Метатезис катионов аммония в (NH4)4[Mo12O28(μ-L)8] (L = pz (пиразолат) и trz(1,2,4-триазолат)) на тетрабутиламмоний проведен при кипячении в водном растворе с Bu4NOH. Замещение катионов и сохранение анионного кластерного фрагмента подтверждено рядом физико-химических методов анализа, включая рентгеноструктурный анализ, 1H ЯМР-спектроскопию и масс-спектрометрию. Полученные соединения растворимы и стабильны в органических растворителях, что позволило изучить их окислительно-восстановительные свойства. Согласно данным циклической вольтамперометрии соединения проявляют обратимое окисление с E1/2 = 0.26 и 0.61 В для L = pz и trz соответственно. С помощью квантово-химических расчетов изучена электронная структура и показано, что основной вклад в граничные молекулярные орбитали соединений вносят d-орбитали молибдена.

The metathesis of ammonium cations in (NH4)4[Mo12O28(μ-L)8] (L = pz (pyrazolate) and trz (1,2,4-triazolate)) with tetrabutylammonium is performed under boiling in an aqueous solution with Bu4NOH. The substitution of cations and the preservation of the anionic cluster fragment are confirmed by a number of physicochemical methods such as XRD, 1H NMR, and mass spectrometry. The resulting compounds are soluble and stable in organic solvents, so their redox properties are studied. According to the cyclic voltammetry data, the compounds exhibit reversible oxidation with E1/2 = 0.26 V and 0.61 V for L = pz and trz respectively. The electronic structure is studied by quantum chemical calculations. It is shown that the frontier molecular orbitals of these compounds are mainly composed of molybdenum d-orbitals.

The [Re6Te8(imzH)6]2+ cationic cluster complex prepared by the interaction of [Re6Te8 (TeI2)6]I2·[Re6Te8(TeI2)4(TeI3)2]·I2 with imidazole (imzH) in a sealed glass ampoule at 200 °C for 48 h. The composition of the obtained compound is confirmed by 1H NMR spectroscopy and high-resolution mass spectrometry. The single crystals suitable for SC-XRD are prepared by slow diffusion of diethyl ether vapors into a solution of the complex in DMF. According to the SC-XRD data, the resulting complex has the composition [Re6Te8(imzH)6]I2·2/3DMF. The compound crystallizes in the monoclinic crystal system, P21/c space group, with the following unit cell parameters: a = 18.0379(4) Å, b = 17.9945(5) Å, c = 33.1318(7) Å, β = 115.1829(10)°, V = 9732.0(4) Å3, Z = 6. It is also shown that this compound exhibits solid-state luminescence with an emission maximum at 730 nm characteristic of octahedral rhenium cluster complexes.

Currently, the search for new effective materials with photocatalytic properties to combat various organic pollutants, including wastewater treatment, is quite urgent. In this work, we obtained a new material based on hexagonal boron nitride modified with hydroxo groups (nanoBN–OH) and the photoactive octahedral cluster complex [Mo6I8(DMSO)6](NO3)4. Analysis of the obtained samples by transmission electron microscopy showed that the cluster complex in the hybrid material was present in the form of nanoparticles with a diameter of 10–30 nm. Their photocatalytic activity in the decomposition of model dyes, methyl orange and Rhodamine B, was studied, their efficiency was demonstrated, and the effective reaction rate constants were determined.

