bluuebunny/crossref_metadata_2025 huggingface dataset:
A new species of the genus Hydrobaenus Fries, 1830 (Diptera: Chironomidae) from the Arctic Russia
Authors:   Institute of Biological Problems of the North Far East Branch of the Russian Academy of Sciences, Portovaya St. 18, Magadan, 685000, Russia, Krasheninnikov A.B. , Vshivkova K. A. ,   Institute of Biological Problems of the North Far East Branch of the Russian Academy of Sciences, Portovaya St. 18, Magadan, 685000, Russia
Published: May 2022

Hydrobaenus birulyai Krasheninnikov, sp. n. is described based on adult males from Yugorsky Peninsula. The new species is similar to H. tumidistylus Sæther, 1976 but differs from latter by long, wide at apex and rounded anal point without microtrichia, by present of 16 weak acrostichals begin at some distance from antepronotum, by massive inferior volsella, and by gonostylus with large median lobe located medially.
Manejo das lesões cutâneas de um recém-nascido com suspeita epidermólise bolhosa: um relato de experiência
Authors: Vieira Géssica Borges , Neta Olinda da Silva Oliveira , Santos Suzana Oliveira , Dutra Jaqueline Rodrigues , Coelho Roberta Rodrigues , Pommerehn Jodéli , Dantas Esther Luiza de Morais Medeiros , Gomes Giovana Calcagno
Published: May 2022

Objetivo: Relatar a experiência de profissionais de saúde no manejo das lesões cutâneas de um recém-nascido com suspeita de Epidermólise Bolhosa. Relato da experiência: Trata-se de um relato de experiência, desenvolvido de março a abril de 2021 por profissionais de um Hospital Universitário do Sul do Brasil. Os dados emergiram dos relatos, observações, reuniões, estudos individuais e assessoria externa. Realizou-se o manuseio mínimo do recém-nascido. Priorizou-se a prevenção da formação de novas bolhas. O tratamento das lesões no início foi com antibiótico tópico por estarem infectadas e, após, com curativos com tela de malha impregnada com parafina embebida em vaselina e cobertos por ataduras e, posteriormente, em lipídio colóide e coberto por malha tubular elástica. Foi dada atenção à dor e a orientação familiar para o cuidado. Considerações finais: Para assistência ao recém-nascido com Epidermólise Bolhosa é necessário um cuidado interdisciplinar, individualizado e holístico com ênfase no tratamento e prevenção das lesões bolhosas, além disso, deve ser dado atenção a dor e ao apoio à família.
Diş Eti Fenotipi ve Diş Hekimliğinde Oynadığı Rol
Authors: HATİPOĞLU Hasan , GÜNGÖR HATİPOĞLU Müjgan
Published: May 2022

Diş eti taşıdığı kendine has özellikleri ile oral yapının önemli temel yapı taşlarından birini oluşturmaktadır. Literatür incelendiğinde diş eti fenotipinin farklı şekillerde tanımlandığı görülmektedir. Her tanımlamanın kendine has özellikleri ve kendine has avantaj ve dezavantajları vardır. Bu tanımlama girişimsel ve girişimsel olmayan yöntemler ile yapılmaktadır. Klinikte izlenen diş eti yapısının beraberinde getirdiği olumlu-olumsuz yönleri bulunmaktadır. Diş eti yapısı; yaş, cinsiyet, alveoler kemik yapısı, diş yapısı, yüz yapısı, ortodontik durumlar gibi durumlarda değişiklik göstermektedir. Ama halen birçok konuda ve terminolojide bir görüş birliği sağlanamamıştır. Periodontal, restoratif, protetik ve implant uygulamalarında diş eti yapısı önem kazanmaktadır. Bu derlemede diş eti fenotipi tartışılacak olup, fenotipin klinik uygulamalarda oynadığı rol üzerinde durulacaktır.
A New Combination Procedure for the Word Problem that Generalizes Fusion Decidability Results in Modal Logics
Authors:   Institut für Theoretische Informatik, TU Dresden, Baader Franz , Ghilardi Silvio ,   Dipartimento di Scienze dell’Informazione Università degli Studi di Milano, Tinelli Cesare ,   Department of Computer Science, The University of Iowa
Published: May 2022

Previous results for combining decision procedures for the word problem in the non-disjoint case do not apply to equational theories induced by modal logics - which are not disjoint for sharing the theory of Boolean algebras. Conversely, decidability results for the fusion of modal logics are strongly tailored towards the special theories at hand, and thus do not generalize to other types of equational theories. In this paper, we present a new approach for combining decision procedures for the word problem in the non-disjoint case that applies to equational theories induced by modal logics, but is not restricted to them. The known fusion decidability results for modal logics are instances of our approach. However, even for equational theories induced by modal logics our results are more general since they are not restricted to so-called normal modal logics.
The sequence and directions of doing business in the market
Authors: Zemlyanskiy O. A.
Published: May 2022

