56 results on '"Andrei A. Zaitsev"'
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2. The Copper Reduction Potential Determines the Reductive Cytotoxicity: Relevance to the Design of Metal–Organic Antitumor Drugs
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Elena K. Beloglazkina, Anna A. Moiseeva, Sergey A. Tsymbal, Dmitry A. Guk, Mikhail A. Kuzmin, Olga O. Krasnovskaya, Roman S. Borisov, Elena S. Barskaya, Victor A. Tafeenko, Victoria M. Alpatova, Andrei V. Zaitsev, Alexander V. Finko, Valentina A. Ol’shevskaya, and Alexander A. Shtil
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copper ,redox reactions ,electrochemistry ,tumor cells ,cytotoxicity ,medicinal chemistry ,Organic chemistry ,QD241-441 - Abstract
Copper–organic compounds have gained momentum as potent antitumor drug candidates largely due to their ability to generate an oxidative burst upon the transition of Cu2+ to Cu1+ triggered by the exogenous-reducing agents. We have reported the differential potencies of a series of Cu(II)–organic complexes that produce reactive oxygen species (ROS) and cell death after incubation with N-acetylcysteine (NAC). To get insight into the structural prerequisites for optimization of the organic ligands, we herein investigated the electrochemical properties and the cytotoxicity of Cu(II) complexes with pyridylmethylenethiohydantoins, pyridylbenzothiazole, pyridylbenzimidazole, thiosemicarbazones and porphyrins. We demonstrate that the ability of the complexes to kill cells in combination with NAC is determined by the potential of the Cu+2 → Cu+1 redox transition rather than by the spatial structure of the organic ligand. For cell sensitization to the copper–organic complex, the electrochemical potential of the metal reduction should be lower than the oxidation potential of the reducing agent. Generally, the structural optimization of copper–organic complexes for combinations with the reducing agents should include uncharged organic ligands that carry hard electronegative inorganic moieties.
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- 2024
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3. Results of a clinical study of the drug efficacy and safety for intravesical administration based on bacteriophages in therapy in patients with chronic recurrent cystitis
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Andrei V. Zaitsev, Oksana A. Arefeva, Natalia A. Sazonona, Vladimir D. Melnikov, Yuriy A. Kim, Arseniy A. Shiryaev, Alexander O. Vasilyev, Igor O. Gritskov, Alexander V. Govorov, and Dmitry Yu. Pushkar
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bacteriophages ,antibiotic resistance ,lower urinary tract infections ,recurrent cystitis ,phage therapy ,Gynecology and obstetrics ,RG1-991 - Abstract
Background. Urinary tract infections remain one of the urgent problems in the aspect of qualified medical care. The causative agents of nosocomial infections are becoming more and more resistant to the drugs used, while the rate of new drugs synthesis is lower than the rate of development of antibiotic resistance. Routine and empirical prevention of recurrent urinary tract infections is often ineffective. Aim. To study the efficacy and safety of intravesical application of the drug based on bacteriophages in therapy in patients with chronic recurrent cystitis. Materials and methods. A clinical study was carried out to study the efficacy and safety of the drug for intravesical administration based on bacteriophages in therapy in patients with chronic recurrent cystitis. The study included 75 patients who were divided into 3 groups in a 1: 1: 1 ratio. In the main group, the drug for intravesical administration based on bacteriophages, as well as rectal suppositories with bacteriophages were used; in the control group only a drug for intravesical administration based on bacteriophages or rectal suppositories with bacteriophages. On visits 1-4, all patients underwent a clinical blood test, general urine analysis, bacteriological urine analysis, as well as urine analysis by the polymerase chain reaction method. The analysis of the patients condition in groups was carried out according to the dynamics of main clinical symptoms changes, data from validated scales for assessing pelvic pain and urgency/frequency of urination and assessment of symptoms of acute cystitis (Acute Cystitis Symptom Score ACSS), as well as the dynamics of changes in objective parameters of laboratory studies and possible changes in sensitivity uropathogens to antibacterial drugs. Results. The average age of the patients included in the study was 50.6 years. In all 3 groups, bacteriological examination of urine showed a predominant growth of Escherichia coli (3104 CFU/ml). In the course of the study, there was a good tolerance to therapy, a decrease in clinical symptoms, as well as a significant decrease in the total score according to the pelvic pain scale and urgency/frequency of urination and the ACSS scale in all patients. Conclusion. The emergence of a large number of microorganisms resistant to various antibiotics and their rapid spread in the environment has led to an increase in scientific interest in bacteriophage therapy as an alternative method of treatment. The overall subjective effectiveness of the therapy in our study was more than 80%, safety - 100%. Further research will allow for a personalized approach to the treatment of infectious diseases of the urinary system.
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- 2021
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4. The experience of using a bacteriophages-based complex antibacterial and analgesic drug in gel formulation in women who underwent various instrumental and diagnostic and treatment interventions
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Alexander O. Vasilyev, Natalia A. Sazonova, Vladimir D. Melnikov, Amir F. Gabdullin, Andrei V. Zaitsev, Arseniy A. Shiryaev, Yuriy A. Kim, Elena A. Prilepskaya, and Dmitry Yu. Pushkar
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bacteriophages ,antibiotic resistance ,urinary tract infections ,bacteriophage therapy ,Gynecology and obstetrics ,RG1-991 - Abstract
During the spread of bacterial infections with extensive drug resistance, the potential of existing antibacterial drugs is significantly reduced. The medical community is seeking opportunities for the rational use of antibacterial drugs, the development of new drugs, as well as the use of alternative treatments for these infections. Aim. The objective of this study was to evaluate the effectiveness of the use of a complex antibacterial and analgesic drug based on bacteriophages in gel form during various instrumental studies and diagnostic procedures in order to minimize the risk of the urinary system infections complications. Materials and methods. The study included 235 women aged 18 to 75 years who underwent treatment at the Moscow State Clinical Hospital named after Spasokukotsky and in the clinic of urology of Moscow State University of Medicine and Dentistry from September 2019 to January 2020. During the manipulation, all patients of the main group (n=120) used a developed preparation based on bacteriophages, and in the control group (n=115), a topical gel based on chlorhexidine dihydrochloride and lidocaine hydrochloride was used. All patients before the manipulation, as well as 10 days after the manipulation, underwent bacteriological analysis of urine. Efficiency assessment was carried out on the basis of laboratory data obtained, as well as according to the visual analogue scale of the pain syndrome severity. Results. None of the patients in the main group showed intolerance, side effects and allergic reactions of the developed drug based on bacteriophages. Bacteriological analysis of urine received before manipulation in both groups showed the absence of clinically significant titers of pathogenic bacteria, while 1 week after manipulation the number of titers of pathogenic bacteria (104) was significantly higher in the control group (p0.04). In patients of the main group, the incidence of dysuria was lower compared with the control group (p0.05). Conclusion. The study showed good tolerance of the developed drug and its clinical effectiveness in reducing the number of symptomatic bacteriuria; severity of pain after undergoing manipulation was relatively lower in the main group of patients. Conducting multicenter studies with the inclusion of a larger number of patients in the future will reduce the economic costs associated with treating patients by reducing the number of cases of nosocomial infections and reducing postoperative time spent by patients in the hospital.
