First Observation of Neutral Bremsstrahlung Electroluminescence in Liquid Argon.

A recent discovery of additional mechanism of electroluminescence (EL) in noble gases due to the neutral bremsstrahlung (NBrS) effect led to a prediction that NBrS EL should be present in noble liquids as well. A theoretical model of NBrS EL in noble liquids was developed accordingly in the frameworks of Cohen-Lekner and Atrazhev. In this work, we confirm this prediction: For the first time, visible-range EL has been observed in liquid argon at electric fields reaching 90 kV/cm, using gas electron multiplier (GEM) and thick GEM structures. Absolute light yields of the EL were measured and found to be in excellent agreement with the theory, provided that the momentum-transfer cross section of electron scattering is used for calculation of the NBrS cross section (instead of the energy-transfer one).

[Atrial Flutter: up-to-date Problem Evaluation with Clinical Positions].

The review provides current ideas about the etiology and prevalence of atrial flutter (AF), mechanism and substrate of arrhythmogenesis, and principles of clinical and electrophysiological classification of this arrhythmia. Methods for conservative and surgical treatments of AF, including their comparative aspect, are described in detail. The review presented recent data on efficacy and potential risks of different approaches to reversing the arrhythmia. The authors indicated a need for early diagnosis and strict control of the sinus rhythm in AF, which would help a successful intervention not only to completely cure the existing arrhythmia but also to prevent other heart rhythm disorders, primarily atrial fibrillation.

[Efficacy and safety of new oral anticoagulants as part of triple antithrombotic therapy in patients with atrial fibrillation and acute coronary syndrome. Data from an observational study].

Aim To study efficacy and safety of a triple antithrombotic therapy with direct oral anticoagulants (DOAC) versus warfarin in patients with atrial fibrillation after acute coronary syndrome, for 12 months following discharge from the hospital.Materials and methods This single-site cohort, prospective, observational study performed at the Regional Vascular Center 2 of the N.A. Semashko Nizhniy Novgorod Regional Clinical Hospital included 402 patients. It was possible to maintain contacts with 206 patients for 12 months. These patients were divided into two groups, the DOAC treatment (n=105) and the warfarin treatment (n=101) as a part of triple antithrombotic therapy upon discharge. Clinical observation was performed at 1, 3, 6, and 12 months after the discharge by structured telephone interview. Predetermined efficacy endpoints included cardiovascular death, myocardial infarction, stent thrombosis, and ischemic stroke. Safety endpoints included bleeding defined as small, medium (clinically significant), and major in accordance with the TIMI classification.Results At 12 months of follow-up, 80 patients (76.19%) continued taking DOAC and 39 patients (38.61%, p<0.001) continued taking warfarin; in this process, only 25 patients (24.75%) monitored their INR on a regular basis. With a regular INR monitoring and TTR >70%, death rate did not differ in the warfarin and the DOAC treatment groups. However, there was a difference in reaching the composite efficacy endpoint (p=0.048): ischemic events occurred statistically significantly more frequently in the warfarin treatment group than in the DOAC treatment group.Conclusions In 12 months after discharge from the hospital, compliance with the DOAC treatment as a part of the antithrombotic therapy was significantly higher than compliance with the warfarin treatment. The triple antithrombotic therapy with DOAC was safer than the warfarin treatment by the number of hemorrhagic complications and more effective in prevention of ischemic events, primarily due to no need for monitoring of lab test values.

[Double antiplatelet therapy in patients with acute coronary syndrome after percutaneous coronary intervention: individual efficacy and hemorrhagic safety of P2Y12 blockers of ticagrelor and clopidogrel in actual clinical practice].

