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Background: The airway surface liquid (ASL), which is a fluid layer coating the interior epithelial surface of the bronchi and bronchiolesis, plays an important defensive role against foreign particles and chemicals entering lungs. Objective: Numerical investigation has been employed to solve two-layer model consisting of mucus layer as a viscoelastic fluid and periciliary liquid layer as a Newtonian fluid to study the effects of cilia beat frequency (CBF) at various amounts of mucus properties on muco-ciliary transport problem. Methods: Hybrid finite difference-lattice Boltzmann-method (FB-LBM) has been used to solve the momentum equations and to simulate cilia forces, and also the PCLmucus interface more accurately, immersed boundary method (IBM) has been employed. The main contribution of the current study is to use an Oldroyd-B model as the constitutive equation of mucus. Results: Our results show that increasing CBF and decreasing mucus viscosity ratio have great effects on mucus flow, but the effect of viscosity ratio is more significant. The results also illustrate that the relation between cilia beat frequency and mean mucus velocity is almost linear and it has similar behavior at different values of viscosity ratio. Conclusion: Numerical investigation based on hybrid IB-FD-LBM has been used to study the effect of CBF at various mounts of mucus viscosity ratio on the muco-ciliary clearance. The results showed that the effect of viscosity ratio on the muco-ciliary transport process is more significant compared with CBF.

Background and Objective: Acquired immunodeficiency syndrome (AIDS) is a definition of dysfunction of immune system in human that is induced by infection with a virus named human immunodeficiency virus (HIV). The most high risk group in HIV infected people are intravenous drug users (IDUs) with unsafe sex. This study was conducted to evaluate knowledge and attitude of IDUs with unsafe sex about AIDS and relation with socioeconomic levels in Golestan province in North of Iran. Materials and Methods: This Cross-Sectional study was conducted on 134 IDUs in Golestan province during 2007. Samples were chosen by a random systematic method. Data was collected with interview by standard questionnaire. Data was analyzed by SPSS-16 and One-way ANOVA,T-test student, Kruskal-wallis, Mann-Whitney U and Kendall tests. Results: This study showed that 36.6% of samples had moderate knowledge about AIDS and 49.3% of them had negative attitude about AIDS. 67% of subjects had education between 6-12 years, 44.8% were married and 53% were jobless and without income. Level of knowledge had a significant relation with age (P

Background: a number of factors such as socio-demographic and socioeconomic status have emerged as being associated with smoking. The main goal of the present study was to identify the relationship of socio-demographic factors and cigarette smoking, and to determine the indicators of smoking status in a community based case-control study.Methods: Using the random multistage cluster sampling method on the basis of family list kept in the health center, a head cluster was selected, and 25 clusters of 10 members each were chosen. One member was selected from each family to fill the questionnaire. The neighborhood method was used for selection of controls. The socio-demographic characteristics was assessed by a self administered questionnaire. Data analysis was performed using SPSS V-11.5 software. Logistic regression was used to assess the association of age, sex, marital status, family size, number of close friends, number of smoking friends, and presence of smokers in the family with smoking status. Results: The mean smoking consumption of smokers in this study was 14.6 per day. The mean age of smoking initiation was 18.6 years. Fifty percent of people initiated smoking at ages less than 18. The mean years of education were significantly higher in nonsmokers. A significant inverse relationship exists between the number of cigarettes smoked per day and educational levels. The positive association between number of cigarette smoked per day and age was found (OR=1.2, CI 95% 1.07-1.4). Number of smoking friends in smokers were significantly more than in nonsmokers. Multivariate analysis revealed that age, and number of smoking friends, could be predictors of smoking status. The association between sex, marital status, family size, and education with smoking status were not significant. Conclusions: This study revealed the association between several socio-demographic factors with smoking status. Antismoking strategies for adults tend to emphasize smoking cessation, preventing smoking initiation is also important during young adulthood. Anyway, educational interventions are highly suggested.

Background: This study attempts to examine the relationship between several dismension of organization climate and medical facutly's job satisfaction in Tehran University of Medical Sciences. Methods: A survey composed of demographic items and job satisfaction indexes were mailed to a stratified random samples of medical faculties (n= 405).Results: The overall response rate was 45.1%.Conclusion: The study indicates that score of job satisfaction was 56.5 with SD= 16.96. In general 47.4% of the medical faculties were highly satisfied.A significant statistical correlation have been found between sex (p= 0.008), administrative position (p= 0.044), faculty rank (p= 0.007), marital status (p= 0.001), employment status (p= 0.003) and job satisfaction.The findings of this survey have implications for university administrative.

