[Acute myocardial infarction and cardiogenic shock in patient with COVID-19].

The conditions of the pandemic caused by the novel coronavirus infection (COVID-19) are associated with overloading intensive care units, conversion of hospitals, and changes in routing of patients with acute cardiovascular pathology. At the same time, medical practice is still challenged to provide medical care to patients with acute coronary syndrome (ACS). Patients with COVID-19 and acute myocardial infarction (AMI) are at a higher risk of death while the incidence of this combination of diseases will be growing. This article describes a case of diagnosis and treatment of COVID-19 in a 69-year-old patient who was urgently hospitalized with cardiogenic shock associated with ACS, electrocardiographic signs of complete left bundle branch block, and left ventricular ejection fraction of 19 %. Coronary angiography with stenting was successfully performed in the conditions of extracorporeal membrane oxygenation. The patient received long-term intensive therapy in the intensive care unit followed by symptomatic treatment in the cardiac surgery unit. The patient's condition gradually improved and he was discharged from the hospital on the 56th day. The strategy of intensive care and active follow-up helped saving life of the patient with COVID-19 and AMI.

[Aortic valve replacement via J-shaped partial upper sternotomy: randomized trial, mid-term results]. / Effektivnost' i bezopasnost' protezirovaniya aortal'nogo klapana cherez «mini-J¼ sternotomiyu: randomizirovannoe issledovanie, sredne-otdalennye rezul'taty.

OBJECTIVE: To evaluate the effectiveness and safety of aortic valve replacement through upper partial J-shaped sternotomy compared to conventional sternotomy. MATERIAL AND METHODS: There were 240 procedures of isolated aortic valve replacement for the period 2012-2017. According to inclusion criteria, 112 patients were randomized into 2 groups: group I - median sternotomy, group II - upper partial J-shaped sternotomy. Mean age of patients was 56.1±14.3 and 53.1±14.9 years, respectively (p=0.284). Females prevailed in both groups (55.4% vs. 57.1%, p=0.848). Peak pressure gradient on the aortic valve was 106.2±23.9 and 102.8±25.3 mm Hg, respectively (p=0.484). RESULTS: In-hospital mortality was 1.8% (n=1) in group I (p=0.315). Incidence of postoperative complications (complete atrioventricular blockade, ventricular septal defect) was similar (p=1.0). Mean time cross clamping in I and II groups was 65.5±12.5 and 64.7±13.1 min (p=0.729). Mean follow-up period was 31.6 and 33.5 months, respectively. Kaplan-Meier survival rate was 92.6 and 93.0%, respectively (log-rank test=0,767). Freedom from thromboembolic events was 91.7 and 90% (log-rank test=0.213). CONCLUSION. U: Pper partial J-shaped sternotomy is safe and effective for aortic valve surgery and characterized by similar outcomes compared to conventional sternotomy.

[Immediate and intermediate results of staged carotid endarterectomy in combination with coronary artery bypass grafting]. / Neposredstvennye i sredneotdalennye rezul'taty étapnykh operatsii na sonnykh arteriiakh v sochetanii s koronarnym shuntirovaniem.

The purpose of our investigation was to evaluate the immediate and intermediate results of staged operations of carotid endarterectomy and coronary artery bypass grafting in patients with multifocal atherosclerosis. We analysed a total of 475 operations. Of these, 371 (78.1%) patients underwent staged interventions (stage 1 - carotid endarterectomy, stage 2 - coronary artery bypass grafting). No neurological complications were observed after stage 1. Five (1.3%) patients developed cardiac arrhythmia in the form of atrial fibrillation, 7 (1.9%) were found to have transient neuropathy of cranial nerves. There were no lethal outcomes. Stage 2 was carried out 16±13 days after carotid endarterectomy. Of complications encountered, mention should be made of perioperative myocardial infarction in 1 (0.3%) patient, with 2 (0.6%) patients requiring emergency coronary bypass angiography. Newly onset atrial fibrillation was registered in 71 (19.1%) patients, haemorrhage followed by resternotomy in 6 (1.6%), and purulent wound complications in 4 (1.1%) patients. Death occurred in 1 (0.3%) patient. We also analysed the mid-term postoperative results (up to 32 months). The coverage amounted to 151 patients. The incidence rate of major adverse cardiac and cerebrovascular events (MACCE) was 6% (myocardial infarction - 2, acute cerebral ischaemia - 1, repeat myocardial revascularization - 5, lethal outcome - 1). Based on the obtained findings it may be concluded that staged operations on the carotid basin and coronary arteries by the number of complications are comparable to those after isolated coronary artery bypass grafting.

