bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interface development and encapsulation in simultaneous coinjection molding of disk. II. Two‐dimensional simulation and experiment
Authors: Li C. T. , Lee D. J. , Isayev A. I. 
Published: March 2003

AbstractTwo‐dimensional simulation and experimental studies of flow‐rate‐controlled coinjection molding were carried out. Skin polymer was injected first, and then both skin and core polymers were injected simultaneously into a center‐gated disk cavity through a two‐channel nozzle to obtain an encapsulated sandwich structure. The physical modeling and simulation developed, reported in Part I of this series, were based on the Hele–Shaw approximation and the kinematics of the interface to describe the multilayer flow, and the interface development was used to predict the skin/core distribution in the moldings. The effects of rheological properties and processing conditions on the material distribution, penetration behavior, and breakthrough phenomena were investigated. The predicted and measured results were found to be in a good agreement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2310–2318, 2003
Organic–inorganic polymer hybrids and porous materials obtained on their basis
Authors: Cazacu Maria , Dragan Stela , Vlad Angelica 
Published: March 2003

AbstractTetramethoxysilane (TMOS) or tetraethoxysilane (TEOS), an organic monomer [methylmethacrylate (MMA) or styrene (St)] and either α‐propylmethacryloxy‐ω‐trimethylsiloxy‐oligo(dimethylsiloxane) (OMS), as a compatibilizing agent, or α,ω‐bis(vinyl) oligo(dimethylsiloxane) (OVS), as compatibilizing and crosslinking agent, were allowed to undergo a sol–gel reaction under acidic condition and in the presence of 2,2′‐azoisobutyronitrile (AIBN) as a free‐radical initiator. The hydrolysis‐condensation and in situ free‐radical polymerization occur independently, to give a hybrid consisting of both inorganic and organic components. The conversion of the monomers to the proper polymers was monitored by IR spectroscopy and TGA. The resistance of the organic polymers to solvent extraction was also studied. The hybrids were pyrolyzed in an oxidative atmosphere. By decomposition, the organic polymer generated pores in the inorganic matrix. A quantitative evaluation of the characteristics for the resulting porous material was made by determination of the specific area, pore volume, and average radius. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2060–2067, 2003
Preparation of novel gold‐coated syndiotactic poly(vinyl alcohol) microfibrils by sputtering
Authors: Do Ghim Han , Pil Kim Jae , Ho Kim Joon , Koo Kang , Soo Kim Sam , Seok Lyoo Won 
Published: March 2003

AbstractTo prepare a syndiotactic poly(vinyl alcohol) (PVA)/gold complex for various biomedical applications, ultrahigh‐molecular‐weight syndiotactic PVA microfibrils were directly prepared by the saponification of poly(vinyl pivalate) that was obtained through bulk polymerization of vinyl pivalate at 30°C. PVA microfibrils with a number‐average degree of polymerization, syndiotactic diad content, and degree of saponification of 14,300, 61.7%, and 99.9%, respectively, were gold‐coated by sputtering at 140 and 150 W (Watt) for 1, 2, and 3 min, respectively. A weight gain of up to 7% by the gold atoms for the PVA microfibrils treated at 150 W for 3 min was found. Morphological changes at the surface were observed by a microscopic method. A mechanism of gold coating on PVA microfibrils is suggested. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2369–2372, 2003
Silicone elastomers for electronic applications. I. Analyses of the noncrosslinked fractions
Authors: Andersson L. H. U. , Hjertberg T. 
Published: March 2003

AbstractIn a study about silicone contamination on surfaces, crosslinked polydimethylsiloxanes have been examined focusing on the curing process and the noncrosslinked part in the bulk of the material. Curing was studied by following the development of gel as a function of curing time and temperature using Soxhlet extraction and differential scanning calorimetry (DSC) measurements. Gas chromatography–mass spectroscopy (GC‐MS), size exclusion chromatography (SEC), and thermogravimetric analysis (TGA) analyses gave information about the composition and size of the noncrosslinked fraction. The experiments demonstrate that the curing kinetics are of Arrhenius type with a strong temperature dependence. Interestingly, we find that 5–20% of the material does not undergo crosslinking reactions, although only 0–1% of the total sample mass is volatile at ambient temperature and pressure. It is likely that the volatile components mainly give rise to problems when they are confined to closed compartments or when they are in direct contact with a cold surface so that condensation on the surface occurs. Most likely, surface contamination originates from the nonvolatile fraction of the noncrosslinked portion of the material. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2073–2081, 2003
The nutrient status of the agriculturally impacted Gamtoos Estuary, South Africa, with special reference to the river‐estuarine interface region (REI)
Authors: Scharler U.M. , Baird D. 
Published: March 2003