Entrepreneurial activity, its types and methods of action in the markets are very diverse. Markets also have great differences, features or specifics, therefore, a comparative analysis of the feasibility of entering or presence in them requires not only the calculation of economic indicators, but also the development of a single sequence and lines of business for any market, type and scale of business, allowing an analysis of the possibility of effective conducting different types of business, occupying desired positions in the market, compare these business opportunities in different markets. A sequence of interrelated actions and directions of entrepreneurial activity in the market, their structure and description, which are common for any type of business, are proposed, which allow analyzing the state, functioning and possibility of developing any type of business in any market, determining the feasibility of entering the market or being present on it.
Analysis and assessment of the organisation’s internal control risks
Authors: Kirovа E. A. , Perminova T. V.
Published: May 2022

Risk management is an important part of an organisation’s internal controls and needs to be adjusted in response to changes in the external environment. In this article the problem of risk prevention and loss reduction in the organisation’s internal control system has been solved in the current environment. The existing risks were analysed and described, classification of external and internal risks was developed and methodology of risk tolerance and possibility of diversification was proposed. It was proved that the proposed risk matrix gives a clear picture of risky operations and helps organisations to implement response measures, optimising the risks. The proposed methodology is tested in a specific organisation. The study uses the methods of systematic approach, analysis and synthesis, abstraction and generalisation.
Assessing the impact of the country’s economic security on export development in the agro-industrial sector
Authors: Nagovitsyna E. V. , Bratukhina E. A.
Published: May 2022

While the conditions of the world markets functioning factors change, it is required the development of a new effective strategy for food security in the Russian Federation. The global economic shock caused by the COVID-19 pandemic, changes in the structure and volume of world trade, and political crises in a number of EAEU member states also force us to pay special attention to food security. The relevance of this research is due to: 1) the processes of globalisation and integration of national markets, which is why new foreign economic and foreign trade relations are increasingly being formed; 2) the crisis of the coronavirus pandemic, which is why many foreign trade processes in Russia and a number of other countries are disrupted; 3) the commodity groups under consideration, the uncontrolled volume of exports of which can cause a food threat to the country. The purpose of the study is to analyse the problems of assessing food security within the country in the implementation of foreign economic activity and the supply of agro-industrial complex goods to foreign markets. The objectives of the study are to identify ways to assess food security. Measurement tools are proposed that help to assess food security at the national level, assess household access to food and its purchase, and also allow measuring food consumption and use. To date, the solution of this problem is one of the main tasks, both within individual regions and the country as a whole.
The economics of the performing arts before and during the COVID-19 pandemic. Part 2: an investment approach to cultural enents
Authors: Morozova D. L.
Published: May 2022

The article demonstrates the possibilities of corporate governance methods and investment decision-making models for the cultural organizations and events (on the examples of federal theaters). Financial and investment analysis was applied in the study. The article discusses the hypothesis of the possibility of balancing budgets for new theatrical productions, taking the rehearsal period, premiere and running as a whole. The productions are not considered as deadweight losses, but are analysed as assets with risky returns. The results of the financial analysis of the staging activities of the leading theaters demonstrate their limited possibilities in balancing the budgets for new productions. The most popular performance (with an average ticket price above the market and a stable occupancy rate of over 90 %) requires at least 5–6 years of active running to recoup the initial investment. The author’s are expected to help the performing arts organizations to identify and assess losses during the pandemic crisis. The scientific novelty is to the approach to calculating and forecasting the return on production costs.
Customs institutions development strategy: design and implementation issues
Authors: Makrusev V. V.
Published: May 2022

Today, quality requirements for customs administration are increasing, but customs technology is not sufficiently productive: with the accumulated experience of solving management tasks, there is no modern, unified methodological support for strategic planning in this area. There is an urgent need to develop and implement a new concept, strategy or development programme for the Federal Customs Service of the Russian Federation in the context of quantitative and expert forecasts for the long term. The aim of the study was to analyse the existing approaches and methodological support used to research and develop strategic planning documents on national (economic) security of the Russian Federation, and to substantiate proposals and approaches to the design of strategies and programmes for the development of public administration and administration institutions in terms of foreign economic and customs activities. The methodological basis of the study was a comparative analysis of Russian and foreign experience in addressing development challenges in the customs sphere. On the basis of the generalised experience of theoretical approaches, recommendations and practices of strategic planning documents development the qualitative expertise of the structure of key normative-legal documents, on the basis of which the customs authorities carry out their activities, has been carried out. The problem areas of the process of design and modernization of the structure of documents in the field of customs administration are identified and recommendations for their adjustment are presented. It is proposed to apply intelligent systems of computer-aided designing and to transit from model of static designing of customs institutions to model of operative controlling of spheres of foreign economic and customs activity and dynamic (continuous) designing of customs systems on principles of self-organisation and self-development.
Development of long-term financing of innovative small companies
Authors: Morozko N. I. , Morozko N. I.
Published: May 2022

