Heroism

Berlin Prize 2020 Honorable Mention Winning Submissio

The Effect of Bleaching Agents on the Microstructure and Surface Microhardness of Three Calcium Silicate-based Barrier Materials

Introduction: The aim of this study was to evaluate the effects of exposure to sodium perborate and H2O2 on the surface characteristics of MTA Angelus, Biodentine and MTA Repair HP after 1 and 6 month time intervals. Methods and Materials: Three calcium silicate-based cements were evaluated: MTA Angelus, Biodentine, MTA Repair HP. A total of 234 specimens were stored in Hank’s balanced salt solution (HBSS) for 1 month or 6 months in which afterwards were divided into 3 groups according to bleaching agent applied: control, sodium perborate, 35% hydrogen peroxide. The microstructural changes were evaluated by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The surface microhardness was also evaluated. Data were analyzed by one-way analysis of variance and Games-Howell post-hoc tests for the effect bleaching agents and hydraulic calcium silicate-based cements and t-test was for the effect of time. Results: Distinctive alterations with uneven depression areas, woodpecker defects and cracks were seen due to exposure to perborate and H2O2 on all evaluated cements. Exposure to H2O2 caused a decrease in Ca/Si ratio in all experimental cements. Both H2O2 and perborate significantly decreased the microhardness of all cement (P<0.05) with H2O2 having a more profound effect (P<0.01). A 6-month delay in exposure to bleaching agents significantly increased the microhardness of Biodentine compared to 1 month (P<0.001 for both bleaching agents). Conclusion: Based on this in vitro study, H2O2 had more detrimental effects on MTA Angelus, Biodentine and MTA Repair HP. Sodium perborate may be a more conservative selection when considering effects on barrier materials.Keywords: Bleaching Agent; Calcium Silicate Cement; Microhardness; Mineral Trioxide Aggregate; Scanning Electron Microscop

Comparison of 1 versus 3 Days Post-operative Catheterization after Anterior Colporrhaphy

With attention to the fact that after anterior colporrhaphy surgery and stitches on vaginal mucus, inserting urinary catheter is requested, according to scientific references and in order to prevent from urinary retention, it has been said that the catheter should be inserted for 3 days. But inserting the catheter leads to infections of bladder and pain. So, in the present study, we compared the removal of the catheter 24 hours versus 72 hours after the surgery, considering urinary infections, urinary retention, patient’s ease and hospitalization. Within two groups of 70 patients, which has been assimilated based on basic factors (devided into two groups accidently with excel table) urinary catheter fixed for 1 and 3 days. After that, patients were compared considering urinary retention, urinary infections and the rate of patient satisfaction. Urinary retention was 28.6% in the test group and 22.9% in a controlling group which was not statistically meaningful (P=0.78). Urinary infections were 22.9% in the test group and 34.3% in the controlling group (P=0.42) and the rate of patient’ssatisfactions was 57.1% in the test group and 40% in controlling group (P=0.23). The hospitalization period in the test group and in the control group was 2.91±0.61 and 3.94± 0.59 days respectively with a significant difference (P=0.001). The results showed that short time catheterization is more satisfactory in comparison long catheterizations

Prevalence of cagA, cagT, cagE, vacA and hrgA genes in Helicobacter pylori strains isolated from patients with gastric cancer in Karaj city, 2016

Background: It is estimated that approximately half of the planet's population is infected with Helicobacter pylori and 70-60 of the infections in the Western countries are caused by cagA-positive strains. The aim of this study was to determine the frequency of cagA, cagT, cagE, vacA and hrgA genes in H. pylori isolated from patients with gastric cancer. Materials and Methods: A total of 50 non-repetitive biopsy samples were collected from patients undergoing endoscopy in the endoscopic center of the Shahid Fayaz Hospital in Karaj. The presence of cagA, cagT, cagE, vacA and hrgA genes was determined using the multiplex PCR method. Results: Of the 50 gastric biopsies, 44 samples (88) were positive for the presence of various virulence genes. The molecular analysis of virulence factors showed that the prevalence rates of cagA, cagT, cagE, vacA and hrgA genes were 16 (32), 8 (16), 13 (26), 7 (14) and 17 (34), respectively. There was a significant relationship between sex, smoking and gastric ulcer with some genes, but no significant relationship was found between the family history and age group with any of the genes. Conclusion: The presence of various pathogenic genes has a significant effect on gastric ulcer, duodenal ulcer and gastric cancer. The effects of other genes, such as hrgA, are important in tissue damage and inflammatory responses

