots increased markedly (154). The number of spots also increased (202) in the 2‐D gels of artery segments with a ruptured plaque and thrombus. Thus, the more complicated the lesion, the higher the number of secreted proteins, suggesting the production of specific proteins relating to the complexity of the atherosclerotic lesion.
Detection of protein‐protein interactions and a group of immunoglobulin G‐associated minor proteins in human plasma by nondenaturing and denaturing two‐dimensional gel electrophoresis
Authors: Manabe Takashi , Yamaguchi Nao , Mukai Jun , Hamada Osamu , Tani Osamu 
Published: June 2003

AbstractThe dissociation of noncovalently associated protein‐protein complexes in human plasma was examined by comparing two‐dimensional gel electrophoresis (2‐DE) patterns obtained in two different electrophoretic conditions. A type I 2‐DE pattern was obtained running nondenaturing isoelectric focusing (IEF) followed by nondenaturing gel electrophoresis and a type II 2‐DE pattern was nondenaturing IEF followed by sodium dodecyl sulfate gel electrophoresis. Micro‐sized gels (internal diameter(id) 1.3×35 mm polyacrylamide IEF gels and 38×38×1 mm polyacryamide slab gels) were used to follow the dissociation processes of major plasma proteins. Larger gel sizes (id 3.4×160 mm agarose IEF gels and 160×120×2.8 mm polyacrylamide slab gels) were used to detect minor plasma proteins dissociated from major proteins. About 110 spots, which have not been detected on type I (nondenaturing) 2‐D gels, newly appeared on type II large‐sized 2‐D gels at molecular masses smaller than 67 kDa. Some of these spots had been analyzed and identified, but about 70 minor spots (isoelectric point 5.5–7.5 and relative molecular mass 8–45 kDa) were detected for the first time by applying large volumes of human plasma samples to the large type II 2‐D gels. These minor spots could be concentrated on type II 2‐D gels by enriching the immunoglobulin G (IgG) fraction under nondenaturing conditions, and they disappeared when IgG was removed from the fraction. These results strongly suggest that many of the minor spots newly detected were bound to IgG in physiological conditions.
Identification of markers for the selection of patients undergoing renal cell carcinoma‐specific immunotherapy
Authors: Seliger Barbara , Menig Matthias , Lichtenfels Rudolf , Atkins Derek , Bukur Jürgen , Halder Thomas M. , Kersten Michael , Harder Alois , Ackermann Angelika , Beck Joachim , Muehlenweg Bernd , Brenner Walburgis , Melchior Sebastian , Kellner Roland , Lottspeich Friedrich 
Published: June 2003

AbstractRenal cell carcinoma (RCC) represents the most common malignant tumor in the kidney and is resistant to conventional therapies. The diagnosis of RCC is often delayed leading to progression and metastatic spread of the disease. Thus, validated markers for the early detection of the disease as well as selection of patients undergoing specific therapy is urgently needed. Using treatment with the monoclonal antibody (mAb) G250 as a model, proteome‐based strategies were implemented for the identification of markers which may allow the discrimination between responders and nonresponders prior to application of G250‐mediated immunotherapy. Flow cytometry revealed G250 surface expression in approximately 40% of RCC cell lines, but not in the normal kidney epithelium cell lines. G250 expression levels significantly varied thereby distinguishing between low, medium and high G250 expressing cell lines. Comparisons of two‐dimensional gel electrophoresis expression profiles of untreated RCC cell lines versus RCC cell lines treated with a mAb directed against G250 and the characterization of differentially expressed proteins by mass spectrometry and/or Edman sequencing led to the identification of proteins such as chaperones, antigen processing components, transporters, metabolic enzymes, cytoskeletal proteins and unknown proteins. Moreover, some of these differentially expressed proteins matched with immunoreactive proteins previously identified by proteome analysis combined with immunoblotting using sera from healthy donors and RCC patients, a technique called PROTEOMEX. Immunohistochemical analysis of a panel of surgically removed RCC lesions and corresponding normal kidney epithelium confirmed the heterogeneous expression pattern found by proteome‐based technologies. In conclusion, conventional proteome analysis as well as PROTEOMEX could be successfully employed for the identification of markers which may allow the selection of patients prior to specific immunotherapy.
From transcriptome to proteome: Differentially expressed proteins identified in synovial tissue of patients suffering from rheumatoid arthritis and osteoarthritis by an initial screen with a panel of 791 antibodies
Authors: Lorenz Peter , Ruschpler Peter , Koczan Dirk , Stiehl Peter , Thiesen Hans‐Jürgen 
Published: June 2003

