Search published articles


Showing 24 results for Mar
Microplastics and Human Health: Perception of Risks and Consequences
Samaneh Dehghani, Masud Yunesian,
Volume 19, Issue 4 (3-2024)
Abstract
Microplastics refer to plastic particles and fragments smaller than 5 millimeters in various forms, derived from the breakdown of larger plastics or initially introduced into the environment from the primary constituent particles of plastic. The exact date of the emergence of microplastics in the environment is not precisely known, but it certainly predates the naming of these particles (2004). These particles can enter the bodies of living organisms, including humans, primarily through ingestion and inhalation. Their effects on the body depend on their size, chemical composition, and the composition of substances that later absorb these particles. In this article, we will first briefly examine the classification of these particles in terms of chemical composition and their origins, and then review some evidence of their presence in biological tissues and fluids. Given the increasing production and use of plastics in human life and the fact that most microplastics in nature derive from the breakdown of larger plastics, sometimes several years after their disposal, it is expected that even if plastic production decreases or stops, we will continue to see an increase in their presence in nature for years and decades, leading to human exposure to these compounds (whose effects and consequences of this exposure are not yet fully understood).

Epidemiology of Suicidal Ideation and Some Related Factors in Students of Gonabad University of Medical Sciences in 2023
Ali Alami, Hassan Eshaghiyan Farimani, Farnaz Sharifi Mood,
Volume 20, Issue 3 (12-2024)
Abstract
Background and Objectives: Suicide is a major health concern worldwide, and there is a strong association between the presence of suicidal ideation and suicide attempt in the future. This study aimed to determine the epidemiological status of suicidal thoughts among university students and its correlation with some of their personal, family, and social factors.
Methods: An analytic cross-sectional study was conducted on 556 students of Gonabad University of Medical Sciences (GMU) who met the inclusion criteria and were selected by multi-stage sampling in 2023. To collect data, a checklist and the Beck Scale for Suicidal Ideation (BSSI) were used. The collected data were analyzed using independent t-tests, chi-square, Fisher's exact test, and logistic regression.
Results: The prevalence (95% confidence interval) of suicide ideation among students of GMU was estimated at 20.5% (17.2-23.8%), with 11.5% of the students having high-risk (High and very high risk) suicidal thoughts. The prevalence of suicidal ideation was significantly higher among female compared to male students (P=0.016). Moreover, single students had more suicidal thoughts compared to married ones (P=0.019). In contrast, there was no statistically significant association between suicidal ideation and age, native status, place of residence and faculty of study of students.
Conclusion: The prevalence of suicide ideation and high-risk suicide ideation among the students was found to be relatively high. Thus, attention to state of mental health of students, especially female and single students, as well as creating suitable conditions for living and studying for them is recommended.

Determinants of Dental Care Utilization for Children Under Six: A Study Based on Andersen’s Behavioral Model
Fatemeh Gorji, Abolghasem Pourreza, Masud Yunesian, Simin Zahra Mohebi, Mahnaz Ashourkhani,
Volume 21, Issue 2 (9-2025)
Abstract
Background and Objectives: Timely use of dental services in early childhood plays an essential role in maintaining the health of primary teeth and preventing complications related to jaw development, nutrition, speech, and mental well-being. Regular dental visits help prevent early childhood caries and its consequences. This study aimed to evaluate factors influencing the use of dental services for primary teeth from parents’ perspectives, based on Andersen’s Behavioral Model.
Methods: This descriptive-analytical cross-sectional study was conducted in 2023 among 395 parents of children under six attending health centers in Semnan, Iran. Participants were selected using simple random sampling. Data were collected online via the Hackey questionnaire and analyzed using SPSS version 26 applying Chi-square tests and logistic regression.
Results: A minority of parents were aware of the appropriate timing for the first dental visit. Forty-five percent sought care only when problems occurred, while 36% attended regular check-ups. Overall, 62% reported moderate to good financial status, and 82% had basic insurance coverage. Key determinants of dental attendance included maternal education, service accessibility, insurance coverage, health information sources, and the characteristics of the healthcare providers as an educator. Larger family size and negative experiences with healthcare staff were associated with reduced utilization.
Conclusion: Interventions at individual and structural levels are needed to promote regular pediatric dental visits. Enhancing parental awareness, involving influential health personnel, expanding dental insurance, and fostering positive provider–parent interactions are recommended.

Missing Data in Medical Research: A Practical and Illustrated Review for Researchers and Students
Parisa Amjadi Zin Hajloo, Mohammad Heidari,
Volume 21, Issue 4 (3-2026)
Abstract
Missing data is a common and unavoidable challenge in medical and epidemiological research, often leading to biased estimates, reduced statistical power, and misleading interpretations when not properly addressed. Despite its importance, accessible and practical educational resources on this topic remain limited in Persian. This educational article provides a clear and structured overview of the fundamental concepts of missing data, including definitions, common patterns (univariate and multivariate), and the three major mechanisms of missingness: MCAR, MAR, and MNAR. A range of widely used approaches for handling missing data is summarized, from basic methods such as case deletion and simple imputation to more advanced techniques including multiple imputation and likelihood-based procedures (EM and MLE). Practical examples and visual illustrations are incorporated to facilitate conceptual understanding. The ultimate goal of this article is to provide a practical framework for researchers and students, enabling them to select the appropriate approach for dealing with missing data in the design and analysis of their research and to prevent analytical errors.

Page 2 from 2     

© 2026 , Tehran University of Medical Sciences, CC BY-NC 4.0

Designed & Developed by : Yektaweb