Abstract
Ecological water reserves are part of the new water management philosophy in South Africa. The estuaries are threatened by excessive water abstraction from their rivers and the consequent reduction in freshwater input. This study was conducted to further improve our understanding of freshwater requirements in terms of nutrients for South African estuaries.
The Gamtoos Estuary was sampled between November 1996 and November 1998 to determine its nutrient status and freshwater input rates. Furthermore, the possible existence of a distinct river‐estuarine interface (REI) in terms of nutrients has been investigated. Nutrients analysed included phosphate, nitrate, nitrite, ammonia, dissolved organic nitrogen (DON), dissolved organic carbon (DOC), particulate organic nitrogen (PON) as Kjieldahl nitrogen, total particulate phosphorus and total particulate carbon.
The Gamtoos River was found not to be the ultimate source of nutrients to the estuary, but non‐point sources such as the seepage of fertilisers from adjacent agricultural fields determined to a great extent the nutrient status of the estuary.
Results showed that it was not possible to identify a defined river‐estuarine interface region for all nutrients. Most were measured in higher concentrations in the lower salinity reaches (<17‰) where we observed the combined effect of inputs from the Gamtoos River, an agricultural drainage pipe, and fertilizer seepage from non‐point sources on nutrient concentration.
Prolonged water withdrawal for human use impacts the continuous renewal of the nutrient pool so important to other South African estuaries with relative pristine catchment areas. However, reduced fresh water inputs could enhance eutrophication in polluted estuaries due to a decreased flushing potential of the estuary. In this case the Gamtoos Estuary has a freshwater requirement for freshets and floods to “clean” the estuary of accumulated nutrients and other organic material.
This should be a consideration in further freshwater abstraction policies. Conservation issues arise since the Gamtoos Estuary is one of the few permanently open estuaries along the South African coast and serve in this study as an example and as a first attempt to relate freshwater requirements to nutrient dynamics in a South African context.
Copyright © 2002 John Wiley & Sons, Ltd.
Quantification of serpulid biogenic reef coverage of the sea bed (Polychaeta: Serpulidae) using a video transect technique
Authors: Moore Colin G. , Harries Dan B. , Lyndon Alastair R. , Saunders Graham R. , Conway Terence R. 
Published: March 2003

Abstract
The large size, patchiness and fragility of serpulid reefs present difficulties for the measurement of reef coverage for mapping and monitoring studies. Video transect measures of cover are assessed in terms of accuracy and sensitivity of the method for the identification of spatial or temporal changes.
By comparison with direct in situ measurement of reef cover, it was found that still photography was capable of providing an accurate means for the measurement of the seabed coverage by individual reefs.
By comparison of video and still photographic measurement of reef cover, it was found that video transects were capable of providing cover estimates of sufficient accuracy for conservation purposes, differing from still photographic estimates by 0.3% cover.
Power analysis was employed on replicate video estimates of reef cover in order to determine the degree of replication required to identify different levels of spatial or temporal change in cover using video transects of different lengths. The modest level of replication required to identify changes in coverage as small as 25% of the initial value suggests that the use of video transects offers great potential in monitoring and mapping studies.
Copyright © 2002 John Wiley & Sons, Ltd.
Inhibition of the cardiac α‐actin gene in embryonic cardiac myocytes by dominant‐negative serum response factor
Authors: Zhu Xiaolei , McAllister Donna , Lough John 
Published: March 2003

