Background: Caffeine is isolated Methyl-xanthine, Alkaloid stimulants and it is the most commonly used drug in the world. The present study was to investigate the effect of caffeine on VO2max and Electrocardiograph in active male of student college after Bruce exhaustive exercise. Methods: 9 male active aged 25 (mean 20. 9± 1. 37 years, fat percent 11. 21± 3. 79 percentage and BMI 23. 49± 1. 69 kg/m2) allocated into two equal conditions: the supplement (5 mg. kg-1 caffeine) and without caffeine consumtion. After 60 min supplementation, subjects were participated in a single session of exhaustive Bruce Test. Changes in the VO2max and QT interval distance were meatured. Results: The results showed that caffeine had significant effect on the increased levels of VO2max after Bruce exhaustive exercise compared to the control condition. Also, levels of QT interval increased significantly after the exercise (p<0. 05). Conclusion: Caffeine could significantly increase the VO2max and increase QT after Bruce exhaustive test. Maybe, level and severity of exercise increase the ventricular depolarization and repolarization and cardiac performance.

Improving participation in voluntary activities in Iran is important because increasing productivity among young people, given the country's young population, contributes to community sustainability. Therefore, a better understanding of volunteer motivation in Iranian youth is needed. The Volunteer Functions Inventory (VFI) for assessing volunteer motivations has good psychometric properties and is adapted to several languages, but no validated Iranian translation yet exists. The purpose of this study was to investigate the psychometric Characteristics of voluntary functions inventory in members of Iranian Red Crescent Society. Sample size was 595 members of Youth Organization of Iranian Red Crescent Society from 31 provinces and 175 cities of Iran that were selected by multi-stage cluster sampling method and responded to voluntary functions inventory. Data were collected using a demographic sample and voluntary functions inventory (VFI). Confirmatory factor analysis using principal components method was used for data analysis. The results of the present study showed that the voluntary functions inventory had validity and reliability. Also, the factor structure showed that 29 items and 6 factors well assess people's attitudes to volunteering, and the structure of this inventory was well-fitted and confirmed all goodness of fit models. The present study provides the use of the Iranian translation of the Voluntary Functions Inventory (6 scales and 29 items) to assess volunteer motivation among young Iranian volunteers.

Many remote diagnostics systems rely on transmission and reflection of electromagnetic waves. In diagnostics facilities such as microwave reflectometers which operate in the cut-off frequency range, collisionality of the plasma can affect the transmission and reflection characteristics of the electromagnetic wave. In this paper, plasma mismatching and reflection properties of microwave propagation through partially ionized, uniform, and cold plasma were studied. Using the simplified Lorentz model of the plasma and associated dispersion relation of electromagnetic wave propagation through collisional, cold plasma, propagation characteristics of the electromagnetic waves were investigated in different collisional regimes of single-interface and double-interface, bounded plasma. It was found that in the cut-off frequency range, the propagation coefficients of the electromagnetic wave can be significantly affected depending on the collision frequency of the plasma. It was also found that in the double-interface case, the thickness of the plasma can cause multiple reflections in the plasma slab, and such reflections can be suppressed in the high-loss collisional regime

Background and Aim: Job enrichment is a method that has been used to increase employee satisfaction and work motivation. The Hackman and Oldham job characteristics model (1976) has served as the foundation for many job enrichment efforts. In particular, a considerable amount of research has been devoted to the study of the job characteristics-job satisfaction relations. Te purpose of this study was to statistically determine the relation between job characteristics and job satisfaction among employees of hospitals affiliated to Tehran University of Medical Sciences (TUMS) in 2007. Materials and Methods: This study was a cross-sectional one, including 6 TUMS-affiliated hospitals-Emam, Shariati, Baharlo, Ziaeian, Madaen and Azadi. The sample size was 400, consisting of 200 administrative employees (50%), 151 nurses (38%) and 49 physicians (12%). The random sampling and stratified proportional sampling methods were used to select the hospitals and interviewees, respectively. Two questionnaires were developed and used to identify job characteristics and job satisfaction: 1) job diagnostics surveys (JDS) and 2) Hertzberg's job satisfaction questionnaire. The reliability of the questionnaires was ascertained by test-retest using the Pearson correlation coefficient (r = 0.88). Linear-by-linear association and ordinal logistics regression analysis were used for analyzing the data gathered.Results:The relations between the Motivational Potential Score (MPS) and job characteristics (except for feedback) with job satisfaction were statistically significant (p<0.05). Task identity was the most effective determinant of job satisfaction. Conclusion: It appears that all the job characteristics (except feedback) are important determinants of job satisfaction of the hospital employees. Although the work environment is in need of restructuring, it is important to note, from a positive perspective, that the job characteristics discussed in this study are readily amenable to change job satisfaction at the organizational level.

