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  1. Article: Electrochemical Mechanism of Oxidative Dissolution of Silver Nanoparticles in Water: Effect of Size on Electrode Potential and Solubility.

    Ershov, Boris / Ershov, Vadim

    Nanomaterials (Basel, Switzerland)

    2023  Volume 13, Issue 13

    Abstract: For the first time, an electrochemical mechanism of oxidative dissolution of silver nanoparticles in aqueous solutions is suggested and substantiated. The dissolution is caused by the occurrence of two interrelated electrochemical processes: (1) silver ... ...

    Abstract For the first time, an electrochemical mechanism of oxidative dissolution of silver nanoparticles in aqueous solutions is suggested and substantiated. The dissolution is caused by the occurrence of two interrelated electrochemical processes: (1) silver oxidation on a microanode and (2) oxygen reduction on a microcathode. According to the suggested model, the standard electrode potential of a nanoparticle decreases with a decrease in its size, which leads to an increase in the electromotive force of the oxidative dissolution of silver. A proportional dependence of the solubility of nanoparticles on their standard potential is revealed. An empirical equation is derived that relates the solubility of AgNPs to their electrode potential and size. In the course of oxidation, silver nanoparticles undergo aggregation with a gradual increase in the potential to the value characteristic of the bulk metal. This leads to the deceleration and practical cessation of the dissolution.
    Language English
    Publishing date 2023-06-22
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2662255-5
    ISSN 2079-4991
    ISSN 2079-4991
    DOI 10.3390/nano13131907
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Natural Radioactivity and Chemical Evolution on the Early Earth: Prebiotic Chemistry and Oxygenation.

    Ershov, Boris

    Molecules (Basel, Switzerland)

    2022  Volume 27, Issue 23

    Abstract: It is generally recognized that the evolution of the early Earth was affected by an external energy source: radiation from the early Sun. The hypothesis about the important role of natural radioactivity, as a source of internal energy in the evolution of ...

    Abstract It is generally recognized that the evolution of the early Earth was affected by an external energy source: radiation from the early Sun. The hypothesis about the important role of natural radioactivity, as a source of internal energy in the evolution of the early Earth, is considered and substantiated in this work. The decay of the long-lived isotopes
    Language English
    Publishing date 2022-12-05
    Publishing country Switzerland
    Document type Journal Article ; Review
    ZDB-ID 1413402-0
    ISSN 1420-3049 ; 1431-5165 ; 1420-3049
    ISSN (online) 1420-3049
    ISSN 1431-5165 ; 1420-3049
    DOI 10.3390/molecules27238584
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    In stock of ZB MED Cologne/Königswinter

    Zs.MO 81: Show issues

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  3. Book ; Online: A Case Study for Compliance as Code with Graphs and Language Models

    Ershov, Vladimir

    Public release of the Regulatory Knowledge Graph

    2023  

    Abstract: The paper presents a study on using language models to automate the construction of executable Knowledge Graph (KG) for compliance. The paper focuses on Abu Dhabi Global Market regulations and taxonomy, involves manual tagging a portion of the ... ...

    Abstract The paper presents a study on using language models to automate the construction of executable Knowledge Graph (KG) for compliance. The paper focuses on Abu Dhabi Global Market regulations and taxonomy, involves manual tagging a portion of the regulations, training BERT-based models, which are then applied to the rest of the corpus. Coreference resolution and syntax analysis were used to parse the relationships between the tagged entities and to form KG stored in a Neo4j database. The paper states that the use of machine learning models released by regulators to automate the interpretation of rules is a vital step towards compliance automation, demonstrates the concept querying with Cypher, and states that the produced sub-graphs combined with Graph Neural Networks (GNN) will achieve expandability in judgment automation systems. The graph is open sourced on GitHub to provide structured data for future advancements in the field.

    Comment: 7 pages on RegKG step 1 in collaboration with ADGM
    Keywords Computer Science - Artificial Intelligence ; Computer Science - Computation and Language ; Computer Science - Information Retrieval ; Computer Science - Machine Learning ; I.2.1 ; I.2.4 ; J.1
    Subject code 006
    Publishing date 2023-02-03
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Electrochemical Mechanism of Oxidative Dissolution of Silver Nanoparticles in Water

    Boris Ershov / Vadim Ershov

    Nanomaterials, Vol 13, Iss 1907, p

    Effect of Size on Electrode Potential and Solubility

    2023  Volume 1907

    Abstract: For the first time, an electrochemical mechanism of oxidative dissolution of silver nanoparticles in aqueous solutions is suggested and substantiated. The dissolution is caused by the occurrence of two interrelated electrochemical processes: (1) silver ... ...

