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排序方式: 共有327条查询结果,搜索用时 31 毫秒
271.
Mohammed Rebbah Yahya Slimani Abdelkader Benyettou Lionel Brunie 《Cluster computing》2016,19(1):13-27
Computational grids have the potential for solving large-scale scientific problems using heterogeneous and geographically distributed resources. At this scale, computer resources and network failures are no more exceptions, but belong to the normal system behavior. Therefore, one of the most valuable characteristics of grid tools, apart from the performance they can achieve, is fault tolerance, which is a significant and complex issue in grid computing systems. In this paper, we propose a fault tolerant model for grid computing systems namely DCFT. This model is based on dynamic colored graphs without replication of computer resources. The proposed faut tolerance model consists of two stages. In the first stage, each node is described by a state vector. We color each attribute of the state vector as three colors (green, blue and red) based on its level of performance. In the second stage, we classify the nodes of a grid into three categories: the identical computer resources in term of performance, the more efficient ones and the less efficient ones. We used the colors of the nodes to develop a new strategy for fault tolerance based on the level of performance. A simulation of the proposed model using SimGrid simulator and Graphstream is conducted. Experimental results show that the proposed model performs very well in a large grid environment. 相似文献
272.
Faugeroux V Génisson Y Salma Y Constant P Baltas M 《Bioorganic & medicinal chemistry》2007,15(17):5866-5876
Three (S)-prolinol-derived conformationally restricted analogues of the antitubercular agent ethambutol were prepared and tested against Mycobacterium tuberculosis. 相似文献
273.
Fulwah Yahya Alqahtani Fadilah Sfouq Aleanizy Amany Z. Mahmoud Nida Nayyar Farshori Rihaf Alfaraj Ebtesam Saad Al-sheddi Ibrahim A. Alsarra 《Saudi Journal of Biological Sciences》2019,26(5):1089-1092
Lepidium sativum (garden cress) seed oil was examined for its antimicrobial, antioxidant, and anti-inflammatory activities. The oil was obtained by hydrodistillation, where gas chromatography coupled with mass spectrometry that utilized to study its chemical composition. Microdilution method was used to test the antimicrobial effect of oil against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Klebsiella pneumoniae, and Candida albicans. The antioxidant activity was assessed by radical scavenging activity assay using 2,2-diphenyl-1-picrylhydrazyl radical. The major constituents found in the oil were 7,10-hexadecadienoic acid, 11-octadecenoic acid, 7,10,13-hexadecatrienoic acid, and behenic acid. The minimum inhibitory concentration (MIC) against all pathogens was 47.5 mg/ml, except for Salmonella enterica, which showed MIC of 90 mg/ml. The oil demonstrated antioxidant activity in a dose dependent pattern, with a half maximal inhibitory concentration (IC50) value of 40 mg/ml, and exerted anti-inflammatory activity, wherein 21% protection was shown at a concentration of 300 μg/ml. Thus, L. sativum seed oil shows antimicrobial, antioxidant, and anti-inflammatory properties. 相似文献
274.
The objective of the study was to examine changes in microbial parameters have been used to monitor changes in soil quality under different land uses in north of Iran. The microbial parameters included microbial respiration (MR), substrate induced respiration (SIR), carbon availability index (CAI), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), ratio of MBC/MBN, metabolic quotient (qCO2) and microbial ratio were determined under different land use/cover, i.e. virgin natural forest (VNF), degraded natural forest (DNF), alder plantation (AP), sequoia plantation (SP), improved fallow (IF) and home garden (HG) areas in northern Iran. Five composed samples per land use/cover were taken from the top 10 cm of the soil. MR and SIR (0.45 and 1.66 mg CO2-C g?1 day?1, respectively) were found to be significantly higher under AP land uses than in the other areas. CAI did not differ for the land uses; MBC (591 and 590 mg kg?1, respectively) had higher significantly under SP and VNF land uses than in the other areas. MBN (64.25 and 62.33, respectively mg kg?1) was significantly higher in AP and VNF land uses, ratio of MBC/MBN (17.02) was higher in SP land use than other areas, HG had significantly higher qCO2 (0.0012 μg CO2-C mg?1 MBC day?1) and finally microbial ratio was significantly higher under IF (599.16) in comparison with HG > AP ≈ DNF > VNF > SP areas. Overall, our results indicate that AP land use (Alnus subcordata C. A. Mey.) increase of soil quality and alder plantation is suitable for rehabilitation of degraded natural forests. 相似文献
275.
