1,792 research outputs found

    Effects of brassinosteroid (24-epibrassinolide) on yield and quality of grape (Vitis vinifera L.) 'Thompson Seedless'

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    Berry growth ripening process and yield are directly related with nutrition status and phytohormones during fruit growth and development stages. Brassinosteroid (24-epibrassinolide) is one of the plant growth substances that influence different physiological processes including fruit growth and development. In this study, the effect of brassinosteroid (Br) application on the yield and berry quality of 'Thompson Seedless' was investigated in a commercial vineyard, Malayer, Hamedan, Iran. Br solution concentrations of 0, 0.2, 0.4, 0.6 mg·L-1 at five stages (budbreak (S1), prebloom (S2), middle of bloom (S3), post bloom (S4) and veraison (S5) were sprayed. The results showed that the Br application has significant positive effects on bunch morphology and berry quantity and quality. Among levels of Br, the highest yields were related to the application of Br at the rate of 0.6 mg·L-1 in the post bloom and veraison stages, and the lowest was found in the bud break stage. Spraying Br in the post bloom and veraison stages had the greatest effect on berry quality. Also, the highest content of total phenol and antioxidant capacity were obtained with 0.6 mg·L-1 of Br application at veraison stage. In this study, we provided evidence to show that using steroidal plant hormones (Br) may play an essential role in improving the yield and quality of 'Thompson Seedless'

    Altered pituitary hormone secretion in male rats exposed to Bisphenol A

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    Bisphenol A (BPA) is a xenobiotic estrogenic compound. This compound has been suspected to have estrogenic effects on reproductive system of males and females. In this present study we investigated possible low-dose effects of BPAon Luteinizing Hormone in rats. Male Wistar rats (12-13 weeks old) were administrated a daily intra peritoneal 10 μg/kgbw/day, 50 μg/kgbw/day, 100 μg/kgbw/ day dose of BPA for 6, 6, and 12 days, and one day after last injection, serum level of Luteinizing Hormone was examined by ELISA method. All data were expressed as means ± SE. Two-way ANOVA was performed. Analysis of data showed that in all dose groups, plasma level of Luteinizing Hormone significantly decreased compared to control group. The present study showed that BPA at low doses affects Luteinizing Hormone, one of main hormones in spermatogenesis in the adult Wistar rats, and subsequently alters the steroidgenesis in testicular Leydig cells

    Enhanced tunability of magnetron sputtered Ba[sub 0.5]Sr[sub 0.5]TiO[sub 3] thin films on c-plane sapphire substrates

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    Thin films of Ba0.5Sr0.5TiO3 (BST) were deposited on c-plane (0001) sapphire by rf magnetron sputtering and investigated by complementary materials analysis methods. Microwave properties of the films, including tunability and Q factor were measured from 1 to 20 GHz by patterning interdigital capacitors (IDCs) on the film surface. The tunability is correlated with texture, strain, and grain size in the deposited films. An enhanced capacitance tunability of 56% at a bias field of 200 kV/cm and total device Q of more than 15 (up to 20 GHz) were achieved following postdeposition annealing at 900°C

    Effect of Extract of Aerial Parts of Urtica dioica (Urticaceae) on the Stability of Soybean Oil

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    Purpose: To evaluate the effectiveness of Urtica dioica (Urticaceae) extract as a natural antioxidant and compare with the most commonly used synthetic antioxidants, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT).Methods: Three different U. dioica extracts, viz, chloroform, methanol (80 %) and water extracts, were prepared. The antioxidant activity of the extracts were evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging and soybean oil models. Varying concentrations of the extracts (200, 500 and 800 ppm), BHA and BHT (100 and 200 ppm) were separately added to soybean oil and stored in the oven (60±1 °C) for 25 days. Peroxide and thiobarbituric acid (TBA) values were measured at various heating periods for the oil samples. Total phenolic and flavonoid contents of the extracts were determined using Folin–Ciocalteu and aluminium chloride methods, respectively, while the aerial parts of the plant were also phytochemically screened.Results: Analysis of the chemical composition of U. dioica aerial parts showed they contain crude proteins (21.78 %±0.11), crude lipids (1.66 %±0.03), total soluble carbohydrates (37.19 %±0.21), crude fibers (19.62 %±0.14) and ash (19.75 %±0.17). The aqueous extract contained the highest level of total phenolic contents (7.89 ±0.38, mg g-1 of powder) while the choroform extract contained the highest level of flavonoid contents (15.40 ±0.53 mg g-1 powder). The half-maximal concentration (IC50) values for chloroform, methanol (80 %) and aqueous extracts in respect of DPPH radical scavenging activity were 77.53±0.99, 199.71±1.02 and 159.88±1.57 μg ml-1, respectively. Mixing soybean oil with 200 - 800 ppm of extract decreased oil oxidation and formation rate of TBA reacting substances at a level that is almost equivalent to the synthetic antioxidant, BHT, at a concentration of 200 ppm.Conclusion: These findings demonstrate that mixing soybean oil with U. dioica extract can improve the quality of the oil during frying process.Keywords: Antioxidant activity; Soybean oil; DPPH; Peroxide value; Thiobarbituric acid value; Urtica dioic