AbstractGlobal scale molecular profiling of diseased tissues is an important first step to unravel candidate target molecules that are involved in the pathogenesis of a disease. We have performed a comparative molecular characterization at the transcriptome (microarray with 12 526 gene specificities) and proteome level (multi‐Western blot PowerBlot™ with 791 antibodies) of synovial tissue from rheumatoid arthritis (RA) compared to osteoarthritis (OA) patients. From the panel of 791 antibodies, 260 (33%) detected their corresponding protein. Out of 58 unambiguous changes at the protein level only 16 coincided at the transcript level (28%). Stat1, p47phox and manganese superoxide dismutase were shown to be reproducibly overexpressed in RA versus OA synovial tissue by Western blots with a panel of 8 RA versus 8 OA samples. Cathepsin D was among the most prominent proteins scored to be underexpressed in RA by the PowerBlot™ whereas no differences of the respective transcript were observed. The lower abundance of cathepsin D protein in RA compared to OA tissue was also reproduced in other patient samples. Immunohistochemistry assigned the Stat1 protein in RA synovial tissue mainly to macrophages and T lymphocytes and the p47phox protein in particular to macrophages. In conclusion, our approach provided us with new candidate molecules for further analysis of rheumatic diseases and stressed the importance of studies at the protein level.
Proteomic changes in Escherichia coli TG1 after metabolic engineering for enhanced trichloroethene biodegradation
Authors: Pferdeort Valerie A. , Wood Thomas K. , Reardon Kenneth F. 
Published: June 2003

AbstractThrough metabolic engineering, new enzymatic pathways can be introduced into cells to enable or enhance production or biotransformation of chemicals. However, these changes have physiological consequences that can be important but are not well understood. Here we describe the use of two‐dimensional gel electrophoresis (2‐DE) to detect changes in the proteome of Escherichia coli cells that have been engineered to transform the pollutant trichloroethene (TCE) with the enzyme toluene o‐monooxygenase (TOM). Comparison of 2‐DE gels (isoelectric point range 4–7) for E. coli cells with and without the ability to synthesize TOM revealed 31 new proteins in TOM‐containing cells as well as nine proteins not detected in those cells but present in the plasmid control strain. Exposure of TOM‐containing cells to TCE led to the synthesis of four new proteins and the loss of only one protein. Thus, this example of metabolic engineering has a substantial and complex impact on the physiology of these cells that was clearly revealed using a proteomic approach.
Rotational isomerism in 3,4‐alkylenedioxy‐2,5‐bis[di(tert‐butyl)hydroxymethyl]thiophenes>
Authors: Lomas John S. , Cordier Christine 
Published: June 2003

AbstractIn 3,4‐ethylenedioxy‐2,5‐bis[di(tert‐butyl)hydroxymethyl]thiophene there are three rotational isomers, syn,syn (SS), anti,syn (AS) and anti,anti (AA) (syn, free; anti, hydrogen‐bonded), differing in the number (zero, one or two) of alcohol hydrogen atoms intramolecularly hydrogen bonded to the oxygen atoms of the bridge. When a methyl group is introduced into the bridge the AS rotamer can be distinguished from SA [where the first character indicates the orientation of the —C(t‐Bu)2OH group closer to the substituent] by means of a 1H NOESY experiment. Forms with ‘free’ OH groups are favoured by hydrogen‐bonding solvents, but the AS:SA ratio for the methyl derivative is solvent independent, slightly favouring the AS isomer. Whatever the solvent, the methyl group has no significant effect upon the equilibrium rotamer ratios. Rotation barriers for the various equilibria are of the order of 20 kcal mol−1. Copyright © 2003 John Wiley & Sons, Ltd.
Wettability of poly(styrene‐co‐acrylate) ionomers improved by oxygen‐plasma source ion implantation
Authors: Lim Hyuneui , Lee Yeonhee , Han Seunghee , Kim Youngwoo , Song Ju‐Myung , Kim Joon‐Seop 
Published: June 2003

