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Selected AbstractsPreparation of poly(ester imide) ultrafine fibers by gas-jet/electrospinningJOURNAL OF APPLIED POLYMER SCIENCE, Issue 2 2009Bing Wang Abstract In this study, ultrafine fibers of poly(ester imide) (PEI) were produced by gas-jet/electrospinning of its solutions in mixtures of phenol and dichloromethane (DCM). The process parameters, including the solution concentration, gas flow rate, applied voltage, tip-to-collector distance (TCD), and inner diameter of the metal needle, were investigated by scanning electron microscopy. The results show that the solution concentration, gas flow rate, TCD, and inner diameter of the needle were the most important process parameters influencing the average diameter and morphology of the PEI gas-jet/electrospun fibers. An increase in the solution concentration resulted in a larger average diameter in the PEI gas-jet/electrospun fibers. Mixed-bead fibers were obtained when the concentration of PEI in phenol/DCM was below 20 wt % during gas-jet/electrospinning. A larger diameter of the capillary and a smaller gas flow rate favored the formation of ultrafine fibers with thicker fibers. Thinner and uniform PEI fibers with an average diameter of 298 nm were formed at a TCD of 25 cm. On the basis of the systematic parameters study, uniform PEI ultrafine fibers with an average diameter of 293 nm were prepared by this gas-jet/electrospinning with the following optimal process parameters: the concentration of the polymer solution was 20 wt %, the gas flow rate was 10.0 L/min, the applied voltage was 25.0 kV, the TCD was 25 cm, and the inner diameter of the metal needle was 0.24 mm. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 [source] Morphological and immunohistochemical studies on cleft palates induced by 2,3,7,8-tetrachlorodibenzo- p -dioxin in miceCONGENITAL ANOMALIES, Issue 2 2008Kumiko Fujiwara ABSTRACT Morphological and immunohistological examinations were performed to reveal the mechanisms of cleft palate induction by 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD). ICR strain mice 8,10 weeks of age were used in the study. TCDD was administered in olive oil on gestation day (GD) 12.5 with gastric tubes at 40 ,g/kg. From GD 13.5 to 16.5, palates were examined by scanning electron microscopy (SEM), hematoxyline,eosin (HE) staining, and immunohistochemical staining of FGFR1/2, TGF-,3, MSX1 and LHX8. In the control group, both of the palatal shelves began elevating on GD 14.0 and finished within 6 h. After the elevation, all of the shelves had completely fused with each other on GD 14.5. In the TCDD-treated group, palatal shelves elevated 1 day later than in the control group. However, all palates had elevated by GD 15.0. After the elevation, the shelves contacted each other and fused; however, they were separated on GD16.0. HE staining showed that medial edge epithelium (MEE) was thinner in the TCDD group than in the control group. MEE observed under a high magnification (×2500) exhibited filopodia-like filaments and the cells were bulged in the control group. In contrast, in the TCDD group, no filaments were observed and the cells were flat with unclear boundaries. Immunohistologically, there were no characteristic findings except for FGFR1. FGFR1 was not expressed in the TCDD group after the fusion phase (GD 14.5). TCDD induces many morphological and molecular changes to MEE cells and causes cleft palates. [source] Disruption of brain development in male rats exposed prenatally to 5-bromo-2,-deoxyuridineCONGENITAL ANOMALIES, Issue 4 2001Makiko Kuwagata ABSTRACT, Sprague-Dawley rats were treated intraperitoneally with 5-bromo-2,-deoxyuridine (BrdU) at 0,12.5 or 50 mg/kg/day on days 9 through 15 of gestation to evaluate the effects on development of the brain of offspring. Prenatal exposure to BrdU induced abnormal development of the brain; dilatation of the lateral ventricles in male offspring in the postnatal period. The ratio of the length of the longitudinal fissure to that of the cerebral cortex decreased in a dose-dependent manner in the embryonic period and thereafter. In 14-week-old male offspring exposed prenatally to BrdU at 50 mg/kg, the cortex layer of the cerebrum was thinner than that of the controls. Masculine sexual behavior was markedly impaired and the volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) was decreased in the 50 mg/kg group as compared with the controls. These results demonstrate that prenatal exposure to BrdU affected the development of the brain hi the prenatal and postnatal stages and reduced the volume of SDN-POA after puberty, resulting in a disruption of reproductive ability in male rats. [source] In Vivo Follicular Unit Multiplication: Is It Possible to Harvest an Unlimited Donor Supply?DERMATOLOGIC SURGERY, Issue 11 2006ERGIN ER MD BACKGROUND Follicular unit extraction is a process of removing one follicular unit at a time from the donor region. The most important limitation of this surgical procedure is a high transection rate. OBJECTIVE In this clinical study, we have transplanted different parts of transected hair follicle by harvesting with the follicular unit extraction technique (FUE) in five male patients. MATERIALS AND METHODS In each patient, three boxes of 1 cm2 are marked at both donor and recipient sites. The proximal one-third, one-half, and two-thirds of 15 hair follicles are extracted from each defined box and transplanted in recipient boxes. The density is determined at 12 months after the procedure. RESULTS A mean of 3 (range, 2,4) of the proximal one-third, 4.4 (range, 2,6) of the proximal one-half, and 6.2 (range, 5,8) of the proximal two-thirds of the transplanted follicles were observed as fully grown after 1 year. At the donor site, the regrowth rate was a mean of 12.6 (range, 10,14) of the proximal one-third, 10.2 (range, 8,13) of the proximal one-half, and 8 (range, 7,12) of the proximal two-thirds, respectively. CONCLUSION The survival rate of the transected hair follicles is directly related to the level of transection. Even the transected parts, however, can survive at the recipient site; the growth rate is not satisfactory and they are thinner than the original follicles. We therefore recommend that the surgeon not transplant the sectioned parts and be careful with the patients whose transection rate is high during FUE procedures. [source] Absence of tissue inhibitor of metalloproteinases 3 disrupts