Basic Conformations Research Articles

The Interaction between Chondroitin Sulfate and Dermatan Sulfate Tetrasaccharides and Pleiotrophin.

Pleiotrophin (PTN) is a neurotrophic factor that participates in the development of the embryonic central nervous system (CNS) and neural stem cell regulation by means of an interaction with sulfated glycosaminoglycans (GAGs). Chondroitin sulfate (CS) is the natural ligand in the CNS. We have previously studied the complexes between the tetrasaccharides used here and MK (Midkine) by ligand-observed NMR techniques. The present work describes the interactions between a tetrasaccharide library of synthetic models of CS-types and mimetics thereof with PTN using the same NMR transient techniques. We have concluded that: (1) global ligand structures do not change upon binding, (2) the introduction of lipophilic substituents in the structure of the ligand improves the strength of binding, (3) binding is weaker than for MK, (4) STD-NMR results are compatible with multiple binding modes, and (5) the replacement of GlcA for IdoA is not relevant for binding. Then we can conclude that the binding of CS derivatives to PTN and MK are similar and compatible with multiple binding modes of the same basic conformation.

Chemistry of 2,14-Dithiacalix[4]arene: Searching for the Missing Fifth Conformer.

Contrary to theoretical predictions, direct alkylation of 2,14-dithiacalix[4]arene provides only four out of five basic conformers (atropisomers). To prepare the missing 1,2 (C)-alternate conformer, the indirect alkylation strategy was applied using 1,3-dichloro-1,1,3,3-tetraisopropyldisiloxane as a protective agent. As proved by the combination of NMR and X-ray crystallography, the position of the disiloxane bridge on the macrocycle is not fixed and can be changed under basic conditions, representing thus so far unknown rearrangement of the siloxane moiety. The subsequent dialkylation/deprotection and dialkylation enabled the synthesis of the last missing conformer. As demonstrated by several examples, the mixed-bridge macrocycle (with both CH2 and S bridging units) enables preparation of unusual conformers or substitution patterns, which are difficult to obtain, if at all, in classical calixarene chemistry. This feature makes 2,14-dithiacalix[4]arene a very promising candidate for the role of molecular scaffold or platform in various supramolecular applications.

Вплив тривалого застосування систем основного обробітку та удобрення на структуру ґрунту

The results of researches of influence of the protracted application of the different systems of basic till of soil and fertilizer are presented on basic conformities to law and parameters of changes of the structural state that took place in an arable layer. It is educed that on a background a organic-mineral fertilizer for 20 years place improvement of structuralness of arable layer on 4,5-6,0 % by the greatest index for the moldboard systems. On a background a mineral fertilizer for this period the decline of amount of structuralness aggregates is marked from 0,1 % and chisel systems to 0,6 % and moldboard. In middle for 20 replacement of ploughing nonmoldboard tills on a background a organic-mineral fertilizer resulted in the decline of structuralness of arable layer on 2,0–8,0 %. On a background a mineral fertilizer a tendency was kept, though with some more subzero values, and to the organic-mineral background declines folded 0,1–3,7 %. Amount agronomical valuable aggregates in soil depended on the amount of debrises, evenness of their placing on an arable layer and from intensity of loosening. From time of sowing to the harvest the structuralness of soil got better with the greatest positive effect in sowing of mustard white, some more subzero, - to soy and most subzero - wheat winter-annual and at permanent advantage of background of organic-mineral fertilizer above mineral.

