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排序方式: 共有509条查询结果,搜索用时 15 毫秒
31.
S Daoui YY Cui V Lagente X Emonds-Alt C Advenier 《Canadian Metallurgical Quarterly》1997,10(5-6):261-270
Aerosolized substance P (0.1 M, for 30 min) induced airway hyperresponsiveness in guinea-pigs 24 h after they were pre-treated with salbutamol (8.7 mM by aerosol for 10 min) and phosphoramidon (0.1 mM by aerosol for 10 min). This was displayed by an exaggerated response to the bronchoconstrictor effect of acetylcholine. A microvascular leakage hypersensitivity also occurred and was demonstrated by a potentiation of the plasma protein extravasation from bronchial vessels induced by histamine. The aim of this study was to investigate the effects of the non-peptide and potent tachykinin NK3 receptor antagonist, SR 142801 (osanetant), in comparison with those of the tachykinin NK1 and NK2 receptor antagonists, SR 140333 (nolpitantium) and SR 48968 (saredutant) respectively, on substance P. When given once at 1 mg/kg i.p. 45 min before exposure to substance P, SR 142801 prevented both hyperresponsiveness to acetylcholine and the potentiation of histamine-induced increase in microvascular permeability. SR 142801 did not exhibit any tachykinin NK1 or NK2 antagonistic activity in experiments on guinea-pig isolated airways, in vitro or in vivo. The results suggest that tachykinin NK3 receptors might be involved in these substance P-induced effects on airways. 相似文献
32.
Chin-Chia Wu Wen-Chiung Lee Yau-Ren Shiau 《The International Journal of Advanced Manufacturing Technology》2007,33(11-12):1237-1243
This paper investigates a single-machine problem in which processing times of jobs are start time dependent and the aim is to minimize the total weighted completion time. Recent research has shown the complexity of this problem to be NP-hard; however, no optimal or heuristic algorithms have been proposed. In this paper, we explore the exact solution and propose several heuristic algorithms derived based on the impacts of model parameters. The effects of normal processing times and deterioration rates are also studied. 相似文献
33.
Flooding vulnerability assessment is an important issue in Taiwan since Taiwan lies within the most active tropical cyclone
formation zone of the Western Pacific. Huge economic damages and losses of human lives are occurred almost every year. This
study aims to evaluate flooding vulnerability of a given area subject to large-scale land developments. A scoring-based approach
associated with a physiographic drainage-inundation model is developed to quantitatively evaluate vulnerability for flooding.
The flooding vulnerability index defined as the product of an exposure score and a hazard score. The exposure score assesses
relative losses exposed to flooding, which is determined by land-uses classification. The hazard score measures flooding severity,
which is simultaneously determined by inundation depth and duration that are obtained from the inundation model for a design
storm. The Yenshui River basin located in southwestern Taiwan is used an example to illustrate the proposed method. The results
show that the projected urbanization plan within the Yenshui River basin would increase flooding vulnerability from 0.371
to 0.472. However, this value is reduced to 0.388 when the mitigation measure has been implemented. The obtained spatial distribution
of flooding vulnerability for a design storm provides decision-makers useful information to identify hotspots of the study
area and evaluate effects of flood-mitigation measure on flooding risk-reduction. 相似文献
34.
The Ilizarov method has broad applications for the generation of bone and soft tissue via an external fixator composed of small pins, tensional wires, rings, hinges and distractors. The success of the technique depends on adherence to Ilizarov's principles of tension-stress phenomenon: preservation of the tissues' blood supply, frequent distraction in small increments, and full function of the extremity. 相似文献
35.
说到七喜(HEDY),我们都对它的IT产品以及代理的硬件产品非常熟悉,但是说到七喜的手机,可能市场知名度就没那么高,确实,七喜在2006年8月份刚刚拿到手机牌照,但是在相对较短的时间内推出了多款手机新品,完全可以看出七喜对手机产品的重视,而且在发布的手机产品中,七喜涉及的种类非常广泛,既有流行滑盖设计,也有时尚直板风格,可见七喜的雄心,而H777是七喜旗下首歌主打音乐牌的机型,由于七喜本身在MP3播放器领域有着多年经验,而且作为实力雄厚的代理商,七喜在控制价格方面很有一套,如此一来,自然很让人期待H777的表现。[编者按] 相似文献
36.