alveologenesis in the mouseDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 1 2009Sean E. Gill Tissue inhibitors of metalloproteinases (TIMPs) regulate extracellular matrix (ECM) degradation by matrix metalloproteinases (MMPs) throughout lung development. We examined lungs from TIMP3 null mice and found significant air space enlargement compared with wild type (WT) animals during a time course spanning early alveologenesis (post-partum days 1, 5, 9 and 14). Trichrome staining revealed a similar pattern of collagen distribution in the walls of nascent alveoli; however, the alveolar walls of TIMP3 mutant mice appeared to be thinner than controls. Assessment of MMP2 and MMP9 activities by gelatin zymography demonstrated a significant elevation in the active form of MMP2 at post-partum days 1 and 5. Treatment of null pregnant dams with a broad spectrum synthetic metalloproteinase inhibitor, GM6001, on embryonic day 16.5 enhanced the formation of primitive alveoli during the saccular stage of lung development as evidenced by a partial, but significant, rescue of alveolar size in post-partum day 1 animals. We propose that increased MMP activity in the absence of TIMP3 enhances ECM proteolysis, upsetting proper formation of primitive alveolar septa during the saccular stage of alveologenesis. Therefore, TIMP3 indirectly regulates alveolar formation in the mouse. To our knowledge, ours is the first study to demonstrate that in utero manipulation of the TIMP/MMP proteolytic axis, to specifically inhibit proteolysis, significantly affects lung development. [source] The proto-oncogene BCL6 promotes survival of olfactory sensory neuronsDEVELOPMENTAL NEUROBIOLOGY, Issue 6 2010Joji M. Otaki Abstract For the mammalian olfactory epithelium to continually detect odorant, neuronal survival, apoptosis, and regeneration must be coordinated. Here, we showed that the proto-oncogene BCL6, which encodes a transcriptional repressor required for lymphocyte terminal differentiation, contributes to the survival of olfactory sensory neurons (OSNs). In the olfactory epithelia of the BCL6 null mutant mice, many OSNs were positive for both OMP and GAP43. The epithelium was relatively thinner, showing many apoptotic signals. These characters were phenotypically similar to those of the wild-type mice treated with nasal lectin irrigation, which acutely induces apoptosis of OSNs. Odorant receptors were expressed normally in the epithelia of the mutant mice, and their overall expression profile based on DNA microarray analyses was roughly similar to that of the apoptosis-induced olfactory epithelia of the wild-type mice. Experimental increase of BCL6 together with green fluorescent protein in OSNs using adenovirus-mediated gene transfer made the epifluorescence last longer than the control fluorescence without exogenous BCL6 after the nasal lectin irrigation, indicating that BCL6 made the infected neurons survive longer. We conclude that BCL6 plays an active role in the survival of OSNs as an anti-apoptotic factor and confers immature OSNs enough time to fully differentiate into mature ones. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 70: 424-435, 2010 [source] Overbank deposition along the concave side of the Red River meanders, Manitoba, and its geomorphic significanceEARTH SURFACE PROCESSES AND LANDFORMS, Issue 13 2005Gregory R. Brooks Abstract Slow earth sliding is pervasive along the concave side of Red River meanders that impinge on Lake Agassiz glaciolacustrine deposits. These failures form elongated, low-angled (c. 6 to 10°) landslide zones along the valleysides. Silty overbank deposits that accumulated during the 1999 spring freshet extend continuously along the landslide zones over hundreds of metres and aggraded the lower slopes over a distance 50 to 80 m from the channel margin. The aggradation is not obviously related to meander curvature or location within a meander. Along seven slope profiles surveyed in 1999 near Letellier, Manitoba, the deposits locally are up to 21 cm thick and generally thin with increasing distance from, and height above, the river. Local deposit thickness relates to distance from the channel, duration of inundation of the landslide surface, mesotopography, and variations in vegetation cover. Immediately adjacent to the river, accumulated overbank deposits are up to 4 m thick. The 1999 overbank deposits also were present along the moderately sloped (c. 23 to 27°) concave banks eroding into the floodplain, but the deposits are thinner (locally up to c. 7 cm thick) and cover a narrower area (10 to 30 m wide) than the deposits within the landslide zones. Concave overbank deposition is part of a sediment reworking process that consists of overbank aggradation on the landslide zones, subsequent gradual downslope displacement from earth sliding, and eventually reworking by the river at the toe of the landslide. The presence of the deposits dampens the outward migration of the meanders and contributes to a low rate of contemporary lateral channel migration. Concave overbank sedimentation occurs along most Red River meanders between at least Emerson and St. Adolphe, Manitoba. © Her Majesty the Queen in right of Canada. [source] Design and application of oligonucleotide probes for fluorescent in situ identification of the filamentous bacterial morphotype Nostocoida limicola in activated sludgeENVIRONMENTAL MICROBIOLOGY, Issue 9 2001Jian Rong Liu 16S rRNA targeted probes, designed using sequence data from pure cultures of the three morphotypes of the filamentous bulking bacteria Nostocoida limicola I, II and III and their successful application to the in situ identification of these bacteria in activated sludge biomass samples are described here. Two probes were required to detect all the sequenced N. limicola II isolates. Results from fluorescent in situ hybridization suggest that the morphotypes N. limicola I and II contain at least two phylogenetically unrelated bacteria. The N. limicola II filaments that did not respond to the probes designed in this study fluoresced instead with the probes previously designed for the ,-Proteobacteria. The data also suggest that both N. limicola I and III can exist in activated sludge as single, paired or clumped cells and thus in a form not recognizable microscopically as this morphotype. Some N. limicola II filaments which responded to the probes designed here were much thinner than the filaments conventionally ,identified' as this morphotype