Journal of School of Public Health and

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Background and aim: In this study the cytotoxicity to human epithelial lung cells of single-walled carbon nanotubes, multi-walled carbon nanotubes and chrysotile was compared based on the following cytotoxicity indices: no observable adverse effect concentration (NOAEC), inhibitory concentration 50 (IC50), and Total Lethal Concentration (TLC).

Materials and Methods: Human epithelial lung cells were exposed to different concentrations (1 to 1500 µg/ml) of carbon nanotubes and chrysotile for 6 and 24 hours. Cytotoxicity was assessed using the MTT assay. NOAEC, IC50, and TLC idices were determined by probit analysis.

Results: The results showed statistically significant correlations (p<0.001) between cytoxicity and exposure concentration in the case of all the three compounds. The NOAEC and IC50 indices were lowest for the multi-walled carbon nanotubes, while the single-walled carbon nanotubes showed the lowest TLC index.

Conclusion: Cytotoxicity of multi-walled carbon nanotubes at low concentrations was higher than that of single-walled carbon nanotubes and chrysotile. This would mean that exposure to this compound occurs at low concentrations. Thus, cytotoxicity of multi-walled carbon nanotubes is a cause for concern. It can be concluded, then, that, like chrysotile fibers, crabon nanotubes are also considerably toxic to human epithelial lung cells.

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  Background and Aim: Measuring the hand's grip strength and comparing it with its normative data is a valid method for detecting intensity of the numerous damages of hand. In addition, co mparing grip strength of people in different regions can reveal hidden facts resulting from genetic and environmental factors . Therefore , the present study was carried out with the aim of comparing grip strengths and three types of pinch (tip, key and palmar) strengths of healthy people living in five Iranian cities and determining normative data of grip strengths of citizens of these cities.

  Materials and Methods: This was an applied cross-sectional study. The study population included 1008 healthy adults (526 males and 482 females) from the Fars (Persian) ethnic populations in five cities of Iran ( Mashhad, Isfahan, Shiraz , Kerman and Yazd ). The American Society of Hand Therapists (ASHT) recommendations were followed to establish normative data of grip and pinch strengths . Jamar dynamometer and Seahan pinch gauge were used to measure grip and pinch strengths. In addition, the effect of body mass index (BMI) and other anthropometric variables (hand length, height and weight) on grip strengths was assesed.

  Results: In the present study, no significant differences were found between grip and pinch strengths of adults in the five cities. From among the parameters studied , height and hand length had the most influence on the grip strengths .

  Conclusion: The findings of this study show that populations of any particlular ethnic group have similar grip strength despite living in different geographical areas. The normative data of grip strength obtained in this study are important for ergonomists helping them to optimize work programs and designing tools, as well as for therapists helping them to reach the goals of treatment, assessing the body response to medical treatment, and detecting good function of the upper extremities .

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Background and Aim: This study aimed gender variations about adolescents' health-related quality of life. Materials and Methods: A cross-sectional study was performed on four hundred students selected by a Stratified random sampling. Two-way analysis of variance was used for the analysis of total health-related quality of life scores among boys and girls in terms of demographic factors. Data analysis was conducted with software SPSS 18 and LISREL8.8 programs. Results: There were important differences in health-related quality of life total score between boys and girls in relevance rank of birth, level of education and BMI. Although, these differences weren't statistically significant (p>0.05), Girls’ reports were higher compared to boys except for the emotional functioning subscale. Conclusions: Teachers and parents should make great efforts for meet the requirements and difficulties of emotional and behavioral in adolescent girls. It is Necessary to execute coping mechanisms by the training consultants to minimize stress and anxiety for the mother to be.

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  Background and Aim: It is known that personal behavior influences one’s health. The present study was designed to investigate lifestyle of non-medical students of governmental and private (Azad) universities in Kashan, Iran and factors affecting it.

  Materials and Methods: A cross-sectional study was carried out on 520 non-medical students in Kashan, Iran, selected by convenience sampling, in academic year 2013-14. Data on demographic characteristics and health behaviors were collected using standard valid questionnaires, for the latter the questionnaire being the Pender’s Health Promoting Lifestyle Profile II (HPLP II). The data were analyzed using the Kolmogorov-Smirnov test, followed by t-test, and U Mann-Whitney test to compare the means of the two populations. 

