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991.
992.
SB Han HM Kim YH Kim CW Lee ES Jang KH Son SU Kim YK Kim 《Canadian Metallurgical Quarterly》1998,20(1-3):1-13
One of the characteristics of obesity-associated diabetes is an elevated fasting plasma insulin concentration with a weak insulin secretory response to subsequent glucose stimulation. Evidence suggests that hyperglycemia and hyperlipidemia may contribute to the initiation and progression of this disordered islet glucose sensing. It has been proposed that reducing hyperglycemia and hyperlipidemia per se may improve islet glucose sensing. Here we studied glucose-dependent insulin release in islets isolated from ob/ob mice treated with dopamine agonists (bromocriptine and SKF38393, BC/SKF) which significantly reduced circulating glucose and lipid levels of ob/ob mice. Islets from BC/SKF-treated mice showed a marked decrease of the elevated basal insulin release to levels similar to lean mice. Such treatment also induced a higher secretory response to glucose stimulation compared with that in ob/ob mice with sustained hyperglycemia and hyperlipidemia. Similarly, when islets from untreated ob/ob mice were cultured for 7 days in 11 mM glucose in the absence of free fatty acid, the basal insulin release was significantly decreased and high glucose stimulated insulin release increased compared with that from islets cultured in medium containing 30 mM glucose and 2 mM oleate. The BC/SKF-induced reduction of elevated basal insulin release was associated with decreased hexokinase activity and basal cyclic AMP content in islet tissue. Our results demonstrate that dopamine agonist treatment improves basal insulin release in ob/ob mice and this effect may be mediated, in part, by a reduction of hyperglycemia and hyperlipidemia. 相似文献
993.
研究在醋酸、蚁酸和柠檬酸的条件下利用染料的酸性隐色体的形式来染色的技术。同时研究了尿素的加入对提高染料上染的作用。除此之外,对靛蓝染料染色后的样品进行反复多次清洗,并与分散染料的染色样品相比较,以此测试牢度性能。 相似文献
994.
B. R. Kim J. W. Kang K. Y. Lee J. M. Son M. J. Ko 《Journal of Materials Science》2007,42(12):4591-4602
Though spin-on organosilicates are considered as the promising candidates of low dielectric constant materials, it is necessary
for a successful integration to improve mechanical strength such as modulus and fracture toughness. In this study, five sets
of MTMS–BTMSE copolymers were synthesized and characterized while the monomer content of BTMSE (bis(trimethoxysilyl)ethane)
was varied from 9.1 to 47.3 mol% vs. MTMS (methyltrimethoxysilane). In parallel with the measurement of dielectric constant,
four different tests were carried out to evaluate mechanical properties of the MTMS–BTMSE copolymers. Modulus was measured
by the nanoindentation technique and the modified edge lift-off test (MELT) was employed to extract adhesive fracture toughness
quantitatively. In addition, residual stress was calculated by sensing the change in radius of curvature of the substrate.
The chemical structure of the copolymers was also analyzed with FTIR and NMR. Network formation was enhanced as the amount
of BTMSE increased, which led to improvement of modulus and the increase in refractive index and dielectric constant. However,
an increasing rate of fracture toughness by the MELT was not proportional to the increase in the amount of BTMSE, which implied
that it was necessary to optimize the composition of the copolymers since adhesion strength was conjectured the most critical
factor for a successful integration. 相似文献
995.
The effects of ultraviolet (UV) intensity and wavelength on triclosan (TCS) photodegradation kinetic, efficiency, mechanisms and pathway were studied. The TCS photodegradation followed the pseudo-first order kinetic model at all UV intensities examined at the wavelengths of 254 and 365 nm and the photodegradation rate increased with increasing UV intensity. TCS photodegradation efficiencies of 90 to 98% and 79 to 90% were obtained at the wavelengths of 254 and 365 nm, respectively. TCS was degraded mainly by photon induced hydroxyl radicals while the direct photon reaction with TCS played a subordinate role. Chlorophenol, dichlorophenol and phenol were the intermediates detected in all experiments conducted. Dibenzodichloro-p-dioxin and dibenzo-p-dioxin were observed as the intermediates only at lower UV intensities investigated at the wavelength of 365 nm. Based on these intermediates, a complete TCS photolysis pathway was proposed for the first time. 相似文献
996.
In 2 children with an inlet ventricular septal defect and straddling chordae tendineae of the septal leaflet of the tricuspid valve to the posteromedial papillary muscle of the mitral valve and to an accessory papillary muscle in the left ventricle, the straddling chordae were excised with a wedge of posteromedial papillary muscle and with the top segment of the accessory papillary muscle, respectively. After patch closure of the ventricular septal defect, the papillary muscle segment with its group of chordae was anchored to the right ventricular septum with resulting competence of the tricuspid valve. In contrast to the traditional repair technique, the reported modification is applicable when the straddling chordae insert into a papillary muscle of the mitral valve. In addition, various disadvantages related to the construction of a complex baffle in the inappropriate ventricle are avoided. 相似文献
997.
