فهرست مطالب امیرحسین هاشمیان

Composite materials are of great interest due to their exceptional strength, hardness-to-density ratio, high corrosion resistance, and low weight. One of the suitable methods for making composite pipes is using the extrusion process. Extrusion is a plastic deformation process that due to the compressive state of stress in extrusion, materials with low plasticity can be formed by this method. This article deals with the experimental-numerical investigation of extrusion, from various methods of forming process. Extrusion is done on a composite tube using aluminum and magnesium alloys. Aluminum is used due to its strength compared to high weight, excellent malleability, and magnesium due to the lightest structural metal, the lowest density among structural materials, machining, welding and casting capabilities, as well as high specific strength. The mentioned process was tested at different extrusion ratio, temperature and speed, and the effect of different process parameters on the properties of the extruded product was investigated. Then the process was simulated in the software and the experimental results obtained from the laboratory work and the numerical results obtained from the simulation were compared and validated with each other and the error percentage between the graphs of the experimental and numerical results was examined.

Organizational commitment is a state in which a person considers the organization and especially its goals to be his representative and has the desire to remain a member of that organization. Clinical competence is the foundation of practical nursing work. This research was conducted with the aim of investigating the relationship between clinical competence and organizational commitment and related factors in nurses working in special departments of hospitals affiliated to Kermanshah University of Medical Sciences in 2017

In this correlational study, 227 nurses working in the special care departments of educational hospitals in Kermanshah were selected by available sampling method. The data collection tool included Allen and Mayer's questionnaire of nurses' clinical competence and organizational commitment, whose reliability and validity have been proven in various studies. Data were analyzed using SPSS version 22 software and at a significance level of P>0.05.

The average scores of organizational commitment and clinical competence in nurses were 119.9 ± 23.5 and 73.35 ± 2.18 respectively. No significant relationship was found between clinical competence and organizational commitment. The average score of clinical competence in nurses who had clinical work experience between 6-10 years was higher than others (P < 0.05).

In this study, clinical competence and organizational commitment of intensive care unit nurses were high, but no significant relationship was observed. Therefore, the health service system can increase their commitment by improving the clinical qualification of nurses or employing nurses with higher qualifications.

Background and

Cisplatin is one of the widely used chemotherapeutics, that directly affects the ovaries and uterus leading to infertility. This study aimed to investigate the effects of inositol and vitamin C on cisplatin-induced damage to ovarian follicles and uterine histopathology.

Fifty-six adult Wistar female rats were divided into eight equal groups (N=7) including negative control (oral normal saline/intraperitoneal normal saline), positive control (normal saline/cisplatin), T1 (vitamin C/cisplatin), T2 (inositol/cisplatin), T3 (vitamin C and inositol/cisplatin), T4 (vitamin C/normal saline), T5 (inositol/normal saline), and T6 (vitamin C and inositol/normal saline). The vitamin C and inositol were administered orally for 21 days. Cisplatin was injected intraperitoneally on the 15th day (7 mg/kg). On the day 22, the animals were euthanized, the uterus and ovaries removed, then the number of ovarian follicles and the uterine histopathology were examined.

After cisplatin treatment, the number of healthy ovarian follicles (primordial and antral) significantly decreased (P<0.05) compared to the negative control group. However, all of the atretic follicles increased compared to the negative control (P<0.05). Treatment with vitamin C and inositol increased the number of healthy follicles, effectively reduced the number of atretic follicles, and improved the damage induced by cisplatin in the uterine tissue.

Treatment with vitamin C and inositol has a protective effect on the ovaries and uterus against the toxicity caused by cisplatin.

Control of Type 2 Diabetes Mellitus (T2DM) is influenced by lifestyle. The aim of this research was to determine the predictors of treatment adherence behaviors among T2DM based on Social Cognitive Theory (SCT).

This descriptive-analytical research was done among 500 T2DM patients in Tehran during 2021. Simple random sampling was performed among patients based their medical records in the Diabetes Control Clinic of Tehran's District Five. The data collection tools were written questionnaire based on the SCT determinants. Data were analyzed using descriptive statistics (frequency, percentage, mean, standard deviation) and analytical statistics (Pearson's correlation and linear regression) in SPSS software version 16.

The mean score of treatment adherence behaviors was 56.34 [SD: 10.41], ranged from 16 to 80. The outcome expectations, perceived self-efficacy, and social support accounted for 43% of the variation in the outcome measure of the treatment adherence behaviors. Self-efficacy was the strongest predictor (Beta = 0.430 and P<0.001). Increasing age (ß= -0.126 and P= 0.004), insulin treatment (ß= -0.250 and P<0.001) and smoking (ß= -0.146 and P= 0.001) conversely and having health insurance (ß= 0.181 and P<0.001) were positively predictive of treatment adherence behaviors.