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- 2020
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5. Fluorinated maleimide-substituted porphyrins and chlorins: synthesis and characterization
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Valentina A. Ol’shevskaya, Elena G. Kononova, and Andrei V. Zaitsev
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chlorin ,maleimide ,porphyrin ,spectral characteristics ,synthesis ,Science ,Organic chemistry ,QD241-441 - Abstract
Maleimide-containing fluorinated porphyrins and chlorins were prepared based on the reaction of Zn(II) or Ni(II) complexes of 5,10,15,20-tetrakis(4-amino-2,3,5,6-tetrafluorophenyl)porphyrin and chlorin with maleic anhydride. Porphyrin maleimide derivatives were also prepared by the reaction of 5,10,15,20-tetrakis(4-azido-2,3,5,6-tetrafluorophenyl)porphyrinato Zn(II) or Ni(II) with N-propargylmaleimide via the CuAAC click reaction to afford fluorinated porphyrin–triazole–maleimide conjugates. New maleimide derivatives were isolated in reasonable yields and identified by UV–vis, 1H NMR, 19F NMR spectroscopy and mass-spectrometry.
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- 2019
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6. A New Bound in the Littlewood–Offord Problem
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Friedrich Götze and Andrei Yu. Zaitsev
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concentration functions ,inequalities ,the Littlewood–Offord problem ,sums of independent random variables ,Mathematics ,QA1-939 - Abstract
The paper deals with studying a connection of the Littlewood–Offord problem with estimating the concentration functions of some symmetric infinitely divisible distributions. It is shown that the concentration function of a weighted sum of independent identically distributed random variables is estimated in terms of the concentration function of a symmetric infinitely divisible distribution whose spectral measure is concentrated on the set of plus-minus weights.
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- 2022
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7. Resolution of the Expert Council on the use of the anti-inflammatory drug ammonium glycyrrhizinate in the treatment of acute respiratory infections and allergic diseases of the respiratory tract
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Natalia A. Geppe, Aleksandr B. Malakhov, Evgeniia V. Boitsova, Inessa N. Gaimolenko, Irina N. Ermakova, Andrei A. Zaitsev, Evgenii F. Ivakhnenko, Natalia A. Il'enkova, Andrei V. Kamaev, Iuliia B. Kliukhina, Elena G. Kondiurina, Olga M. Konova, Vera V. Kulagina, Natalia S. Lev, Elena I. Liutina, Manuel M. Megirian, Irina M. Mel'nikova, Vitalii V. Meshcheriakov, Iurii L. Mizernitskii, Alena K. Mironova, Evgenii V. Mikhalev, Lidiia I. Mozzhukhina, Nuriniso D. Odinaeva, Elena B. Pavlinova, Nadezhda S. Pobedinskaia, Margarita A. Skachkova, Natalia D. Soroka, Svetlana V. Trishina, Sofia A. Tsar'kova, and Irina P. Shuliak
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In June 2022, within the XI International Educational Consensus on Respiratory Medicine in Pediatrics, an expert council on the anti-inflammatory agent ammonium glycyrrhizinate in treating acute respiratory infections and allergic diseases of the respiratory tract was held in Vladimir. The resolution of the Expert Council is presented. Based on these studies, experts recommend the use of ammonium glycyrrhizinate in patients with acute respiratory tract infection (including COVID-19); in the rehabilitation period of patients who recovered from the new coronavirus infection with lung involvement; patients with recurrent obstructive bronchitis, including those at high risk of bronchial asthma; patients with allergic rhinitis; patients with mild to moderate asthma.
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- 2023
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8. BODIPY derivatives modified with carborane clusters: synthesis, characterization and DFT studies
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Andrei V. Zaitsev, Sergey S. Kiselev, Alexander F. Smol'yakov, Yury V. Fedorov, Elena G. Kononova, Yurii A. Borisov, and Valentina A. Ol'shevskaya
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Organic Chemistry ,Physical and Theoretical Chemistry ,Biochemistry - Abstract
Synthesis and characterization of carborane BODIPYs were described. UV and fluorescence spectra were studied. DFT calculations were performed to study the geometrical structures and chemical reactivity descriptors of synthesized compounds.
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- 2023
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9. Maleimide-functionalized BODIPY dyes: Synthesis, structural determination and conjugation with carborane thiols
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Valentina Antonovna Ol'shevskaya, Andrei V. Zaitsev, Anna S. Morozyuk, Elena G. Kononova, and Alexander F. Smol’yakov
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General Chemistry - Abstract
A series of new BODIPY conjugates containing maleimide or carborane-succinimide-triazole functional groups were prepared from synthetically available azido-substituted BODIPYs. The structure of new synthesized compounds was characterized by UV-vis, IR, NMR and mass spectrometry. The crystal structures of BODIPY-maleimide conjugates were determined by single crystal X-ray diffraction study. The carborane-containing BODIPYs can be promising agents for photodynamic and boron neutron capture therapy.
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- 2022
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10. Emission of volatile organic compounds by plants on the floor of boreal and mid-latitude forests
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Valery A. Isidorov, Ewa Pirożnikow, Viktoria L. Spirina, Alexander N. Vasyanin, Svetlana A. Kulakova, Irina F. Abdulmanova, and Andrei A. Zaitsev
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Atmospheric Science ,Environmental Chemistry - Abstract
The forests of the boreal and mid-latitude zones of the Northern Hemisphere are the largest source of reactive volatile organic compounds (VOCs), which have an important impact on the processes occurring in the atmospheric boundary layer. However, the composition of biogenic emissions from them remains incompletely characterized, as evidenced by the significant excess OH radical concentrations predicted by models in comparison with those observed under the forest canopy. The missing OH sink in the models may be related to the fact that they do not take into account the emission of highly reactive VOCs by vegetation on the forest floor. In this work, we report the results of laboratory determinations of the composition of VOCs emitted by representatives of different groups of plants that form the living soil cover (LSC) in the forests of the boreal and mid-latitude zones: bryophytes, small shrubs, herbaceous plants, and ferns. In the chromatograms of volatile emissions of all 11 studied plant species, 254 compounds with carbon atoms ranging in number from two to 20 were registered. All plants were characterized by the emission of terpenes, accounting for 112 compounds, and the second largest group (35 substances) was formed by carbonyl compounds. Both groups of compounds are characterized by high reactivity and are easily included in the processes of gas-phase oxidation with the participation of radicals HO, NO3 and ozone. These data indicate the importance of a thorough study of the so far disregarded source of VOCs, that is, the LSC in forests.
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- 2022
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11. Об альтернативных аппроксимирующих распределениях в многомерном варианте второй равномерной предельной теоремы Колмогорова
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Friedrich Gotze, Фридрих Гeтце, and Andrei Yurevich Zaitsev
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Цель работы - показать, что недавние результаты авторов об аппроксимации распределений сумм независимых слагаемых безгранично делимыми законами на выпуклых многогранниках могут быть получены с помощью некоторого альтернативного класса аппроксимирующих безгранично делимых распределений. Мы также обобщим результаты на бесконечномерный случай.
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- 2022
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12. Applying the aggregated indices randomization method to prioritize cluster development
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Andrei A. Zaitsev, Dmitrii V. Kolodko, and Tamara N. Selent'eva
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Cluster development ,Computer science ,0502 economics and business ,05 social sciences ,General Medicine ,Data mining ,050207 economics ,010501 environmental sciences ,computer.software_genre ,01 natural sciences ,computer ,0105 earth and related environmental sciences - Abstract
Subject. This article discusses the innovation activities of companies participating in clusters. Objectives. The article aims to justify a choice of State support facilities for the innovation activities of enterprises participating in clusters. Methods. For the study, we used the hierarchical aggregated indices randomization method and Monte Carlo method. Results. During the study of cluster construction in St. Petersburg, an array of data was obtained. Based on calculations, we show the choice of two enterprises, the best ones in terms of assessing the probability of dominance. We justify the possibility of using such a characteristic of randomized aggregated indices as the value of mathematical expectation, as a choice criterion. Conclusions. The algorithm developed to apply the aggregated indices randomization method develops an institutional approach to the analysis of regional clusters.