Default memory network and working memory network in exercise addicts

Objective To explore the characteristics of the default memory network (DMN) and working memory network (WMN) at resting state brain functional network of exercise addiction people. Methods Twenty-nine sports addicts and 26 non-sports addicts matched by sex, age, average education level and sports dependence were screened by the exercise addiction index (EAI). Resting status brain scanning was performed with 3.0T magnetic resonance scanner.Sparse approximation coefficients independent component analysis (SACICA) model was used to analyze the independent components of brain networks. Results Compared with the DMN template, four features were extracted, including basic conformity , less frontal lobe , more frontal lobe and less occipitoparietal lobe . Compared with the parameters of basic conformity , the proportion of exercise addiction group (33.3%, 9/27) was higher than that of control group (18.2%, 4/22). In the other three parameters, the proportion of exercise addiction group (37.0%, 10/27; 3.7%, 1/27; 22.2%, 6/27) was lower than those of control group (45.5%, 10/22; 22.7%, 5/22; 27.3%, 6/22). But Chi-square test showed that there was no significant difference between the two groups(all P>0.05). Compared with the WMN template, six features were extracted, including basic conformity , more frontal and parietal lobes , more parietal lobes , more frontal lobes , less frontal lobes and less parietal lobes . The percentages of the first three features in exercise addiction group (22.2%, 6/27; 7.4%, 2/27; 7.4%, 2/27) were less than those in the control group (45.5%, 10/22; 22.7%, 5/22; 9.1%, 2/22), while the percentages of the last three features in the exercise addiction group (7.4%, 2/27; 37.0%, 10/27; 14.8%, 4/27) were higher than those in the control group (4.5%, 1/22; 13.6%, 3/22; 0, 0). Chi-square test showed that there was no significant difference in all features between the two groups was statistically(P>0.05). Conclusion No significant characteristic changes are found in DMN and WMN networks of exercise addiction population. Key words: Sports addiction; Resting state; Sparse approximation coefficients independent component analysis; Default memory network; Working memory network

Quantitative Photo-crosslinking Mass Spectrometry Revealing Protein Structure Response to Environmental Changes.

Protein structures respond to changes in their chemical and physical environment. However, studying such conformational changes is notoriously difficult, as many structural biology techniques are also affected by these parameters. Here, the use of photo-crosslinking, coupled with quantitative crosslinking mass spectrometry (QCLMS), offers an opportunity, since the reactivity of photo-crosslinkers is unaffected by changes in environmental parameters. In this study, we introduce a workflow combining photo-crosslinking using sulfosuccinimidyl 4,4′-azipentanoate (sulfo-SDA) with our recently developed data-independent acquisition (DIA)-QCLMS. This novel photo-DIA-QCLMS approach is then used to quantify pH-dependent conformational changes in human serum albumin (HSA) and cytochrome C by monitoring crosslink abundances as a function of pH. Both proteins show pH-dependent conformational changes resulting in acidic and alkaline transitions. 93% and 95% of unique residue pairs (URP) were quantifiable across triplicates for HSA and cytochrome C, respectively. Abundance changes of URPs and hence conformational changes of both proteins were visualized using hierarchical clustering. For HSA we distinguished the N–F and the N–B form from the native conformation. In addition, we observed for cytochrome C acidic and basic conformations. In conclusion, our photo-DIA-QCLMS approach distinguished pH-dependent conformers of both proteins.

LIFE INSURANCE UNDER REFORMING THE PENSION INSURANCE SYSTEM

The purpose of the paper is to generate practical recommendations on the prospects of life insurance development under reforming the pension insurance system in Ukraine. Methodology. In the article, a considerable attention is paid to international experience, the implementation of which is relevant for Ukraine today. In determining the place of life insurance in European pension systems, the experience of Spain and the United Kingdom is considered, which is sufficiently indicative for Ukraine and can serve as a model for reforming the national pension system. Methodological basis of the article are methods of scientific cognition, which enable to expose basic conformities to the law of development of the pension systems in this countries and place of life insurance in them. Such methods are in particular used as: analysis and synthesis – during the study of reforming pension systems, their detailed analysis and definition of their peculiarities; scientific abstraction – with the purpose of forming of theoretical generalizations and conclusions; also, the method of scientific synthesis, forecasting method, econometric modelling for forecasting the development of life insurance in Ukraine up to 2020. Results. The pension insurance system of Ukraine is at the stage of reformation by introducing compulsory accumulation of pension funds and the development of voluntary non-state pension insurance. The main financial intermediaries providing voluntary pension accumulation services in Ukraine are: banks – through the possibility of saving on retirement deposits, insurance companies – through life insurance products, and non-state pension funds (NPFs) – through the voluntary participation of citizens in such funds. The article discusses the key differences in the activity of the given subjects in the system and also determines the place of life insurance itself in the system of pension insurance in Ukraine. Practical significance. Having considered the key macroeconomic indicators of Ukraine’s economic development, the article predicts the volume of investments into NPFs and insurance premiums for life insurance companies using econometric methods; the benefits and prospects of life insurance are determined. Practical recommendations on the prospects of life insurance development under reforming the pension insurance system in Ukraine are formulated. Value/originality. The modelling of the development of the non-state level of the pension system of Ukraine allowed determining the dynamics of growth of contributions to life insurance companies and contributions to the NPFs in 2017-2020 and drawing a conclusion on the positive prospects for the development of the life insurance market in Ukraine and its special role in the successful reformation of Ukraine’s pension system.

