---

Background and purpose: Previous researches indicated a relationship between impulsivity and Internet addiction. This study was conducted to compere the symptoms of attention deficit-hyperactivity disorder (ADHD) in Internet addicted and non-addicted university students.

Materials and methods: This comparatevi study was performed in 311 individuals who were selected by convenience sampling. Data was collected using the Young’s Internet addiction test and Conners' Adult ADHD Rating Scales (CAARS). Data was analysed applying ANOVA in SPSS V.16.

Results: The results showed higher scores of ADHD in Internet-addict students compared with students not addicted to Internet (P=0.001).

Conclusion: Current results are consistent with previous findings proving that individuals addicted to Internet have more ADHD symptoms than those not addicted to Internet.

---

Background and purpose: Various contaminants are released into water resources each year as a results of urbanization and industrialization. Chromium VI is one of the most toxic metals released into the aquatic environments, wastewater, and soil mainly via industrial sewage. The purpose of this study was to evaluate the performance of iron-zirconium/chitosan magnetic nanoparticles composite in removal of hexavalent chromium VI from aquatic environments.

Materials and methods: A pilot-study was conducted in laboratory scale. Nancomposites synthesis was done using chemical precipitation and tested by SEM, XRD, and FTIR. Various factors such as contact time (0-720 min), initial pH of the solution (2-12), adsorbent dose (0.4-2 gr), initial concentration of metal (0-10 milligrams per liter), and the system temperature (15-35 ℃) were studied. The concentration of heavy metal chromium was measured using a spectrophotometer at 540nm.

Results: The results showed that the highest removal efficiency of heavy metal chromium was obtained at pH 4.0 (52.99%). Moreover, addition of 1 gr composite in the same concentration could boost removing the hexavalent chromium by more than 91%. Increasing the concentration levels of heavy metals had little impact on the removal efficiency. Adsorption isotherms fitted the Freundlich isotherm.

Conclusion: According to the results, the absorbent showed a high performance in removing chromium VI from aquatic environments.

---

Background and purpose: With increase in human population the demand for meat products has raised. One of such products is poultry meat which could be contaminated by heavy metals in production process. The purpose of this study was to estimate the concentration levels of cadmium, lead, and zinc in chicken tissues consumed in Sanandaj, Iran, 2016.

Materials and methods: In this cross-sectional study, twenty samples of liver, thigh and pectoral muscle were collected from chickens. The samples were digested by acid method and concentrations of Cd, Pb and Zn were measured using atomic absorption spectrophotometer.

Results: The liver and pectoral muscle of chickens had the highest and lowest concentrations of Cd, Pb and Zn, respectively. Zn and Pb were found to have the most and least concentrations, respectively. Daily and weekly intake of heavy metals in edible tissues showed that the estimated amount of metals intake is lower than the maximum acceptable level permitted by the joint FAO/WHO expert committee.

Conclusion: The present study showed that chicken meat in Sanandaj is safe to consume and does not threaten the health of consumers.

---

Background and purpose: Fish is consumed by humans for its nutritional properties, but accumulation of heavy metals in fish can pose serious health hazards. The aim of this research was to investigate the concentration of heavy metals in the muscle and liver of common carp in Zarivar wetland, Iran.

Materials and methods: A cross-sectional study was conducted in which carps were caught from Zarivar Wetland in 2015. The levels of heavy metals in liver and muscle were measured using ICP.

Results: The findings indicated that Fe and Pb in liver, and Zn and Cd in muscle had the highest and lowest concentrations, respectively. The levels of heavy metals in liver were higher than those in the muscles of carp. Moreover, the Target Hazard Quotients for an adult person with mean weight of 71.5 kg was lower than 1 for the levels of heavy metals studied (expect for Cr).

Conclusion: This research showed that the levels of heavy metals in edible muscle of carp was lower than international standards, but according to the bioaccumulation and toxicity of these metals in humans periodic monitoring is required.

---

Background and purpose: Southern area of the Caspian Sea is an important resource of seafood products in Iran. One of the major factors affecting the health of seafood consumers is lead (Pb), due to its wide distribution and bio-accumulative property. In this study, all the studies, conducted during 2003-2016 on the amount of lead in white, mullet, and carp fish at the southeastern coast of the Caspian Sea were assessed.

