41 research outputs found
Determination of the antioxidant properties of ethanol and water extracts from different parts of Teucrium parviflorum Schreber
This study was designed to examine in vitro antioxidant of extracts of Teucrium parviflorum Schreber. The plants were extracted successively in ethanol and water using soxhlet-apparatus. They were screened for possible antioxidant activity using the ABTS• (2,2'-azino-bis-(3-ethylbenzothiazoline-6- sulphonic acid)) radical scavenging capacity, DPPH• (2,2-diphenyl-1-picrylhydrazyl) radical scavenging capacity, superoxide anion radical scavenging capacity, hydrogen peroxide scavenging capacity, reducing power and metal chelating activities. These various antioxidant activities were compared with standard antioxidants such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and α- tocopherol. The extracts of T. parviflorum showed strong antioxidant activity and effective antioxidant assay. This antioxidant property depends on concentration and increase with increased amount of sample. In addition, total phenolic compounds in the extracts of T. parviflorum were determined as pyrocatecol equivalents. The results obtained in the present study indicated that T. parviflorum is a potential source of natural antioxidant.Keywords: Teucrium parviflorum, antioxidant activity, medicinal plants, extract, flower, leaves
Improved Jacobi matrix method for the numerical solution of Fredholm integro-differential-difference equations
This study is aimed to develop a new matrix method, which is used an alternative numerical method to the other method for the high-order linear Fredholm integro-differential-difference equation with variable coefficients. This matrix method is based on orthogonal Jacobi polynomials and using collocation points. The improved Jacobi polynomial solution is obtained by summing up the basic Jacobi polynomial solution and the error estimation function. By comparing the results, it is shown that the improved Jacobi polynomial solution gives better results than the direct Jacobi polynomial solution, and also, than some other known methods. The advantage of this method is that Jacobi polynomials comprise all of the Legendre, Chebyshev, and Gegenbauer polynomials and, therefore, is the comprehensive polynomial solution techniqu
Orthoexponential polynomial solutions of delay pantograph differential equations with residual error estimation
In this paper, a new matrix method based on orthogonal exponential (orthoexponential) polynomials and collocation points is proposed to solve the high-order linear delay differential equations with linear functional arguments under the mixed conditions. The convenience is that orthoexponential polynomials have shown to be effective in approximating a given function, fast and efficiently. An error analysis technique based on residual function is developed and applied to four problems to demonstrate the validity and applicability of the proposed method. It is confirmed that the present method yields quite acceptable results and the accuracy of the solution can significantly be increased by error correction and residual function. (C) 2015 Elsevier Inc. All rights reserved
Linalool improve biochemical damage and fatty acids composition of testes on fasting male rats
The aim of this study was to evaluate fatty acids compositions, oxidative stress levels and some antioksidant levels in the testes of 24 h fasted rats and linalool application. Adult male Wistar albino rats were assigned as Control (C), 24 h fasted (24 h F) group and added linalool (120 mg kg-1) during 24 h fasted (24 h F+L) groups. After applications, the animals were killed and the testes were excised for determination of tissue malondialdehyde, Glutation Peroxidase (GSH-Px), the activity of superoxide dismutase and determination of tissue fatty acids compositions. The activites of Superoxide Dismutase (SOD), Glutathione peroxidase (GSH-Px) and the level of Malondialdehyde (MDA) in testicular tissue specimens were determined spectrophotometrically. The fatty acid compositons in the testes were analyzed as percent by gas chromatography (GC). Researchers calculated between C 16:0 (palmitic acid) andC22:6 (docosahexaenoic acid) fatty acids in the testes of all experimental groups. Treatment with fasted rats resulted in a significant reduction inC16:l (palmitoleate) fatty acids when compared to the control rats (p<0.05). C16:l fatty acids were higher in linalool application than fasted groups (p<0.05). C22:4 (docosatetraenoic Acid), C22:5 (docosapentaenoic acid), C22:6 n3 (docosahexaenoic acid) fatty acids were lower in the fasted group than the control group. In addition, C22:4, C22:5, C22:6 fatty acids compositions in the linalool treatment group were higher than the fasted group (p<0.05). Saturated fatty acids levels in all experiment groups were not change as statistically (p>0.05). SOD and GSH-Px levels in the fasted rats were statistically lower than control groups (p<0.05). Both SOD and GSH-Px levels in the linalool application groups were not statistically a change compared to fasted groups (p>0.05). In addition, MDA levels in the fasted groups were higher than control groups. Besides, MDA levels in the linalool application groups were lower compared to fasted groups (p<0.05). These findings indicate that fasted state has oxidative effects on testicular tissue and linalool has protective effects on male reproductive system. © Medwell Journals, 2011