Evaluation of Web content accessibility in an Israeli institution of higher education

Nowadays, the Web constitutes an integral part of higher education and offers an unprecedented level of access to information and services. The increasing number of students with disabilities in higher education emphasizes the need of universities and colleges to make the necessary adjustments to ensure their Web content accessibility. Despite the development of technical standards and accessibility legislation, studies around the world have consistently shown that Web content accessibility remains a concern in higher education. Mandatory Web accessibility in Israel is at an early stage. The scope of the legal requirements applicable to higher education is not entirely resolved. The aim of this research is to explore the current implementation of Web accessibility in the Israeli higher education context, during a period of evolving legal changes in this regard. An automated evaluation tool was used to measure the adherence of the sample Web pages to the technical standards. Results show that all examined Web pages presented accessibility barriers and were non-compliant with the most basic conformance level. “Contrast” and “missing alternative text” errors were the most frequent problems identified in the evaluation. The library’s Web pages exhibit relatively better level of accessibility compared to the other examined Web pages of the university. The research highlights the need for clear and enforceable legislation to encourage academic Web accessibility. Additionally, technical training and awareness raising could be key elements in improving accessibility.

Еволюція застосування системи обробітку ґрунту за методом Т. С. Мальцева в УРСР у 1954-1955 роках

Basic conformities to law and tendencies of application of the system of till of soil have been set after the method of Terentij Semen Maltsev in Ukraine in 1954–1955. The role of the collective farm experimental stations has been reflected in the productive experiments execution and research establishments in realization of the ground and agrochemical researches in relation to efficiency of application of the system of till of soil without dumps in sowing of different agricultural cultures of Steppe, Forest-Steppe and Polesye of Ukraine.

AnkPlex: algorithmic structure for refinement of near-native ankyrin-protein docking

BackgroundComputational analysis of protein-protein interaction provided the crucial information to increase the binding affinity without a change in basic conformation. Several docking programs were used to predict the near-native poses of the protein-protein complex in 10 top-rankings. The universal criteria for discriminating the near-native pose are not available since there are several classes of recognition protein. Currently, the explicit criteria for identifying the near-native pose of ankyrin-protein complexes (APKs) have not been reported yet.ResultsIn this study, we established an ensemble computational model for discriminating the near-native docking pose of APKs named “AnkPlex”. A dataset of APKs was generated from seven X-ray APKs, which consisted of 3 internal domains, using the reliable docking tool ZDOCK. The dataset was composed of 669 and 44,334 near-native and non-near-native poses, respectively, and it was used to generate eleven informative features. Subsequently, a re-scoring rank was generated by AnkPlex using a combination of a decision tree algorithm and logistic regression. AnkPlex achieved superior efficiency with ≥1 near-native complexes in the 10 top-rankings for nine X-ray complexes compared to ZDOCK, which only obtained six X-ray complexes. In addition, feature analysis demonstrated that the van der Waals feature was the dominant near-native pose out of the potential ankyrin-protein docking poses.ConclusionThe AnkPlex model achieved a success at predicting near-native docking poses and led to the discovery of informative characteristics that could further improve our understanding of the ankyrin-protein complex. Our computational study could be useful for predicting the near-native poses of binding proteins and desired targets, especially for ankyrin-protein complexes. The AnkPlex web server is freely accessible at http://ankplex.ams.cmu.ac.th.