The subject of the research is financial relations in the process of financing innovative small companies. The purpose of the work is an analytical assessment of the conditions for long-term financing of innovative small companies using systematic, economic and statistical analysis, which ensures the integrity and comprehensiveness of the study. Increasing the role of innovative small companies in the process of digital transformations is an urgent task in modern transformations of society. The analysis revealed the problems of long-term financing of innovative small companies, since most of the methods are focused on short-term financing of such companies. The conditions of investment opportunities for innovative companies are considered in detail on specific examples. The article notes that the conditions for effective management of long-term investments depend on the various stages of development of innovative companies. The practical purpose and scientific value of the article lies in the construction of a holistic and logical representation of the use of various methods of financing high-tech companies. It is concluded that it is necessary to provide institutional financial support for innovative development and an integrated approach to long-term financing of innovative small companies.
Hypersthetic reactions and actual self-perception students at the stage of self-isolation during the COVID-19 pandemic
Authors: Basimov M. M. , Tsvetkova N. A.
Published: May 2022

The article contains the results of a survey of Moscow students of both sexes during the quarantine period associated with the COVID-19 pandemic. Hypersthetic reactions and self-perception were studied. It is shown that the proportion of students with a high overall level of hypersthetic reactions was 5.8 %, with an average – 27.5 %, with a low – 66.7 %. All private indicators of this parameter are registered in the low range of values with a tendency to the average level. The most pronounced reaction turned out to be “paying attention to different situations, events or stimuli that I had completely ignored before.” The results of a comparative analysis of data by gender are presented; girls have a significantly higher overall level of hypersthetic reactions. All indicators of actual self-perception turned out to be moderately pronounced, indicating its adequacy. Intersex differences were found in the assessments of “free” and “healthy”. Attention was drawn to the fact that the Pearson correlation analysis did not show a connection between hypersthetic reactions and self-perception - they were identified using the method of statistical relationships research within the framework of the synergetic approach and the nonlinear psychology of M.M. Basimov.
Experience of organizing foster families for elderly citizens in the subjects of the Russian Federation
Authors: Sadykov R. M. , Bolshakova N. L.
Published: May 2022

The article discusses a special and effective form of living arrangements for the elderly and disabled in a foster family in the regional entities of the Russian Federation. The experience of organizing a foster or substitute family has been developed in a number of European countries and the USA. It has been established that this technology provides an elderly person with the necessary care and living conditions, leisure activities, psychological support, and additional material support for a foster family. The development of the institution of a foster family for the elderly as an innovative form of their life arrangement will significantly improve the quality of life of older citizens, change their “social well-being”, save them from the problem of loneliness, and strengthen the connection between generations. To solve the problems of the elderly in 2004, the project “Foster families for the elderly and disabled” was launched. The mission of this project is to organize public support, help with household chores and psychological support for lonely people. Most of the regions of the Russian Federation supported the initiative of the project and the subjects have their own experience in implementing the Foster Families for Senior Citizens project. Each subject of the Russian Federation has its own characteristics and differences in the creation of foster families for the elderly, which is associated with the presence of its own legislative framework for the implementation of this project.
Teal organizations in the eyes of generation Z: Implementation problems in Russia
Authors: Nechvoloda E. A. , Matveeva J. V.
Published: May 2022

Basic concepts related to analysis and evaluation of teal organizations are reviewed, and generation Z’s attitude to the teal organizations implementation in Russia. Article analyses the classification and basic principles of teal organizations. Regional and federal organizations were reviewed as examples for research implementation. Authors have interviewed Samara University students with their own developed form as part of the research. With the students’ answers, the youth’s attitude to implementation of teal organizations has been determined and classified. The research data could be used not only for the determination of teal organizations’ key qualities mostly valuable for generation Z, but for the determination of key qualities for competent organization of common-typed enterprises by entrepreneurs.
Problems of training competitive higher education graduates in today’s environment
Authors: Ryazanova G. N.
Published: May 2022

One of the drivers of economic development is human capital, which can transform the economic space and reveal the innovative potential of the socio-economic landscape’s systems and subsystems. The key role in shaping the human resources of the future belongs to the higher school. Current institutional conditions impose new requirements on graduates of higher educational institutions and to the higher education system, in particular, to university teachers. Purpose of the study: to reveal the necessary competencies of a modern teacher of the Higher School, necessary for the preparation of competitive specialists and managers. The article uses historical, logical and comparative research methods, systems approach and modelling method. The author substantiates the factors, influencing the transformation of the modern ecosystem and the modern student, the characteristic features of students at universities, identifies the, and indicates on need to change the mission of the higher school and the teacher. A list of key competencies of a lecturer and seminarian of the higher school, which helps him to prepare the competitive graduate, was highlighted.
Digital technologies: drivers of economic growth during COVID-19 pandemic
Authors: Serikov S. G.
Published: May 2022

