bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential scanning calorimetry studies on high‐ and low‐density annealed and irradiated polyethylenes: Influence of aging
Authors: Vallés‐Lluch A. , Contat‐Rodrigo L. , Ribes‐Greus A. 
Published: July 2003

AbstractThe effect of γ‐radiation, followed by 10 years storage at ambient conditions, on the thermal behavior of different types of high‐ and low‐density commercial polyethylenes was studied. First, samples were annealed to improve the crystalline content. Next, they were irradiated, after which fusion endotherms, melting temperatures, crystallinity indices, and lamellar thicknesses were obtained by differential scanning calorimetry (DSC). The change in the thermal parameters for the first and second meltings were related to the absorbed doses. Afterward, the samples were stored at ambient conditions for 10 years and then scanned again by DSC to assess the influence of aging on previously irradiated samples. The results showed that the changes on the morphological structure undergone by the samples with the storage time were highly dependent on the polyethylene type and the absorbed radiation dose. The high‐density polyethylene was the most sensitive to radiation and storage, whereas the low‐density polyethylene with the lowest molecular weight and the highest degree of branching was the least affected. In general, the changes observed during irradiation can be explained in terms of an increase of imperfections and chain scissions. The storage can be understood as a slow crystallization process at low radiation doses, and as a decrease of the crystalline structure at high doses. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3260–3271, 2003
Melt processable and biodegradable aliphatic polycarbonate derived from carbon dioxide and propylene oxide
Authors: Li X. H. , Meng Y. Z. , Zhu Q. , Xu Y. , Tjong S. C. 
Published: July 2003

AbstractAlternating poly(propylene carbonate)s (PPC)s were successfully synthesized from carbon dioxide and propylene oxide in higher yield than previously reported. Such thermally stable and high molecular weight copolymers were achieved by optimizing the reaction conditions. The molecular structural change and mechanical properties of the alternating copolymer subjected to melt extrusion were examined by means of modulated differential scanning calorimetry (MDSC), thermogravimetric analysis (TGA), NMR, and tensile tests. The MDSC and TGA results showed that the alternating copolymer generally exhibits a high glass‐transition temperature of above 40°C and a decomposition temperature of above 250°C. These PPCs can be readily melt processed under conditions similar to those for commercial polyolefins. For instance, they can be melt extruded in a temperature range from 150 to 170°C under varying extrusion pressures. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3301–3308, 2003
Formation and inhibition of free radicals in electrically stressed and aged insulating polymers
Authors: Li Z. , Yin Y. , Wang X. , Tu D. M. , Kao K. C. 
Published: July 2003

AbstractPrevious work has shown that prebreakdown, electrical aging, and breakdown phenomena are directly associated with charge carriers injected from electrical contacts and their subsequent dissociative trapping and recombination. In addition, the energy released from each trapping or recombination event is dissipated in the breaking of the bonds of macromolecules, thus forming free radicals and new traps in the electrically stressed insulating polymers, as predicted by Kao's model. It is this gradual degradation process that leads to electrical aging and destructive breakdown. New experimental results are presented to confirm previous findings and a new approach to inhibit the degradation process by the incorporation of suitable dopants into the polymer. The concentration of free radicals in the polymer increases with an increasing electric field at a fixed stress time of 250 h and with increasing stress time at a fixed electric field of 833 kV cm−1. The concentration of free radicals is directly related to the concentration of new traps created by stress. However, when suitable dopants are incorporated, the initiation voltage for the occurrence of electrical treeing and the breakdown strength are both increased. The dopants tend to create shallow traps and have little effect on the deep trap concentration. This implies that the dopants act as free‐radical scavengers that tend to satisfy the unpaired electrons of the broken bonds, which create new acceptor‐like electron traps and new shallow traps. By doing so, the shallow traps screen the deep traps, thereby reducing the energy released during trapping and recombination and the probability of breaking the macromolecular bonds and causing structural degradation. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3416–3425, 2003
Effects of poly(vinyl acetate) and poly(vinyl chloride‐co‐vinyl acetate) low‐profile additives on properties of cured unsaturated polyester resins. II. glass‐transition temperatures and mechanical properties
Authors: Huang Yan‐Jyi , Chen Tzong‐Shyang , Huang Jyh‐Gau , Lee Fuh‐Huah 
Published: July 2003

