Background Exposure to noise associated with injuries has become a public health issue in recent years. This study aimed to show the role of the acoustical structure of the ear canal on the typical occupational sound pressure levels at different frequencies. Methods This cross-sectional study was done on 20-30-year-old participants. White noise was used at 3 levels, including 75, 85, and 95 dB as the stimulus sound pressure levels (SSPLs). selleck The speakers had a 1.5-meter distance from the participants and at the height of 87 centimeters from the lab ground and were located in front of the participants. The SSPLs were measured outside (cavum part of the external ear) and inside the right ear of each participant. Measurements were done at the total sound pressure level and in the 1/1 octave frequencies. The duration for each measurement was 10 seconds. The independent sample t test was used for the statistical analysis, and the equality of means were rejected at p less then 0.05. Results There were 30 (50%) males out of the 60 participants. The mean ± SD for the age of all the participants was 23.29±2.93 years. The total sound pressure level difference between the inside and outside of the ears of male and female participants was statistically significant (p less then 0.001) at the stimulus sound pressure levels. The peak resonance was observed in the frequencies 2000 Hz and 8000 Hz for males and 8000 Hz for females. Conclusion The ear canal can amplify the sounds and increase the sound pressure levels. This amplification was found to be greater for males than for females.Background Self-determination skills enable to support an individual's needs and make decisions to function independently. Improvement of self-determination skills has had a positive result for adolescents at risk of Emotional and Behavioral Disorders (EBD). The aim of this study was to investigate the effect of occupational therapy interventions on the self-determination skills of adolescent girls at risk of emotional-behavioral disorders. Methods In this single-blind control trial study, 14-16-years-old girl students (n=54) at risk of EBD were recruited by cluster sampling from secondary high schools of Tehran, Iran. Youth self-report Questionnaire (YSR) was used to include adolescents at risk of EBD in the study and were randomized into the intervention (n=27) and control group (n=27) by block randomization. The Student Self-Determination Scale (SDSS) and the Self-determination Parent Perception Scale (SDPPS) were used to collect data. Students in the intervention group participated in 8 - once a week- sessions of occupational therapy and the control group received no training. Data were analyzed by repeated-measures analysis of variance (RMANOVA), Bonferroni test and SPSS 16.0 version. The significance level was set at 0.05. Results The score of self-determinations (SDSS) increased significantly in the intervention group after the intervention (p0.05); also, the score of parents' perception of student self-determination (SDPPS) increased but there were not significantly different (p=0.064). Conclusion The findings indicated self-determination skills could be taught to adolescents at risk of EBD in OT sessions. Since self-determination has been identified as the necessary skills for adolescents at-risk to transition into adulthood, occupational therapists have an important role in promoting self-determination skills in adolescents at risk of EBD.Background The overdose of illicit drugs is not always fatal but can lead to various complications. One of the unusual medical complications is a sensorineural hearing loss (SNHL). There are multiple case reports about this subject. Considering the importance of hearing loss on quality of life, we investigated hearing status in patients with overdose of illicit drugs. Methods This cross-sectional study was performed in Loghman Hakim hospital in Shahid Beheshti University of Medical Sciences, Tehran, Iran, in 2016-2017. The hearing status of 95 patients with illicit drugs overdose and 44 healthy individuals were assessed using standard pure tone audiometry and distortion product otoacoustic emissions. The patient group was categorized based on hearing status and compared based on some variables. We applied 2 independent t tests, Mann-Whitney, Chi-square, and binary logistic regression tests. All analyses were conducted in Stata 12 (STATA Corp, USA) and significance level was set at less than 0.05. Results We found higher percentage frequency of SNHL in the patient group than the control group (15.8% vs 2.3%; p=0.021). The frequency of hearing loss was 21.7% in opioid users, 5.3% in stimulant users, and 6.3% in concomitant use of both. There was a significant relationship between SNHL and overdose of illicit drugs (aOR = 14.48, 95% CI = 1.53-136.44; p=0.019) with adjusting age, sex, and smoking. Conclusion Illicit drugs overdose can potentially affect the hearing system. Opioid drugs, especially methadone and tramadol, have been found to affect the hearing system. Therefore, it is important to conduct longitudinal studies to demonstrate the role of opioid drugs on the hearing system.Background Injection of drugs is one of the most serious health problems among Iranian living with HIV/AIDS. The injection of drugs, accounting for the transmission of more than two-thirds of HIV infections. HIV remains a major concern around the world and is expected to be the third leading cause of mortality worldwide. Thus, the aim of this study was to explore the predictors of injection drug use in the elderly patients living with HIV/AIDS. Methods This was a cross-sectional study executed in Tehran City, Iran, in 2018. A total of 160 individuals aged 60 years and older with HIV from different counseling centers were selected by convenience sampling. Data were collected using questionnaires including a positive state of mind, coping, social support, and a checklist of demographical variables. Bivariate analysis and multiple logistic regression using SPSS software version 21.0 were employed to determine factors associated with drug injection. The statistical tests were performed with a significance level of 5% (p≥0.