Conclusion Ovariectomy improved metabolic and oxidative stress markers in a rat model of PCOS.Although gamete cryopreservation has facilitated advancement of reproduction research by allowing the storage of cells over prolonged periods of time, during freezing-thawing cycles, cells inevitably suffer from cryoinjuries. Here, we evaluate oxidative stress and DNA damage of zebrafish sperm at different stages of the cryopreservation process. It was generally observed that the freezing and thawing of the samples led to an increase in the generation of reactive oxygen species and the activity of the catalase enzyme and a reduction in the generation of sulfhydryl groups and superoxide dismutase activity. The alkaline comet assay demonstrated that DNA damage increased after equilibration time, with an even greater increase after freezing and thawing. The comet assay modified with the enzyme formamidopyrimidine glycosylase, and Endonuclease III demonstrated greater DNA damage than the standard comet assay, demonstrating a high degree of oxidation of purines and pyrimidines at all stages of cryopreservation. Our results show that the freeze and thaw processes cause greater oxidative stress and DNA damage than cryoprotectant toxicity during exposure at the equilibrium stage.Background Reconstruction of nasal skin defects can be challenging due to limited skin laxity and underlying cartilage and, therefore, often require a complex repair. The aim of this review is to systematically analyze the literature on nasal skin reconstructions with specific detail to flap reconstructions. Methods A systematic literature review of nasal skin reconstruction was performed and focused on flap reconstructions. Flap reconstructions were stratified based on defect size, nasal subunit, and reconstruction type. Complication rates (CRs) and patient outcomes were also assessed. Results A total of 176 articles (11,370 patients) met the inclusion criteria. Of these, 59 articles showed various flap techniques. For defects ≤1.5 cm, every subunit had four to six options except the alar rim, which showed one option. Rotation-advancement flaps were mostly used for the nasal tip and sidewall, whereas bilobed flaps were used more for the ala and dorsum. Defects >1.5 cm were most commonly reconstructed with the forehead flap. The mean CR of flap reconstructions was 13.8%. Only 8 of the 176 articles (4.5%) reported patient satisfaction using a standardized questionnaire. Conclusion This review shows various flap reconstruction options with their corresponding CR that will help guide the surgeon in choosing reconstructive options for different nasal skin defects.Background Impassable caustic esophageal strictures (CES) can be rendered passable through sophisticated dilatation techniques, hence avoiding the esophageal replacement surgery and its complications. Patients and Method Patients with impassable CES who were presented to our hospital between January 2015 and April 2020 underwent a combined balloon and bougie dilatation. This technique aims at doing an initial partial dilatation of the proximal segment of the stricture, using a balloon catheter to pave the way for the endoscope to be advanced more distally. Therefore, a guide wire could be passed down to the stomach to complete the dilatation session using bougie dilators. Results Seven patients out of 138 patients who underwent endoscopic dilatation for CES at the pediatric surgery department were enrolled in this study. Their ages ranged from 2.5 to 6 years. This technique was successful in 6 patients indicating technique reproducibility of 85.7%. These 6 patients continued their next dilatation sessions using bougie dilator only, whereas 4 patients were completely cured from dysphagia indicating technique efficiency of 57%, 1 is still on dilatation, and 1 patient had a resistant stricture. learn more The dilatation through the proposed technique failed in 1 patient, who was referred for a replacement surgery. Conclusion Combined dilatation is safe and effective to preserve the native esophagus in some difficult CES.The preservation of DNA in biological samples is important for forensic testing, as samples can be tested years or even decades after collection. Generally, the DNA within biological evidence is stable over shorter time frames but can degrade over extended periods. In this work, we evaluated accelerated aging as a method to reduce the duration of studies examining the stability of DNA in forensic evidence-type samples. Evaluation of the DNA extracted from cells stored at 37 and 50°C for 194 or 79 days, respectively, showed similar quality metrics to cells stored at 25°C for 548 days.Pyridoazepinones are potentially interesting structures, yet they are still underexploited in the medicinal chemistry field and hard to obtain synthetically. We present a general and flexible synthetic route to substituted pyridoazepinones, enabled by the xanthate addition-transfer process, which furnishes the target molecules from readily available starting materials in generally good yields. The method shows good functional group tolerance and allows the preparation of pyridoazepinone scaffolds on gram scale.Katritzky salts have emerged as effective alkyl radical sources upon metal- or photocatalysis. These are typically prepared from the corresponding triarylpyrylium ions, in turn an important class of photocatalysts for small molecules synthesis and photopolymerization. Here, a flow method for the rapid synthesis of both pyrylium and Katrizky salts in a telescoped fashion is reported. Moreover, several pyrylium salts were tested in the photoinduced RAFT polymerization of vinyl ethers under flow and batch conditions.The enantioselective reaction of 2H-azirines with oxazol-5-(4H)-ones (oxazolones) using a cinchona alkaloid sulfonamide catalyst has been developed. The reaction proceeded at the C-2 position of oxazolones to afford products with consecutive tetrasubstituted stereogenic centers in high yield with high diastereo- and enantioselectivity. The obtained aziridines were converted into various chiral compounds without loss of enantiopurity.