Introduction of RNA virus evolution

Lots of viruses, in particular RNA viruses, have high mutation rates and relatively short generation times. Particle stability during infection in nature or in laboratory triggers the evolutionary event toward different mechanisms such as genome segmentation, point mutation and  recombination. The frequency of mutant genomes increase and modify  the previous distribution, which, consequently, lead to emergence of a new infectious particle. Mutation and selection are the most fundamental processes in evolution. High mutation rate of RNA viruses has an important role in viral fitness. Therefore, it increase our understanding about molecular biology of viral infections and their evolution by selection, mutation could reliably  determine our ability to challenge destructive viruses. This review focuses on existing impressions of genetic organization and mechanisms of RNA viruses evolution

A Study of Hegelian Dialectical Embodiment in “Nostromo” written by Joseph Conrad

The present study investigates Hegel’s theory of dialectic consisting of thesis, antithesis and synthesis, considering social, political and moral concerns in the well known novel written by Joseph Conrad, namely Nostromo. Using Dialectic theory, the famous theory of George Wilhelm Friedrich Hegel, the German philosopher, the novel is evaluated in terms of the Dialectical features. In general, Conrad’s Nostromo novel is investigated here since it is deeply suspected to be closely associated with Dialectic and Hegel’s Dialectic theory based on which, everything is transient and finite, existing in the medium of time; everything is composed of contradictions (opposing forces); gradual changes lead to crises, turning points when one force overcomes its opponent force (quantitative change leads to qualitative change); and finally, change is helical (spiral), not circular (negation of the negation).

A Study of Hegelian Dialectical Embodiment in “Nostromo” written by Joseph Conrad

The present study investigates Hegel’s theory of dialectic consisting of thesis, antithesis and synthesis, considering social, political and moral concerns in the well known novel written by Joseph Conrad, namely Nostromo. Using Dialectic theory, the famous theory of George Wilhelm Friedrich Hegel, the German philosopher, the novel is evaluated in terms of the Dialectical features. In general, Conrad’s Nostromo novel is investigated here since it is deeply suspected to be closely associated with Dialectic and Hegel’s Dialectic theory based on which, everything is transient and finite, existing in the medium of time; everything is composed of contradictions (opposing forces); gradual changes lead to crises, turning points when one force overcomes its opponent force (quantitative change leads to qualitative change); and finally, change is helical (spiral), not circular (negation of the negation).

Life cycle assessment of novel biomethane systems

Climate mitigation and supply of renewable energy are global challenges. The main cause of climate change is anthropogenic activities, including consumption of fossil energy sources and land use change. Biomethane, a biomass-derived renewable energy carrier, is interchangeable with fossil-based natural gas and can provide energy services (e.g. heat, electricity and vehicle fuel) and high-value products such as chemicals. However, the availability of feedstock suitable for anaerobic digestion, the limited grid infrastructure in certain regions and problems relating to storage and distribution are barriers to increased deployment of biomethane systems. This thesis aims to provide decision support for the development and implementation of future biomethane systems, by describing the energy performance and climate impact of some promising novel technologies related to biomethane production, conversion of biomethane to high-value products and biomethane distribution in a life cycle perspective. Anaerobic digestion of maize and pyrolysis of willow for production of biomethane were assessed and compared, while gas-to-liquid (GTL) technologies were studied as potential routes for conversion of biomethane to liquid transportation fuels or platform chemicals. Gas hydrates were assessed as a means of biomethane distribution. The results showed that transition from maize-based anaerobic digestion to willowbased pyrolysis for biomethane production improved energy performance (higher external energy ratio) and environmental performance (lower climate impact), mainly due to buildup of soil organic carbon and use of biochar as a soil amendment or as an energy source to replace fossil coal. Use of biomethane for production of dimethyl ether as a GTL fuel was competitive relative to the conventional compressed biomethane system regarding energy performance and climate impact. Formation and disassociation of gas hydrates was associated with high energy use, and thus technological development is required to overcome the high primary energy inputs and related high climate impact of gas hydrate distribution

Dosage Optimization for Letrozole Treatment in Clomiphene-Resistant Patients with Polycystic Ovary Syndrome: A Prospective Interventional Study

Objective. Dose adjustment for induction of ovulation is one of the most important problem. Methods. In a prospective interventional study, 44 clomiphene-resistant infertile patients (113 cycles) were selected from the Abolfazl Infertility Clinic of Bushehr University of Medical Sciences. Letrozole was given orally in a dose of 2.5 mg, 5 mg, and 7.5 mg, respectively. If the patient displayed no response, the dosage was increased. Results. In this patients ovulation occurred in 50 cycles (44.24%), clinical pregnancy rate according to number of cycles was 23.89% (27 of 113 cycles) and according to the number of patients was 61.36% (27 of 44 patients). In the 2.5, 5, and 7.5 groups, follicles occurred in 22.9%, 42.1%, and 85.18% of cycles, and pregnancy rate was 14.58%, 28.94% and, 33.33%, respectively. Conclusions. It is better to administer Letrozole at a lower dosage to prevent complications and increase the dose based on sonographic results antral follicular count, anti-Müllerian hormone, LH/FSH, and estradiol