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Psyrri A, Fayette J, Harrington K, Gillison M, Ahn MJ, Takahashi S, Weiss J, Machiels JP, Baxi S, Vasilyev A, Karpenko A, Dvorkin M, Hsieh CY, Thungappa SC, Segura PP, Vynnychenko I, Haddad R, Kasper S, Mauz PS, Baker V, He P, Evans B, Wildsmith S, Olsson RF, Yovine A, Kurland JF, Morsli N, Seiwert TY. Durvalumab with or without tremelimumab versus the EXTREME regimen as first-line treatment for recurrent or metastatic squamous cell carcinoma of the head and neck: KESTREL, a randomized, open-label, phase III study. Ann Oncol 2023; 34:262-274. [PMID: 36535565 DOI: 10.1016/j.annonc.2022.12.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 12/07/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Patients with recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) have a poor prognosis. The phase III KESTREL study evaluated the efficacy of durvalumab [programmed death-ligand 1 (PD-L1) antibody] with or without tremelimumab [cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) antibody], versus the EXTREME regimen in patients with R/M HNSCC. PATIENTS AND METHODS Patients with HNSCC who had not received prior systemic treatment for R/M disease were randomized (2 : 1 : 1) to receive durvalumab 1500 mg every 4 weeks (Q4W) plus tremelimumab 75 mg Q4W (up to four doses), durvalumab monotherapy 1500 mg Q4W, or the EXTREME regimen (platinum, 5-fluorouracil, and cetuximab) until disease progression. Durvalumab efficacy, with or without tremelimumab, versus the EXTREME regimen in patients with PD-L1-high tumors and in all randomized patients was assessed. Safety was also assessed. RESULTS Durvalumab and durvalumab plus tremelimumab were not superior to EXTREME for overall survival (OS) in patients with PD-L1-high expression [median, 10.9 and 11.2 versus 10.9 months, respectively; hazard ratio (HR) = 0.96; 95% confidence interval (CI) 0.69-1.32; P = 0.787 and HR = 1.05; 95% CI 0.80-1.39, respectively]. Durvalumab and durvalumab plus tremelimumab prolonged duration of response versus EXTREME (49.3% and 48.1% versus 9.8% of patients remaining in response at 12 months), correlating with long-term OS for responding patients; however, median progression-free survival was longer with EXTREME (2.8 and 2.8 versus 5.4 months). Exploratory analyses suggested that subsequent immunotherapy use by 24.3% of patients in the EXTREME regimen arm contributed to the similar OS outcomes between arms. Grade 3/4 treatment-related adverse events (TRAEs) for durvalumab, durvalumab plus tremelimumab, and EXTREME were 8.9%, 19.1%, and 53.1%, respectively. CONCLUSIONS In patients with PD-L1-high expression, OS was comparable between durvalumab and the EXTREME regimen. Durvalumab alone, and with tremelimumab, demonstrated durable responses and reduced TRAEs versus the EXTREME regimen in R/M HNSCC.
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Affiliation(s)
- A Psyrri
- Department of Internal Medicine, Section of Medical Oncology, Attikon University Hospital, National Kapodistrian University of Athens, Athens, Greece.
| | - J Fayette
- Centre de Lutte Contre le Cancer Léon Bérard, Lyon-I University, Lyon, France
| | - K Harrington
- Division of Radiotherapy and Imaging, The Royal Marsden/The Institute of Cancer Research NIHR Biomedical Research Centre, London, UK
| | - M Gillison
- Department of Thoracic Head and Neck Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, USA
| | - M-J Ahn
- Division of Hematology-Oncology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, South Korea
| | - S Takahashi
- Department of Medical Oncology, The Cancer Institute Hospital of the Japanese Foundation for Cancer Research, Tokyo, Japan
| | - J Weiss
- Division of Oncology, Department of Medicine, Lineberger Comprehensive Cancer Center at University of North Carolina, Chapel Hill, USA
| | - J-P Machiels
- Department of Medical Oncology, Institut Roi Albert II, Cliniques Universitaires Saint-Luc, Brussels; Institute for Experimental and Clinical Research (IREC, pôle MIRO), Université Catholique de Louvain (UCLouvain), Brussels, Belgium
| | - S Baxi
- Department of Medicine, Memorial Sloan Kettering Cancer Center, New York, USA
| | - A Vasilyev
- Department of General Physiology, Saint Petersburg State University, Saint Petersburg
| | - A Karpenko
- Department of Oncology, Leningrad Regional Oncology Dispensary, Saint Petersburg
| | - M Dvorkin
- Budgetary Institution of Healthcare, Omsk Regional Oncology Dispensary, Omsk, Russian Federation
| | - C-Y Hsieh
- Division of Hematology & Oncology, Department of Internal Medicine, China Medical University Hospital, Taichung City, Taiwan
| | - S C Thungappa
- Department of Medical Oncology, Healthcare Global Enterprises Limited, Bengaluru, Karnataka, India
| | - P P Segura
- Servicio de Oncología Médica, Hospital Clínico San Carlos, Madrid, Spain
| | - I Vynnychenko
- Sumy Regional Clinical Oncology Dispensary, Sumy State University, Sumy, Ukraine
| | - R Haddad
- Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, USA
| | - S Kasper
- Department of Medical Oncology, West German Cancer Center, University Hospital, Essen
| | - P-S Mauz
- Department of Otolaryngology, Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - V Baker
- Oncology R&D, Late-Stage Development, AstraZeneca, Cambridge, UK
| | - P He
- Statistics, AstraZeneca, Gaithersburg, USA
| | - B Evans
- Statistics, AstraZeneca, Gaithersburg, USA
| | - S Wildsmith
- Oncology R&D, Late-Stage Development, AstraZeneca, Cambridge, UK
| | - R F Olsson
- Oncology R&D, Late-Stage Development, AstraZeneca, Gothenburg, Sweden
| | - A Yovine
- Oncology R&D, Late-Stage Development, AstraZeneca, Cambridge, UK
| | - J F Kurland
- Oncology R&D, Late-Stage Development, AstraZeneca, Gaithersburg
| | - N Morsli
- Oncology R&D, Late-Stage Development, AstraZeneca, Cambridge, UK
| | - T Y Seiwert
- Department of Oncology, Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, USA.
