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21.
P Barrett G Davidson DG Hazlerigg MA Morris AW Ross PJ Morgan 《Canadian Metallurgical Quarterly》1998,139(1):163-171
22.
The Internet technology known as the World Wide Web is rapidly emerging as the most powerful medium of mass communication this century and it can be harnessed to dispense global, cost-effective, high-quality, multimedia patient education material. This paper reviews how the Internet has progressed from delivering simple static, text-based material to sophisticated interactive Web sites based on CGI Technology. Interactive Web sites can be used to deliver health assessment questionnaires and Web-based decision-support systems can give patients advice on the emergency management of acute medical problems. The advantages and drawbacks of this new technology, including information regulation and quality are discussed. The role of the Hospital Intranet as a patient education resource is described. The paper concludes by illustrating how patients can appreciate the 3-D structure of bones and organs using virtual reality in a VRML Web environment. 相似文献
23.
D Elias H Prigozin N Polak M Rapoport AW Lohse IR Cohen 《Canadian Metallurgical Quarterly》1994,43(8):992-998
Administered at a suitably low dose, the toxin streptozotocin (STZ) can trigger an autoimmune process leading to destruction of the beta-cells of the pancreatic islets. In this study, we examined specific immunological reactions in mice before and during the development of STZ-induced autoimmune diabetes. We now report that the development of spontaneous autoantibodies to insulin can serve as a marker of susceptibility to a low dose of STZ. Susceptible male mice of the C57BL/KsJ strain manifested such anti-insulin antibodies, and resistant female mice did not. Administration of a low dose of STZ (five daily doses each of 30 mg/kg) induced transient hyperglycemia approximately 20-30 days later, which temporarily remitted but was followed by intractable diabetes approximately 2.5 months later. The diabetogenic process triggered by the low dose of STZ was associated with an increase in the level of anti-insulin antibodies bearing the Dana and Micha (DM) idiotype, later followed by the appearance of anti-idiotypic antibodies that peaked before the onset of diabetes. Antibodies and T-cells reactive to hsp60 (heat shock protein) were triggered by the low-dose STZ administration and persisted throughout the period that preceded clinical diabetes. T-cells reactive to the p277 peptide of hsp60 were also observed. Finally, active immunization to hsp60 caused transient hyperglycemia by itself and also aggravated the hyperglycemia induced by low-dose STZ. Thus, autoantibodies to insulin can indicate susceptibility to a toxic trigger of diabetes, and a low dose of a toxin can activate the insulin and hsp60 autoimmunity that has been detected previously in the spontaneous autoimmune diabetes of NOD strain mice. 相似文献
24.
MI Aguilar DJ Clayton P Holt V Kronina RI Boysen AW Purcell MT Hearn 《Canadian Metallurgical Quarterly》1998,70(23):5010-5018
Procedures have been developed to identify the chromatographic binding domains of horse heart cytochrome c (Cyt c) and bovine growth hormone (bGH) during their interaction with reversed-phase sorbent materials. The procedure involves adsorption of the protein solute to the chromatographic sorbent, followed by proteolytic cleavage. Comparison of the proteolytic map obtained for Cyt c and bGH in free solution with the corresponding map obtained when these proteins are adsorbed to the chromatographic sorbent revealed significant differences in the digestion pattern. Following characterization of the peptides generated in both maps, the results indicated that specific regions on the surface of both Cyt c and bGH are inaccessible to tryptic cleavage when adsorbed to the hydrophobic surface of both a C-4 and a C-18 sorbent. Based on the assumption that the region of the protein surface that is in contact with the sorbent remains intact and bound to the sorbent during the digestion step, while the protein surface that is exposed to the solvent is accessible to proteolysis, the regions that were inaccessible to tryptic digestion were found to correspond to hydrophobic domains on the protein surface. These results also suggest that the three-dimensional structures of these proteins remain largely intact upon adsorption to the hydrophobic surface. 相似文献
25.
26.
The dynamics of avalanches of granular materials from initiation to runout. Part II. Experiments 总被引:1,自引:0,他引:1
Summary This paper describes a model to predict the flow of an initially stationary mass of cohesionsless granular material down a rough curved bed and checks it against laboratory experiments that were conducted with two different kinds of granular materials that are released from rest and travel in a chute consisting of a straight inclined section, a curved segment that is followed by a straight horizontal segment. This work is of interest in connection with the motion of landslides, rockfalls and ice and dense flow snow avalanches. Experiments were performed with two different granular materials, nearly spherical glass beads of 3 mm nominal diameter, Vestolen particles (a light plastic material) of lense type shape and 4 mm nominal diameter and 2,5 mm height. Piles of finite masses of these granular materials with various initial shapes and weight were released from rest in a 100 mm wide chute with the mentioned bent profile. The basal surface consisted of smooth PVC, but was in other experiments also coated with drawing paper and with sandpaper. The granular masses under motion were photographed and partly video filmed and thus the geometry of the avalanche was recorded as a function of position and time. For the two granular materials and for the three bed linings the angle of repose and the bed friction angle were determined. The experimental technique with which the laboratory avalanches were run are described in detail as is the reliability of the generated data. We present and use the depth-averaged field equations of balance of mass and linear momentum as presented by Savage and Hutter [28]. These are partial differential equations for the depth averaged streamwise velocity and the distribution of the avalanche depth and involve two phenomenological parameters, the internal angle of friction, ø, and a bed friction angle, , both as constitutive properties of Coulomb-type behaviour. We present the model but do not derive its equations. The numerical integration scheme for these equations is a Lagrangian finite difference scheme used earlier by Savage and Hutter [27],[28]. We present this scheme for completeness but do not discuss its peculiarities. Comparison of the theoretical results with experiments is commenced by discussing the implementation of the initial conditions. Observations indicate that with the onset of the motion a dilatation is involved that should be accomodated for in the definition of the initial conditions. Early studies of the temporal evolution of the trailing and leading edges of the granular avalanche indicate that their computed counterparts react sensitively to variations in the bed friction angle but not to those of the internal angle of friction. Furthermore, a weak velocity dependence of the bed friction angle, , is also scen to have a small, but negligible influence on these variables. We finally compare the experimental results with computational findings for many combinations of the masses of the granular materials and bed linings. It is found that the experimental results and the theoretical predictions agree satisfactorily. They thus validate the simple model equations that were proposed in Savage and Hutter [28]. 相似文献
27.
