Double Fe-impurity charge state in the topological insulator Bi2_2Se3_3

The influence of individual impurities of Fe on the electronic properties of topological insulator Bi$_2$Se$_3$ is studied by Scanning Tunneling Microscopy. The microscope tip is used in order to remotely charge/discharge Fe impurities. The charging process is shown to depend on the impurity location in the crystallographic unit cell, on the presence of other Fe impurities in the close vicinity, as well as on the overall doping level of the crystal. We present a qualitative explanation of the observed phenomena in terms of tip-induced local band bending. Our observations evidence that the specific impurity neighborhood and the position of the Fermi energy with respect to the Dirac point and bulk bands have both to be taken into account when considering the electron scattering on the disorder in topological insulators.Comment: 10 pages, accepted for publication in Applied Physics Letters, minor bugs were correcte

Angle-closure glaucoma, iris-lens contact, ciliochoroidal effusion, and transient myopia induced by topiramate

Topiramate is a sulphonamide derivative indicated in the treatment of epilepsy and migraine. In foreign scientific literature there are reported cases of topiramate-induced bilateral angle-closure glaucoma and acute myopia with ciliochoroidal effusion.Purpose. To evaluate outcomes of laser iridectomy in a patient with topiramate-induced angle-closure glaucoma and acute myopia with ciliochoroidal effusion.Material and methods. A case is reported of bilateral angle-closure glaucoma, iris-lens contact, ciliochoroidal detachment and acute myopia following topiramate for migraine treatment in a 32-year-old patient. Laser peripheral iridectomy was performed in the both eyes according to the standard technology (Nd:YAG laser Selecta Trio, Lumenis Ltd., Israel) to decrease IOP and restore visual functions.Results. After laser iridectomy, the examination showed normal IOP with no medication, ciliochoroidal effusion and induced myopic shift were relieved.Conclusion. Laser iridectomy is an effective and safe in the treatment of topiramate-induced angle-closure glaucoma, acute myopia, and ciliochoroidal detachment. It contributes to normalization of IOP and improvement of visual acuity

Eye Hydrodynamics after Combined Treatment of Primary Open-Angle Glaucoma and Complicated Cataract

Aim: To study hydrodynamics of the eye after combined treatment – a combination of laser activation of trabecula and cataract phacoemulsification – in a comparative aspect.Material and methods. The study included 65 patients (65 eyes) with initial and advanced stages (I–II stages) of primary open-angle glaucoma (POAG) and complicated cataract. Among the patients there were 38 women (58.5 %) and 27 men (41.5 %), the average age was 68.8 ± 8.2 years. The follow-up period is 12 months after the treatment. The patients were divided into two groups: the main one – 33 patients (33 eyes) who underwent combined treatment – YAG-laser activation of trabecula (YAG-LAT) and phacoemulsification of cataract with intraocular lens (IOL) implantation, the control group – 32 patients (32 eyes) who underwent only phacoemulsification.Initially, the average intraocular pressure (IOP) (P0) in the main and control groups was 20.72 ± 3.39 mm Hg and 21.02 ± 3.55 mm Hg respectively. The average number of antihypertensive drugs used in the study group was 1.53 ± 0.64, in the control group – 1.34 ± 0.55.Results. There were no intraand postoperative complications. By the end of the follow-up period, a significant decrease in the average IOP level compared to its preoperative value by 29.2 % was determined in the main group, and 9.8 % in the control. The average number of antihypertensive drugs used in the study group decreased from 1.53 ± 0.64 to 0.67 ± 0.59 (p < 0.05), in the control group of patients, on the contrary, the average number of antihypertensive agents increased from 1.34 ± 0.55 to 1.91 ± 0.70 (p < 0.05).Conclusion. In the long-term postoperative period after combined treatment (YAG-LAT + phaco), IOP normalization was achieved in 96.9 % of cases, as well as a significant increase in visual acuity of patients. The developed method of treatment is safe, has a minimal risk of complications and can be used for the treatment of patients with initial stages of POAG in combination with complicated cataracts with increased IOP level, inefficiency of antihypertensive therapy

Инновационные технологии при комбинированной хирургии глаукомы и осложненной катаракты