AbstractSerum response factor (SRF), a transcription factor ubiquitously involved in the processes of cellular proliferation and differentiation, has been implicated in cardiac and skeletal muscle development because of its strong expression in embryonic muscle lineages, and its necessity for the transcription of transiently transfected muscle genes that contain SRF binding sites. This study was designed to ascertain whether SRF is required for the expression of an endogenous SRF‐dependent gene during differentiation of early embryonic cardiac myocytes by introducing a dominant‐negative SRF construct via retroviral delivery. Although no effect on overt cellular differentiation was detected, semi‐quantitative RT‐PCR revealed that expression of the SRF‐dependent gene cardiac α‐actin was inhibited, whereas expression of the non‐SRF‐dependent genes glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) and cardiac troponin‐C was unaffected. No effect on myocyte proliferation was detected. Curiously, immunohistochemical localization of SRF protein suggested that whereas endogenous SRF was homogeneously dispersed throughout the cytoplasm and nucleus, the dominant‐negative SRF protein was concentrated in the nucleus. These results extend previous findings using transiently transfected genes to the endogenous level, indicating that SRF is required for the full expression of muscle genes that contain SRF binding sites during cardiac myocyte differentiation. Anat Rec Part A 271A:315–321, 2003. © 2003 Wiley‐Liss, Inc.
Frontonasal dysplasia in 3H1 Br/Br mice
Authors: McBratney Brandeis M. , Margaryan Edith , Ma Wenbin , Urban Zsolt , Lozanoff Scott 
Published: March 2003

AbstractThe adult Brachyrrhine (3H1 Br/+) mouse displays severe midfacial retrognathia, with a “pugnose” external appearance, but information concerning craniofacial morphology of the homozygote (3H1 Br/Br) mutant is lacking. This study characterized craniofacial phenotype and genotypic features of the homozygous condition. Segregation analysis was performed by phenotypic scoring of offspring from 3H1 Br/+ reciprocal matings. Whole‐mount staining was undertaken to determine the presence or absence of cranial base structures in newborn and adult mice, while features of cranial base chondrification were examined using light microscopy and type II collagen immunohistochemistry. Karyotype analysis was performed to determine whether gross chromosomal aberrations were present. Finally, microsatellite mapping analysis was undertaken to provide further resolution of the Br locus. Results showed that Br was inherited as an autosomal semidominant feature. 3H1 Br/Br mice consistently lacked a presphenoid (with its lateral projections, including a preoptic root, postoptic root, and lesser wing). Karyotyping did not reveal major gross aberrations; however, microsatellite analysis localized Br to distal mouse chromosome 17 in the vicinity of D17Mit155. These results indicated that 3H1 Br/Br mice show characteristic features of frontonasal dysplasia, including median facial clefting and bifid cranium, as well sphenoidal malformations. Furthermore, this mutant should serve as a useful model for examining mechanisms of frontonasal dysplasia. Anat Rec Part A 271A:291–302, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructural morphometry of capillary basement membrane thickness in normal and transgenic diabetic mice
Authors: Carlson Edward C. , Audette Janice L. , Veitenheimer Nicole J. , Risan Jessica A. , Laturnus Donna I. , Epstein Paul N. 
Published: March 2003

AbstractCapillary basement membrane (CBM) thickening is an ultrastructural hallmark in diabetic patients and in animal models of diabetes. However, the wide variety of tissues sampled and diverse methods employed have made the interpretation of thickness data difficult. We showed previously that acellular glomerular BMs in OVE26 transgenic diabetic mice were thickened beyond normal age‐related thickening, and in the current study we hypothesized that other microvascular BMs likewise would show increased widths relative to age‐matched controls. Accordingly, a series of tissues, including skeletal and cardiac muscle, ocular retina and choriod, peripheral nerve, lung, pancreas, and renal glomerulus was collected from 300–350‐day‐old normal and transgenic mice. Transmission electron micrographs of cross sections through capillary walls were prepared, and CBM thickness (CBMT) was determined by the “orthogonal intercept” method. Morphometric analyses showed highly variable transgene‐related BMT increases in the sampled tissues, with glomerular BM showing by far the greatest increase (+87%). Significant thickness increases were also seen in the retina, pulmonary alveolus, and thoracoabdominal diaphragm. BMT increases were not universal; however, most were modestly widened, and those that were thickest in controls generally showed the greatest increase. Although the pathogenesis of diabetes‐related increases in CBM is poorly understood, data in the current study showed that in OVE26 transgenic mice increased BMT was a frequent concomitant of hyperglycemia. Accordingly, it seems likely that hyperglycemia‐induced microvascular damage may be a contributing factor in diabetic BM disease, and that microvessel cellular and extracellular heterogeneity may limit the extent of CBM thickening in diverse tissues. Anat Rec Part A 271A:332–341, 2003. © 2003 Wiley‐Liss, Inc.
Ultrastructure indicative of ion transport in tectal, Deiters, and tunnel cells: Differences between gerbil and chinchilla basal and apical cochlea
Authors: Spicer Samuel S. , Smythe Nancy , Schulte Bradley A. 
Published: March 2003