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- 2021
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13. Accounting policy as a constituent of internal control and corporate economic security
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Yuliya N. Stetsyunich and Andrei A. Zaitsev
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0404 agricultural biotechnology ,business.industry ,Applied Mathematics ,General Mathematics ,Control (management) ,Economic security ,0402 animal and dairy science ,Accounting ,04 agricultural and veterinary sciences ,Business ,Accounting policy ,040401 food science ,040201 dairy & animal science - Abstract
Subject. The article discusses the consistency of accounting policies, internal control and constituents of corporate economic security. Objectives. The study determines the process of articulating the term Accounting Policy at the legislative and normative levels nationwide and worldwide. We compare our own interpretations of corporate economic security. The article traces the impact of the accounting policy on areas of internal control and corporate economic securities. Methods. The study is based on general methods of research, such as the dialectical method, methods of analysis and synthesis, induction and deduction, and semantic analysis. Results. The article shows the impact of internal and external factors, which also influence corporate economic security and translate into the formation of corporate accounting policies. Conclusions and Relevance. Economic security is an aspect that every entity pursues. Therefore, it is important to thoroughly study how clauses of accounting policies influence the aspect from perspectives of business entities. The impact of constituents of corporate accounting policies, as evaluated herein, allow to consider adverse factors and help prevent negative consequences that internal and external factors may cause to corporate economic security. The findings contribute to accounting techniques for financial management in order to ensure the economic security. They are of practical significance for business leaders and financial personnel.
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- 2021
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14. Vibrational Spectra of 5,10,15,20-Tetraphenylporphyrin (H2TPP) and Platinum(II) 5,10,15,20-Tetra(phenyl/pentafluorophenyl)porphyrins (PtTPP and PtTF5PP)
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Ivan Yu. Kurochkin, Valentina A. Olshevskaya, Andrei V. Zaitsev, Nina I. Girichevac, and Georgy V. Girichev
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Organic Chemistry ,Analytical Chemistry - Published
- 2021
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15. Design features of the tropical unicar for urban passenger transport
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Viktar A. Harakh, Andrei D. Zaitsev, Michael I. Tsyrlin, Anatoli E. Unitsky, and Unitsky String Technologies Co.
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Passenger transport ,Transport engineering - Abstract
The paper examines the design features of the tropical unicar for urban passenger transport. The description of the unicar main components is given, its advantages over the basic model are presented.
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- 2021
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16. Algorithms for the management of patients with a new coronavirus COVID-19 infection in a hospital. Guidelines
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Andrei A. Zaitsev, Vladimir A. Chernetsov, Sergei A. Chernov, Oleg I. Kudriashov, Mikhail B. Patsenko, Valerii V. Stets, and Evgenii V. Kriukov
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medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,business.industry ,medicine ,Intensive care medicine ,medicine.disease_cause ,business ,Coronavirus - Abstract
The guide is devoted to issues of practice on diagnosis and treatment of the new coronavirus COVID-19 infection. The purpose of creating this document was the need to develop a unified approach to providing care to patients with the new coronavirus COVID-19 infection in military hospitals in terms of the practical experience of hospital specialists, the requirements of national guidelines. The most important recommen-dations concern the issues of correct understanding of the disease, algorithms for actions of medical personnel and pharmacotherapy regimens for patients with coronavirus infection.
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- 2020
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17. Assessment of the duration of QT interval in patients with COVID-19 during treatment with hydroxychloroquine and azithromycin
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Andrei A. Zaitsev, Filipp A. Orlov, Tatiana N. Pantiukhova, and Gleb E. Kubenskii
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medicine.medical_specialty ,Coronavirus disease 2019 (COVID-19) ,Duration (music) ,business.industry ,Internal medicine ,medicine ,Cardiology ,Hydroxychloroquine ,In patient ,Azithromycin ,business ,QT interval ,medicine.drug - Abstract
At the end of 2019, an outbreak of a novel coronavirus infection occurred in PRC, the causative agent of which was given the temporary name 2019-nCoV. COVID-19 is a complex multisystem disease which causes harmful effects not only on the lungs, but also on the cardiac conduction system. Aim. To assess the duration of corrected QT interval in patients with COVID-19 during treatment with hydroxychloroquine and azithromycin, and to identify the relationship between this indicator and the severity of interstitial pneumonitis. Materials and methods. We studied medical records of 40 men and 4 women, who were treated in the infectious diseases department of Acad. N.N. Burdenko Main Military Clinical Hospital from March 20 to May 20, 2020. All patients underwent resting digital 12-lead electrocardiography: at the time of admission to the hospital and after 6 days of therapy using the "Myocard-12" system. In our study, 30 patients were treated with azithromycin at a total daily dose of 500 mg for 5 to 10 days; 21 patients – with hydroxychloroquine at a dose of 400 mg 2 times a day on the 1st day of treatment and 200 mg 2 times a day for the next 5 days; and 7 patients received azithromycin and hydroxychroloquine combination. Results. To assess the duration of corrected QT interval depending on the severity of patient's status and the degree of lung damage, we compared the mean QT interval depending on the degree of lung damage on computed tomography. There was no significant difference in this indicator in patients with pneumonia of varying severity. However, when using the combination of azithromycin and hydroxychloroquine after 6 days, there was a significant increase in the mean cor-rected QT interval compared to its baseline value (before treatment). Conclusion. Patients hospitalized with COVID-19 have an initially prolonged corrected QT interval. The combined use of azithromycin and hydroxychloroquine in a short time causes a significant increase in the corrected QT interval in patients with COVID-19.
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- 2020
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18. Cough: from basics to pharmacotherapy
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Sergei V. Okovityi and Andrei A. Zaitsev
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medicine.medical_specialty ,Pharmacotherapy ,business.industry ,Medicine ,business ,Intensive care medicine ,respiratory tract diseases - Abstract
The article considers current issues in the management of patients with cough. It provides a definition of cough, its clinical classification, analysis of main causes, a list of necessary diagnostic methods and directions of pharmacotherapy. A place is given for the differential diagnosis of various pathological conditions and diseases, the leading clinical sign of which is cough. The authors describe the characteristics of drugs for the treatment of cough, the principles of using mucoactive drugs, practical recommendations for rational pharmacotherapy of unproductive and productive cough.
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- 2020
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19. Methodological Approach to Substantiation of Capital Investments of Gold Fields Based on Unit Costs
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Andrei Yu. ZAITSEV
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Marginal cost ,lcsh:TN1-997 ,assessment ,field value ,Geology ,Geotechnical Engineering and Engineering Geology ,Unit (housing) ,Capital expenditure ,Balance (accounting) ,Capital (economics) ,investments ,Value (economics) ,Econometrics ,Economics ,Capital cost ,Fixed asset ,Economic Geology ,capital expenditures ,lcsh:Mining engineering. Metallurgy ,PLC Polymetal - Abstract
Issues of assessing capital expenditures for setting mineral deposits into operation are considered. Existing methods have a number of advantages and disadvantages, but they are determined separately for each type of fixed assets of the field. A simple method, that allows to quickly and easily determine the amount of capital costs for setting gold deposit into operation, based on data on ore reserves, as well as unit costs, taking into account the degree of infrastructure development at the deposit, is proposed. Presented methodology allows one to determine the real amount of initial capital expenditures of a gold deposit, calculate their marginal (recommended) value, and also assess the balance of capital investments in the development of a particular deposit, taking into account the existing one in the company's investment portfolio. The methodology is based on analysis of empirical material, which used real capital costs for development of gold deposits (and foreign-metal impurities) by Polymetal International plc. As a result of a statistical study, method for determining the marginal cost of a field is obtained.