The article examines the drivers of economic growth in a difficult epidemiological situation. The problems of economic activity during this period are identified. It was revealed that cloud technologies, digital platforms and blockchain technologies can act as the main drivers of the growth of the pandemic economy. A comparative analysis of the level of development of digitalization processes in the Russian economy in comparison with other countries is presented. The main problems and threats to the development of the digitalization process in Russia are noted. It has been established that the digital economy in Russia is in its infancy – the main direction is the acquisition of equipment (computer and communication technology). Despite the measures taken by the state to launch digitalization processes in the domestic economy, Russian companies lag far behind foreign competitors in terms of the degree of implementation and use of digital technologies in their activities. In the current situation, it is necessary to continue state support for such areas as import substitution, the export of domestic digital products, and the creation of equal operating conditions for all IT companies.
Following the ESG principles as sustainable development factor of foreign economic activity of the Vladimir region
Authors: Baranova A. F. , Kulakova O. S. , Ignatov D. D.
Published: May 2022

The work is devoted to establishing a correlation between the effectiveness of foreign economic activity of the Russian region and the adherence of economic entities to the ESG principle. The international community recognizes that the most important goal today is the socio-economic development of territories while minimizing the negative anthropogenic impact on the environment. Today it is important that all types of economic activity are aimed at improving the quality of life. Therefore, there is an active development and popularization of business activity concepts aimed not only at achieving financial indicators, but also creating conditions for social justice, environmental safety and cleanliness of doing business. The paper analyses the importance of following the principles of sustainable development to maximize the effectiveness of foreign economic activity of Russian regions and attract foreign investment to certain territories of the country.
Improving the efficiency, safety and manageability of oil transportation processes
Authors: Shvechihin D. V. , Sheikina M. A.
Published: May 2022

The article is devoted to the analysis of the main opportunities for the digital transformation of an oil company, which are based on improving the efficiency, safety and controllability of production processes, obtaining additional economic benefits, and achieving leadership in terms of innovation. For the development and success of an oil and gas company, it is necessary to introduce measures to increase its economic growth, sustainability and competitiveness in the market. A key component of a business transformation strategy is digital transformation. The authors analysed the challenges for the digital transformation of the oil and gas industry: changing the importance of oil as an energy source, changing the market, business conditions, technology development, and environmental and social factors. The strategic directions for the development of digital transformation are considered and the main aspects of its roadmap are presented. The key success factors for the digital transformation of an oil company are identified.
Key Factors in the Development of the ASEAN Logistics System
Authors: Dang Quang Binh , Anikin B. A.
Published: May 2022

Due to growing economy, investment, abundant labour force and tourism industry, the Association of Southeast Asian Nations (ASEAN) is becoming increasingly attractive to other parts of the world. ASEAN has a vast logistics system that contributes to the overall potential for development. The article examines key factors in the development of the ASEAN logistics system, the trends in the formation and ways of the effective development of logistics processes in the modern era of digitalization are revealed. The scientific novelty of the work lies in the fact that during a pandemic, digital technologies can contribute to the successful development of business in the logistics industry for ASEAN. In this regard, there is a need to focus the ASEAN region on automating the management of logistics processes, introducing and improving IT products, as well as on the needs of consumers and improving the quality of services provided.
Life quality in Russia: a brief overview
Authors: Ermilina D. A.
Published: May 2022

The life quality is a fundamental characteristic by which it is possible to assess the level of socio-economic development of the territory for which it is assessed. The main purpose of the study is to assess the key socio-economic parameters that affect the life quality in Russia. Methods of system analysis, classification and generalization were used in the study. The analysis of the main macroeconomic indicators affecting the quality of life in our country, such as gross domestic product, inflation rate, unemployment rate, the volume of credit resources issued, household consumption expenditures, is carried out. The main trends of their changes are revealed. The article convincingly shows that the life quality is formed under the influence of external and internal factors, which together reflect the living standard state of the population (material well-being, consumption of goods). The values of the vast majority of key factors affecting the life quality of Russian population have negative dynamics. To change the situation, it is necessary to develop a comprehensive system of measures, where the key role is assigned to state regulation, which actively responds to the transformations taking place in the socio-economic environment.
Revealing Carbon Capture Chemistry with 17-Oxygen NMR Spectroscopy
Authors: Berge Astrid , Pugh Suzi , Short Marion , Kaur Chanjot , Lu Ziheng , Lee Jung-Hoon , Pickard Chris , Sayari Abdelhamid , Forse Alexander
Published: May 2022

