Comparison of the value of multidetector-row computed tomography in diagnosis of biliary obstruction reasons with the results obtained from invasive procedures

زمینه و هدف: تصویر برداری تشخیصی نقش اساسی در تشخیص غیر تهاجمی علل انسداد صفراوی و غربالگری بیماران با ریسک بالا را دارا می باشد. این مطالعه با هدف مقایسه ارزش سی تی اسکن مولتی اسلایس در تشخیص علل انسداد صفراوی با یافته های حاصل از روش های تهاجمی انجام شده است. روش بررسی: در این مطالعه توصیفی ـ تحلیلی به روش سرشماری، کلیه بیمارانی که از بهمن ماه 1388 تا خرداد ماه 1390، (50 بیمار)، دارای تشخیص انسداد صفراوی، بر مبنای یافته های کلینیکی و سونوگرافیک بودند، با روش سی تی اسکن مولتی اسلایس (MDCT) بررسی شدند و گزارش رادیولوژی آن ها با یافته های حاصل از سایر روش های تهاجمی شامل تکنیک کلانژیوگرافی معکوس از طریق آندوسکوپ (ERCP)،PTC (Percutaneous transhepatic cholangiography) و یا جراحی مورد مقایسه قرار گرفت. یافته ها: یافته ها نشان داد که حساسیت، ویژگی و دقت سی تی اسکن مولتی اسلایس در تشخیص علل بدخیم انسداد صفراوی به ترتیب 100، 4/88 و 94، در تشخیص علل خوش خیم انسداد صفراوی به ترتیب 75، 100 و 96، در تشخیص سنگ صفراوی به ترتیب 4/94، 100 و 98 بود و رابطه معنی داری بین شدت اتساع مجاری صفراوی و خوش خیم بودن یا بدخیم بودن عامل انسدادی وجود داشت (001/0>P). نتیجه گیری: بر مبنای یافته های این مطالعه، سی تی اسکن مولتی اسلایس روشی سریع ،غیر تهاجمی و با دقت بالا در تشخیص علل انسداد صفراوی و افتراق عوامل انسدادی خوش خیم از عوامل بدخیم بوده و برنامه ریزی قبل از عمل جراحی مفید می باشد

The estimation of investment risk in an asset portfolio by using value at risk method (VAR)

This study attempts to use value at risk method (VAR) as risk measurement criterion in formation of household asset portfolio. To do this, the data which are related to the assets price including: bank deposit, bonds, stock, exchange, coin, and housing that are used in time period of 1991 to 2011 and the value at risk of portfolio is calculated in reliability level of 90%, 95%, and 99% and in time periods of one year and 19 years. After calculating returns, return standard deviation, correlation coefficient among assets and VAR of every asset, the optimal mix of assets is extracted by using variance- mean model and Matlab software and assets portfolio risk is calculated by VAR method. The results indicated that there is the most portfolio risk of 55/13% with the probability of 99% for high risk people and the lowest portfolio risk of Zero%, with the probability of 90% for low risk people. In one year period, there is also the most portfolio risk of 17/51% with the probability of 99% for high risk people and the lowest portfolio risk of 88% with the probability of 90% for low risk people

The estimation of investment risk in an asset portfolio by using value at risk method (VAR)

This study attempts to use value at risk method (VAR) as risk measurement criterion in formation of household asset portfolio. To do this, the data which are related to the assets price including: bank deposit, bonds, stock, exchange, coin, and housing that are used in time period of 1991 to 2011 and the value at risk of portfolio is calculated in reliability level of 90%, 95%, and 99% and in time periods of one year and 19 years. After calculating returns, return standard deviation, correlation coefficient among assets and VAR of every asset, the optimal mix of assets is extracted by using variance- mean model and Matlab software and assets portfolio risk is calculated by VAR method. The results indicated that there is the most portfolio risk of 55/13% with the probability of 99% for high risk people and the lowest portfolio risk of Zero%, with the probability of 90% for low risk people. In one year period, there is also the most portfolio risk of 17/51% with the probability of 99% for high risk people and the lowest portfolio risk of 88% with the probability of 90% for low risk people

The estimation of investment risk in an asset portfolio by using value at risk method (VAR)

This study attempts to use value at risk method (VAR) as risk measurement criterion in formation of household asset portfolio. To do this, the data which are related to the assets price including: bank deposit, bonds, stock, exchange, coin, and housing that are used in time period of 1991 to 2011 and the value at risk of portfolio is calculated in reliability level of 90%, 95%, and 99% and in time periods of one year and 19 years. After calculating returns, return standard deviation, correlation coefficient among assets and VAR of every asset, the optimal mix of assets is extracted by using variance- mean model and Matlab software and assets portfolio risk is calculated by VAR method. The results indicated that there is the most portfolio risk of 55/13% with the probability of 99% for high risk people and the lowest portfolio risk of Zero%, with the probability of 90% for low risk people. In one year period, there is also the most portfolio risk of 17/51% with the probability of 99% for high risk people and the lowest portfolio risk of 88% with the probability of 90% for low risk people

Meritocracy, missed link in process of selecting successful managers

Abstract: This study aims to select talented students has been designed to teach management skills. In this study, the expression of some general information about management and its significance, as well as the ta sks, skills and management role using the theoretical foundations as well as various interviews carried out by experts of Sciences, factors in choosing a successful future managers of education were identified. After identifying these factors in order to analyze the data using analysis of variance test, 95% confidence level that have variables that are on average less than 5 points and Ann, wa s removed. As well as the factor analysis, a s well as to reduce the variables and their categories were used. For the purpose of ranking variables and the specified factors, Friedman te st were used. According to the results of an introduction to the basics of Islamic management, entrepreneurial skills, values accepted by the people, the power of decision, etc. Among the missing is that successful executives need to jump in and take into consideration education

Evaluation of the modified HTK solution in pancreas transplantationdAn experimental model

One of the great challenges in pancreas transplantation is the ischemia reperfusion injury. It is mentioned that free oxygen and/or nitrogen radicals play a prominent role in this phase. To minimize this problem, a modified histidineetryptophan eketoglutarate (HTK) solution that contains modified antioxidants has been developed. Our aim was to evaluate this solution in improving the viability of the pancreas in comparison with standard HTK and University of Wisconsin (UW) solutions in a porcine model of pancreas transplantation

An efficient method for a class of integro-differential equations with a weakly singular kernel

In this work, a class of volterra integro-differential equation with a weakly singular kernel is discussed. The shifted Legendre Tau method is introduced for finding the unknown function. The proposed method is based on expanding the approximate solution as the elements of a shifted Legendre polynomials. We reduce the problem to a set of algebraic equations by using operational matrices. Also the convergence analysis and error estimation have been discussed and approved with the exact solution. Finally, several numerical examples are given to demonstrate the high accuracy of the method.Publisher's Versio