The electronic and optical properties of pentagonal B2C (penta-B2C) monolayer are investigated by means of the first-principles calculations in the framework of the density functional theory. The cohesive energy consideration confirms the good stability of the B2C nanostructure in this phase. The electronic band structure reveals that the valence band maximum (VBM) is located at [Formula: see text]-point of the first Brillouin zone (BZ) whereas the conduction band minimum (CBM) is situated at the center of the BZ, resulting in an indirect energy bandgap of about 1.5 eV. Furthermore, a calculated low absorption and low reflection of the material in low energy ranges denote the transparency of the B2C monolayer in the investigated range for normal light incidence. The obtained results may find application in fabrication of future opto-electronic devices.

Background and Purpose: Self-medication is an important concern in every part of the world. The aim of this study was to estimate the prevalence and to investigate the associate factors of self-medication among adults in Gorgan, north of Iran.  Materials and Methods: This descriptive cross-sectional study was carried out among adults aged 12 years and above who were residents in Gorgan city. The participants were selected using the multi-stage cluster sampling method. SPSS Software and Pearson's chi-squared test were used for data analysis. Results: A total of 592 households with 2050 respondents were visited. The prevalence of self-medication was 67.9%. A larger number of females were self-medicating (71.3%) than males (63.5%). The majority of the respondents self-medicated because of the previous use experience (59.3%). The main indication for self-medication use was headache (60.8%).  Analgesics were the most commonly self-medicated by the respondents (83.9%). Also, 88.6% of the respondents prepared their drug from drugstores. Furthermore, there were significant differences between self-medication and demographics characteristics including gender, age group, marital status, occupation, education level and income (p<0.05). Conclusion: The prevalence of self-medication especially with analgesics is relatively high among adult city-dwellers in Gorgan. So, preventive measures, such as strengthening of the communities awareness on the side effects of self-medication practice and regulation of pharmacies are very important mechanisms to decrease the practice.

Objectives: Organophosphate (OP) pesticides inhibit both red blood cell (RBC) and plasma cholinesterases (ChEs). Oximes, especially pralidoxime (2-PAM), are widely used as antidotes to treat OP poisoning. In addition, N-acetylcysteine (NAC) is sometimes used as an adjuvant antidote. The current study aimed to assess the feasibility of using NAC as a single therapeutic agent for OP poisoning in comparison to in vitro 2-PAM. Methods: This study was carried out at the Razi Drug Research Center of Iran University of Medical Sciences, Tehran, Iran, between April and September 2014. A total of 22 healthy human subjects were recruited and 8 mL citrated blood samples were drawn from each subject. Dichlorvos-inhibited blood samples were separately exposed to low and high doses (final concentrations of 300 and 600 μmol.L-1 , respectively) of 2-PAM, NAC and cysteine. Plasma and RBCs were then separated by centrifugation and their ChE activity was measured using spectrophotometry. Results: Although cysteine-and not NAC-increased the ChE activity of both plasma and RBCs over those of dichlorvos, it did not increase them over those of a high dose of 2-PAM. Conclusion: These results suggest that the direct reactions of 2-PAM and cysteine with dichlorvos and the reactivation of phosphorylated ChEs occurr via an associative stepwise addition-elimination process. High therapeutic blood concentrations of cysteine are needed for the elevation of ChE activity in plasma and RBCs; however, both this agent and NAC may still be effective in the reactivation of plasma and RBC ChEs.

Background & objectives:Drug abuse is one of the most psychosocial and public health challenges in the world that is increasing every day and lead to disability and death. The aim of this study was to investigate the epidemiology of death due to drug abuse in Golestan province. Methods: This cross-sectional study was carried out on all referential bodies to Golestan department of forensic medicine that were died due to drug abuse from March 2010 to March 2016. Data were collected from medical records and analyzed using SPSS version 16 and Pearson chi-square test. Results: Of the 170 people, who had drug abuse, 95.9% were male and 32.4% were 30-39 years old. The majority of cases (81.8%) were urban residents. Most of them were married (53.5%) and 38.2% of them had secondary education. Drug abuse was identified as the main cause of death (40%). In 56.5% of cases, injection was the most important way of drug abuse. Conclusion: Opium was the most common agents of death due to drug abuse in Golestan province that were observed mostly among married men aged 30-39 years. ‫ﻣ‬ ‫ﻣﺼﺮف‬ ‫ﺳﻮء‬ ‫از‬ ‫ﻧﺎﺷﯽ‬ ‫ﻓﻮت‬ ‫اﭘﯿﺪﻣﯿﻮﻟﻮژي‬‫ﮔﻠﺴﺘﺎن‬ ‫اﺳﺘﺎن‬ ‫در‬ ‫ﻣﺨﺪر‬ ‫ﻮاد‬ ‫ﺳﺎل‬ ‫در‬ ‫ﻫﺎي‬ 94 -1389 ‫ﺷﮑﺮزاده‬ ‫ﻣﺤﻤﺪ‬ 1 ‫زارﻋﯽ‬ ‫ﺣﺴﯿﻦ‬ ، 2 ‫ﺑﺎدﻟﯽ‬ ‫اﺑﻮاﻟﻘﺎﺳﻢ‬ ، 3 ‫ﺟﻠﯿﻠﯿﺎن‬ ‫ﺟﻌﻔﺮ‬ ، 4 ‫ﻃﻠﺐ‬ ‫ﻓﻼح‬ ‫اﺑﺮاﻫﯿﻤﯽ‬ ‫ﻓﺮاﻣﺮز‬ ، 5 ، ‫ﻟﺸﮑﺮﺑﻠﻮﮐﯽ‬ ‫ﻏﻼﻣﻌﻠﯽ‬ 6 ‫اﺳﻤﻌﯿﻠﯽ‬ ‫ﻣﻄﻬﺮه‬ ، 7