Fitting Drought Duration and Severity with Two-Dimensional Copulas 总被引:22,自引:0,他引:22
J. T. Shiau 《Water Resources Management》2006,20(5):795-815
This study aims to model the joint drought duration and severity distribution using two-dimensional copulas. The method of inference function for margins (IFM method) is employed to construct copulas. Two separate maximum likelihood estimations of univariate marginal distributions are performed first, then followed by a maximization of the bivariate likelihood as a function of the dependence parameters. The drought duration and severity are assumed to be exponential and gamma distributions, respectively. Several copulas are tested to determine the best data fitted copula. Droughts, defined using the Standardized Precipitation Index (SPI), of Wushantou (Taiwan) are employed as an example to illustrate the proposed methodology. The copula fitting results for drought duration and severity are quite satisfactory. The bivariate drought analyses, including the joint probabilities and bivariate return periods, based on the derived copula-based joint distribution are also investigated to demonstrate the advantages of bivariate modeling of droughts. 相似文献
37.
WP Lin DD Ji CY Shiau TC Yang YW Yang TL Tsou ST Tang CH Chen YT Liu 《Canadian Metallurgical Quarterly》2003,142(3):158-165
Compounds N-(6,7-difluoroquinolonyl)-ampicillin (AU-1) and N-(6-fluoroquinolonyl)-ampicillin (FQ-1), synthesized by coupling of the carboxyl group of 6,7-difluoroquinolone (FP-3) and 6-fluoroquinolone (FP4), respectively, with the alpha-amino-group of ampicillin side chain, exhibit antipseudomonal activity similar to and lower acute toxicity than that of norfloxacin, whereas neither ampicillin nor the fluoroquinolone moieties, compound FP-3 or FP4, alone have such activity. Also, AU-1 and FQ-1 are active against tested clinical isolates of Pseudomonas aeruginosa that are highly resistant to norfloxacin, gentamicin, or both. The therapeutic efficacies of FQ-1 and norfloxacin were assessed and compared in neutropenic mice infected with a 90% lethal dose of P aeruginosa. Mice intraperitoneally administered FQ-1 (10 mg/kg) 4, 8, 24, and 48 hours after infection had survival rates as high as 80%, comparable to those of mice treated with norfloxacin at the same dosage and dosing schedule. The study of protoplast formation revealed that FQ-1 did not inhibit cell-wall biosynthesis but did induce cell filamentation of Bacillus subtilis at a level close to its minimal inhibition concentration. Both AU-1 and FQ-1 were able to intercalate into the double-stranded DNA. However, that FQ-1 lost such activity after it was treated with penicillinase suggests that the lactam-ring structure in ampicillin moiety of FQ-1 was hydrolyzed by penicillinase and that the hydrolyzed structure of FQ-1 does not own DNA-intercalation activity. 相似文献
38.
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40.
The type and distribution of keratins (K) in malignant tumors of eyelids were examined immunohistochemically to understand the pathomechanism of intercellular interactions. All of the tumor cells in the basal cell carcinoma were positive for K14, which is specific for basal cells, whereas all of them were negative for K10, which is specific for suprabasal layers in stratified squamous epithelia. These findings suggest that basal cell carcinoma may consist of uniform, basal cell-like tumor cells. On the other hand, the squamous cell carcinoma and sebaceous carcinoma, which were positive for either K14 or K10 to varying extent, may consist of various tumor cells with different types and degrees of differentiation. In these tumors, K14 was frequently detected throughout the border cells of the tumor mass. Apoptotic bodies were detected at the region where this continuous distribution of K14 was interrupted. These findings may help to clarify the pathomechanism of the interactions between the tumor cells and stromal cells. 相似文献