On the construction of a semantically secure modification of the McEliece cryptosystem

The security of currently used asymmetric cryptosystems is based on the problems of discrete logarithm or discrete factorization. These problems can be effectively solved using Shor’s algorithm on quantum computers. An alternative to such cryptosystems can be the McEliece cryptosystem. Its security is based on the problem of decoding a general linear code. In its original form, the McEliece cryptosystem is not semantically secure, from here the problem of constructing a semantically secure cryptosystem of the McEliece type is relevant. In the paper, the goal is to construct a McEliece type cryptosystem that has the IND-CPA property. Further, one can suppose that this system can be used as base cryptosystem for building the McEliece type encryption scheme with the IND-CCA2 property and an efficient information transfer rate

Efficient S-repetition method for constructing an IND-CCA2 secure McEliece modification in the standard model

The paper is devoted to the construction of IND-CCA2-secure modification of the McEliece cryptosystem in the standard model. The modification uses S-repetition encryption of S/2 various messages with one common secret permutation, in contrast to other modifications that use S -repetition encryption of one message. Thus, this modification provides IND-CCA2-security with an efficient information transfer rate

Choosing parameters for one IND- CCA2 secure McEliece modification in the standard model

The paper is devoted to choosing parameters for one IND-CCA2-secure McEliece modification in the standard model. In particular, the underlying code, plaintext length and one-time strong signature scheme are suggested. The choice of parameters for the scheme was based on efficiency, on the one hand, and security, on the other. Also, experiments for the suggested parameters are provided using the NIST statistical test suite. The paper is devoted to choosing parameters for one IND-CCA2-secure McEliece modification in the standard model. In particular, the underlying code, plaintext length and one-time strong signature scheme are suggested. The choice of parameters for the scheme was based on efficiency, on the one hand, and security, on the other. Also, experiments for the suggested parameters are provided using the NIST statistical test suite

Clinical case of catatonic stupor developed as a result of acute respiratory disease COVID-19

The aim of this work is to demonstrate and analyze a clinical case of catatonic stupor as a consequence of the complex effect of the infectious process, namely systemic inflammation and direct neurotoxicity of the SARS-CoV-2 virus on the nervous system. A retrospective analysis of outpatient and inpatient medical records was performed. . Analysis of clinical case proves the possibility of catatonic syndrome due to acute respiratory disease COVID-19. 2. Given that catatonia is an urgent condition, it is necessary to be vigilant about its occurrenc

Cost-effectiveness analysis of pembrolizumab versus targeted therapies in advanced melanoma

Background. The modern therapies of advanced melanoma include targeted medicines for patients with BRAF mutations. Nowadays, a new perspective on immuno-oncologic medicine pembolizumab became available in Russia. Objective. Assessment of the clinical and economic effectiveness of the use of pembolizumab in the treatment of unrespectable and metastatic melanoma in comparison with targeted medicines in the context of Russian public health. Materials and methods. The Markov model was developed, including the states «without progression», «after progression» and «death», the duration of one Markov cycle is 1 month, the modeling time horizon is 5 years. The probabilities of transitions between states were described using mathematical formulas obtained as a result of digitization and approximation of Kaplan-Mayer survival curves, which were derived from randomized clinical trials KEYNOTE-006, COMBI-v and COMBI-d. Direct medical costs (including drug costs, treatment of adverse events, second-line therapy after disease progression, and palliative care) were analyzed. We did not take into account the costs associated with laboratory-diagnostic procedures and visits to the doctor. The sources of information were: weighted average prices of medicines indicated during public procurement for 2016 (the price of the drug pembolizumab provided by the manufacturer), a program of state guarantees for providing free medical care to Russian citizens for 2016, federal coefficients of relative costs for clinical and statistical groups. The effectiveness criterion for cost-effectiveness analysis was the average number of saved months of a patient’s life. Results. The average number of months saved was 30, 23, 24 and 30 months with pembolizumab, vemurafenib, dabrafenib and dabrafenib plus tramethanib, respectively (calculated using the developed model). Thus, pembolizumab has the same effectiveness as a combination of dabrafenib + tramethanib and is more effective than monotherapy with targeted drugs (dabrafenib or vemurafenib). Direct medical costs per patient over 5 years were approximately 4.06, 5.53, 5.91 and 15.72 million rubles when using pembolizumab, dabrafenib, vemurafenib and a combination of dabrafenib + trametinib, respectively. The health budget saving with pembolizumab instead of dabrafenib, vemurafenib and dabrafenib + trametinib combination may be 26%, 31% and 74%, respectively. Conclusion. Pembolizumab is a rational and economically justified choice for the treatment of unresectable and metastatic melanoma since it leads to cost savings when overall survival is increased

Antiplatelet activity of new derivatives of benzimidazole containing sterically hindered phenolic group in their structure

The chemical class of benzimidazole derivatives with a hindered phenolic substituent in their structure is promising for the search for new antiaggregant and antioxidant drug

Engineering and Characterization of an Enhanced Fluorescent Protein Voltage Sensor

BACKGROUND: Fluorescent proteins have been used to generate a variety of biosensors to optically monitor biological phenomena in living cells. Among this class of genetically encoded biosensors, reporters for membrane potential have been a particular challenge. The use of presently known voltage sensor proteins is limited by incorrect subcellular localization and small or absent voltage responses in mammalian cells. RESULTS: Here we report on a fluorescent protein voltage sensor with superior targeting to the mammalian plasma membrane and high responsiveness to membrane potential signaling in excitable cells. CONCLUSIONS AND SIGNIFICANCE: This biosensor, which we termed VSFP2.1, is likely to lead to new methods of monitoring electrically active cells with cell type specificity, non-invasively and in large numbers, simultaneously

