Background: Vascular access (VA) is a prerequisite for initiation of hemodialysis (HD) in patients with end- stage renal disease (ESRD). Frequency and potency of V A types are varibus in different societies. We have done this study to achieve this goal. Materials and Methods: This descriptive retrospective study was performed over two months (august and September 2003) iq four HD centers in Isfahan, Iran. All of the patients who were treated with HD for more than 1 month were studied for the number, type of V A and some demographic factors. The questionnaires were completed at the patient"s bedside. Results: There were 320 patients. (199 male and 121 female). Mean age was 50.64± years. Among 412 permanent VAs which were created in the duration of HD, only 4 and 7 of them were graft and dual _ lumen cuffed catheters, respectively. All of the others were arterio venous fistula (AVF).The mean number of created permanent VAs in females was more than males. It was increased by some factors such as increasing the duration of HD, increasing the interval between creating permanent VA and initiation of HD. Although the latest was not statistically significant. 1 Year, 2-year, 3-year and 5- year SURVIVAL of AVF was 80%, 78%, 73% and 69%, respectively. Primary failure of AVF was. 13%. Conclusion: Regarding the statistics of other centers, SURVIVAL of AVF was low in Isfahan. The prevalence of grafts & dual - lumen cuffed catheters is lower than other countries. The majority of our patients use AVF as a VA. The earlier the patient is encouraged to create a permanent VA before initiation of HD, the AVF SURVIVAL is higher.

Metaheuristic algorithms have been increasingly used in different fields. The application of these algorithms for identifying and modelling natural phenomena such as flood and drought in terms of complexity and non-linear interactions can be considered as their capability in hydrology. In this paper, Symbiotic ORGANISM Search (SOS) algorithm was first introduced, then its application in tuning fuzzy expert system, aiming to find the region of influence area of hydrometric stations in the Southern Caspian Sea Basin. This basin has regularly experienced flood events, causing human loss and properties damages every year. The outcome of this research is used to estimate floods, and subsequently, to design flood control structures. A total of 61 hydrometric stations were selected in the study area and their physical, climatic and hydrologic characteristics including area, perimeter, minimum elevation, maximum elevation, mean slope, stream length, slope of main stream, equivalent rectangle length, equivalent rectangle width, form factor, shape coefficient, Gravelious factor, round coefficient, and mean annual precipitation were determined. Results indicated that out of 16 parameters, area, mean elevation, form factor, Gravelious factor, and mean annual rainfall, were the most significant parameters in relation to flood by employing the SOS. These variables were used as the input variables into the fuzzy system and SOS algorithm to tune the fuzzy system. Finally, the efficiency of the SOS algorithm was evaluated using the linear torque heterogeneity statistic. Therefore, 61 influence areas were determined that show homogenous areas in 61 watersheds. Results indicated the performance of SOS in determining region of influence of the sub-basins in the study area. In addition, the geographical vicinity is not a suitable criterion for finding homogenous areas.

Introduction: Aspiration pneumonia due to aerobic ORGANISMs is more common in the patients of severe head trauma, and is a major cause of mortality and morbidity in ICU patients.This is a survey of causative ORGANISMs and management of aspiration pneumonia in severe head injury. patients in ICU services of Rasht Poursina hospital, since march 1999 up to march 2000.Materials & Methods: In a cross-sectional study of 59 patients suffering from post -trnmatic aspiration pneumonia was carried out in ICU services of Rasht Poursina hospital since 1999 upto march 2000.Results: Klebsiella (37.29%) and pseudomonas (23.73%) were the most and enterobacter (6.78%) was the less common ORGANISMs. The most antibacterial drngs were Amikacin, 90% efficacy for klebsiella and 78.75% for pseudomonas and ciprofloxacin 100% efficacy for klebsilla and 70% for pseudomonas. Discussion: In the case of aspiration pneumonia due to gram negative ORGANISMs specially klebsiella and pseudomonas. The base of the treatment must be conducted with amikacin and ciprofloxacin and then continued with suitable antibacterial agents based on antibiogram.