bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prenatal diagnosis of P450 oxidoreductase deficiency (ORD): A disorder causing low pregnancy estriol, maternal and fetal virilization, and the Antley–Bixler syndrome phenotype
Authors: Shackleton Cedric , Marcos Josep , Arlt Wiebke , Hauffa Berthold P. 
Published: August 2004

AbstractWe report studies on the second pregnancy of a woman who had previously given birth to a virilized female infant. The cause of the virilization had not been established, but common forms of congenital adrenal hyperplasia (CAH) were excluded. Longitudinal monitoring of the second pregnancy revealed that estriol excretion failed to increase normally, reaching a maximum 0.7 mg/24 hr at the end of pregnancy (normal mean 30 mg/24 hr). The mother showed signs of virilization by the 23rd week of gestation and aromatase deficiency was suspected. However, predicted urinary metabolites for diagnosis of aromatase deficiency (for example, 16α‐hydroxyandrosterone) were not increased significantly during the pregnancy. Interestingly, excretion of the androgen metabolite androsterone increased rapidly at the beginning of pregnancy and peaked around the 20th week, suggesting increased production of testosterone and 5αDHT, probably the cause of maternal virilization. Urine steroid analysis by GC/MS showed gradually increasing excretion (9 mg/24 hr) of the normally minor metabolite 5α‐pregnane‐3β,20α‐diol (epiallopregnanediol), an epimer of the dominant progesterone metabolite pregnanediol (5β‐pregnane‐3α,20α‐diol). We believe epiallopregnanediol is largely the maternal urinary excretion product of fetal 5‐pregnene‐3β,20α‐diol, the principal metabolite of pregnenolone, implying a build‐up of the latter steroid in the fetal adrenal. These findings suggested that the ‘block’ in the estriol biosynthetic pathway occurs at an early stage with 17‐hydroxylation of pregnenolone being affected. The male baby born of this pregnancy had normal genitalia but showed a urinary steroid profile indicating partial deficiencies of P450c17 and P450c21. However, no mutations in the corresponding CYP17 and CYP21 genes were identified. Urinary steroid analysis carried out on his virilized older sibling showed the same pattern of metabolites. Recently, we determined that this disorder is caused by mutations in P450 oxidoreductase (OR), the essential redox partner for CYP17 and CYP21 hydroxylases. The novel metabolic profile has now been seen in many patients, most diagnosed with the skeletal dysplasia Antley–Bixler syndrome. We propose that excessive excretion of epiallopregnanediol together with low estriol may be prenatally diagnostic for OR deficiency (ORD). © 2004 Wiley‐Liss, Inc.
Competition, predation, and the evolutionary significance of the cercopithecine cheek pouch: The case of Cercopithecus and Lophocebus
Authors: Lambert Joanna E. 
Published: August 2004

AbstractReports of cercopithecine cheek pouch use and functional significance are largely anecdotal, and to date there have been no investigations into its use by species living in closed forest habitats. Here, I report on cheek pouch use in Cercopithecus ascanius and Lophocebus albigena in the Kibale National Park, Uganda, between July–October 1997. Two hypotheses were evaluated: this feature was selected for because of its role in 1) increasing feeding efficiency via a reduction in potential feeding competition, and/or 2) reducing vulnerability to predation. Results indicate that both species were more likely to use their cheek pouches when feeding on contestable foods and, after filling cheek pouches, retreated to more densely vegetated (“safer”) positions for processing food. There was no influence of age and sex on L. albigena cheek pouch use. Subadult C. ascanius cheek‐pouched less frequently than adults, although there were no differences between adult males and females. There was no relationship between feeding‐patch size and number of plant food items cheek‐pouched in either species. However, the diameter of breast height (dbh; a measure of patch size) of trees in which C. ascanius used their cheek pouches was significantly larger than the dbh of trees in which they did not. Both species were more likely to use their cheek pouches in the presence of greater numbers of conspecifics. These data provide insight into the relationship(s) among oral anatomy and feeding efficiency, and facilitate understanding into the selection for this important oral feature in stem cercopithecines. Am J Phys Anthropol 126:183–192, 2005. © 2004 Wiley‐Liss, Inc.
The role of changing childhood diets in the prehistoric evolution of food production: An isotopic assessment
Authors: Schurr Mark R. , Powell Mary Lucas 
Published: August 2004