and better fitted the descriptions often used in the literature for N. limicola I. [source] Changes in productivity and contaminants in bald eagles nesting along the lower Columbia River, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2005Jeremy A. Buck Abstract Previous studies documented poor productivity of bald eagles (Haliaeetus leucocephalus) in the lower Columbia River (LCR), USA, and elevated p,p,-dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), dioxins, and furans in eagle eggs. From 1994 to 1995, we collected partially incubated eggs at 19 of 43 occupied territories along the LCR and compared productivity and egg contaminants to values obtained in the mid-1980s. We found higher productivity at new nesting sites along the river, yet productivity at 23 older breeding territories remained low and was not different (p = 0.713) between studies. Eggshell thickness at older territories had not improved (p = 0.404), and eggshells averaged 11% thinner than shells measured before dichlorodiphenyltrichloroethane use. Decreases in DDE (p = 0.022) and total PCBs (p = 0.0004) in eggs from older breeding areas occurred between study periods. Productivity was not correlated to contaminants, but DDE, PCBs, and dioxin-like chemicals exceeded estimated no-effect values. Some dioxin-like contaminants in eggs were correlated to nest location, with highest concentrations occurring toward the river's mouth where productivity was lowest. Although total productivity increased due to the success of new nesting pairs in the region, egg contaminants remain high enough to impair reproduction at older territories and, over time, may alter productivity of new pairs nesting near the river's mouth. [source] Burrowing owls and agricultural pesticides: Evaluation of residues and risks for three populations in California, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2000Jennifer A. Gervais Abstract We examined selenium, organophosphorus, and organochlorine pesticide residues in egg, footwash, and feather samples from burrowing owls in three populations in central and southern California. Eggs from all sites contained detectable levels of p,p,-dichlorodiphenyldichloroethylene, with the San Joaquin Valley site containing up to 33 ,g/g (geometric mean x¯ = 7.52). Only low levels of polychlorinated biphenyls were detected, however (geometric mean x¯ = 1.98, n = 2). Selenuim concentrations were low in all samples (geometric mean x¯ = 0.426, n = 20). Eggshells collected in 1996 were 22% thinner than eggs collected prior to 1937. In addition, feather samples contained low levels of dichlorodiphenyldichloroethylene, and footwash samples indicated exposure to the pesticide chlorpyrifos. Pesticide-use records indicated that one population might also be at risk from applications of aldicarb near nests during the breeding season. [source] Muscle thickness and neuron density in the caecum of horses with chronic recurrent caecal impactionEQUINE VETERINARY JOURNAL, Issue S32 2000G. F. SCHUSSER Summary In this study, the hypothesis that caecal smooth muscle layers would be thinner and the linear neuron density of myenteric plexus greater was tested in normal horses compared to those with chronic recurrent caecal impaction. Four normal horses and 18 horses with chronic recurrent caecal impaction were subjected to euthanasia and 7 tissue samples were collected from each horse at different regions of the caecum (apex, dorsal body, cranial base, dorsal base, caudal base, caudal body, ventral body). Twelve horses with chronic recurrent caecal impaction were treated surgically. Only one tissue sample of the cranial part of the caecal base close to the caecocolic orifice was taken during surgery. The thickness of the circular muscle layer of all caecal regions measured in killed horses with chronic recurrent caecal impaction was significantly increased compared to the equivalent caecal region of normal horses. On the other hand, the longitudinal muscle layer was significantly thicker only in the cranial and caudal caecal base and in the dorsal region of the caecal body. The linear neuron densities of all caecal base areas and 2 caecal body regions, the caudal body region and of the apex, of killed horses with chronic recurrent caecal impaction were significantly lower compared with those in clinically normal horses. The circular muscle layer of all caecal regions was thickened (hypertrophied) probably as a consequence of chronic uncoordinated hypercontractility due to neuron deficit in the myenteric plexus of the caecal base. [source] ADAPTIVE PLASTICITY OF THE PENIS IN A SIMULTANEOUS HERMAPHRODITEEVOLUTION, Issue 8 2009J. Matthew Hoch Acorn barnacles are important model organisms for the study of sex allocation. They are sessile, nonselfing hermaphrodites that copulate with penises that have been suggested to be phenotypically plastic. On wave-exposed shores, Semibalanus balanoides develop penises with relatively greater diameter whereas in wave-protected sites they are thinner. A reciprocal transplant experiment between wave-exposed and protected sites tested whether these exposure-specific morphologies have adaptive value. Mating success was compared over a range of distances to compare the ability of barnacles to reach mates. Barnacles that grew in the wave-protected site and mated in the wave-protected site fertilized more broods at increasing distances than those transplanted to the wave-exposed site. For barnacles that developed in the wave-exposed site, there was no difference in the ability to fertilize neighbors between sites of differing exposure. This study demonstrates the adaptive value of plasticity in penis morphology. The results suggest a trade-off between development of a penis adapted to wave exposure and the ability to fertilize distant mates. Barnacles in different physical environments are limited by different factors, which may limit numbers of potential mates, constrain optimal sex allocation strategies and alter reproductive behavior. [source] Fabrication of Sub-10,nm Metallic Lines of Low Line-Width Roughness by Hydrogen Reduction of Patterned Metal,Organic Materials,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2010Mihaela Nedelcu Abstract The fabrication of very narrow metal lines by the lift-off technique, especially below sub-10,nm, is challenging due to thinner resist requirements in order to achieve the lithographic resolution. At such small length scales, when the grain