AbstractThree series of self‐synthesized poly(vinyl acetate)‐based low‐profile additives (LPAs), including poly(vinyl acetate), poly(vinyl chloride‐co‐vinyl acetate), and poly(vinyl chloride‐co‐vinyl acetate‐co‐maleic anhydride), with different chemical structures and molecular weights were studied. Their effects on the glass‐transition temperatures and mechanical properties for thermoset polymer blends made from styrene, unsaturated polyester, and LPAs were investigated by an integrated approach of the static phase characteristics, cured sample morphology, reaction kinetics, and property measurements. Based on Takayanagi mechanical models, the factors that control the glass‐transition temperature in each phase region of the cured samples and the mechanical properties are discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3347–3357, 2003
Specific heat and thermal diffusivity of vinylidene fluoride/trifluoroethylene copolymers
Authors: Wong Y. W. , Hui N. M. , Ong E. L. , Chan H. L. W. , Choy C. L. 
Published: July 2003

AbstractThe specific heat (C) and thermal diffusivity (D) of vinylidene fluoride (VDF)/trifluoroethylene copolymers with 70 and 56 mol % of VDF were measured between 200 and 390 K, and the thermal conductivity (K) was calculated from these data. C, D, and K were rather insensitive to the VDF content but varied significantly with the crystallinity. At room temperature, as the crystallinity increased from about 55 to 85%, C decreased by 17%, and D and K increased by 60 and 40%, respectively. For the copolymer with 70 mol % VDF, C exhibited a broad peak, whereas D showed an abrupt drop at the ferroelectric–paraelectric transition near 370 K on heating. The transition temperature on cooling was about 40 K below that observed in the heating run, thus revealing a large thermal hysteresis. For the copolymer with 56 mol % VDF, the transition temperature was much lower, the transition region was narrower, and the thermal hysteresis was barely observable. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3160–3166, 2003
Self‐immobilization of methylaluminoxane in metallocene‐induced olefin polymerization reactions
Authors: Denner Christine E. , Alt Helmut G. 
Published: July 2003

AbstractMetallocene complexes carrying one or two ω‐alkenyl ligands were activated with methylaluminoxane (MAO) to give homogeneous catalyst solutions. The reaction with ethylene formed heterogeneous catalysts by self‐immobilization. In the activation step, the ω‐alkenyl groups were transferred from the metal of the metallocene complex to the activating MAO agent and then underwent copolymerization reactions with ethylene induced by other active sites. This method is a universal approach to the heterogenization of homogeneous catalysts by copolymerization with ω‐alkenyl functionalized cocatalysts. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3379–3382, 2003
Structure‐mechanical properties relationship of poly(ethylene terephthalate) fibers
Authors: Šujica Milena Žiberna , Smole Majda Sfiligoj 
Published: July 2003

AbstractThe correlation between the fiber structure and mechanical properties of two different poly(ethylene terephthalate) fiber types, that is, wool and cotton types produced by three producers, was studied. Fiber structure was determined using different analytical methods. Significant differences in the suprastructure of both types of conventional textile fibers were observed, although some slight variations in the structure existed between those fibers of the same type provided by different producers. A better‐developed crystalline structure composed of bigger, more perfect, and more axially oriented crystallites was characterized for the cotton types of PET fibers. Crystallinity is higher, long periods are longer, and amorphous domains inside the long period cover bigger parts in this fiber type in comparison with the wool types of fibers. In addition, amorphous and average molecular orientation is higher. The better mechanical properties of cotton PET fiber types, as demonstrated by a higher breaking tenacity and modulus accompanied by a lower breaking elongation, are due to the observed structural characteristics. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3383–3389, 2003
Heart development in the spotted dolphin (Stenella attenuata)
Authors: Sedmera David , Misek Ivan , Klima Milan , Thompson Robert P. 
Published: July 2003