Background: Endometriosis is a gynecologic disorder which causes dysmenor-rhea and infertility. Early diagnosis of endometriosis can help prevent the ne-cessity for invasive diagnostic procedures. Medical imaging has been widely utilized to diagnose various diseases without the need for invasive procedures. The purpose of this study was to investigate the cervical length in women with endometriosis. Methods: In this case-control study, the case group consisted of nulliparous women with endometriosis, while the control group comprised nulliparous women without endometriosis. A total of 42 individuals were included in each group. Cervical length was measured using transvaginal ultrasound from the external os to the internal os. The patients in the case group underwent laparoscopy to confirm the diagnosis. Pearson chi-square test and Fisher’s exact test were employed to compare categorical variables with a p<0. 05 considered statistically significant. Results: In both groups, there were no notable variations in any of the demographic characteristics. However, the severity of dysmenorrhea was significantly different between the two groups (p=0. 01). The average diameter of the mediolateral cervix (29. 48±6. 2 and 27. 14±3. 8) was statistically significant between the patient group and control group, respectively (p=0. 04). The mediolateral width may have a positive predictive effect on the presence of endometriosis, while cervical length appears to have a protective effect against endometriosis. Conclusion: Demographic data do not predict endometriosis. This study sug-gests that mediolateral width in transvaginal sonography can serve as a minimal-ly invasive diagnostic tool for endometriosis, showing correlation with endome-triosis symptoms like dysmenorrhea and dyspareunia.

Evaluating the cutting rate (CR) of stones is important in the cost estimation and the planning of the stone processing plants. This research used regression models to estimate the stones’ CR based on their physico-mechanical characteristics. Stone processing factories in Mahallat City (Markazi province, Iran) were visited, and the CR of diamond circular saws was recorded on six different travertine stones. Next, the stone block samples were collected from the quarries for laboratory tests. Stones’ porosity (n), uniaxial compressive strength (UCS), and Schmidt hammer hardness (SH) were determined in the laboratory as their physico-mechanical characteristics. Correlation relationships of CR with physico-mechanical characteristics were evaluated using simple and multiple regression analyses, and estimator models were developed. Results showed that multiple regression models are more reliable than simple regression for estimating the stones’ CR. The validity of the developed multiple regression models was verified with the published data of one researcher. The findings indicated that these models are accurate enough for estimating the CR of stones. Consequently, the multiple regression models provide practical advantages for estimating the CR and save time and cost during the planning and design of the stone processing factories.

Coronary circulation anatomy in patients with transposition of the great arteries (TGA) is a major challenge for surgeons before the arterial switch operation (ASO) since the coronary arteries need to be transferred if any abnormal pattern exists. Therefore, having information about the coronary pattern before the ASO plays an important role in preoperation planning. Echocardiography is an acceptable, easy-to-perform, and noninvasive tool for the determination of coronary circulation,however, its diagnostic characteristics have not been numerous up to present...

Objectives: The aim of this study was to evaluate the clinical characteristics and diagnostic stability of children and adolescents with bipolar disorder.Method: In this prospective study, 257 subjects with bipolar disorder who were consecutively admitted to Roozbeh Hospital (Tehran, Iran) were enrolled. Demographic characteristics, diagnosis, treatment, comorbid disorders and mood and psychotic symptoms were extracted from the patients' admission files and the information questionnaire, which had been filled in the admission time by the patients. In the further assessment, diagnostic evaluation was done using the Schedule for Affective Disorders and Schizophrenia for School aged children present and lifetime version (K-SADS-PL), for the patients under 18, and the Schedule for Affective Disorders and Schizophrenia (SADS) for the patients older than 18. Severity of the symptoms in the acute phase of mood disorder was evaluated by the Young Mania Rating Scale (Y-MRS) in manic phase and Beck Depression Inventory (BDI) for patients older than 16 or Children Depression Inventory (CDI) for the patients under 16 in depressive phase. Also, current and past levels of functioning were evaluated by the Global Assessment of Functioning (GAF) scale for patients older than 18 and the Child Global Assessment Scale (CGAS) for the patients under 18.Results: The most common symptom, irritability, was accompanied by elated mood in most cases.73.2% of the patients had at least one comorbid disorder and the most common comorbid disorder was Attention Deficit Hyperactivity Disorder (44.2%). Diagnostic stability in all periods of illness was higher than 80%.Conclusion: This study supports the high diagnostic stability of bipolar disorder in both children and adolescents.