Background. The pandemic of COVID-19 raised safety concerns for healthcare workers while non-medical personnel were left unattended. Comparing the levels of seroprevalence to SARS-CoV-2 and vaccination in different employee groups will allows us to assess the risk of infection and develop a strategy to minimize the spread of infections in medical institutions in future.The aim. To identify the level of seroprevalence to SARS-CoV-2 for seven groups of medical center workers. Methods. The seroprevalence to SARS-CoV-2 was analyzed in 361 employees of the ophthalmology center in mid-2021. Data on the level of specific IgM and IgG antibodies were compared with questionnaire, including occupation data.Results. Depending on occupation, workers were divided into seven groups. The average seroprevalence rate for all employees was 82.3 %, and the percentage of vaccinated employees was 27.4 %. The lowest level of seroprevalence was found in the group of maintenance staff (55.0 %) which is significantly lower (p ˂ 0.05) than in the groups of doctors (84.4 %), nurses (85.6 %), administrative stuff (82.6 %) and cafeteria stuff (77.7 %). The seroprevalence rate for cleaning staff was 84.6 % and for pharmacy workers it was 80 %. The highest vaccination coverage was among doctors – 50.0 %, the lowest was among cafeteria and kitchen staff – 7.4 %.Discussion. We believe the high seroprevalence is associated with asymptomatic spread of SARS-CoV-2.Conclusions. High seroprevalence was among doctors and nurses, pharmacy workers, canteen workers, cleaners, as well as administration workers. Anti-epidemic measures for these groups will reduce the spread of infectious diseases and help retain staff during the seasonal increase in incidence.

Катионный кластерный комплекс [{Re6Te8}(imzH)6]2+ получен взаимодействием [{Re6Te8}(TeI2)6]I2·[{Re6Te8}(TeI2)4(TeI3)2]·I2 с имидазолом (imzH) в запаянной стеклянной ампуле при 200 °С в течение 48 часов. Состав полученного соединения был подтвержден с помощью 1Н ЯМР спектроскопии, а также масс-спектрометрии высокого разрешения. Путем медленной диффузии паров диэтилового эфира в раствор комплекса в ДМФА удалось получить монокристаллы пригодные для рентгеноструктурного анализа, согласно данным которого образуется [{Re6Te8}(imzH)6]I2·2/3DMF. Соединение кристаллизуется в моноклинной сингонии, пространственная группа Р21/c, с параметрами элементарной ячейки a = 18.0379(4), b = 17.9945(5), c = 33.1318(7) Å, β = 115.1829(10)⁰, V = 9732.0(4), Z = 6. Более того, было показано, что соединение проявляет характерную для октаэдрических кластерных комплексов рения люминесценцию в твердом теле, с максимумом эмиссии 730 нм.

Background. Studying the characteristics of the course of coronavirus infection caused by SARS-CoV-2 remains relevant due to the high mutagenicity of the virus and the prevalence of the disease in the world. The search for new drugs to eliminate clinical manifestations of COVID-19, as well as against its agent, is essential. During the pandemic caused by SARS-CoV-2, dexamethasone was recognized as the only effective anti-inflammatory drug for the treatment of patients with severe form of the disease, but its use leads to a large number of side effects.The aim. To study the therapeutic effect of the drug Molixan in the treatment of coronavirus infection in model animals – Syrian hamsters.Methods. To assess the effectiveness of the drug Molixan, we carried out a visual assessment of the condition of the lungs using light microscopy and the morphometry of the lung tissue of experimentally infected Syrian hamsters on the day 6 after infection under different Molixan treatment regimens and during dexamethasone therapy. The test drug was administered using three different doses (22.2 mg/kg, 44.4 mg/kg and 88.8 mg/kg, which are equivalent to doses of 3 mg/kg, 6 mg/kg and 12 mg/kg of human body weight) once daily or dividing the dose into two within 12 h interval in case of multiple (5 days) intramuscular administration. Dexamethasone (comparison drug) was administered at a dose of 20 mg/kg once daily for 5 days.Results. The studies showed statistically significant effectiveness of using Molixan at a dose of 44.4 mg/kg, divided into two doses, during 5 days. When compared with untreated hamsters, this treatment regimen reduces the degree of generalization and severity of the inflammatory process in the lungs; and the pathomorphological picture is similar to that observed during treatment with Dexamethasone.Conclusion. The studied drug Molixan is effective as an anti-inflammatory drug in the treatment of the disease caused by SARS-CoV-2.

