Diffusion ordered NMR (DOSY) was applied to the determination of the average molecular weights of polymers based on the dependence of the measured self diffusion coefficient D on the correspond ing weights of a number of polymers of the same type. As a rule, a calibration function is plotted by varying DOSY experimental parameters for each particular test sample; however, this approach is inapplicable to the development of a standard procedure for the quantitative assessment of the molecular weights of dextrans. In this article, an optimization method is considered to ensure high resolution in terms of the values of D for dex trans without varying experimental conditions; this method makes it possible to evaluate the average molec ular weights of dextrans with a high accuracy over a wide range of their values.
Coronaviruses are the largest group of known positive-strand RNA viruses. Coronavirus infection can affect various animal species, as well as humans. Over the past two decades, coronaviruses have caused epidemic outbreaks of two respiratory diseases: the Middle East Respiratory Syndrome and Severe Acute Respiratory Syndrome. At the end of 2019, a new type of virus was detected in China. The virus has been spread by humantohuman transmission and has caused a viral pneumonia outbreak. The emergence of a new coronavirus proves that the diseases caused by this group of viruses pose a threat to global health due to the potential for a pandemic, and, therefore, need careful monitoring. The objective of the study was to analyse the current epidemic situation for the new coronavirus infection (COVID-19) caused by SARS-CoV-2, taking into account previous outbreaks of infections caused by MERS-CoV and SARS-CoV β-coronaviruses which pose the greatest threat to human health. The review briefly describes two epidemic outbreaks caused by SARS-CoV (2002–2004) and MERS-CoV (2012–present), summarises the current epidemic situation for the new SARS-CoV-2 coronavirus, describes the main restrictive measures undertaken to prevent the spread of infection in Russia. The paper considers aspects of potential specific therapy and the development of prophylactic vaccines against the new coronavirus infection. The review concludes that SARS-CoV-2 has pandemic potential and that new strains of β-coronaviruses are likely to cause outbreaks in the future. The paper points to the need for careful monitoring of the disease and conducting preventive anti-epidemic measures to curb the spread of infection.
The possibility of the application of diffusion ordered NMR spectroscopy to the study of the molecular weight distribution of hydroxyethyl starch is investigated. The use of regression equations relating these parameters to the coefficients of the self diffusion of polymer macromolecules as a whole, namely, the average coefficient of self diffusion D s and the coefficient of self diffusion at the peak maximum D p , is pro posed for the quantitative assessment of weight average (M w ) and number averaged (M n ) molecular weights and molecular weight at the peak maximum (M p ). It is shown that the determination of M w , M n , M p based on the data on D s gives the best results. It was found that the values of polydispersity indexes found using diffu sion ordered NMR spectroscopy are independent of the choice of diffusion parameter D s or D p .Keywords: diffusion ordered NMR spectroscopy, parameters of the molecular weight distribution of poly mers, average coefficient of self diffusion, self diffusion coefficient at the peak maximum, hydroxyethyl starch
The review analyses measles incidence in Russia at the elimination stage. Epidemiological studies have revealed changes in the measles epidemic process in Russia. It was shown that whereas the specificity of the epidemic process in the pre-vaccination period was mainly determined by the influence of the infectious agent, lately the impact of the social factor has increased. There was an increase in the impact of decreed groups on maintaining the circulation of the virus in the Russian Federation. The aim of the study was to analyse the specificity of the measles epidemic process in Russia, to identify the major current problems of measles vaccination, to reveal reasons that prevent measles elimination in the country given the present environment, and to formulate possible ways of solving them. The article demonstrates the role of migration processes within the country and infection importation from neighboring territories in the rise of disease outbreaks. The article discusses Russian regulatory documents that are devoted to combating the spread of measles, their consistent replacement and refinement bearing in mind the changing epidemiological situation and the current WHO criteria and guidelines for the infection elimination. High-level epidemiological surveillance of the infection is a key factor in choosing the optimal strategy of measles vaccination. The article lists indicators of epidemiological surveillance effectiveness. It also highlights the importance of molecular genetic monitoring of the measles pathogen. The authors outline measures that are necessary to achieve measles elimination in the Russian Federation given the current epidemiological situation.