[Risk factors for progression of atherosclerosis of the shunted coronary artery in the remote postoperative period]. / Faktory riska progressirovaniia ateroskleroza shuntiruemoi koronarnoi arterii v otdalennom periode.

The study was aimed at revealing risk factors for progression of atherosclerosis in the shunted coronary artery in the remote period following coronary artery bypass grafting. Our prospective study included a total of 292 patients having endured coronary artery bypass grafting. All patients were divided in two groups depending on the type of the bypass grafts used: either autoarterial shunts (Group 1) or autovenous grafts (Group 2). We thus assessed a total of 516 autoarterial grafts and 257 autovenous grafts, as well as the coronary arteries shunted thereby. The long-term results were evaluated by means of coronaroshuntography performed not earlier than 12 months after surgery. The average duration of follow up amounted to 53.4±26.5 months. Analysing the cumulative risk for progression of atherosclerosis in the arteries shunted demonstrated that for autoarterial grafts the rate of the development of proximal stenosis of the coronary artery (CA) shunted was lower compared with autovenous grafts (p≤0.001). The Cox regression model showed that an autovein used as a graft increased the risk for the development of occlusion of the shunted CA by 43% from the baseline each postoperative month. The presence of proximal stenosis of the shunted coronary artery amounting to or exceeding 90% increases the risk of occlusion by 68% per month. Also, for the patients with the SYNTAX scoring ≥ 32 points the risk of coronary artery occlusion increases 2.2-fold each month after the operation. Such factors as the patient's gender, the diameter of the shunted artery, diabetes mellitus, tobacco smoking, multifocal atherosclerosis by the findings of the study exerted no influence on the progression of proximal stenosis of the shunted coronary artery.

Manipulation of polarization and spatial properties of light beams with chiral metafilms.

Two-dimensional lattices of chiral nanoholes in a plasmonic film with lattice constants being slightly larger than light wavelength are proposed for effective control of polarization and spatial properties of light beams. Effective polarization conversion and strong circular dichroism in non-zero diffraction orders in these chiral metafilms are demonstrated by electromagnetic simulations. These interesting effects are found to result from interplay between radiation pattern of single chiral nanohole and diffraction pattern of the planar lattice, and can be manipulated by varying wavelength and polarization of incoming light as well as period of metastructure and refractive indexes of substrate and overlayer. Therefore, this work offers a novel paradigm for developing planar chiral metafilm-based optical devices with controllable polarization state, spatial orientation and intensity of outgoing light.

[Indices of intraoperative flowmetry, determining patency of grafts in the remote period after revascularization of the right coronary artery].

The authors studied the threshold values of ultrasound flowmetry concerning composite T-grafts, combined I-grafts, and autovenous shunts during revascularization of the right coronary artery (RCA), determining high risk for the development of shunt occlusion in the remote postoperative period. The retrospective study included a total of 223 patients subjected to revascularization of the RCA's basin with the help of composite T-grafts, combined I-grafts, and autovenous shunts. Depending on the method of bypass grafting of the RCA and its branches, all patients were subdivided into 3 groups: Group 1 was composed of 65 patients in whom the RCA basin was revascularized by a branch of the composite T-graft, Group 2 comprised 112 patients who endured autovenous aortocoronary bypass grafting, and Group 3 consisted of 46 patients in whom the RCA basin was shunted by a combined mammarovenous I-graft. The groups had no statistically significant differences on the main clinical and demographic parameters. Intraoperative assessment of the blood flow through the coronary shunts was carried out by means of ultrasound flowmetry. The remote results were evaluated based on the findings of the control coronaroshuntography which was carried out in all patients within the terms varying from 16 to 43 months. In the remote period in Group 1 patients (T-graft), 59 (90%) mammary shunts were patent, in Group 2 - 99 (88.4%) autovenous shunts, and in Group 3 (I-graft) 42 (95.5%) shunt were patent. Cumulative probability of freedom from shunt occlusion within the terms up to 3 years after surgery in Group 1 amounted to 82±0.5%, in Group 2 to 58±2.1%, and in Group 3 to 86±1.9%, with the differences between Group 2 and other groups being statistically significant (p=0.01). The Poisson regression analysis showed that the risk for graft occlusion increased by 10% with the resistance index in the branch of the T-graft from 4.0; by 8% with the resistance index in the autovein from 2.9; and by 3% with the index of resistance in the I-graft from 3.2. The conclusion was made that composite T-grafts and combined I-grafts demonstrated similar results of patency within the terms up to 3 years, possessing advantages over autovenous conduits while shunting the RCA basin. The optimal index of peripheral resistance for the autovein during revascularization of the RCA basin is up to 2.9; for the combined T-graft - up to 3.2, and for the composite T-graft - up to 4.0. Probability of shunt occlusion in the remote period does not depend upon the average volumetric blood velocity (Qmean) but is directly proportional to the value of the pulsatility index (Pi) which reflects the state of the distal bed.