Relevance. Influenza A virus is characterized by a segmented single-stranded RNA genome. Such organization of the virus genome determines the possibility of reassortment, which can lead to the emergence of new virus variants. The main natural reservoir of most influenza A virus subtypes are wild waterfowl. Seasonal migrations gather waterfowl from all major migration routes to nesting areas near the northern and southern polar circles. This makes intercontinental spread of influenza A viruses possible. Objective ‒ to conduct molecular genetic monitoring and study the phylogenetic relationships of influenza A virus variants circulating in Antarctica in 2023. Materials and methods. We studied 84 samples of biological material obtained from birds and marine mammals in April‒May 2023 in coastal areas of Antarctica. For 3 samples, sequencing was performed on the Miseq, Illumina platform and phylogenetic analysis of the obtained nucleotide sequences of the influenza A virus genomes was performed. Results. The circulation of avian influenza virus in the Antarctic region was confirmed. Heterogeneity of the pool of circulating variants of the influenza A virus (H3N8, H1N1) was revealed. Full-length genomes of the avian influenza virus were sequenced and posted in the GISAID database (EPI_ISL_19032103, 19174530, 19174467). Conclusion. The study of the genetic diversity of influenza A viruses circulating in the polar regions of the Earth and the identification of the conditions for the emergence of new genetic variants is a relevant task for the development of measures to prevent biological threats.

A cluster complex of the composition [Re6Te8(TeI2)6]I2·[Re6Te8(TeI2)4(TeI3)2]·I2 is obtained by a reaction between [Re6Te8Te7] and I2 in a sealed quartz ampoule at 400 °C. More than three times increase in the volume of the ampoule in which the reaction is performed with maintaining the other conditions is shown to lead to the formation of the previously described cluster complex [Re6Te8(TeI2)6]I2. An increase in the synthesis temperature to 450 °C leads to the formation of X-ray amorphous products of the unknown composition. The [Re6Te8(TeI2)6]I2·[Re6Te8(TeI2)4(TeI3)2]·I2 compound obtained at 400 °C crystallizes in the triclinic crystal system, space group P1̅ , and unit cell parameters a = 11.0859(3) Å, b = 11.9021(4) Å, c = 21.1308(7) Å, α = 79.259(2)°, β = 85.533(2)°, γ = 66.220(2)°, V = 2506.55(14) Å3, Z = 1. The crystal structure consists of four layers of two types that alternate along the c parameter: 1) the layer formed by iodine anions and [Re6Te8(TeI2)6]2+ cluster cations and 2) the layer formed by neutral cluster complexes [Re6Te8(TeI2)4(TeI3)2] and crystallization I2 molecules. Weak interactions between the adjacent cluster complexes are observed in both layers along with I⋯I halogen bonds. The layers are linked with each other via I⋯I and Te⋯I interactions.

The review presents current data on the chiropterofauna inhabiting Western Siberia and the south of the European part of Russia. A general description of the genus of lyssaviruses and the family of coronaviruses is given. The potential for virus carriage in relation to lyssaviruses and coronaviruses in bat populations of two geographically distant regions is considered.

The ligand environment of the [{Mo_5S_5^i(pz)_4^i}(pzH)_5^t]Br_2 cluster complex is modified by a reaction of the cluster with Br 2 in N,N-dimethylformamide at room temperature, which results in bromination of all pyrazole and pyrazolate ligands at the fourth position and in bromide ligand substitution for apical pyrazole. The solvent effect on ligand bromination is considered. The [{Mo_5S_5^i(4-Br-pz)_4^i}(4-Br-pzH)_4^bsBr^a]Br·Et_2O·5DMF cluster complex crystallizes in the tetragonal symmetry (space group P 4/ n ) and forms infinite layers via hydrogen bonds between the terminal 4-bromopyrazole ligands and the bromine anion. The complex also demonstrates reversible one-electron reductions of the cluster core shifted relative to the initial compound by 30 mV and 90 mV towards larger potentials.

Nanosized (d ∼70 nm) particles of metal-organic framework (MOF) based on zirconium and 2-aminoterephthalic acid, NH2-UiO-66, were prepared by a simple one-pot method. Due to the small particle size, the presence of amino groups, low toxicity, and high sorption capacity caused by large pore size, the obtained MOF is a perfect platform for the preparation of combined cytostatic agents with prolonged action. Nano-MOF is highly stable in distilled water, which allows for the sorption of a cytostatic drug without crystal destruction. The MOF gradually loses crystallinity in phosphate-buffered saline (pH 7.4), resulting in a gradual release of the drug under near-physiological conditions. Sorption studies have shown that approximately 50

We investigated the incidence of 15 respiratory viruses among 2991 children with acute respiratory infections in Novosibirsk city, Russia, prior to the COVID-19 pandemic (2013–2020). Viral infections were detected in 72.5% cases. The incidence of human coronavirus was 2% (Alphacoronaviruses, 63%; Betacoronaviruses, 37%).