Introduction: Hepatopulmonary syndrome (HPS) is one of the pulmonary complications of cirrhosis, which is manifested by reduction in arterial blood oxygen. The present study was conducted to evaluate the frequency, clinical and para clinical features of HPS, and to determine their predictive values in diagnosis in a group of Iranian patients.Materials and methods: This case series study was performed on 54 cirrhotic patients referred consecutively to the gastroenterology department of Taleghani Hospital between 2003 and 2004. Patients underwent pulmonary echo-contrast to detect intra-pulmonary and intra-cardiac shunts. Arterial blood oxygen, 02 gradient (A-a) and orthodoxy were measured in these patients by ABG. All patients underwent endoscopy for possible esophageal varices. Patients who met the following three diagnostic criteria including hepatic cirrhosis, arterial blood deoxygenation (P02<80mmHg) and intrapulmonary arterial dilation were classified as clinical HPS while those manifested solely with intrapulmonary arterial dilation were defined as subclinical HPS.Results: Of 54 patients, 10 (18.5%) fulfilled clinical and 7 (13%) subclinical HPS criteria. Patients aged 71-80 years were more commonly affected. Hepatitis B was the most common etiologic factor. Dyspnea (100%) and cyanosis (90%) were the most prevalent clinical features. Dyspnea and clubbing were the most sensitive and specific clinical features, respectively. Pao2<70mmHg and arterial-alveolar gradient had the highest sensitivity for HPS diagnosis. Conclusion: Clubbing with the highest positive predictive value (75%) and dyspnea whit the highest negative predictive value (100%) were the best clinical features to diagnose HPS. PaO2<70mmHg and P(A-a)02>30 and their sum, have the highest positive and negative predictive values in HPS diagnosis.

Background: Exudative pleural effusion (EPE) is a common clinical syndrome in internal medicine. Early diagnosis of EPE is important because it is a common presentation of several diseases with different prognosis. The purpose of the present study is to determine the etiology, clinical characteristics of EPE, and to evaluate the diagnostic methods. Materials and Methods: In this cross-sectional study, patients with EPE hospitalized in pulmonary division of Shaheed Beheshti hospital between 1996 to 2002 were studied. Diagnosis of pleural effusion was verified by clinical examination, Chest x-ray and thoracenthesis. EPE was confirmed by light criteria. Definitive diagnosis of tuberculosis pleurisy (TbP) was confirmed by the identification of acid fast bacilli (AFB) from the pleural fluid, biopsy sample or histological findings of granulomas with causes necrosis concomitant with compatible clinical and radiographic findings. Malignant pleural effusion (MP) was verified by finding bf tumor cells from the pleural fluid or tissue specimens. Other diseases were diagnosed by appropriate clinical and laboratory findings. Results: 100 consecutive patients (male, 62%) with EPE with mean age of 5717 (12-82) years were studied. Right sided pleurisy was observed in 44% and both sides in 5% of patients. The most common causes of EPE were malignant diseases and Tuberculosis which accounted for 41% and 33% of cases respectively. 95.3% of MP were due to met static caners and 4.6% were due to malignant mesothelioma. Other causes which accounted for 24% of patients included; parapnemonic effusion (6%), heart failure (3%), coronary bypass surgery comp0lication (2%). Rheumatoid arthritis (2%), lupus erythematos (1%), chronic renal failure (1 %), coexistence of Tb and malignancy (2%), and unknown etiology (8%). Pleural biopsy was the best diagnostic method for TbP, and pleural fluid cytology was the best diagnostic method of MP. Pleural fluid analysis detected TbP, and MP in 33% and 70% of cases (P<0.001) and pleural biopsy in 70% and 53.5% of cases respectively (P=NS), whereas both tests detected 97% and 91% of cases with Tb and MP. Conclusion: Even in geographic region with a high prevalence rate of tuberculosis, malignant diseases should be considered as a cause of EPE.