AIM: To study the comparative efficacy and safety of clopidogrel and ticagrelor in the "double" antiplatelet therapy (DATT) in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) in the early and late periods in real clinical practice, and to assess adherence to treatment. MATERIALS AND METHODS: The study included 109 patients with ACS, who underwent PCI. Patients were divided into two groups: the 1st group (n=57) - received ticagrelor and the 2nd group (n = 52) - received clopidogrel in the DATT for 12 months. The frequency of ischemic events (death from cardiovascular causes, repeated myocardial infarction (MI) and stent thrombosis (ST)) and hemorrhagic events was analyzed during hospitalization, in 3 months, 6 months and in 12 months. Also, the reasons of repeated hospitalizations during the year were analyzed. The adherence of patients was assessed using the Moriski-Green scale. RESULTS: There were no significant differences in the ticagrelor and clopidogrel groups (8.8% vs. 11.5%, p=0.87) for the incidence of stent thrombosis (ST). In the correlation analysis, in half of all cases of subacute ST in the total sample (n=109) (in 4 (3.65%) cases from 8 (7.3%)), the main reason for its development was the lack of adherence of patients to DATT (τ=0,6; p<0,001). The frequency of minor bleeding significantly prevailed in the ticagrelor group versus the clopidogrel group (38.6% vs. 21.2%, p=0.047). No significant difference in the rates of major bleeding was found between the ticagrelor and clopidogrel groups (1.8% and 1.9%, p=0.52). However, the difference in the rates of fatal bleeding, including more instances of fatal intracranial bleeding (1.8% vs. 0%; p=0,34), allows us to talk about the best hemorrhagic safety of clopidogrel. CONCLUSION: In this study, ticagrelor and clopidogrel were comparable in their effectiveness. Ischemic events and repeated hospitalizations in both groups are associated with the progression of atherosclerosis, confirmed by angiography; the development of stent restenosis, as well as low adherence, which is the main predictor of subacute TS. In addition, clopidogrel versus ticagrelor showed better hemorrhagic safety in the frequency of development of minor bleeding.

[Multifactorial Prognostication of the Development of Stent Thrombosis in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention on the background of Dual Antiplatelet Therapy].

AIM: to identify predictors of stent thrombosis in patients with acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) for 12 months by creating a miathematical logistic regression model to optimize rehabilitation, secondary prevention of ischemic events in the first year after ACS, as well as a personalized approach to treatment. MATERIALS AND METHODS: The analysis used data from the hospital register, which contained information on all PCIs, performed in the Semashko hospital between September 2016 and August 2018 (2378 patients). For this study we selected a sample of 183 ACS patients (146 men and 37 women) after PCI: 25 with definite stent thrombosis confirmed by repeated coronary angiography (CAG) (the main study group), and 158 without developing definite stent thrombosis (the comparison group) according to the observation for 12 months. All patients during hospitalization and 1 year after discharge received standard medical therapy ACS, according to international recommendations. Laboratory tests, electrocardiography (ECG), echocardiography, 24-hour ECG monitoring were performed for in patients. For determining predictors of the development of stent thrombosis we performed a logistic regression analysis. RESULTS: A mathematical model of multifactorial prognostication of stent thrombosis in patients with ACS after PCI was created. The model included the following predictors: Killip class >II; life-threatening paroxysmal tachyarrhythmias (atrial fibrillation and/or ventricular fibrillation) as ACS complication of; left ventricular ejection fraction ≤45%; CA dissection; CAG confirmed CA thrombosis before PCI. CONCLUSION: The proposed model in patients with ACS allows us to estimate the risk of stent thrombosis after PCI, as well as to improve the accuracy of the event prediction. The model is easy to use, can be applied by practicing cardiologists during hospitalization. This model allows us to personalize secondary prevention in the first year after ACS, and thus help to reduce cardiovascular mortality, incidence of recurrent myocardial infarctions, unstable angina, and emergency revascularization.

[Major predictors of stent thrombosis in patients with acute coronary syndrome following transcutaneous coronary intervention who received different double antiplatelet therapy].

The review analyzes the reports addressing from different standpoints the issue of stent thrombosis and its major predictors in patients with acute coronary syndrome following transcutaneous coronary interventions. The review focuses on comparative efficacy and safety of ticagrelor and clopidogrel and the effect of double antiplatelet therapy on stent thrombosis. The issue of patients' compliance with double antiplatelet therapy is also discussed. Such comprehensive evaluation is warranted since despite all efforts for expanding both technical and therapeutic possibilities, the issue of stent thrombosis remains relevant.

[Issues of antithrombotic therapy in ACS patients with atrial fibrillation].

The review analyzed current ideas on prevalence and clinical significance of atrial fibrillation following acute coronary syndrome; described modern approaches to administration of antithrombotic therapy; and addressed available clinical studies on the treatment with warfarin and new oral anticoagulants as a part of combination antithrombotic therapy in patients with atrial fibrillation and acute coronary syndrome.

Causes of non-Kolmogorov turbulence in the atmosphere.

In the present work, we briefly describe a model for atmospheric turbulence energy on the basis of experimental data obtained in Siberia. A series of new studies is considered and the results of our long-term experimental observations are summarized. The results of these studies form the basis for an explanation of some effects in interactions between optical waves and atmospheric turbulence. Our numerous experimental results point to the possible generation of so-called coherent turbulence in the atmosphere. When analyzing the problem, we proceeded based on our own experimental data and comprehension that the coherent turbulence is a result of the action of self-organizing nonlinear processes, which run in continuous media, including atmospheric air. The experimental data confirmed the effect of attenuation of light fluctuations in coherent turbulence.