Since the mid-1980s, dramatic progress has been made in the evolution of hernia surgery, highlighted by the increasing use of prosthetic mesh. Among the mesh-based "tension-free" hernioplasties, the use of mesh plugs has garnered a large number of spirited enthusiasts, and plug herniorrhaphy has become the fastest growing hernia repair currently employed by the American surgeon. To demonstrate the simplicity and effectiveness of mesh plugs, a 9-year experience with almost 3300 patients is reported. Technical details are discussed and presentation of a literature search serves to further emphasize the utilitarian nature of this elegantly unsophisticated surgical operation. 相似文献
28.
DI Blyth MS Pedrick TJ Savage H Bright JE Beesley S Sanjar 《Canadian Metallurgical Quarterly》1998,19(1):38-54
29.
M Gleeson AW Cripps MJ Hensley JH Wlodarczyk RL Henry RL Clancy 《Canadian Metallurgical Quarterly》1996,26(6):697-702
BACKGROUND: The Pharmacia ImmunoCAP system (CAP) for assaying serum IgE specific antibodies was evaluated in a clinical setting against skin-prick test (SPT) performed using Dome/Hollister-Steir allergen extracts. The five common inhalant allergens D. pteronyssinus, D. farinae, mould mix, grass mix and cat epithelium were tested concurrently by both methods in 167 children aged 7.5-12 years. The specific SPT for D. pteronyssinus and D. farinae were also tested against the CAP house dust mite (HDM) mix. OBJECTIVE: The purpose of the study was to determine the sensitivity and specificity of the Pharmacia ImmunoCAP system for detecting serum IgE specific antibodies to inhalant allergens in a clinical setting, using SPT result as the "gold standard'. METHODS: The SPTs were performed using Dome/Hollister-Steir allergen extracts. The serum IgE specific antibodies were quantitated using the radioimmunoassay version of the Pharmacia ImmunoCAP system. A history of allergic disease was assessed using a validated questionnaire. RESULTS: SPT gave more positive reactions than CAP with the exception of cat epithelium. The concordance between SPT and CAP results was 91% over all the tests. The concordance with SPT was slightly higher for the specific CAP for D. pteronyssinus and D. farinae (93% and 95% respectively) than for the CAP HDM mix (86% and 90% respectively). There was a higher proportion of positive results for both SPT and CAP in the 115 children defined as having a history of allergic disease. Using SPT defined allergy as the gold standard, the sensitivity of the CAP system was 87% for the two specific house dust mites but was lower for cat epithelium (67%), mould mix (59%) and grass mix (46%). The sensitivity of the CAP system improved for D. pteronyssinus (96%) and the HDM mix (91%) when tested in subjects defined as having a history of allergy associated disease. The specificity of the CAP system showed less variation between allergens and ranged from 90-99%. CONCLUSION: The results of this study of children aged 7.5-12 years demonstrate that, for the inhalant allergens tested, the Pharmacia ImmunoCAP system performs well in the setting of known allergic disease. 相似文献
30.
F Fu Y Li S Qian L Lu F Chambers TE Starzl JJ Fung AW Thomson 《Canadian Metallurgical Quarterly》1996,62(5):659-665
We have shown previously that granulocyte-macrophage colony-stimulating factor-stimulated mouse bone marrow-derived MHC class II+ dendritic cell (DC) progenitors that are deficient in cell surface expression of the costimulatory molecules B7-1 (CD80) and B7-2 (CD86) can induce alloantigen-specific T-cell anergy in vitro. To test the in vivo relevance of these findings, 2 x 10(6) B10 (H2b) mouse bone marrow-derived DC progenitors (NLDC 145+, MHC class II+, B7-1dim, B7-2-/dim) that induced T-cell hyporesponsiveness in vitro were injected systemically into normal C3H (H2k) recipients. Seven days later, the mice received heterotopic heart transplants from B10 donors. No immunosuppressive treatment was given. Median graft survival time was prolonged significantly from 9.5 to 22 days. Median graft survival time was also increased, although to a lesser extent (16.5 days), in mice that received third-party (BALB/c; H2d) DC progenitors. Ex vivo analysis of host T-cell responses to donor and third-party alloantigens 7 days after the injection of DC progenitors (the time of heart transplant) revealed minimal anti-donor mixed leukocyte reaction and cytotoxic T lymphocyte reactivity. These responses were reduced substantially compared with those of spleen cells from animals pretreated with "mature" granulocyte-macrophage colony-stimulating factor + interleukin-4-stimulated DC (MHC class IIbright, B7-1+, B7-2bright), many of which rejected their heart grafts in an accelerated fashion. Among the injected donor MHC class II+ DC progenitors that migrated to recipient secondary lymphoid tissue were cells that appeared to have up-regulated cell surface B7-1 and B7-2 molecule expression. This observation may explain, at least in part, the temporary or unstable nature of the hyporesponsiveness induced by the DC progenitors in nonimmunosuppressed recipients. 相似文献