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- 2019
20. A straightforward approach to carborane-substituted BODIPY derivatives via nucleophilic aromatic substitution: Synthesis and photodynamic properties
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Andrei V. Zaitsev, Elena G. Kononova, Alina A. Markova, Anna V. Shibaeva, Alexey A. Kostyukov, Anton E. Egorov, Vladimir A. Kuzmin, Alexander A. Shtil, and Valentina A. Ol'shevskaya
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Process Chemistry and Technology ,General Chemical Engineering - Published
- 2022
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21. An improved multivariate version of Kolmogorov's second uniform limit theorem
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Friedrich Götze, Andrei Yu. Zaitsev, and Dmitry Zaporozhets
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Statistics and Probability ,Pure mathematics ,Multivariate statistics ,Work (thermodynamics) ,Applied Mathematics ,General Mathematics ,Closeness ,Probability (math.PR) ,Regular polygon ,Uniform limit theorem ,Polyhedron ,FOS: Mathematics ,Mathematics - Probability ,Mathematics ,60F05, 60E15, 60G50 - Abstract
The aim of the present work is to show that the results obtained earlier on the approximation of distributions of sums of independent summands by infinitely divisible laws may be transferred to the estimation of the closeness of distributions on convex polyhedra., 12 pages
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- 2019
22. INVESTIGATION OF NUCLEAR EMULSIONS IN TERMS OF NEUTRON DOSIMETRY
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I. Ambrožová, Andrei A Zaitsev, Václav Štěpán, Antonín Kolros, Michal Košťál, O. Ploc, Martina Lužová, Věra Bradnová, Martin Kákona, and P. I. Zarubin
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Bromides ,food.ingredient ,Materials science ,chemistry.chemical_element ,Lithium ,01 natural sciences ,Gelatin ,Helium ,030218 nuclear medicine & medical imaging ,Fast Neutrons ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,food ,0103 physical sciences ,Image Processing, Computer-Assisted ,Dosimetry ,Neutron detection ,Radiology, Nuclear Medicine and imaging ,Neutron ,Boron ,Radiometry ,Neutrons ,Radiation ,Radiological and Ultrasound Technology ,Silver halide ,010308 nuclear & particles physics ,Phantoms, Imaging ,Radiochemistry ,Public Health, Environmental and Occupational Health ,Silver Compounds ,General Medicine ,Neutron temperature ,chemistry ,Emulsion ,Calibration ,Emulsions ,Hydrogen - Abstract
Neutron detection using nuclear emulsions can offer an alternative in personal dosimetry. The production of emulsions and their quality have to be well controlled with respect to their application in dosimetry. Nuclear emulsions consist mainly of gelatin and silver halide. Gelatin contains a significant amount of hydrogen, which can be used for fast neutron detection. The addition of B-10 in the emulsion is convenient for thermal neutron detection. In this paper, standard nuclear emulsions BR-2 and nuclear emulsions BR-2 enriched with boron produced at the Slavich Company, Russia, were applied for evaluation of fast and thermal neutron fluences. The results were obtained by calculation from the presumed emulsion composition without prior calibration. Evidence that nuclear emulsions used in the experiment are suitable for neutron dosimetry is provided.
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- 2019
23. Неравенства Арака для функций концентрации и проблема Литтлвуда - Оффорда
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Yu. S. Eliseeva, Friedrich Götze, Andrei Yur'evich Zaitsev, and Фридрих Гeтце
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Combinatorics ,010104 statistics & probability ,010102 general mathematics ,Littlewood–Offord problem ,0101 mathematics ,01 natural sciences ,Mathematics - Published
- 2017
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24. To the history of Saint-Petersburg school of Probability and Statistics. I. Limit theorems for sums of independent random variables
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Mikhail Lifshits, Yakov Nikitin, Andrei Yu. Zaitsev, V. V. Petrov, and Abram A. Zinger
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Discrete mathematics ,General Mathematics ,010102 general mathematics ,General Physics and Astronomy ,Law of the iterated logarithm ,Probability and statistics ,Empirical measure ,01 natural sciences ,010104 statistics & probability ,Convergence of random variables ,Law of large numbers ,Limit (mathematics) ,0101 mathematics ,Random variable ,Central limit theorem ,Mathematics - Abstract
This is the first in a series of reviews devoted to the scientific achievements of the Leningrad–St. Petersburg school of probability and statistics in the period from 1947 to 2017. It is devoted to limit theorems for sums of independent random variables—a traditional subject for St. Petersburg. It refers to the classical limit theorems: the law of large numbers, the central limit theorem, and the law of the iterated logarithm, as well as important relevant problems formulated in the second half of the twentieth century. The latter include the approximation of the distributions of sums of independent variables by infinitely divisible distributions, estimation of the accuracy of strong Gaussian approximation of such sums, and the limit theorems on the weak almost sure convergence of empirical measures generated by sequences of sums of independent random variables and vectors.
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- 2018
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25. Ionizing radiation effects on soil biota: Application of lessons learned from Chernobyl accident for radioecological monitoring
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Konstantin B. Gongalsky, Nobuhiro Kaneko, Taizo Nakamori, and Andrei S. Zaitsev
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medicine.medical_specialty ,Soil biology ,Soil Science ,Radioactive waste ,Ionizing radiation ,law.invention ,High resistance ,Radioecology ,law ,Environmental protection ,Nuclear power plant ,medicine ,Environmental science ,Ecology, Evolution, Behavior and Systematics - Abstract
Russia, Ukraine, Belarus, Kazakhstan and some other neighboring countries bear the heritage of several Soviet era nuclear disasters and the resulting severe radioactive pollution of vast territories. The most famous of them is the Chernobyl catastrophe on April 26, 1986 which resulted in a massive radioisotope fallout (0.185 MBq m −2 or higher) over about 25,000 km 2 of the territory of the former USSR alone. Extensive radioecological research around Chernobyl demonstrated that despite high resistance of most of soil-dwelling organisms to ionizing radiation, some soil animals were very vulnerable to radioactive pollution due to low motility, direct contact with hot particles and radioisotope accumulation in soil. These are the reasons that soil organisms are very important organisms for long-term radioecological observations. In this review, we analyze published data on the response of different soil taxa to radioisotope contamination of soil near Chernobyl and other nuclear accident locations. Field results are compared with the available experimental data. Earthworms, millipedes, collembolans and oribatid mites were recognized as the most appropriate biomonitors of different radioactivity levels and types of radioactive pollution. Synthesis of this knowledge allowed us to propose a multilevel system of soil radioecological monitoring, which may be useful for studying the short- and long-term environmental consequences of the recent catastrophe at Fukushima-1 nuclear power plant in Japan, as well as other locations vulnerable to radioactive pollution.
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- 2014
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26. Точность сильной гауссовской аппроксимации для сумм независимых случайных векторов
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Andrei Yur'evich Zaitsev
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Mathematical analysis ,Applied mathematics ,Gaussian approximation ,Mathematics - Published
- 2013
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27. How do soil fauna and soil microbiota respond to beech forest growth?