The review considers possible treatment tactics for patients with open-angle glaucoma and coexisting cataract. Combined treatment is recommended in the case of subcompensation of intraocular pressure (IOP) and a significant decrease in visual functions, because it allows achieving a more pronounced hypotensive effect, versus the phacoemulsification alone. The advantage of one-step intervention lies in the optimization of economic, social, psychological aspects, and shortening the patient's period of rehabilitation. In recent years, the methods of minimally invasive glaucoma surgery (MIGS) have become most relevant and common. The safety and technical simplicity of MIGS procedures, as well as their success in combination with phacoemulsification, ensured a widespread dissemination of these interventions. According to a number of scientific studies, the implementation of MIGS-technologies simultaneously with phacoemulsification contributes to the achievement of optimal results. The review considers the main groups of MIGS methods, presents the results of clinical studies devoted to their effectiveness. It presents the data on the efficacy of combined MIGS technologies with phacoemulsification and MIGS methods alone. There is a great interest in studying modern microinvasive methods of laser treatment in the combined treatment of patients with POAG and cataract. These operations have a minimal damaging effect on the trabecular tissue and have a pathogenetic orientation. The development of microinvasive-combined methods of treatment of POAG and complicated cataract remains an actual and promising direction.В обзоре рассмотрены возможные варианты тактики лечения пациентов с открытоугольной глаукомой и осложненной катарактой. При субкомпенсации внутриглазного давления (ВГД) и значительном снижении зрительных функций показано комбинированное лечение, т. к. оно позволяет добиться более выраженного гипотензивного эффекта, в отличие от операции факоэмуль-сификации катаракты. Преимуществом одномоментного вмешательства является оптимизация экономических, социальных, психологических аспектов, сокращение периода реабилитации пациента. Методики минимально инвазивной хирургии глаукомы — MIGS (minimally invasive glaucoma surgery) в последние годы становятся наиболее актуальными и распространенными. Безопасность и техническая простота методик MIGS, а также успешность при комбинации с факоэмульсификацией обеспечили широкое распространение данных вмешательств. Согласно ряду научных исследований, выполнение MIGS-технологий одномоментно с факоэмульсификацией катаракты способствует достижению оптимальных результатов. В обзоре рассмотрены основные группы методик MIGS, представлены результаты клинических исследований, посвященных изучению их эффективности. Приведены сравнительные данные о гипотензивном эффекте MIGS-технологий, проведенных изолированно, а также в сочетании с факоэмульсификацией катаракты. Большой интерес вызывают современные малоинвазивные методики лазерного лечения в комбинированном лечении больных первичной открытоугольной глаукомой (ПОУГ) и катарактой. Данные операции оказывают минимальное повреждающее действие на трабекулярную ткань и обладают патогенетической направленностью. Разработка микроинвазивных комбинированных способов лечения ПОУГ и осложненной катаракты остается актуальным и перспективным направлением

Application of synchrotron radiation to study the surface atomic structure of 2D materials

In this paper, the current state of X-ray photoelectron diffraction and holography methods are considered. A brief overview of surface research methods is given. The photoelectron diffraction method is attractive for use because of its sensitivity to the chemical environment, as well as its large depth of analysis (units of nanometers). The paper presents the application of methods for studying the atomic structure of bismuth chalcogenides Bi2X3 (X: Se,Te). The results of the holography were verified by theoretical modeling of diffraction patterns using the EDAC algorithm. © 2020 American Institute of Physics Inc. All rights reserved.The reported study was funded by RFBR, project number 19-29-12061 and was carried out within the state assignment of Ministry of Science and Higher Education of the Russian Federation (theme “Spin” No. АААА-А18-118020290104-2). L.V.Yashina acknowledges the support of her experimental work by RSF, grant 19-42-06303. We thank HZB for the allocation of synchrotron radiation beamtime

Hantaviruses in Insectivore Populations in Siberia

Objective of the study was investigation of hantaviruses in a new natural reservoir - insectivores, their diversity and geographic distribution in the Western and Eastern Siberia. Materials and methods. Sorex shrews (71 specimens) were captured in Altai Republic, Altai, and Krasnoyarsk Territories, and Omsk Region. All samples were analyzed for hantavirus RNA using reverse transcription polymerase chain reaction with subsequent sequencing. Results and conclusions. A total of 12 viral RNA isolates from two Sorex species (S. araneus and S. roboratus) were genetically typed. Sequence analysis of the partial L and S segments identified two distinct hantaviruses. Kenkeme (KKMV) virus was detected in a flat-skulled shrew (S. roboratus) in Altai Territory. This virus was previously found in geographically remote sites in the Sakha Republic and China. New foci of Seewis virus circulation among common shrews (S. araneus), were found in the Omsk Region, Altai and Krasnoyarsk Territories. Previously published and new findings suggest that hantaviruses among shrews are widely distributed over the Russian Federation territory. The widespread circulation of SWSV and KKMV throughout Siberia is an important argument for investigation of their role in human infections