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Govorov A, Shiryaev A, Vasilyev A, Pushkar D. Do bacteriophages really prevent urinary tract infections? Eur Urol 2021. [DOI: 10.1016/s0302-2838(21)00527-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Yarmoshenko I, Zhukovsky M, Onishchenko A, Vasilyev A, Malinovsky G. Factors influencing temporal variations of radon concentration in high-rise buildings. J Environ Radioact 2021; 232:106575. [PMID: 33711618 DOI: 10.1016/j.jenvrad.2021.106575] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 08/21/2020] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
Long-term radon time series were analyzed in 14 rooms and offices to search factors influencing indoor radon concentration in high-rise buildings. Radon entry to living rooms is determined both by diffusion from building materials and advection from adjoined low-ventilated spaces. Humans affect on seasonal and diurnal radon concentration changes in high-rise buildings by activating ventilation system. Indoor-outdoor temperature difference significantly influence on the air exchange rate under uncontrolled ventilation, which is especially important in new energy efficient buildings.
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Affiliation(s)
- I Yarmoshenko
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russia.
| | - M Zhukovsky
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russia
| | - A Onishchenko
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russia
| | - A Vasilyev
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russia
| | - G Malinovsky
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russia
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Vasilyev A, Yarmoshenko I, Onishchenko A, Hoffmann M, Malinovsky G, Marenny A, Karl L. RADON MEASUREMENTS IN BIG BUILDINGS: PILOT STUDY IN RUSSIA. Radiat Prot Dosimetry 2020; 191:214-218. [PMID: 33130857 DOI: 10.1093/rpd/ncaa150] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Detailed analysis of indoor radon concentration distribution by floors was conducted in four children institutions, one office building and two residential houses in Russian cities to develop approaches to draw up a program of radon survey for big buildings. Higher variability of radon concentration was found in high geogenic radon potential (GRP) area when the soil is the main source of radon. No essential dependence of radon concentration on the floor in high-rise buildings was found in low GRP area. The number of required radon measurements is estimated using obtained characteristics of radon variability.
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Affiliation(s)
- A Vasilyev
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russian Federation
| | - I Yarmoshenko
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russian Federation
| | - A Onishchenko
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russian Federation
| | - M Hoffmann
- University of Applied Sciences and Arts of Southern Switzerland, SUPSI, Lugano, Switzerland
| | - G Malinovsky
- Institute of Industrial Ecology UB RAS, Ekaterinburg, Russian Federation
| | - A Marenny
- Research and Technical Center of Radiation-Chemical Safety and Hygiene FMBA, Moscow, Russia
| | - L Karl
- Research and Technical Center of Radiation-Chemical Safety and Hygiene FMBA, Moscow, Russia
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Yarmoshenko I, Onishchenko A, Malinovsky G, Vasilyev A. RADON TIME SERIES IN FOUR FLATS IN ENERGY EFFICIENT MULTI-STOREY BUILDING. Radiat Prot Dosimetry 2020; 191:228-232. [PMID: 33123729 DOI: 10.1093/rpd/ncaa158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Influence of living habits and meteorological parameters on indoor radon concentration in a new energy efficiency multi-storey flat building typical for Russian cities was studied using radon time series analysis. Continuous indoor radon measurements were conducted in four flats of the same multi-storey residential building in Ekaterinburg, Russia. Factors influencing indoor radon in surveyed building (by rank) are as follows: ventilation regime> indoor/outdoor temperature difference > wind direction. Intentional ventilation frequency, temperature difference and wind direction explain together up to 46% of indoor radon variability in a flat of multi-storey building.
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Affiliation(s)
- I Yarmoshenko
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - A Onishchenko
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - G Malinovsky
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - A Vasilyev
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
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Vasilyev A, Pavlova T. [IATROGENIC INJURIES DURING PREOPERATIVE MARKING OF NON-PALPABLE PATHOLOGICAL AREAS OF THE MAMMARY GLANDS]. Georgian Med News 2020:30-34. [PMID: 33270573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The purpose of the study is to identify the types and frequency of medical mistakes made during preoperative marking of non - palpable pathological areas of the breast. We analyzed 60 clinical observations of patients with non-palpable, morphologically verified pathological areas in breast tissues, who underwent surgical intervention at the first stage of treatment with mandatory preoperative marking with a guide needle. The obtained data indicates that the error rate of radiologists when installing a tissue marker in a non-palpable breast neoplasm is 13.3% and is most often manifested by syntopia of the guide needle, which is detected at the beginning of the operation and requires implantation of additional tags. All clinical observations were accompanied by an increase in both the equivalent dose received by the patient and duration of the anesthesia. To improve the quality of interventional techniques performed on the breast, also to minimize the number of iatrogenic injuries, the radiologist must have spatial thinking, a sufficient amount of theoretical knowledge and practical skills.
