Introduction: Hydrogen Peroxide poisoning can cause death. The chemical reactions in the body will produce complications, such as stroke, perforation of the gut, and embolism. These complications are most likely seen with high concentrations. Case Presentation: The patient was a 55-year-old female, who tried to commit suicide by ingestion of approximately 150 cc of hydrogen Peroxide. She was brought to the emergency room for medical treatment. During the physical examination, the patient had air in the neck and mediastinum, which is a strong indication of acute mediastinitis. The patient was treated with esophagectomy and feeding jejunostomy. The pathology reported first degree burns of the esophagus without perforation. The patient underwent reconstructive surgery and treatment for eight weeks, yet she died during surgery as a result of low ejection fraction (EF). Conclusions: In this case, the patient intentionally ingested a low concentration (15%) of hydrogen Peroxide and as a result experienced first degree burns in the esophagus. The patient did not require surgery for treatment. The presence of white mucus and air around the esophagus and stomach was thought to be indicative of acute mediastinitis and mistakenly exposed the patient to major surgery.

Unbleached chemi-mechanical pulp of 85% pulp yield and produced from hornbeam, beech and populus woods respectively by 3: 1: 1 ratio, was used for Peroxide bleaching. Two bleaching systems, alkali Peroxide (conventional bleaching) and activated Peroxide by TAED activator, were used for pulp bleaching. Bleaching treatments included different percentages of hydrogen Peroxide and caustic soda consumption. In this research, the hydrogen Peroxide consumption rate, pulp yield, process selectivity, bleached pulp brightness and bleaching effluent pollution load (COD) were investigated. Results showed that, brightness values were increased by bleach chemicals charge rising, in both bleaching systems, but the increasing trend was downward. Also, pulp yield was decreased by increase of chemical charges, but residual Peroxide was raised. The activated Peroxide process compare to conventional process had lower efficiency and brightness improvement values of pulp were less than those of alkali Peroxide process. But pulp yield and effluent pollution load was less by activated Peroxide bleaching.

Objective: The aim of this study was to determine the effects of 40% hydrogen Peroxide and 15% carbamide Peroxide on microhardness and color change of a silorane-based composite resin in comparison with two methacrylate-based composites.Materials and Methods: Fifty-four disc-shaped specimens (A3 shade) were fabricated of Filtek P90 (P90), Filtek Z350XT Enamel (Z350) and Filtek Z250 (Z250) (3M-ESPE) (n=18). The samples of each composite were randomly divided into three subgroups of 6. The control subgroups were immersed in distilled water; the test groups were exposed to Opalescence Boost (OB) once; and Opalescence PF (OP) (Ultradent) for two weeks. Vickers microhardness testing and a spectrophotometric analysis of the color of samples were performed before and after each intervention.Results: The baseline microhardness of P90 was significantly lower than that of the other two composites (P=0.001), but no difference was found between Z250 and Z350 in this respect (P=0.293). Bleaching treatments significantly decreased the microhardness of Z250 and Z350 (P<0.001), but no change was observed in P90 test and con-trol subgroups (P>0.05). No significant difference was detected between the two types of bleaching (P>0.05). After bleaching with OB, DE value was measured to be 3.12 (1.97), 3.31 (1.84) and 3.7 (2.11) for P90, Z250 and Z350, respectively. These values were 5.98 (2.42), 4.66 (2.85) and 4.90 (2.78) after bleaching with OP with no significant difference.Conclusion: Bleaching decreased the microhardness of methacrylate-based but not silorane-based composites. Although no significant differences were found in DE of composites, DE of all groups did not remain in the clinically acceptable range after bleaching except for P90 after bleaching with 40% H2O2 (E<3.3).

In this contribution, an analytical method was developed utilizing silver nanozymes as inexpensive and high throughput nanomaterials with high peroxidase-like activity for the selective quantification of hydrogen Peroxide in food samples. 3, 3’, 5, 5’-tetramethylbenzidine (TMB) was utilized as peroxidase substrate to produce the blue-colored analytical probe. The method was constructed based on the spectrophotometric probing the oxidation product of TMB by hydrogen Peroxide in the presence of silver nanozyme as catalyst and the absorbance of the blue-colored oxidation product at 658 nm was used as analytical signal. The effective parameters on the method sensitivity including nanozyme amount, incubation time, buffer type and concentration, pH, and substrate concentration were optimized. In optimal experimental conditions, a linear dynamic range of 1-80 μM and detection limit as low as 0. 12 μM were obtained. Besides, the selectivity studies revealed that the absorbance at 658 nm was increased in the presence of hydrogen Peroxide while other co-existing species cannot proceed the oxidation process. Finally, the designed method was applied to quantify hydrogen Peroxide of milk samples, revealing highly accurate results. The results of this research can be potentially utilized for food safety verification in food industries.