Carbon dioxide capture is an essential greenhouse mitigation technology to achieve netzero emissions. A key hurdle to the design of improved carbon capture materials is the lack of adequate tools to characterise how CO2 adsorbs. Solid-state nuclear magnetic resonance (NMR) spectroscopy is emerging as a promising probe of CO2 capture, but it remains challenging to distinguish different adsorption products. Here we perform a comprehensive computational investigation of 22 amine-functionalised metal-organic frameworks and discover that 17O NMR is a powerful probe of CO2 capture chemistry that provides excellent differentiation of ammonium carbamate and carbamic acid species. The computational findings are supported by 17O NMR experiments on a series of CO2-loaded frameworks that clearly identify ammonium carbamate chain formation and provide new evidence for a mixed carbamic acid – ammonium carbamate adsorption mode. The fine sensitivity of 17O NMR to local chemistry also shows that hydrogen bonding schemes proposed in previous ammonium carbamate chain structures may be inaccurate and new structures are proposed. We further discover a new mixed CO2 adsorption mechanism and show that carbamic acid formation is more prevalent in this materials class than previously believed. Finally, we show that our methods are readily applicable to other adsorbents, and find support for ammonium carbamate formation in amine-grafted silicas. Overall our work paves the way for new investigations of carbon capture chemistry that can enable the design of improved materials.
Pushing and pulling on OH- and H3O+ with electric fields across water’s surface
Authors: Ray Kamal , Limaye Aditya , Ng Ka Chon , Saha Ankur , Shin Sucheol , Gaigeot Marie-Pierre , Pezzotti Simone , Willard Adam , Allen Heather
Published: May 2022

We use second harmonic generation (SHG) spectroscopy, molecular dynamics simulation, and theoretical modeling to study the response of the neat liquid water-air interface to changes in the potential of an external electrode positioned above the liquid out of contact. We observe a parabolic dependence of second harmonic intensity on applied potential. This dependence is reminiscent of bulk-phase electric field induced second harmonic (EFISH) but more complicated because it combines the second-order response of the topmost water layer and the potential dependent response of the interfacial electrical double-layer. Based on the literature values for these contributions, we derive a physical interpretation of our measurements that reveals new insight into the response of the neat water interface to external electric fields. Specifically, we find that the net dipolar orientation of water molecules within the double-layer is primarily responsive to the internal fields generated by the excess surface concentrations of OH- and H3O+ that arise to screen the external potential. Notably, this interpretation implies that the orientational response of water dipoles at the interface can actually oppose the direction of the external field, a subtle effect that is not captured by traditional models.
Ligand enabled disproportionation of 1,2-diphenylhydrazine at a P(V)-center
Authors: Karnbrock Simon B. H. , Golz Christopher , Mata Ricardo A. , Alcarazo Manuel
Published: May 2022

We present herein the synthesis of a nearly square pyramidal chlorophosphorane supported by the tetradentate bis(amidophenolate) ligand, N,N’-bis(3,5-di-tert-butyl-2-phenoxy)-1,2-phenylenediamide. After chloride abstraction the resulting phosphonium cation efficiently catalyzes the disproportionation of 1,2-diphenylhydrazine to aniline and azobenzene. Mechanistic studies, spectroscopic analyses and theoretical calculations suggest that it is the combination of high electrophilicity at the cationic P(V)-center, which originates from the geometry constraints imposed by the rigid pincer ligand, and the ability of the o-amidophenolate moieties to act as electron reservoir what leverages this unprecedented reactivity mode for P(V)-centres. This study illustrates the promising role of cooperativity between redox-active ligands and phosphorus for the design of organocatalysts able to promote redox processes.
Enhancing the capacity of supercapacitive swing adsorption CO2 capture by tuning charging protocols
Authors: Binford Trevor , Mapstone Grace , Temprano Israel , Forse Alexander
Published: May 2022

Supercapacitive swing adsorption (SSA) is a recently discovered electrochemically driven CO2 capture technology that promises significant efficiency improvements over traditional methods. A limitation of this approach is the relatively low CO2 adsorption capacity, and the underlying molecular mechanisms of SSA remain poorly understood, hindering optimization. Here we present a new device architecture for simultaneous electrochemical and gas adsorption measurements, and use it to investigate the effects of charging protocols on SSA performance. We show that altering the voltage applied to charge the SSA device can significantly improve performance. Charging the gas-exposed electrode positively rather than negatively increases CO2 adsorption capacity and causes CO2 desorption rather than adsorption with charging. We also show that switching the voltage between positive and negative values further increases CO2 capacity. Previously proposed mechanisms of the SSA effect fail to explain these phenomena, so we present a new mechanism based on movement of CO2-derived species into and out of electrode micropores. Overall, this work advances our knowledge of electrochemical CO2 adsorption by supercapacitors, potentially leading to devices with increased uptake capacity and efficiency.
Dynamic community detection decouples hierarchical timescale behavior of complex chemical systems
Authors: Zarayeneh Neda , Kumar Nitesh , Kalyanaraman Ananth , Clark Aurora
Published: May 2022