AbstractEarlier weaning has often been suggested as a cause for population growth after the evolution of food production. However, evidence for weaning‐time reduction is largely circumstantial. Collagen stable nitrogen‐ and carbon‐isotope ratios from juvenile and adult burials from four sites in eastern North America were measured to estimate weaning onsets and durations before and after the appearance of intensive food production. Two preagricultural Late Archaic sites (Indian Knoll and Carlston Annis) are compared with two highly agricultural Middle Mississippian sites (Angel and Tinsley Hill). Isotopic data and paleodemographic measures of birth rates provide no evidence for changes in weaning behavior or fertility with the development of food production in the prehistoric Lower Ohio Valley. Birth rates and weaning behavior appear to have been roughly the same at all four sites. These results indicate that models attributing population growth after the appearance of food production to earlier weaning are not universally applicable. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
Invisible impacts but long‐term consequences: Hypoplasia and contact in central Australia
Authors: Littleton Judith 
Published: August 2004

AbstractThe dental casts taken of Aboriginal people resident at Yuendumu, Central Australia, between 1950–1970 preserve a unique historical record of defects of the dental enamel (DDEs) among people born from 1890–1960 (n = 377). These data are used, in comparison with precontact data, to trace the chronological changes in childhood development that occurred among Aboriginal people from the point of initial engagement with white settlers to a period of overwhelming government control. The results demonstrate very little change in the frequency of DDE from the precontact period to 1929 but increases after that time, particularly after the forcible settlement of people on a government establishment at Yuendumu in 1946. Apart from the absolute increase in frequency, it is also clear that population variation decreased markedly, with growing numbers of children experiencing multiple defects in early childhood (ca. 0.8–1.5 years of age). The results also indicate that an early onset of DDE constituted a risk for further episodes. These changes in DDE correspond to periods of increasingly intense contact between Aboriginal people and Europeans and with changes to government policy aimed at assimilating the indigenous population. Such policies had marked costs for childhood development. The lack, however, of a visible marker of initial contact demonstrates the importance of the intensity of and motives behind interactions between indigenous and colonial populations in determining the health consequences of colonial encounters. Am J Phys Anthropol, 2004. © 2004 Wiley‐Liss, Inc.
DC current voltage characteristics of silicone rubber filled with conductive carbon black
Authors: Zhang Jie , Feng Shengyu , Wang Xinqiang 
Published: August 2004

AbstractDirect current (DC) current‐voltage (I‐V) characteristics of silicone rubber filled with conductive carbon black (CB) were studied at room temperature in the voltage range of 1–46 V. The current‐voltage relationship can be expressed as I = AVB, where A and B are constants that show capability and property of electrical conduction, respectively. The I‐V curve can be divided into ohmic and nonohmic regions. In nonohmic region, B < 1, and the resistance increases with the rise of voltage. Higher CB loading leads to lower transforming voltage from ohmic to nonohmic region and much deviation from Ohm's law. The reason for this deviation is the unbalance between the heat generated and the heat loss of conductive silicone rubber during the measurement. When the heat effect is eliminated completely, the electrical conduction is ohmic. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 587–592, 2004
Generation of microcellular biodegradable polycaprolactone foams in supercritical carbon dioxide
Authors: Xu Qun , Ren Xianwen , Chang Yuning , Wang Jingwu , Yu Long , Dean Katherine 
Published: August 2004

AbstractMicrocellular foaming of low‐Tg biodegradable and biocompatible polycaprolactone (PCL) in supercritical CO2 has been studied. The purpose is to apply microcellular materials to drug containers and medical materials for artificial skin or bone. Effects of a series of variable factors on the foam structures, such as saturation temperature, saturation pressure, saturation time, and depressurization time were studied. The experimental results indicate that, while keeping other variables unchanged, higher saturation temperature leads to reduced bulk densities and different saturation pressures result in different nucleation processes. In addition, saturation time has a profound effect on the structure of the product. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 593–597, 2004
Thermal properties of hydrophobically modified methacrylic acid–ethyl acrylate copolymer solutions
Authors: Tam K. C. , Ng W. K. , Jenkins R. D. 
Published: August 2004

