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951.
本文用原子吸收光谱对恒沸酸中微量表面活性剂FC-95进行了定量分析,并叙述了实验方法、样品处理方法等。 相似文献
952.
JL Wiley DR Compton PM Gordon C Siegel M Singer A Dutta AH Lichtman RL Balster RK Razdan BR Martin 《Canadian Metallurgical Quarterly》1996,35(12):1793-1804
delta 8-Tetrahydrocannabinol (delta 8-THC) is a naturally occurring cannabinoid with a characteristic pharmacological profile of in vivo effects. Previous studies have shown that modification of the structure of delta 8-THC by inclusion of a nitrogen-containing functional group alters this profile and may alkylate the cannabinoid receptor, similar to the manner in which beta-funaltrexamine (beta-FNA) alkylates the micro-opioid receptor. Two novel analogs of delta 8-THC were synthesized: a nitrogen mustard analog with a dimethylheptyl side chain (NM-delta 8-THC) and a cyano analog with a dimethylpentyl side chain (CY-delta 8-THC). Both analogs showed high affinity for brain cannabinoid receptors and when administered acutely, produced characteristic delta 9-THC-like effects in mice, including locomotor suppression, hypothermia, antinociception and catalepsy. CY-delta 8-THC shared discriminative stimulus effects with CP 55,940; for NM-delta 8-THC, these effects also occurred, but were delayed. Although both compounds attenuated the effects of delta 9-THC in the mouse behavioral tests, evaluation of potential antagonist effects of these compounds was complicated by the fact that two injections of delta 9-THC produced similar results, suggesting that acute tolerance or desensitization might account for the observations. NM-delta 8-THC, but not CY-delta 8-THC, attenuated the discriminative stimulus effects of CP 55,940 in rats several days following injection. Hence, addition of a nitrogen-containing functional group to a traditional cannabinoid structure does not eliminate agonist effects and may produce delayed attenuation of cannabinoid-induced pharmacological effects. 相似文献
953.
通常认为拍摄脉冲全息肖像必须使用带有Q开关运转模式的脉冲激光器,否则是不可能拍摄成功的。本文介绍了我们使用无Q开关的脉冲激光器研制出高质量脉冲质量肖像的工作,以及在此情况下应注意的若干问题。 相似文献
954.
Altered growth and branching patterns in synpolydactyly caused by mutations in HOXD13 总被引:2,自引:0,他引:2
Hox genes regulate patterning during limb development. It is believed that they function in the determination of the timing and extent of local growth rates. Here, it is demonstrated that synpolydactyly, an inherited human abnormality of the hands and feet, is caused by expansions of a polyalanine stretch in the amino-terminal region of HOXD13. The homozygous phenotype includes the transformation of metacarpal and metatarsal bones to short carpal- and tarsal-like bones. The mutations identify the polyalanine stretch outside of the DNA binding domain of HOXD13 as a region necessary for proper protein function. 相似文献
955.
Rehabilitation after soft-tissue autograft reconstructions is controversial because there is indirect evidence that some grafts fail by creeping over time. The vulnerability of soft-tissue grafts to creep over healing time and the effects of the load environment during healing on this vulnerability have never been studied specifically. We hypothesized that immobilization would decrease the magnitude of the vulnerability of ligament grafts to creep. Thirty-nine skeletally mature New Zealand White rabbits underwent a standardized medial collateral ligament autograft procedure to the right hindlimb, and 19 of the rabbits also had the limb rigidly pinned into flexion. Subgroups were killed at 3 or 8 weeks, and all isolated tibia/medial collateral ligament/femur complexes were tested for creep at 4.1 MPa under a standardized protocol. Eight normal medial collateral ligament controls were tested similarly. Results showed that all grafts were quantitatively more susceptible to cyclic and static creep than were normal medial collateral ligament controls (p < 0.05). By 3 weeks of healing, immobilization significantly increased the magnitude of the vulnerability of the grafts to cyclic, static, and total creep (all: p < 0.05). Furthermore, the grafts had more unrecovered creep strain than did the controls following a 20-minute recovery period. Contrary to our hypothesis, immobilization resulted in increased vulnerability of these ligament autografts to creep even with this relatively nonprovocative test of short duration and low stress. We postulate that following immobilization, this increase in the magnitude of susceptibility of the grafts to creep will result in functionally significant elongation of the graft if it is exposed to higher loads and over longer periods of time in vivo. 相似文献
956.