Although community or cluster identification is becoming a standard tool within the simulation community, traditional algorithms are challenging to adapt to time dependent data. Here we introduce temporal community identification using the delta-screening algorithm which has the flexibility to account for varying community compositions, merging and splitting behaviors within dynamically evolving chemical networks. When applied to a complex chemical system whose varying chemical environments cause multiple timescale behavior, delta-screening is able to resolve the hierarchical timescales of temporal communities. This computationally efficient algorithm is easily adapted to a wide range of dynamic chemical systems; flexibility in implementation allows the user to increase or decrease the resolution of temporal features by controlling parameters associated with community composition and fluctuations therein.
Biocatalytic Carbene Transfer Using Diazirines
Authors: Porter Nicholas , Danelius Emma , Gonen Tamir , Arnold Frances
Published: May 2022

Biocatalytic carbene transfer from diazo compounds is a versatile strategy in asymmetric synthesis. However, the limited pool of stable diazo compounds constrains the variety of accessible products. To overcome this restriction, we have engineered variants of Aeropyrum pernix protoglobin (ApePgb) that use diazirines as carbene precursors. While the enhanced stability of diazir- ines relative to their diazo isomers enables access to a diverse array of carbenes, they have previously resisted catalytic activation. Our engineered ApePgb variants represent the first example of catalysts for selective carbene transfer from these species at room temperature. The structure of an ApePgb variant, determined by microcrystal electron diffraction (MicroED), reveals that evolution has enhanced access to the heme active site to facilitate this new-to-nature catalysis. Using readily prepared aryl diazirines as model substrates, we demonstrate the application of these highly-stable carbene precursors in biocatalytic cyclopropanation, N–H insertion, and Si–H insertion reactions.
Solvent Organization and Electrostatics Tuned by Solute Electronic Structure: Amide vs. Non-Amide Carbonyls
Authors: Fried Steven , Zheng Chu , Mao Yuezhi , Markland Thomas , Boxer Steven
Published: May 2022

The ability to exploit carbonyl groups to measure electric fields in enzymes and other complex reactive environments using the vibrational Stark effect has inspired growing interest in how these fields can be measured, tuned, and ultimately designed. Previous studies have concentrated on the role of the solvent in tuning the fields exerted on the solute. Here, we explore instead the role of the solute electronic structure in modifying the local solvent organization and electric field exerted on the solute. By measuring the infrared absorption spectra of amide-containing molecules, as prototypical peptides, and contrasting them with non-amide carbonyls in a wide range of solvents, we show that these solutes experience notable differences in their frequency shifts in polar solvents. Using vibrational Stark spectroscopy and molecular dynamics simulations, we demonstrate that while some of these differences can be rationalized using the distinct intrinsic Stark tuning rates of the solutes, the larger frequency shifts for amides and dimethylurea primarily result from the larger solvent electric fields experienced by their carbonyl groups. These larger fields arise due to their stronger p-π conjugation, which results in larger C=O bond dipole moments that further induce substantial solvent organization. Using electronic structure calculations, we decompose the electric fields into contributions from solvent molecules that are in the first solvation shell and those from the bulk and show that both of these contributions are significant and become larger with enhanced conjugation in solutes. These results show that structural modifications of a solute can be used to tune both the solvent organization and electrostatic environment, indicating the importance of a solute-centric paradigm in modulating and designing the electrostatic environment in condensed-phase chemical processes.
Synthesis and styrene copolymerization of novel alkyl ring-substituted octyl phenylcyanoacrylates
Authors: Wasilewski Martin S. , Al Abosy Jude , Albareedi Ahmad , Albrecht Alexis , Angus Cheyenne L. , Brahmbhatt Shrustiben B. , Buenaventura Kyra J. , Debruzzi Kristi A. , Farah Asha E. , Rocus Sara M. , Schjerven William S. , Kharas Gregory B
Published: May 2022

Novel alkyl ring-substituted octyl phenylcyanoacrylates, RPhCH=C(CN)CO2CH2(CH2)6CH3 (where R is H, 2-methyl, 3-methyl, 4-methyl, 4-ethyl, 4-propyl, 4-i-propyl, 4-butyl, 4-t-butyl, 4-i-butyl) were prepared and copolymerized with styrene. The acrylates were synthesized by the piperidine catalyzed Knoevenagel condensation of ring-substituted benzaldehydes and octyl cyanoacetate, and characterized by CHN analysis, IR, 1H and 13C NMR. All the acrylates were copolymerized with styrene in solution with radical initiation (ABCN) at 70C. The compositions of the copolymers were calculated from nitrogen analysis.
FLEXIBLE TOPOLOGY: A NEW METHOD FOR DYNAMIC DRUG DESIGN
Authors: Donyapour Nazanin , Roussey Nicole , Bose Samik , Dickson Alex
Published: May 2022