TO HANTAVIRUS INFECTION IN PEOPLE AND SMALL MAMMALS IN BAIKAL AREA

The article describes the results of recognaissance surveys of blood serums of humans in Baikal area for hantavirus antibodies and of tissue specimens (lungs) of small mammal for hantavirus antigens. This investigation demonstrated that Baikal area inhabitants contact such dangerous pathogens as hantaviruses. It's proved by the presence of hantavirus antibodies in human serum samples. IgG or IgM antibodies to hantaviruses were found in 3,7 % of 379 tested serum samples. IgM were found in 1,6 % of cases, IgG - in 2,1 % of cases. 2 patients with IgG and IgM with suspected traces of hantavirus infection had complaints to hyperthermia (up to 40,5 °C) and wasting. Blood serums with positive results of hantavirus antibodies were found in residents of Irkutsk region. Hantavirus antigens weren't found in researched lung samples of mouse-like rodent and insectivores from Angarsk, Irkutsk, Zalari and Ust-Kut districts of Irkutsk region and Tunkinsky district of Republic of Buryatia

Coronaviruses in rodents and insectivores in Altai Republic

Coronaviruses (family Coronaviridae, genera Alphacoronavirus, Betacoronavirus) are dangerous viral pathogens that have caused three outbreaks of severe respiratory diseases, SARS, MERS, COVID-19. In Russia, data on coronaviruses in natural reservoirs are limited, as investigations began only during the COVID-19 pandemic.The aim. To study the diversity of coronaviruses among rodents and insectivores in the Republic of Altai.Materials and methods. Rodents (n  =  67) and shrews (n  =  52) were captured in 2022. Samples were analyzed by reverse transcription-polymerase chain reaction followed by sequencing.Results and conclusions. Four samples from rodents (Myodes rutilus, M. glareolus, Apodemus peninsulae, A. agrarius) and two samples from an insectivore (Crocidura sibirica) were positive for coronaviruses, among which three different coronaviruses were detected. Rodent-borne coronaviruses are classified in the genus Betacoronavirus, subgenera Embecovirus, and have shown host associated clustering. The nucleotide sequences of Siberian coronaviruses from rodents were identical for closely related species (M. rutilus and M. glareolus, A. agrarius and A. peninsulae) and close (> 94 % homology) to previously published sequences in each of the groups of carriers found in the territory Novosibirsk region, Europe and China. The coronavirus identified from the insectivore, possibly belonging to a new subgenera of the family Coronaviridae, has also been assigned to the genus Betacoronavirus.Conclusion. Five species of natural carriers of three different coronaviruses were detected in the Altai Republic. A high level of identity of coronaviruses genomes from rodents has been revealed, indicating a relatively low rate of their evolution

Hantavirus Associated with Hemorrhagic Fever with Renal Syndrome Outbreak in the Saratov Region in 2019

Pathogenic hantaviruses, belonging to the family Hantaviridae, genus Orthohantavirus, are widely spread in many regions of the world and cause hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia. In the European Russia, the most active HFRS foci are located in the optimum habitat area of natural reservoir of the Puumala virus (PUUV), bank voles (Myodes glareolus), – in the Middle Volga and Cis-Urals. The largest number of cases of HFRS was registered in the Volga Federal District. In 2019, an outbreak of HFRS was registered among the residents of Saratov and the Saratov Region, the number of cases was 2702. Objective of the study was genetic identification of hantaviruses from HFRS patients and rodent carriers and phylogenetic analysis of full-size genomes from natural hosts during HFRS outbreak in the Saratov Region, 2019. Materials and methods. Blood samples of 8 HFRS patients from Saratov and 3 lung samples of bank voles captured in the suburb of Saratov were analyzed using reverse transcription polymerase chain reaction, followed by sequencing and phylogenetic analysis. Results and discussion. A total of 6 viral RNA isolates from HFRS patients were genetically typed, full-length RNA-isolate genomes were obtained for 3 natural carriers. Our data indicate that PUUV virus was associated with HFRS outbreak in Saratov. Genetic analysis revealed that the virus belonged to RUS lineage of PUUV, related most closely to strains from Udmurtia and Tatarstan and differed from strains circulating in the territory of Bashkortostan and Samara Region