Features of optical image jitter in a random medium with a finite outer scale.

For more than 40 years, we have studied the effect of the low-frequency spectral range of atmospheric turbulence on optical characteristics. We also have looked at the influence of the turbulence models as well as an outer scale of turbulence on the parameters of telescopes and systems of laser beam formations. This question is important mainly for ground-based astronomy. Here we propose what we believe is a new optical method that uses the phase fluctuations of optical image jitter to estimate both the integral (along an atmospheric path) value of the structure parameter of atmospheric turbulence and effective outer scales of turbulence.

Comparison of Kolmogorov's and coherent turbulence.

Features of optical wave fluctuations while propagating through a randomly inhomogeneous turbulent medium with a finite outer scale are considered, including conditions when areas with dominating influence of one large-scale coherent structure are observed in the atmosphere, for which the spectrum of atmospheric turbulence can differ significantly from the Kolmogorov model spectrum. Using an approximate model of the spectrum for coherent turbulence, described earlier in our works, the variance of jitter of an optical image is calculated (under the applicability condition for the smooth perturbation method). The comparison of these equations with known similar equations for Kolmogorov turbulence has shown that the variance of fluctuations is significantly weaker in coherent turbulence than in the Kolmogorov theory under similar conditions. This means that phase fluctuations of optical radiation decrease significantly in coherent turbulence. The importance of this conclusion is noted for interpretation of the results of optical sounding of atmospheric turbulence.

Occurrence of hydrodynamic cavitation.

In this paper, the conditions under which cavitation (or liquid film rupture) can or cannot occur in thin layers of moving liquid are derived for three typical cases. At the same time, expressions depending on geometrical and movement parameters, where cavitation might start, are given. The results are obtained using simple engineering terms, which can be used in cases whether it is necessary to avoid cavitation or to induce it.

Relationship between the expression of VEGF signal components and matrix metalloproteinases in ovarian tumors.

The content of vascular endothelium growth factor is significantly increased, while the level of matrix metalloproteinase-2 is 2-fold reduced in ovarian cancer tissue compared to benign tumors. A trend to an increase in the levels of matrix metalloproteinases 7 and 9 and reduction of vascular endothelial growth factor type 2 receptors in tumor tissue was also detected. A highly significant negative correlation between the levels of vascular endothelial growth factor and matrix metalloproteinase 2 and positive correlations between vascular endothelial growth factor and matrix metalloproteinase 7, vascular endothelial growth factor and matrix metalloproteinase 9, matrix metalloproteinase 2 and vascular endothelial growth factor type 2 receptors were revealed. In the tumors assayed after preoperative therapy, relative normalization of the studied parameters was observed: the level of vascular endothelial growth factor decreased significantly, while the levels of matrix metalloproteinase 2 and vascular endothelial growth factor type 2 receptors increased. The levels of the markers differed significantly in ovarian tumors of different histological types, and the levels of vascular endothelial growth factor type 2 receptors were higher in patients with stage III compared to stage I and the content of matrix metalloproteinase 7 was higher in stage III compared to stage II cancer.

[The condition of vascular-thrombocyte hemostasis in the elderly with arterial hypertension].

The aim of the study was to analyze the main parameters of vascular-thrombocyte hemostasis in patients with systolo-diastolic and isolated systolic arterial hypertension (SDAH and ISAH) aged over 65 years. The subjects were 201 elderly patients with AH. The study revealed that uncomplicated AH in the elderly was characterized by activation of vascular hemostasis and increase of thrombocyte aggregation ability, manifested by the increase of Willebrand factor level, the presence of spontaneous and irreversible aggregation, coincidence of the first and the second waves of aggregation, and intensification of aggregation in response to "moderate" and "strong" inductors. Unlike ISAH, uncomplicated SDAH in the elderly is characterized by noticeable prevalence of night-peakers in the day profile of arterial pressure, and is accompanied by more pronounced thrombocyte hyperfunction; this difference should be taken into account while administering disaggregation therapy.

[The immunological aspects of maternal-fetal interrelationships]. / Immunologicheskie aspekty materinsko-plodovykh vzaimootnoshenii.

The paper deals with different aspects of the relationships occurring between the pregnant woman and the fetus having paternal antigens. Analysis of a great deal of recent information clearly indicates that local uterine immunity plays a great role during pregnancy. The specific features of the gene expression of major histocompatibility by an invasive trophoblast and the immunosuppressive function of placental fibrinoid are discussed. A detailed account of the immunocompetent cells, including T lymphocytes, giant granular lymphocytes, and macrophages, that are involved in immunological responsiveness within the decidua is given.

