ABSTRACT
Objective: Electrical low frequency stimulation [LFS] is a new therapeutic method that moderates hyperexcitability during epileptic states. Seizure occurrence is accompanied by some changes in action potential [AP] features. In this study, we investigated the inhibitory action of LFS on epileptiform activity [EA] induced-changes in AP features in hippocampal CA1 pyramidal neurons
Materials and Methods: In this experimental study, we induced EA in hippocampal slices by increasing the extracellular potassium [K+] concentration to 12 mM. LFS [1 Hz] was applied to the Schaffer collaterals at different pulse numbers [600 and 900] at the beginning of the EA. Changes in AP features recorded by whole-cell patch clamp recording were compared using phase plot analysis
Results: Induction of EA depolarized membrane potential, decreased peak amplitude, as well as the maximum rise and decay slopes of APs. Administration of 1 Hz LFS at the beginning of EA prevented the above mentioned changes in AP features. This suppressive effect of LFS depended on the LFS pulse number, such that application of 900 pulses of LFS had a stronger recovery effect on AP features that changed during EA compared to 600 pulses of LFS. The constructed phase plots of APs revealed that LFS at 900 pulses significantly decreased the changes in resting membrane potential [RMP], peak amplitude, and maximum rise and decay slopes that appeared during EA
Conclusion: Increasing the numbers of LFS pulses can magnify its inhibitory effects on EA-induced changes in AP features
ABSTRACT
Background: Genetic polymorphisms of drug metabolisms by cytochrome P450 [P450s] could affect drug response, attracting particular interest in the pharmacogenetics. Due to the importance of CYP2C19* 17 allele and its capability of super- fast metabolism and also lack of information about distribution of the alleles in Iranian population, this research aimed to use High Resolution Melting [HRM] method compared to PCR-RFLP for genotyping healthy Iranian population
Methods: Blood samples were collected from 100 healthy Iranian volunteers. DNA was extracted by salting out method. Real-time PCR was used for amplification of the CYP2C19 gene and the alleles were identified by HRM. Sequencing was used to confirm the amplified DNA fragments and data were analyzed using SPSS software ver.18
Results: The frequency of alleles CYP2C19*1/*1, CYP2C19*1/*17 and CYP2C19*17/*17 were estimated as 58.33, 29.1 and 11.1%, respectively. Specificity and sensitivity of HRM method were 90% and 100%, with respect to PCR-RFLP. Also, HRM analysis has been evaluated as a faster and more effective approach
Conclusion: Comparison of our results based on HRM analysis with PCR-RFLP showed that our developed method is rapid, accurate, fast and economic to study the CYP2C19*17 allele and it is appropriate for other similar population genetic studies
ABSTRACT
Objectives: ceramics have advantages such as optimal esthetics and biocompatibility. However, in the oral environment, they are subjected to high levels of stress due to masticatory forces, saliva, thermal changes and alterations of pH, which increase their risk of fracture. Since replacement of these restorations is costly and time-consuming, composite resin is often used for intraoral repair of these restorations. This study aimed to assess the shear bond strength of two porcelain repair systems by Pulpdent and Ultradent and evaluate the effect of number of silane layers on the shear bond strength
Methods: this invitro experimental study was conducted on 66 porcelain blocks measuring 3×5×8mm. In each kit, samples were randomly divided into three groups of 11. Silane was not used for group one. Groups two and three received one coat and two coats of silane, respectively. After surface preparation, composite was bonded to ceramic surfaces. Data were analyzed using two-way ANOVA
Results: the LSD test showed that application of Ultradent silane significantly affected the shear bond strength [P<0.05] while Pulpdent silane had no such effect [P=0.89]. Application of one layer and two layers of silane was not significantly different [P=0.94]
Conclusion: ultradent ceramic repair kit yields higher shear bond strength at the ceramic-composite interface compared to Pulp dent ceramic repair kit. Use of one or two layers of silane does not make any significant difference with regard to the shear bond strength of ceramic to composite
ABSTRACT
Introduction: Human resources development is one of the most important components of any organization and detecting important factors influencing human resources management plays an essential role in the success of the firms. In this study, we investigated different factors influencing human resources productivity of Shiraz University of Medical Sciences staff
Method: The present research was a cross-sectional study. Sample size was calculated 208 individuals. To access information about the human resource productivity, a valid and reliable questionnaire was used. The data were analyzed using SPSS software. Pearson correlation was used for statistical analysis of the data [p=0.05]
Results: The results showed that there was a statistically significant relationship [p-value<0.001] between human resources productivity and factors affecting the productivity of human resources [motivational factors, leadership style, creativity and innovation, general and applied education, and competitive spirit]. Motivational factors [r =0.89] and general education [r =0.65] had the most and the least effects on human resources productivity
Conclusion: Considering the fact that motivational factors were the most effective factors on human resource productivity, we recommend that managers should care more than before about this factor; also, in order to motivate the employees, they should consider the staff's individual differences
Subject(s)
Humans , Staff Development , Efficiency, Organizational , Cross-Sectional Studies , Surveys and QuestionnairesABSTRACT
Liposomes have attracted much attention as a novel drug delivery system for controlled and/or targeted release of drugs. In reverse-phase evaporation, which is a well-known method of preparation for LUVs and SPLVs, the phospholipid concentration affects the preparation process, as well as characteristics of the resulting liposomes. Drug release rate from liposomes depends on permeability of the liposomal membranes. Cholesterol [CH] is quite often included in liposomal membranes to reduce their permeability to water-soluble molecules. In this study, the required concentration of the phospholipid Ovotin' 160 [O160] for the preparation of urea-containing stable plurilamellar vesicles, and the effect of different percentages of cholesterol on the encapsulation parameters and release rate of urea as a water-soluble model drug were investigated. The results show that there is a critical concentration of the phospholipid, under which the capability for the formation of a stable emulsion [in the emulsification part of the preparation process] sharply decreases. The release rate and encapsulation parameters increased when the molar ratio of cholesterol to O160 was 5% and decreased with the ratios of 50% and 100%. Therefore, in preparation of the optimum samples a balance between the encapsulation parameters as well as the release pattern should be considered carefully