Under conditions of COVID-19 pandemic, considerable amounts of SARS-CoV-2 contained in household, municipal, and medical wastewaters inevitably reach natural water bodies. Possible preservation of virus infectivity in liquid environment is of a paramount epidemiological importance. Experiments demonstrated that SARS-CoV-2 is resistant to multiple freezing/thawing cycles and retains its infectivity in tap and river water for up to 2 days at 20°C and 7 days at 4°C. In natural milk, its viability is preserved in a refrigerator for 6 days. The exposure of aquarium fish to the virus-containing water fails to cause any infection.

Superior mesenteric artery (SMA) syndrome is a rare cause of upper gastrointestinal obstruction. Nutcracker syndrome occurs as the result of external compression of the left renal vein. Although they share a similar pathophysiology, SMA and nutcracker syndrome occurring simultaneously is rare. In this case report, we discuss the pathophysiology and unique computed tomography findings in a 25-year-old female patient diagnosed with SMA syndrome who was also incidentally found to have a coexisting nutcracker phenomenon. Due to similar pathogenesis, radiologists should consider the possibility of coexistence of these rare syndromes in appropriate patients.

Lassa fever is a natural focal disease dangerous for humans. In the larger part of sub-Saharan West Africa 37.7 million people in 14 countries live in areas where living conditions are suitable for zoonotic transmission of the virus from secretions of infected rodents of the species Mastomys natalensis. Routes of transmission can be via alimentary, airborne dust or airborne droplet pathways in case of accidental human contact with secretions of infected rodents. Mastomys natalensis penetrates into residence and place of storage of food and drinking water. In addition, the residents use such animals for food, so infection is also possible upon butchering carcasses. The etiological agent of this disease is the Lassa virus being one of the members of the Arenaviridae family. Unlike other arenavirus infections (e.g., Argentine and Bolivian fevers caused by Junin viruses and Machupo, respectively), human infection with Lassa virus can also occur from person to person. Cases of nosocomial infection among patients in conditions of poor hygiene and through contaminated medical equipment are described. Medical workers become infected during surgical operations or through contact with patients, because the pathogen can be transmitted via blood, saliva, vomiting, stool or urine. In endemic territories, Lassa fever is associated with significant morbidity, because 500 thousand clinical cases and due to 5 to 10 thousand fatal outcomes of this disease are registered annually (i.e. 12% mortality). The likelihood that this disease will become a more widespread threat worldwide may be associated with increased globalization as well as climate change leading to the expansion of the Lassa fever endemic zone into regions suitable for the settlement of M. natalensis and other rodent species capable of lifelong pathogen carriage. Among hospitalized persons with severe hemorrhagic symptoms, the mortality rate can be very high ranging from 14 to 89.5%. But in the majority of cases, the disease proceeds asymptomatically, and due to its long-term incubation period all ill subjects may be a source of infection, especially travelling at long distance by plane or train. Clinically evident disease occurs in the form of various nonspecific symptoms from malaise, fever, sore throat and chest, cough, myalgia and gastrointestinal disorders to signs of central nervous system disorders. The diagnosis of Lassa fever is often difficult due to the similarity of its course with other viral diseases common in Africa or malaria or typhoid fever. More specific symptoms for Lassa fever are revealed as conjunctivitis, hepatitis, pharyngitis, tonsillitis as well as developing oropharyngeal ulcers. Severe disease is complicated by abnormal bleeding, generalized edema, respiratory failure, hypotension, proteinuria, transaminitis, encephalopathy. Deafness develops in about 20% of cases. Multiple organ failure and open bleeding lead to death. The review is devoted to analyzing publications on the etiology, epidemiology and clinical picture of Lassa fever due to a threat of its importation with sick subjects to the territory of the Russian Federation.