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Affiliation(s)
- A Vasilyev
- 1Central Research Institute of Radiation Diagnostics; 2Moscow State University of Medicine and Dentistry named after A. I. Evdokimov; Russia
| | - T Pavlova
- 1Central Research Institute of Radiation Diagnostics; 3City Clinical Hospital named after V. Buyanov, Moscow, Russia
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Popova A, Rogovaya O, Artyuhov A, Evtushenko N, Ismaylova L, Vasilyev A, Vorotelyak E. Influence of cryostorage on stem cell population in human keratinocytes. Cytotherapy 2020. [DOI: 10.1016/j.jcyt.2020.03.367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Engels R, Grigoryev K, Kannis CS, Michael Y, Ströher H, Verhoeven V, Büscher M, Huxold L, Kochenda L, Kravtsov P, Trofimov V, Vasilyev A, Vznuzdaev M. Production of HD Molecules in Definite Hyperfine Substates. Phys Rev Lett 2020; 124:113003. [PMID: 32242681 DOI: 10.1103/physrevlett.124.113003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 02/02/2020] [Indexed: 06/11/2023]
Abstract
Polarized atomic beam sources have been in operation for many years to produce either nuclear polarized atomic hydrogen or deuterium beams. In recent experiments, such a source was used to polarize both isotopes independently at the same time. By recombination of the atoms, hydrogen-deuterium molecules with all possible nuclear spin combinations can be created. Those spin isomers are useful for further applications, like precision spectroscopy, as polarized targets for laser-particle acceleration, polarized fuel for fusion reactors, or as an option for future measurements of electric dipole moments.
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Affiliation(s)
- R Engels
- Institute for Nuclear Physics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - K Grigoryev
- Institute for Nuclear Physics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - C S Kannis
- Institute for Nuclear Physics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - Y Michael
- Institute for Nuclear Physics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - H Ströher
- Institute for Nuclear Physics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - V Verhoeven
- Institute for Nuclear Physics, Forschungszentrum Jülich, 52425 Jülich, Germany
| | - M Büscher
- Peter Grünberg Institute, Forschungszentrum Jülich, 52425 Jülich, Germany and Institute for Laser- and Plasma-Physics, Heinrich-Heine Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - L Huxold
- Institute for Laser- and Plasma-Physics, Heinrich-Heine Universität Düsseldorf, 40225 Düsseldorf, Germany
| | - L Kochenda
- 'Kurchatov Institute' B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - P Kravtsov
- 'Kurchatov Institute' B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - V Trofimov
- 'Kurchatov Institute' B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - A Vasilyev
- 'Kurchatov Institute' B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - M Vznuzdaev
- 'Kurchatov Institute' B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
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Vasilyev A, Hansard M. Spatial Distribution of Eye-Movements After Central Vision Loss is Consistent with an Optimal Visual Search Strategy. Int J Neural Syst 2019; 29:1950026. [PMID: 31711331 DOI: 10.1142/s0129065719500266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The problem of gaze allocation has previously been studied in the framework of eye-movement control models, which require prior knowledge of visibility maps (VMs). These encode the signal-to-noise ratio, at each point in the visual field, which can be used to define an optimal policy of gaze allocation. However, it is not always possible to estimate the VM, in a given experimental setting, as it depends on many factors, including the visual system of the individual observer. Hence, few eye-movement datasets include the corresponding VM estimates. This can be problematic for the analysis of certain clinical conditions, such as Age-related Macular Degeneration (AMD), which are associated with reduced sensitivity in the affected locations of the visual field. The corresponding VMs are highly idiosyncratic, and cannot be modeled by estimates obtained from healthy observers. We propose an algorithm for maximum likelihood VM estimation, working directly from eye-movement sequences. We apply this algorithm to two eye-tracking datasets, based on visual search tasks, obtained from AMD patients. We show that the inferred VMs are spatially consistent with the measured visual field sensitivities. We also show that simulations with the estimated VMs can account for the asymmetric distribution of saccade vectors, which is typical of AMD patients.
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Affiliation(s)
- A Vasilyev
- School of EECS, Queen Mary University of London, London E1 4NS, UK
| | - M Hansard
- School of EECS, Queen Mary University of London, London E1 4NS, UK
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Zhukovsky M, Vasyanovich M, Onishchenko A, Vasilyev A. Anomalously high unattached fraction of 220Rn decay products in the atmosphere of monazite storage facility. Appl Radiat Isot 2019; 151:1-6. [DOI: 10.1016/j.apradiso.2019.05.035] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 05/23/2019] [Accepted: 05/24/2019] [Indexed: 10/26/2022]
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11
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Zhukovsky M, Vasilyev A, Onishchenko A, Yarmoshenko I. REVIEW OF INDOOR RADON CONCENTRATIONS IN SCHOOLS AND KINDERGARTENS. Radiat Prot Dosimetry 2018; 181:6-10. [PMID: 29897581 DOI: 10.1093/rpd/ncy092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 05/23/2018] [Indexed: 06/08/2023]
Abstract
Analysis includes review of 63 national and regional indoor radon surveys in kindergartens and schools. Preliminary assessment of the worldwide population weighted characteristics of radon concentration in children's institutions is: arithmetic mean = 59 and geometric mean = 36 Bq/m3. Higher indoor radon concentrations in children's institutions in comparison with the dwellings can be explained by characteristics of ventilation, attendance regime and construction features. Special protocol of measurements in the kindergartens and schools is required.
