bluuebunny/crossref_metadata_2025_split huggingface dataset:
Filler fraction effect on creep response of crosslinked polyester matrix with mineral filler
Authors: Hristova J. , Minster J. 
Published: July 2003

AbstractThe effect of a particle marble filler on the creep response of a crosslinked polyester matrix before and after physical aging is described. Composites with various filler–polyester matrix percentages are prepared by applying mixing technology, curing at room temperature, and postcuring above the glass‐transition temperature. Two groups of specimens of identical composition are studied. The first group is tested 1 month after preparation (relatively nonaged), whereas the second group is tested after 13 years of storage at stable room temperature and humidity, at current atmospheric pressure, and in the absence of direct light (aged). The two groups of specimens (aged and nonaged) are subjected to creep measurements. The modulus of elasticity and the creep compliance are determined, plotted against the filler volume fraction, and fit by empirical equations. A simple mechanical model is proposed to fit the compliance curves, and good agreement between the measured and predicted values is shown. The mechanical behavior of the composites is also described, using empirical equations that fit the relation between the composite/matrix ratio of the deformation characteristics and the filler volume fraction. A crucial matrix influence is proposed to fit the compliance curves, and good agreement between the measured and predicted values is shown. Experimentally established natural regularities can be used to predict the creep compliances of composites from a less demanding experimental program. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3329–3335, 2003
Atom transfer radical polymerization of n‐butyl methacrylate in an aqueous dispersed system
Authors: Peng Hui , Cheng Shiyuan , Feng Linxian , Fan Zhiqiang 
Published: July 2003

AbstractAtom transfer radical polymerization of n‐butyl methacrylate (BMA) was conducted in an aqueous dispersed system with different kinds of copper complexes. The partitioning behavior of the copper complexes, including CuCl/4,4′‐di(5‐nonyl)‐2,2′‐bipydine (dNbpy), CuCl2/dNbpy, CuCl/2,2′‐bipydine (bpy), CuCl2/bpy, CuCl/bis(N,N′‐dimethylaminoethyl)ether (bde), and CuCl2/bde between the monomer (BMA), and water was studied in detail with ultraviolet‐visible spectroscopy. The results show that with a less hydrophobic ligand, such as bpy or bde, most of the Cu(I) or the Cu(II) complexes migrated from the BMA phase to the aqueous phase, the atom transfer equilibrium was destroyed, and the polymerization was nearly not controlled; it converted to classical emulsion polymerization. As to the very hydrophobic ligand dNbpy, although the partitioning study of the copper complexes indicated that not all the copper species were restricted to the organic phase, the linear correlation between the molecular weight and the monomer conversion and the narrow polydispersities confirmed that the polymerization was still quite well controlled. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3175–3179, 2003
Polymorphism in polypropylene fibers
Authors: Broda Jan 
Published: July 2003

AbstractThe structure of polypropylene fibers formed by different spinning conditions was studied. The investigations were carried out using wide‐angle X‐ray scattering (WAXS) and small‐angle X‐ray scattering (SAXS) methods. It was stated that in noncolored fibers the mesophase and the monoclinic α forms were formed. The highest content of the mesophase was observed for fibers extruded at the higher temperature and taken at the medium take‐up velocity. In fibers colored with quinacridone pigment the structure containing the monoclinic α and the trigonal β forms was obtained. The highest content of the β form occurred in fibers taken at the lowest take‐up velocity. The increase of the take‐up velocity caused a rapid drop in β form content. In fibers taken at higher velocities only the α form was formed. It was found that the content of different forms as well lamellar thickness depends on crystallization conditions, which were influenced by the formation parameters. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3364–3370, 2003
A combinatorial approach in designing hydrophilic surfaces for solid‐phase peptide synthesis
Authors: Ercole Francesca , FitzGerald Michael , Perera Senake , Ede Nicholas , Riley Phil , Campbell Rhonda 
Published: July 2003

AbstractA hydrophilic surface suitable for solid‐state peptide synthesis was developed on a solid support called a lantern. The split‐and‐mix combinatorial technique was used to prepare about 500 surfaces in a very short time. Surfaces were analyzed according to values for gel formation, percentage weight grafted, grafted copolymer composition, and number of functional groups per lantern. These values were correlated to the purity of a peptide synthesized on these surfaces. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3371–3378, 2003
Crystallization kinetics and PVT behavior of poly(vinylidene fluoride) in process conditions
Authors: Pantani R. , Speranza V. , Besana G. , Titomanlio G. 
Published: July 2003

