[Cardiohemodynamic Changes and Cardiac Arrhythmias After Coronavirus Infection].

Aim      To study changes in cardiohemodynamic alterations of the myocardium and heart rhythm disorders at 3 and 6 months following the coronavirus infection.Material and methods   EchoCG, ECG Holter monitoring, and Doppler ultrasonography of hepatolienal blood vessels were performed for 77 patients (mean age, 35.9 years) at 3 and 6 months after coronavirus infection. The patients were divided into the following groups: group 1, with injury of the upper respiratory tract; group 2, with bilateral pneumonia (CТ1, 2), and group 3, with severe pneumonia (CТ3, 4). Statistical analysis was performed with a SPSS Statistics Version 25.0 software package.Results At 6 months after the disease onset, the patients noted an improvement of their general condition. In patients with moderate pneumonia, early peak diastolic velocity (p=0.09), right ventricular isovolumic diastolic time (р=0.09), and pulmonary artery systolic pressure (р=0.005) where decreased, while tricuspid annular peak systolic velocity was, in contrast, increased (р=0.042). Both segmental systolic velocity of the LV mid-inferior segment (р=0.006) and the mitral annular Em / Am ratio were decreased. In patients with severe disease at 6 months, right atrial indexed volume was reduced (р=0.036), tricuspid annular Em / Am was decreased (р=0.046), portal and splenic vein flow velocities were decreased, and inferior vena cava diameter was reduced. Late diastolic transmitral flow velocity was increased (р=0.027), and LV basal inferolateral segmental systolic velocity was decreased (р=0.046). In all groups, the number of patients with heart rhythm disorders was decreased, and parasympathetic autonomic influences prevailed.Conclusion      At 6 months after coronavirus infection, practically all patients noted improvement of their general condition; incidence rate of arrhythmia and cases of pericardial effusion were decreased; and autonomic nervous system activity recovered. In patients with moderate and severe disease, morpho-functional parameters of the right heart and the hepatolienal blood flow were normalized, however, occult disorders of LV diastolic function remained, and LV segmental systolic velocity was reduced.

[The dynamics of indicators of selenium, glutathione and anti-oxidant defense of blood in patients with anemic cardiomyopathy against the background of treatment with preparations of iron and selenium].

The study was carried out on samplings of 46 patients with asiderotic anemia of severe degree and complicated by cardiomyopathy and 16 healthy persons. The content of selenium was analyzed using I.I. Nazarenko technique of detection of mass concentration GOST 19413-89. The content of glutathione in blood was detected using the technique based on capacity of acid-soluble thiol aggregations at interaction with 5,5-dithio-bis(2-nitrobenzene) acid to form a colored compound--thio-2-nitrobenzene acid. The principle of technique of measurement of activity of glutathione peroxidase of blood ervthrocvtes is in capacity of peroxide hydrogen to form a resistant colored complex with molybdenum salts. The technique of detection of activity of glutathione peroxidase is based on its capacity to catalyze reaction of interaction of reduced glutathione with tretbutyl hydro peroxide and on capacity of glutathione reductase to catalyze NADFN-dependent reduction of oxidated glutathione. The principle of technique of detection of activity of superoxiddismutase is based on capacity of enzyme to suppress reaction of reduction of nitro blue tetrazolium with superoxide anion-radical generated in vitro in the system xanthine-xanthineoxidase. The study established decreasing of content of selenium in blood of patients with anemic cardiomyopathy up to 1.8 times as compared with control group. The content of total glutathione in blood of patients was decreased up to 17.7% at the expense of decreasing of level of reduced glutathione up to 18.5%. The study established decreasing of activity of catalase in erythrocytes up to 1.3 times, glutathione peroxidase up to 2.5 times, glutathione reductase up to 2.1 times and superoxiddismutase up to 1.5 times as compared with control group. After the preparations of iron and selenium ware applied to patients with anemic cardiomyopathy the increase of level of selenium in blood up to 80.4% was established. The level of total glutathione increased up to 54.5% at the expense of increase of content of reduced glutathione up to 59.5%. The activity of blood erythrocytes in patients against the background of treatment increased up to 9.1%, the activity of glutathione peroxidase, glutathione reductase and superoxiddismutase of blood erythrocytes increased up to 3, 2.1 and 2 times respectively.

Optical detection of CO and CO2 temperature dependent desorption from carbon nanotube clusters.

The development of new materials relies on high precision methods to quantify adsorption/desorption of gases from surfaces. One commonly used approach is temperature programmed desorption spectroscopy. While this approach is very accurate, it requires complex instrumentation, and it is limited to performing experiments under high vacuum, thus restricting experimental scope. An alternative approach is to integrate the surface of interest directly onto a detector face, creating an active substrate. One surface that has applications in numerous areas is the carbon nanotube (CNT). As such, an active substrate that integrates a CNT surface on a sensor and is able to perform measurements in ambient environments will have significant impact. In the present work, we have developed an active substrate that combines an optical sensor with a CNT cluster substrate. The optical sensor is able to accurately probe the temperature dependent desorption of carbon monoxide and carbon dioxide gases from the CNT cluster surface. This active substrate will enable a wide range of temperature dependent desorption measurements to be performed from a scientifically interesting material system.

Search for production of invisible final states in single-photon decays of Υ(1S).

We search for single-photon decays of the Υ(1S) resonance, Υ â†’ γ + invisible, where the invisible state is either a particle of definite mass, such as a light Higgs boson A°, or a pair of dark matter particles, χχ. Both A° and χ are assumed to have zero spin. We tag Υ(1S) decays with a dipion transition Υ(2S) → π⁺π⁻Υ(1S) and look for events with a single energetic photon and significant missing energy. We find no evidence for such processes in the mass range m(A°) ≤ 9.2 GeV and m(χ) ≤ 4.5 GeV in the sample of 98 × 106 Υ(2S) decays collected with the BABAR detector and set stringent limits on new physics models that contain light dark matter states.

