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排序方式: 共有1705条查询结果,搜索用时 15 毫秒
1.
TD Foley 《Canadian Metallurgical Quarterly》1997,235(2):374-376
The effects of 1 microM concentrations of arachidonic acid hydroperoxide (HPETES) products of 5-, 12- and 15-lipoxygenase on Na+, K(+)-ATPase activity were investigated in synaptosomal membrane preparations from rat cerebral cortex. 5-HPETE inhibited Na+, K(+)-ATPase activity by up to 67 %. In contrast, 12-HPETE and 15-HPETE did not inhibit Na+, K(+)-ATPase activity. In addition, neither 5-HETE or LTA4 inhibited Na+, K(+)-ATPase activity. Dose-response studies indicated that 5-HPETE was a potent (IC25 = 10(-8) M) inhibitor of Na+, K(+)-ATPase activity. These findings indicate that 5-HPETE inhibits Na+, K(+)-ATPase activity by a mechanism that is dependent on the hydroperoxide position and independent of further metabolism by 5-lipoxygenase. It is proposed that 5-HPETE production by 5-lipoxygenase and subsequent inhibition of neuronal Na+, K(+)-ATPase activity may be a mechansim for modulating synaptic transmission. 相似文献
2.
Mark Sherman Jonathan Rosenberg Ann Marks Jaap Akkerhuis 《Computer Standards & Interfaces》1991,11(3):177-182
Many advanced document systems provide a formatting mechanism called ‘style sheets’ Style sheets provide a great deal of flexibility in describing a document's format, and allow easy maintenance of different house styles for a collection of documents. In this paper, we describe the basics of general style sheet systems, argue that successful document interchange must include the exchange of style sheet information, and evaluate ODA's style mechanism against this requirement. 相似文献
3.
Rosenberg Florian Curbera Francisco Duftler Matthew J. Khalaf Rania 《Internet Computing, IEEE》2008,12(5):24-31
The use of RESTful Web services has gained momentum in the development of distributed applications based on traditional Web standards such as HTTP. In particular, these services can integrate easily into various applications, such as mashups. Composing RESTful services into Web-scale workflows requires a lightweight composition language that's capable of describing both the control and data flow that constitute a workflow. The authors address these issues with Bite, a lightweight and extensible composition language that enables the creation of Web-scale workflows and uses RESTful services as its main composable entities. 相似文献
4.
Identification of a gene that causes primary open angle glaucoma 总被引:3,自引:0,他引:3
EM Stone JH Fingert WL Alward TD Nguyen JR Polansky SL Sunden D Nishimura AF Clark A Nystuen BE Nichols DA Mackey R Ritch JW Kalenak ER Craven VC Sheffield 《Canadian Metallurgical Quarterly》1997,275(5300):668-670
Glaucoma is a major cause of blindness and is characterized by progressive degeneration of the optic nerve and is usually associated with elevated intraocular pressure. Analyses of sequence tagged site (STS) content and haplotype sharing between families affected with chromosome 1q-linked open angle glaucoma (GLC1A) were used to prioritize candidate genes for mutation screening. A gene encoding a trabecular meshwork protein (TIGR) mapped to the narrowest disease interval by STS content and radiation hybrid mapping. Thirteen glaucoma patients were found to have one of three mutations in this gene (3.9 percent of the population studied). One of these mutations was also found in a control individual (0.2 percent). Identification of these mutations will aid in early diagnosis, which is essential for optimal application of existing therapies. 相似文献
5.
6.
CP Gibbs TD Peabody AJ Mundt AG Montag MA Simon 《Canadian Metallurgical Quarterly》1997,79(6):888-897
We reviewed the cases of sixty-two patients who had had a subcutaneous sarcoma to determine the effect of tumor and treatment-related variables on the rates of survival and local recurrence. Fifty-nine (95 per cent) of the patients had had an operation at another hospital before being referred to us. Twenty-nine (47 per cent) of the sixty-two tumors were high-grade, forty-two (68 per cent) were small (five centimeters or less), and thirty (48 per cent) were malignant fibrous histiocytomas. We followed a treatment strategy that consisted of repeat excision with the goal of obtaining wide margins. Excluding thirteen patients who had had a palpable local recurrence at the time of presentation, twenty (49 per cent) of forty-one patients who had had a marginal excision at another hospital had microscopic residual tumor on repeat excision. At a median of fifty-six months after the repeat excision, fifty (81 per cent) of the sixty-two patients had been continuously disease-free, one had no evidence of disease, eight had died of the disease, and three had died of other causes. The five-year rate of disease-free survival was 85 per cent (fifty-three of sixty-two patients). There were three local recurrences, all in patients who had had a marginal resection. No recurrences were noted in patients who had had a wide local excision of the tumor or of the previous operative field. Multivariate analysis revealed that a large tumor (greater than five centimeters), a marginal excision, and adjuvant radiation therapy were associated with a worse prognosis. Excellent rates of survival for patients who have a subcutaneous sarcoma, including those who have a large or high-grade tumor and those who have residual tumor following a previous operation, can be obtained with carefully planned operative treatment alone. We recommend operative excision or repeat excision with wide margins because of the high prevalence of residual tumor. Size is the most important tumor-related factor, and the operative margin is the most important treatment-related factor. The additional value of adjuvant radiation therapy remains unproved. 相似文献
7.