AbstractThe thermal behavior of a water‐soluble associating polymer system, hydrophobically modified alkali‐soluble emulsion (HASE) polymer, was investigated. This polymer contains a methacrylic acid–ethyl acrylate copolymer backbone with 1 mol % of pendant hydrophobic groups grafted to it. The thermal behavior of the HASE polymer exhibits different trends compared to the hydrophobic ethoxylated urethane (HEUR) system. The lifetime of the hydrophobic junction of the HASE polymer increases with temperature due to the increase in the entropy of the system. However, the structural relaxation time decreases with temperature, caused by the enhanced Brownian dynamics of polymer chains. The relaxation behavior of HASE polymers is either governed by the lifetime of the hydrophobic junction, the structural relaxation time, or a combination of both, depending on the degree of network formation and temperature. Temperature studies indicated that the transient network theory proposed by Tanaka and Edwards is inadequate for describing the activation process of hydrophobic junctions in the HASE associative polymer. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 604–612, 2004
Influence of turbulent mixing on fast polymerization reactions
Authors: Minsker Karl S. , Zakharov Vadim P. , Berlin Alexander Al. , Zaikov Gennadi E. 
Published: August 2004

AbstractInvestigations on development of a macrokinetics approach were generalized to the analysis of fast chemical reactions, mainly using cationic polymerization of isobutylene as an example, which is a new class of liquid‐phase processes. The removal of diffusional constraints on polymer synthesis, by intensification of turbulent mixing in the reaction zone, makes it possible to calculate the kinetic parameters of polymerization and polymer‐analogous reactions, to optimize the molecular characteristics of polymeric products obtained, and to control the character of the process as a whole. The laws pertaining to the progression of fast processes are considered for the synthesis of separate polymers, in particular stereoregular polydienes, ethylene–propylene copolymers, and chlorobutyl rubber. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 613–624, 2004
A gradient structure formed in injection‐molded polycarbonate in situ hybrid composites and its corresponding performances
Authors: Zhang Baoqing , Zhang Jun , He Jiasong 
Published: August 2004

AbstractThree polycarbonate (PC) composites that were reinforced, respectively, with liquid crystalline polymer (LCP), glass fibers, and both of them were prepared by a single injection‐molding process. The role of LCP in improving the processibility of the composites was characterized by torque measurement test. The transitions of LCP morphology in two‐ and three‐component composites were investigated by using polarizing optical microscopy and scanning electron microscopy. The micrographs showed a skin–core gradient structure in all three systems investigated, and the addition of glass fiber to the PC/LCP blend affected the morphological transition and content distribution of dispersed LCP phase through the thickness of the injection‐molded samples. These results were correlated well with the measurements of tensile mechanical properties and dynamic mechanical analysis. How to fully use the dispersed LCP phase in PC in situ hybrid composites was discussed for the thickness change of core layer and the heterogeneous distribution of more LCP in the core. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 625–634, 2004
Use of a methylolated softwood ammonium lignosulfonate as partial substitute of phenol in resol resins manufacture
Authors: Alonso M. V. , Oliet M. , Rodríguez F. , Astarloa G. , Echeverría J. M. 
Published: August 2004

AbstractThe synthesis of lignin‐phenol‐formaldehyde (LPF) was studied to determine its optimum operating conditions. The lignin proposed as phenol substitute has been the softwood ammonium lignosulfonate. The resin synthesis was optimized by varying the methylolated lignosulfonate content, 18–52%; the sodium hydroxide to phenol‐modified lignosulfonate molar ratio, 0.3–0.94; and the formaldehyde to phenol‐modified lignosulfonate molar ratio, 1.1–3.5. The parameters employed in the characterization of LPF resins were free phenol, free formaldehyde, gel time, alkaline number, viscosity, pH, solid content, and chemical structure changes. The properties of LPF resin comply with the requirements for its utilization in plywood manufacture. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 643–650, 2004
On the modeling of the dynamic‐elastic modulus for polymer materials under isochronal conditions
Authors: Reyes‐Melo E. , Martínez‐Vega J. , Guerrero‐Salazar C. , Ortiz‐Méndez U. 
Published: August 2004