Solution of the delayed single degree of freedom system equation by exponential matrix method
In this paper, an exponential collocation method for the solution linear delay differential equations with constant delay is presented. The utility of this matrix based method is that it is very systematic and by writing a Maple program, any type of second order linear differential delay equation can be solved easily. The method is applied to three different types of delay equations; linear oscillator with delay (i) in the restoring force term, (ii) in the damping term, and (iii) in the acceleration term. Time response curves have been plotted for each type and the effect of the parameters of the delay terms has been shown. An error analysis based on residual function is carried out to show the accuracy of the results. (C) 2014 Elsevier Inc. All rights reserved
Porous Silicon Based Sensor for Organic Vapors
Porous silicon (PS) has been an attractive material for enhancing optical properties of silicon. Its large surface area for sensor applications and compatibility with silicon-based technologies has been a driving force for further technology development. In this study, ability of PS to sense at room temperature organic vapors such as acetone, trichloroethylene and hexane, which are harmful to human health, has been investigated. Electrical (DC) and photo-luminescence (PL) measurements in a controlled atmosphere (nitrogen gas and an organic vapor mix) were performed to test the sensor response towards the organic vapors. It was found that PS surface is very sensitive against these vapors. The experimental results also suggested that PS can be used as a new electro-optical material to sense harmful vapors
Morphometric evaluation and surgical implications of the infraorbital groove, canal and foramen on cone-beam computed tomography and a review of literature
Background: The purpose of this study is to evaluate the anatomy, morphometry, and variations of infraorbital groove (lOG), infraorbital canal (IOC) and infraorbital foramen (IOF) on the cone-beam computed tomography (CBCT) images and to investigate their relations with surrounding structures
The determination of sodium salicylate effect to body weights and fatty acid values in the frontal lobe of brain on the immobilized rats
WOS: 000340586900064
An analysis of the aetiology, prevalence and clinical features of dentine hypersensitivity in a general dental population
Hamidi, Mehmet Mustafa/0000-0003-3461-7925; Colak, Hakan/0000-0001-8262-0913WOS: 000307486400016PubMed: 22913162AIM, Dentine hypersensitivity may be defined as pain arising from exposed dentine typically in response to chemical, thermal or osmotic stimuli that cannot be explained as a rising from any other form of dental defect or pathology. The aim to this cross-sectional study was to determine prevalence of dentine hypersensitivity (DH) and to examine some associated etiological factors in a study of patients visiting general dental practitioners in Turkey. PATIENTS AND METHODS, A total of 1368 patients were examined for the presence of cervical dentine hypersensitivity by means of a questionnaire and intraoral tests by (air and probe stimuli). The patients have at least two different quadrants which have sensitive teeth with sound exposed cervical dentin on the facial surface were included the study. RESULTS, A total of 285 teeth were diagnosed as having dentine hypersensitivity in 73 patients, giving an overall prevalence figure for dentine hypersensitivity of 5.3%. 40-49 years age group was the cohort with the greatest number of subjects with DH and females had more predilection than males. Upper premolars were most affected and the commonest initiating factor was cold drinks. Subjects who smoked did not have more sensitive teeth on average than subjects who did not smoke (p > 0.05). Approximately half of the patients reported DH for a duration of within 1-3 days. The commonest etiological factor with the sensitive teeth was the gingival recession. CONCLUSIONS, The prevalence of dentine sensitivity in this sample was lower compared to studies carried out previously in different populations both general practice and hospital clinics. Further larger scale studies are required to assess its prevalence in Turkish population