Hartung J. Jacquin A. Pawlyk J. Rosenberg J. Okada H. Crouch P.E. 《Selected Areas in Communications, IEEE Journal on》1998,16(1):42-55
This paper describes a prototype video coding platform meant for the conception and testing of multimedia products such as next-generation videophones. The platform is largely based on ITU-T Recommendation H.263, with a number of additional object-oriented quality enhancement features which make it especially well suited for very low bit-rate coding of “head-and-shoulders” video material typical of real-time multimedia applications, video teleconferencing, and video telephony. These features consist of: (1) segmentation into objects of interest, (2) segmentation-based prefiltering, (3) model-assisted rate control, (4) adaptive vector quantization, and finally (5) segmentation-based postfiltering. In the spirit of Recommendation H.263, these enhancements are modular and can be selectively turned on or off, thereby enabling a wide variety of coding modes 相似文献
8.
TD Blumenthal 《Canadian Metallurgical Quarterly》1994,31(2):201-203
In some laboratories, eyeblink electromyogram is rectified and smoothed before the analog signal is digitized. The relationship among the integrator time constant, the duration of the response, and the attenuation of the data was investigated by passing a number of signals at durations of 5, 10, 20, 50, and 100 ms into a contour-following integrator (Coulbourn model S76-01), which first rectifies and then smooths (integrates) the signal. Integrator time constants of 10, 42, 70, 144, and 300 ms were used. The output of the integrator was sampled (1,000 Hz) and stored on a Macintosh SE computer. The integrator attenuated the signal, and the amount of attenuation increased as the duration of the signal decreased and as the time constant of the integrator increased. For brief inputs, the integrator does not charge fully, so only the early portion of the charge limb is present, and this early portion is the steepest part of the charge limb. Therefore, the longer the time constant, the less likely that small or brief responses will be detected. 相似文献
9.
The homogeneity of comminuted composites of 20 lb samples of apples, cabbage, and green beans containing field-incurred residues of p, p'-methoxychlor was studied to determine whether a 5 min comminution in a 40 qt vertical cutter mixer produces a homogeneous composite and whether the size of test portions used accurately represents the composite. Duplicate test portions of 100, 50, 25, 10, 5, and 2 g taken from each of 6 separate sections of the mixer were analyzed by standard pesticide residue methodology for p, p'-methoxychlor. Results of this study confirmed that comminution of fresh produce in a 40 qt vertical cutter mixer, according to instructions described in the U.S. Food and Drug Administration's Pesticide Analytical Manual, Volume I, Section 203B, produces a homogeneous composite. No significant differences were found in the data for the 3 crops taken from the 6 sections of the mixer. Test portion weights of 100, 50, and 25 g produced equivalent results for all 3 crops. Statistically significant differences were observed for cabbage at 2, 5, and 10 g and for green beans at 2 g. 相似文献
10.
Pregnant Sprague-Dawley rats were administered primidone (PRM) by oral gavage on gestation days 8-17 in doses of 0.40, and 80 mg/kg. Although these doses of PRM did not produce significant differences in litter size, birth weight, mortality, date of attainment of developmental landmarks or measures of preweaning reflex and motor development, there were a number of significant differences that developed as the animals approached and entered adulthood. When tested as adults, the 80 mg/kg male rats showed a deficit in the performance of an eight-arm radial maze task. These same animals showed a significant reduction in open field activity when tested as adults. In addition, both male and female PRM-treated animals showed reduced body weights at different periods corresponding to onset of sexual maturation during development. These findings are consistent with the larger body of literature reporting on the neurobehavioral teratology of phenobarbital, including its ability to produce lesions in the hippocampus and endocrine dysfunction resulting in reproductive deficits. These results suggest that PRM produces its adverse effects as a result of its metabolism to phenobarbital, which in turn affects the limbic system. 相似文献