size becomes comparable with the line-width, the built-in stress in the metal film can cause a break to occur at a grain boundary. Moreover, the line-width roughness (LWR) from the patterned resist can result in deposited metal lines with a very high LWR, leading to an adverse change in device characteristics. Here a new approach that is not based on the lift-off technique but rather on low temperature hydrogen reduction of electron-beam patterned metal naphthenates is demonstrated. This not only enables the fabrication of sub-10,nm metal lines of good integrity, but also of low LWR, below the limit of 3.2,nm discussed in the International Technology Roadmap for Semiconductors. Using this method, sub-10,nm nickel wires are obtained by reducing patterned nickel naphthenate lines in a hydrogen-rich atmosphere at 500,°C for 1,h. The LWR (i.e., 3 ,LWR) of these nickel nanolines was found to be 2.9,nm. The technique is general and is likely to be suitable for fabrication of nanostructures of most commonly used metals (and their alloys), such as iron, cobalt, nickel, copper, tungsten, molybdenum, and so on, from their respective metal,organic compounds. [source] Body size, locomotor speed and antipredator behaviour in a tropical snake (Tropidonophis mairii, Colubridae): the influence of incubation environments and genetic factorsFUNCTIONAL ECOLOGY, Issue 5 2001J. K. Webb Summary 1,The physical conditions experienced by reptile embryos inside natural nests can influence the size, shape and behaviour of the resultant hatchlings. Although most reptiles are tropical, the effects of incubation temperatures on offspring phenotypes have received little attention in tropical species. 2,The consequences of differences in thermal variance during incubation on offspring were studied in a tropical natricine snake (the Keelback Tropidonophismairii), which lays eggs in soil cracks of varying depths. Some 253 eggs from 19 clutches were incubated under two thermal regimes with identical mean temperatures (25·6 °C), but temperatures in the ,variable' treatment fluctuated more (21·8,29·6 °C) than those in the ,constant' temperature treatment (25·2,26·5 °C). These thermal regimes were similar to those of shallow (20 cm deep) and deep (40 cm deep) soil cracks, respectively, and represent thermal conditions inside natural nests and potential nest sites. 3,Incubation temperatures affected body size, shape and antipredator behaviour of hatchling snakes. Snakes from constant temperature incubation were longer and thinner than snakes from high variance incubation. Clutch effects influenced all offspring traits, with significant interactions between clutch of origin and incubation treatment for body size, but not swimming speed or behaviour. 4,There was a significant interaction between incubation treatment and offspring sex on neonate swimming speed. Incubation under cycling thermal regimes significantly increased swimming speeds of females, but had little effect on males. Such sex differences in phenotypic responses of hatchling snakes support a major assumption of the Charnov,Bull hypothesis for the evolution of temperature-dependent sex determination. [source] New perspectives on Holocene landscape development in the southern English chalklands: The upper Allen valley, Cranborne Chase, DorsetGEOARCHAEOLOGY: AN INTERNATIONAL JOURNAL, Issue 2 2005C. French A combination of on- and off-site paleoenvironmental and archaeological investigations of the upper Allen valley of Dorset, conducted from 1998,2002, has begun to indicate a different model of prehistoric landscape development to those previously put forward for this part of the southern English chalk downlands. Woodland growth in the earlier Holocene appears to have been slower and patchier than the presumed model of full climax deciduous woodland rapidly attained in a warming environment. With open areas still strongly present in the Mesolithic, the area witnessed its first exploitation, thus slowing and altering soil development. Consequently, many areas perhaps never developed thick, well-structured, brown forest earths, but more probably thin brown earths. By the later Neolithic period, these soils had become thin rendzinas, largely as a consequence of human exploitation and the predominance of pastoral land use. The early presence of thinner and less well-developed soils over large areas of downland removes the necessity for envisaging extensive soil erosion and the accumulation of thick colluvial and alluvial deposits in the dry valleys and valley floor as often postulated. If there were major changes in the vegetation and soil complexes in this area of chalk downland, these had already occurred by the Neolithic rather than the Bronze Age as often suggested, and the area has remained relatively stable ever since. This has major implications for models of prehistoric land use in the southern chalkland region, such as a much greater degree of stability in prehistoric and historic times, variability within sub-regions, and differences between different parts of the chalk downlands than had previously been envisaged. © 2005 Wiley Periodicals, Inc. [source] Waveform modelling of teleseismic S, Sp, SsPmP, and shear-coupled PL waves for crust- and upper-mantle velocity structure beneath AfricaGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2007Abhijit Gangopadhyay SUMMARY We describe a waveform modelling technique and demonstrate its application to determine the crust- and upper-mantle velocity structure beneath Africa. Our technique uses a parallelized reflectivity method to compute synthetic seismograms and fits the observed waveforms by a global optimization technique based on a Very Fast Simulated Annealing (VFSA). We match the S, Sp, SsPmP and shear-coupled PL phases in seismograms of deep (200,800 km), moderate-to-large magnitude (5.5,7.0) earthquakes recorded teleseismically at permanent broad-band seismic stations in Africa. Using our technique we produce P - and S -wave velocity models of crust and upper mantle beneath Africa. Additionally, our use of the shear-coupled PL phase, wherever observed, improves the constraints for lower crust- and upper-mantle velocity structure beneath the corresponding seismic stations. Our technique retains the advantages of receiver function methods, uses a different part of the seismogram, is sensitive to both P - and S -wave velocities directly, and obtains helpful constraints in model parameters in the vicinity of