- Author
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Volkmar Wolters, Andrei S. Zaitsev, Matthieu Chauvat, and Ernst Gabriel
- Subjects
Biomass (ecology) ,biology ,Soil biodiversity ,Ecology ,Soil biology ,Soil organic matter ,Environmental science ,Animal Science and Zoology ,Soil classification ,Ecological succession ,Monoculture ,biology.organism_classification ,Beech - Abstract
The dynamics and performance of soil biota during forest rotation were studied in monoculture beech stands forming a chronosequence of four different age-classes (30, 62, 111, 153 yr). Biomass was monitored in major groups of microflora, microfauna, mesofauna, and macrofauna. Resource availability (litter layer, soil organic mater), biomass of the two dominant decomposer groups (microflora, earthworms) as well as the biomass of mesofauna and microfauna were found to remain quite stable during forest succession. Nevertheless, the marked increase of the biomasses of primary decomposers (fungi, saprophagous macroinvertebrates) in the 62-year-old stand, followed by an increase of the biomasses of macropredators in the 111-year-old stand, indicate substantial changes of several components of edaphic communities during forest development. However, constant values of soil respiration suggest that the overall performance of the soil food web does not change during beech forest succession. Thus, the decomposer system of lowland managed beech forests on calcareous soils seems to be very stable over time. We suggest that earthworm activity might have masked impacts of forest development on other soil biota and led to an astounding stability of decomposer assemblages during beech forest rotation.
- Published
- 2009
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28. How do soil fauna and soil microbiota respond to beech forest growth?
- Author
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Matthieu CHAUVAT, Andrei S. ZAITSEV, Ernst GABRIEL, Volkmar WOLTERS
- Subjects
Beech ,forest ,lcsh:Zoology ,soil food-web ,lcsh:QL1-991 ,ecosystem performance ,chronosequence - Abstract
The dynamics and performance of soil biota during forest rotation were studied in monoculture beech stands forming a chronosequence of four different age-classes (30, 62, 111, 153 yr). Biomass was monitored in major groups of microflora, microfauna, mesofauna, and macrofauna. Resource availability (litter layer, soil organic mater), biomass of the two dominant decomposer groups (microflora, earthworms) as well as the biomass of mesofauna and microfauna were found to remain quite stable during forest succession. Nevertheless, the marked increase of the biomasses of primary decomposers (fungi, saprophagous macroinvertebrates) in the 62-year-old stand, followed by an increase of the biomasses of macropredators in the 111-year-old stand, indicate substantial changes of several components of edaphic communities during forest development. However, constant values of soil respiration suggest that the overall performance of the soil food web does not change during beech forest succession. Thus, the decomposer system of lowland managed beech forests on calcareous soils seems to be very stable over time. We suggest that earthworm activity might have masked impacts of forest development on other soil biota and led to an astounding stability of decomposer assemblages during beech forest rotation [Current Zoology 55 (4): 272–278, 2009].
- Published
- 2009
29. Bounds for the Rate of Strong Approximation in the Multidimensional Invariance Principle
- Author
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Friedrich Götze and Andrei Yur'evich Zaitsev
- Subjects
Invariance principle ,Mathematical analysis ,Applied mathematics ,Mathematics - Published
- 2008
- Full Text
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30. New applications of Arak's inequalities to the Littlewood-Offord problem
- Author
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Friedrich Götze and Andrei Yu. Zaitsev
- Subjects
Independent identically distributed ,60G50 ,Inequality ,Littlewood-Offord problem ,General Mathematics ,media_common.quotation_subject ,Littlewood–Offord problem ,of independent random variables ,Structure (category theory) ,Inverse ,Sums ,Context (language use) ,Algebraic geometry ,01 natural sciences ,0103 physical sciences ,FOS: Mathematics ,0101 mathematics ,media_common ,Mathematics ,010102 general mathematics ,Concentration functions ,Probability (math.PR) ,Algebra ,010307 mathematical physics ,Inequalities ,Random variable ,Mathematics - Probability - Abstract
Let $X,X_1,\ldots,X_n$ be independent identically distributed random variables. In this paper we study the behavior of concentration functions of weighted sums $\sum_{k=1}^{n}X_ka_k $ with respect to the arithmetic structure of coefficients $a_k$ in the context of the Littlewood--Offord problem. In recent papers of Eliseeva, G\"otze and Zaitsev, we discussed the relations between the inverse principles stated by Nguyen, Tao and Vu and similar principles formulated by Arak in his papers from the 1980's. In this paper, we will derive some more general and more precise consequences of Arak's inequalities providing new results in the context of the Littlewood-Offord problem., Comment: 23 pages. arXiv admin note: text overlap with arXiv:1506.09034
- Published
- 2016
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31. Arak's inequalities for concentration functions and the Littlewood-Offord problem
- Author
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Yulia S. Eliseeva, Friedrich Götze, and Andrei Yu. Zaitsev
- Subjects
Inequality ,General Mathematics ,media_common.quotation_subject ,010102 general mathematics ,Littlewood–Offord problem ,Structure (category theory) ,Inverse ,01 natural sciences ,010104 statistics & probability ,Applied mathematics ,0101 mathematics ,Random variable ,Mathematics ,media_common - Abstract
In this paper we study the behavior of concentration functions of weighted sums of independent random variables with respect to the arithmetic structure of coefficients. Recently, Tao and Vu formulated a so-called Inverse Principle in the Littlewood–Offord problem. We discuss the relations between this Inverse Principle and a similar principle formulated for sums of arbitrarily distributed independent random variables formulated by T. Arak in the 1980’s.
- Published
- 2016
- Full Text
- View/download PDF
32. Long-term succession of oribatid mites after conversion of croplands to grasslands
- Author
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Jens Dauber, Andrei S. Zaitsev, Rainer Waldhardt, and Volkmar Wolters
- Subjects
Temperate grassland ,geography ,geography.geographical_feature_category ,Ecology ,Chronosequence ,Soil Science ,Ecological succession ,Biology ,biology.organism_classification ,Agricultural and Biological Sciences (miscellaneous) ,Grassland ,Dominance (ecology) ,Species richness ,Arable land ,Oribatida - Abstract
The paper deals with the long-term development (55 years) of oribatid communities (Acari) during grassland succession following the conversion of arable fields. The study was carried out on a chronosequence of temperate grassland sites in the Lahn-Dill-Bergland (Central Hesse, Germany). The “space-for-time” substitution method was applied. Increasing abundance at early stages of the conversion process (until the age of 13–28 years) points to release from the stress exerted by arable management. Saturation of abundance and richness indicates strong limiting forces acting upon the oribatid community at intermediate and late stages of succession. The continuous increase in the dominance of surface-dwelling and non-specialized species suggests a considerable change in the nature of these limiting forces during the successional process. General Regression Model (GRM) analysis revealed an increasing impact of external factors on the oribatid community during grassland succession, and a shift in the major driving forces determining oribatid abundance from soil conditions to vegetation conditions and then to a combined effect of both soil and vegetation conditions.
- Published
- 2006
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- View/download PDF
33. RELATIONSHIP AMONG THE SPECIES RICHNESS OF DIFFERENT TAXA
- Author
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Volkmar Wolters, Andrei S. Zaitsev, and Janne Bengtsson
- Subjects
Ecology ,Biome ,Fungi ,Biodiversity ,Species diversity ,Body size and species richness ,Plants ,Biology ,Taxon ,Meta-Analysis as Topic ,Spatial ecology ,Animals ,Species richness ,Ecology, Evolution, Behavior and Systematics ,Trophic level - Abstract
Spatially explicit forecasting of changes in species richness is key to designing informative scenarios on the development of diversity on our planet. It might be possible to predict changes in the richness of inadequately investigated groups from that of groups for which enough information is available. Here we evaluate the reliability of this approach by reviewing 237 richness correlations extracted from the recent literature. Of the 43 taxa covered, beetles, vascular plants, butterflies, birds, ants, and mammals (in that order) were the most common ones examined. Forests and grasslands strongly dominated the ecosystem types studied. The variance explanation (R 2 ) could be calculated for 152 cases, but only 53 of these were significant. An average correlation effect size of 0.374 (95% CI ¼ 60.0678) indicates positive but weak correlations between taxa within the very heterogeneous data set. None of the examined explanatory variables (spatial scale, taxonomic distance, trophic position, biome) could account for this heterogeneity. However, studies focusing on 10-km 2 grid cells had the highest variance explanation. Moreover, within-phylum between- class comparisons had marginally significantly lower correlations than between-phylum comparisons. And finally, the explanatory power of studies conducted in the tropics was significantly higher than that of studies conducted in temperate regions. It is concluded that the potential of a correlative approach to species richness is strongly diminished by the overall low level of variance explanation. So far, no taxon has proved to be a universal or even particularly good predictor for the richness of other taxa. Some suggestions for future research are inclusion of several taxa in models aiming at regional richness predictions, improvement of knowledge on species correlations in human dominated systems, and a better understanding of mechanisms underlying richness correlations.