H Rabinowich TE Reichert Y Kashii BR Gastman MC Bell TL Whiteside 《Canadian Metallurgical Quarterly》1998,101(11):2579-2588
We have recently reported that tumor-associated lymphocytes obtained from ascitic fluids of women with ovarian carcinoma (OvCA) demonstrate a marked decrease in expression of cytoplasmic CD3-zeta and surface CD3-epsilon chains, which is associated with altered function of T cell receptor (TcR). We now demonstrate that OvCAs in situ and in culture express functional Fas ligand (FasL), capable of triggering an intrinsic cell death program in Fas-expressing T cells. The possibility of a relationship between cell death and altered expression of TcR was examined. The data indicate that alterations in expression of CD3-zeta and CD3-epsilon chains in T cells coincubated with OvCA are related to tumor-induced apoptosis, as the addition of pan-caspase inhibitors, DEVD-cho or YVAD-cho, prevents both the in vitro induction of T cell death by OvCA cells and the changes in the level of expression of CD3-zeta and CD3-epsilon chains. In the presence of Fas-Fc fusion protein, but not Fc-control protein, the loss in expression of CD3-zeta and CD3-epsilon chains induced in T cells by FasL+ OvCA cells was prevented. These results suggest that the loss in expression of CD3-zeta and CD3-epsilon chains in T lymphocytes interacting with OvCA cells is associated with apoptosis mediated by FasL-expressing tumor cells. 相似文献
957.
A distributed expert control system (DECSHZ) has been built for a hydrometallurgical zinc process, whose basic steps are leaching, purification and electrolysis. It consists of a central computer management system and three local expert control systems, one for each of the basic steps. This paper deals with the design and application of DECSHZ, especially its distributed architecture and main functions; expert control strategies based on rule models and a combination of rule models and steady-state mathematical models; system implementation; and the results of actual runs. DECSHZ has been found to provide not only a very pure product, but also significant economic benefits. 相似文献
958.
Previous reports have suggested that NO is an important mediator of the antihypertensive effects of renin-angiotensin system (RAS) inhibition. We examined the effects of the NO synthase inhibitor L-NNA on the hypotensive effects of captopril, the Ang II antagonist EXP 3174, or the renin inhibitor terlakiren. In sodium-depleted guinea pigs (GPs), L-NNA (3 mg/kg) increased MAP by 15-21% for at least 5 hours. L-NNA partially blocked the hypotensive effects of captopril (1 mg/kg, iv), but not those of EXP 3174 (1 mg/kg, iv) or terlakiren (3 mg/kg). In sodium-depleted rats, 10 mg/kg L-NNA (iv) increased MAP by 16-22%, and partially or fully blocked the hypotensive effect of EXP 3174 (1 mg/kg, iv) or captopril (3 mg/kg, iv), respectively. Thus, in contrast to the rat, NO in GPs appears to participate only in the hypotensive action of ACE inhibition and does not appear to be strongly involved in the hypotensive action of AII antagonism or renin inhibition. The involvement of NO in the hypotensive effects of RAS antagonists other than ACE inhibitors may be species-dependent. 相似文献
959.
BR Ferrell 《Canadian Metallurgical Quarterly》1998,29(9):41-43
A review and survey of nurses' responsibility for delivering care at the end of life. 相似文献
960.
This paper studies the prevalence of risk factors considered responsible for osteoporosis in women of 4 occupational groups: farmers, blue collar workers, white collar workers/civil servants and housewives. We analyzed nutritional factors associated with osteoporosis in the scientific literature. The total sample comprises of 2185 individuals of which 658 women were taken into the analyses. The data set was based on a health survey conducted in 10 selected rural communities of Styria in Austria between 1995 and 1996. Sociodemographic data, lifestyles, internal and external resources as well as indicators off ill-health were surveyed through standardized personal interviews. The results show that the women of the 4 occupational groups were differently strained regarding nutritional risk factors. Our results suggest that efficient intervention programs to prevent osteoporosis need to specifically focus on the various life contexts of women. 相似文献