Безопасность применения гипербарической оксигенации при лечении COVID-19

Relevance. Acute respiratory infection COVID-19 caused by the SARS-CoV-2 (2019-nCov) coronavirus is severe and extremely severe in 15—20% of cases, which is accompanied by the need for respiratory support. Hyperbaric oxygenation is recognized as an effective therapy for replenishing any form of oxygen debt.Aim of study. To study the safety of HBO use in patients with COVID-19.Material and metods. We examined 32 patients with the diagnosis “Coronavirus infection caused by the virus SARS-CoV-2” (10 — moderately severe patients (CT 1–2), 22 — patients in serious condition (CT 3–4), who received course of hyperbaric oxygenation (HBO). The procedures were carried out in a Sechrist 2800 chamber (USA) at a mode of 1.4–1.6 AT for no more than 60 minutes. In total, the patients received 141 HBO sessions. Before and after each HBO session, the subjective indicators of the patient’s condition were assessed and the blood oxygen saturation was measured.Results. An algorithm for HBO course management was developed, which consists in using “soft” modes (up to 1.4 AT) during the first session, followed by pressure adjustment (not higher than 1.6 AT) during the course to achieve maximum therapeutic effect and comfort for the patient. Against the background of the HBO course, the patients showed an increase in blood oxygen saturation in patients in both surveyed groups, as well as positive dynamics in the form of a decrease in shortness of breath, an improvement in general well-being.Conclusion. The inclusion of daily sessions (at least 4) of hyperbaric oxygenation in “soft” modes (1.4–1.6 ATA) in the complex therapy for COVID-19 has shown its safety and preliminary positive effect on the subjective state of the examined patients and the dynamics of blood oxygen saturation.Актуальность. Острая респираторная инфекция COVID-19, вызываемая коронавирусом SARS-CoV-2 (2019-nCov), в 15–20% случаев протекает в тяжелой и крайне тяжелой степени, что сопровождается необходимостью респираторной поддержки. Гипербарическая оксигенация признана эффективным средством терапии, восполняющим любые формы кислородной задолженности.Цель работы. Исследование безопасности применения гипербарической оксигенации (ГБО) у пациентов с COVID-19.Материал и методы. Были обследованы 32 пациента с диагнозом «Коронавирусная инфекция, вызванная вирусом SARS-CoV-2» (10 — больные средней тяжести (КТ 1–2), 22 — больные в тяжелом состоянии (КТ 3–4)), которым был назначен курс гипербарической оксигенации (ГБО). Процедуры осуществляли в реанимационной барокамере Sechrist 2800 (CША) при режиме 1,4–1,6 АТА в течение не более 60 минут. Всего пациенты получили 141 сеанс ГБО. До и после каждого сеанса ГБО оценивали субъективные показатели состояния пациентов и измеряли насыщение крови кислородом.Результаты исследования. Был разработан алгоритм ведения курса ГБО, заключающийся в использовании при первом сеансе «мягких» режимов (до 1,4 АТА) с последующей корректировкой давления (не выше 1,6 АТА) в течение курса для достижения максимального терапевтического эффекта и комфорта для пациента. На фоне проведения курса ГБО у пациентов было отмечено повышение насыщения кислородом крови у пациентов в обеих обследованных группах, а также положительная динамика в виде уменьшения одышки улучшения общего самочувствия.Заключение. Включение в комплексную терапию при COVID-19 ежедневных сеансов (не менее 4) гипербарической оксигенации в «мягких» режимах (1,4–1,6 АТА) показало свою безопасность и предварительный положительный эффект на субъективное состояние обследованных пациентов и динамику насыщения крови кислородом

Hyperbaric Oxygen Therapy in Patients with COVID-19

The aim of the study is to evaluate the efficacy of hyperbaric oxygen therapy and its effect on oxidative stress and apoptosis in patients with new coronavirus infection COVID-19.Materials and methods. 90 patients diagnosed with new coronavirus infection caused by SARS-CoV-2 virus were examined. Hyperbaric oxygen therapy sessions were conducted in 57 patients (38 in severe condition (CT 3-4), 19 in moderate condition (CT 1-2)). The procedures were performed in 1.4-1.6 ATA mode for 40 minutes, 247 sessions in total were performed. The effect of hyperbaric oxygenation was assessed by measuring the level of oxygen saturation, the severity of oxidative stress and apoptosis of blood lymphocytes.Results. In all examined patients with new coronavirus infection caused by SARS-CoV-2, positive changes such as dyspnea reduction and improvement of general well-being were registered after hyperbaric oxygen therapy sessions. The level of oxygen saturation after the end of the hyperbaric oxygen therapy course was 95.0±1.6% (before the course — 91.3±5.9%), which allowed to return almost all patients to spontaneous respiration without the need for further oxygenation therapy. Hyperbaric oxygen therapy did not reduce the total antioxidant activity, however, it was associated with a decrease in the blood malone dialdehyde from 4.34±0.52 pmol/l to 3.98±0.48 pmol/l and a decrease in open circuit potential of platinum electrode from -22.78±24.58 mV to -37.69±17.4 mV. Besides, the positive effect of hyperbaric oxygen therapy was manifested in normalization of blood cell apoptosis.Conclusion. Hyperbaric oxygen therapy in patients with new coronavirus infection caused by the SARS-CoV-2 virus is an effective treatment method with multiple effects resulting in improvement of subjective indicators of the patients' condition, increase of hemoglobin oxygen saturation, decrease of lipid peroxidation intensity, activation of antioxidant system, restoration of pro- and antioxidant balance and apoptosis normalization