AbstractThe surfaces of poly(styrene‐co‐acrylic acid) copolymers and their Na‐ and Cs‐neutralized ionomers were modified by O2‐plasma source ion implantation (PSII) treatment to improve the surface wettability. The changes in the surface wettability, composition, and structure upon the PSII treatment were examined with contact‐angle measurements and X‐ray photoelectron spectroscopy. The untreated surfaces of the acid copolymers and ionomers exhibited different surface energies; this implied clearly that the type of ion species affects the surface hydrophilicity. Also, the PSII treatment induced oxygen‐containing groups to reside on the surface and ionic groups to come out toward the surface; this made the surfaces of the ionomers more hydrophilic as compared with that of the acid copolymers. The ionomers also showed slow hydrophobic recovery. Thus, it was suggested that the reduced mobility of the polymer chain because of the presence of ionic aggregates results in restricted reorientation of oxygen‐containing groups. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1791–1797, 2003
Fabrication and properties of poly(propylene carbonate)/calcium carbonate composites
Authors: Li X. H. , Tjong S. C. , Meng Y. Z. , Zhu Q. 
Published: June 2003

AbstractComposites of poly(propylene carbonate) (PPC) reinforced with micrometric and nanometric calcium carbonate particles were prepared via melt mixing followed by compression molding. The morphology and mechanical and thermal behaviors of the composites were investigated. Static tensile tests showed that the tensile strength, stiffness, and ductility of the composites tended to increase with increasing contents of micrometric calcium carbonate particles. This improvement in the tensile properties was attributed to good interfacial adhesion between the fillers and matrix, as evidenced by scanning electron microscopy examination. However, because of the agglomeration of calcium carbonate nanoparticles during blending, those composites with nanoparticles exhibited the lowest tensile strength. Thermogravimetric measurements revealed that the incorporation of calcium carbonate into PPC resulted in a slight improvement in its thermooxidative stability. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1806–1813, 2003
The experience of leukaemia and bone marrow transplant: Searching for meaning and agency
Authors: Xuereb Mary Carmen , Dunlop Rosemary 
Published: June 2003

AbstractThis qualitative study examines the experience of haematological cancer as described by ten people who have been through leukaemia or lymphoma and a bone marrow transplant. The focus is on the interaction of these participants with this challenging experience and the meaning it had for them. The descriptions of their thoughts, feelings and actions as they negotiated the period from diagnosis to treatment and survival reveal that these people brought both the present values in their life, as well as a life‐long pattern of dealing with adversity, into their confrontation of a life‐threatening illness. Issues of personal meaning and agency (the capacity to act and control valued aspects of one's life) were found to be paramount. These results are then discussed with a view to their implications for patient care. Copyright © 2003 John Wiley & Sons, Ltd.
Asthma mortality in the Danish child population: risk factors and causes of asthma death
Authors: Jørgensen Inger Merete , Jensen Vagn B. , Bülow Susanne , Dahm Thomas L. , Prahl Palle , Juel Knud 
Published: June 2003

AbstractChild death due to asthma is a rare and potentially preventable event. We investigated possible risk factors for death due to asthma in children and adolescents, as a step towards preventing or minimizing asthma death in this age group, and improving asthma management and care. We reviewed all 108 cases of asthma death in 1–19‐year‐olds in Denmark, 1973–1994. Copies of death certificates, hospital records, information from general practicioners, and autopsy records were obtained. The information was assessed with particular reference to: features and duration of asthma before death; severity of asthma; time and place of death; long‐term and ongoing medical treatment; quality of medical care; circumstances of final illness; and medical treatment during the final episode of asthma. Age groups of 1–4 years, 5–14 years, and 15–19 years were analyzed separately and in aggregate. Death occurred predominantly in the 15–19‐year age group. Generally, significantly more patients died in the summer. These patients were more atopic, had fewer asthma symptoms, and did not have regular asthma consultations. Nearly all patients had early‐onset asthma. The 1–4‐year age group was characterized by severe asthma. Major risk factors (all age groups) were: gradual deterioration during the last month; length of final attack (>3 hr); and delay in seeking medical help during the final attack. None of the children died during their first attack. Nonadherence was most frequent among the 15–19‐year‐olds. All asthmatic children and young adults should regularly receive medical care and assessment, even if they suffer only a few symptoms. This study underlines the need for ongoing education of the patient's family, the patient, and doctors on long‐term management and management of acute attacks. Copies of clearly written individual plans for periods with increasing symptoms should be supplied to the patient/family and, where appropriate, to their general practicioners. The object of these measures is that the patient and parents/family learn to recognize the signs of deterioration and to act on them. Pediatr Pulmonol. 2003; 36:142–147. © 2003 Wiley‐Liss, Inc.