Background: Measuring peak expiratory Flow Rate has been suggested as an important tool in asthma management by all international guidelines. Objective: Studies on various populations have shown considerable variations in normal values of peak expiratory Flow Rate. Since reference standards for Iranian children are not available, the present study was performed to establish these standards. Methods: This study was conducted on 1535 normal schoolchildren (767 female, 768 male), aged 6-14 in Tehran. A mini Wright peak Flow meter was used to measure peak expiratory Flow Rates. The highest of the three readings was taken as the correct value. Regression analysis was used to calculate the predicted normal values of peak expiratory Flow Rate and also to assess its relationship to age, weight, height, and surface area. Results: Peak expiratory Flow Rate values increased with age and were in strong correlation with the studied anthropometric measurements. Except for the 145-159 cm interval, the male children showed significantly higher values (P<0.01) of peak expiratory Flow Rate in comparison to female children. Conclusion: The peak expiratory Flow Rates for Iranian schoolchildren were similar to some of those reported from other countries and could be used by Iranian physicians for proper management of paients.

Background and aim: Side effects of cigarette smoking are among the major concerns. These complications can adversely affect the oral environment. Since reduced salivary Flow Rate increases the incidence of tooth decay and other dental and oral problems, the present research aimed to investigate the relationship between cigarette smoking and salivary Flow Rate. Materials and Methods: In this historical cohort study, 50 cigarette smokers (case) and 50 non-smokers (control) were involved, who were matched according to age and gender. Non-stimulated whole saliva was measured by using the modified Schirmer test (MST) performed between 9 a. m. and 12 p. m. by a trained examiner. All the participants refrained from eating, drinking and smoking for 2 hours prior to the study. The subjects were asked to sit in an upright position and to raise and slowly retract their tongue, to avoid unintentional wetting of the Schirmer test’ s strip. The strip was kept vertically with the help of cotton pliers, while the bottom of the paper was in contact with the floor of the mouth. The length of the wet area on the strip was recorded at the intervals of 1, 2 and 3 minutes. Data were analyzed with Mann-U-Whitney and Chi-square tests. Results: The quantitative value of salivary Flow Rate was equal to 24. 8± 2. 4mm in controls, and 15. 8± 2. 1mm in the case group (P<0. 001). 30% of non-smokers and 90% of smokers exhibited reduced salivary Flow Rate (P<0. 000). Conclusion: It seems that reduced salivary Flow Rate is more significant in cigarette smokers than in non-smokers.

A project was established to develop a procedure for the selection, design, installation, test and evaluation of mass-Flow Rate measurement systems for root crop harvesting and to assess the consistency and precision of the weighing systems incorpoRated into crop feed arrangements in both laboratory and field studies. Studies were conducted to evaluate conveyor belt weighing systems using an experimental apparatus and a commercial potato harvester. Two weighing systems were evaluated: (a) cantilever transducers fitted to the conveyor belt mechanism and (b) a load cell system supporting the total weight of the conveyor and crop. The results of laboratory studies with sugar beet/potatoes showed that the standard cantilever transducers gave the smallest percentage of standard deviation from the mean experimental error ranging from 1.43 kg (connected to one idler roller) to 2.61 kg (connected to three idler rollers) with an appropriate value equal to 0.54 kg (connected to two idler rollers). The load cell supporting system also gave the smallest percentage of standard deviation from the mean experimental error ranging from 1.56 kg (continuous side feeding) to 2.25 kg (side feeding from right side) with an appropriate value equal to 0.84 kg (steady state side feeding). Experiments were conducted in the laboratory and field to assess the effects of belt inclination and extraneous vibration, transferred from the tractor to the harvester, on the measurements of crop mass. The results of field studies with potatoes using the cantilever transducers showed that the most precise system performance was obtained when using the 125 mm idler wheels with standard deviation of the mean experimental error of the sample yield equal to 0.99 kg. The results of barn studies with potatoes using the load cell supporting system showed that there was a good linear relationship between the measured and weighed mass of the potato samples with standard deviation of the mean experimental error equal to 0.34 kg.

Introduction: At present, the peak urinary Flow Rate (Qmax) is widely used in evaluating patients with benign prostatic hyperplasia (BPH). Cystoscopy is another method used by many urologists to evaluate BPH cases. To evaluate the correlation between the Qmax and obstructive indices of cystoscopy in patients suffering lower urinary tract symptom due to BPH.Methods: This study was performed on patients with lower urinary tract symptom (LUTS) due to BPH. All included patients were evaluated by uroFlowmetry to determine the Qmax and then cystoscopy was performed to evaluate kissing lateral prostate lobes, median lobe presence, bladder neck elevation, elongation of urethrae and bladder trabeculation. Data were compared and analyzed.Results: 154 patients with the mean age of 65±9 years were evaluated. There was a significant difference between the mean Qmax and severity of kissing lateral prostate lobes, elevation of the bladder neck, and bladder trabeculations (P-value≤0.05). Moreover, Qmax had a significant negative correlation with the severity of those parameters.Conclusion: According to present study, severity of kissing lateral prostate lobes, elevation of the bladder neck, and bladder trabeculations inversely correlate with peak urinary Flow Rate and can be used instead or in combination.

Airway mucus hypersecretion Health effects caused by air pollutants may range from subtle biochemical or physiological signs, such as mildly reduced lung function, to difficult breathing, wheezing, coughing and exacerbation of existing respiratory conditions such as asthma. The aim of this study was measuring the adverse health effects of air pollution on lung function of primary school students.The lung function of students was measured daily for seven weeks in two elementary schools in District 12 of Tehran, after obtaining permission from the two principals and signed parents’ consent forms. Twenty four hourly air pollution levels were used as potential predictors of lung function. The principal analysis conducted was a logistic regression on a subset of the data using a case-crossover design.The outcomes data consisted of the results of lung function tests for 356 female and 206 male students over the six-week period. Using the difference between mean (87) and maximum (125) concentration of moving average of NO in this period to judge the size of the effect, such an increase in NO is predicted to lead to an increase in the probability of poor lung function (OR=20) based on population-based predicted value.This study has shown strong and consistent associations between children’s poor lung function and outdoor air pollutants in District 12 of Tehran for some pollutants. The strong association found in this study was an increase in seven-day moving average of NO using both definitions.