Background: Anxiety disorders are among the most common types of psychological disorders in the world. Anxiety is an inseparable part of every person's life and it seems that it is experienced more severely by university students. The present study aimed to investigate the prevalence of anxiety and its related factors among environmental and occupational health students. Materials and Methods: In this descriptive cross-sectional study in 2015, the participants were selected through census-based sampling; all the Bachelor students (continuous and discontinuous) of environmental and occupational health (141 respondents) from Qazvin University of Medical Sciences, Iran, participated in this research. Data were collected using a demographic questionnaire and Spielberger State-Trait Anxiety Inventory measuring respondents' level of anxiety. The collected data were analyzed by independent samples t-test, analysis of variance, and Pearson correlation in SPSS software. Results: The prevalence rates of state and trait anxiety in the sample were 29.1% and 20.6%, respectively. Furthermore, 29.1% of students of environmental health and 57.9% of students of occupational health suffered from moderate to high levels of anxiety. The greatest prevalence of trait anxiety among students of environmental and occupational health was recorded for below moderate anxiety with indices of 72.8% and 84.2%, respectively. On the other hand, no significant relationship was observed between students' year of study (ranging from the first to the fourth year) and state/trait anxiety. However, the results of Pearson correlation showed that there was a significant negative relationship between students' grade point average and trait anxiety. Conclusions: Anxiety among university students of environmental and occupational health range from moderate to high. Some measures should be taken to reduce this level of anxiety.

Background: Self-medication is an important concern for health authorities throughout the world. The women of reproductive ages were the most vulnerable groups at risk for self-medication in the society. The purpose of this study was to determine the frequency and some associated factors of self-medication in women of reproductive ages in Gorgan, north of Iran. Methods: This cross-sectional study was carried out on 800 women of reproductive age (15-49 years) who were residents in Gorgan, in 2018-2019. Data were collected through home visits and interviews using a checklist with 19 questions. Data were analyzed in SPSS-16 using Pearson's chi-squared test. Results: Self-medication was reported in 68.9% of reproductive ages. The majority of the self-medication was in the age range of 40-49 years (78.5%). The main cause for self-medication was found to be headache (68.6%) and common cold (57.7%). Most frequently, self-medication was related to pain killer drugs (90.6%) and NSAIDs (64.4%). Also, the major causes of selfmedication were found to be the previous use experience (n=307) and availability of drugs at home (n=266). Finally, we found a significant association between self-medication with age, marital status, occupation, education, income, number of children and family size (p<0.05). Conclusion: Self-medication, mainly in pain-killer drugs and NSAIDs were high among women of reproductive age in Gorgan. Therefore, it seems necessary to provide public trainings for all women of reproductive age and train them about the dangers and side effects of self-medication.

Background and objectives: Benzodiazepine poisoning is one of the most important and common medical emergencies worldwide. The purpose of this study was to evaluate the pattern of poisoning with benzodiazepines in Gorgan, Iran. Methods: This cross-sectional and descriptive-analytical study was conducted on patients with acute benzodiazepine poisoning admitted to 5 th Azar Hospital in Gorgan between 2008 and 2014. Data were collected from medical records of patients. Statistical analysis was performed using SPSS software (version 16). Results: Benzodiazepine poisoning accounted for 37.2% of all drug poisoning cases. Of the 230 cases of benzodiazepine poisoning, 108 (50.7%) were female, and most cases (53.5%) belonged to the 20-29 years age group. Suicide attempt was the predominant (91.1%) type of benzodiazepine poisoning. Among the benzodiazepines, alprazolam (33.3%) and diazepam (30.5%) were the chief causes of drug poisoning. In addition, in 7.5% of the subjects, benzodiazepines were taken in combination with other drugs, especially tramadol (19.2%). Age, marital status, employment status, education level and place of residence were significantly associated with benzodiazepine poisoning (P<0.001). Conclusion: Benzodiazepines, particularly alprazolam and diazepam, are responsible for more than one-third of all drug poisoning incidents in Gorgan. Self-poisoning with this group of drugs as an attempt to commit suicide is most prevalent among young individuals.