Materials and methods: This meta-analysis used the data on 1242 muscle tissues of Rutilus frisii kutum, Liza auratus, Liza saliens, and Cyprinus carpio collected from the southern coast of the Caspian Sea. The level of lead concentration in samples was obtained from recently published articles in valid scientific journals. Then, dietary consumption risk and consumption limit of these fishes were assessed.

Results: In this study, mean concentrations of lead in fish muscle tissues were higher compared to levels accepted by various various national. However, daily and weekly absorption of this element through fish consumption was lower than the dose permitted by the Food and Agriculture Organization/World Health Organization. It was found that 0.23, 0.43, and 0.28 kg/day of Caspian white fish, mullet, and carp for adults, and 0.048, 0.09, and 0.58 kg/day of the these fishes can be consumed by children, respectively, without any non-carcinogenic effects.

Conclusion: According to the results of this study, a great difference was observed between various studies in terms of the reported effect factor. While publication bias was notable, it seems that the current amount of consumption of the evaluated fish has led to no serious health risks in consumers.

---

Background and purpose: Toxoplasma gondii (T. gondii) is an obligatory intracellular protozoan parasite. Toxoplasmosis is highly prevalent and has a great effect on public health, therefor, there is a need for vaccine and sensitive diagnostic procedures. This study aimed at cloning and investigating the expression of ROP13 gene of T. gondii.
Materials and methods: In this study, the gene was cloned in pTG19-T vector and transferred to a TOP10 strain of E.coli following ROP13 gene amplification using PCR. Then the ROP13 gene was sub cloned in expression plasmid pcDNA3. Also, pcROP13 was transferred to CHO cells and the expression level was evaluated by IFA method.
Results: Cloning and sub cloning of ROP 13 gene were confirmed by PCR, sequencing and enzymatic digestion. The gene sequencing showed complete homology with a recorded sequence in the gene bank. Moreover, the expression of ROP13 gene in CHO eukaryotic cells was confirmed by IFA method.
Conclusion: The results showed that ROP13 gene was successfully sub cloned into the pcDNA3 expression vector and expressed in CHO cells. Therefore, it can be used in the development of vaccines and in diagnostic tests.

 

---

Background and purpose: Nitrous oxide (N2O) is an anesthetic widely used in operating rooms. Chronic exposure to N2O causes decrease in mental performance, peripheral neuropathy, and polyneuropathy. The aim of this study was to compare neurological complications caused by N2O exposure between operating room staff and other hospital staff.
Materials and methods: In this multicenter cohort study, operating room staff (n=110) and non-operating room staff (n= 224) in Arak Valiasr Hospital and Isfahan Al-zahra Hospital were randomly selected and individually matched. Both groups were examined for neuropathic symptoms and their medical history was recorded. Clinical neurological exams such as Romberg test were used in both groups. Patients with neuropathic sign and symptoms were referred to a neurology clinic to confirm any diagnosis.
Results: The two groups were significantly different in ataxia, numbness, weakness and paresthesia of upper and lower limb, Romberg test score, and levels of Vitamin B12 (P<0.05). No significant differences were observed between the two groups in mean Hemoglobin level, temperature sense, touch and two-point discrimination, stereo gnosis, tandem walking, and plantar and dorsal flexion (P≥ 0.05).
Conclusion: Chronic exposure to nitrous oxide was found to decrease serum vitamin B12 levels and caused neurological symptoms and complications. Therefore, clinical and laboratory evaluations and monitoring of exposure to nitrous oxide is necessary.
 

---

Background and purpose: A lot of research has been done on the effectiveness of rehabilitation treatment in children with cerebral palsy. Functional mobility is one of the significant aspects in treatment of these children. This systematic meta-analysis aimed at reviewing the studies on the effectiveness of task oriented training on functional mobility in children with cerebral palsy.
Materials and methods: All articles about the effectiveness of task oriented training for functional mobility in children with cerebral palsy in English or Persian, published until January 2020, were studied by a thorough search in electronic databases, including  Medline, Embase, CINAHL, PubMed, PsychInfo, Web of Science, Magiran, ISC, and SID. After screening and assessing the quality of research papers and applying inclusion and exclusion criteria, data was analyzed by Comprehensive meta-analysis software (CMA).
Results: Out of 345 articles, eight met the inclusion criteria. The meta-analysis showed that task oriented training had more significant effect on functional mobility than other conventional approaches in children with cerebral palsy (P=0.000).
Conclusion: Task oriented approach could be used as a treatment method in improving functional mobility in children with cerebral palsy.