Background Severe acute respiratory syndrome corona virus (SARS‐CoV‐2) infection frequently causes severe and prolonged disease but only few specific treatments are available. We aimed to investigate safety and efficacy of a SARS‐CoV‐2‐specific siRNA‐peptide dendrimer formulation MIR 19® (siR‐7‐EM/KK‐46) targeting a conserved sequence in known SARS‐CoV‐2 variants for treatment of COVID‐19. Methods We conducted an open‐label, randomized, controlled multicenter phase II trial (NCT05184127) evaluating safety and efficacy of inhaled siR‐7‐EM/KK‐46 (3.7 mg and 11.1 mg/day: low and high dose, respectively) in comparison with standard etiotropic drug treatment (control group) in patients hospitalized with moderate COVID‐19 (N = 52 for each group). The primary endpoint was the time to clinical improvement according to predefined criteria within 14 days of randomization. Results Patients from the low‐dose group achieved the primary endpoint defined by simultaneous achievement of relief of fever, normalization of respiratory rate, reduction of coughing, and oxygen saturation of >95% for 48 h significantly earlier (median 6 days; 95% confidence interval [CI]: 5–7, HR 1.75, p = .0005) than patients from the control group (8 days; 95% CI: 7–10). No significant clinical efficacy was observed for the high‐dose group. Adverse events were reported in 26 (50.00%), 25 (48.08%), and 28 (53.85%) patients from the low‐, high‐dose and control group, respectively. None of them were associated with siR‐7‐EM/KK‐46. Conclusions siR‐7‐EM/KK‐46, a SARS‐CoV‐2‐specific siRNA‐peptide dendrimer formulation is safe, well tolerated and significantly reduces time to clinical improvement in patients hospitalized with moderate COVID‐19 compared to standard therapy in a randomized controlled trial.
Оценена специфичность различных вариантов методики подтверждения подлинности фармацевтической субстанции «бусерелина ацетат» методом ЯМР спектроскопии путем сравнительного анализа спектров 1H и 13C бусерелина ацетата и [5-D-тирозин]бусерелина ацетата в различных растворителях. Найдено, что максимальное различие в спектральных данных диастереомеров наблюдается при использовании дейтерированной воды в качестве растворителя. Показано влияние растворителя и внутримолекулярных невалентных взаимодействий на обменные прототропные превращения в L-гистидиновом фрагменте анализируемых олигомеров. От скорости прототропной таутомерии зависит ширина сигналов данной аминокислоты в спектрах 13C. Рекомендовано использовать в фармакопейном анализе вариант методики, основанный на 13C ЯМР спектроскопии (растворитель — D2O).
This review focuses on DNA and RNA vaccines whose potential use was first considered at the end of the 20th century. However, not a single bacterial plasmid-based or mRNA vaccine has been used since that time in public healthcare for the prevention of infectious diseases. Nevertheless, vaccines containing recombinant nucleic acids as the active ingredient still attract interest due to the possibility of rapid development, low-cost production, safety of the technology and the potential to activate cellular and humoral immunity. Recent technological advances have largely overcome the problems of low immunogenicity, instability, and difficulties with the delivery of DNA and RNA vaccines in humans. The aim of this review was to present the main strategies of development of DNA and RNA vaccines designed to prevent infectious diseases, and to summarise requirements for the quality control and preclinical studies. The article examines the general principles of creation of plasmid vectors encoding protective antigens. It describes new technologies used in the creation of DNA vaccines with plasmids encoding an attenuated virus genome (iDNA and PPLAV), and RNA vaccines based on mRNA and self-amplifying RNAs. The article presents current regulatory requirements for the choice of quality parameters to be tested and the general principles of preclinical studies of DNA and RNA vaccines.
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