---

 
Background & objectives: Third molar impaction (wisdom tooth) is a widespread phenomenon. It is indeed very important to study the impacted teeth pattern in the community since it will help to develop an appropriate treatment plan for individuals of the community. The aim of this study was to investigate the impaction pattern of mandibular third molar in Ardabil population.
Methods: In this study, the panoramic radiography of 382 patients referred to the Ardabil Dental Clinic, ranging 18-40 years old that had a couple of third molar teeth were investigated. The radiographs were investigated to collect data corresponding to depth-of-impaction, the distance between the canal and inferior alveolar, number of roots, shape and connection between the roots as well as the damages to neighboring structure. The collected data were coded to be analyzed through Chi-square and t- test in SPSS software.
Results: Among the cases, 42.4% and 57.6% of the subjects were male and female respectively. There is no significant difference between men and women for number of roots and the connection between them, whereas noticeable differences between men and women were observed for depth of impaction, distance from Inferior alveolar canal, the shape of the roots and damage to neighboring structures.
Conclusion: The results suggest that most of the cases had vertical angulation, regarding depth of impaction, most of the teeth were categorized in Class-B, regarding distance from Inferior alveolar, and most of the cases were in the vicinity of the canal and had two separate canals. Regarding damage to neighboring structures, most of the cases were categorized as a radiographic bone loss

---

Background & objectives: Mitochondrial dysfunction is one of the main risk factors for neurological diseases which are associated with aging. On the other hand, aerobic exercise has beneficial effects on the brain health and cognitive function, and also improves mitochondrial dynamics. Therefore, the aim of the present study was to investigate the effect of 4 weeks of aerobic exercise on spatial learning, memory performance and mitochondrial dynamics in the hippocampal tissue of old rats.
Methods: For this purpose, 14 male Wistar rats at 20 months of age were randomly divided into 2 groups: aerobic exercise (n=7) and control group (n=7). The exercise group performed 4 weeks of treadmill training (5 days per week at a speed of 10 to 15 m/min). Forty-eight hours after the last training session, the animals underwent behavioral tests. Twenty-four hours after the behavioral test, all rats were killed and hippocampal tissue was extracted. The mRNA expression of OPA1, Mfn2 and Drp1 genes were assayed using Real Time-PCR. The Independent t test was used for statistical analysis.
Conclusion: Aerobic exercise in old animals improved spatial learning and memory performance, increased hippocampal OPA1 gene expression, and decreased Drp1 gene expression compared to the control group (p≤0.01).
Conclusion: It seems that aerobic exercise can improve the function of brain mitochondria by modulating fusion and fission processes and it can be considered as an effective non-pharmacological method to deal with aging-related learning and memory perturbations.

---

Background& objectives: Renal ischemia-reperfusion (IR) damage occurs during renal transplantation in end-stage renal disease (ESRD) patients which activate immune responses. Inflammatory responses by increased levels of cytokines can lead to acute kidney injury (AKI) that contributes to the loss of renal grafts and graft dysfunction. The purpose of this study was to review the therapeutic effects of nanoparticles in AKI.
Methods: A comprehensive search strategy was identified relevant studies on AKI models, using the Scopus, PubMed and Google Scholar databases, from 2000 until 2020. The search strategy included keywords like ischemia-reperfusion and nanoparticles.
Results: Oxygen free radicals are produced during the reperfusion phase, which cause lipid peroxidation and promote tissue damage. Oxidative damage to DNA and proteins and lipid membrane peroxidation can cause cell death and apoptosis. Some strategies to reduce the tissue damage caused by ischemia-reperfusion are nanoscale materials. Antioxidant nanoparticles reduce oxidative stress in tissues. Also, they have flexibility in the delivery of therapeutic agents and drugs to the ischemic cells, and imaging of the ischemic regions at the molecular or cellular level.
Conclusion: This potential of antioxidant and anti-inflammatory nanoparticles in the diagnosis and treatment of renal ischemic regions is an innovation in the development of new therapies and a unique achievement in recent medical advances.