purpose: this study aimed to evaluate risk factors associated with threshold retinopathy of prematurity (rop) in premature infants referred to farabi eye hospital during 2008-2009. since blindness and sever visual impairments will occur in a high percentage of infants stricken with threshold retinopathy, we intended to examine relationship between demographic factors and threshold retinopathy i...

The first and second Zagreb indices of a graph are equal, respectively, to the sum of squares of the vertex degrees, and the sum of the products of the degrees of pairs of adjacent vertices. We now consider analogous graph invariants, based on the second degrees of vertices (number of their second neighbors), called leap Zagreb indices. A number of their basic properties is established.

background: chemical contaminants present in the work environments include gases, vapors, and solid and liquid suspended particles. the number of factories producing chemicals has increased significantly. each year, new products are introduced into the market. consequently, the number of employees at risk of exposure to these materials is increased. hazardous chemicals are used in the petrochem...

In this study, concentrations of heavy metals in soils around a Zn-smelter in Qeshm island, Iran, are investigated. Calculated geoaccumulation index (Igeo), contamination factor (Cf), and contamination degree (Cdeg) values indicate surface soil contamination by toxic metals (As, Cd, Pb, and Zn). The results also indicate that most contaminated areas are located in the vicinity of the smelter an...

objective: schizophrenia and other psychoses have devastating personal and social impacts and many efforts have been devoted to study ‎prodromal syndromes for psychosis in order to achieve earlier detection and interventions. however, only few studies have been ‎performed in developing countries on this subject, and there is a dearth of evidence in the iranian population. in this study, we ‎foc...

Risk assessment provides the possibility of planning and management to prevent and reduce the risk of desertification. The present study is aimed to assess the hazard and risk of desertification and to develop management programs in the semi-arid western regions of Golestan Province in Iran. Desertification rate was obtained using the Iranian model of desertification potential assessment. Since...

conclusions our results showed that the study population perceived a high likelihood of cchf risk. improving public knowledge and awareness could result in a more realistic assessment of cchf risk, hence better compliance with taking precaution measures to tackle the disease. results approximately 70% of the respondents reported the cchf risk to be 'high'. factors independently associated with ...