AbstractMarine mammals show many deviations from typical mammalian characteristics due to their high degree of specialization to the aquatic environment. In Cetaceans, some of the features of limbs and dentition resemble very ancestral patterns. In some species, hearts with a clearly bifid apex (a feature normally present during mammalian embryogenesis prior to completion of ventricular septation) have been described. However, there is a scant amount of data regarding heart development in Cetaceans, and it is not clear whether the bifid apex is the rule or the exception. We examined samples from a unique collection of embryonic dolphin specimens macroscopically and histologically to learn more about normal cardiac development in the spotted dolphin. It was found that during the dolphin's 280 days of gestation, the heart completes septation at about 35 days. However, substantial trabecular compaction, which normally occurs in chicks, mice, and humans at around that time period, was delayed until day 60, when coronary circulation became established. At that time, the apex still appeared bifid, similarly to early fetal mouse or rat hearts. By day 80, however, the heart gained a compacted, characteristic shape, with a single apex. It thus appears that the bifid apex in the adult Cetacean heart is probably particular to certain species, and its significance remains unclear. Anat Rec Part A 273A:687–699, 2003. © 2003 Wiley‐Liss, Inc.
EBAG9/RCAS1 expression and its prognostic significance in prostatic cancer
Authors: Takahashi Satoru , Urano Tomohiko , Tsuchiya Fujiko , Fujimura Tetsuya , Kitamura Tadaichi , Ouchi Yasuyoshi , Muramatsu Masami , Inoue Satoshi 
Published: July 2003

AbstractEstrogen receptor‐binding fragment‐associated gene 9 (EBAG9) has been identified as a primary estrogen‐responsive gene from MCF‐7 human breast cancer cells (Watanabe T, et al., Mol Cell Biol 1998;18:442–9). EBAG9 is identical with RCAS1 (receptor‐binding cancer antigen expressed on SiSo cells), which has been reported as a cancer cell surface antigen implicated in immune escape ( M, et al., Nat Med 1999;5:938–42). In our present study, we examined EBAG9 expression in human prostatic tissues and investigated its prognostic significance in patients with prostatic cancer. EBAG9 expression in normal prostatic epithelial cells and PC‐3, DU145 and LNCaP cancer cells was determined by Western blot analysis. Immunohistochemic analysis was performed in 21 benign and 81 malignant prostatic specimens, and patients' charts were reviewed for clinical, pathologic and survival data. EBAG9 was abundantly expressed in the prostate cancer cells compared to the normal epithelial cells. Strong and diffuse immunostaining in the cytoplasm of EBAG9 was found in 44 of 81 (54%) cancerous tissue samples. EBAG9 expression significantly correlated with advanced pathologic stages and high Gleason score (p = 0.0305 and < 0.0001, respectively). EBAG9 was more frequently expressed at sites of capsular penetration (79%) and lymph node metastasis (100%) compared to intracapsular primary tumors (54%) (p = 0.0264 and 0.0048, respectively). Positive EBAG9 immunoreactivity significantly correlated with poor PSA failure‐free survival (p = 0.0059). EBAG9/RCAS1 may play a significant role in cancer progression via an immune escape system. Immunodetection of EBAG9/RCAS1 expression can be a negative prognostic indicator for patients with prostatic cancer. © 2003 Wiley‐Liss, Inc.
Active stromelysin‐3 (MMP‐11) increases MCF‐7 survival in three‐dimensional Matrigel culture via activation of p42/p44 MAP‐kinase
Authors: Fromigué Olivia , Louis Krystel , Wu Erxi , Belhacène Nathalie , Loubat Agnès , Shipp Margaret , Auberger Patrick , Mari Bernard 
Published: July 2003