Background: The stenosis or occlusion of subclavian artery proximal to origin of internal mamary artery (IMA) may cause reversal of the flow of this vessel to subclavian artery and if IMA has been used as a conduit for myocardial revascularization it may cause myocardial and/ or brain ischemia.Case report: The reported patient had diffuse coronary and peripheral atherosclerosis and stenosis of the proximal left subclavian artery, who developed symptomatic myocardial ischemia resulting from coronary- subclavian steal syndrome as a result of flow reversal of IMA, used for bypass surgery, treated by subclavian to subclavian graft surgery.Conclusion: Because subclavian artery stenosis is very important in patients who are candidate for CABG, and it has a low incidence, authors suggest that before coronary angiography blood pressure of both hands should be measured for screening, and if more than 20 mmHg difference is observed, subclavian artery angiography is recommended. This approach is emphasized in those with history of peripheral artery disease.

Background: Surgery operations are the fearful events among all other medical procedures. This fear causes anxiety and stress which affects the outcome of treatments, recovery from surgery and some maladaptive behaviors. To cope with surgery worries and minimize the fear, it is important to study these fears and its associated factors. This study attempts to explore the surgery worries and the associated factors among Iranian high school adolescents.Methods: To measure surgery worries, high school adolescents of age 11-15 completed the Child Worries Questionnaire (CPCI) adolescent form, and also answered the questions about the 14 independent variables (sex, age, parents education and occupation, previous hospitalization experience of child and immediate family and friends, number of hospitalization during Child's life long, previous surgery experience of child and her or his immediate families, death of close friends in hospital). Multivariate regression method was used for statistical analysis to determine the effective factors.Results: The results of this study showed that the Iranian Adolescents have most worries about the "Not being able to do the same things as before" and least worries about "What I will feel during the anesthesia". The factors associated with Surgery worries are; parent's education (P=.021 for father and 0.049 for mother), adolescent previous experience and number of hospitalizations (P=0.025 and P=0.008, respectively), the number of previous hospitalizations (P=.003), previous experience of hospitalization of immediate family and friends (P=0.035). The findings of this study have implications for parents, family, hospitals' staff and care given.Conclusions: It seems, according to the findings of this study, there should be a special educational program for children who are going to be operated in a hospital ward to reduce their worriships.

Background: Kernicterus, also known as bilirubin encephalopathy, is a neurologic syndrome resulting from the deposition of unconjugated bilirubin in the basal ganglia and brainstem nuclei. Indirect bilirubin is toxic for brain. Neurologic dysfunction (BIND) that include acute phase (hyperbilirubin encephalopathy) and chronic phase (Kernicterus) resulting from hyperbilirubinemia and disruption of blood brain barrier. In this study, the association between bilirubin encephalopathy and risk factors was evaluated. Methods: In this retrospective study, 312 icteric neonates were admitted in the neonatal ward of Children's Hospital, Medical Center, Tehran, and 305 of these cases were evaluated. Patient histories were taken and physical examinations were performed. For each patient, the age, sex, birth weight, time of discharge from the hospital and risk factors were recorded, and a questionnaire was completed. Results: In this study, of the 305 icteric neonates evaluated, 25 cases had kernicterus. Risk factors included acidosis, prematurity, hemolysis, hypoglycemia, sepsis, respiratory distress, low birth weight, ABO incompatibility and G6PD deficiency. The mean level of bilirubin in cases of kernicterus was 32 mg/dl and in the others was 20 mg/dl (p=0.001). Kernicterus was most common among high risk neonates (p

Background & Aim: Osteoporosis is a metabolic disease which is the result of gradual destruction of bone mass and its most serious and frequent complication is hip fracture. Because adolescent females are the high risk group of affecting this disease, the purpose of this study was to assay female students’ knowledge’s about osteoporosis and its risk factors. Methods & Materials: A cross-sectional study with a 31-item questionnaire was used in this research. A convenience sample of 1000 adolescents in grade 1-3 who attended at 6 high schools participated in this study. Using SPSS software, the data were analyzed by chi2 and T tests. Results: According to 22 questions about knowledge, sufficient knowledge of students was estimated 40.8%. Among 10 factors related to the family, only correlation between father occupation and knowledge was significant statically (p=0.049). Knowledge was higher in independent- medicine versus dependent medicine occupations. Conclusion: Overall, the knowledge of these assayed female students about this disease and its risk factors including sex, race, smoking, sun exposure, exercise, calcium- rich foods and menopause and its complications was limited.