AbstractUltrastructural examination revealed an epithelium of about five tectal cells (TCs) roofing the outer tunnel (OT) in the mid to upper, but not the basal, region of gerbil and chinchilla cochlea. Structures in TCs that are apparently specialized for retrieval of K+ released into tunnel fluid from outer hair cells (OHCs) include surface fimbriae in the gerbil and canalicular reticulum in the chinchilla. A tunnel roof of organelle‐rich TCs appeared to be better equipped for ion resorption than a roof composed of organelle‐poor Hensen cells (HCs). Fimbriae, filopodia, and the cell body of TCs descended to contact the third Deiters cell (DC3) in the gerbil, and the hypertrophied DC3 phalanx rose to contact TCs in the chinchilla, which suggests a solute exchange between TCs and DCs. Previously unrecognized structures that are speculated to provide ATP ligand for cochlear purinoreceptors occurred in the chinchilla DC and gerbil TC. The observation of a microtubule stalk in DCs indicated that they also function in cochlear mechanics. A newly delineated lateral tunnel cell (LTC) intervened between the DC3 and HC in both species. The apicomedial plasmalemma of all DCs fitted closely to the base of OHCs and enveloped afferent nerves. The morphologic specializations reported here provide further support for the proposed transcellular lateral flow route for K+ currents generated by sound exposure and neural activity. The previously demonstrated expansion of Boettcher cells, outer sulcus cell roots, type Il and IV fibrocytes, and apical microvilli on HCs and Claudius cells (CCs) in the base of the cochlea is postulated here to mediate a basal parallel current that could supply the increased K+ transport required for the basally elevated electric potential (EP). Anat Rec Part A 271A:342–359, 2003. © 2003 Wiley‐Liss, Inc.
Ectodysplasin receptor‐mediated signaling is essential for embryonic submandibular salivary gland development
Authors: Jaskoll Tina , Zhou Yan‐Min , Trump Gary , Melnick Michael 
Published: March 2003

AbstractHypohidrotic (anhidrotic) ectodermal dysplasia (HED), the most common of the ∼150 described ectodermal dysplasias, is a disorder characterized by abnormal hair, teeth, sweat glands, and salivary glands. Mutations in the EDA (ectodysplasin‐A) and EDAR (ectodysplasin‐A receptor) genes are responsible for X‐linked and autosomal HED, respectively. Abnormal phenotypes similar to HED are seen in Tabby (EdaTa) and downless (Edardl) mutant mice. Although recent studies have focused on the role of Eda/Edar signaling during hair and tooth development, very little is known about its role during embryonic submandibular salivary gland (SMG) development. To this end, we analyzed the SMG phenotypes in Tabby (Ta) and downless (dl) mutant mice and determined that Ta SMGs are hypoplastic, whereas dl SMGs are severely dysplastic. The absence of SMG ducts and acini in dl SMGs suggests that Eda/Edar signaling is essential for lumina formation and glandular histodifferentiation. Our localization of Eda and Edar proteins at sites of lumen and acini formation supports this conclusion. Moreover, the presence of SMGs in both Ta and dl mutant mice, as well as the absence of immunodetectable Eda and Edar protein in Initial Bud and Early Pseudoglandular stage SMGs, indicate that Eda/Edar‐mediated signaling is important for branching morphogenesis and histodifferentiation, but not for initial gland formation. To initially delineate the morphoregulatory role of Eda/Edar‐mediated signaling during embryonic SMG development, we cultured embryonic day 14 SMGs with enhanced or abrogated Eda/Edar signaling. Eda supplementation induced a significant increase in SMG branching, and enhanced activation of NF‐κB. Abrogating Eda/Edar signaling by adding the soluble form of Edar to bind endogenous ligand in embryonic SMGs results in a significant dose‐dependent decrease in branching morphogenesis. Taken together, our results suggest that the Eda/Edar/NF‐κB pathway exerts its effect on SMG epithelial cell proliferation, lumina formation, and histodifferentiation. Anat Rec Part A 271A:322–331, 2003. © 2003 Wiley‐Liss, Inc.
Variability of Broca's area homologue in African great apes: Implications for language evolution
Authors: Sherwood Chet C. , Broadfield Douglas C. , Holloway Ralph L. , Gannon Patrick J. , Hof Patrick R. 
Published: March 2003