[Peculiarities of systolic and diastolic function of left and right ventricles in elderly and geriatric patients with stable effort class II-III angina during formation of chronic heart failure].

In order to reveal peculiarities of function of cardiac ventricles in functional class (FC) II-III chronic heart failure (CHF) Doppler echocardiography (DE) and myocardial tissue Doppler echocardiography (TDE) were carried out in 108 middle aged, elderly and old patients. Patients with signs of FCIII CHF had pronounced impairment of global contractile function of left and right ventricles (LV and RV) with RV ejection fraction (EF) higher than LV EF. These patients had lower parameters of central hemodynamics, high parameters of pulmonary hypertension, increased thickness of RV free wall, greater percentage of irreversible LV and RV myocardium in response to deep breath, more pronounced derangements of RV and LV diastolic filling. In patients with FC II of CHF and moderate RV dysfunction its pump function is determined by degree of impairment of systolic function, diastolic filling, while in patients with FC III of CHF and pronounced dysfunction of RV myocardium its pump function is to a lesser degree determined by ventricular contractile function, but becomes dependent on diastolic filling of RV and the state of LV.

[The role of dopamine and serotonin in modulating the defensive behavior of the edible snail]. / Rol' dofamina i serotonina v moduliatsii oboronitel'nogo povedeniia vinogradnoi ulitki.

Dopamine application in concentration of 10(-5)-10(-6) M into saline around the snail CNS leads to decrease of excitability of LPa7 neurone which is presynaptic in relation to defensive behaviour command neurones, and to decrease of amplitude of monosynaptic excitatory postsynaptic potential (EPSP) in the command neurones elicited by intracellular stimulation of LPa7 neurone. Besides, the dopamine causes a decrease of summated EPSP amplitude in the studied neurones in response to intestinal nerve stimulation (70% in average), a change of rest potential towards hyperpolarization for 6-8 mV, a reduction of the command neurones input resistance (20% in average). The described influences can lead to a general increase of the threshold of defensive system reaction to stimulation. Dopamine action on the defensive behaviour command neurones is significantly weakened in serotonine presence. Against the dopamine background, the efficiency of serotonine influence on the value of EPSP in command neurones in response to testing stimulus is reduced. According to the obtained data, a conclusion is made that interrelation of dopamine and serotonine concentrations can be a base for formation of behaviour choice in snail.

[Effect of serotonin on the activity of the neurons involved in the realization of the avoidance reflex of the snail]. / Vliianie serotonina na aktivnost' neironov, vkliuchennykh v osushchestvlenie oboronitel'nogo refleksa ulitki.

Bath application of 10(-5) mol/l of serotonin (5-HT) elicited a 50% increase of summary EPSPs recorded in command neurones for avoidance behaviour. No significant changes of rest potential and input resistance were seen in these cells. 5-HT evoked an increase of spontaneous level of firing in motoneurones involved in the same reflex, as well as an increase in the number of spikes which paralleled increase of EPSPs to the same stimulus in command neurones. In sensory cells, presynaptic to the command neurones, application of 5-HT evoked a significant increase of excitability and of input resistance. Monosynaptic EPSPs recorded in the command neurones showed a 40% increase after serotonin application. It is concluded that the major locus of plastic changes evoked by 5-HT application in the neuronal chain underlying avoidance reflex is the synaptic contact between sensory and command neurones.

[Nonspecific changes in the response of command neurons in Helix leucorum L. to a combination of 2 stimuli]. / Nespetsificheskie izmeneniia reaktsii komandnykh neironov vinogradnoi ulitki pri sochetanii dvukh stimulov.

In a preparation of isolated nervous system of the snail (Helix leucorum L.) an analogue of conditioned food aversion reflex was reproduced using electrical stimulation of the chemoreceptive pathway as conditioned and stimulation of skin innervating nerves as unconditioned stimuli. In 65% of cases, pairing of these stimuli elicited a significant increase of synaptic potential amplitude evoked by the conditioned stimulus in command neurones of avoidance behaviour and/or appearance of action potentials. In 20% of cases in which reinforcement evoked less than 5 spikes, no increase of response to unconditioned stimuli was recorded. In 15% of cases in which no response of command neurones to stimulation of the chemoreceptive pathway was recorded, no changes were observed with any reinforcement. Nonassociative character of responsiveness changes was established in experiments with presentation of conditioned and unconditioned stimuli at random or of isolated unconditioned stimuli: these procedures evoked exactly the same changes as in experiments with temporal pairing of two stimuli.

[Role of serotonin in the development of the defensive reflex to food in the snail]. / Rol' serotonina v formirovanii oboronitel'nogo refleksa na pischu u ulitki.

9-16 days after injection of 5,7-dihydroxytryptamine which elicits degeneration of serotonergic nerve cell terminals, pairing of food and electrical shock had no effect on responses of injected animals to food, while definite food-aversive reactions were observed in control animals. In neurophysiological experiments applications of serotonin in the chamber containing the nervous system was used as a reinforcing stimulus. The amplitude of synaptic responses to nerve stimulation increased significantly in preparations in which stimulation was paired with serotonin application. In neurons involved in defensive reactions after 3-7 pairings of a drop of juice to the chemoreceptive part of the skin with serotonin application a new spike response to food has appeared. Unpaired presentations of the same stimuli were not effective. It is concluded that serotonin is an important factor in formation of conditioned adverse reactions in the snail.