The Oxidative Balance Orchestrates the Main Keystones of the Functional Activity of Cardiomyocytes

This review is aimed at providing an overview of the key hallmarks of cardiomyocytes in physiological and pathological conditions. The main feature of cardiac tissue is the force generation through contraction. This process requires a conspicuous energy demand and therefore an active metabolism. The cardiac tissue is rich of mitochondria, the powerhouses in cells. These organelles, producing ATP, are also the main sources of ROS whose altered handling can cause their accumulation and therefore triggers detrimental effects on mitochondria themselves and other cell components thus leading to apoptosis and cardiac diseases. This review highlights the metabolic aspects of cardiomyocytes and wanders through the main systems of these cells: (a) the unique structural organization (such as different protein complexes represented by contractile, regulatory, and structural proteins); (b) the homeostasis of intracellular Ca2+ that represents a crucial ion for cardiac functions and E-C coupling; and (c) the balance of Zn2+, an ion with a crucial impact on the cardiovascular system. Although each system seems to be independent and finely controlled, the contractile proteins, intracellular Ca2+ homeostasis, and intracellular Zn2+ signals are strongly linked to each other by the intracellular ROS management in a fascinating way to form a “functional tetrad” which ensures the proper functioning of the myocardium. Nevertheless, if ROS balance is not properly handled, one or more of these components could be altered resulting in deleterious effects leading to an unbalance of this “tetrad” and promoting cardiovascular diseases. In conclusion, this “functional tetrad” is proposed as a complex network that communicates continuously in the cardiomyocytes and can drive the switch from physiological to pathological conditions in the heart.

Semi-paracrystallinity in semi-conducting polymers

Precise determination of structural organization of semi-conducting polymers is of paramount importance for the further development of these materials in organic electronic technologies. Yet, prior characterization of some of the...

All Structures Great and Small: Nanoscale Modulations in Nematic Liquid Crystals

The nature of the nanoscale structural organization in modulated nematic phases formed by molecules having a nonlinear molecular architecture is a central issue in contemporary liquid crystal research. Nevertheless, the elucidation of the molecular organization is incomplete and poorly understood. One attempt to explain nanoscale phenomena merely “shrinks down” established macroscopic continuum elasticity modeling. That explanation initially (and mistakenly) identified the low temperature nematic phase (NX), first observed in symmetric mesogenic dimers of the CB-n-CB series with an odd number of methylene spacers (n), as a twist–bend nematic (NTB). We show that the NX is unrelated to any of the elastic deformations (bend, splay, twist) stipulated by the continuum elasticity theory of nematics. Results from molecular theory and computer simulations are used to illuminate the local symmetry and physical origins of the nanoscale modulations in the NX phase, a spontaneously chiral and locally polar nematic. We emphasize and contrast the differences between the NX and theoretically conceivable nematics exhibiting spontaneous modulations of the elastic modes by presenting a coherent formulation of one-dimensionally modulated nematics based on the Frank–Oseen elasticity theory. The conditions for the appearance of nematic phases presenting true elastic modulations of the twist–bend, splay–bend, etc., combinations are discussed and shown to clearly exclude identifications with the nanoscale-modulated nematics observed experimentally, e.g., the NX phase. The latter modulation derives from packing constraints associated with nonlinear molecules—a chiral, locally-polar structural organization indicative of a new type of nematic phase.

Genre Originality of Novel by M. Vargas Llosa “Green House”

The genre nature of the novel “Green House” by the Peruvian writer Mario Vargas Llosa is analyzed in the article. Special attention is paid to three approaches to the definition of the genre: “Green House” as a total novel, as a chivalric novel and as an Indianist novel. Definitions of each genre under consideration are given. The relevance of the study is due to the fact that the prevailing approaches to defining the genre of the “Green House” in contemporary Latin American studies is analyzed in the paper. In the course of the work seven stable characteristics of the total novel are distinguished: a radically realistic author’s intention, a clear structural organization of the text, compositional and semantic unity, the consciousness of the infinity of language, the comprehensiveness of the novel, nonlinearity of narration, and the use of dialogue as a structure-forming device. The question of the presence in the novel “Green House” of signs of a chivalric romance is considered. The results of a comparative analysis of the “Green House” and the Catalan novel “Tyrant White” are presented. A comparison of the structure of the “Green House” and the generalized structure of the Indianist novel is given, the key features of this genre are analyzed. It is concluded that in the case of the “Green House” it is impossible to come to genre definiteness. The authors dwell on the fact that “Green House” is a work of fiction that combines elements of different genres, without any other restrictions in interpretations, except for those directly rejected by the text.