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Affiliation(s)
- M Zhukovsky
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy Street 20, Ekaterinburg, Russian Federation
| | - A Vasilyev
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy Street 20, Ekaterinburg, Russian Federation
| | - A Onishchenko
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy Street 20, Ekaterinburg, Russian Federation
| | - I Yarmoshenko
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy Street 20, Ekaterinburg, Russian Federation
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Onishchenko A, Malinovsky G, Vasilyev A, Zhukovsky M. RADON MEASUREMENTS IN KINDERGARTENS IN URAL REGION (RUSSIA). Radiat Prot Dosimetry 2017; 177:112-115. [PMID: 29036708 DOI: 10.1093/rpd/ncx156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The radon survey of kindergartens has been conducted in Sverdlovskaya oblast during 2013-16. Indoor radon concentrations have been measured in 180 kindergartens in 21 villages and 10 towns. The LR-115 nuclear track detectors were placed in 560 rooms (three or four rooms per kindergarten) during 2-3 months. To obtain annual values, radon measurements were carried in the cold and warm seasons. The arithmetic and geometric means of annual indoor radon concentrations in rooms are 59 and 42 Bq/m3 respectively, GSD = 2.33. Analysis of the building factors affecting radon entry is presented. The detailed radon survey was performed in one kindergarten where exceeding of national action radon level was observed.
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Affiliation(s)
- A Onishchenko
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, 620990 Ekaterinburg, Russia
| | - G Malinovsky
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, 620990 Ekaterinburg, Russia
| | - A Vasilyev
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, 620990 Ekaterinburg, Russia
| | - M Zhukovsky
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy St., 20, 620990 Ekaterinburg, Russia
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Yarmoshenko I, Onishchenko A, Malinovsky G, Vasilyev A, Zhukovsky M. COMPARISON OF APPROACHES TO OBTAIN A SAMPLE OF DWELLINGS FOR RADON SURVEY. Radiat Prot Dosimetry 2017; 177:91-94. [PMID: 29036686 DOI: 10.1093/rpd/ncx166] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Obtaining of the representative sample of dwellings is a basic requirement to organization of the radon survey. Since random selection is often impossible, quasi-random approaches are used. The aim of the study is to analyze errors in radon exposure assessment that resulted from rejecting the random selection. Both the modeling and experiments were conducted. Three types of errors were observed: shifting of the mean, change of the variance and mixture of the previous two.
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Affiliation(s)
- I Yarmoshenko
- IIE UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - A Onishchenko
- IIE UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - G Malinovsky
- IIE UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - A Vasilyev
- IIE UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
| | - M Zhukovsky
- IIE UB RAS, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
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Vasilyev A, Yarmoshenko I. Effect of energy-efficient measures in building construction on indoor radon in Russia. Radiat Prot Dosimetry 2017; 174:419-422. [PMID: 27358394 DOI: 10.1093/rpd/ncw149] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Accepted: 03/06/2016] [Indexed: 06/06/2023]
Abstract
The effect of implementation of energy-efficient measures in building construction was studied. Analysis includes study of indoor radon in energy-efficient buildings in Ekaterinburg, Russia, and results of radiation measurements in 83 regions of Russia conducted within the regional programmes. The forecast distribution of radon concentration in Ekaterinburg was built with regard to the city development programme. With Ekaterinburg taken as representative case, forecast distribution of radon concentration in Russia in 2030 was built. In comparison with 2000, average radon concentration increases by a factor of 1.42 in 2030 year; percentage above the reference level 300 Bq/m3 increases by a factor of 4 in 2030 year. It is necessary to perceive such an increase with all seriousness and to prepare appropriate measures for optimization of protection against indoor radon. Despite the high uncertainty, reconstructed distribution of radon concentration can be applied for justification of measures to be incorporated in the radon mitigation strategy.