Regio-/stereoselective formation of monosulfoxides from thiacalix[4]arenes in all possible conformations

The partial S-oxidation of all four basic conformations of thiacalix[4]arene was carried out using NaBO3·4H2O as the oxidizing agent. It was found that despite the possible formation of many regio- and stereoisomers, the reactions leading to mono- or disulfoxides were highly regio- and stereoselective depending on the starting conformation. Our results clearly show that the sulfur atoms possessing syn-orientation of the appended phenolic units are remarkably more reactive than the sulfur atoms with anti-oriented aromatic subunits. Moreover, the most easily formed syn-oriented equatorial configuration is highly preferred over the corresponding axial arrangement which was never observed. As demonstrated by the resolution of racemic products, partial S-oxidation represents a very interesting tool to access novel inherently chiral building blocks based on thiacalix[4]arenes.

SPECIFICATIONS OF THE SOURCES OF SECURING INSURANCE COMPANY’S FINANCIAL STABILITY

The purpose is to generalize the methodological concepts of domestic researchers in sources of insurance companies' financial stability provision. The need in developing and deepening both theory and practice upon the issues of improving financial stability of the Ukrainian insurance companies facilitated the following tasks: analysis of methodical approaches of native researchers concerning division of financial stability sources; highlighting the most important sources of securing financial stability for insurance companies; feasibility of the role and essence of each factor securing financial stability for insurance companies. Methodology. The study is based on the theoretical analysis of scientific works and practical activity of enterprises. Methodological basis of the article are methods of scientific cognition, which enable to expose basic conformities to the law of development of the insurance companies, priority ways to ensure their financial sustainability. Such methods are in particular used: analysis and synthesis – during research of financial stability of the insurance companies; systematizations – for revealing factors of maintenance of financial stability of insurers, their detailed analysis and definition of their interrelation; scientific abstraction – with the purpose of forming theoretical generalizations and conclusions. Results. The insurance sector plays an important role in the provision of critical financial services. But insurers are exposed to a number of risks and can become distressed or fail. The article examines the essence and importance of insurance company’s financial stability as an important factor in the development and functioning of the insurance market. The economic essence of the general theoretical issues about the financial stability of insurance companies is reviewed and analysed. The main features of insurance companies and the factors that affect their financial stability are investigated. Value. The economic and social importance of insurance is such that the intervention of public authorities, in the form of prudential supervision, is generally accepted to be necessary. Not only do insurers provide protection against future events that may result in a loss, they also channel household savings into the financial markets and into the real economy. The intervention of public authorities has tended to focus on introducing the measures that seek to guarantee the solvency of undertakings or minimise the disruption and loss caused by insolvency. Therefore, the study of the legislative regulation of the factors of providing financial stability of insurance companies is of strategic importance towards creating a stable insurance market in Ukraine.