AbstractThe so‐called fluoropolymers have gained, in recent years, considerable industrial success, and the increasing industrial interest in this class of materials has caused a need for better characterization of the properties of interest for processability, for instance, for injection molding or extrusion. In this work, the pressure–volume–temperature (PVT) relationship of a poly(vinylidene fluoride) is described by combining specific volumes of amorphous and crystalline phases present in the material. The volumes of the two phases are described simply by thermal expansion and compressibility coefficients drawn from standard PVT data below and above the crystallization range. Within the crystallization range, the material volume is assumed to change from amorphous to crystalline according to the evolution of an overall crystallinity degree, which is described by the Nakamura nonisothermal formulation of an Avrami crystallization kinetic model. Model parameters are identified by comparison with standard calorimetric results, PVT data, and final densities of thin samples solidified during quenches conducted with cooling rates of several hundreds of Kelvins/second. The resulting model allows the description of the PVT behavior of PVDF in the pressure ‐and cooling‐rate ranges of interest for processing. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3396–3403, 2003
Oligophrenin‐1, a Rho GTPase‐activating protein (RhoGAP) involved in X‐linked mental retardation, is expressed in the enteric nervous system
Authors: Xiao Junhua , Neylon Craig B. , Hunne Billie , Furness John B. 
Published: July 2003

AbstractOligophrenin‐1 is a RhoGTPase‐activating protein (RhoGAP) that is involved in the regulation of shape changes in dendritic spines, and outgrowth of axons and dendrites in the brain. These changes in neuronal morphology are central to the mechanisms of plasticity, learning, and memory. Although the enteric nervous system also exhibits long‐term changes in neuronal function, the expression and involvement of oligophrenin‐1 has not previously been investigated. We show by RT‐PCR analysis that oligophrenin‐1 mRNA is expressed in the myenteric plexus (MP) of the guinea pig ileum. Sequencing of RT‐PCR products showed that guinea pig oligophrenin‐1 mRNA is 98% and 87% homologous to human and mouse oligophrenin‐1, respectively, except that a 42 bp sequence is absent from the guinea pig mRNA. This 42 bp sequence codes for a sequence of 14 amino acids located near the carboxy‐terminal end of the RhoGAP domain in the human sequence. An antibody that recognizes human oligophrenin‐1 identified a 91 kDa protein band in rat and mouse brain lysates and in guinea pig sciatic nerve, and a 36 kDa protein band in both purified enteric ganglion cell and brain lysate from guinea pig. Oligophrenin‐1 is localized specifically to neurons and varicose axons in the MPs and submucosal plexuses (SMPs) of the guinea pig and rat, but is not detectable in glial cells, smooth muscle, or other cell types. These findings indicate that oligophrenin‐1 is expressed in the enteric nervous system, where it may regulate morphological changes in axons and dendrites, and thus modulate neuronal connectivity. Anat Rec Part A 273A:671–676, 2003. © 2003 Wiley‐Liss, Inc.
Effect of lacunocanalicular architecture on hydraulic conductance in bone tissue: Implications for bone health and evolution
Authors: Mishra Sanjay , Knothe Tate Melissa L. 
Published: July 2003

AbstractBone tissue health depends largely on efficient fluid and solute transport between the blood supply and cells that are the living component of the tissue. We hypothesized that the lacunocanalicular hydraulic network, which is defined by the pericellular fluid space that is common to all bone tissue, is optimized to transport fluid and solutes between the blood supply and bone cells. An analytical study was carried out to evaluate the effect of osteonal architecture, including the osteon diameter, number of annular lamellar regions, and number and length of canalicular channels, on fluid transport between the blood supply and bone cells. On the basis of this analysis, we conclude that osteon size is limited to the distance over which fluid and solutes can be transported efficiently between the blood supply and cells. This analytic model suggests that hydraulic conductivity is highest in lamellar regions closest to the Haversian canal (HC) and decreases with increasing distance from the blood supply, reaching a plateau after the fifth lamella (169 μm radius). Furthermore, an increase in the diameter of the HC, or a decrease in the length of canaliculi, reduces the hydraulic conductivity within the lacunocanalicular network. Applying the principle of minimal expenditure of energy to this analysis, the path distance comprising five or six lamellar regions represents an effective limit for fluid and solute transport between the blood supply and cells; beyond this threshold, hydraulic resistance in the network increases and additional energy expenditure is necessary for further transportation. This suggests that transport is optimized to meet metabolic demands concomitant with a minimal expenditure of energy. This fundamental new insight into bone structure and physiology may provide a new basis of understanding for tissue engineering, bone physiology in health and disease, and evolutionary biology. Anat Rec Part A 273A:752–762, 2003. © 2003 Wiley‐Liss, Inc.
Histological studies of bone formation during pedicle restoration and early antler regeneration in roe deer and fallow deer
Authors: Kierdorf Uwe , Stoffels Elke , Stoffels Dieter , Kierdorf Horst , Szuwart Thomas , Clemen Günter 
Published: July 2003

