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Summary The purpose of this study was to compare the effect of a 4-bracket system including Alexander, Roth, MBT (Maxillary Transverse Bioadaptation), and Gianelly on the upper anterior tooth movement in sliding mechanics with the help of a 3-Dimensional (3D) Finite Element Method. Methods Displacement, stress, strain, centre of rotation and resistance on the incise edge and apex of the maxillary central incisor were calculated when 100, 200, 300, 400 grams of retraction force were applied. Results The amount of incise edge displacement was 2.609 × 10−4 mm 2.682 × 10−4 mm 2.875 × 10−4 mm and 2.881 × 10−4 mm in Alexander, Gianelly, Roth and MBT respectively with 100gr of retraction force. The value of apex root movement was 3.485 × 10−4 mm 3.547 × 10−4 mm 3.852 × 10−4 mm and 3.864 × 10−4 mm in Alexander, Gianelly, Roth and MBT respectively with 400 g of retraction force. Conclusions The MBT system had the maximum apex root and incisal edge movement in all 100, 200, 300, 400 grams of retraction force. The Alexander system had the lowest apex and incisal edge movement in all retraction forces.

Introduction: The main pathogenesis of COVID-19, especially in patients with moderate to severe COVID-19 pneumonia, is through cytokine release syndrome. This cytokine release causes tissue edema, chemotaxis of immune cells, and also vascular endothelial disruption. Thalidomide is an old drug with several effects on inflammation and also on immune cells physiology. Materials and Methods: 50 patients with moderate COVID-19 pneumonia, were included in this study in the Thalidomide group and control group. We administered Thalidomide 100 mg daily for 14 days + Dexamethasone + Remdesivir in the Thalidomide group and Dexamethasone + Remdesivir as the standard of care in our center in the control group. We evaluated oxygen saturation improvement to more than 94% and also the duration of hospital admission and mortality in our study. Results: We did not find any difference between these two groups in terms of duration of hospital stay (8.9 days in the Thalidomide group versus 9.6 in the control group), improvement of oxygen saturation at the first week and second week (Pvalue: 0.70 and 0.826 respectively). There was no mortality in both groups. At the end of second week of treatment, the levels of inflammatory markers were not statistically different between these two groups (ESR, CRP, ferritin, LDH, fibrinogen with Pvalue: 0.509, 0.440, 0.121, 0.005, 0.114 respectively). Only LDH in the Thalidomide group was significantly lower at the end of the second week than the control group. Conclusion: In our study, we did not find any relation between Thalidomide administration and effects on oxygen saturation improvement and also the duration of hospital admission and mortality.

Introduction The purpose of this study was to determine the prevalence of hypodontia, hyperdontia, and impacted teeth in children with various types of clefts. Methods This study sample consisted of 201 cleft patients including 131 male subjects with a mean age of 12.3 ± 4 years and 70 female subjects with a mean age of 12.6 ± 3.9 years. Charts, models, radiographs, and intraoral photographs were used for the study. t tests, chi-square tests, and binomial tests were used for assessment of the data. Results and Conclusions Hypodontia was found in 129 subjects (64.1%). The chi-square test showed no statistically significant difference between the type of cleft and hypodontia (P

This paper presents an experimental study of the charging of low-conductivity liquids by screens. Measurements were performed over a wide range of fluid conductivities and screen types. The relationship that was obtained between the current generated and the velocity of the fluid closely matched the theory. Potential measurements across the screen indicated that the charging process can be characterized by a charging electromotive force.

This paper presents a theory for the electric charging process which occurs when low-conductivity fluids pass through a screen. It is shown that the process can be characterized by a charging electromotive force. Explicit analytic expression are derived for the charging current for a wide range of flow rates and fluid conductivities.