12 resultados para transient leaf assay
em Cochin University of Science
Resumo:
Alloxan induced animal model was used to evaluate the potential antidiabetic effect of A . marmelose leaf extract. The diabetic animals were given insulin injection and another group A . marmelose leaf extract orally. It maintained the weight of the animals near to the control rats but a significant decrease in weight was noted it diabetic animals without any treatment . The blood elucose level in 'treated animals were near to that of control ones. Also a significantly increased glucose tolerance was observed in animals orally given the leaf extract prior to the experiment . A significant decrease in liver glycogen ( 1.24 -.07 s!/ 100 g of wet tissue) was observed in diabetic rats which was brought to almost the normal level (I.84- . 14 g; 100 g) with Icaf extract treatment. Blood urea and serum cholesterol increased ( 62.66 - 3.50 and 192.67± 13.64 mg' dl) significantly in alloxxan diabetic rats . The leaf extract treatment decreased the blood urea and serum . cholesterol (37.83 - 3.97 and 99?0±8.43 mg/dl ) to that of control ones . A similar effect was seen with insulin treatment . The results indicate that the active principle in .4. marmelose leaf extract has similar hypoglycaemic activity to insulin treatment.
Resumo:
Alloxan induced diabetic animal model was sed to evaluate the potential antidiabetic effect of ie aqueous leaf extract of Aegle marmelose. Insuinjection and oral treatment of Aegle marmelose of extract to the alloxan induced rats maintained ;e animal weight near to the control rats whereas ,,ere was a significant decrease in weight in alloxan •duced rats. Insulin injection and oral treatment the leaf extract reversed the decrease of protein )ntent in all the organs studied except the pancas. Glucose level was maintained near to the co- :rol levels in the insulin injected and leaf extract Bated alloxan diabetic rats. A significant increased ucose tolerance was observed in animals orally ven the leaf extract prior to the experiment. The suits indicate that there is an increased utilization glucose in the Aegle marmelose leaf extract treed rats.
Resumo:
The functional basis of diabetes-mellitus to a certain extent, can be elucidated by studying diabetes-induced changes in metabolic enzymes. Malate dehydrogenase (MDH), is an enzyme directly involved in glucose metabolism. The kinetic parameters of MDH and its purified cytosolic isozyme, S-MDH, have been studied in the liver of streptozotocin- diabetic rats; also the potential of the leaf extract of A. marmelose as an was investigated. The Km of the liver enzyme increased significantly, in both crude and purified preparations in the diabetic state when compared to Lhe respective controls. Insulin as well as leaf- •extract treatment of the diabetic rats brought about a reversal of K. values to near normal. Vmax of purified S-MDH was significantly higher in the diabetic state when compared to the control. Insulin and leaf extract treatment did not reverse this change. Since MDH is an important enzyme in glucose metabolism, the variation in its quantitative and qualitative nature may contribute to the pathological status of diabetes. The fact that leaf extract of A. marmelose was found to be as effective as insulin in restoration of blood glucose and body weight to normal levels, the use of A. marmelose as potential hypoglycemic agent is suggested.
Resumo:
The transient interaction between a refraction index grating and light beams during simultaneous writing and thermal fixing of a photorefractive hologram is investigated. With a diffusion- and photovoltaic-dominated carrier transport mechanism and carrier thermal activation (temperature dependent) considered in Fe:LiNbO3 crystal, from the standpoint of field-material coupling, the theoretical thermal fixing time and the space-charge field buildup, spatial distribution, and temperature dependence are given numerically by combining the band transport model with mobile ions with the coupled-wave equation
Resumo:
The transient characteristics of an erbium-doped fiber (F.DF) laser, which can switch between wavelengths. are investigated. 77te laser has a set of coupled linear cavities. The slow gain dynamics of EDFs and the cross-gain saturation in the coupled cavities give rise to delayed switching responses and relocation oscillations, which are respertively measured to be l ins and 3.5 ms for the worst rase, and which mar be decreased by increasing the pump power. Thus, the switching speed of the laser may be higher than 100 Hz
Resumo:
Thermal diffusivity measurements are carried out in certain organic liquids using the pulsed dual beam thermal lens technique. The 532 nm pulses from a frequency doubled Q-switched Nd:YAG laser are used as the heating source and an intensity stabilized He-Ne laser serves as the probe beam. Experimental determination of the characteristic time constant of the transient thermal lens signal is verified theoretically. Measured thermal diffusivity values are in excellent agreement with literature values.
