Low-energy electron distributions from the photoionization of liquid water: a sensitive test of electron mean-free paths

The availability of accurate mean-free paths for slow electrons ($<$ 50~eV) in water is central to the understanding of many electron-driven processes in aqueous solutions, but their determination poses major...

Eales’ Disease: When the Rare Sounds Frequent

Eales’ disease is a peripheral occlusive retinal phlebitis, with an unclear pathogenesis. The classic association with hypersensitivity to Mycobacterium tuberculosis protein infers that immunologic disturbance may be involved. Here, we described three cases of Eales’ disease. All patients are Caucasian men aged 27-58 years and presented with vitreous hemorrhage and/or peripheral venous vasculitis. Tuberculin skin sensitive test (Mantoux screening test) and interferon-gamma release assay (IGRA) were positive in all patients. Therapeutic approach included antituberculosis therapy and systemic steroids, associated or not to immunosuppressive therapy, and retinal scatter photocoagulation in all cases. Antivascular endothelial grow factor (VEGF) intravitreal injections were also required in two cases. Since various retinal diseases can resemble this presentation, Eales’ disease is considered a diagnosis of exclusion. Early diagnosis and appropriate therapeutic approach are both essential to accomplish disease control and reduce ophthalmologic complications.

Diagnostic significance of detecting neutralizing antibodies to SARS-CoV-2

Coronavirus disease is an infectious disease caused by a recently discovered coronavirus called SARS-CoV-2. Coronavirus disease caused by the SARS-CoV-2 continues to be the world’s greatest global challenge, both in terms of searching for treatment and prevention methods, and developing new diagnostic directions. One of the new directions of serological diagnosis is the possibility of determining neutralizing antibodies to SARS-CoV-2. This is a fully automated highly sensitive test for detecting neutralizing antibo­dies to RBD domain in S1, which is performed by immunochemiluminescent analysis and allows the simultaneous detection of total neutralizing antibodies (IgM + IgG) that increases the sensitivity of testing because the order of IgM and IgG antibodies is individual.

The use of procalcitonin in patients with surgical forms of erysipelas

The ideal marker of bacterial infection should not only allow for early diagnosis, but also provide information about the course and prognosis of the disease. Nowadays the most well-studied and widely used in clinical practice is procalcitonin (PCT), but its value in surgical forms of erysipelas is insufficiently defined. The aim of the article is to determine the diagnostic and prognostic significance of procalcitonin in patients with surgical forms of erysipelas.114 case histories of patients who were hospitalized in the center of purulent-septic surgery of the Non-profit municipal enterprise "City Hospital №3" in Zaporozhye for 2019-2020 period were analyzed retrospectively and prospectively. It was found that most often the focus was localized on the lower extremities. In the complex treatment of patients with erysipelas, the main place belongs to antibiotic therapy (ABT) and early surgical treatment of the area of the pathological process. Determination of the level of procalcitonin in the serum makes it possible to assess the progression and generalization of the process and is a sensitive test for the effectiveness of treatment.Radical surgery and timely targeted ABT are key elements of success in the treatment of surgical forms of erysipelas and are not subject to revision. Procalcitonin is a diagnostic marker that can predict the development of sepsis.

Comparative Performance Testing of Respirator versus Surgical Mask Using a Water Droplet Spray Model

Background. During the SARS-CoV-2 pandemic, there was shortage of the standard respiratory protective equipment (RPE). The aim of this study was to develop a procedure to test the performance of alternative RPEs used in the care of COVID-19 patients. Methods. A laboratory-based test was developed to compare RPEs by total inward leakage (TIL). We used a crossflow nebulizer to produce a jet spray of 1–100 µm water droplets with a fluorescent marker. The RPEs were placed on a dummy head and sprayed at distances of 30 and 60 cm. The outcome was determined as the recovery of the fluorescent marker on a membrane filter placed on the mouth of the dummy head. Results. At 30 cm, a type IIR surgical mask gave a 17.7% lower TIL compared with an FFP2 respirator. At 60 cm, this difference was similar, with a 21.7% lower TIL for the surgical mask compared to the respirator. When adding a face shield, the TIL at 30 cm was further reduced by 9.5% for the respirator and 16.6% in the case of the surgical mask. Conclusions. A safe, fast and very sensitive test method was developed to assess the effectiveness of RPE by comparison under controlled conditions.

Testing out of quarantine

Since SARS-CoV-2 emerged, a 14-day quarantine has been recommended based on COVID-19”s incubation period. Using an RT-PCR or rapid antigen test to “test out” of quarantine is a frequently proposed strategy to shorten duration without increasing risk. We calculated the probability that infected individuals test negative for SARS-CoV-2 on a particular day post-infection and remain symptom free for some period of time. We estimate that an infected individual has a 20.1% chance (95% CI 9.8-32.6) of testing RT-PCR negative on day five post-infection and remaining asymptomatic until day seven. We also show that the added information a test provides decreases as we move further from the test date, hence a less sensitive test that returns rapid results is often preferable to a more sensitive test with a delay.

Thin interfacial film spontaneously produces hydrogen peroxide: mechanism and application on perfluorooctanoic acid degradation

An effective decontamination method for soils remediation is a long-standing challenge. Herein, hydrogen peroxide (H2O2) was spontaneously produced in thin films generated by evaporating almost all the water. H2O2-sensitive test...