AbstractStromelysin‐3 (ST3) has the characteristic structure of matrix metalloproteinases (MMP), but its substrate specificity and pattern of expression differ markedly from that of other MMP family members. ST3 was originally isolated on the basis of its expression in primary breast cancers and has been shown to be overexpressed in virtually all primary carcinomas, suggesting that ST3 participates in the initial development of epithelial malignancies. Recent data using murine models reported that ST3 expression was able to increase tumor take by suppressing cell apoptosis. Our present goal was to set up an in vitro model in which we could study this new function. For this purpose, we analyzed survival of MCF‐7 transfectants expressing either wild‐type or catalytically inactive ST3 (ST3wt or ST3cat‐) in three‐dimensional (3‐D) culture conditions by inclusion in Matrigel. In such conditions, that mimic the in vivo microenvironment, we found a marked decrease in the percentage of cell death when active ST3 was expressed (ST3wt transfectants vs. ST3cat‐ or vector only transfectants) as assessed by FACS and TUNEL analysis. The addition of batimastat, a broad spectrum MMP inhibitor, reversed the increased cell survival in ST3wt transfectants, confirming that ST3 enzymatic activity was required for this effect. Finally, we analyzed the expression of anti‐ and pro‐apoptotic proteins as well as activation of cell survival pathways and we found that ST3‐mediated cell survival was accompanied by activation of both p42/p44 MAPK and AKT. Our data confirm and extend the anti‐apoptotic function of ST3 and provide a useful model to dissect this new role and identify new physiological substrates. © 2003 Wiley‐Liss, Inc.
Tartrate‐resistant acid phosphatase isoform 5b: A novel serum marker for monitoring bone disease in multiple myeloma
Authors: Terpos Evangelos , de la Fuente Josu , Szydlo Richard , Hatjiharissi Evdoxia , Viniou Nora , Meletis John , Yataganas Xenophon , Goldman John M , Rahemtulla Amin 
Published: July 2003

AbstractTartrate‐resistant acid phosphatase isoform‐5b (TRACP‐5b), a new marker reflecting osteoclast activity, and osteoprotegerin (OPG) were measured in 121 patients with multiple myeloma (MM) at diagnosis, and in 63 of them during pamidronate administration, to define their correlation with the extent of bone disease and disease activity in MM. Radiographic evaluation of the skeleton, measurement of other markers of bone remodelling, including N‐terminal cross‐linking telopeptide of type‐I collagen (NTX), bone alkaline phosphatase and osteocalcin and of markers of disease activity (beta2‐microglobulin, paraprotein, interleukin‐6 (IL‐6), were also performed. Levels of TRACP‐5b were increased (p < .0001), while OPG was decreased in MM patients compared to controls (p < .01). TRACP‐5b levels were associated with the radiographically assessed severity of bone disease (p < .0001) as well as with levels of NTX, IL‐6 and beta2‐microglobulin (p < .001, for each biochemical parameter, respectively). The combination of pamidronate with VAD‐chemotherapy produced a reduction in TRACP‐5b, NTX, IL‐6, paraprotein and beta2‐microglobulin levels from the 2nd month of treatment, with no effect on bone formation and OPG. A strong correlation was observed between changes in TRACP‐5b and changes in NTX, IL‐6 and beta2‐microglobulin, while TRACP‐5b predicted the disease progression in 5 patients. These findings suggest that TRACP‐5b is increased in MM, reflects the extent of myeloma bone disease and may have a predictive value. TRACP‐5b has also proved to be very useful for monitoring antimyeloma treatment, which had no effect on OPG levels. © 2003 Wiley‐Liss, Inc.
Dosage, duration and timing of nonsteroidal antiinflammatory drug use and risk of prostate cancer
Authors: Perron Linda , Bairati Isabelle , Moore Lynne , Meyer François 
Published: July 2003