[Mathematical model of the sinus rhythm of the heart]. / Issledovanie matematicheskoi modeli sinusovogo ritma serdtsa.

As a result of mathematical simulation a group of signs was formed necessary and sufficient for the description of the oscillatory structure of the cardiac sinus rhythm at the quasi-stationary sections of the recording. The practical employment of the "adjustable" model permits one to obtain the present statistical accuracy of the assessment of signs with a lesser amount of baseline data. A procedure for the automatic measurement of signs by a mini-computer has been elaborated.

[Relationship of variability of blood pressure, cardiac sinus rhythm, and structural and functional characteristics of the left ventricular myocardium in elderly and senile patients with arterial hypertension]. / Vzaimosviaz' variabel'nosti arterial'nogo davleniia, sinusovogo ritma serdtsa i strukturno-funktsional'nykh kharakteristik miokarda levogo zheludochka u bol'nykh arterial'noi gipertoniei pozhilogo i starcheskogo vozrasta.

The variability of blood pressure (BP), autonomic cardiac sinus rhythm regulation, and myocardial structural and functional characteristics of the left ventricle (LV) was comparatively analyzed in 201 patients aged 65-88 years who had uncomplicated systolic and diastolic and isolated systolic arterial hypertension (SDAH and ISAH, respectively). There was a greater variability of systolic and diastolic BP no matter what the type of arterial hypertension (AH) was. It was ascertained that ISAH was characterized by absolute parasympaticotonia and SDAH was marked by relative sympaticotonia with the involvement of central ergotropic and humoral-and-metabolic mechanisms. In elderly and senile patients, uncomplicated AH was accompanied in 86.6% of cases by LV remodeling, mainly as its concentric hypertrophy (52.7%), characterizing primarily by non-restrictive diastolic dysfunction. There were no significant differences in the types of LV remodeling and diastolic dysfunction in patients with combined AH and ISAH. Moreover, the development of LV remodeling and associated diastolic dysfunction in SDAH was followed by a decrease in the overall variability of cardiac sinus rhythm with a smaller contribution of a segmental link of the parasympathetic portion of the autonomic nervous system and by the development of relative sympaticotonia due to suprasegmental and humoral-and-metabolic influences.

[Radical surgical treatment of patients with complicated forms of acute paraproctitis]. / Radikal'noe khirurgicheskoe lechenie bol'nykh so slozhnymi formami ostrogo paraproktita.

The authors discuss the results of surgical treatment of 412 patients with complicated forms of acute paraproctitis. They found that one-stage radical surgical treatment may be performed in most patients. With strict observance of indications for each type of operative measures, careful surgical techniques, and effective treatment of the purulent operative wound, not only may the period of treatment be shortened but, which is most important, the incidence of postoperative complications may be considerably reduced and the best end results of the management of this most serious group of patients be achieved. But the authors also do not exclude the tactics of two-stage treatment.

[Treatment of patients with bleeding hemorrhoids]. / Lechenie bol'nykh s gemorroidal'nymi krovotecheniiami.

The article discusses the choice of the optimal therapeutic tactics, the volume of preoperative examination, and the rational techniques of surgical treatment in 65 patients with profuse bleeding from the hemorrhoids. It is shown that digital examination, proctosigmoidoscopy, as well as adequate examination of the whole large intestine must be undertaken without fail in this group of patients. Assessment of the volume of blood loss, its correction under hemoglobin control, and consideration for the patient's general condition allows radical operative treatment to be conducted in the majority of cases (96.4%). Good results were produced with the use of advanced surgical techniques of hemorrhoidectomy.

[Computer treatment of strabismus and amblyopia using random-dot stereograms]. / Komp'iuternoe lechenie kosoglaziia i ambliopii s primeneniem sluchaino-tochechnykh stereogramm.

Application interactive CLASS software for stimulating productive binocular cooperation based on random-dot patterns and stereograms was used for treating strabismus and amblyopia in 105 children during a standard course of treatment. The children were divided into 3 groups treated by the CLASS alone (1), Class + two other application programs (2), and CLASS + traditional methods. General positive changes (improvement of visual acuity, decrease of eye deviation, etc.) were similar in these 3 groups. Positive effect of CLASS exercises on binocular visual mechanisms was significant. Due to precise evaluation of binocular interaction provided by CLASS, positive changes in binocular cooperation and stereovision were attained in 93% of children.