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71.
Hamdollah Panahpour Ali Akbar Nekooeian Gholam Abbas Dehghani 《Iranian Biomedical Journal》2014,18(4):232-238
Background: Angiotensin II (Ang II) has an important role on cerebral microcirculation; however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. Methods: Rats were exposed to 60-min middle cerebral artery (MCA) occlusion. Vehicle and non-hypotensive doses of candesartan (0.1 mg/kg) were administered one hour before ischemia. Neurological dysfunction scoring was evaluated following 24 h of reperfusion. Animals were then decapitated under deep anesthesia for the assessments of cerebral infarct size, edema formation, and BBB permeability. Results: The outcomes of 24 h reperfusion after 60-min MCA occlusion were severe neurological disability, massive BBB disruption (Evans blue extravasation = 12.5 ± 1.94 µg/g tissue), 4.02% edema, and cerebral infarction (317 ± 21 mm3). Candesartan at a dose of 0.1 mg/kg, without changing arterial blood pressure, improved neurological dysfunction scoring together with significant reductions in BBB disruption (54.9%), edema (59.2%), and cerebral infarction (54.9%). Conclusions: Inactivation of central AT1 receptors, if not accompanied with arterial hypotension, protected cerebral micro-vasculatures from damaging effects of acute stroke. Key Words: Blood–brain barrier, Brain edema, AT1 receptor, Candesartan 相似文献
72.
Bakhshi B Pourshafie MR Navabakbar F Tavakoli A Shahcheraghi F Salehi M Faradjzadegan Z Zahraei SM 《Iranian Biomedical Journal》2008,12(3):159-165
Background: The virulence of a pathogenic Vibrio cholerae is dependent on a discrete set of genetic determinants. In this study, we determined the distribution of virulence determinants among the clinical and environmental isolates of V. cholerae. Methods: The antibiotic resistance profiles of the isolates were determined using standard disk diffusion assay. PCR assay was performed to analyze the presence of toxin genes of ctx, zot and ace. The composition of cholera toxin encoding element (CTX) region flanking of the V. cholerae isolates was also analyzed. Results: All of the clinical isolates (100%) showed a complete set of virulence genes and also the attachment site of the filamentous bacteriophage CTXphi. None of the environmental isolates contained the virulence genes and the attachment site of the CTXphi. Analysis of the flanking regions including the toxin-linked cryptic element and repeat in toxin genes revealed their integrity in the clinical isolates while in the environmental isolates they were absent or contained incomplete sequences. Comparison of the antibiotic resistance assay of the environmental and clinical isolates showed a significant difference in the resistance profiles of the isolates obtained from the two sites. High rates of resistance to co-trimoxosol, streptomycin and chloramphenicol were found with clinical isolates. Conclusion: The absence of all virulence determinants in the environmental strains may suggest that certain ecological features must be present for V. cholerae to acquire a complete set of virulence determinants and to turn them into pathogenic strains. 相似文献
73.
Safaeian S Amirsharifi M Esmaeili A Salimi L 《Pakistan journal of biological sciences: PJBS》2008,11(4):668-671
Metasystox-R is a systemic soluble liquid insecticide for the control of aphids on brassica vegetable crops, cotton and lupins and it is possible enter to the marine environment and may be have a hazard effects for the marine organisms and nitrification processes. Effect of Metasystox-R on ammonia oxidizing activity by marine Nitrosomonas sp. was investigated by determining nitrification inhibitor assay in the cell suspension. Results showed that 8 microg mL(-1) of Metasystox-R with PI50 = 4.48 significantly inhibited nitrite production by marine Nitrosomonas sp. These results suggested marine Nitrosomonas sp. may be one of the target bacteria which was inhibitor and decreasing nitrification in the marine environment. 相似文献
74.
Zafar Iqbal Sohail Hameed Muhammad Akbar Anjum Altaf Ahmad Dasti Ahmad Saleem 《European journal of plant pathology / European Foundation for Plant Pathology》2010,127(3):391-398
Aetiology of mango malformation (MM) has intrigued the scientists since its inception. The objective of the study was to glean
an insight into association of the fungus, Fusarium mangiferae, with different malformed regions, viz. panicle-shoot juncture, apical buds, primary and secondary peduncles, in five exotic
mango cultivars. Tissue assays revealed an infection of 88.5, 84.75 and 82.5% in cvs Zill, Sensation and Tommy Atkins, respectively.
Least infection of 69.75% was found in cv. Keitt. No exotic cultivar was found to be free of fungal infection. Apical buds
proved to be the potential infection site of the fungus amongst the four malformed regions, hosting maximum within-tissue
infection of 86.2%. Determination of F. mangiferae at proximal and distant sites of the malformed panicles exhibited maximum recovery of 82.0% at 0 cm and only 3% at >30 cm
distance beneath the panicle. In the case of non-malformed panicles, an infection of 14.0% was recorded at 0 cm distance while
no detection could be made from non-malformed branches. Moreover, examination of ultra-thin bud sections under Transmission
Electron Microscopy (TEM) revealed inter- and intra-cellular ramification of fungal hyphae, indicating fungal ingress in malformed
bud tissues of local cv. Malda. The present studies explored the sites hosting the causal fungus in mango and provide convincing
evidence that F. mangiferae is responsible for turning healthy tissues into the malformed condition. These findings suggest that inoculum specific management
strategies are needed in future to curb malformation disease in mango orchards. 相似文献
75.
利用光学显微镜(LM)和扫描电镜(SEM),对新疆昆仑山2科4属10种藓类孢子进行了观察。结果表明:所研究种类孢子体积小、孢壁薄、易褶皱、纹饰明显。同科属之间,孢子的形态、直径、近极面结构,特别是外壁纹饰的形状、分布均有差异。该研究可为苔藓植物系统分类、演化及化石孢子的鉴定提供依据。 相似文献
76.