IMPLEMENTATION OF MODERN FOREIGN APPROACHES TO UKRAINIAN PENSION SYSTEM REFORMING

A study of the experience of Western European countries in implementing structural reforms of the pension insurance system and the implementation of such experience in Ukraine. The main task of the pension system of any country in the world is to ensure the corresponding stable level of incomes of pensioners and at the same time maintain their financial stability. The increase in the proportion of pensioners increases the burden on pension systems, and mainly measures taken by countries are aimed at reducing pension costs and parametric reforms. Methodology. This article investigates the prerequisites and consequences of reforming the pension systems of the Member States of the Organization for International Cooperation and Development. Considered measures to ensure the financial stability of pension systems of the countries concerned, increased the social and stimulating role of pension insurance in the society. The methodological basis of the article is methods of scientific cognition, which enable to expose basic conformities to the law of development of the pension systems, priority ways to ensure their financial sustainability. Such methods are in particular used: analysis and synthesis – during research of financial indicators of pension systems; systematization – for revealing methods for reforming pension systems, their detailed analysis and the definition of their features; scientific abstraction – with the purpose of forming theoretical generalizations and conclusions. Results. The article investigates the trends of reforming pension insurance systems in some countries. It is established that today the main characteristics of pension reforms in foreign countries are increasing the retirement age, improving the solidary component of the pension system, reducing the role of state pension insurance. Some countries raise their contribution rates; the conditions for early retirement are becoming tougher. Almost nobody decided to reduce the nominal size of pensions, but some countries introduce automatic adjustment of their size depending on the growth of life expectancy, incomes and expenditures of the pension system. In recent years, a number of countries, despite budgetary problems, have introduced tax incentives or co-financing voluntary savings to increase the proportion of citizens taking part in them. Others used nonfinancial incentives to expand coverage. The article outlines the main directions of reforming the pension system in Ukraine, namely, the expansion of the tax base for the working population, the introduction of the second pillar of the pension system, and the popularization of individual funded programs. Practical significance. The necessity of changes in the pension system of Ukraine on the basis of the effects of the reform of pension systems of the leading countries of the world. This made the cardinal changes in the systems in the countries of the world: the transition from financing pensions from current receipts to the system of individual accounts and savings, raising the retirement age, reviewing tariffs and requirements for risk management in pension funds, etc. Importance/ originality: conducted a sample of reforms in pension insurance of foreign countries and offered the possibility of implementing only the part that can be adapted and applied in the light of the individual characteristics of the Ukrainian state.

Evolution of the use of instruments of till of soil in home agriculture

Basic conformities to law and tendencies of forming of theoretical and practical bases of the use of instruments of till of soil are certain in agriculture. The looks of leading scientists-agriculturists are reflected in relation to effective till of soil in sowing of different agricultural cultures.

An exceptional 5:4 enantiomeric structure.

The only crystals that could be grown from racemic solutions of the PF6(-) salt of the resolvable cation [Ru(2,9-dimethyl-1,10-phenanthroline)2(dipyrido[3,2-d:2',3'-f]quinoxaline)](2+) have translational symmetry only (space group P1), contain nine independent sets of ions, and include numerous independent solvent molecules (11 acetone, one diethyl ether and possibly several water molecules). Layers of hydrophobic cations alternate with layers containing most of the anions and solvent molecules. All nine cations have the same basic conformation, which is distorted by the presence of the methyl substituents on the two 1,10-phenanthroline ligands. Four pairs of enantiomeric cations within a layer are related by approximate inversion centers; the ninth cation, which shows no sign of disorder, makes the layer chiral. Within the cation layers stripes parallel to [110] of six cations alternate with stripes of three; the local symmetry and the cation orientations are different in the two stripes. These stripes are reflected in the organization of the anion/solvent layer. The ca 80:20 inversion twinning found indicates that enantiomeric preference is transmitted less perfectly across the anion/solvent layer than within the cation layer. The structure is exceptional in having nine independent formula units and an unbalanced set (ratio 4:5) of resolvable enantiomers. The difficulty in growing crystals of this material is consistent with its structural complexity.