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Affiliation(s)
- A Vasilyev
- IIE UB RAS, SophyKovalevskoyst. 20, Ekaterinburg 620990, Russia
| | - I Yarmoshenko
- IIE UB RAS, SophyKovalevskoyst. 20, Ekaterinburg 620990, Russia
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Krakhotkin D, Ibishev K, Vasilyev A, Amirbekov B, Ibisheva A. P-01-053 Deficiency of testosterone in patients with post-traumatic urethral stricture. J Sex Med 2017. [DOI: 10.1016/j.jsxm.2017.03.182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Krakhotkin D, Ibishev K, Vasilyev A, Kogan M, Magomedov R. HP-04-004 Evaluation of immunological parameters of prostatic secretion in chronic recurrent bacterial prostatitis. J Sex Med 2017. [DOI: 10.1016/j.jsxm.2017.03.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Lozhkin V, Tarkhov D, Timofeev V, Lozhkina O, Vasilyev A. Differential neural network approach in information process for prediction of roadside air pollution by peat fire. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1757-899x/158/1/012063] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Lozhkina O, Lozhkin V, Nevmerzhitsky N, Tarkhov D, Vasilyev A. Motor transport related harmful PM2.5 and PM10: from onroad measurements to the modelling of air pollution by neural network approach on street and urban level. ACTA ACUST UNITED AC 2016. [DOI: 10.1088/1742-6596/772/1/012031] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Yarmoshenko I, Malinovsky G, Vasilyev A, Onischenko A, Seleznev A. Geogenic and anthropogenic impacts on indoor radon in the Techa River region. Sci Total Environ 2016; 571:1298-1303. [PMID: 27474991 DOI: 10.1016/j.scitotenv.2016.07.170] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/05/2016] [Revised: 07/06/2016] [Accepted: 07/23/2016] [Indexed: 06/06/2023]
Abstract
Indoor radon concentration was studied in the 14 settlements located near the Techa River, which was contaminated by radioactive wastes in 1950-s. Results of the radon survey were used for analysis of the relationship between the indoor radon and main geologic factors (Pre-Jurassic formations, Quaternary sediments and faults), local geogenic radon potential and anthropogenic factors. Main influencing factors explain 58% of the standard deviation of indoor radon concentration. Association of the air exchange influence over radon concentration with underlying geological media was related to different contributions of geogenic advective and diffusive radon entries. The properties of geological formation to transfer radon gas in interaction with the house can be considered within the radon geogenic potential concept. The study of the radon exposure of the Techa River population can be used to estimate the contribution of natural radon to the overall radiation exposure of the local population during the period of radioactive waste discharges.
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Affiliation(s)
- I Yarmoshenko
- IIE UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia.
| | - G Malinovsky
- IIE UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
| | - A Vasilyev
- IIE UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
| | - A Onischenko
- IIE UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
| | - A Seleznev
- IIE UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
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Lapshina S, Myasoutova L, Erdes S, Mukhina R, Vasilyev A. AB0719 The Effectiveness of Therapeutic Strategies To Achieve The Goal (T2T) on The Example of Kazan (Russia) Cohort of Patients with Spondyloarthritis. Ann Rheum Dis 2016. [DOI: 10.1136/annrheumdis-2016-eular.5752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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21
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Yarmoshenko I, Vasilyev A, Malinovsky G, Bossew P, Žunić ZS, Onischenko A, Zhukovsky M. Variance of indoor radon concentration: Major influencing factors. Sci Total Environ 2016; 541:155-160. [PMID: 26409145 DOI: 10.1016/j.scitotenv.2015.09.077] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 08/25/2015] [Accepted: 09/15/2015] [Indexed: 06/05/2023]
Abstract
Variance of radon concentration in dwelling atmosphere is analysed with regard to geogenic and anthropogenic influencing factors. Analysis includes review of 81 national and regional indoor radon surveys with varying sampling pattern, sample size and duration of measurements and detailed consideration of two regional surveys (Sverdlovsk oblast, Russia and Niška Banja, Serbia). The analysis of the geometric standard deviation revealed that main factors influencing the dispersion of indoor radon concentration over the territory are as follows: area of territory, sample size, characteristics of measurements technique, the radon geogenic potential, building construction characteristics and living habits. As shown for Sverdlovsk oblast and Niška Banja town the dispersion as quantified by GSD is reduced by restricting to certain levels of control factors. Application of the developed approach to characterization of the world population radon exposure is discussed.
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Affiliation(s)
- I Yarmoshenko
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia.
| | - A Vasilyev
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
| | - G Malinovsky
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
| | - P Bossew
- German Federal Office for Radiation Protection (BfS), Berlin, Germany
| | - Z S Žunić
- Institute of Nuclear Sciences "Vinca", University of Belgrade, Serbia
| | - A Onischenko
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
| | - M Zhukovsky
- Institute of Industrial Ecology UB RAS, Sophy Kovalevskoy, 20, Ekaterinburg, Russia
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22
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Yarmoshenko I, Malinovsky G, Vasilyev A, Zhukovsky M. Reconstruction of national distribution of indoor radon concentration in Russia using results of regional indoor radon measurement programs. J Environ Radioact 2015; 150:99-103. [PMID: 26313426 DOI: 10.1016/j.jenvrad.2015.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Revised: 08/06/2015] [Accepted: 08/15/2015] [Indexed: 06/04/2023]
Abstract
The aim of the paper is a reconstruction of the national distribution and estimation of the arithmetic average indoor radon concentration in Russia using the data of official annual 4-DOZ reports. Annual 4-DOZ reports summarize results of radiation measurements in 83 regions of Russian Federation. Information on more than 400,000 indoor radon measurements includes the average indoor radon isotopes equilibrium equivalent concentration (EEC) and number of measurements by regions and by three main types of houses: wooden, one-storey non-wooden, and multi-storey non-wooden houses. To reconstruct the national distribution, all-Russian model sample was generated by integration of sub-samples created using the results of each annual regional program of indoor radon measurements in each type of buildings. According to indoor radon concentration distribution reconstruction, all-Russian average indoor radon concentration is 48 Bq/m(3). Average indoor radon concentration by region ranges from 12 to 207 Bq/m(3). The 95-th percentile of the distribution is reached at indoor radon concentration 160 Bq/m(3).
