Preliminary Evaluation of Gunshot Residue (GSR) Using 3-Aminophenol as a Substitute in Modified Griess Test

In forensic ballistics, gunshot residue (GSR) particles can be detected using screening or presumptive tests which are mainly focused on the chromophoric reaction. Most tests serve as an initial indication for a forensic investigator at the crime scene before instrumental analysis for definitive identification. The screening methods are known to be convenient, have fast analysis, and minimal preparation. In GSR analysis, the well-known method of detecting GSR known as the Modified Griess Test (MGT) requires acid and heat for the reaction. Therefore, this study demonstrated a new and rapid screening test named the Rapid Griess Test (RGT) for the detection of GSR. This study intends to improve the functionality of previous screening reagents in determining nitrite (NO2–), the composition present after shooting activity. To do this, chemical reagents with an amino group, 3-aminophenol, were substituted with alpha-naphthol. The experiment showed that the reactions were positive color changes using standard NO2– and real GSR samples. The diazotization reactions involving sulfanilic acid and 3-aminophenol produced azo dyes that changed the solution from colorless to orange in the presence of NO2–. The RGT reagent will make it possible to avoid using heat and the addition of acetic acids in a sample to form chromophoric reactions. Moreover, the colorimetric method using Video Spectral Comparator (VSC) showed that RGT had higher intensity of the orange color when compared to MGT.

The role of nitric oxide in the development of gastroesophageal reflux disease against the backdrop of obesity

Today gastroesophageal reflux disease (GERD) occupies a leading position among chronic diseases of the gastrointestinal tract. The prevalence of GERD in people with normal BMI ranges from 15 to 20%, with obesity – from 50% to 100%. The basis of GERD is a violation of the motor – evacuation function of the gastroesophageal zone, which is accompanied by a steady relaxation of the antireflux barrier. Nitric oxide (NO) plays an important role in this process. The aim of this work is to study the level of nitric oxide in patients with gastroesophageal reflux disease on the background of obesity and to assess its impact on the course of the disease. Materials and methods. The study involved 80 young people. Questionnaire was conducted using the GERDQ questionnaire, BMI, serum nitric oxide level by Griss spectrophotometric method with sulfanilic acid and 1-naphthylamine, FGDS to determine the severity of reflux esophagitis. Study participants were divided into 3 groups: patients with GERD with concomitant obesity, patients with GERD without concomitant pathology, the control group, which consisted of almost healthy individuals. Analyzing the obtained results, a significant increase in the concentration of nitric oxide in the blood of patients with GERD with concomitant obesity, compared with patients with GERD without concomitant pathology and the control group. There is a direct correlation between the level of nitric oxide in the blood and the severity of reflux esophagitis in patients with GERD with concomitant obesity. Further study of the role of nitric oxide in the pathogenesis of comorbid GERD and obesity will contribute to the development of improved methods for diagnosis, treatment and prediction of disorders.

Sunlight-Driven AO7 Degradation with Perovskites (La,Ba)(Fe,Ti)O3 as Heterogeneous Photocatalysts

Perovskites of the (La,Ba)(Fe,Ti)O3 family were prepared, characterized, and utilized as heterogeneous photocatalysts, activated by natural sunlight, for environmental remediation of Acid Orange 7 (AO7) aqueous solutions. Catalysts were prepared by the ceramic (CM) and the complex polymerization (CP) methods and characterized by XRD, SEM, EDS, and band gap energy. It was found that catalytic properties depend on the synthesis method and annealing conditions. In the photocatalytic assays with sunlight, different AO7 initial concentrations and perovskite amounts were tested. During photocatalytic assays, AO7 and degradation products concentrations were followed by HPLC. Only photocatalysis with BaFeO3-CM and BaTiO3-CP presented AO7 removals higher than that observed for photolysis. However, photolysis leads to the formation of almost exclusively amino-naphthol and sulfanilic acid, whereas some of the perovskites utilized form less-toxic compounds as degradation products, such as carboxylic acids (CA). Partial substitution of Ba by La in BaTiO3-CM does not produce any change in the photocatalytic properties, but the replacement of Ti by Fe in the La0.1Ba0.9TiO3 leads to reduced AO7 removal rate, but with the formation of CAs. The best AO7 removal (92%) was obtained with BaFeO3-CM (750 mg L−1), after 4 h of photocatalytic degradation with solar radiation.