Ligand-induced conformational changes form the underpinnings of most essential biomolecular processes, however they are often neglected in screening and design applications, due to the high computational cost. We propose a method called “Flexible Topology”, where a ligand is comprised of a set of shapeshifting “ghost” atoms, whose atomic identities and connectivity can dynamically change over the course of a simulation. Ghost atoms are guided toward their target positions using a translation-, rotation-, and index-invariant restraint potential. When implemented with a large set possible targets, this can simulate trajectories in a coupled chemical-conformational space that allows solutions to molecular design problems to simply emerge over the course of a trajectory. It also provides a mechanism for observing ligand-induced conformational change, by allowing for the surrounding environment and the ghost atoms to respond to each other during the design process. This builds on a substantial history of alchemy in the field of molecular dynamics simulation, including the Lambda dynamics method developed by Brooks and coworkers [X. Kong and C.L. Brooks III, J. Chem. Phys. 105, 2414 (1996)], but takes it to an extreme by associating a set of four dynamical variables with each shapeshifting atom that control not only its presence but its atomic identity. Here we outline the theoretical details of this method, its implementation using the OpenMM simulation package, and some preliminary studies of ghost particle assembly simulations. We show that while Flexible Topology is able to consistently assemble molecules up to 50 atoms in size, modifications are needed before it can reliably predict bound poses in heterogeneous environments.
Decoding Regioselective Reaction Mechanism of the Gentisic Acid Catalyzed by Gentisate 1,2-Dioxygenase Enzyme
Authors: Nath Rounak , Manna Rabindranath , Paul Ankan
Published: May 2022

Gentisate 1,2-dioxygenase (GDO), a ring-fission non-heme dioxygenase enzyme, displays a unique regioselective reaction of gentisic acid (GTQ) in the presence of molecular oxygen. GTQ is an important intermediate in the aerobic biodegradation pathways of recalcitrant polyaromatic hydrocarbons (PAHs) pollutants. Classical molecular dynamics simulations of wild-type GDO and its mutated variants (Asp174Glu and Asp174Ala) explored the presence of three active water molecules at the active site which plays pivotal roles in facilitating the oxidative cleavage of an aromatic C-C bond of the GTQ substrate. Three distinct reaction mechanisms using the QM/MM calculations decoded for the regioselective reaction of the GTQ catalyzed by GDO enzyme. The formation of the main product as a maleylpyruvate along with pathway A, which is the most favourable one. The first step for the conversion to an alkyl peroxo intermediate is a rate-determining step with an associated barrier of 21.4 kcal/mol at the uB3LYP-D3/def2-TZVP/OPLS level of theory on the quintet spin surface. Our study illustrates the crucial role of active water molecules in the stabilization of the O2 molecule, the O-O, and C-C bond cleavage steps and additionally uncovered the important anchor role of the Asp174 in the enzymatic cycle. Essentially, our findings paved a new route in the mechanism of degradation processes of PAHs pollutants by dioxygenase enzymes, and provide molecular insights to design iron-containing biomimetic catalysts.
Gradient bundle analysis of ketosteroid isomerase
Authors: Wilson Timothy , Morgenstern Amanda , Alexandrova Anastassia , Eberhart Mark
Published: May 2022

Bond bundle analysis is used to investigate enzymatic catalysis in the KSI active site. We identify the unique bonding regions in each system and calculate the precise redistribution of electron density that accompanies either enhancement or inhibition of KSI catalytic activity. In two examples—using direct inspection of bond bundle regional properties, and using correlations between those properties and reaction barrier height—we arrive at similar conclusions, that cat- alytic enhancement results from promoting electron density redistribution between bonds within the KSI-docked substrate molecule in a way that closely resembles our mechanistic understanding of the forward catalyzed reaction. This catalyzing charge redistribution is prevalent in KSI systems catalyzed via electric fields or via amino acid mutation, and are thus suggestive of a significant catalytic role. Bond bundle analysis also generates a wealth of statistically useful bond properties, making it a strong candidate for machine learning approaches to computer- aided artificial enzyme design, and a promising tool for the discovery of relationships between the structure of the electron charge density and enzymatic catalytic activity.
Synthesis of Highly Congested Tertiary Alcohols via the [3,3] Radical Deconstruction of Breslow Intermediates
Authors: Machín Rivera Roger , Burton Nikolas , Call Luke , Tomat Marshall , Lindsay Vincent
Published: May 2022