Globalization and high-speed means of transportation contribute to the spread of infections dangerous to humans. Airborne pathogens have pandemic potential as currently shown in case of the novel coronavirus SARS-CoV-2. Natural focal Lassa fever (LF) common in West African countries, in 35 cases was registered in non-endemic geographical areas because any person infected with Lassa virus (LASV) is a long-term source of infection (up to two months). Cases of person-to-person infection in endemic territories are described. In Germany, the facts of secondary virus transmission from patients to doctors have been recorded during the examination and blood collection from an apparently healthy person as well as during the autopsy of a deceased subjects due to severe LF course. Nonspecific malaise symptoms in LF are also characteristic of numerous other diseases common on the African continent, e.g., malaria and typhoid fever or viral infections such as yellow fever, Chikungunya, dengue and Zika, monkey pox and Ebola virus disease. In this regard, there may be similar dermatological manifestations. Timely detection of cases and differential diagnosis are crucial to ensure safe patient care and use of affordable antiviral therapy for LL provided by the drug Ribavirin. Research methods for studying LASV use polymerase chain reaction (PCR) for detecting viral RNA, electron microscopy, isolation of infectious virus cultured sensitive cells, indirect immunofluorescence reaction, enzyme immunoassay (ELISA) and immunochromatographic assays for the detection of antibodies and/or antigen as well as immunoblotting. Currently, test kits based on molecular and genetic methods are mainly used for LF laboratory diagnostics. Since the 1980s, ribavirin has been used to treat patients with LF. The serum accumulation of the drug in large quantities causes hemolysis, development of anemia and impaired renal function. In this regard, treatment options are being considered with decline in its concentration due to combined use with other antiviral drugs. A search for new therapeutic agents capable of inhibiting viral replication at disease early stage has been in progress due to lack of any approved vaccines.

Since coronaviruses can remain infectious on different inanimate surfaces for several hours or even days, the possibility of indirect fomite transmission through infected objects and surfaces cannot be ruled out. We describe a method for the photodynamic disinfection of inanimate surfaces infected with severe acute respiratory syndrome coronavirus 2, Omicron variant strain. Application of only 5 µ M photosensitizer octakis(cholinyl)zinc phthalocyanine followed immediately by 7 min irradiation with light emitting diode (LED) light 692 nm (12.5 mW cm −2 ) results in complete inactivation of the virus on polystyrene and glass surfaces, while 10 min irradiation lead to complete eradication of the virus also on Al-foil and medical mask fabric. A photodynamic technique is being considered to combat the spread of coronaviruses.

Dengue fever known from literary sources since the Qin dynasty (265-420) is caused in humans when bitten by Aedes mosquitoes infected with the dengue virus (DENV) and manifests as a flu-like disease. A feverish state can be accompanied by dyspeptic disorders (nausea, vomiting, diarrhea) and a rash. Approximately 1-2% of infections are clinically presented as the most severe form – it is dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) leading to 500 thousand annual hospitalizations with a mortality rate of about 5% in endemic areas.Four genetically removed DENV serotypes (1, 2, 3, and 4) are classified as different types of viruses within the same antigen complex and have almost identical epidemiological features. In 2013 a new serotype DENV-5 was isolated.Until the 1980s in most geographical regions of the world where dengue fever was registered only one or two viral serotypes were detected as an etiological agent of the disease. Over time there is an increase in the cocirculation of four types of viruses which can serve as a key indicator of their global spread. As the “traces” of the four DENV species overlap more and more the threat of severe disease increases due to the phenomenon of antibody-dependent of infection when re-infected with a heterologous viral serotype.Development of specific dengue fever prevention has been underway since 1944 (since the discovery of viral agents of this disease) but the first and so far only licensed in 2015 tetravalent vaccine-Dengvaxia developed by the French pharmaceutical company Sanofi Pasteur has been effective in varying degrees of protection against infection with each of the viral serotypes and in addition dangerous for previously seronegative people. Research aimed at obtaining a safe and effective vaccine is continuing. Neutralizing monoclonal antibodies are a necessary tool for studying the antigenic structure of viral immunogens as base of prevention preparates against dengue fever.