    Patient Satisfaction With the Family Physician Program in Sabzevar, Iran

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    BACKGROUND AND OBJECTIVES: Patient satisfaction with the family physician program is an important factor for more favorable treatment results. Evaluation of patient satisfaction improves the services and approximates them to patient's preferences. The family physician program has been executed since late March, 2005 in Iran. This study aimed to measure patient satisfaction with family physician services and determines factors affecting the level of satisfaction in order to propose appropriate suggestions for providing medical services based on patients' expectations. METHODS: Forty-one centers provide healthcare services in rural and urban areas. The participants in this study comprised 1263 people. The data were collected by an inventory with 11 items about demographic specifications, waiting time and the importance of physician's sex and 40 items for assessing the level of patient satisfaction. RESULTS: A total of 1199 patients participated in the current study, 72.1 of them were female and 19.6 waited 10-20 minutes for receiving services. About 55.72 of the participants chose high and very high for the items of the inventory. Total satisfaction with the family physician program decreased with age (p-value=0.029).Moreover, total satisfaction did not show any significant differences in different groups in terms of sex, place of residence, education level and marital status. Also family physicians' sex did not affect patient satisfaction significantly. Based on results of regression model, an increase in patients' age by one year decreased their satisfaction by 0.12 and level of satisfaction in rural patients was lower than that in urban patients by 7.93. CONCLUSIONS: The level of patient satisfaction with family physician services was moderate, which mostly arose from the components of the family physician program and services such as the waiting time, costs, welfare facilities, accessibility and the service-providing team rather than patients' personal characteristics

    Effect of Biochar Type, Concentration and Washing Conditions on the Germination Parameters of Three Model Crops

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    Biochar has been recognized as a promising and efficient material for soil amendment. However, its effects on seed germination are variable due to its alkaline pH and/or the presence of phytotoxic substances. In this study, two types of biochar (B1 and B2) were mixed with soil at different concentrations (0%, 5%, 10%, 25%, 50% and 100%, w:w), and both the solid and liquid fractions of these mixtures were tested on the germination of basil, lettuce and tomato seeds. Furthermore, solid fractions subjected to a pre-washing treatment (B1W and B2W) were also investigated for their effects on seed germination. Three germination parameters were then measured: seed germination number (GN), radicle length (RL) and germination index (GI). Biochar B2W at 10% increased both RL and GI in basil by 50% and 70%, respectively, while B1 at 25% increased these parameters in tomato by 25%. No effects or negative effects were recorded for lettuce. Liquid fractions (L1 and L2) generally hampered seed germination, suggesting the presence of potentially water-soluble phytotoxic compounds in biochar. These results point to biochar as a suitable component for germination substrates and highlight that germination tests are critical to select the best performing biochar according to the target crop

    Modelling the induced polarization of bentonite-sand mixtures

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    International audienceSpectral induced polarization (SIP) has become an increasingly popular geophysical method for hydrogeological and environmental applications. These applications include for instance the non-intrusive characterization of the textural and interfacial physicochemical properties of bentonites used as permeability barriers in landfills or to store various types of contaminants including radioactive wastes. Bentonites are mainly constituted of smectites, which have very high specific surface areas (SSA) and cation exchange capacities (CEC). Therefore, these minerals have very high electromigration and polarization current densities responsible for very high in phase and quadrature conductivities, respectively. In addition, in diluted water, the diffuse layer of smectites occupies a large fraction of the pore space and may be therefore considered as part of the pore space. In our approach [1], complex electrical conductivities of saturated unconsolidated bentonite and bentonite-sand mixtures are modeled at different salinities (NaCl) of the bulk pore water using a Donnan equilibrium model coupled to the revisited SIP model of Leroy and Revil [2]. Our complex surface conductivity model considers the DC contribution of the diffuse and Stern layers as well as the electrochemical polarization of the Stern layer coating the grains with different sizes. The macroscopic SIP model is based on the differential effective medium theory and considers the complex surface conductivity of the sand and smectite grains and the complex conductivity of the pore space. In our model, the diffuse layer of quartz sands occupies a small fraction of the pore space and is considered therefore as part of the surface of the grains. Our SIP model predicts very well the low frequency (0.1 Hz - kHz) complex electrical conductivities of bentonite and bentonite-sand mixtures, except for very low frequencies (< 0.1 Hz) where membrane polarization may occur (Figure 1). The in phase conductivity of the sample with a high clay content (20 % in volume) increases slowly with salinity because of the very high DC surface conductivity of smectite. The observed large increase of the in phase and quadrature conductivity of the samples with the clay content (1, 20 and 100% in volume) is also predicted by our model. The quadrature conductivity of the samples with a high clay content is fairly independent on the pore fluid salinity because it is strongly connected with the SSA, CEC and Stern layer of smectite (Figure 1). The in phase conductivity of the sample with a low clay content (1% in volume) increases quickly with the salinity because of its low DC surface conductivity. Its quadrature conductivity also increases quickly with salinity because of the formation of the Stern layer at the surface of quartz sand. Nevertheless, our SIP model can't predict the quadrature conductivity spectra observed at very low frequencies (< 10-1 Hz). The missing polarization mechanism may correspond to membrane polarization and there is an effort to be done to incorporate this contribution in a unified model
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