AbstractThe cortical circuits subserving neural processing of human language are localized to the inferior frontal operculum and the posterior perisylvian region. Functional language dominance has been related to anatomical asymmetry of Broca's area and the planum temporale. The evolutionary history of these asymmetric patterns, however, remains obscure. Although testing of hypotheses about the evolution of language areas requires comparison to homologous regions in the brains of our closest living relatives, the great apes, to date little is known about normal interindividual variation of these regions in this group. Here we focus on Brodmann's area 44 in African great apes (Pan troglodytes and Gorilla gorilla). This area corresponds to the pars opercularis of the inferior frontal gyrus (IFG), and has been shown to exhibit both gross and cytoarchitectural asymmetries in humans. We calculated frequencies of sulcal variations and mapped the distribution of cytoarchitectural area 44 to determine whether its boundaries occurred at consistent macrostructural landmarks. A considerable amount of variation was found in the distribution of the inferior frontal sulci among great ape brains. The inferior precentral sulcus in particular was often bifurcated, which made it impossible to determine the posterior boundary of the pars opercularis. In addition, the distribution of Brodmann's area 44 showed very little correspondence to surface anatomy. We conclude that gross morphologic patterns do not offer substantive landmarks for the measurement of Brodmann's area 44 in great apes. Whether or not Broca's area homologue of great apes exhibits humanlike asymmetry can only be resolved through further analyses of microstructural components. Anat Rec Part A 271A:276–285, 2003. © 2003 Wiley‐Liss, Inc.
A clinician's view of spinal cord injury
Authors: Harkey H.Louis , White Elbert A. , Tibbs Robert E. , Haines Duane E. 
Published: March 2003

AbstractThe primary cause of spinal cord injury (SCI) is automobile collisions, followed by violence, falls, and injuries in sporting events. The patient is most frequently a young male. Regardless of cause and age, SCI is a potentially catastrophic injury. The unique anatomical relationship of the spinal cord, being enclosed in the dural sac within the bony vertebral column, make it venerable to a wide range of traumatic insults. SCI is classified as complete or incomplete with several subclasses arranged under each of these respective headings. The probability of recovery to a functional state is usually better for patients with incomplete injuries. Treatment for SCI involves initially immobilizing the injured vertebral column, medications to prevent secondary injury, and potential surgery to release pressure on the spinal cord and restore stability to the vertebral column. Postsurgical care is directed toward prevention and treatment of secondary complications of SCI such as respiratory failure, deep venous thrombosis, and decubitus ulcers. Advances in these areas are providing patients with a greater probability of recovery, a longer life, and a better quality of life. Research in the clinical and basic sciences is opening new avenues of hope for the spinal cord injury patient. Anat Rec (Part B: New Anat) 271BB:41–48, 2003. © 2003 Wiley‐Liss, Inc.
Use of a cell line to investigate olfactory ensheathing cell‐enhanced axonal regeneration
Authors: DeLucia Tracey A. , Conners James J. , Brown Todd J. , Cronin Colleen M. , Khan Talat , Jones Kathryn J. 
Published: March 2003

AbstractOlfactory ensheathing cells (OECs), a unique type of macroglia required for normal olfactory axonal regeneration throughout the lifetime of an individual, have been shown to have regeneration‐enhancing properties when used to treat various neuronal injuries. Availability of OECs is a hurdle facing future clinical use of the cells for spinal cord injury (SCI) therapy. The number of OECs that can realistically be harvested from each animal is limited, and ensuring a pure cell population is difficult. We have begun to characterize a nonsyngeneic strain of OECs, i.e., from a homogenous OEC clonal cell line (nOECs). The purpose of this study was to determine whether nOECs have the same properties and provide the same functional recovery after SCI, as primary cultures of OECs. The results indicate that nOECs survive in vivo, produce growth‐promoting proteins, and possess regeneration‐promoting capabilities. Spinal cord injured rats that were treated with nOECs performed significantly better on functional tests than injured control animals beginning at 5 weeks after operation. In summary, evidence of nOEC regeneration‐promoting capabilities suggests that this cell line can be used as potential therapy in SCI research. Anat Rec (Part B: New Anat) 271B:61–70, 2003. © 2003 Wiley‐Liss, Inc.