Intracellular Ca2+ release mediates ursolic acid-induced apoptosis in human leukemic HL-60 cells 总被引:1,自引:0,他引:1
JH Baek YS Lee CM Kang JA Kim KS Kwon HC Son KW Kim 《Canadian Metallurgical Quarterly》1997,73(5):725-728
The Centre de Recherche sur les Méningites et les Schistosomes (CERMES) is a research institute depending on the Organisation de Coordination et de Coopération pour la lutte contre les Grandes Endémies--a West African Organization for Public Health--devoted to the studies on schistosomiasis and meningitis. The staff includes 32 persons with 11 scientists and one financial officer. The activities of the CERMES involving schistosomiasis concern three research units: (a) ecology of human and animal schistosomiasis transmission; the CERMES defined the different patterns of schistosomiasis transmission in Niger (involving African dry savana); in this field, we have shown, (i) the existence of important variability in conditions of transmission of S. haematobium and, (ii) natural hybridization between parasitic species of the ruminants (S. bovis and S. curassoni) and genetic interaction between human and animal parasites; (b) definition of morbidity indicators usable for rapid assessment methods, for appraisal of the severity of the disease and for the evaluation of the efficiency of control methods; we have established the correlation between ultrasonographic data and some cheap and simple field indicators; (c) immune response and protective immunity induced by recombinant glutathion S-transferase (Sm28, Sb28 and Sh28) in homologous and heterologous animal models including goats, sheep and non human primates (Erythrocebus patas). In Niger, we participate in all control programs against schistosomiasis to define control strategies, to supervise operations and to participate in their evaluation with external experts. International collaborations constitute a frame including four laboratories in Africa and six laboratories in developed countries (Europe and USA). 相似文献
998.
Sensitivity analysis for process parameters in GMA welding processes using a factorial design method 总被引:1,自引:0,他引:1
I. S. Kim K. J. Son Y. S. Yang P. K. D. V. Yaragada 《International Journal of Machine Tools and Manufacture》2003,43(8):206
Generally, the quality of a weld joint is strongly influenced by process parameters during the welding process. In order to achieve high quality welds, mathematical models that can predict the bead geometry and shape to accomplish the desired mechanical properties of the weldment should be developed. This paper focuses on the development of mathematical models for the selection of process parameters and the prediction of bead geometry (bead width, bead height and penetration) in robotic GMA (Gas Metal Arc) welding. Factorial design can be employed as a guide for optimization of process parameters. Three factors were incorporated into the factorial model: arc current, welding voltage and welding speed. A sensitivity analysis has been conducted and compared the relative impact of three process parameters on bead geometry in order to verify the measurement errors on the values of the uncertainty in estimated parameters. The results obtained show that developed mathematical models can be applied to estimate the effectiveness of process parameters for a given bead geometry, and a change of process parameters affects the bead width and bead height more strongly than penetration relatively. 相似文献
999.
In 10 of 14 patients with an active cytomegalovirus (CMV) infection, distinctive large cells (35-45 microns in diameter) were present in the peripheral blood. Morphologically these cells closely resembled the classic cytomegalic inclusion cells, generally regarded as a diagnostic hallmark of CMV infection. Moreover, these cells were shown to express CMV antigens belonging to all three stages of the viral replication cycle, indicating a productive CMV infection. In addition, immunologic staining with monoclonal antibodies directed against cell differentiation and marker proteins showed that these circulating cytomegalic cells were of endothelial origin. The presence of CMV-infected endothelial cells in the peripheral blood of patients with an active CMV infection indicates that such an infection might be accompanied by widespread occult vascular damage. 相似文献
1000.
DD Trach JD Clemens NT Ke HT Thuy ND Son DG Canh PV Hang MR Rao 《Canadian Metallurgical Quarterly》1997,349(9047):231-235
BACKGROUND: Several studies have shown that orally administered killed cholera vaccines are safe and protective in populations at risk of cholera in developing countries. However, these vaccines have not been adopted for use in developing countries because of their expense and limited efficacy in young children. We have tested an inexpensive, killed whole-cell cholera vaccine developed and produced in Vietnam. METHODS: The efficacy of the vaccine was assessed in a large-scale, open field trial in people at least 1 year old residing in 22,653 households in the central coastal city of Hue. Alternate households were assigned vaccine (67,395 people; two doses per person) or no vaccine (67,058 people). Surveillance for cholera was conducted in all Ministry of Health facilities serving this population. Analysis was by intention to treat. FINDINGS: During an outbreak of El Tor cholera 8-10 months after vaccination, 37 cases of cholera requiring inpatient care occurred among age-eligible people allocated to the vaccine group, and 92 cases among age-eligible people allocated to the no-vaccine group (protective impact 60% [95% CI 40-73]). Among the 51,975 people who received the complete two-dose vaccine regimen, the protective efficacy was 66% (46-79): in this subset, the protective efficacy was similar for children aged 1-5 years (68%) and for older people (66%). INTERPRETATION: These findings suggest that oral killed whole-cell vaccines can confer substantial protection against El Tor cholera in young children, who are at highest risk of cholera in endemic settings. An inexpensive, locally produced, and effective oral cholera vaccine may be within reach of the limited health-care budgets of poor countries with endemic cholera, if our findings can be replicated in a randomised double-blind trial. 相似文献