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Affiliation(s)
- I Yarmoshenko
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy St., 20, Ekaterinburg 620219, Russia.
| | - G Malinovsky
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy St., 20, Ekaterinburg 620219, Russia
| | - A Vasilyev
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy St., 20, Ekaterinburg 620219, Russia
| | - M Zhukovsky
- Institute of Industrial Ecology UB RAS, S. Kovalevskoy St., 20, Ekaterinburg 620219, Russia
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23
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Alekseev I, Arkhipov E, Bondarenko S, Fedorchenko O, Ganzha V, Ivshin K, Kammel P, Kravtsov P, Petitjean C, Trofimov V, Vasilyev A, Vasyanina T, Vorobyov A, Vznuzdaev M. Cryogenic distillation facility for isotopic purification of protium and deuterium. Rev Sci Instrum 2015; 86:125102. [PMID: 26724068 DOI: 10.1063/1.4936413] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Isotopic purification of the protium and deuterium is an important requirement of many physics experiments. A cryogenic facility for high-efficiency separation of hydrogen isotopes with a cryogenic distillation column as the main element is described. The instrument is portable, so that it can be used at the experimental site. It was designed and built at the Petersburg Nuclear Physics Institute, Gatchina, Russia. Fundamental operating parameters have been measured including a liquid holdup in the column packing, the pressure drops across the column and the purity of the product at different operating modes. A mathematical model describes expected profiles of hydrogen isotope concentration along the distillation column. An analysis of ortho-parahydrogen isomeric composition by gas chromatography was used for evaluation of the column performance during the tuning operations. The protium content during deuterium purification (≤100 ppb) was measured using gas chromatography with accumulation of the protium in the distillation column. A high precision isotopic measurement at the Institute of Particle Physics, ETH-Zurich, Switzerland, provided an upper bound of the deuterium content in protium (≤6 ppb), which exceeds all commercially available products.
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Affiliation(s)
- I Alekseev
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - Ev Arkhipov
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - S Bondarenko
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - O Fedorchenko
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - V Ganzha
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - K Ivshin
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - P Kammel
- Department of Physics, University of Washington, Seattle, Washington 98195, USA
| | - P Kravtsov
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - C Petitjean
- Paul Scherrer Institut (PSI), CH-5232 Villigen, Switzerland
| | - V Trofimov
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - A Vasilyev
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - T Vasyanina
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - A Vorobyov
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
| | - M Vznuzdaev
- National Research Center "Kurchatov Institute" Petersburg Nuclear Physics Institute (NRC "Kurchatov Institute" PNPI), 188300 Gatchina, Russia
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Engels R, Gaißer M, Gorski R, Grigoryev K, Mikirtychyants M, Nass A, Rathmann F, Seyfarth H, Ströher H, Weiss P, Kochenda L, Kravtsov P, Trofimov V, Tschernov N, Vasilyev A, Vznuzdaev M, Schieck HPG. Production of hyperpolarized H_{2} molecules from H[over →] atoms in gas-storage cells. Phys Rev Lett 2015; 115:113007. [PMID: 26406831 DOI: 10.1103/physrevlett.115.113007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Indexed: 06/05/2023]
Abstract
The preservation of the nuclear polarization of hydrogen atoms during the recombination to molecules was observed on different surface materials in the temperature range from 45 to 100 K and for magnetic fields up to 1 T. On a gold and a fused quartz surface, the expected molecular polarization of about 50% or lower of the atomic polarization was measured, while a surface layer of perfluoropolyether (Fomblin) shows a nearly complete preservation (at least 97%) of the atomic polarization during the recombination process. Further experiments have the possibility of storing polarized deuterium molecules and to use them in nuclear-fusion installations. Another application might be the production of polarized substances for enhanced NMR techniques.
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Affiliation(s)
- R Engels
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - M Gaißer
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - R Gorski
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - K Grigoryev
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - M Mikirtychyants
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - A Nass
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - F Rathmann
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - H Seyfarth
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - H Ströher
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - P Weiss
- Institut für Kernphysik, Forschungszentrum Jülich, 52428 Jülich, Germany
| | - L Kochenda
- Laboratory of Cryogenic and Superconductive Techniques, National Research Centre "Kurchatov Institute" B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - P Kravtsov
- Laboratory of Cryogenic and Superconductive Techniques, National Research Centre "Kurchatov Institute" B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - V Trofimov
- Laboratory of Cryogenic and Superconductive Techniques, National Research Centre "Kurchatov Institute" B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - N Tschernov
- Laboratory of Cryogenic and Superconductive Techniques, National Research Centre "Kurchatov Institute" B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - A Vasilyev
- Laboratory of Cryogenic and Superconductive Techniques, National Research Centre "Kurchatov Institute" B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
| | - M Vznuzdaev
- Laboratory of Cryogenic and Superconductive Techniques, National Research Centre "Kurchatov Institute" B. P. Konstantinov Petersburg Nuclear Physics Institute (PNPI), 188300 Gatchina, Russia
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25
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Zhukovsky M, Bastrikova N, Vasilyev A. Relative biological effectiveness of alpha particles at radon exposure. Radiat Prot Dosimetry 2015; 164:467-470. [PMID: 25979745 DOI: 10.1093/rpd/ncv334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The relative biological effectiveness (RBE) of alpha particles at radon exposure is estimated by comparison of radiation risks at external gamma exposure and radon exposure in different situations. For external gamma exposure, the BEIR VII model of radiation risk assessment was used. For occupational and indoor radon exposure, models such as BEIR VI, WISMUT, Tomasek's and combined miners population were considered. It was demonstrated that RBE values are strongly dependent on models of radiation risk assessment used for RBE calculation, sex of exposed peoples and age at the exposure. The average values of RBE in dependence on model of risk assessment choice are in the range from 1.5 to 12.0 for males and in the range from 0.34 to 2.7 for females.