Pericyclic processes such as [3,3]-sigmatropic rearrangements leading to the rapid generation of molecular complexity constitute highly valuable tools in organic synthesis. Herein, we report the formation of particularly hindered tertiary alcohols via rearrangement of Breslow intermediates formed in situ from readily available N-allyl thiazolium salts and benzaldehyde derivatives. Experimental mechanistic studies performed suggest that the reaction proceeds via a close radical pair which recombine in a regio- and diastereoselective manner, formally leading to [3,3]-rearranged products.
Connecting material properties and redox flow cell cycling performance through analytical zero-dimensional models
Authors: Neyhouse Bertrand , Lee Jonathan , Brushett Fikile
Published: May 2022

Improvements in redox flow battery (RFB) performance and durability can be achieved through the development of new active materials, electrolytes, and membranes. While a rich design space exists for emerging materials, complex tradeoffs challenge the articulation of unambiguous target criteria, as the relationships between component selection and cycling performance are multifaceted. Here, we derive analytical solutions for zero-dimensional galvanostatic cell cycling models, enabling direct connections between material / electrolyte properties, cell operating conditions, and resulting performance metrics (e.g., energy efficiency, capacity fade). To demonstrate the utility of this modeling framework, we highlight several representative considerations for RFB design, including upper bound estimation, active species decay, and membrane / separator conductivity-selectivity tradeoffs. We also discuss modalities for extending this analytical framework to incorporate kinetic losses, distributed ohmic losses, and multiple spatial domains. Importantly, because the model is derived analytically, hundreds of cycles can be simulated in seconds, potentially facilitating detailed parametric sweeps, system optimization, and parameter estimation from cycling experiments. More broadly, this approach provides a means for assessing the impact of cell components that simultaneously influence multiple performance-defining processes, aiding in the elucidation of key descriptors and the identification of favorable materials combinations for specific applications.
Rapid GC-MS as a Screening Tool for Forensic Fire Debris Analysis
Authors: Capistran Briana , Sisco Edward
Published: May 2022

Techniques developed for the screening of forensic samples can be useful for increasing sample throughput and decreasing backlog in forensic laboratories. One such technique, rapid gas chromatography mass spectrometry (GC-MS), allows for fast sample screening (≈1 min) and has gained interest in recent years for forensic applications. This work focuses on the development of methods for ignitable liquid analysis using rapid GC-MS. A sampling protocol and temperature program were developed for the analysis of these volatile samples. Using the optimized method for analysis, the limits of detection for compounds commonly found in ignitable liquids ranged from 0.012 mg/mL to 0.018 mg/mL. Once the analysis method was developed, neat ignitable liquids (i.e., gasoline and diesel fuel) were analyzed, and major components in each liquid were identified. The identification of gasoline and diesel fuel in the presence of substrate interferences was then assessed through the analysis of simulated fire debris samples. Three different substrates were spiked with each ignitable liquid, burned, and analyzed. Major compounds in both liquids were identified using the total ion chromatograms, relevant extracted ion profiles, and deconvolution methods.
Improving education in electrochemistry via a modeling approach and focusing on green chemistry applications
Authors: Ciriminna Rosaria , Ghahremani Mina , Varmaghani Fahimeh , Karimi Babak , Pagliaro Mario
Published: May 2022

Chemistry is understood and practiced by research chemists by models and visualization. Electrochemistry is no exception. This study shows how a modeling approach focusing on green chemistry applications holds great potential in improving electrochemistry education. Green electrosynthesis, for instance, is ideally suited to understand electrochemical phenomena and to foster the student’s interest and learning in this cross-disciplinary field of chemical knowledge, reinforcing also laboratory education.
A REVIEW ON SENTIMENT ANALYSIS
Authors: Kumawat Pramod , Dey Ratul
Published: May 2022

Sentiment analysis is an technique which identifies text from different kind of image and dataset. It also characterized the data from Twitter, Facebook and YouTube. Sentiment analysis is a part of machine learning technique which find the trends of data and predict future trend. This paper shows different kind of machine learning and lexicon analysis methodology in the current trend and also we compare different kind of algorithms in sentiment analysis in different dataset.
CLASS IMBALANCE PROBLEM IN DATA SCIENCE: REVIEW
Authors: Yogi Abhishek , Dey Ratul
Published: May 2022

In last few years there are many changes and evolution has been done on the classification of data. Application area of technology increases then the size of data also increases. Classification of data becomes difficult because of imbalance nature and unbounded size of data. Class imbalance problem becomes the greatest issue in the data mining. Imbalance problem occurs where one of the two classes having more sample than the other classes. The most of the algorithms are focusing on the classification of major sample while ignoring minority sample. The minority samples are those samples that rarely occur but are very important. There are different methods available for the classification of imbalance data set which is divided into three categories i.e. the algorithmic approach, feature selection approach and the data processing approach. These approaches have their own advantages and disadvantages. In this paper a systematic study of each process is defined which gives the right direction for research in class imbalance problem.