  Results: The m ean age of the students was 21.75 ± 2.5 years. Their overall health-promoting lifestyle score was of 2.43 (SD = 0.38). This score, as well as scores for the subcategories ─ nutritional behavior, spiritual development, physical activity, health responsibility, and stress management ─ were lower for the subjects with an experience of stressful events. Further analysis of the data showed that t here were significant differences between boys and girls as regards physical activity (P = 0.000), between single and married students as regards nutritional status (P = 0.032), and between working and non-working students as regards spiritual development (P = 0.014).

  Conclusion: The findings indicate that experienced stressful events lay the ground for the adoption of risky behaviors in university students. Therefore, universities should design and implement programs aiming at improving lifestyle of the students and promoting their health.

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Background and Aim: Children are one of the most vulnerable groups in the population. Child abuse is a complex phenomenon with multiple causes. The purpose of this study was to do a confirmatory factor analysis of child abuse potential inventory among Ahvazi children in Ahvaz, Iran.

Materials and Methods: This was a descriptive-analytical study, including all Ahvazi primary school pupils aged 8-13 years in the academic year 2015-2016.

The sample size for confirmatory factor analysis was determined based on the number of questions per parameter.The variance was extracted on the basis of mean scores and

composite reliability for structural equation modeling was determined based on the first-order and second-order confirmatory factor analysisusing the LISREL software.

Results: Confirmatory factor analysis revealed a short form of the child abuse's original 3-actor structure, including the psychological, physical and neglect scales. The outcomes indicated that the firstorder model was a better fit for the data than the second.

Conclusion: It can be concluded that the Ahvazi version of the child abuse potential inventory questionnaire is acceptable from a psychometric point of view. We think it is essential to take into consideration the diversity of perspectives between parents and children in future research in this area.

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Background and Aim: Considering the lack of attention to the health promotion of adolescents due to their perception of being healthy in most countries of the world, we aimed to evaluate the predictors of adolescent health promoting lifestyle through path analysis based on IMB model.

Materials and Methods: This is a descriptive-analytic study on 400 high school students in Andimeshk city in two urban and rural areas. The sample size was obtained using the Cochran formula.They were selected by classified random sampling. In this study, demographic data, information about IMB model structures and student adherence to healthy lifestyle were collected in four areas nutrition, physical activity, stress control and responsibility. Correlation between total structures was analyzed using SPSS-23 software. Lisrel 8.5 software. Meanwhile, the relationships between variables were analyzed using Path analysis to fit and approve model fit model using LISREL8.8 software.

Results: All structures of IMB model had a Significant relationship with adolescent healthy lifestyle. Self-efficacy structure had the most predictive power. In general, self-efficacy variables, 75%, motivation 66%, and 50% knowledge had a positive and significant effect on behavior. This model was able to explain 71% of the variance in adolescent lifestyle behavior. Also, in this model, the level of self-efficacy variance (behavioral skills), 52%,, And motivation variance was explained 57%. Motivation and knowledge indirectly influenced the lifestyle behavior (behavior) by 55% and 50%, respectively.

Conclusion: The findings of this study showed that the IMB model has a good application for explaining and predicting the healthy lifestyle of adolescents. Accordingly, it is recommended that health planners apply the IMB model in order to promote adolescent lifestyle in this population.

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Background and Aims: Generalized Structural Equation Modeling (GSEM) is a family of statistical techniques utilized in the analysis of multivariate, categorical and ordinal data in order to measure latent variables and their connection with each other. The aim of this study is to consider the structure of data, and introducing GSEM to medical science researchers and presenting a practical example of in medical science researches.

Materials and Methods: An introduction to Structural Equation Modeling (SEM), along with its advantages and disadvantages was presented, and also GSEM and its all kind of forms was specified. An example to study hypertension risk factors in patients suffering from diabetes was carried out, which was a demonstration of using GSEM method for binary response variables. The data includes a random sample of 2716 people from Golestan province cohort studies.

Results: Age, body mass index, abdominal obesity, residence place, socioeconomic status, salt intake had direct effect on hypertension. Race, education, vitamin D and physical activity had direct and reverse effect on hypertension (p.value<0.05).

Discussion: Unlike SEM, the limitative hypothesis that our data should have a normal distribution do not needed in this model, also GSEM is powerful tool in the analysis of categorized data. Nevertheless this method cannot perform goodness of fit test, and adjustment and modification method of the model directly, and that they are some limitation in using this method.