A novel ACE2-Based electrochemical biosensor for sensitive detection of SARS-CoV-2.

SARS-CoV-2 emerged in late 2019 and quickly spread globally, resulting in significant morbidity, mortality, and socio-economic disruptions. As of now, collaborative global efforts in vaccination and the advent of novel diagnostic tools have considerably curbed the spread and impact of the virus in many regions. Despite this progress, the demand remains for low-cost, accurate, rapid and scalable diagnostic tools to reduce the influence of SARS-CoV-2. Herein, the angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2, was immobilized on two types of electrodes, a screen-printed gold electrode (SPGE) and a screen-printed carbon electrode (SPCE), to develop electrochemical biosensors for detecting SARS-CoV-2 with high sensitivity and selectivity. This was achieved by using 1H, 1H, 2H, 2H-perfluorodecanethiol (PFDT) and aryl diazonium salt serving as linkers for SPGEs and SPCEs, respectively. Once SARS-CoV-2 was anchored onto the ACE2, the interaction of the virus with the redox probe was analyzed using electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). Aryl diazonium salt was observed as a superior linker compared to PFDT due to its consistent performance in the modification of the SPCEs and effective ACE2 enzyme immobilization. A distinct pair of redox peaks in the cyclic voltammogram of the biosensor modified with aryl diazonium salt highlighted the redox reaction between the functional groups of SARS-CoV-2 and the redox probe. The sensor presented a linear relationship between the redox response and the logarithm of SARS-CoV-2 concentration, with a detection limit of 1.02 × 106 TCID50/mL (50% tissue culture infectious dose). Furthermore, the biosensor showed remarkable selectivity towards SARS-CoV-2 over H1N1virus.

Fournier's gangrene mortality: A 17-year systematic review and meta-analysis.

BACKGROUND: To provide better management of Fournier's gangrene, mortality-associated comorbidities and common etiologies were identified. METHODS: A systematic search was conducted using 12 databases, followed by meticulous screening to select relevant articles. Meta-analysis and meta-regression (for possible cofounders) were both done for all possible outcomes. RESULTS: Out of 1186 reports screened, 38 studies were finally included in the systematic review and meta-analysis. A higher risk of mortality was detected in patients with diabetes, heart disease, renal failure, and kidney disease, with risk ratios (RR) and 95% confidence intervals (95% CI) of 0.72 (0.59-0.89), 0.39 (0.24-0.62), 0.41 (0.27-0.63), and 0.34 (95% CI 0.16-0.73), respectively. However, there was no association between mortality rates and comorbid hypertension, lung disease, liver disease, or malignant disease (p > 0.05). The highest mortality rates were due to sepsis (76%) and multiple organ failure (66%), followed by respiratory (19.4%), renal (18%), cardiovascular (15.7%), and hepatic (5%) mortality. CONCLUSIONS: Modifications to the Fournier's Gangrene Severity Index (FGSI) are recommended, in order to include comorbidities as an important prognostic tool for FG mortality. Close monitoring of the patients, with special interest given to the main causes of mortality, is an essential element of the management process.