MECHANISM OF FINANCIAL SAFETY FORMATION OF ENTERPRISES OF AGROINDUSTRIAL COMPLEX

The purpose of work is research of essence of mechanism of forming of financial safety of subjects of agro-industrial complex as to the economic category. Basic financial interests of business entity and financial tasks are certain for their achievement. Considered organization of forming of financial safety of enterprises of agroindustrial complex and offered the measures of realization of the effective system of defence of subjects. The system of financial safety is directed foremost on providing of the own functioning, however, it is necessary to underline that at the same time it is a component part, both at the level of structural subdivisions of subject and at the level of industry, region, state. Financial safety of agrarian sphere is the important constituent of economic security of the state, which acquires an important value for further development of country. Methodology. Methodological basis of the article are methods of scientific cognition, which enable to expose basic conformities to law of development of the probed phenomena and processes, their key problems and priority ways of decision. Such methods are in particular used: analysis and synthesis – during research of constituents of economic security of agricultural enterprises, in particular such as financial safety, and to their aggregate on the whole; systematizations – for dismemberment and more rich in content understanding of essence of the separate probed phenomena and processes; to scientific abstraction – with the purpose of forming of theoretical generalizations and conclusions. A research result is opening of mechanism of financial safety forming of agro-industrial enterprises on the modern stage of socio-economic development of Ukraine. The offered model of strategic prognostication has for an object development of strategy of forming of financial safety of enterprises of agro-industrial complex. Such strategy must avouch for financial prospects enterprises, to answer their aims. As a result, depending on the worked out strategy of financial safety, it is possible to draw basic directions of guaranteeing his financial safety activity of enterprises of agro-industrial complex. Organizational-economic principles of forming of mechanism of financial safety of agricultural enterprises must be built on the basis of realization of its expressly certain strategy. It, in same queue, must go out from present of their production potential. This strategy is the basic internal reference-point of forming of financial safety of agricultural enterprise that sets the parameters of all her development. Practical implications. On financial safety of enterprises of agro-industrial complex testifies the conducted analysis of scientific researches, that without regard to the wide list of existing in economic literature researches on the mechanism of forming of enterprises’ financial safety, among scientific circles until now there is not a general idea. It requires forming of new knowledge’s in relation to forming of mechanism of enterprise financial safety, where not only the certain state of subject but also dynamic constituent of development must come forward as a priority lever, what is considered in this article. Value/originality. Creation of valuable mechanism of forming of financial safety of agro-industrial enterprises foresees formulation of criteria and principles of providing of financial safety of every enterprise, determinations of priority national interests in a financial sphere, realization of the permanent watching of factors, which cause a threat financial safety, and also acceptance of measures in relation to their warning and overcoming. The formed mechanism of financial safety of the agricultural formations is pre-condition of prevention of financial threats and negative financial phenomena in production activity of the agricultural formations, defence of their financial losses, and in future stabilizing of activity of the agricultural formations and development in the conditions of competition economic position.

Uwagi o kodeksowej regulacji dokonywania za pracodawcę czynności z zakresu prawa pracy

The aim of this text is to determine whether the evolution of Polish Labour code regulation of acting on behalf of an employer has reached the level which satisfies the requirements defined in a theory and practice of labour law. The author accepts the decision of the Polish legislator who abolished in 1996 the principle of one-man management in labour law relations. The above-mentioned principle did not correspond with market economy conditions which put an end to a domination of state in employment relations. The binding article 3¹ of Labour code has established a short general formula. The wording of this regulation makes possible a basic conformity with the rules laid down in Polish Civil Code which define an ability of a an employer to act in civil law relations. Labour code regulation preserves a necessary level of autonomy of the notion of acting on behalf of an employer. The above-mentioned autonomy is connected with the wide scope of employer’s acts in labour law relations and a particular notion of an employer treated as a organizational unit which need not be a legal person. On the other hand there are a few serious problems which arise from the present regulation and should be dissolved in a future Polish Labour code. In the author’s opinion there are some open questions such as the legal position of a person established by an employer to act on behalf of him and the relation between representation of an employer in labour law relations and in proceedings at law.

Transient Kinetics Measured with Force Steps Discriminate between Double Stranded DNA Elongation and Melting and Define the Reaction Energetics

