Steerochemistry of heterocycles. - V. Stereochemical peculiarities of 1,3-dioxanes and 1,3-dithianes

The stereochemical peculiarities of substituted 1,3-dioxanes and 1,3-dithianes are discussed. The high probability of the existence of flexible conformations in these series, the considerable energy preference of the 5-C-axial position in the chair conformation of 1,3-dioxanes and 1,3-dithianes, and the definite preference of the 2-C-axial position in the chair conformation of 1,3-dithianes as compared with the axial conformations of the cyclohexane type are noted. The PMR spectra of stereoisomeric 2,5-dimethyl-5-isopropyl-1,3-dioxanes, 2-methy-l5-isopropyl-1,3-dithianes, and 2,2,5-trimethyl-1,3-dithiane are described, and their configurations and preferred conformations are proved. The results of a study of the epimerization of stereoisomers of substituted 1,3-dioxanes and 1,3-dithianes are examined, and the conformational energies of individual substituents in the 5-position of these cyclic systems are calculated on the basis of this examination. © 1973 Consultants Bureau, a division of Plenum Publishing Corporation

RESULTS OF A 20-YEAR FOLLOW-UP OF CHILDREN WITH GROWTH HORMONE DEFICIENCY IN THE REPUBLIC OF TATARSTAN

One of the most important parameters of health in children is growth. Stunted growth leads to the development of inferiority complex in patients and often hampers social self-realization. Over the past two decades, the Republic of Tatarstan has been actively diagnosing and treating growth hormone deficiency in children with short stature. Children with isolated growth hormone deficiency receive monotherapy with recombinant growth hormone. Early treatment of children with growth hormone deficiency led to an improvement in anthropometric parameters and, consequently, psychological and social adaptation of this group of patients

Historical Aspect of the Concepts «Revenues» and «Expenses»

Актуальность представленного исследования определяется возникновением вопросов о происхождении таких понятий как доходы и расходы. Цель работы состоит в изучении истор ического аспекта возникновения таких понятий как «доходы» и «расходы». Методы исследования. Использование исторической базы для получения нужной информации, так же использование конкретных данных для прослеживания тенденции их возникновения. Результаты. Изучены исторические аспекты появления данных понятий.The relevance of the presented research is determined by the questions about the origin of such concepts as income and expenses. The aim of this work is to study the historical aspect of the emergence of such concepts as "revenue" and "expenses". Research methods. The use of historical databases to obtain the desired information, as well the use of specific data to track trends in their occurrence. Results. Studied the historical aspects of the emergence of these concepts

Insurance contributions: essence, the history of, regulation

Актуальность представленного исследования определяется возникновением вопросов о том, что же такое страховые взносы, куда они платятся, зачем они нужны и в каком размере они должны уплачиваться. Цель работы: изучение нормативной базы по выплате и начислению страховых взносов, а также прослеживание тенденции изменения данных взносов. Методы исследования. Использование нормативной базы для получения нужной информации, так же использование конкретных данных для прослеживания проблемы в данной теме. Результаты. Исследован теоретический аспект. В котором указаны нормативные документы по данному исследованию, а также применен на практическом примере. В данном исследовании приведены два примера, которые наглядно иллюстрируют ситуацию, показывают проблему.The relevance of the presented research is determined by the questions about what insurance contributions where they are paid, why they are needed and in what amount they should be paid. The main aim of the study: the regulatory framework for the payment and accrual of insurance premiums, as well as tracking trends in the data contributions. Methods. The use of a standard base to obtain the desired information, as well the use of specific data to track problems in this thread. Results. Studied the theoretical aspect. Which outlines the regulatory documents for this study and applied on a practical example. In this study, are two examples that clearly illustrate the situation, show the problem

Steerochemistry of heterocycles. - V. Stereochemical peculiarities of 1,3-dioxanes and 1,3-dithianes

The stereochemical peculiarities of substituted 1,3-dioxanes and 1,3-dithianes are discussed. The high probability of the existence of flexible conformations in these series, the considerable energy preference of the 5-C-axial position in the chair conformation of 1,3-dioxanes and 1,3-dithianes, and the definite preference of the 2-C-axial position in the chair conformation of 1,3-dithianes as compared with the axial conformations of the cyclohexane type are noted. The PMR spectra of stereoisomeric 2,5-dimethyl-5-isopropyl-1,3-dioxanes, 2-methy-l5-isopropyl-1,3-dithianes, and 2,2,5-trimethyl-1,3-dithiane are described, and their configurations and preferred conformations are proved. The results of a study of the epimerization of stereoisomers of substituted 1,3-dioxanes and 1,3-dithianes are examined, and the conformational energies of individual substituents in the 5-position of these cyclic systems are calculated on the basis of this examination. © 1973 Consultants Bureau, a division of Plenum Publishing Corporation

Steerochemistry of heterocycles. - V. Stereochemical peculiarities of 1,3-dioxanes and 1,3-dithianes

The stereochemical peculiarities of substituted 1,3-dioxanes and 1,3-dithianes are discussed. The high probability of the existence of flexible conformations in these series, the considerable energy preference of the 5-C-axial position in the chair conformation of 1,3-dioxanes and 1,3-dithianes, and the definite preference of the 2-C-axial position in the chair conformation of 1,3-dithianes as compared with the axial conformations of the cyclohexane type are noted. The PMR spectra of stereoisomeric 2,5-dimethyl-5-isopropyl-1,3-dioxanes, 2-methy-l5-isopropyl-1,3-dithianes, and 2,2,5-trimethyl-1,3-dithiane are described, and their configurations and preferred conformations are proved. The results of a study of the epimerization of stereoisomers of substituted 1,3-dioxanes and 1,3-dithianes are examined, and the conformational energies of individual substituents in the 5-position of these cyclic systems are calculated on the basis of this examination. © 1973 Consultants Bureau, a division of Plenum Publishing Corporation

Steerochemistry of heterocycles. - V. Stereochemical peculiarities of 1,3-dioxanes and 1,3-dithianes

The stereochemical peculiarities of substituted 1,3-dioxanes and 1,3-dithianes are discussed. The high probability of the existence of flexible conformations in these series, the considerable energy preference of the 5-C-axial position in the chair conformation of 1,3-dioxanes and 1,3-dithianes, and the definite preference of the 2-C-axial position in the chair conformation of 1,3-dithianes as compared with the axial conformations of the cyclohexane type are noted. The PMR spectra of stereoisomeric 2,5-dimethyl-5-isopropyl-1,3-dioxanes, 2-methy-l5-isopropyl-1,3-dithianes, and 2,2,5-trimethyl-1,3-dithiane are described, and their configurations and preferred conformations are proved. The results of a study of the epimerization of stereoisomers of substituted 1,3-dioxanes and 1,3-dithianes are examined, and the conformational energies of individual substituents in the 5-position of these cyclic systems are calculated on the basis of this examination. © 1973 Consultants Bureau, a division of Plenum Publishing Corporation