- Published
- 2006
- Full Text
- View/download PDF
34. Estimation de la vitesse d'approximation dans un lemme de déPoissonisation
- Author
-
Andrei Yu. Zaitsev
- Subjects
Statistics and Probability ,Lemma (mathematics) ,Rate of approximation ,Mathematical analysis ,Applied mathematics ,Céa's lemma ,Statistics, Probability and Uncertainty ,Mathematics ,Exponential function - Abstract
Estimates of the rate of approximation in a de-Poissonization lemma of Beirlant and Mason [1] is obtained for the case where the distribution satisfy a quantitative condition of existence of exponential moments introduced in [6].
- Published
- 2002
- Full Text
- View/download PDF
35. Shifts in soil testate amoeba communities associated with forest diversification
- Author
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Anatoliy A. Bobrov, Andrei S. Zaitsev, and Volkmar Wolters
- Subjects
Ecology ,biology ,Soil biology ,Soil Science ,Soil classification ,Forestry ,Forests ,biology.organism_classification ,Biota ,Amoebozoa ,Trees ,Soil ,Germany ,Fagus ,Species richness ,Monoculture ,Picea ,Cercozoa ,Relative species abundance ,Beech ,Abies ,Ecology, Evolution, Behavior and Systematics ,Undergrowth ,Global biodiversity - Abstract
We studied changes of testate amoeba communities associated with the conversion of spruce monocultures into mixed beech-fir-spruce forests in the Southern Black Forest Mountains (Germany). In this region, forest conversion is characterized by a gradual development of beech undergrowth within thinned spruce tree stands leading to multiple age continuous cover forests with a diversified litter layer. Strong shifts in the abundance of testate amoeba observed in intermediate stages levelled off to monoculture conditions again after the final stage of the conversion process had been reached. The average number of species per conversion stage (i.e., local richness) did not respond strongly to forest conversion, but the total number of species (i.e., regional richness) was considerably higher in the initial stage than in the mixed forests, due to the large number of hygrophilous species inhabiting spruce monocultures. Functional diversity of the testate amoeba community, however, significantly increased during the conversion process. This shift was closely associated with improved C and N availability as well as higher niche diversity in the continuous cover stands. Lower soil acidity in these forests coincided with a higher relative abundance of eurytopic species. Our results suggest that testate amoeba communities are much more affected by physicochemical properties of the soil than directly by litter diversity.
- Published
- 2014
36. Multidimensional Version of a Result of Sakhanenko in the Invariance Principle for Vectors with Finite Exponential Moments. III
- Author
-
Andrei Yur'evich Zaitsev
- Subjects
Invariance principle ,Applied mathematics ,Exponential function ,Mathematics - Published
- 2001
- Full Text
- View/download PDF
37. Species diversity and metal accumulation in oribatid mites (Acari, Oribatida) of forest affected by a metallurgical plant
- Author
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Nico M. van Straalen, Andrei S. Zaitsev, and Animal Ecology
- Subjects
Cadmium ,biology ,Metallurgy ,Community structure ,Soil Science ,chemistry.chemical_element ,Species diversity ,Zinc ,biology.organism_classification ,chemistry ,Agronomy ,Soil water ,Mite ,Acari ,Oribatida ,Ecology, Evolution, Behavior and Systematics - Abstract
Summary A study was made of oribatid mite communities and their responses to metal contamination derived from the Kosogorsky metallurgical plant located in the Tula District, Russia. Mite communities were sampled in three different seasons in four sites at different distances from the smelter. Concentrations of zinc, copper, cadmium, lead and iron were measured in ten mite species. The data show that the mite community as a whole is quite tolerant to the metal contamination caused by the Kosogorsky plant. At the polluted sites some species typical for nutrient-rich soils appeared, but community structure and species diversity were not seriously affected by metal contamination. In general, oribatid mites accumulated metals to very high internal concentrations. Average Cu, Cd, Pb and Fe concentrations did not differ significantly between species, but Zn did, and its level was associated with the mode of feeding of the species. Microphytophagous species, feeding exclusively on fungi, accumulated zinc in higher concentrations than other mites. This study illustrates the potential for bioindication by the little studied but species-rich group of soil oribatids.
- Published
- 2001
- Full Text
- View/download PDF
38. Synthesis and reactions of 2-hydroxy-5,5-dimethyl- and 2-hydroxy-5,5-pentamethylene-2-trifluoromethyltetrahydro-4-pyranones withN-nucleophiles
- Author
-
V. Ya. Sosnovskikh, E. A. Bogdanov, Andrei V. Zaitsev, and M. Yu. Mel'nikov
- Subjects
Hexane ,chemistry.chemical_compound ,chemistry ,Nucleophile ,Condensation ,Organic chemistry ,General Chemistry - Abstract
Condensation of 4-hydroxy-3,3-dimethyl- and 4-hydroxy-3,3-pentamethylenebutan-2-ones with ethyl trifluoroacetate in the presence of LiH in hexane afforded 2-hydroxy-5,5-dimethyl-and 2-hydroxy-5,5-pentamethylene-2-trifluoromethyltetrahydro-4-pyranones, whose behavior in reactions withN-nucleophiles is analogous to that of unsymmetrical polyfluorinated β-diketones.