Objectives: To assess one-month drug compliance and some of the factors that influences it in a sample of diabetic patients. Methods: This was a cross-sectional study carried out from April to September 2004. In this study, 256 diabetic patients in Shariati and imam Khomeini hospitals were assessed in terms of one-month drug compliance and their knowledge about diabetes, their attitude regarding drug usage, family support, drug accessibility and other factors that probably influence compliance. Results: 221 patients (86.3%) had drug compliance levels of ≥90% during the month preceding the study. The associations between drug compliance and age, knowledge, patients’ attitude about controlling of diabetes and drug effectiveness were significant (P

Objective(s): To develop and validate a clinical tool to help physicians to identify which women are at increased risk for osteoporosis and should therefore undergo further testing with bone densitometry. Methods: Using the Endocrine and Metabolism Research Center (EMRC) database and postmenopausal women in Iranian Multicenter Osteoporosis Study (IMOS) who had undergone testing with dual-energy x-ray absorptiometry (DEXA) at femur and lumbar spine (L1-L4). The main outcome measure was low bone mineral density (T score of 2.5 or more standard deviations below the mean for yoi. ng adult women) at femur, Lumbar spine or both sites. Logistic regression analysis was used to identify the simplest algoritlun that would identify women at increased risk of low bone mineral density. Results: The study population comprised 4229 individual of whom 2148 women with menopause were selected; and 185 postmenopausal women from (IMOS) were also included. A simple algorithm based on age, weight, duration of menopause was developed. Validation of this 3 - item Iranian Osteoporosis Scoring System (IOSS) showed that the tool had a sensitivity of 61.7% and specificity of 72.4% for women with osteoporosis. Conclusion IOSS can identify the majority of women likely to have low bone mineral density and is effective in substantially decreasing the need for all women to undergo DEXA testing.

Objective(s): Osteoporosis remains a major problem following kidney transplantation. Radiographic measures of bone mass are of limited predictive value after transplantation and are complicated by preexisting renal osteopathy. Quantitative ultrasound (QUS) is a new and noninvasive method to assess skeletal status. However, limited data exist on ultrasonic bone parameters of phalanx after renal transplantation. We evaluated this method in osteoporosis diagnosis in renal allograft recipients in comparison to DXA. Also QUS results in these patients were compared to results of normal matched controls. Methods: Forty-two patients (age 40.17 ± 11.9 years) were studied 2.8 ± 2.9 years after transplantation. We used 49 healthy matched individuals for age and sex as controls. A Lunar device (DPM-MD) was used for DXA scanning and QUS of phalanx was done in all using a DBM-Sonic 1200 device. Results: Osteoporosis found in 19% of all patients (9.5% in femoral neck, 9.5% in total region of femur and 9.5% in spinal region). Sensitivity of Ad-SOS (parameter measured with DBM-Sonic 1200) for osteoporosis diagnosis in above regions was respectively I 00%, 75% and 25% and its specificity for that diagnosis in above regions was respectively 45%, 43% and 37% (there was not significant relation between them). Mean of Ad-SOS (amplitude dependent speed of sound, the parameter measured in QUS of phalanx) was 2036 ± 79 in transplanted patients and 2060 ± 86, in controls. There was no significant difference between two groups. Age, height and BMI were significantly related to Ad-SOS. Age and BMI had negative relation with Ad-SOS (P-values 0.027 and 0.001).Ad-SOS had a positive relation with height (P-value = 0.013).There was no correlation between Ad-SOS and weight, dialysis time, time after transplantation, cumulative steroid dose and cumulative cyclosporine in transplanted patients. Conclusion: Our data suggests that QUS of phalanx is not a good way for assessing the changes of bone in renal transplanted patients in comparison to healthy individuals, but may be used as a screening technique for osteoporosis. For establishment of diagnosis, patient must be examined with DXA.

