نسرین اسدی

Microperforated panels (MPPs), often considered as potential replacements for fiber absorbers, have a significant limitation in their absorption bandwidth, particularly around the natural frequency. This study aims to address this challenge by focusing on the optimization and modeling of sound absorption in a manufactured MPP.

The study employed Response Surface Methodology (RSM) with a Central Composite Design (CCD) approach using Design Expert software to determine the average normal absorption coefficient within the frequency range of 125 to 2500 Hz. Numerical simulations using the Finite Element Method (FEM) were conducted to validate the RSM findings. An MPP absorber was then designed, manufactured, and evaluated for its normal absorption coefficient using an impedance tube. Additionally, a theoretical Equivalent Circuit Model (ECM) was utilized to predict the normal absorption coefficient for the manufactured MPP.

The optimization process revealed that setting the hole diameter to 0.3 mm, the percentage of perforation to 2.5%, and the air cavity depth behind the panel to 25 mm resulted in maximum absorption within the specified frequency range. Under these optimized conditions, the average absorption coefficient closely aligned with the predictions generated by RSM across numerical, theoretical, and laboratory assessments, demonstrating a 13.8% improvement compared to non-optimized MPPs.

This study demonstrates the effectiveness of using RSM to optimize the parameters affecting MPP performance. The substantial correlation between the FEM numerical model, ECM theory model, and impedance tube results positions these models as both cost-effective and reliable alternatives to conventional laboratory methods. The consistency of these models with the experimental outcomes validates their potential for practical applications.

The occupational environment, the type of work overload or underload, physical risks, how individuals adapt to the workplace, and face the family - work constitute the sources of stress or occupational distress. Job stress emerges as the duties and tasks assigned to people are more than their abilities. This condition affects the health of individuals (physical and mental) and the type of employee relationships with their jobs and organization. This study aimed to investigate the relationship between stress management training and work ethics of employees.

This study aimed to investigate the relationship between stress management training and work ethics of employees. This research was an applied study in terms of purpose, a mixed exploratory (qualitative and quantitative) study in terms of data, a content  analysis (qualitative stage) and  cross-sectional survey (quantitative stage) in term of conduct. The study population in the qualitative section comprised experts (Experts in Psychology, Educational Management, and Social Medicine) according to the inclusion and exclusion criteria. In the qualitative section, the study population included experts and managers who had received stress management training. Sample size and sampling method in qualitative part was based on the principle of theoretical saturation, resulting in 12 people using purposive sampling method. In the quantitative part, the sampling was based on the Cochran’s formula, resulting in 220 people who were selected using cluster sampling method. To collect data in the qualitative section, we used semi-structured interviews and a researcher-made questionnaire on stress management training. In the quantitative part, we used the standard professional work ethics questionnaire of Armito et al. (2011). In the qualitative section, we used the content analysis of the interviews to analyze the data. In this regard, we used the coding method (open, axial, and selective coding), confirmatory factor analysis, exploratory factor analysis and structural equations. Then, we employed multivariate regression analysis to determine the relationship between the coping styles with stress and work ethics. The results showed that to deal with stressful situations, three basic strategies of event-focused coping, anxiety-focused coping, and avoidance-focused coping strategies can be used for stress management training models. Overall, the components presented for coping with stressful conditions have the necessary and appropriate validities. All three main coping strategies (event-focused, anxiety-focused, and refusal-focused) are suitable for explaining and fitting. So, they all are reliable and confirmed in the current research questionnaire of coping with stress. 

This barcode research was presented to the Ethics Committee and registered in the system (IR.IAU.TNB.REC.1400.121). 

Because the research is of mixed type (qualitative and quantitative), data analysis consists of two parts: qualitative data analysis and quantitative data analysis. The qualitative data analysis was preformed using conventional exploratory content analysis in three stages of open coding, axial coding, and selective coding. The quantitative data analysis, the appropriate statistical tests were used to examine and evaluate the research questions. At first, factor analysis technique was used to determine the status of the basic components of research and to assess their validity. Then, the relationship between research variables was examined using multivariate regression analysis technique.