Structural organization criminal law regulations of chapter 22 of the criminal code of the Russian Federation from the standpoint of legislative textology

The article attempts to identify and provide solutions to a number of problems related to the design features of the criminal law prescriptions of Chapter 22 of the criminal code of the Russian Federation. The methodological basis of this scientific publication is the dialectical method of cognition, taken in unity with instrumental research methods. As a result of the study, the author came to the conclusion that in the text of Chapter 22 of the criminal code of the Russian Federation, it is possible to distinguish structural units, which include the headings of articles, descriptive and thematic elements of criminal law regulations, their compositional and graphic features and notes to articles.

Teratogenic effect of alcohol on the myocardium of laboratory animals at the stages of prenatal ontogenesis (literature review)

Background. To date, close attention is paid to the problems of formation and development of the myocardium in general and in particular its structural components. This phenomenon is associated with an increase in cardiovascular malformations in both adults and infants. These defects can be caused by genetic factors, as well as various teratogenic substances. One such substance is alcohol. Despite the risks, many women still drink alcohol during pregnancy. The main problem is that almost half of pregnancies are unplanned, so a woman may continue to consume alcohol for several weeks before learning about her condition. Especially in young women, fertilization can occur in a state of intoxication. In addition, under the influence of ethanol, cardiac function may be impaired in the absence of structural abnormalities. Chronic alcohol intoxication causes changes in the myocardium at all levels of its structural organization. First of all, teratogenic changes caused by the action of ethanol affect the development of cardiomyocytes in the process of embryogenesis, which contributes to the underdevelopment of the structure or function of heart cells. Although the effect of maternal alcohol consumption on the fetus has been studied for decades, there are still conflicting conclusions about the severity of myocardial morphological changes depending on the time, frequency and duration of alcohol consumption. Objective: to conduct a retrospective analysis of literature sources devoted to the study of adverse effects on the fetus caused by alcohol. Methods. The paper conducted a retrospective analysis of literature references and formed an understanding of the changes in the structure of the myocardium caused by teratogenic effects of alcohol. Results and conclusion. Analysis of literature sources showed a high level of adverse effects observed in offspring born to alcoholic mothers. Detrimental effects of alcohol cause changes in the myocardium at all levels of structural organization, including its ultrastructure. It was studied that prenatal exposure to ethanol induces significant changes in relative heart weight, left ventricular wall thickness and cardiomyocyte size. Exposure to high concentrations of alcohol in experimental animals during gestation can lead to congenital heart defects, such as atrial, ventricular, and septal defects. The main manifestation of the prenatal effect of alcohol after birth is the fetal alcohol syndrome, which combines various degrees of deviation in the development of the child.

Nano-Organization at the Synapse: Segregation of Distinct Forms of Neurotransmission

Synapses maintain synchronous, asynchronous, and spontaneous modes of neurotransmission through distinct molecular and biochemical pathways. Traditionally a single synapse was assumed to have a homogeneous organization of molecular components both at the active zone and post-synaptically. However, recent advancements in experimental tools and the further elucidation of the physiological significance of distinct forms of release have challenged this notion. In comparison to rapid evoked release, the physiological significance of both spontaneous and asynchronous neurotransmission has only recently been considered in parallel with synaptic structural organization. Active zone nanostructure aligns with postsynaptic nanostructure creating a precise trans-synaptic alignment of release sites and receptors shaping synaptic efficacy, determining neurotransmission reliability, and tuning plasticity. This review will discuss how studies delineating synaptic nanostructure create a picture of a molecularly heterogeneous active zone tuned to distinct forms of release that may dictate diverse synaptic functional outputs.