AbstractThe purpose of the present study was to examine the process of bone formation in the regenerating cranial appendages of roe deer (Capreolus capreolus) and fallow deer (Dama dama) during the early postcasting period. After the antlers are cast, osteoclastic and osteoblastic activities lead to a smoothing of the pedicle's separation surface, a strengthening of the pedicle bone, and a partial restoration of the distal pedicle portion that was lost along with the cast antler. Initially, bone formation occurs by intramembranous ossification, but early during the regeneration process cartilage is formed at the tips of the cranial appendages, and is subsequently replaced by bone in a process of endochodral ossification. Shortly after the antlers are cast, the cambium layer of the periosteum in the distal pedicle is markedly enlarged, which suggests that the periosteum serves as a cell source for the bone‐forming tissue covering the exposed pedicle bone. The histological findings of our study are consistent with the view that the bony component of the regenerating cranial appendages of deer is largely derived from the pedicle periosteum. Based on findings in other bone systems, we speculate that stem cells that can undergo both osteogenic and chondrogenic differentiation are present in the pedicle periosteum. The early onset of chondrogenesis in the regeneration process is regarded as an adaptation to the necessity of producing a huge volume of bone within a short period. This parallels the situation in other cases of chondrogenesis in membrane bones. Anat Rec Part A 273A:741–751, 2003. © 2003 Wiley‐Liss, Inc.
Immunolocalization of calbindin D28k and vitamin D receptor during root formation of murine molar teeth
Authors: Onishi Tomoyuki , Okawa Rena , Murakami Hiroaki , Ogawa Tomohiro , Ooshima Takashi , Wakisaka Satoshi 
Published: July 2003

AbstractCells in the epithelial rest of Malassez (ERM cells) express calbindin D28k (CB); however, the hormonal regulation of CB in ERM cells remains to be elucidated. We investigated the immunohistochemical localization of CB and 1,25‐dihydroxyvitamin D3 receptor (VDR) during root formation of mouse molar teeth in order to clarify whether the expression of CB in ERM cells is dependent on vitamin D. At the early stage of root formation (postnatal (PN) days 10–14), both CB‐ and VDR‐immunoreactive cells were observed intermittently along the root surface. In the apical portion, almost all CB‐immunoreactive cells showed VDR immunoreactivity; however, VDR‐immunoreactive cells in the most apical portion were immunonegative for CB. In the middle and cervical portions, the distributions of the two proteins were completely different. At the late stage of root formation (PN28d) and in adult animals, CB immunoreactivity was distributed in cells found along the acellular cementum at the bifurcation region, as well as between the dentin and cellular cementum in the apical portion (although these lacked immunoreactivity for VDR). The present results indicate that CB expression in newly disrupted cells from Hertwig's epithelial root sheath occurs in a vitamin‐D dependent manner, whereas the expression of CB in mature ERM cells may be independent of vitamin D. Anat Rec Part A 273A:700–704, 2003. © 2003 Wiley‐Liss, Inc.
Immortalization of normal human embryonic fibroblasts by introduction of either the human papillomavirus type 16 E6 or E7 gene alone
Authors: Yamamoto Akito , Kumakura Shin‐ichi , Uchida Minoru , Barrett J. Carl , Tsutsui Takeki 
Published: July 2003