[Flowmetric assessment of coronary bypass grafts in the conditions of artificial circulation and on the beating heart].

Advantages and shortcomings of aortocoronary bypass grafting on the beating heart and in the conditions of artificial circulation (AC) have long been discussed. The data on patency of bypass grafts in the remote period are indicative of comparable results of operations with and without AC or advantages of using AC. In order to determine benefits of each method it is necessary to reveal intraoperative predictors of bypass grafts occlusion in the remote period. We analyzed the results of ultrasound flowmetry of the blood flow through the left internal thoracic artery during bypass grafting of the anterior descending artery with the use of AC and on the beating heart. A retrospective study included a total of 352 patients subdivided into 2 groups: Group One was composed of 120 patients undergoing surgery in the conditions of AC and Group Two comprised 232 patients subjected to similar operations on the beating heart. Blood flow was measured with the help of flowmeter VeryQ MediStim® after termination of AC and inactivation of heparin by protamine, with systolic pressure of 100-110 mm Hg. There were no statistically significant differences between the groups by the diameter and degree of stenosis of the anterior descending artery, diameter of the left internal thoracic artery. The mean volumetric blood flow velocity (Qmean) along the shunts in Group One was higher (p=0.01). No statistically significant differences by the pulsatility index (PI) between the groups were revealed (p=0.2). A conclusion was drawn that coronary bypass grafting of the anterior descending artery by the left internal thoracic artery in the conditions of artificial circulation made it possible to achieve higher volumetric velocity of blood flow through the conduit as compared with operations on the beating heart, with similar resistance index. The immediate results of the operations with the use of the both techniques did not differ.

Eigen oscillations of a chiral sphere and their influence on radiation of chiral molecules.

Eigenmodes of a chiral sphere placed in a dielectric medium were investigated in details. Excitation of these eigenmodes by a plane wave and a chiral molecule radiation was studied both analytically and numerically. It was found that decay rates of "right" and "left" enantiomers are different in the presence of the chiral sphere. Strong dependence of radiation pattern of the chiral molecule placed in the vicinity of the chiral sphere on chirality strength was also demonstrated. An interesting correlation between chirality of sphere and spatial spirality (helicity, vorticity ...) of the electromagnetic fields in the presence of chiral sphere was observed for the first time.

Kinetics of nickel particle formation on silicon substrate with a buffer layer of niobium nitride.

The size, form and distribution function of catalyst particles define the quality of synthesized arrays of carbon nanotubes. In this work, we study the kinetics of catalyst particle formation from the thin nickel film (9 nm) deposited on the silicon substrate (SiO2/Si) with a buffer layer of niobium nitride at the temperature of 880 °C. In the experiment, we have obtained the time dependences of the average radius, average height and concentration of nickel particles. The experimental data are satisfactorily described by simulations based on the wetting transition theory. Comparison of the simulation results and experimental data allows us to estimate the effective interaction potential between the nickel film and buffer layer of niobium nitride. Besides, we have estimated the viscosity of the nickel confirming an undercooled liquid state of the nanosized nickel film at the temperature of 880 °C.