Strategies for coping with stressful situations have a different effect on people’s professional work ethics so that the event-focused coping strategy has a significant positive relationship with professional ethics. The effect of event-focused coping strategy on professional work ethics is incremental. On the other hand, the anxiety-focused and avoidance-focused coping strategies have negative and decreasing relationship with professional ethics. The more emphasis on the event-focused coping strategy, the more would be the professional ethics of individuals and the more emphasis on the anxiety-focused and avoidance-focused coping strategies, the less would be the professional ethics of individuals.

This also affects health (physical and mental) of individuals and impacts the type of relations between personnel and their job and organization. Aim of this research is to present the stress management training model and its relationship with self-efficacy of employees. Population of the research includes managers and employees of governmental organizations in 2020. In this research, purposeful sampling of 220 subjects as the sample size was used. For qualitative study, purposeful sampling method was used and the inclusion criteria included the specialists and experts with minimum 5 years of experience who have passed the stress management training course. Measurement instruments in this study were two standard and normalized questionnaires i.e. Coping Inventory for Stressful Situations (CISS) developed by Endler & Parker(1990) and Generalized self-efficacy scale of Schwarzer, & Jerusalem(1992). After collecting the research data, the obtained information and results were analyzed using the descriptive data (mean and standard deviation) and inferential statistics (regression analysis). The results show that the coping strategies for stressful conditions have different effect on self-efficacy of individuals so that there is a significant positive association between problem- focused coping strategy and self efficacy and effect of the problem- focused coping strategy on self-efficacy is incremental(p<0.05). In other words, the more emphasis on the problem- focused coping strategy, the more the self-efficacy of individuals. On the contrary, there is negative and decreasing association between emotion –focused coping and avoidance coping strategies and self-efficacy (p<0.05). In other words, the more emphasis on the emotion- focused and avoidance coping strategies, the less the self-efficacy of individuals.

Today, cancer is one of the health concerns in modern societies. Cervical cancer occurs when abnormal cells grow in the cervix. Cervical cancer is one of the fatal cancers in women. Computational models are suitable for simulating complex phenomena such as cancer. Studying cervical cancer through computer modeling and simulation is an effective way to investigate and predict tumor behavior and patients’ response to treatment methods. The objective of this study was to develop a model to simulate the growth and treatment of cervical cancer and study it and analyze the process of chemotherapy in different stages of cervical cancer.

In this research, library study and NetLogo software tool were used for modeling and simulation. First, the anatomy of the uterus, cervix, fallopian tubes, vagina, lymph nodes of the uterus, liver, and lungs was designed and modeled. Then, different stages of cervical cancer were modeled according to TNM system and based on the way the cancer cells spread, tumor growth and spread were simulated and investigated in each stage. The control of tumor by chemotherapy mechanism was also modeled.

The model developed in this study provided the possibility of observing and investigating the growth and spread of tumor in different stages of cervical cancer. Predicting how the cervical tumor grows and behaves is one of the capabilities of the developed model.

This model can be used as an appropriate tool to understand different stages of cervical cancer.

Naturaly; Inhibin-A plays an important role in the reproduction, and its abnormal level can be associated with the risk of adverse pregnancy outcomes. The aim of the current study was to evaluate the effect of high level serum Inhibin-A in the first and second pregnancy trimesters on adverse pregnancy outcomes doing a systematic review and meta-analysis.

In a systematic search done in Pubmed, Embase, Magiran, Irandoc, Web of Science, Scopus, and Google Scholar in Persian and English languages since year 2000, seven articles were extracted and entered in the meta-analysis. Finally, odds ratio and confidence intervale were reported.

The current meta-analysis showed that high level of Inhibin-A incresed the odds of preclampsia (OR= 9.77, 95% C.I: 3.88-24.62); however, it did not affect on cesarean section delivery (OR= 1.06, 95% C.I: 0.80-1.41). As adverse pregnancy outcomes addressing  the fetus and new born, high level of serum inhibin A incresed the odds of low birth weight (OR=7.34, 95% C.I: 4.4-12.23), preterm birth (OR=5.18, 95% C.I: 1.89-14.17), and fetal growth retardation (OR=2.77, 95% C.I: 1.78-4.30).

