1,085 research outputs found
Analytic height correlation function of rough surfaces derived from light scattering
We derive an analytic expression for the height correlation function of a
rough surface based on the inverse wave scattering method of Kirchhoff theory.
The expression directly relates the height correlation function to diffuse
scattered intensity along a linear path at fixed polar angle. We test the
solution by measuring the angular distribution of light scattered from rough
silicon surfaces, and comparing extracted height correlation functions to those
derived from atomic force microscopy (AFM). The results agree closely with AFM
over a wider range of roughness parameters than previous formulations of the
inverse scattering problem, while relying less on large-angle scatter data. Our
expression thus provides an accurate analytical equation for the height
correlation function of a wide range of surfaces based on measurements using a
simple, fast experimental procedure.Comment: 6 pages, 5 figures, 1 tabl
The granule cell density of the dentate gyrus following administration of Urtica dioica extract to young diabetic rats
Urtica dioica L. Stinging nettle has long been known worldwide as a medicinal plant. To study the benefits of the nettle in diabetic encephalopathy, the granule cell density of the dentate gyrus of diabetic rats was studied following administration of Urtica dioica extract. A total of 24 male albino Wistar rats were allocated equally to normal, diabetic, preventive and treatment groups. Hyperglycaemia was induced by streptozotocin (80 mg/kg) in the animals of the diabetic and treatment groups. One week after injection of the streptozotocin the animals in the treatment group received a hydroalcoholic extract of Urtica dioica (100 mg/kg/day) for 4 weeks intraperitoneally. The rats of the preventive group received hydroalcoholic extract of U. dioica (100 mg/kg/day) IP for the first 5 days and an injection of streptozotocin (80 mg/kg) on the 6th day. After 5 weeks of study all the rats were sacrificed and coronal sections were taken from the dorsal hippocampal formation of the right cerebral hemispheres and stained with cresyl violet. The area densities of the granule cells were measured and compared in the four groups. The density was lower in the diabetic rats compared with the controls (p > 0.05). The preventive group showed lower cell density than the controls (p > 0.05). The densities in the treated rats were higher than in the diabetic rats (p > 0.05). Furthermore, the control and treated rats showed similar densities (p > 0.05). It seems that U. dioica extract can help compensate for granule cell loss in the diabetic rat dentate gyrus, which can ameliorate cognitive impairment in diabetes. However, preventive use of the extract showed no significant benefit. Copyright © 2008 Via Medica
Resistance of CA1 pyramidal cells to STZ-induced diabetes in young rats
The pyramidal cell density of CA1 hippocampal subfield following STZ-induced diabetes in young rats were studied. 12 male albino 6-week Wistar rats were allocated equally in groups of normal and diabetic. Hyperglycemia induced by Streptozotocin (80 mg/kg) in animals of diabetic group. After 5 weeks of study, all the rats were sacrificed and coronal sections were taken from dorsal hippocampal formation of the right cerebral hemispheres and stained with crysel violet. The area densities of the CA1 pyramidal cells were measured and compared among two groups. No significant difference between the densities of two experimental groups was found. The results can arise from the short period of diabetes and also the possible regenerative processes in developing brain of the young diabetic rats which compensated significant diabetes-induced neuronal loss
Determination of heavy metals content in Astacus leptodactylus caspicus in Anzali Lagoon
With attention to different human activities around Anzali lagoon and entrance different pollutants containing heavy metals into this aquatic ecosystem and alterante absorption and accumulation of heavy metals in shell and muscle of Astacus leptodactylus which is native species of Anzali lagoon and having food and economic importance. Sampling of water and sediments from 18 stations and also shell and muscle of Astacus leptodactylus from 5 stations have been conducted. After biometric evaluation of Astacus leptodactylus, the chemical analysis of the samples were done by using international standard methods and then their heavy metals content was determined by Atomic Absorption Spectrophotometer (A.A.S). Result of the analysis stated that: There wasn't significant difference between weight and size of Astacus leptodactylus with their absorption and accumulation of heavy metals; but there was a significant difference and correlation coefficient between heavy metals content in water and sediments, and also in sediments with shell and muscle of Astacus leptodactylus in Anzali lagoon
Effect of Aloe vera on some indicators of cell damage after a period of aerobic exercise in male athletes
Introduction: Aloe vera is a medicinal plant with antioxidant activity. The purpose of this study was to determine the effect of Aloe vera on some indicators of cell damage after a period of aerobic exercise in male athletes of 15-18 years old. Methods: In this clinical trial study, 20 male students with average weight of 64.85 ± 51 and height of 172.05 ± 6.4 were randomly assigned to 2 groups of Aloe vera supplement (n = 10) and placebo (n = 10). Then aerobic training was conducted for 4 weeks. The supplemented group took 3 capsules, each capsule contains 2 g of dried Aloe vera and placebo group took 3 capsules/day containing dextran after every meal. To determine the index of cell injury markers creatine kinase (CK), lactate dehydrogenase (LDH) and reactive protein C (CRP) were determined and blood samples were collected 24 hours before and after each test. The data were analyzed using ANOVA and independent t test. Significance level was considered as P ≤ .05. Results: The use of Aloe vera during aerobic exercise significantly reduced LDH (P = .006) in the supplement group (15 reduction) compared to placebo group and CRP with 11 reduction in the supplement group compared to placebo (P = .008). There was no significant reduction in CK. Conclusion: The findings of this study showed that Aloe vera reduces cell damage and inflammation indicators. This result may reflect the role of Aloe vera as anti-inflammatory and antioxidant agent.</p
Развитие научных основ новых методов интенсификации процессов тепломассообмена в рабочих средах воздействием силовых полей периодической интенсивности
Проведено оглядовий аналіз результатів досліджень, виконаних у відділі високотемпературної теплотехніки ІГТМ НАНУ з впливу вібраційних полів на тепломассоперенос в рідких робочих середовищах у великому об'ємі, каналах і пористих структурах.Results of research performed in the department of high-temperature heat engineering of IGTM NAS of Ukraine on the effect of vibration on the heat and mass transfer in liquid working media, in a large volume in channels and in porous structures are reviewed
Effect of polymer and irrigation regimes on dry matter yield and several physiological traits of forage sorghum
Drought stress is one of the most serious problems in crops production in the arid and semi-arid regions. Application of some materials such as superab A200 polymers (SAP) in soil can improve soil water reservation. They can also decrease water losses, fertilizer leaching in soils, effects of water deficiency in plants and so can improve the yield in the arid and semi-arid regions. This experiment was conducted on forage sorghum (Sorghum bicolor (L.) variety ‘Speedfeed’) in Zahedan, Iran during 2010 season. The experimental design was a split-plot with two factors including four irrigation regimes (providing 40, 60, 80 and 100% of the water requirement of sorghum calculated from pan evaporation) as main plots and four amounts of SAP (0, 75, 150 and 225 kg ha-1) as subplots in a completely randomized block design with three replications. Irrigation level and SAP had significant effects on chlorophyll index, leaf area index, leaf area duration, crop growth rate, relative water content and dry matter. The results indicate that irrigation to meet 80% of the water requirement with 75 kg ha-1 SAP which may provide a desirable dry matter.Keywords: Dry matter yield, forage sorghum, growth analysis, irrigation regime, superab A200 polyme
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