AbstractExperimental studies suggest that NSAIDs could reduce prostate cancer risk. Results of observational studies on the relation between NSAIDs and prostate cancer risk have, however, been inconsistent. Moreover, none has addressed the issues of dosage, duration and timing of exposure. In a population‐based, age‐matched case‐control study, we measured the association between prostate cancer risk and NSAIDs defined in terms of mean daily dose, cumulative duration and timing of exposure. Eight‐year drug exposure history was obtained from the Quebec health insurance system database. Parallel analyses were performed for aspirin and NSAIDs other than aspirin. We controlled for detection bias and assessed the potential impact of protopathic bias. Analyses were performed with conditional logistic regression. Among the 2,221 cases and 11,105 controls, there was a negative trend between cumulative duration of aspirin use and prostate cancer risk (p = 0.0009). Also, exposure to a mean daily dose of aspirin of at least 80 mg, maintained throughout the entire 8 years of follow‐up, was associated with an 18% reduction in prostate cancer risk (OR = 0.82, 95% CI 0.71–0.95). In more recent users of such a dose, the risk reduction was 7%. However, 1 year after the end of a 7‐year regular aspirin exposure, no residual protective effect persisted. No association was observed between prostate cancer risk and exposure to NSAIDs other than aspirin. The results suggest that long‐term and regular use of aspirin, at a dosage beneath that usually recommended for an anti‐inflammatory effect, may prevent prostate cancer. © 2003 Wiley‐Liss, Inc.
Incidence and survival of Swedish patients with differentiated thyroid cancer
Authors: Lundgren Catharina Ihre , Hall Per , Ekbom Anders , Frisell Jan , Zedenius Jan , Dickman Paul W. 
Published: July 2003

AbstractPapillary (PTC) and follicular (FTC) thyroid cancers are rare disorders but are, nevertheless, among the most common cancers in individuals below 40 years of age. From the population‐based Swedish Cancer Registry we identified 3,588 individuals with PTC and 1,966 with FTC during 1958–87. Histopathology was determined by examining the original histopathology reports. The relative survival ratio (RSR) was used as the measure of patient survival. Incidence of both PTC and FTC was higher among women, especially for PTC and particularly during the fertile part of female life. Incidence of PTC increased significantly over time, a trend that was not observed for FTC. Five‐year relative survival appeared to be higher for patients diagnosed with PTC compared to FTC, although this difference was almost completely explained by the confounding effect of age. Patients with PTC experience lower mortality during the period 7–20 years after diagnosis. Excess mortality was lower among women, although the magnitude of the difference varied with age and histopathology. In contrast to our perceptions based on clinical practice, we observed no difference in excess mortality between patients diagnosed with PTC and FTC during the years immediately after diagnosis (where the majority of deaths occur). Our data suggest that there may exist a subgroup of thyroid tumors with superior prognosis diagnosed in women during the fertile part of female life. Sex hormones may play a role in the etiology of these tumors. © 2003 Wiley‐Liss, Inc.
Anti‐CD30‐IL‐12 antibody‐cytokine fusion protein that induces IFN‐γ secretion of T cells and NK cell‐mediated lysis of Hodgkin's lymphoma‐derived tumor cells
Authors: Heuser Claudia , Diehl Volker , Abken Hinrich , Hombach Andreas 
Published: July 2003

AbstractInterleukin‐12 (IL‐12) is a disulfide‐linked p40‐p35 heterodimeric cytokine and plays a key role in linking innate cellular immunity to an adaptive Th1 response against pathogens and tumor cells and in counteracting a Th2 immune response. The pathogenesis of Hodgkin's disease (HD) is partially attributed to a Th2 dominance associated with functional anergy of T cells that accumulate in the near vicinity to the malignant Hodgkin/Reed‐Sternberg (H/RS) cells. To revert Th2 polarization in the tumor lesion, we generated an anti‐CD30‐IL‐12 antibody‐cytokine fusion protein that binds to CD30 on H/RS cells and is composed of a CD30 binding domain (HRS3‐scFv) linked to p40‐p35 murine single chain IL‐12. The HRS3‐scFv‐hi‐IL‐12 fusion protein is expressed as a 110 kD polypeptide, can be purified by affinity chromatography, and has binding specificities to both the CD30 antigen and the IL‐12 receptor. After binding to CD30+ H/RS cells, the fusion protein stimulates T cells to secrete IFN‐γ, a predominant Th1 cytokine, and induces NK cells to lyse CD30+ cells with high efficiency. These properties make the HRS3‐scFv‐hi‐IL‐12 fusion protein suitable for the specific immunotherapy of Hodgkin's lymphoma. © 2003 Wiley‐Liss, Inc.