Objective(s): To study of the effects of women reproductive factors on heel QUS parameters and comparison of it with BMD of femoral neck in normal women of Tehran. Methods: In 151 normal women, 20 - 72Y/0 (participant of IMOS (Iranian Multicenter Osteoporosis Study), BMD (DXA) of femoral neck and QUS of heel (using Achilles+) was assessed. After assessment of normal values, Stiffness Index (SI) percentiles (2.5, 50, 97.5) in them established. Results: Mean values of BMD, SOS, BUA and SI, was 0.908±13.7,36/75± 1527/25, 121/42 ± 15/1, 94/46 ± 17/92, respectively. BMD and QUS parameters showed a significant decrease with age (P

Objective(s): The objective of this study was to determine coping with stress abilities of clinical residents at Tehran University of Medical Sciences and to explore whether these abilities differ between Junior and Senior residents or between males and females. Material & Methods: In this cross-sectional study, The Coping Skills Inventory was used for determination of different aspects of coping in a randomly selected sample of clinical residents in 14 different specialties at Tehran University of Medical Sciences. Results: In all 277 residents were studied. Of these 62.7 percent were at the first or second years of residency, while the other 3 7 .5 percent were at the third or fourth years. The male to female ratio was 1.1. The mean coping score was 64.83. Excellent and very good abilities were observed in 79.8%. The mean self-estimated coping scores was 63.13 that was significantly correlated with the calculated scores (Pearson correlation =0.47, P < 0.001). The mean coping score for Juniors was not significantly different from that of Seniors; but, Juniors were less flexible, resourceful and self-reliant than their Senior counterparts (P = 0.016, P=0.005 and P=0.006, respectively). A significant difference was observed between the mean coping score of females and males (P< 0.001). The most important stressors were sensitive responsibilities, low salaries and sleep deprivation. Long hours of work, nightshifts and multiple roles were more frequently reported by the Juniors than Seniors as major stressors (P= 0.001). Conclusion: Although a high percentage of residents had very good coping scores. However the difference in coping between genders emphasizes on the importance of support and education for female residents to cope more effectively with their job stress.

Objective(s): To determine the frequency of depression among pregnant women visited at the prenatal clinic, Imam Khomeini Hospital, Tehran, Iran. Material & Methods: This was a cross-sectional study in which by convenience sampling, pregnant women visited at the prenatal clinic during a 2-month period were studied. The instrument for data collection was Beck Depression Inventory, which is a self-administered valid and reliable questionnaire, measuring manifestations of depression. Scores higher than 9 were interpreted as depression. Results: Of 170 pregnant women, 16.5 percent had experienced depression symptoms before pregnancy, 9.4 percent reported depressive episodes in their relatives, 4.7 percent had suffered from depression during/after previous pregnancies and 8.2 percent had the history of premenstrual depression. 48.2 percent had experienced at least one stressor during the current pregnancy. The mean score on Beck Inventory scale was 11.47 (95%CI= 10.09-12.58). At the time of the study, at least 30.6 percent suffered from depression. Nevertheless, none were under supervision of a heath care professional for management of depression. Conclusion: The findings suggest that the implementation of strategies to integrate mental health screening in prenatal cares is needed.

Objective (s): To determine the reasons why pregnant women refuse to attend government-run prenatal care facilities. Methods: Subjects were 300 pregnant women who did not regularly attend prenatal care facilities in the city of Sari. Using a standard questionnaire, using a standard questionnaire, data were collected on demographic characteristics as well as attitude and satisfaction regarding slate-run clinics. Results: Fifty-four women (18%) attended both government and private care facilities. The remaining 164 subjects (55%) only visited private clinics. The most important causes of refusal to attend public-sector facilities were: desire to be cared for by a specialist (32%), limited knowledge of State facilities (13%), and dissatisfaction with staff behavior in the public sector (l l %). Conclusion: Lack of standardization in instruments, buildings and providerschr('39') skills seems to be the main reasons why pregnant women refuse to attend public-sector clinics. To increase attendance rates, we suggest that state-run centers enhance the quality of their services and promote physical standards as well as providerschr('39') skills.

Enhancing the terahertz emission at hybrid resonant frequencies is observed from a warm collisional inhomogeneous plasma irradiated by intense laser beams in the presence of an external transverse magnetic field. To reach this result, we utilize the dielectric permittivity tensor of the plasma affected by the strength and the direction of the magnetic field and analyze the nonlinear current density induced by the ponderomotive force due to the beating of two Gaussian laser beams. The calculations reveal resonance emission at several frequencies, which depend on the thermal speed of the electrons, the wavenumber, the electron plasma frequency, the collision frequency, and the cyclotron frequency. However, the amplitude of THz waves at these frequencies mainly depends on the electron temperature as well as the external magnetic field strength. [ABSTRACT FROM AUTHOR]