The development, implementation and evaluation of educational interventions based on SCT with emphasis on promoting perceived self-efficacy can lead to useful findings in promoting treatment adherence behaviors among T2DM patients.

Composite Lattice structures are one of the most widely used structures in the aerospace industry in recent years. These structures are composed of a large number of oblique and circumferential ribs with specific distances from each other and in addition to strength, they are very light in terms of weight. The present study includes an analytical expression and a solution to the problem of free vibrations of a composite lattice cylindrical shell. The continuous formula for calculating the natural frequency of a cylindrical lattice structure was obtained by considering the Winkler-Pasternak elastic foundation from the governing equations of the shell based on Galerkin methods. This formula, in addition to being used to estimate the frequency in the initial design phase, is also a tool for evaluating the vibration analysis of composite lattice shells in mechanical analysis. The results have been calculated analytically in two cases with and without elastic foundation and the accuracy of the results has been confirmed by finite element modeling. For finite element method simulations, Winkler and Pasternak coefficients have been replaced by shear and radial springs, respectively. The natural base frequency of the system depends on the properties of the elastic substrate, so changing the stiffness of the radial and shear springs causes a change in the natural frequencies.

According to the wide usage of energy absorbers in various engineering structures and in order to prevent damage to life and property, the analysis of behavior of absorber collapse is necessary under different loading conditions, geometric and boundary condition. In this research, collapse process of thin-walled tubes is simulating using Abaqus finite element software to validate the simulation results, the present model compared to previous experimental results. After ensuring the accuracy of numerical simulation models to investigate the effect of combined cylindrical tubes will be discussed. At first case, the tube with a circular cross-section into the tube with a square cross-section and placed under axial loading .In another case, a combination of external and internal tubes is changed. In other words, the tube with square cross-section is placed inside the tube with circular cross-section and numerical simulation is repeated. Then comparison criteria of combined cylindrical absorber collapse (including maximum crushing load, mean crushing load, the amount of energy absorption and specific energy absorption) is investigated.

In this study the ultimate amount of buckling load applied to the composite conical lattice structure located on the Winkler-Pasternak foundation has been investigated and compared by two analytical and finite elements methods. First, the governing equations of the conical lattice structure were obtained and then, by placing the conical lattice structure on the Winkler-Pasternak foundation, the governing equations were derived analytically. The effect of foundation stiffness coefficient on the behavior of conical lattice structures has been investigated analytically by considering different values. As the number of ribs and their cross section increases, the strength of the structure increases and by assuming that the conical lattice structure resting on the Winkler-Pasternak foundation, the amount of buckling load will increase and with increasing stiffness coefficient for the spring in the foundation, the buckling load resistance decreases. By comparing the analytical results and the finite element method, it can be seen that the analytical method and the obtained formula have a suitable accuracy for investigating the buckling of the lattice structure on the Winkler-Pasternak foundation.

One of the most common complications of mild cognitive impairment is increased body sway and falls. This study was performed to evaluate the effect of Pilates training on control posture in patients with mild cognitive impairment.

This clinical trial study was performed on 30 women with mild cognitive impairment who referred to elderly Research Center in Kermanshah city, north-west of Iran during 2019. Subjects were randomly divided into two groups including Pilates Training and control groups. Pilates training group was trained for eight weeks, 3 sessions per week and duration for each session was one hour. The control posture of the subjects before and after the exercise was evaluated.

There was significant difference in obtained scores in the size and distance of the center of pressure area range with open and closed eyes in the intervention group, prior and after training (P<0.05). The mean postural control (the size and distance of the center of pressure area range with open and closed eyes) reduced after 8 weeks of Pilates exercises in the intervention group in compared to control group (P<0.05).

Pilates training is effective in improving postural control in patients with mild cognitive impairment.

Food hygiene and safety is considered as an important principle to prevent humans from contracting diseases and also to protect the environment from contamination. Because a large part of Iran's population is young and a high percentage of them are students, therefore, this study was conducted to determine the knowledge, attitude and practice of students of Kermanshah University of Medical Sciences about food hygiene and safety.