AbstractThe ability of the human papillomavirus type 16 (HPV‐16) E6 or E7 gene to induce immortalization of normal human embryonic fibroblast WHE‐7 cells was examined. WHE‐7 cells at 9 population doublings (PD) were infected with retrovirus vectors encoding either HPV‐16 E6 or E7 alone or both E6 and E7 (E6/E7). One of 4 isolated clones carrying E6 alone became immortal and is currently at >445 PD. Four of 4 isolated clones carrying E7 alone escaped from crisis and are currently at >330 PD. Three of 5 isolated clones carrying E6/E7 were also immortalized and are currently at >268 PD. The immortal clone carrying E6 only and 2 of the 3 immortal clones carrying E6/E7 expressed a high level of E6 protein, and all the immortal clones carrying E7 alone and the other immortal clone carrying E6/E7 expressed a high level of E7 protein when compared to their mortal or precrisis clones. The immortal clones expressing a high level of E6 or E7 protein were positive for telomerase activity or an alternative mechanism of telomere maintenance, respectively, known as ALT (alternative lengthening of telomeres). All the mortal or precrisis clones were negative for both phenotypes. All the immortal clones exhibited abrogation of G1 arrest after DNA damage by X‐ray irradiation. The expression of INK4a protein (p16INK4a) was undetectable in the E6‐infected mortal and immortal clones, whereas Rb protein (pRb) was hyperphosphorylated only in the immortal clone. The p16INK4a protein was overexpressed in all the E7‐infected immortal clones and their clones in the pre‐crisis period as well as all the E6/E7‐infected mortal and immortal clones, but the pRb expression was downregulated in all of these clones. These results demonstrate for the first time to our knowledge that HPV‐16 E6 or E7 alone can induce immortalization of normal human embryonic fibroblasts. Inactivation of p16INK4a/pRb pathways in combination with activation of a telomere maintenance mechanism is suggested to be necessary for immortalization of normal human embryonic fibroblasts by these viral oncogenes. The susceptibility of human cells to immortalization may be related to the state of differentiation of the cells. © 2003 Wiley‐Liss, Inc.
Overexpression of thymidylate synthase mediates desensitization for 5‐fluorouracil of tumor cells
Authors: Saga Yasushi , Suzuki Mitsuaki , Mizukami Hiroaki , Kohno Takahiro , Takei Yuji , Fukushima Masakazu , Ozawa Keiya 
Published: July 2003

AbstractThe prognosis of cancers of various organs overexpressing thymidylate synthase (TS) has been reported to be poor. It has been suggested that the poor prognosis is partly due to a low sensitivity of TS‐overexpressing tumors to TS‐targeting 5‐fluorouracil (5‐FU). To investigate the relationship between TS expression and sensitivity to 5‐FU, we used the TS‐overexpressing cervical cancer cell line SKG‐II/TS and SKG‐I/TS that had been established by TS gene transfer. The 50% growth inhibitory concentration (IC50) of 5‐FU for SKG‐II/TS was 24 ± 6.0 μM, which was 6 times as high as that for the control (4.0 ± 1.1 μM), showing significantly decreased sensitivity to 5‐FU (p < 0.01). The IC50 of 5‐FU for SKG‐I/TS was 90 ± 15 μM, which was over 2 times as high as that for the control (40 ± 0.6 μM), showing significantly decreased sensitivity to 5‐FU (p < 0.05). Thus, TS‐overexpressing tumors have decreased sensitivity to 5‐FU, which may be one of the factors that determine the prognosis of these tumors. © 2003 Wiley‐Liss, Inc.
Cohort studies of association between self‐reported allergic conditions, immune‐related diagnoses and glioma and meningioma risk
Authors: Schwartzbaum Judith , Jonsson Fredrik , Ahlbom Anders , Preston‐Martin Susan , Lönn Stefan , Söderberg Karin C. , Feychting Maria 
Published: July 2003