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Affiliation(s)
- M Zhukovsky
- Institute of Industrial Ecology, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia Ural Federal University, Mira St., 19, Ekaterinburg 620002, Russia
| | - N Bastrikova
- Ural Federal University, Mira St., 19, Ekaterinburg 620002, Russia
| | - A Vasilyev
- Institute of Industrial Ecology, Sophy Kovalevskoy St., 20, Ekaterinburg 620990, Russia
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26
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Vasilyev A, Abdulganieva D, Lapshina S, Myasoutova L. AB0886 Comparative Characteristics of the Change in Bone Mineral Density in Patients with Rheumatoid Arthritis and Ankylosing Spondylitis. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.4499] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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27
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Myasoutova L, Vasilyev A, Abdulganieva D, Lapshina S. AB0887 Influence of Bone Mineral Density at the Femoral Neck on the Probability of Osteoporotic Fractures. Ann Rheum Dis 2015. [DOI: 10.1136/annrheumdis-2015-eular.4366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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28
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Myasoutova L, Lapshina S, Vasilyev A. AB1009 Patients with rheumatic diseases are at risk of osteoporosis development. Ann Rheum Dis 2013. [DOI: 10.1136/annrheumdis-2012-eular.1009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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29
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White JO, Vasilyev A, Cahill JP, Satyan N, Okusaga O, Rakuljic G, Mungan CE, Yariv A. Suppression of stimulated Brillouin scattering in optical fibers using a linearly chirped diode laser. Opt Express 2012; 20:15872-15881. [PMID: 22772277 DOI: 10.1364/oe.20.015872] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The output of high power fiber amplifiers is typically limited by stimulated Brillouin scattering (SBS). An analysis of SBS with a chirped pump laser indicates that a chirp of 2.5 × 10(15) Hz/s could raise, by an order of magnitude, the SBS threshold of a 20-m fiber. A diode laser with a constant output power and a linear chirp of 5 × 10(15) Hz/s has been previously demonstrated. In a low-power proof-of-concept experiment, the threshold for SBS in a 6-km fiber is increased by a factor of 100 with a chirp of 5 × 10(14) Hz/s. A linear chirp will enable straightforward coherent combination of multiple fiber amplifiers, with electronic compensation of path length differences on the order of 0.2 m.
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Affiliation(s)
- J O White
- U.S. Army Research Laboratory, 2800 Powder Mill Road, Adelphi, Maryland 20783, USA.
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30
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Seyfarth H, Engels R, Rathmann F, Ströher H, Baryshevsky V, Rouba A, Düweke C, Emmerich R, Imig A, Grigoryev K, Mikirtychiants M, Vasilyev A. Production of a beam of tensor-polarized deuterons using a carbon target. Phys Rev Lett 2010; 104:222501. [PMID: 20867161 DOI: 10.1103/physrevlett.104.222501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2009] [Indexed: 05/29/2023]
Abstract
An initially unpolarized beam of deuterons is found to acquire tensor polarization after traversing a foil of spin-zero target nuclei. The effect, called nuclear spin dichroism, has been predicted theoretically, albeit resulting in small values of p(zz) of the order of 0.01 for energies around 10 MeV. The experiment was carried out at the Köln tandem accelerator using carbon targets bombarded by deuterons. The observed polarization is as large as p(zz)=-0.28±0.03 for a beam of 14.8 MeV and a 129 mg/cm2 target. The results allow one to produce tensor-polarized deuterons with p(zz) around -0.30 (or +0.25) from an initially unpolarized beam using a carbon target of appropriate thickness.
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Affiliation(s)
- H Seyfarth
- Institut für Kernphysik, Jülich Center for Hadron Physics, Forschungszentrum Jülich, Leo-Brandt-Straße 1, D-52425 Jülich, Germany.
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31
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Alekseev I, Fedorchenko O, Kravtsov P, Vasilyev A, Vznuzdaev M. Experimental Results of Hydrogen Distillation at the Low Power Cryogenic Column for the Production of Deuterium Depleted Hydrogen. Fusion Science and Technology 2008. [DOI: 10.13182/fst08-a1841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- I. Alekseev
- Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300, RUSSIA. E-mail:
| | - O. Fedorchenko
- Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300, RUSSIA. E-mail:
| | - P. Kravtsov
- Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300, RUSSIA. E-mail:
| | - A. Vasilyev
- Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300, RUSSIA. E-mail:
| | - M. Vznuzdaev
- Petersburg Nuclear Physics Institute, Gatchina, Leningrad district, 188300, RUSSIA. E-mail:
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Vasilyev A, Khater K, Rakowski R. Effect of extracellular pH on presteady-state and steady-state current mediated by the Na+/K+ pump. J Membr Biol 2004; 198:65-76. [PMID: 15138746 PMCID: PMC1357233 DOI: 10.1007/s00232-004-0660-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 01/10/2004] [Indexed: 01/29/2023]
Abstract
A ouabain sensitive inward current occurs in Xenopus oocytes in Na+ and K(+)-free solutions. Several laboratories have investigated the properties of this current and suggested that acidic extracellular pH (pHo) produces a conducting pathway through the Na+/K+ pump that is permeable to H+ and blocked by [Na+]o. An alternative suggestion is that the current is mediated by an electrogenic H(+)-ATPase. Here we investigate the effect of pHo and [Na+]o on both transient and steady-state ouabain-sensitive current. At alkaline or neutral pHo the relaxation rate of pre-steady-state current is an exponential function of voltage. Its U-shaped voltage dependence becomes apparent at acidic pHo, as predicted by a model in which protonation of the Na+/K+ pump reduces the energy barrier between the internal solution and the Na+ occluded state. The model also predicts that acidic pHo increases steady-state current leak through the pump. The apparent pK of the titratable group(s) is approximately 6, suggesting that histidine is involved in induction of the conductance pathway. 22Na efflux experiments in squid giant axon and current measurements in oocytes at acidic pHo suggest that both Na+ and H+ are permeant. The acid-induced inward current is reduced by high [Na+]o, consistent with block by Na+. A least squares analysis predicts that H+ is four orders of magnitude more permeant than Na+, and that block occurs when 3 Na+ ions occupy a low affinity binding site (K(0.5) = 130 +/- 30 m M) with a dielectric coefficient of 0.23 +/- 0.03. These data support the conclusion that the ouabain-sensitive conducting pathway is a result of passive leak of both Na+ and H+ through the Na+/K+ pump.