the Moho. The resulting range of crustal thicknesses beneath Africa (21,46 km) indicates that the crust is thicker in south Africa, thinner in east Africa and intermediate in north and west Africa. Crustal P - (4.7,8 km s,1) and S -wave velocities (2.5,4.7 km s,1) obtained in this study show that in some parts of the models, these are slower in east Africa and faster in north, west and south Africa. Anomalous crustal low-velocity zones are also observed in the models for seismic stations in the cratonic regions of north, west and south Africa. Overall, the results of our study are consistent with earlier models and regional tectonics of Africa. [source] Place and value of the recurrent laryngeal nerve (RLN) palpatory method in preventing RLN palsy during thyroid surgeryHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 4 2009DSci, Áron Altorjay MD Abstract Background. In recent years, certain publications have appeared confirming that intraoperative palpation of the recurrent laryngeal nerve (RLN) is a very reliable method. Method. The characteristics of the surgical anatomy of 1023 RLN have been summarized on the basis of intraoperative palpability, running down, branching variations, thickness, and laryngeal entry site. Results. Palpation was helpful in 81.4% (833/1023), proved false positive in 8.2% (84/1023), and in 10.4% (106/1023) it was of no help in the exact localization. Definitive RLN palsy was experienced in 0.78% of all cases (8/1023), while transient paresis was encountered in 1.2% (12/1023). Only a moderately strong stochastic correlation could be found between RLN palsies and those nerves which were nonpalpable and atypical, which showed the joint occurrence of being both thinner than normal and branching already before the plane of the inferior thyroid artery (Cramer's associate coefficient, C = 0.383). Conclusion. Palpation alone cannot substitute visualization and proper surgical dissection of the nerve. © 2008 Wiley Periodicals, Inc. Head Neck, 2009 [source] Effect of the plate thermal resistance on the heat transfer performance of a corrugated thin plate heat exchangerHEAT TRANSFER - ASIAN RESEARCH (FORMERLY HEAT TRANSFER-JAPANESE RESEARCH), Issue 3 2006Hiroshi Iwai Abstract Two-dimensional conjugate conduction/convection numerical simulations were carried out for flow and thermal fields in a unit model of a counter-flow-type corrugated thin plate heat exchanger core. The effects of the thermal resistance of the solid plate, namely the variation of the plate thickness and the difference of the plate material, on the heat exchanger performance were examined in the Reynolds number range of 100 Single-Component Molecular Conductor [Pt(tmdt)2] (tmdt,=,trimethylenetetrathiafulvalenedithiolate) , An Advanced Molecular Metal Exhibiting High MetallicityADVANCED MATERIALS, Issue 35 2009Biao Zhou A newly prepared single-component molecular metal, [Pt(tmdt)2], exhibited very high conductivity and metallic behavior down to 4 K in the compacted polycrystalline state. A ,conducting paint' of [Pt(tmdt)2] obtained by kneading the microcrystals with lacquer and thinner showed metallic conductivity at around room temperature. [source] Numerical studies of shear banding in interface shear tests using a new strain calculation method,INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 12 2007Jianfeng Wang Abstract Strain localization is closely associated with the stress,strain behaviour of an interphase system subject to quasi-static direct interface shear, especially after peak stress state is reached. This behaviour is important because it is closely related to deformations experienced by geotechnical composite structures. This paper presents a study using two-dimensional discrete element method (DEM) simulations on the strain localization of an idealized interphase system composed of densely packed spherical particles in contact with rough manufactured surfaces. The manufactured surface is made up of regular or irregular triangular asperities with varying slopes. A new simple method of strain calculation is used in this study to generate strain field inside a simulated direct interface shear box. This method accounts for particle rotation and captures strain localization features at high resolution. Results show that strain localization begins with the onset of non-linear stress,strain behaviour. A distinct but discontinuous shear band emerges above the rough surface just before the peak stress state, which becomes more expansive and coherent with post-peak strain softening. It is found that the shear bands developed by surfaces with smaller roughness are much thinner than those developed by surfaces with greater roughness. The maximum thickness of the intense shear zone is observed to be about 8,10 median particle diameters. The shear band orientations, which are mainly dominated by the rough boundary surface, are parallel with the zero extension direction, which are horizontally oriented. Published in 2007 by John Wiley & Sons, Ltd. [source] Thickness and continuity of the adherent colonic mucus barrier in active and quiescent ulcerative colitis and Crohn's diseaseINTERNATIONAL JOURNAL OF CLINICAL PRACTICE, Issue 5 2008V. Strugala Summary Background:, The colon is covered by a mucus barrier that protects the underlying mucosa and alterations in this mucus barrier have been implicated in the aetiology of inflammatory bowel disease (IBD). This study investigated the thickness and continuity of the mucus barrier in ulcerative colitis (UC) and Crohn's disease (CD) in comparison to normal controls. Methods:, Rectal biopsies were taken from 59 patients and cryostat sections stained with periodic acid-Schiff's/Alcian blue to visualise the mucus layer. Mucus thickness and continuity and goblet cell density were measured using light microscopy. Results:, An essentially continuous adherent mucus layer was observed in normal human rectum and there was no change in the mucus barrier in quiescent UC. In active UC there was a trend for the mucus layer to become progressively thinner and significantly more discontinuous as disease severity increased. In severe active UC the mucus layer thickness and goblet cell density were significantly reduced compared with normal controls while the percentage discontinuity significantly increased. Conclusion:, It is not until severe UC that there is a global change in mucosal protection as a consequence of large regions lacking mucus, a decrease in