276.
Arshag D. Mooradian Jacob L. Pinnas Chien-Cheng Lung M. Danial Yahya Keith Meredith 《Neurochemical research》1994,19(2):123-128
To determine the effect of diabetes mellitus on cerebral microvessel protein composition, post translational modification of proteins with glucose and malondialdehyde (MDA) was determined and the abundant protein species found in cerebral microvessels isolated from control and streptozotocin-induced diabetic rats were studied. Two dimensional gel electrophoresis and computer assisted densitometry revealed that only one out of 25 quantitated proteins was significantly altered in diabetic rats after 5 weeks of uncontrolled hyperglycemia. The level of glycosylation of cerebral microvessel protein mixture was significantly increased in diabetic rats compared to control rats (168.8±25 vs 109.5±4.8 nmol/mg) (p<0.05). Western blot analysis of cerebral microvessel proteins from diabetic rats using a specific antibody against MDA-modified proteins revealed three protein spots with molecular weights of approximately 60,000 Kd. These were shown not to be contaminants from cerebral tissue or plasma proteins modified with MDA. It is concluded that short duration of streptozotocin-induced diabetes mellitus in rats is associated with some qualitative changes in protein composition of cerebral microvessels. These changes may contribute to the diabetes-related alterations in the blood-brain barrier. 相似文献
277.
Comparison of assimilable organic carbon and UV-oxidizable carbon for evaluation of ultrapure-water systems. 总被引:1,自引:1,他引:0 下载免费PDF全文
Bacterial growth potential was measured in an ultrapure-water pilot plant by modified assimilable organic carbon (AOC) and UV-oxidizable carbon tests. An ion-exchange unit increased UV-oxidizable carbon, yet did not significantly (P greater than or equal to 0.05) alter AOC values. UV radiation decreased UV-oxidizable carbon and increased AOC. 相似文献
278.
Yahya Rahimpour Mina Doorandishan Anahita Boveiri Dehsheikh Mohammad Mahmoodi Sourestani Javad Mottaghipisheh 《化学与生物多样性》2023,20(5):e202201071
The present study was aimed at comprehensive overviewing a phytochemically and biologically important species namely Torilis japonica (Apiaceae family). Treatment of dysentery, fever, haemorrhoids, spasm, uterine tumors, lymphadenitis, rheumatism, impotence, infertility, women's diseases, and chronic diarrhea are reported as the main folk medicinal applications of the T. japonica fruits. So far, the plant is phytochemically characterized for its diverse terpene derivatives, predominantly sesquiterpenes. The plant's fruit is a rich source of torlin, a guaiane-type sesquiterpene, possessing various potent bioactivities. To date, anticancer, anti-inflammatory, antimicrobial, antioxidant, skin photoaging activities of the plant extracts and its constituents have been evaluated. Further investigation of the plant, specifically bioassay-guided isolation and identification of its major bioactive constituents can lead to discover potential phytopharmaceutical candidates. 相似文献
279.
Soliman Mona H. Alnusairi Ghalia S. H. Khan Amir Abdullah Alnusaire Taghreed S. Fakhr Marwa A. Abdulmajeed Awatif M. Aldesuquy Heshmat S. Yahya Muhammad Najeeb Ullah 《Journal of Plant Growth Regulation》2023,42(3):1522-1543
Journal of Plant Growth Regulation - In a controlled environment experiment, we studied how physiological changes in leaves during the vegetative phase regulate final grain yield of wheat crops in... 相似文献
280.
Yahya Mrestani Reinhard Neubert J rg Schiewe Albert H rtl 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,690(1-2):321-326
Cephalosporins have structures and antibiotic activity similar to those of penicillins which represent a class of compounds with closely related structures. Most of the cephalosporins contain aromatic groups and show distinctive UV spectra. Separating the different types of cephalosporins is a challenging task for HPLC, but the resolving power of capillary zone electrophoresis (CZE) makes this separation fast and simple. The present study reports the application of CZE for cephalosporin analysis and the separation of cephalosporins from plasma. Both field strength and temperature were shown to influence the plate number. The influence of injection time on the peak height was studied. Furthermore, the influence of pH value on the separation of cephalosporins by CZE was investigated. The low sample amount required and the relatively short analysis time are the main advantages of this method. 相似文献