Репозитарій

UDC 611.132.2–055.1–071.3

The size of the coronary arteries is an essential parameter in assessing coronary anatomy, which depends on age and anthropometric indicators. However, there is limited data on the correlation between biometric indicators and coronary arteries’ size among Ukrainian residents. The purpose of the study is to evaluate the size of the coronary ostia and study their correlation with age, height, weight, body mass index, and body surface area in men with and without coronary artery disease using coronary angiography. The study group consisted of 98 patients: 64 patients with and 34 patients without lesions of the coronary arteries (treated as healthy or within the norm). In patients with no coronary artery disease, the ostium of the left coronary artery is higher than that of the right coronary artery: 5.94±1.41 mm versus 5.09±1.36 mm, p=0.013. In men with coronary artery disease, the average parameters of the height of the left coronary artery (5.45±1.10 mm) are significantly more extensive than the height of the right coronary artery 4.91±1.05 mm (p=0.005). In the healthy group, a direct relationship of medium strength between the data of the height of the right coronary artery ostium and height was proven (r=+0.34, p=0.049), as well as an inverse relationship of medium strength between the value of the height of the right coronary artery ostium and age (r= -0.35, p=0.041). No correlation of age-anthropometric parameters with the value of the height of the ostium of the left coronary artery has been found. Relationships between the left coronary artery index and age, weight, and height have been established in men with coronary artery disease.

Abstract. The article examines the problem of ensuring the psychological stability of students during the war.  The level of psychological stability of the student in connection with his visit was analyzed.  A study was conducted using a survey of students of several universities in Ukraine.  The developed questionnaire made it possible to outline that most students feel anxiety and fear.  The influence of the psycho-emotional state during the war on the educational performance of students was determined.  There are ways to reduce the feeling of anxiety, tension, fear and directions of adjustment  of  the  psychological  climate  in  the  context  of  resistance  to  stressful  situations.  The object of this study is the psychological stability of students during university studies and studies under martial law.  The subject of the study is the peculiarities of the formation of psychological stability in students and the means of its formation. The purpose of the study is to determine the psychological  conditions  for  the  formation  of  students'  psychological  stability.    Factors  of stressogenicity and psychological stability of students in war conditions were studied. The  research  revealed  the  psychological  essence  of  stress  resistance  and  psychological resilience. On the basis of the survey, the mental state of students of higher education institutions during  the  war  was  analyzed.  The  methods  of  increasing  the  level  of  psychological  stability  of students  while  studying  during  the  war  are  considered.  Practical  recommendations  on  the formation  of  stress  resistance  and  psychological  stability  of  students  of  higher  education institutions during the war are presented.

Abstract

   Development of an effective and safe antioxidant compound is still challenging in the last few decades. There has been an increasing interest in the role of reactive oxygen species (ROS) in food, drugs, and even living system. Free radical formation is associated with the normal natural metabolism of aerobic cells. They are inevitably exposed to reactive oxygen species formed as oxygen metabolites. Oxidative stress which is largely characterized by reactive oxygen and nitrogen species is implicated in the development of a number of chronic and degenerative diseases such as atherosclerosis, cancer, cirrhosis, diabetes, wound healing and aging. Free radicals are highly reactive and therefore can attack membrane lipids, generating carbon radicals and peroxy radicals, which cause lipid peroxidation. Therefore, scientists in various disciplines have become more interested in naturally-occurring antioxidants as well as in related synthetic derivatives that could provide active components which prevent or reduce the impact of oxidative stress. Іn order to study the effect of various substituents in the molecules on the nature of thepharmacological activity of thiazolo[4,5-b]pyridin-2-ones, a series of new compounds were synthesized based on the previously obtained 5,7-dimethyl-3Hthiazolo[4,5-b]pyridin-2-one. The high electrophilicity of the N3 position in 5,7-dimethyl-3H-thiazolo[4,5-b]pyridin- 2-one allows to use of its functionalization as a convenient method for obtaining various N3-substituted derivatives to expand the range of thiazolo[4,5-b]pyridines. In particular, an NH center with a mobile hydrogen atom at the N3 position in 5,7-dimethyl-3H-thiazolo[4,5-b]pyridin-2-one allows conducting a synthesis based on 3-substituted derivatives. This conversion was carried out through the stage of obtaining potassium salt. Several chloroacetamides were tested as alkylating agents, which allowed to obtain the corresponding 2-(5,7-dimethyl-2-oxo-thiazolo[4,5-b]pyridin-3-yl)-N-aryl-acetamides (1–6). Methods of quantitative elemental analysis, mass spectrometry, and 1H NMR spectroscopy were used to confirm the structure and individuality of the synthesized substances. Interpretation of the spectra revealed that the signals for protons of all structural units were observed in their characteristic ranges.

Mounting research has been performed in the recent decades focusing on natural and low-molecular-weight synthetic antioxidants discovering as key molecules that control oxidative damage and its pathway to disease.

Oxidative stress is a phenomenon resulting from the imbalance between oxidation-reduction processes, in particular, the formation and accumulation reactive oxygen species (ROS) and reactive nitrogen species (RNS) in cells and tissues, and the ability of the antioxidant defence system of the organism to eliminate these by-products. Oxidative stress develops under the influence of external or internal factors and leads to oxidative modification of biomolecules, in particular lipids, proteins and DNA [6]. One- and two-electron oxidation-reduction reactions, as an integral part of aerobic metabolism, often lead to free radicals’ in vivo formation. Molecular oxygen reduction processes include the stepwise single electron reduction of O₂ results in such ROS generation as superoxide anion radical (O₂^•-), hydrogen peroxide (H₂O₂) and hydroxyl radical (HO^•). H₂O₂ is produced as a result of two-electron O₂ reduction. Reactive nitrogen species include mainly nitric oxide (NO^•), nitrogen dioxide (NO₂^•) and peroxynitrite (ONOO⁻), as well as non-radicals such as nitrous acid HNO₂ and N₂O₄ (dinitrogen tetroxide).

At lower concentrations ROS/RNS have beneficial effects and indulged in different physiological processes such as redox regulation, mitogenic responses, cellular signaling pathways, and an immune function while at a higher level, these reactive species generate nitrosative and oxidative stress.

In modern research the two main types of antioxidants are distinguished: (1) the primary antioxidants, or free radical scavengers, which are able to break the chain reaction; (2) the secondary, or preventive, antioxidants, for which the action mechanisms may include the deactivation of metals, inhibition of lipid hydroperoxides by interrupting the production of undesirable volatiles, the regeneration of primary antioxidants, and the elimination of singlet oxygen. The methods of the antioxidant capacity determining are commonly classified into two main groups, based on the reaction mechanisms involved in free radicals’ reduction process: (a) hydrogen atom transfer (HAT) reactions; and (b) transfer reactions of a single electron (SET).