secretory potential caused by a loss of goblet cells and a thinner, less effective mucus layer even when it is present. [source] Location-related differences in structure and function of the stratum corneum with special emphasis on those of the facial skinINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 6 2008H. Tagami Synopsis Between the two different kinds of the skin covering the body, the glabrous skin is found only on the palmo-plantar surface because of its rather simple function to protect the underlying living tissue with its remarkably thick stratum corneum (SC) from strong external force and friction. Thus, its barrier function is extremely poor. In contrast, the hair-bearing skin covers almost all over the body surface regardless of the presence of long hair or vellus hair. In regard to its SC, many dermatologists and skin scientists think that it is too thin to show any site-specific differences, because the SC is just present as an efficient barrier membrane to protect our body from desiccation as well as against the invasion by external injurious agents. However, there are remarkable regional differences not only in the living skin tissue but also even in such thin SC reflecting the function of each anatomical location. These differences in the SC have been mostly disclosed with the advent of non-invasive biophysical instruments, particularly the one that enables us to measure transepidermal water loss (TEWL), the parameter of the SC barrier function, and the one that evaluates the hydration state of the skin surface, the parameter of the water-holding capacity of the SC that brings about softness and smoothness to the skin surface. These in vivo instrumental measurements of the SC have disclosed the presence of remarkable differences in the functional properties of the SC particularly between the face and other portions of the body. The SC of the facial skin is thinner, being composed of smaller layers of corneocytes than that of the trunk and limbs. It shows unique functional characteristics to provide hydrated skin surface but relatively poor barrier function, which is similar to that observed in retinoid-treated skin or to that of fresh scar or keloidal scars. Moreover, there even exist unexpected, site-dependent differences in the SC of the facial skin such as the forehead, eyelid, cheek, nose and perioral regions, although each location occupies only a small area. Between these locations, the cheek shows the lowest TEWL in contrast to the perioral region that reveals the highest one. Moreover, these features are not static but change with age particularly between children and adults and maybe also between genders. Among various facial locations, the eyelid skin is distinct from others because its SC is associated with poor skin surface lipids and a thin SC cell layer composed of large corneocytes that brings about high surface hydration state but poor barrier function, whereas the vermillion borders of the lips that are covered by an exposed part of the oral mucosa exhibit remarkably poor barrier function and low hydration state. Future studies aiming at the establishment of the functional mapping in each facial region and in other body regions will shed light on more delicate site-dependent differences, which will provide us important information in planning the strategy to start so called tailor-made skin care for each location of the body. Résumé Entre les deux types différents de peau couvrant le crops, on trouve la peau glabre uniquement sur la surface palmo-plantaire du fait de sa fonction plutôt simple de protection du tissu vivant sous-jacent par un stratum corneum (SC) trés épais vis-à-vis des forces extérieures et de la friction. De ce fait, sa fonction barrière est extrêmement pauvre. Au contraire, la peau velue courve la presque totalité de la surface du crops, que ce soit par la présence de longs cheveux ou de duvet. En ce qui concerne son SC, la plupart des dermatologues et des scientifiques de la peau pensent qu'il est trop mince pour montrer une différence spécifique au site, attendu que le SC est simplement présent en tant que membrane barriére efficace pour protéger notre corps de la dessiccation ainsi que pour lutter contre l'invasion d'agents nuisibles externes. Cependant, il existe des différences importantes entre les sites, non seulement dans la peau vivante, mais également dans ce SC aussi mince, qui révèlent la fonctin de chaque site anatomique. Ces différences dans le SC ont surtout été révélées avec l'apparition d'instruments biophysiques non invasifs, en particulier celui qui nous permet de mesurer la perte transépidermale en eau (TEWL), le paramétre de la fonction barrière du SC et celui qui évalue l'état d'hydratation de la surface de peau, le paramètre de la capacité en rétention de l'eau du SC qui est liéà la souplesse et à la douceur à la surface de peau. Ces mesures instrumentales in vivo du SC ont révélé la présence de différences remarquables entre les propriétés fonctionnelles du SC particulièrement entre le visage et d'autres parties du corps. Le SC de la peau de la face est plus mince, car li est composé de couches plus petites de corneocytes que celui du tronc et des membres. Il montre des caractéristiques fonctionnelles uniques pour permettre l'hydratation de la surface de peau, mais une fonction barrière relativement faible, semblable à celle observée dans la peau traitée avec un rétinoïde ou à celle d'une cicatrice récente ou de cicatrices kéloidales. De plus, il existe des différences sites-dépendantes inattendues dans le SC de la peau de la face comme le front, la paupière, la joue, le nez et les régions périorales, et ce, bien que chaque emplacement occupe seulement un petit secteur. Entre ces divers emplacements, la joue montre le TEWL le plus bas par comparaison avec la région périorale qui montre le plus élevé. De plus, ces caractéristiques ne sont pas fixes, mais changent avec l'âge en particulier entre enfants et adultes et peut-être aussi entre sexes. Entre les diverses régions de la face, la peau de la paupière se distingue parce que son SC est associéà une peau pauvre en lipides de surface constituée par une mince couche de cellule composée de grand cornéocytes qui provoquent un haut état d'hydratation superficiel, mais une faible fonction barrière. A l'inverse les bordures vermillion des lévres recouvertes par une partie exposée de muqueuse orale, possèdent une fonction barrière très faible et un état