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Affiliation(s)
- A. Vasilyev
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science/The Chicago Medical School, North Chicago, IL, 60064, USA
| | - K. Khater
- Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science/The Chicago Medical School, North Chicago, IL, 60064, USA
| | - R.F. Rakowski
- Department of Biological Sciences, Ohio University, Athens, OH 45701, USA
- Correspondence to: R.F.Rakowski;
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Abstract
External potassium (K) activates the inward rectifier ROMK (K(ir)1.1) by altering the pH gating of the channel. The present study examines this link between external K and internal pH sensitivity using both the two-electrode voltage clamp and the perfused, cut-open Xenopus oocyte preparation. Elevating extracellular K from 1 mM to 10 mM to 100 mM activated ROMK channels by shifting their apparent pK(a) from 7.2 +/- 0.1 (n = 6) in 1 mM K, to 6.9 +/- 0.02 (n = 5) in 10 mM K, and to 6.6 +/- 0.03 (n = 5) in 100 mM K. At any given internal pH, the number of active ROMK channels is a saturating function of external [K]. Extracellular Cs (which blocks almost all inward K current) also stimulated outward ROMK conductance (at constant 1 mM external K) by shifting the apparent pK(a) of ROMK from 7.2 +/- 0.1 (n = 6) in 1 mM K to 6.8 +/- 0.01 (n = 4) in 1 mM K + 104 mM Cs. Surprisingly, the binding and washout of the specific blocker, Tertiapin-Q, also activated ROMK in 1 mM K and caused a comparable shift in apparent pK(a). These results are interpreted in terms of both a three-state kinetic model and a two-gate structural model that is based on results with KcsA in which the selectivity filter can assume either a high or low K conformation. In this context, external K, Cs, and Tertiapin-Q activate ROMK by destabilizing the low-K (collapsed) configuration of the selectivity filter.
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Affiliation(s)
- H Sackin
- Department of Physiology and Biophysics, The Chicago Medical School, North Chicago, Illinois 60064, USA.
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34
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Vasilyev A, Indyk E, Rakowski RF. Properties of a sodium channel (Na(x)) activated by strong depolarization of Xenopus oocytes. J Membr Biol 2002; 185:237-47. [PMID: 11891581 DOI: 10.1007/s00232-001-0126-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2001] [Indexed: 11/24/2022]
Abstract
Short (<1 sec) duration depolarization of Xenopus laevis oocytes to voltages greater than +40 mV activates a sodium-selective channel (Na(x)) with sodium permeability five to six times greater than the permeability of other monovalent cations examined, including K+, Rb+, Cs+, TMA+, and Choline+. The permeability to Li+ is about equal to that of Na+. This channel was present in all oocytes examined. The kinetics, voltage dependence and pharmacology of Na(x)distinguish it from TTX-sensitive or epithelial sodium channels. It is also different from the sodium channel of Xenopus oocytes activated by prolonged depolarization, which is more highly selective for Na+, requires prolonged depolarization to be activated, and is blocked by Li+. Intracellular Mg2+ reversibly inhibits Na(x), whereas extracellular Mg2+ does not have an inhibitory effect. Intracellular Mg2+ inhibition of Na(x), is voltage dependent, suggesting that Mg2+ binding occurs within the membrane field. Eosin is also a reversible voltage-dependent intracellular inhibitor of Na(x), suggesting that a P-type ATPase may mediate the current. An additional cytoplasmic factor is involved in maintaining Na(x) since the current runs down in internally perfused oocytes and excised membrane patches. The rundown is reversible by reintroduction of the membrane patch into oocyte cytoplasm. The cytoplasmic factor is not ATP, because ATP has no effect on Na(x) current magnitude in either cut-open or inside-out patch preparations. Extracellular Gd3+ is also an inhibitor of Na(x). Na(x) activation follows a sigmoid time course. Its half-maximal activation potential is +100 mV and the effective valence estimated from the steepness of conductance activation is 1.0. Na(x) deactivates monoexponentially upon return to the holding potential (-40 mV). The deactivation rate is voltage dependent, increasing at more negative membrane potentials.
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Affiliation(s)
- A Vasilyev
- Department of Physiology and Biophysics, Finch University of Health Sciences/The Chicago Medical School, North Chicago, IL 60064, USA
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