Resumo:
Dual-beam transient thermal lens studies were carried out in aqueous solutions of rhodamine 6G using 532 nm pulses from a frequency-doubled Nd:YAG laser. The analysis of the observed data showed that the thermal lens method can effectively be utilized to study the nonlinear absorption and aggregation which are taking place in a dye medium.
Resumo:
The present work is to understand the alterations of total Muscarinic and Muscarinic MI receptors in brain and pancreatic islets of Streptozotocin induced diabetic rats. The work focuses on the evaluation of the antihyperglycemic activity of aqueous extracts of Aegle marmelose and Costus pictus leaves in vivo and the changes in the total Muscarinic and Muscarinic MI receptors during diabetes and after the treatment with insulin. The insulin secretory activity of Aegle marmelose and Costus pictus leaf extracts and the effect of cholinergic receptor agonist were investigated in vitro using rat primary pancreatic islet culture. Muscarinic MI receptor kinetics and gene expression during diabetes and regulation of insulin secretion by Aegle marmelose and Costus pie/us leaf extracts will help us to elucidate the role of Muscarinic and Muscarinic MI receptors in hyperglycemia and the regulatory activity of these plant extracts on insulin secretion through Muscarinic receptors.
Resumo:
Dual beam thermal lens tecbnique is successfully employed for the determination of absolute Fluorescence quantum yield of rhodamine 6G lnser dye in different solvents. A 532 nm radiation from a Q-switched Nd:YAG laser was used for the excitation purpose. The fluorescence quantum yield values are found to be strongly influenced by environmental effects. It has been observed that fluorescence yield is greater for rhodamine 6G in ethylene glycol system than in water or in methanol. Our results also indicate that parameters like concentration of the dye solution, aggregate formation and excited state absorption affect the absolute values of fluorescence yield significantly.
Resumo:
A major challenge in the transmission of narrow pulses is the radiation characteristics of the antenna. Designing the front ends for UWB systems pose challenges compared to their narrow and wide band counterparts because in addition to having electrically small size, high efficiency and band width, the antenna has to have excellent transient response. The present work deals with the design of four novel antenna designs- Square Monopole, Semi-Elliptic Slot, Step and Linear Tapered slot - and an assay on their suitability in UWB Systems. Multiple resonances in the geometry are matched to UWB by redesigning the ground-patch interfaces. Techniques to avoid narrow band interference is proposed in the antenna level and their effect on a nano second pulse have also been investigated. The thesis proposes design guidelines to design the antenna on laminates of any permittivity and the analyzes are complete with results in the frequency and time domains.
Resumo:
Department of Biotechnology, Cochin University of Science and Technology
Resumo:
This study was undertaken to isolate ligninase-producing white-rot fungi for use in the extraction of fibre from pineapple leaf agriwaste. Fifteen fungal strains were isolated from dead tree trunks and leaf litter. Ligninolytic enzymes (lignin peroxidase (LiP), manganese peroxidase (MnP), and laccase (Lac)), were produced by solid-state fermentation (SSF) using pineapple leaves as the substrate. Of the isolated strains, the one showing maximum production of ligninolytic enzymes was identified to be Ganoderma lucidum by 18S ribotyping. Single parameter optimization and response surface methodology of different process variables were carried out for enzyme production. Incubation period, agitation, and Tween-80 were identified to be the most significant variables through Plackett-Burman design. These variables were further optimized by Box-Behnken design. The overall maximum yield of ligninolytic enzymes was achieved by experimental analysis under these optimal conditions. Quantitative lignin analysis of pineapple leaves by Klason lignin method showed significant degradation of lignin by Ganoderma lucidum under SSF