    Abstract For the first time, an electrochemical mechanism of oxidative dissolution of silver nanoparticles in aqueous solutions is suggested and substantiated. The dissolution is caused by the occurrence of two interrelated electrochemical processes: (1) silver oxidation on a microanode and (2) oxygen reduction on a microcathode. According to the suggested model, the standard electrode potential of a nanoparticle decreases with a decrease in its size, which leads to an increase in the electromotive force of the oxidative dissolution of silver. A proportional dependence of the solubility of nanoparticles on their standard potential is revealed. An empirical equation is derived that relates the solubility of AgNPs to their electrode potential and size. In the course of oxidation, silver nanoparticles undergo aggregation with a gradual increase in the potential to the value characteristic of the bulk metal. This leads to the deceleration and practical cessation of the dissolution.
    Keywords nanoparticles ; silver ; dissolution ; solubility ; electrochemical mechanism ; standard potential ; Chemistry ; QD1-999
    Subject code 500
    Language English
    Publishing date 2023-06-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  5. Article ; Online: Natural Radioactivity and Chemical Evolution on the Early Earth

    Boris Ershov

    Molecules, Vol 27, Iss 8584, p

    Prebiotic Chemistry and Oxygenation

    2022  Volume 8584

    Abstract: It is generally recognized that the evolution of the early Earth was affected by an external energy source: radiation from the early Sun. The hypothesis about the important role of natural radioactivity, as a source of internal energy in the evolution of ...

    Abstract It is generally recognized that the evolution of the early Earth was affected by an external energy source: radiation from the early Sun. The hypothesis about the important role of natural radioactivity, as a source of internal energy in the evolution of the early Earth, is considered and substantiated in this work. The decay of the long-lived isotopes 232 Th, 238 U, 235 U, and 40 K in the Global Ocean initiated the oxygenation of the hydro- and atmosphere, and the abiogenesis. The content of isotopes in the ocean and the kinetics of their decay, the values of the absorbed dose and dose rate, and the efficiency of sea water radiolysis, as a function of time, were calculated. The ocean served as both a “ reservoir ” that collected components of the early atmosphere and products of their transformations, and a “ converter ” in which further chemical reactions of these compounds took place. Radical mechanisms were proposed for the formation of simple amino acids, sugars, and nitrogen bases, i.e., the key structures of all living things, and also for the formation of oxygen. The calculation results confirm the possible important role of natural radioactivity in the evolution of terrestrial matter, and the emergence of life.
    Keywords early earth ; ocean ; radioactivity ; radiolysis ; chemical evolution ; prebiotic molecules ; Organic chemistry ; QD241-441
    Subject code 333
    Language English
    Publishing date 2022-12-01T00:00:00Z
    Publisher MDPI AG
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  6. Article: Determination of the Concentration of Silver Atoms in Hydrosol Nanoparticles.

    Abkhalimov, Evgeny / Ershov, Vadim / Ershov, Boris

    Nanomaterials (Basel, Switzerland)

    2022  Volume 12, Issue 18

    Abstract: In this work, we propose a new method for determining the concentration of silver atoms in hydrosols of nanoparticles (NPs) stabilized with various capping agents. The proposed method is based on the determination of IBT absorption in the UV region (a ... ...

    Abstract In this work, we propose a new method for determining the concentration of silver atoms in hydrosols of nanoparticles (NPs) stabilized with various capping agents. The proposed method is based on the determination of IBT absorption in the UV region (a broad band with a weakly pronounced shoulder at ~250 nm). To determine the extinction coefficient at 250 nm, we synthesized silver nanoparticles with average sizes of 5, 10, and 25 nm, respectively. The prepared nanoparticles were characterized by TEM, HRTEM, electron diffraction, XRD, DLS, and UV-Vis spectroscopy. It has been shown that the absorption characteristics of spherical NPs are not significantly influenced by the hydrosol preparation method and the type of stabilizer used. For particles with a size of 5-25 nm, the molar extinction coefficient of Ag0 atoms was found to be equal to 3500 ± 100 L mol
    Language English
    Publishing date 2022-09-06
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2662255-5
    ISSN 2079-4991
    ISSN 2079-4991
    DOI 10.3390/nano12183091
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  7. Article ; Online: New 2-pyridone-based donor-acceptor dyes: the effect of the donor group position, type of π-linker and acid-base characteristics of the medium on the photophysical properties.

    Sorokin, Saveliy P / Ievlev, Mikhail Yu / Ershov, Oleg V

    Organic & biomolecular chemistry

    2024  Volume 22, Issue 17, Page(s) 3468–3476

    Abstract: A series of novel donor-acceptor pyrid-2-ones was synthesized. The influence of the donor group on the photophysical properties of chromophores in solution was shown by varying the methoxy group position in the electron-rich aromatic ring. The effect of ... ...