AbstractAn inverse association between self‐reported allergies and glioma and meningioma risk, has been previously observed in case‐control studies. Approximately 27% (median) of the information on both glioma and meningioma in these studies, however, is collected from proxy respondents. In fact, the odds ratios (OR) among previous brain tumor studies are inversely related to the proportion of proxy respondents (Pearson correlation coefficient = −0.94; 95% CI = −1.00 to −0.65); this correlation suggests bias. We therefore constructed 3 cohorts based on the Swedish Twin, Hospital Discharge, and Cancer Registries. In Cohorts I (14,535 people developed 37 gliomas and 41 meningiomas) and II (29,573 people developed 42 gliomas and 26 meningiomas) median time from self‐report of allergies to brain tumor diagnosis was 15.4 years. Cohort III, which overlaps with Cohorts I and II (52,067 people developed 68 gliomas and 63 meningiomas), was linked to the Swedish Hospital Discharge Registry where pre‐brain tumor immune‐related discharge diagnoses were recorded. Allergies are inversely associated with glioma risk in Cohort I (Hazard ratio [HR] = 0.45; 95% CI = 0.19–1.07) and among high grade (III and IV, HR = 0.45; 95% CI = 0.11–1.92) but not low grade (I and II, HR = 2.60; 95% CI = 0.86–7.81) gliomas in Cohort II. In Cohort III, immune‐related discharge diagnoses are also inversely associated with glioma (HR = 0.46; 95% CI = 0.14–1.49). There is no strong evidence against (and some for) the hypothesis that allergies reduce glioma risk. © 2003 Wiley‐Liss, Inc.
A common 936 C/T gene polymorphism of vascular endothelial growth factor is associated with decreased breast cancer risk
Authors: Krippl Peter , Langsenlehner Uwe , Renner Wilfried , Yazdani‐Biuki Babak , Wolf Gerald , Wascher Thomas C. , Paulweber Bernhard , Haas Josef , Samonigg Hellmut 
Published: July 2003

AbstractA common 936 C/T polymorphism in the gene for the vascular endothelial growth factor (VEGF) has been associated with VEGF plasma levels. In our case‐control study, we investigated the role of this polymorphism for breast cancer risk. VEGF genotype was determined in 500 women with breast cancer and 500 sex‐ and age‐matched healthy control subjects. Carriers of a 936T‐allele were more frequent among controls (29.4%) than among patients (17.6%; p = 0.000014). The odds ratio for carriers of a 936T‐allele for breast cancer was 0.51 (95% confidence interval 0.38–0.70). Additionally, VEGF plasma levels were determined in 21 nonsmoking post‐menopausal controls; carriers of a 936T allele had significantly lower levels (median 23 pg/ml; range 6–50 pg/ml) than noncarriers (37; 21–387; p = 0.034). We conclude that carriers of a VEGF 936T‐allele are at decreased risk for breast cancer, this, however, requiring further confirmation in a larger study. © 2003 Wiley‐Liss, Inc.
Test characteristics of visual inspection with 4% acetic acid (VIA) and Lugol's iodine (VILI) in cervical cancer screening in Kerala, India
Authors: Sankaranarayanan Rengaswamy , Wesley Ramani , Thara Somanathan , Dhakad Namrata , Chandralekha Bharathykutty , Sebastian Paul , Chithrathara K. , Parkin Donald Maxwell , Nair Madhavan Krishnan 
Published: July 2003

AbstractSimple and inexpensive methods based on visual examination of the cervix are currently being investigated as alternative methods of cervical screening. The test characteristics of visual inspection with 4% acetic acid (VIA), and Lugol's iodine (VILI) and conventional cytology were investigated in a cross‐sectional study involving 4,444 women aged 25 to 65 years in Kerala, India. While detection of any acetowhite area constituted a low‐threshold positive VIA, detection of well‐defined, opaque acetowhite lesions close to or touching the squamocolumnar junction constituted a high‐threshold positive VIA test. Detection of definite yellow iodine nonuptake areas in the transformation zone close to or touching the squamocolumnar junction constituted a positive VILI test. Cytology was considered positive if reported as atypia or worse lesions. All screened women were evaluated by colposcopy and biopsies were directed in 1,644 women (37.0%), which allowed the direct estimation of sensitivity, specificity and predictive values. The reference diagnosis was based on a combination of histology and/or colposcopy. True disease status was defined as CIN 2 and worse lesions. A total of 149 (3.4%) women had CIN 2 or worse lesions. The sensitivities of low‐threshold VIA, high‐threshold VIA, VILI and cytology to detect CIN 2 or worse disease were 88.6%, 82.6%, 87.2% and 81.9%, respectively; the corresponding specificities were 78.0%, 86.5%, 84.7% and 87.8%. Our results indicate that VIA and VILI are suitable alternate screening tests to cytology for detecting cervical neoplasia in low‐resource settings. © 2003 Wiley‐Liss, Inc.