d'hydratation bas. Les études futures visant àétablir la configuration fonctionnelle de chaque région de la face et d'autres régions du corps mettrons en lumière des différences sites-dépendantes plus subtiles, qui nous fourniront des informations importantes pour planifier la stratégie pour commencer le soin de la peau sur mesure si attendu pour chaque partie du corps. [source] Annular atrophic lichen planusINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 5 2007Rosa María Ponce-Olivera MD A 30-year-old woman presented with a 1-year history of a pruritic eruption on the extremities, characterized by several annular plaques. The patient had been treated unsuccessfully with medium-potency topical steroids. The lesions had an erythematous papular border with an atrophic center (width, 1,4 cm) (Fig. 1). No oral, genital, or nail lesions were observed. Figure 1. Annular lesion with an infiltrated border and atrophic center A skin biopsy from one of the plaques was performed. Histopathologic examination of the raised border showed hyperkeratosis of the stratum corneum, focal thickening of the granular layer, basal liquefaction degeneration of the epidermis, and a band-like subepidermal infiltration with numerous Civatte bodies. In the center of the lesion, the epidermis became thinner (Fig. 2). Elastic fibers were reduced or absent in the papillary dermis. Figure 2. (a) Biopsy of the border of a plaque with the typical changes of lichen planus (hematoxylin and eosin, ×10), with flattened epidermis in the center of the plaque; (b) medium power of the border of the plaque with details of the changes of lichen planus (hematoxylin and eosin, ×40) The patient was treated with high-potency topical steroids for 2 months with clinical improvement. [source] A longitudinal study of the development of dieting among 7,17-year-old Swedish girlsINTERNATIONAL JOURNAL OF EATING DISORDERS, Issue 1 2002Klara Halvarsson Abstract Objective To examine the extent to which the prevalence of self-reported dieting and the wish to be thinner changed in 7,15-year-old girls over a 3-year period, and to explore potential differences between cohorts recruited in 1995 and 1999. In addition, changes in eating attitudes (Children's Eating Attitudes Test [ChEAT]) were compared between 1995 and 1999. Method A three-wave longitudinal study including girls (n = 1,076,1,279) in five age groups (7, 9, 11, 13, 15, the Main Cohort) and an age-matched cross-sectional sample consisting of 1,759 girls (the Societal Cohort). Results A marked increase of the wish to be thinner was evident in the 10,14-year-old age range and significant increases in dieting attempts occurred mainly among 9,13-year-old girls. ChEAT scores were significantly higher among 11-year-olds in 1999 than in 1995. However, more 7-year-olds scored above the ChEAT cutoff (,15) in 1995 compared with 1999. Discussion There was an increasing trend in the wish to be thinner and in dieting attempts among 9,14-year-olds. Attitudes and behaviors associated with disturbed eating had increased between 1995 and 1999 only among the 11-year- olds. © 2002 John Wiley& Sons, Inc. Int J Eat Disord 31: 32,42, 2002. [source] Age changes in bone microstructure: do they occur uniformly?INTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 6 2005G. A. Macho Abstract Age estimations based on conventional multifactorial methods were compared with trends observed in the internal morphology of bones obtained from high-resolution µCT. Specifically, average trabecular thickness and number of trabeculae/mm transect were determined in the non-load-bearing capitate (hand) and the load-bearing navicular (foot). The µCT findings reveal age-related trends but,surprisingly,these correspond only loosely with the ages assigned by conventional ageing methods, and are also not in accordance with what would be predicted from biomechanical considerations: trabeculae tend to be thinner in the (habitually) load-bearing navicular than in the (habitually) non-load-bearing capitate. While the statistically significant correlation between trabecular thickness and number of trabeculae would suggest a compensatory mechanism between these two aspects of microanatomy, they are not correlated with the assigned ages and, importantly, may differ between sexes. Only in females is there an unequivocal trend towards trabecular thickness increase with age. These findings, although unexpected, can be reconciled with recent histological evidence and assumed average activity levels in historical populations. Conversely, changes in trabecular number are less clear-cut and may be due to the lack of very old individuals in the sample. Nevertheless, the trends observed for trabecular thickness, as well as for trabecular number, seem to imply that the higher incidence of osteoporosis in women could be explained from a structural point of view alone. Copyright © 2005 John Wiley & Sons, Ltd. [source] Variation of crustal thickness in the Philippine Sea deduced from three-dimensional gravity modelingISLAND ARC, Issue 3 2007Takemi Ishihara Abstract Crustal thickness of the northern to central Philippine Sea was gravimetrically determined on the simple assumption of four layers: seawater, sediments, crust and lithospheric mantle, with densities of 1030, 2300, 2800 and 3300 kg/m3, respectively. As for the correction of the regional gravity variation, a 15 km difference of the lithospheric thickness with a density difference of 50 kg/m3 against the asthenosphere below between both sides of the Kyushu-Palau Ridge was taken into consideration. Mantle Bouguer anomalies were calculated on the assumption of constant crustal thickness of 6 km, and then the crustal thickness was obtained by three-dimensional gravity inversion method. The results show occurrence of thin crust areas with a thickness of approximately 5 km in the southern part and at the western margin of the Shikoku Basin and also of thick crust areas in the northwestern and northeastern parts of the Parece Vela Basin. We suggest that these are because of the variation of magma supply at the time of sea floor spreading in the Shikoku and Parece Vela Basins, which is possibly related to the variation of spreading rate and enhanced magmatism near the past arc volcanic fronts. The results further show the occurrence of crust thinner than 5 km in the northeastern part of the West Philippine Basin, of crust thicker than 15 km in the Amami Plateau, the Daito and Oki-Daito Ridges, and