The present descriptive-analytical study was conducted on 307 students at Kermanshah University of Medical Sciences through a convenience sampling method. A questionnaire including demographic characteristics and questions in three sections were used to assess students' knowledge, attitude and practice towards food health and safety. The data were analyzed using SPSS version 26 software. Ethics approval and confidentiality of answers were given on the first page of the questionnaire.

The participants were mostly male and single, with the majority belonging to the medical school. Despite the fact that most of the students had good knowledge and attitude towards food hygiene and safety, but about 70.4% of respondents showed poor performance, from which the weakest performance was related to nursing and midwifery students. Students' knowledge and attitude had a statistically significant difference between different faculties. Functionally, a significant relationship was seen between gender and performance.

Given the poor performance of students in relation to the principles of food hygiene, it seems that holding workshops and adding courses can probably improve student performance.

Hypertension is one of the most prevalent diseases affecting numerous people in different societies. One of the major complications of hypertension is the occurrence of acute renal failure. Therefore, it is important to evaluate the survival rate of patients with hypertension until the onset of acute renal failure and determine the factors affecting it.

This analytical study was conducted using modeling at the Kermanshah University of Medical Science within February 2016-July 2018. The current research examines the survival of patients with hypertension until acute renal failure using the Generalized Weibull Distribution model based on competing risks which included death due to cardiovascular disease. The required information was extracted from the Systolic Blood Pressure Intervention Trial (SPRINT) data file. 

Out of 842 patients, 85 died of cardiovascular diseases, 298 were diagnosed with acute renal failure, and 459 were censored. The mean survival time was 929.49 days and its median value was 1029 days. The Akaike value of the generalized Weibull model was less than the Weibull model. These results indicate that based on the generalized Weibull model, the variables of glomerular filtration rate, the number of antihypertensive drugs used on arrival, chronic kidney disease, albumin/creatinine ratio in urine, and gender were effective on the survival of patients.

As evidenced by the obtained results, the Akaike value of the generalized Weibull model is less than the generalized Weibull model. Therefore, the generalized Weibull model has a better fit, compared to the Weibull model.

One of the most common complications of diabetes peripheral neuropathy (DPN) is the loss of balance, postural control disorder and falling down. Therefore, the purpose of the present study was to compare the effect of resistance and aquatic exercises on balance in DPN patients in 2019, in the Shahbazi pool, Kermanshah, Iran.

This randomized clinical trial study was conducted on 30 women inflicted with DPN who referred to Diabetes Research Center in Kermanshah. The subjects were selected through convenience sampling method and were randomly divided into three groups, including aquatic exercises (n=10), resistance exercises (n=10), and control (n=10). Resistance and aquatic exercise groups had a training program of 8 weeks which included 40-minute sessions three times a week. The static and dynamic balance, simple reaction time, and choice reaction time of the subjects were evaluated before and after the exercises. Finally, ANCOVA and paired t-test were used for the data analysis. A p-value of less than 0.5 was considered statistically significant.

Both resistance and aquatic exercises resulted in improvement regarding simple reaction time, choice reaction time, and static and dynamic balance, compared to the control group (P<0.001). Aquatic exercise protocol resulted in significant improvement in static balance with the eyes closed (P<0.001) and choice reaction time (P=0.001), compared to the resistance and control groups.

Based on the results, it seems that aquatic exercises are more effective regarding balance and simple and choice reaction time in comparison to resistance exercises, in DPN patients

Considering relationship between chronic ankle instability and postural instability, and the importance of the understanding of athletes with chronic instability for rehabilitation clinics, this study was conducted to evaluate functional tests as a distinctive tools in individuals with and without chronic ankle instability.

This case-control study was conduct on 40 athletes (20 athletes with chronic ankle injury and 20 healthy athletes). In order to distinguish between athletes with chronic ankle instability and healthy athletes, they are participated in five functional tests including; Latin-Latin test, side-to-face tests, Lilli square test, Zigzag jump test for distance, single jump test for distance. For statistical analysis, test-retest, correlation coefficient and independent t-test were used at the significant level of P <0.05.

Athletes with chronic ankle instability compared to healthy athletes showed weaker function. There was a significant difference between participants with chronic ankle instability and healthy participants in performing functional tests (P<0.05). Significant correlation was found between ankle instability and eight Latin (ICC = 0.67, p <0.001), bilateral mutations (ICC = 0.75, P<0.001), square jump (ICC=0.51, P <0.001), zigzag jump (ICC = 0.82, P <0.001).

It seems that functional tests (Latin eight test, side leak test, Lilli square test, Zigzag jump test for distance, single jump test for distance) can be good tools to identify people with chronic ankle instability from healthy individuals.