433 research outputs found

    Influence of Salicylic Acid on the Antimicrobial Potential of Stevia (Stevia rebaudiana Bertoni, Asteraceae) Leaf Extracts against Soybean Seed-Borne Pathogens

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    Purpose: To investigate the effect of salicylic acid (SA) on the antimicrobial profile of Stevia leaf extracts against soybean seed-borne pathogens.Methods: Stevia seeds were planted in a greenhouse and SA foliar applied after six weeks on the whole plant at concentrations of 0 and 0.1 g L-1. The extracts of the plant leaf were separately obtained using four different solvents (water, acetone, ethanol and chloroform), and the oil composition of the extracts determined by gas chromatography-mass spectrophotometry (GC-MS). The antibacterial and antifungal potentials of each of the extracts were examined against 11 selected pathogens responsible for soybean seed and seedling diseases.Results: Chloroform extracts had the highest amount of α-cadinol, spathulenol, caryophyllene oxide, methyl salicylate and safranal in the SA-treated plants, and were 8, 10, 18, 14 and 11 %, respectively, higher than the non-SA treated control. In the anti-microbial tests, chloroform extract exhibited the highest diameter of inhibition zone (max 18 mm) against all the tested microorganisms while water extract showed the least effect (max 9 mm), with no effect at all on two fungi (Phomopsis spp and Cercospora kikuchii) and two bacteria (Pseudomonas syringae and Xanthomonas campestris). All extracts with or without SA had no effect on Xanthomonas campestris. SA treatment enhanced the antimicrobial potential of all extracts in the pathogenicity test compared with untreated plant extracts.Conclusion: Stevia leaf extract has antimicrobial effect against soybean seed-borne disease if applied on the seed before planting. Application of SA on the Stevia plant substantially enhances the antimicrobial activity of the leaf extract thus affording the seeds greater protection.Keywords: Stevia, Antimicrobial, Salicylic acid, Soybean, Pathogens

    Ranking Iranian biomedical research centers according to Hvariants (G, M, A, R) in Scopus and Web of Science

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    Background: We conducted a comprehensive bibliometrics analysis to calculate the H, G, M, A and R indicators for all Iranian biomedical research centers (IBRCs) from the output of ISI Web of Science (WoS) and Scopus between 1991 and 2010. We compared the research performance of the research centers according to these indicators. Methods: This was a cross-sectional and descriptive-analytical study, conducted on 104 Iranian biomedical research centers between August and September 2011. We collected our data through Scopus and WoS. Pearson correlation coefficient between the scientometrics indicators was calculated using SPSS, version 16. Results: The mean values of all indicators were higher in Scopus than in WoS. Drug Applied Research Center of Tabriz University of Medical Sciences had the highest number of publications in both WoS and Scopus databases. This research center along with Royan Institute received the highest number of citations in both Scopus and WoS, respectively. The highest correlation was seen between G and R (.998) in WoS and between G and R (.990) in Scopus. Furthermore, the highest overlap of the 10 top IBRCs was between G and H in WoS (100) and between G-R (90) and H-R (90) in Scopus. Conclusion: Research centers affiliated to the top ranked Iranian medical universities obtained a better position with respect to the studied scientometrics indicators. All aforementioned indicators are important for ranking bibliometrics studies as they refer to different attributes of scientific output and citation aspects

    The effect of aquaculture effluents on water quality parameters of Haraz River

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    In this study, a water quality model of Haraz basin was used as an evaluative tool to estimate the spatial distribution of variables that are related to water quality and nutrient loads of the Haraz River. Previous studies performed in this river indicate that trout culture activity along the Haraz River have led to various changes in the water quality parameters. In the present work, the possible effects of two additional fish farms with a production capacity of 50 tons, located on the Haraz within 1 km distance from each other were evaluated in terms of their effects on the streams water quality. A water quality model was developed in order to investigate the spatial distribution of water quality variables. The model also used to estimate the dissolved oxygen (DO), biological oxygen demand (BOD5) and nutrients along the stream

    The Study of Cognitive Function and Related Factors in Patients With Heart Failure

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    Background: Cognitive impairment is increasingly recognized as a common adverse consequence of heart failure. Both Heart failure and cognitive impairment are associated with frequent hospitalization and increased mortality, particularly when they occur simultaneously. Objectives: To determine cognitive function and related factors in patients with heart failure. Materials and Methods: In this descriptive cross-sectional study, we assessed 239 patients with heart failure. Data were collected by Mini Mental status Examination, Charlson comorbidity index and NYHA classification system. Data were analyzed using descriptive statistics, Kolmogorov-Smirnov test, chi-square test, t-test and logistic regression analysis. Results: The mean score of cognitive function was 21.68 ± 4.51. In total, 155 patients (64.9%) had cognitive impairment. Significant associations were found between the status of cognitive impairment and gender (P < 0.002), education level (P < 0.000), living location (P < 0.000), marital status (P < 0.03), living arrangement (P < 0.001 ), employment status (P < 0.000), income (P < 0.02), being the head of family (P < 0.03), the family size (P < 0.02), having a supplemental insurance (P < 0.003) and the patient’s comorbidities (P < 0.02). However, in logistic regression analysis, only education and supplementary insurance could predict cognitive status which indicates that patients with supplementary insurance and higher education levels were more likely to maintain optimal cognitive function. Conclusions: More than a half of the subjects had cognitive impairment. As the level of patients cognitive functioning affects their behaviors and daily living activities, it is recommended that patients with heart failure should be assessed for their cognitive functioning

    Hafnia and alumina on sulphur passivated germanium

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    In this work hafnia (HfO2) and alumina (Al2O3) films were deposited on germanium, using either water or oxygen plasma as the oxidant, by atomic layer deposition at 250 °C with and without sulphur passivation of the substrate. X-ray photoelectron spectroscopy was carried out to investigate the interface between both HfO2 and Al2O3 films and germanium. The results show that for hafnia and alumina deposited with water on pre-sulphur treated germanium there is negligible GeOx formation when compared to films grown using oxygen plasma. The results support the case for sulphur passivation of the interface
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