Role of Nitrogen and Oxygen in Capacitance Formation of Carbon Nanowalls.

Supercapacitors based on carbon nanomaterials are attracting much attention because of their high capacitance enabled by large specific surface area. The introduction of heteroatoms such as N or O enhances the specific capacitance of these materials. However, the mechanisms that lead to the increase in the specific capacitance are not yet well-studied. In this Letter, we demonstrate an effective method for modification of the surface of carbon nanowalls (CNWs) using DC plasma in atmospheres of O2, N2, and their mixture. Processing in the plasma leads to the incorporation of ∼4 atom % nitrogen and ∼10 atom % oxygen atoms. Electrochemical measurements reveal that CNWs functionalized with oxygen groups are characterized by higher capacitance. The specific capacitance for samples with oxygen reaches 8.9 F cm-3 at a scan rate of 20 mV s-1. In contrast, the nitrogen-doped samples demonstrate a specific capacitance of 4.4 F cm-3 at the same scan rate. The mechanism of heteroatom incorporation into the carbon lattice is explained using density functional theory calculations.

[Laparoscopic cardiomyotomy for the treatment of achalasia of esophagus in children].

The experience of endosurgical treatment of 8 children, aged from 4 to 15 years, with cardiac achalasia was analyzed. Laparoscopic Heller's cardiomyotomy with gastropexy was performed in all cases. Esophageal mucosa was damaged in 2 patients. The lesion was closed laparoscopically, there were no conversions. Esophageal perforation was registered postoperatively in one patient. The study shows capabilities of endoscopic surgery in treatment of rare esophageal diseases in children.

[Mini-laparoscopic fundoplication by Nissen in the treatment of gastroesophageal reflux at children].

Results of surgical treatment of 180 children with gastroesophageal reflux are analyzed. Laparoscopic fundoplication by Nissen was used. Positive result was achieved in all the cases, there were no lethal outcomes. Mean time of surgery was 64.4+/-30.2 min, mean hospital stay after operation--4.7+/-1.5 days. It is concluded that laparoscopic fundoplication may be performed at children irrespective of age and body mass, including at the patients with malformations and recurrence of disease.

[Endoscopic lung resection in children].

The experience of thoracic surgery department of a pediatric hospital Number13 is revised. The evolution of operative methods in minimally invasive thoracic surgery and most frequently used procedures in children lung surgery are described. The results of 26 thoracoscopic lung resections on account of inherited and acquired diseases are described. Actual problems of thoracoscopic surgery are discussed.

[Can microorganisms survive upon high-temperature heating during the interplanetary transfer by meteorites?].

One of the most important aspects of the problem of life transfer in the cosmic space is the resistance of microorganisms to high-temperature heating during the launch and entry into the atmosphere. The high-temperature limits of the survival of microorganisms were studied under conditions modeling the laungh from the Mars and the landing on the Earth. Two strain of E. coli K12 exposed to short heating pulse were studied in order to tind out if they could resist high temperature while being in the desiccated state. The procedure was performed in vacuum. It was found that a fraction of bacteria survive heating pulses up to 250 degrees C in vacuum, while similar heating at normal atmospheric pressure leads to the total sterilization of samples.

Mars atmosphere. The imprint of atmospheric evolution in the D/H of Hesperian clay minerals on Mars.

The deuterium-to-hydrogen (D/H) ratio in strongly bound water or hydroxyl groups in ancient martian clays retains the imprint of the water of formation of these minerals. Curiosity's Sample Analysis at Mars (SAM) experiment measured thermally evolved water and hydrogen gas released between 550° and 950°C from samples of Hesperian-era Gale crater smectite to determine this isotope ratio. The D/H value is 3.0 (±0.2) times the ratio in standard mean ocean water. The D/H ratio in this ~3-billion-year-old mudstone, which is half that of the present martian atmosphere but substantially higher than that expected in very early Mars, indicates an extended history of hydrogen escape and desiccation of the planet.

Organic molecules in the Sheepbed Mudstone, Gale Crater, Mars.