    Abstract A series of novel donor-acceptor pyrid-2-ones was synthesized. The influence of the donor group on the photophysical properties of chromophores in solution was shown by varying the methoxy group position in the electron-rich aromatic ring. The effect of the π-linker was also demonstrated by the comparison of the D-π-A pyridone with its spacer-free analogue (D-A) and with the chromophore bearing an additional thiophene bridge (D-π-π-A). It was found that the presence of a π-linker plays a crucial role in the implementation of an intramolecular charge transfer (ICT) from the donor aryl moiety to the pyridone acceptor. Thus, for the synthesized D-A, D-π-A and D-π-π-A derivatives, the photoluminescence quantum yield in DMSO solution decreases from 56.8 to 4.3 and 3.5%, respectively, along with a strong bathochromic shift both for absorption (66 nm) and emission (162 nm) bands. Also, the possibility of shifting the equilibrium in DMSO solution towards either the pyridone form or the anionic form by the addition of a strong acid (TFA) and base (DBN) respectively was shown. Drastic changes in the photoluminescence of the solutions showed prospects for the application of the synthesized donor-acceptor pyridone derivatives as naked-eye acid-base indicators in organic media.
    Language English
    Publishing date 2024-05-01
    Publishing country England
    Document type Journal Article
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/d4ob00177j
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  8. Article ; Online: Tax resident status

    Berman Alisa / Ershov Nikita

    BIO Web of Conferences, Vol 84, p

    approaches to determination and consequences of its loss by an individual

    2024  Volume 05010

    Abstract: This article deals with approaches to the definition of the concept of tax residency and legal consequences of the loss of tax residency status by an individual. The article analyzes the main types of tax jurisdictions, as well as the criteria of tax ... ...

    Abstract This article deals with approaches to the definition of the concept of tax residency and legal consequences of the loss of tax residency status by an individual. The article analyzes the main types of tax jurisdictions, as well as the criteria of tax residency applied in different states. In the course of the analysis the authors consider examples of specific acts of national and international regulation, as well as relevant law enforcement practice. Special attention is paid to reasons for the loss of tax residency status, as well as the main (most significant) consequences of such loss and some related aspects.
    Keywords Microbiology ; QR1-502 ; Physiology ; QP1-981 ; Zoology ; QL1-991
    Language English
    Publishing date 2024-01-01T00:00:00Z
    Publisher EDP Sciences
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article: Retrospective Cohort Study of the Effectiveness of the Sputnik V and EpiVacCorona Vaccines against the SARS-CoV-2 Delta Variant in Moscow (June-July 2021).

    Matveeva, Olga / Ershov, Alexander

    Vaccines

    2022  Volume 10, Issue 7

    Abstract: The goal of this study was to evaluate the epidemiological effectiveness of the Sputnik V and EpiVacCorona vaccines against COVID-19. This work is a retrospective cohort study of COVID-19 patients. The cohort created by the Moscow Health Department ... ...

    Abstract The goal of this study was to evaluate the epidemiological effectiveness of the Sputnik V and EpiVacCorona vaccines against COVID-19. This work is a retrospective cohort study of COVID-19 patients. The cohort created by the Moscow Health Department included more than 300,000 infected people who sought medical care in June and July 2021. Analysis of data revealed a tendency for the increase in the Sputnik V vaccine effectiveness (VE) as the severity of the disease increased. Protection was the lowest for mild disease, and it was more pronounced for severe disease. We also observed a decrease in VE with increasing age. For the youngest group (18-50 years old), the estimated VE in preventing death in June 2021 was 95% (95% CI 64-100), and for the older group (50+ years old), it was 74% (95% CI 67-87). The estimated protection against a severe form of the disease in the 18-50-year-old group was above 81% (CI 95% 72-93), and in the 50+ years-old group, it was above 68% (CI 95% 65-82). According to our analysis, EpiVacCorona proved to be an ineffective vaccine and therefore cannot protect against COVID-19.
    Language English
    Publishing date 2022-06-21
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2703319-3
    ISSN 2076-393X
    ISSN 2076-393X
    DOI 10.3390/vaccines10070984
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  10. Article: The synthesis of

    Sorokin, Saveliy P / Ershov, Oleg V

    Chemistry of heterocyclic compounds

    2022  Volume 58, Issue 11, Page(s) 582–584

    Abstract: This microreview compiles methods for the synthesis ... ...

    Abstract This microreview compiles methods for the synthesis of
    Language English
    Publishing date 2022-11-30
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2037128-7
    ISSN 1573-8353 ; 0009-3122
    ISSN (online) 1573-8353
    ISSN 0009-3122
    DOI 10.1007/s10593-022-03132-4
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