AbstractA model based on the concept of fractional calculus is proposed for the description of the dynamic elastic modulus, E* = E′ + iE″, of polymer materials. This model takes into account three relaxation phenomena (α, β, and γ) under isochronal conditions. The differential equations obtained for this model have derivatives of fractional order between 0 and 1. Applying the Fourier transform to the fractional differential equations and associating each relaxation mode to cooperative or noncooperative movements, E*(iω,T) was evaluated. The isochronal diagrams of E′ and E″ clearly show three relaxation phenomena, each of them is manifested by a decrease of E′ when temperature increases. This decrease is associated with a maximum in E″(T) diagram for each relaxation mode. The shape of the three peaks (three maxima in E″(T) diagrams) depends of the fractional orders of this new fractional model. The mathematical description obtained of E* corresponds to a nonexponential relaxation behavior often encountered in the dynamics of polymer systems having three relaxation phenomena. This model will enable us to analyze the viscoelastic behavior of polymers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 657–670, 2004
Crystallinity and oxygen transport properties of PET bottle walls
Authors: Liu R. Y. F. , Hu Y. S. , Schiraldi D. A. , Hiltner A. , Baer E. 
Published: August 2004

AbstractOxygen transport was coupled with other methods to study the relationship of gas barrier to solid state structure in the PET blown bottle wall. Commercial 2‐L carbonated soft drink bottles blown under different process conditions were studied. Crystallinity determinations from heat of melting, density, glycol trans fraction, and oxygen solubility were compared. The reasons for lack of correlation between conventional crystallinity methods based on heat of melting and density were elucidated, and neither was found to be reliable. An alternative approach to determining crystallinity based on oxygen solubility gave reliable results and revealed fundamental characteristics of the amorphous phase, such as amorphous phase density and amorphous phase oxygen solubility. Dedensification of the amorphous phase was responsible for higher oxygen permeability of bottle walls processed under conditions of higher thermal exposure (temperature/time) despite the parallel increase in volume fraction of impermeable crystals. The strong dependence of dedensification on process temperature was explained in terms of the temperature–volume relationship of the amorphous phase. A low process temperature minimized amorphous phase dedensification and delivered a bottle wall with the best oxygen barrier. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 671–677, 2004
Carbon black effect on the acoustic properties of nitrile butadiene rubber
Authors: Jung Kyung‐Il , Yoon Suk Wang , Sung Shi‐Joon , Park Jung‐Ki 
Published: August 2004

AbstractAcoustic and mechanical properties of nitrile butadiene rubbers (NBR) with the variation of the carbon black contents were investigated. All the composition contents except carbon black were kept constant in the specimens. Acoustic measurements were performed in the frequency range of 300–800 kHz. Increase of the carbon black contents in the rubber resulted in an increase of the mechanical properties such as density, hardness, tensile strength, and glass transition temperature. The sound speed and attenuation in the specimen were mainly affected by the carbon black. The sound speed increased with the carbon black content and depended on the square root of the ratio of hardness to density. However, the sound attenuation was not affected by the carbon black content variation but by the existence of the carbon black. The results with carbon black content variation were also compared with those of the sulfur content variation having a fixed carbon black content (K. I. Jung et al., J Appl Polym Sci 85, 2764–2771, 2002). These results show that the variation of acoustic properties can be used to nondestructively evaluate mechanical properties and to estimate the carbon black content variation in NBR. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 678–683, 2004
Effect of hydrotalcite on the physical properties and drug‐release behavior of nanocomposite hydrogels based on poly[acrylic acid‐co‐poly(ethylene glycol) methyl ether acrylate] gels
Authors: Lee Wen‐Fu , Chen Yung‐Chu 
Published: August 2004

AbstractA series of nanocomposite hydrogels used for bioadhesive were prepared from acrylic acid, poly(ethylene glycol) methyl ether acrylate, and intercalated hydrotalcite (HT) by photopolymerization. The microstructures of the intercalated HT and sample gels were identified by X‐ray diffraction (XRD). The results showed that the swelling ratio for these nanocomposite hydrogels increased with an increase in HT, but the gel strength and adhesive force for these gels decreased with an increase in HT. The XRD results indicated that the exfoliation of intercalated HT was achieved in the xerogels and swollen gels. Finally, the drug‐release behaviors for these gels were also examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 692–699, 2004
Study on pancreatic lymphatics in nonobese diabetic mouse with prevention of insulitis and diabetes by adjuvant immunotherapy
Authors: Qu Peng , Ji Rui‐Cheng , Shimoda Hiroshi , Miura Masahiro , Kato Seiji 
Published: August 2004

