مجله علمی پژوهان
سال پانزدهم شماره 4 (تابستان 1396)

The Electrochemical process has high performance efficiency in nitrate removal. And the process may change the values of the residual chlorine dosages, hardness and alkalinity alongside nitrate removal. In this study, the changes of these parameters during the electrochemical denitrification process were studied.
This experimental study was performed on synthetic wastewater in a reactor with an effective capacity of 3.5 L having carbon cloth and stainless steel mesh electrodes and powered by direct current (DC). The initial nitrate concentration was fixed in range of 50-150 mg/L in experiments. Moreover, the impacts of applied current density (5-60 mA), NaCL dosage (0.5-2 g/L) and initial pH (4, 7 and 9) on the changing free residual chlorine, hardness and alkalinity over the electrochemical denitrification process were studied.
A relative decline was observed in the levels of alkalinity and calcium hardness by the contact time of 60 min with increasing NaCl dosage. The amounts of all parameters leveled off with rising contact time. Free residual chlorine was detected at 2 g/L of NaCL dosage and initial PHS of 7 and 9. In pH of 9, residual chlorine decreased to zero by increasing contact time from 60 to 120 min, while, in pH of 4, residual chlorine was generated after 40 min of contact time. The residual chlorine at the end of the electrochemical denitrification was achieved only at the initial pH of 9 without NaCl addition.
According to the obtained results, the proposed electrochemical denitrification process can remove nitrates, while other water quality parameters such as hardness and alkalinity remain approximately unchanged. Therefore, by this process the selective removal of nitrate can be achieved.

Giardia lamblia is one of the main causative agents of debilitating diarrhea and occurs in endemic and epidemic forms among children and travelers all around the world. The aim of this study was determining the prevalence and associated risk factors of giardiasis among hospitalized and health care centers patients of Hamadan city.
This study was accomplished on people admitted to the hospitals and health care centers of Hamadan during 2014 to 2015. After getting informed consent and recording of demographic data and clinical symptoms, faucal samples of volunteers were examined, using direct wet preparations and the suspicious samples were tested by formalin-ether and trichrome staining procedures. The data were analyzed with Chi-square and Fisher's exact tests. The level of significance was set at 0.05.
From a total of 4066 (2004 male and 2062 female, with a mean age of 32 years) examined people, 64 (1.6%) were infected with G. lamblia. The incidence rate for males was nearly twice as great as females (2.09% vs. 1.05%) (P Although the results showed the relatively low prevalence of giardiasis in Hamadan (1.6%), but due to complications of giardiasis such as malnutrition and failure to thrive, especially in children, promotion of public health especially providing safe drinking water must be considered for the prevention and control of the infection.

Oral and dental health is essential for mothers and fetus during pregnancy. Ignoring this issue influences not only oral problems but also other body systems of both mother and fetus. One of the practical strategies in this regard is health education. Therefore, the aim of this study was to determine the effect of educational interventions on improving oral and dental health promotion behaviors in pregnant women.
Electronic search was performed from the beginning of January first 2016 until the end of May 2016 using Persian and English key words from information bank websites (Iran Medex), Scientific Information Database (SID), PubMed, Science direct, Web of Science, and Embase. And, studies in which effects of educational interventions had been investigated were selected.
Most of the studies were of controlled clinical trial using the models and theories of health education and health promotion. Further interventions were in the form of training, examination and instrumental support, and time different.
Health education has a significant influence on improving oral and dental health promotion behaviors in pregnant women. But using theories and models has the feature of specifying the most important factors affecting the issue and then determining a suitable strategy.

Today, acceptance and adaptation to environmental change is essential for all organizations and the style of organization's leadership with other factors has been taken into account in organizational change. Thus, this study aimed to study the relationship between transformational leadership style and commitment to change through the mediation of organizational justice in 2015 among employees of Ardabil University of Medical Sciences.
The research methodology was of descriptive, correlational study (structural equation modeling; SEM) and the population was all the employees of the university. By using the Morgan table, 183 samples were selected by simple random sampling. In order to collect data, transformational leadership questionnaire and commitment to change questionnaire and organizational justice were used. For data analysis, software spss (Pearson correlation and descriptive statistics) and Amos were applied.
The results showed that transformational leadership style had positive and direct and indirect effect on employees` commitment to change through organizational justice. Also, organizational justice directly affected employees` commitment to change.
Nowadays, the change is part of organizational life and the attitude and commitment of staff to these changes and the most important factor is the organizational adaptation to changes. It can be said that the transformational leadership style in organizations and organizational justice can be considered as factors to increase employee' commitment to change.