- Published
- 1998
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- View/download PDF
39. Explicit rates of approximation in the CLT for quadratic forms
- Author
-
Friedrich Götze and Andrei Yu. Zaitsev
- Subjects
Statistics and Probability ,Dimension (graph theory) ,Central Limit theorem ,theta-series ,quadratic forms ,multidimensional spaces ,Combinatorics ,Mathematics::Probability ,concentration functions ,Fourth moment ,60F05 ,FOS: Mathematics ,Number Theory (math.NT) ,Mathematics ,Central limit theorem ,62E20 ,Mathematics - Number Theory ,Probability (math.PR) ,Zero (complex analysis) ,Order (ring theory) ,lattice point problem ,Gaussian random vector ,ellipsoids ,Covariance operator ,hyperboloids ,convergence rates ,Statistics, Probability and Uncertainty ,Random variable ,Mathematics - Probability - Abstract
Let $X,X_1,X_2,\ldots$ be i.i.d. ${\mathbb{R}}^d$-valued real random vectors. Assume that ${\mathbf{E}X=0}$, $\operatorname {cov}X=\mathbb{C}$, $\mathbf{E}\Vert X\Vert^2=\sigma ^2$ and that $X$ is not concentrated in a proper subspace of $\mathbb{R}^d$. Let $G$ be a mean zero Gaussian random vector with the same covariance operator as that of $X$. We study the distributions of nondegenerate quadratic forms $\mathbb{Q}[S_N]$ of the normalized sums ${S_N=N^{-1/2}(X_1+\cdots+X_N)}$ and show that, without any additional conditions, \[\Delta_N\stackrel{\mathrm{def}}{=}\sup_x\bigl |\mathbf{P}\bigl\{\mathbb{Q}[S_N]\leq x\bigr\}-\mathbf{P}\bigl\{\mathbb{Q}[G]\leq x\bigr\}\bigr|={\mathcal{O}}\bigl(N^{-1}\bigr),\] provided that $d\geq5$ and the fourth moment of $X$ exists. Furthermore, we provide explicit bounds of order ${\mathcal{O}}(N^{-1})$ for $\Delta_N$ for the rate of approximation by short asymptotic expansions and for the concentration functions of the random variables $\mathbb{Q}[S_N+a]$, $a\in{\mathbb{R}}^d$. The order of the bound is optimal. It extends previous results of Bentkus and G\"{o}tze [Probab. Theory Related Fields 109 (1997a) 367-416] (for ${d\ge9}$) to the case $d\ge5$, which is the smallest possible dimension for such a bound. Moreover, we show that, in the finite dimensional case and for isometric $\mathbb{Q}$, the implied constant in ${\mathcal{O}}(N^{-1})$ has the form $c_d\sigma ^d(\det\mathbb{C})^{-1/2}\mathbf {E}\|\mathbb{C}^{-1/2}X\|^4$ with some $c_d$ depending on $d$ only. This answers a long standing question about optimal rates in the central limit theorem for quadratic forms starting with a seminal paper by Ess\'{e}en [Acta Math. 77 (1945) 1-125]., Comment: Published in at http://dx.doi.org/10.1214/13-AOP839 the Annals of Probability (http://www.imstat.org/aop/) by the Institute of Mathematical Statistics (http://www.imstat.org)
- Published
- 2014
- Full Text
- View/download PDF
40. Estimates for the concentration functions in the Littlewood--Offord problem
- Author
-
Yulia S. Eliseeva, Friedrich Götze, and Andrei Yu. Zaitsev
- Subjects
Statistics and Probability ,Independent identically distributed ,Applied Mathematics ,General Mathematics ,Littlewood–Offord problem ,Probability (math.PR) ,Structure (category theory) ,Combinatorics ,Singular value ,Primary 60F05, secondary 60E15, 60G50 ,FOS: Mathematics ,Connection (algebraic framework) ,Random matrix ,Random variable ,Mathematics - Probability ,Mathematics - Abstract
Let $X,X_1,...,X_n$ be independent identically distributed random variables. In this paper we study the behavior of the concentration functions of the weighted sums $\sum\limits_{k=1}^{n}a_k X_k$ with respect to the arithmetic structure of coefficients $a_k$. Such concentration results recently became important in connection with investigations about singular values of random matrices. In this paper we formulate and prove some refinements of a result of Vershynin (R. Vershynin, Invertibility of symmetric random matrices, arXiv:1102.0300. (2011). Published in Random Structures and Algorithms, v. 44, no. 2, 135--182 (2014))., Comment: 16 pages
- Published
- 2012
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- View/download PDF
41. ChemInform Abstract: Synthesis and Reactions of 2-Hydroxy-5,5-dimethyl- and 2-Hydroxy-5,5-pentamethylene-2-trifluoromethyltetrahydro-4-pyranones with N-Nucleophiles
- Author
-
Andrei V. Zaitsev, E. A. Bogdanov, V. Ya. Sosnovskikh, and M. Yu. Mel'nikov
- Subjects
Nucleophile ,Chemistry ,Organic chemistry ,General Medicine - Published
- 2010
- Full Text
- View/download PDF
42. ChemInform Abstract: Recyclization of 2-Amino- and 2-Methylamino-2-trifluoromethyl-5,5-dimethyltetrahydro-4-pyrone Oximes to 5-Amino- and 5-Methylamino-5-trifluoromethyl-3- (2-hydroxy-1,1-dimethylethyl)-Δ2-isoxazolines
- Author
-
Vyacheslav Ya. Sosnovskikh, Andrei V. Zaitsev, and Mikhail Yu. Mel’nikov
- Subjects
chemistry.chemical_compound ,Trifluoromethyl ,chemistry ,General Medicine ,4-Pyrone ,Medicinal chemistry - Published
- 2010
- Full Text
- View/download PDF
43. The $\bm{L}_\mathbf{1}$-norm density estimator process
- Author
-
David M. Mason, Andrei Yu. Zaitsev, and Evarist Giné
- Subjects
Statistics and Probability ,Pure mathematics ,Kernel density function estimator ,Weak convergence ,Poissonization ,Mathematical analysis ,central limit theorem ,Estimator ,Limiting ,$L_{1}$-norm ,Lebesgue integration ,weak convergeance ,symbols.namesake ,60F17 ,60F05 ,Chaining ,62G07 ,symbols ,60F15 ,Statistics, Probability and Uncertainty ,entropy ,Gaussian process ,Mathematics ,Central limit theorem - Abstract
The notion of an $L_{1}$-norm density estimator process indexed by a class of kernels is introduced. Then a functional central limit theorem and a Glivenko--Cantelli theorem are established for this process. While assembling the necessary machinery to prove these results, a body of Poissonization techniques and restricted chaining methods is developed, which is useful for studying weak convergence of general processes indexed by a class of functions. None of the theorems imposes any condition at all on the underlying Lebesgue density $f$. Also, somewhat unexpectedly, the distribution of the limiting Gaussian process does not depend on $f$.
- Published
- 2003
- Full Text
- View/download PDF
44. Successional changes of Collembola and soil microbiota during forest rotation
- Author
-
Andrei S. Zaitsev, Volkmar Wolters, and Matthieu Chauvat
- Subjects
Biomass (ecology) ,Food Chain ,Insecta ,Ecology ,Chronosequence ,Soil organic matter ,Population Dynamics ,Community structure ,Forestry ,Biology ,Food web ,Decomposer ,Trees ,Forest ecology ,Soil food web ,Animals ,Picea ,Ecology, Evolution, Behavior and Systematics ,Soil Microbiology - Abstract
Dynamic approaches to forest ecosystems are surprisingly rare. Here we report about successional changes in collembolan community structure and microbial performances during forest rotation. The study was carried out in a chronosequence of four spruce forest stands (5-, 25-, 45-, and 95 years old; Tharandter forest, Germany). CO2 release significantly increased after clear-cutting and the amount of C stored in the organic layer subsequently declined. The early phase of forest rotation was characterized by a very active decomposer microflora, stimulation of both fungi and bacteria as well as by a high abundance of surface-oriented Collembola. In addition, collembolan species turnover was accelerated. While the biomass of fungi further increased at intermediate stages of forest rotation, the metabolic activity of the microflora was low, the functional diversity of bacteria declined and the collembolan community became impoverished. Euedaphic species dominated during this stage of forest development. These changes can be explained by both reduction in microhabitat diversity and depletion of food sources associated with an accumulation of recalcitrant soil organic matter. Results of the General Regression Model procedure indicate a shift from specific associations between collembolan functional groups and microbiota at the early stage of forest rotation to a more diffuse pattern at intermediate stages. Though the hypothesis that Collembola are relatively responsive to changes in environmental conditions is confirmed, consistently high community similarity suggests a remarkable persistence of some components of microarthropod assemblages. Our study provides evidence for substantial ecosystem-level implications of changes in the soil food web during forest rotation. Moreover, correlations between bacterial parameters and Collembola point to the overarching impact of differences in the composition of the microbial community on microarthropods.
- Published
- 2003
45. Estimates of the Rate of Approximation in the CLT for L 1-Norm of Density Estimators
- Author
-
Andrei Yu. Zaitsev
- Subjects
symbols.namesake ,Variable kernel density estimation ,Bounded function ,Kernel (statistics) ,Poisson point process ,Statistics ,Kernel density estimation ,symbols ,Applied mathematics ,Estimator ,Poisson distribution ,Central limit theorem ,Mathematics - Abstract
We estimate the rate of strong approximation and probabilities of moderate deviations in the CLT for the L1-norm of the kernel density estimator under no assumptions at all on the density and assuming that the kernel is bounded and has bounded support.