Double stranded DNA pulled to ∼65 pN undergoes an overstretching transition from the basic conformation (B-form) to a 1.7 times longer conformation that represents a fundamental stage in the structural transitions during DNA recombination, replication and repair. By using a dual laser optical tweezers with a fast force feedback (2 ms rise time), we recorded the length transient following force steps imposed on the λ-phage DNA with different degrees of melting and at different temperatures (10-25°C). The rate-force relations obtained from the lengthening transient under our rapid force clamp following 2-35 pN force pull to the overstretching force shows that the whole 70% extension is a two state reaction from the B-form to an S-form that precedes and is independent of melting. The shortening transient following 20-35 pN force drop from the overstretching force is made by stepwise shortenings and pauses due to S-B transitions and reannealing of the melted segments. The temperature dependence of the lengthening transient shows that the entropic contribution to the reaction at room temperature is only 1/3 of the entropy change expected from thermal melting. The structural parameters that describe the distances from the B and the S state to the transition state, do not depend on temperature. Accordingly the total elongation of a single two-state unit, and therefore q, the index of cooperativity (22bp) of the reaction, do not depend on temperature, suggesting that it arises from structural factors, such as the nucleic acid sequence. Supported by IIT-SEED (Genova) and Ente Cassa di Risparmio di Firenze.

Transient kinetics measured with force steps discriminate between double-stranded DNA elongation and melting and define the reaction energetics

Under a tension of ∼65 pN, double-stranded DNA undergoes an overstretching transition from its basic (B-form) conformation to a 1.7 times longer conformation whose nature is only recently starting to be understood. Here we provide a structural and thermodynamic characterization of the transition by recording the length transient following force steps imposed on the λ-phage DNA with different melting degrees and temperatures (10–25°C). The shortening transient following a 20–35 pN force drop from the overstretching force shows a sequence of fast shortenings of double-stranded extended (S-form) segments and pauses owing to reannealing of melted segments. The lengthening transients following a 2–35 pN stretch to the overstretching force show the kinetics of a two-state reaction and indicate that the whole 70% extension is a B-S transition that precedes and is independent of melting. The temperature dependence of the lengthening transient shows that the entropic contribution to the B-S transition is one-third of the entropy change of thermal melting, reinforcing the evidence for a double-stranded S-form that maintains a significant fraction of the interstrand bonds. The cooperativity of the unitary elongation (22 bp) is independent of temperature, suggesting that structural factors, such as the nucleic acid sequence, control the transition.

Taking away of liquid phase is in centrifugal vehicle

Basic conformities to law, influencing on taking away of liquid phase in centrifugal masstransfer vehicle, are exposed. Influence of operating parameters - closenesses of irrigation, gas speed, number of turns of rotor on the size of the total taking away of liquid phase is experimentally studied

Unprecedented Conformational Variability in Main Group Inorganic Chemistry: the Tetraazidoarsenite and -Antimonite Salts A+[M(N3)4]− (A = NMe4, PPh4, (Ph3P)2N; M = As, Sb), Five Similar Salts, Five Different Anion Structures

A unique example for conformational variability in inorganic main group chemistry has been discovered. The arrangement of the azido ligands in the pseudotrigonal bipyramidal [As(N(3))(4)](-) and [Sb(N(3))(4)](-) anions theoretically can give rise to seven different conformers which have identical MN(4) skeletons but different azido ligand arrangements and very similar energies. We have now synthesized and structurally characterized five of these conformers by subtle variations in the nature of the counterion. Whereas conformational variability is common in organic chemistry, it is rare in inorganic main group chemistry and is usually limited to two. To our best knowledge, the experimental observation of five distinct single conformers for the same type of anion is unprecedented. Theoretical calculations at the M06-2X/cc-pwCVTZ-PP level for all seven possible basic conformers show that (1) the energy differences between the five experimentally observed conformers are about 1 kcal/mol or less, and (2) the free monomeric anions are the energetically favored species in the gas phase and also for [As(N(3))(4)](-) in the solid state, whereas for [Sb(N(3))(4)](-) associated anions are energetically favored in the solid state and possibly in solutions. Raman spectroscopy shows that in the azide antisymmetric stretching region, the solid-state spectra are distinct for the different conformers, and permits their identification. The spectra of solutions are solvent dependent and differ from those of the solids indicating the presence of rapidly exchanging equilibria of different conformers. The only compound for which a solid with a single well-ordered conformer could not be isolated was [N(CH(3))(4)][As(N(3))(4)] which formed a viscous, room-temperature ionic liquid. Its Raman spectrum was identical to that of its CH(3)CN solution indicating the presence of an equilibrium of multiple conformers.