High level serum Inhibin-A in the first and second pregnancy trimesters increases the odds of preeclampsia, preterm birth, fetal growth retardation, and low birth weight; however, it does not effect on cesarean section.

Proper assessment of the employees’ ability to work from an economic point of view is important for employers since it is one of the ways to increase human resource productivity. The purpose of this study was to investigate the relationship between job stress and ability to work in nurses of hospitals affiliated to Ahwaz University of Medical Sciences.

The present study was analytic and cross-sectional. The participants were 250 nurses with at least one year of work experience selected from all 8 hospitals affiliated to Ahwaz University of Medical Sciences using proportional sampling method. The dimensions of job stress and work ability were measured through the JCQ and WAI Questionnaires. For data analysis, descriptive statistics, Mann-Whitney U, Spearman correlation coefficient , and Kruskal-Wallis were used by SPSS20.   

 Work ability had a significant and direct correlation with and the decision making authority ( r= 0.161, p-value = 0.011) and physical isometric load (r= 0.136, p-value = 0.032). In contrast, a significant and inverse relationship was found between job ability and psychological needs (r=-0.177, p-value =0.005). No significant difference was observed between the ability to work and other dimensions of occupational stres.

In most nurses, moderate to high levels of job stress and moderate levels of  job ability were observed. To reduce their job stress and increase their ability to work, free decision making and social support should be increased, physical and psychological stresses should be adjusted, and job security should be enhanced.

Sleeping is an essential part of living and poor quality sleep can lead to a variety of physical and mental disorders. On the other hand, job stress is one of the main effective factors in reducing productivity in organizations and causing physical and mental complications in personnel. The aim of this study was to determine the job stress and its association with sleep quality among employees of Bid Boland Gas Refinery, Behbahan, Iran.  

In this descriptive study, 180 employees of Behbahan Bid Boland Gas Refinery participated in 2017. The data were collected using the Osipow occupational stress questionnaire and Pittsburgh sleep quality index questionnaire. To analyze the data, descriptive statistics, independent samples t-test, one-way ANOVA, Pearson's correlation coefficient and multiple linear regression analysis were used.

The results of the study showed that the mean and standard deviation of job stress and sleep quality perceived by employees were 167.27±19.66 and 10.72±2.22, respectively. Furthermore, there was a positive significant correlation between these two indexes (p<0.001). The regression model demonstrated that sleep quality was significantly associated with "role insufficiency" ( =0.499, p<0.001) and "role boundary" ( =0.197, p=0.035), the dimensions of Osipow job stress questionnaire. The model coefficient of determination indicated that 30.6% of sleep quality index changes are specified by variables of role insufficiency and role boundary.

The results showed that there was a significant correlation between job stress and sleep quality. Therefore, it is recommended to the gas refinery authorities to design and perform some plans for reducing job stress and sleep quality problems.

This research was funded by Behbahan Faculty of Medical Sciences. Conflict of interest: None declared.

 The Ethics Committee of Behbahan Faculty of Medical Sciences approved the study. (IR.BHN.REC.1395.18) How to cite this article: Asadi N, Hosseini SS. Study of Job Stress and Its Association with Sleep Quality Among Employees of Behbahan Bid Boland Gas Refinery in 2017: A Descriptive Study. J Rafsanjan Univ Med Sci 2019; 18 (8): 797-810. [Farsi]

Preterm labor and birth are associated with several neonatal complications including respiratory distress syndrome and intraventricular hemorrhage. Differentiating true and false labor pain is a dilemma to obstetricians.

To elucidate the role of cervical length measurement in prediction of birth in pregnant women with threatened preterm labor.

In this double blind randomized clinical trial, 120 women with gestational age

This RCT showed in case group, 78.9% of patient with cervical length

“Our results indicate that in women who presented preterm labor symptoms, cervical length measurement will result in decreased unnecessary tocolytic treatment. Women with cervical length ≥15mm should not receive tocolysis, however, withholding corticosteroid therapy in these patients needs further evidence.