- Published
- 2003
- Full Text
- View/download PDF
46. Metal concentrations in soil and invertebrates in the vicinity of a metallurgical factory near Tula (Russia)
- Author
-
Nico M. van Straalen, Ruslan O. Butovsky, A. D. Pokarzhevskii, S. Cornelis Verhoef, Andrei S. Zaitsev, and Animal Ecology
- Subjects
chemistry.chemical_classification ,Pollution ,Cadmium ,Ecology ,media_common.quotation_subject ,Soil Science ,chemistry.chemical_element ,Zinc ,chemistry ,Environmental chemistry ,Soil water ,Litter ,Environmental science ,Organic matter ,Ecology, Evolution, Behavior and Systematics ,Trophic level ,media_common ,Invertebrate - Abstract
Summary To investigate the effects of emissions from a large metal works near Tula in the Russian Federation, we measured concentrations of iron, manganese, zinc, copper, nickel, lead and cadmium in soil, litter and invertebrates at four sampling sites at different distances from the factory. The sites were located in woodlands in the bed of the Voronka river, near the town of Kosaya Gora in the district of Tula. Additional soil properties (organic matter content, clay content, water holding capacity, Ca, Mg, N, P, and pH) were measured that could explain differences in the bioavailability of the metal burdens. It appeared that the factory is a source of Fe, Mn, Zn, Cu, Ni and Pb. One of the sampling sites had a high nitrogen content in the litter due to emissions from a fertilizer plant in the area. Most of the metal contamination was limited to the immediate surroundings and did not extend beyond a distance of 5 km. Only the site close to the factory can be considered as polluted, however, background concentrations of metals in the Tula area seem to be significantly lower than in present Western European soils and a reference system still has to be developed. Exchangeable metal concentrations (0.01 M CaCl 2 extracts from soil) were very low and were not correlated with the total concentrations, indicating low bioavailability of the pollution. At the most polluted site, concentrations of all metals were positively correlated with each other; correlations decreased with increasing distance. Metal concentrations in soil were often negatively correlated with organic matter content, especially so for nickel. Metal concentrations in invertebrates showed considerable variation between individual species, however, some general patterns were obvious. Concentrations were high in earthworms, oribatid mites and carabid beetles, and low in springtails, centipedes and spiders. There was no relationship between the trophic position of a species and its metal accumulating ability. Iron concentrations in invertebrates at the polluted site were a factor of 2 to 4 higher than at the most remote (reference) site; for zinc and copper the internal concentrations were also elevated, but to a lesser extent than the soil concentrations. The data illustrate the extremely complicated relationship between metal residues in invertebrates and metal concentrations in soil. For most of the saprophageous and predatory arthropods studied total concentrations nor exchangeable concentrations in soil are good predictors; species-specific feeding mechanisms and metal physiologies seem to be the main determinants.
- Published
- 2001
- Full Text
- View/download PDF
47. A Multiplicative Inequality for Concentration Functions of n-Fold Convolutions
- Author
-
Andrei Yu. Zaitsev and Friedrich Götze
- Subjects
Discrete mathematics ,Inequality ,Fold (higher-order function) ,media_common.quotation_subject ,Bounded function ,Multiplicative function ,Concentration function ,Central limit theorem ,Probability measure ,media_common ,Mathematics - Abstract
We estimate the concentration functions of n-fold convolutions of one-dimensional probability measures. The main result is a supplement to the results of Gotze and Zaitsev (1998). We show that the estimation of concentration functions at arguments of bounded size can be reduced to the estimation of these functions at arguments of size \(O\left( {\sqrt n } \right)\) which is easier.
- Published
- 2000
- Full Text
- View/download PDF
48. Oribatid mite communities (Acari: Oribatida) in different habitats of the Polistovsky Nature Reserve (Pskov Region, Russia)
- Author
-
Andrei S. Zaitsev
- Subjects
Nature reserve ,Ecology ,Habitat ,biology ,Abundance (ecology) ,Fauna ,Community structure ,Mite ,Rank abundance curve ,biology.organism_classification ,Oribatida ,Ecology, Evolution, Behavior and Systematics - Abstract
The fauna and community structure of oribatid mites (Acari: Oribatida) in the Pskov Region of Russia is not yet comprehensively studied. Until now not much attention has been paid to soil communities of bogs and open landscapes of this area. The aim of this study was to compare the community composition of oribatid mites in different habitats in the environs of the Polistovsky National Nature Reserve (Pskov Region, Russia). We found 56 oribatid species in this area during our sampling campaign in 2010. Of these 16 have not been recorded in the Pskov Region before. Forest habitats were the richest in species within the examined territory. The highest faunistic similarity of oribatid communities was found between raised bogs and transition bogs. The mite faunistic composition in these two types of habitats was in turn quite similar to that in spruce forests. At the same time secondary habitats such as meadows hosted fewer oribatid species and were faunsitically distinct from the other habitats. Analysis of the rank abundance distribution of oribatid species indicated a disturbed state of oribatid communities in meadows even after their abandonment 20-25 years ago. The abundance of all oribatid ecomorphs besides surface-dwelling mites was similar and not significantly different across habitats. We assume that the relatively high number of previously unrecorded oribatid species for the Pskov Region in the research area is related to the considerable age of landscapes in the Polistovsko-Lovatskaya peat bog system and immigration of oribatid mites with transiting birds. More detailed comparative study of the oribatid fauna and community structure in the Polistovsky Reserve is needed to discover driving forces of the revealed community structure and diversity.
- Published
- 2013
- Full Text
- View/download PDF
49. Recyclization of 2-amino- and 2-methylamino-2-trifluoromethyl-5,5-dimethyl- tetrahydro-4-pyrone oximes to 5-amino- and 5-methylamino-5-trifluoromethyl-3-(2-hydroxy-1,1-dimethylethyl)-Δ2-isoxazolines
- Author
-
Mikhail Yu. Mel’nikov, Vyacheslav Ya. Sosnovskikh, and Andrei V. Zaitsev
- Subjects
chemistry.chemical_compound ,Ethanol ,Trifluoromethyl ,Hydroxylamine ,chemistry ,Yield (chemistry) ,Organic chemistry ,General Chemistry ,4-Pyrone - Abstract
The reactions of hydroxylamine with 2-amino- and 2-methylamino-2-trifluoromethyl-5,5-dimethyltetrahydro-4-pyrones yield 2-amino- and 2-methylamino-2-trifluoromethyl-5,5-dimethyltetrahydro-4-pyrone oximes, which can be converted to 5-amino- and 5-methyl-amino-5-trifluoromethyl-3-(2-hydroxy-1,1-dimethylethyl)-Δ2-isoxazolines, respectively, by heating in ethanol.
- Published
- 1999
- Full Text
- View/download PDF
50. Approximation of quadratic forms of independent random vectors by accompanying laws
- Author
-
Andrei Yur'evich Zaitsev, Friedrich Götze, and Vidmantas Yu Bentkus
- Subjects
Hilbert spaces ,Statistics and Probability ,Discrete mathematics ,Pure mathematics ,Mathematical analysis ,compound Poisson approximation ,accompanying laws ,quadratic forms ,multidimensional spaces ,Combinatorics ,ellipsoids ,Covariance operator ,Common distribution ,hyperboloids ,convergence rates ,Statistics, Probability and Uncertainty ,Mathematics - Abstract
Let X, X1 , X2 ,... be independent and identically distributed random vectors taking values in Rd . Assume that EX =0, E|X|8/3
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