AbstractThe present study has investigated the relationship between pancreatic lymphatics, infiltrating cells, and insulitic development after a single injection of complete Freund's adjuvant (CFA) given at an early age in the nonobese diabetic (NOD) mice. No CFA‐treated NOD mice developed hyperglycemia, whereas most CFA‐untreated mice died of diabetes at the age of 20–30 weeks. In untreated NOD mice, the increased infiltration of dendritic cells (DCs) and T‐lymphocytes into the pancreatic islets appeared to be consistent with the increased expression of the secondary lymphoid chemokine (CCL21) and CD31 by the endothelial cell lining of inter‐ and intralobular lymphatics. As the infiltration became severe, the reaction products of CCL21 and CD31 were distributed in the nucleus and cytoplasm of lymphatic endothelial cells (LECs), through which DCs and T‐lymphocytes migrated frequently. Administration of CFA reduced the number of infiltrating DCs and T‐lymphocytes, but did not affect macrophage infiltration. The peri‐insulitis occurred in numerous islets of CFA‐treated NOD mice without the appearance of the intraislet infiltration and islet‐associated lymphoid‐like tissues. Furthermore, significant suppression of CCL21 and CD31 was demonstrated on the infiltrating cells to the islets and islet‐associated lymphatics. The abluminal endothelial cell lining of lymphatic vessels exhibited weaker immunoreactivity of CCL21 and CD31 in comparison with the luminal surfaces. The reaction product of 5′‐nucleotidase (5′‐Nase) was evenly deposited on LECs, which were the absence of open junctions, cytoplasmic protrusions, and vesicles. CFA treatment influenced the migratory processes of the infiltrating cell, which were closely related with structural changes of pancreatic lymphatics and inhibited insulitic development. These findings suggest that in CFA‐treated NOD mice, the suppression of insulitis and prevention of diabetes are secondary to the functional modulation of pancreatic lymphatics and infiltrating cells. © 2004 Wiley‐Liss, Inc.
Immunohistochemical localization of periostin in tooth and its surrounding tissues in mouse mandibles during development
Authors: Suzuki Hironobu , Amizuka Norio , Kii Isao , Kawano Yoshiro , Nozawa‐Inoue Kayoko , Suzuki Akiko , Yoshie Hiromasa , Kudo Akira , Maeda Takeyasu 
Published: August 2004

AbstractPrevious reports have shown expression of immunoreactivity for periostin, originally identified as osteoblast‐specific factor‐2, in the periosteum and periodontal ligament. However, the developmental changes in its expression and the detailed immunolocalization have remained veiled. The present study was undertaken to examine the spatiotemporal expression of this protein in teeth and their associated tissues of mice during development at light and electron microscopic levels. In tooth germs at cap stage, periostin immunoreactivity was recognizable in the interface between inner enamel epithelium and preodontoblasts as well as in the mesenchymal tissues around cervical loop. Dental follicles around tooth germs at bell stage localized periostin immunopositivity in addition to the immunopositive areas observed in cap‐staged tooth germs, although the functional significance of periostin has remained unclear in tooth development. Furthermore, periostin immunoreactivity was also found in the alveolar bone surface. In the incisors of both 7‐ and 21‐day‐old mice, immunoreaction for periostin was discernible in the lingual periodontal ligament and labial fibrous tissue adjacent to the papillary layer. After postnatal day 7, immunoreaction for periostin came to be restricted to the fibrous bundles in the periodontal ligament in accordance with the organization of the periodontal fibers, indicating its localization matched the morphogenesis of the periodontal ligament. Immunoelectron microscopic observation of the mature periodontal ligament verified the localization of periostin between the cytoplasmic processes of periodontal fibroblasts and cementoblasts and the adjacent collagen fibrils. Our findings suggest that periostin is involved at the sites of the cell‐to‐matrix interaction, serving as adhesive equipment for bearing mechanical forces, including occlusal force and tooth eruption. © 2004 Wiley‐Liss, Inc.