Databases play a main role in education and research, so academics should be familiar with them and use them optimally. The aim of this study was to investigate the use and awareness of medical multimedia databases in integrated digital library by graduate students at the Hamadan University of Medical Sciences.
The current research is a descriptive survey and data collection tool is questionnaire. 260 people, as sample size, were selected by the stratified randomized sampling technique and finally 200 questionnaires were analyzed. And, the collected data were analyzed by means of descriptive statistics like frequency, frequency distribution, and mean using the SPSS16 software.
The results showed that familiarity rate of 85.1% of the Students with medical multimedia databases were unfavorable and 66.3% of the participants never used the multimedia databases. The most important barrier in using multimedia databases was the lack of notification about existence of the databases (74%).
Most of the graduate students were not familiar with multimedia databases at all and never used them. Considering the results of the current study as well as high costs spent on database subscription, it is necessary to pay more attention to the education and use of the databases by experts.

Acceptance and commitment therapy is a third generation behavior therapy in treatment of mood and anxiety disorders. The purpose of this study was to investigate the effectiveness of acceptance and commitment group therapy on depression and anxiety among women with breast cancer in the Ahvaz city.
In this Quasi-Experimental study with pre-test and post-test, control group, the sample group was selected by available sampling method from women with breast cancer who referred to Golestan hospital, the department of clinical oncology of Ahvaz. All patients had finished their chemotherapy. Thirty patients that have had high depression and anxiety scores with high acceptance and action scores in pre-test qustionnaires were chosen and randomly assigned to two control and experimental groups (each group with 15 subjects). The experimental group experienced the treatment based on commitment and acceptance group therapy and the control group did not receive any treatment. These questionnaires again conducted on both group in post-test.
The results of pre-test, post-test, and follow-up exams showed that the mean depression scores (19.27, 16.13, and 15.53) and the mean anxiety scores (35.20, 29.20, and 28.13) significantly decreased in experimental group compared to the control group respectively. The decrease significantly continued after two-month fallow-up (depression P The results emphasize the importance of using acceptance and commitment therapy in patients with cancer suffering from depression and/or anxiety, and offer new horizons to psychological based clinical interventions in these patients.

Grip and pinch strength are the most important factors affecting the performance of hand and evaluating them as an indicator of activity, illness and performance is important. The aim of this study is to survey the relationship between the use of smart phones with the grip and pinch strength and the pain in students.
350 students (212 female and 138 male) entered the study. The grip and pinch strength including tip, key and palmer pinch of dominant hand was measured 3 times with hydraulic dynamometer and Pinch Gauge. The pain in areas of the upper extremity (shoulder, elbow, forearm, wrist, fingers, thumb and neck) was evaluated with Visual Analog Scale (VAS). Data analysis was performed using SPSS 21 statistical software.
Smartphone use and pain in the thumb, neck, arm, forearm, wrist and fingers relation was not statistically significant (P>0.05). Smartphone use and grip and pinch strength did not show statistically difference as well (P>0.05).
Although result of this study show no relation between smart phone use and grip, pinch and pain in upper limb and neck, but according to previous studies, using the Smartphone will cause muscle fatigue. Also duration of Smartphone use is determinant.

Caffeine is the most widely consumed physiological stimulant which is consumed via natural sources, such as coffee and tea as an energetic drink and dietary supplement. The present study was conducted to identify the effect of different doses of caffeine on time to exhaustion, resting level and cardiovascular responses in male athletes.
Eight male student athletes targeted and were randomly divided into three groups of control, dose of 2.5 mg/ kg caffeine, and dose of 5 mg/ kg caffeine, in a crossover design. Exercise protocol included exhausting running on treadmill (Using Bruce test). Blood pressure (BP), HR and RPP (rate pressure product) was measured before and 1 hour after taking caffeine and immediately after exercise. The data was analyzed using the Shapiro-Wilk, ANOVA with repeated measures (at significance level of 0.05) and Bonferroni post-hoc tests (at significance level of 0.0167).
The data showed that taking both doses of 2.5 mg/ kg and 5 mg/ kg caffeine significantly increased time to exhaustion (P≤0.0167). In addition, dose 5 mg/ kg caffeine significantly Increase systolic blood pressure and RPP at rest, heart rate, systolic blood pressure and RPP at immediately after to exhaustion (P≤0.0167).
It seems that male athletes can increase/improve the time to exhaustion by consuming 2.5 mg/ kg of caffeine supplements without deleterious side effects of cardiovascular instead of 5 mg/ kg 1 hour before exercise. Further researches are necessary, to draw firm conclusions.