The Sample Analysis at Mars (SAM) instrument on board the Mars Science Laboratory Curiosity rover is designed to conduct inorganic and organic chemical analyses of the atmosphere and the surface regolith and rocks to help evaluate the past and present habitability potential of Mars at Gale Crater. Central to this task is the development of an inventory of any organic molecules present to elucidate processes associated with their origin, diagenesis, concentration, and long-term preservation. This will guide the future search for biosignatures. Here we report the definitive identification of chlorobenzene (150-300 parts per billion by weight (ppbw)) and C2 to C4 dichloroalkanes (up to 70 ppbw) with the SAM gas chromatograph mass spectrometer (GCMS) and detection of chlorobenzene in the direct evolved gas analysis (EGA) mode, in multiple portions of the fines from the Cumberland drill hole in the Sheepbed mudstone at Yellowknife Bay. When combined with GCMS and EGA data from multiple scooped and drilled samples, blank runs, and supporting laboratory analog studies, the elevated levels of chlorobenzene and the dichloroalkanes cannot be solely explained by instrument background sources known to be present in SAM. We conclude that these chlorinated hydrocarbons are the reaction products of Martian chlorine and organic carbon derived from Martian sources (e.g., igneous, hydrothermal, atmospheric, or biological) or exogenous sources such as meteorites, comets, or interplanetary dust particles. KEY POINTS: First in situ evidence of nonterrestrial organics in Martian surface sediments Chlorinated hydrocarbons identified in the Sheepbed mudstone by SAM Organics preserved in sample exposed to ionizing radiation and oxidative condition.

Irradiated interplanetary dust particles as a possible solution for the deuterium/hydrogen paradox of Earth's oceans.

Determining the source of Earth's oceans is a longstanding problem in planetary science. Possible sources of water include water ice or water of hydration of silicate minerals in the original material from which the bulk Earth accreted and water brought in by late-arriving planetesimals during the heavy bombardment period (4.5-3.8 Gyr ago) [Chyba, 1989, 1991]. Comets are an attractive source of water because their origin in the outer solar system is consistent with the long timescale for heavy bombardment. However, the high deuterium/hydrogen (D/H) ratio of the three comets that have been studied, Halley, Hyakutake, and Hale-Bopp, indicates that Earth must have had a source with a low-D/H ratio as well. Here we suggest that solar wind-implanted hydrogen on interplanetary dust particles (IDPs) provided the necessary low-D/H component of Earth's water inventory.

Greenhouse warming by CH4 in the atmosphere of early Earth.

Earth appears to have been warm during its early history despite the faintness of the young Sun. Greenhouse warming by gaseous CO2 and H2O by itself is in conflict with constraints on atmospheric CO2 levels derived from paleosols for early Earth. Here we explore whether greenhouse warming by methane could have been important. We find that a CH4 mixing ratio of 10(-4) (100 ppmv) or more in Earth's early atmosphere would provide agreement with the paleosol data from 2.8 Ga. Such a CH4 concentration could have been readily maintained by methanogenic bacteria, which are thought to have been an important component of the biota at that time. Elimination of the methane component of the greenhouse by oxidation of the atmosphere at about 2.3-2.4 Ga could have triggered the Earth's first widespread glaciation.

Mass-independent fractionation of sulfur isotopes in Archean sediments: strong evidence for an anoxic Archean atmosphere.

Mass-independent fractionation (MIF) of sulfur isotopes has been reported in sediments of Archean and Early Proterozoic Age (> 2.3 Ga) but not in younger rocks. The only fractionation mechanism that is consistent with the data on all four sulfur isotopes involves atmospheric photochemical reactions such as SO2 photolysis. We have used a one-dimensional photochemical model to investigate how the isotopic fractionation produced during SO2 photolysis would have been transferred to other gaseous and particulate sulfur-bearing species in both low-O2 and high-O2 atmospheres. We show that in atmospheres with O2 concentrations < 10(-5) times the present atmospheric level (PAL), sulfur would have been removed from the atmosphere in a variety of different oxidation states, each of which would have had its own distinct isotopic signature. By contrast, in atmospheres with O2 concentrations > or = 10(-5) PAL, all sulfur-bearing species would have passed through the oceanic sulfate reservoir before being incorporated into sediments, so any signature of MIF would have been lost. We conclude that the atmospheric O2 concentration must have been < 10(-5) PAL prior to 2.3 Ga.