also in the northern part of Kyushu-Palau Ridge, whereas the southern part of the Kyushu-Palau Ridge the crust is thicker than 10 km. It was also inferred that small basins in the Daito Ridge province have the thinnest oceanic crust of less than 5 km in the Kita-Daito Basin. [source] The structural design of the bat wing web and its possible role in gas exchangeJOURNAL OF ANATOMY, Issue 6 2007Andrew N. Makanya Abstract The structure of the skin in the epauletted fruit bat (Epomophorus wahlbergi) wing and body trunk was studied with a view to understanding possible adaptations for gas metabolism and thermoregulation. In addition, gas exchange measurements were performed using a respirometer designed for the purpose. The body skin had an epidermis, a dermis with hair follicles and sweat glands and a fat-laden hypodermis. In contrast, the wing web skin was made up of a thin bilayered epidermis separated by a connective tissue core with collagen and elastic fibres and was devoid of hair follicles and sweat glands. The wings spanned 18,24 cm each, with about 753 cm2 of surface exposed to air. The body skin epidermis was thick (61 ± 3 µm, SEM), the stratum corneum alone taking a third of it (21 ± 3 µm). In contrast, the wing web skin epidermis was thinner at 9.8 ± 0.7 µm, with a stratum corneum measuring 4.1 ± 0.3 µm (41%). The wing capillaries in the wing web skin ran in the middle of the connective tissue core, with a resultant surface-capillary diffusion distance of 26.8 ± 3.2 µm. The rate of oxygen consumption (V,O2) of the wings alone and of the whole animal measured under light anaesthesia at ambient temperatures of 24 ºC and 33 ºC, averaged 6% and 10% of the total, respectively. Rate of carbon dioxide production had similar values. The membrane diffusing capacity for the wing web was estimated to be 0.019 ml O2 min,1 mmHg,1. We conclude that in Epomophorus wahlbergi, the wing web has structural modifications that permit a substantial contribution to the total gas exchange. [source] Genotoxicity study in lymphocytes of offset printing workersJOURNAL OF APPLIED TOXICOLOGY, Issue 1 2006Hüseyin Aksoy Abstract The potential cytogenetic damage in offset printing workers was evaluated using sister chromatid exchanges (SCEs), chromosome aberrations (CAs) and micronuclei (MN) as biomarkers in peripheral lymphocytes of 26 volunteers (14 workers, 12 controls). The CA, SCE and MN frequency of offset printing workers was significantly higher than in their controls. The replication index (RI) was not affected while the mitotic index (MI) was affected most in the workers. It can be concluded from this study that chronic occupational exposure to printing dyes and thinner may lead to a slightly increased risk of genetic damage among offset printing workers. Copyright © 2005 John Wiley & Sons, Ltd. [source] Histological biocompatibility of new, non-absorbable glaucoma deep sclerectomy implantJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2007Jakub J. Ka Abstract We performed this study to compare the intrascleral biocompatibility of three materials: non-absorbable hydrogel contact lens polymer, non-absorbable silicone rubber, and absorbable cross-linked sodium hyaluronate. Intrascleral implantation of three different materials was performed in 13 healthy, pigmented rabbits. Implants of methacrylic hydrogel, silicone rubber, and cross-linked sodium hyaluronate were implanted in 10, 8, and 8 eyes, respectively. The animals were euthanized at 7, 30, 180, and 360 days post implantation. The eyes were enucleated and immediately fixed in 10% buffered formalin. Semithin sections were cut and stained with hematoxylin-eosin. Light microscope analysis of the specimens was performed. The least severe inflammatory reaction was observed with cross-linked sodium hyaluronate implants. The number of inflammatory cells in proximity to methacrylic hydrogel and silicone implants at all periods of follow up was similar. The thickest fibrous capsule was observed with silicone implants (average, 28.38 ± 11.17 ,m). This area was thinner with methacrylic hydrogel implants (average, 14.90 ± 5.57 ,m) and was thinnest around sodium hyaluronate implants (average, 7.21 ± 2.33 ,m). For each type of implant, the wall on the conjunctival side of the fibrous capsule was significantly thicker than the wall on the choiroidal side. The space between the implant, scleral flap, and bed was filled soon after surgery with connective tissue rich in vessels. In our study, cross-linked sodium hyaluronate had the highest intrascleral biocompatibility. Although the inflammatory responses of the sclera to methacrylic hydrogel and silicone rubber were similar in nature, a thicker fibrous capsule was generated around silicone implants. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006 [source] Behavior of dense and porous hydroxyapatite implants and tissue response in rat femoral defectsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 1 2002J.C.T. Andrade Abstract Porous and dense hydroxyapatite cylinders (PHA and DHA) were implanted into cavities produced in rat femora and the sites of implantation were examined at different times over a period of 24 weeks by microradiologic and histological techniques. Microradiographs showed the presence of a layer of trabecular bone around the implants, which became more radiopaque and thinner along the experimental time. The microradiologic methodology used was suitable for the evaluation of the interface between hydroxyapatite and newly formed bone in nondecalcified materials. Microscopic observations showed that young bone grew over the surface of both types of implants after 1 and 2 weeks of surgery and that bone also grew inside PHA implants. Progressive bone absorption was observed in both types of implants after the fourth week. A layer of fibrous tissue was formed in the interface between new bone and DHA. Mature bone with haversian systems surrounded DHA implants and filled the pores of PHA implants throughout the experimental period. The pores of PHA implants were smaller than those commonly reported, which should have been a disadvantage, although it was observed that the extra cellular fluid induced disintegration of the ceramic granules, allowing the gradual growth of bone tissue into the spaces among them, without the interposition of fibrous tissue. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 30,36, 2002 [source]
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