BACKGROUND: Biopesticides based on Beauveria bassiana (Bals.) Vuillemin hold great promise for the management of a wide range of insect pests. The conidia in the biopesticide formulation require an adjuvant to protect them from photoinactivation by sunlight. The suitability of Tinopal, an optical brightener used as sunscreen for baculovirus formulations, for use with B. bassiana was assessed. The aim was to study the effect of Tinopal on the growth and photoprotection of B. bassiana, and its effect on the susceptibility of insects to B. bassiana. RESULTS: Tinopal was found to have no adverse effect on the growth of B. bassiana. It was found to confer total protection (approximately 95% conidial germination at 10 g Tinopal L(-1)) from sunlight up to 3 h of exposure, and a better survival rate than controls even up to 4 h. Helicoverpa armigera Hübner larvae fed on diet with 5 g kg(-1) Tinopal were found to have reduced growth. The duration of the larval stage increased by 3-4 days in 1 and 5 g kg(-1) Tinopal treatments. Among the moths that emerged from larvae fed on diet with 5 g kg(-1) Tinopal, a significantly high number were malformed compared with controls. The larvae that were fed diet with Tinopal showed quicker and higher mortality and required a lower effective lethal dose (LC(50)) than the controls. Tinopal was found to have a synergistic effect with B. bassiana in causing insect mortality. CONCLUSIONS: Tinopal was found to be a suitable adjuvant for B. bassiana-based biopesticide formulations. It conferred tolerance to sunlight and caused stress in the insect, leading to a synergistic effect with B. bassiana. 相似文献
77.
78.
Effect of trees on the yield of wheat crop 总被引:3,自引:0,他引:3
A study was conducted at the National Agricultural Research Center (NARC) of Pakistan Agricultural Research Council (PARC) by planting trees of four different species: Eucalyptus camaldulensis, Albizia procera, Morus alba and Leucaena leucocephala along the boundary of wheat fields in a randomized complete block design. Data on crop yield for each tree species and control (no trees) at different distances viz 2, 4, 6, 8, 10 and 12 meter (m) from the tree bases and control were collected and analyzed. The statistical analysis did not show any significant difference in the wheat yield among different tree species. However, the wheat yield was numerically lowest at 2 m distance in case of all the four tree species and control. In case of mulberry, it was lowest statistically also from other distances. Numerically higher wheat yield values were noted at later distances (8, 10 and 12 m) in case of all tree species including control except for siris where numerically highest value was found at 6 m distance. Therefore, it can be generalized that tree's impact on wheat yield can be experienced up to 2 m distance, there is little, if any, impact up to 6 m distance and almost no impact at 8, 10 and 12 m distances. 相似文献
79.
Inheritance pattern of mungbean yellow mosaic disease resistance and gene action for different traits in mungbean (Vigna radiata (L.) Wilczek) under protected and unprotected field conditions 下载免费PDF全文
Waseem Akbar Muhammad Aslam Muhammad Amir Maqbool Muhammad Ali Muhammad Arshad 《Plant Breeding》2018,137(5):763-772
Understanding of mungbean yellow mosaic disease resistance is crucial to develop resistant varieties to combat worldwide threat of the disease epidemics. This study was aimed to determine nature of disease resistance in terms of number of genes governing it and genetics of related traits. Experimental site was located on 31.43°N and 73.06°E with an elevation of 186 m, and evaluation trials were conducted during spring season due to high disease epidemics in this season. Two contrasting genotypes, that is, NM 6‐68‐2 (resistant) and NM 1‐32‐1 (highly susceptible), were crossed to raise six populations, that is, P1, P2, F1, F2, BC1 and BC2 for evaluation under protected and unprotected field conditions using chi‐square test and generation mean and variance analysis. It was discovered that disease resistance was governed by two major genes with additive effects. Disease resistance can easily be incorporated through backcrossing and direct selection following hybridization. Direct selection should be practised at earlier generation for plant height, chlorophyll contents and number of seeds per pod due to preponderance of additive effects whereas at later generations for seed yield per plant, 100 seed weight, harvest index, number of pods per plant and pod length due to involvement of duplicate epistasis. 相似文献
80.
Amir Hossein Alavi Amir Hossein Gandomi Ali Mollahassani Ali Akbar Heshmati Azadeh Rashed 《植物养料与土壤学杂志》2010,173(3):368-379
This study considers the use of artificial neural networks (ANNs) to predict the maximum dry density (MDD) and optimum moisture content (OMC) of soil‐stabilizer mix. Multilayer perceptron (MLP), one of the most widely used ANN architectures in the literature, is utilized to construct comprehensive and accurate models relating the MDD and OMC of stabilized soil to the properties of natural soil such as particle‐size distribution, plasticity, linear shrinkage, and the type and quantity of stabilizing additives. Five ANN models are constructed using different combinations of the input parameters. Two separate sets of ANN prediction models, one for MDD and the other for OMC, and also a combined ANN model for multiple outputs are developed using the potentially influential input parameters. Relative‐importance values of various inputs of the models are calculated to determine the significance of each of the predictor variables to MDD and OMC. Inferring the most relevant input parameters based on Garson's algorithm, modified ANN models are separately developed for MDD and OMC. The modified ANN models are utilized to introduce explicit formulations of MDD and OMC. A parametric study is also conducted to evaluate the sensitivity of MDD and OMC due to the variation of the most influencing input parameters. A comprehensive set of data including a wide range of soil types obtained from the previously published stabilization test results is used for training and testing the prediction models. The performance of ANN‐based models is subsequently analyzed and compared in detail. The results demonstrate that the accuracy of the proposed models is satisfactory as compared to the experimental results. 相似文献