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Abstract The $$K^{+} \rightarrow \pi ^{+}\pi ^{0}\pi ^{0}\gamma $$ K + → π + π 0 π 0 γ decay is observed by the OKA collaboration. About 60 events of the decay observed with signal:noise $$\approx 1$$ ≈ 1 . The branching ratio obtained by normalization to $$K^{+} \rightarrow \pi ^{+}\pi ^{0}\pi ^{0}$$ K + → π + π 0 π 0 is measured to be $$(3.7 \pm 0.9(stat) \pm 0.3(syst))\times 10^{-6}$$ ( 3.7 ± 0.9 ( s t a t ) ± 0.3 ( s y s t ) ) × 10 - 6 for $$E_{\gamma }^*>10\,\textrm{MeV}$$ E γ ∗ > 10 MeV . The branching ratio, $$\gamma $$ γ energy spectrum and angular distribution are consistent with ChPT prediction.

Abstract A high-statistics data sample of the $$K^{+}$$ K + decays is recorded by the OKA collaboration. A missing mass analysis is performed to search for a light invisible pseudoscalar axion-like particle (ALP) a in the decay $$K^{+} \rightarrow \pi ^{+} \pi ^{0} a$$ K + → π + π 0 a . No signal is observed, and the upper limits for the branching ratio of the decay are calculated. The $$90\%$$ 90 % confidence level upper limit changes from $$2.5\cdot 10^{-6}$$ 2.5 · 10 - 6 to $$2\cdot 10^{-7}$$ 2 · 10 - 7 for the ALP mass from 0 to 200 MeV/ $$c^{2}$$ c 2 , except for the region of $$\pi ^{0}$$ π 0 mass, where the upper limit is $$4.4\cdot 10^{-6}$$ 4.4 · 10 - 6 .

Purpose. Analysis of the results of weakening of previously operated internal rectus muscle by the method of Z-shaped marginal myotomy.Patients and methods. The study included 87 children with an initially large-angle of strabismus. Children age — from 2 to 14 years (average age — 9.09 ± 0.78 years). The initial strabismus angle was from 30° to 60° according to Girschberg (average angle — 45.7° ± 2.3°). All children underwent a staged surgical treatment — recession of the internal rectus muscle and resection of the external rectus muscle in both eyes. The residual deviation angle after two stages of surgical treatment ranged from 6° to 10° (on average up to 9.1° ± 0.75°) according to Girschberg. All patients underwent a Z-shaped marginal myotomy on the operated internal rectus muscle. The follow-up period after surgery ranged from 1 year to 5 years.Results. A satisfactory anatomical result (orthotropy) was achieved in 91 % of cases (79 children), hypocorrection in 9 % of cases (8 children), hypercorrection — 0 %. In 8 patients with hypocorrection, after 6–8 months, the fourth stage of surgical treatment was performed with the method of Z-shaped marginal myotomy of the internal rectus muscle in the paired eye, after which orthotropy was achieved.Conclusion. An analysis of the surgical treatment results of operated esotropia have showed that the method of Z-shaped marginal myotomy makes it possible to weaken the tone of the previously operated internal rectus muscle with minimal trauma. Using the method of Z-shaped marginal myotomy in the treatment of residual-angle strabismus, orthotropy is achieved while preserving the biomechanics of the oculomotor muscles — the internal rectus muscle remains in the plane of its functional action. At initially large-angle of strabismus, conducting a Z-shaped marginal myotomy of the internal rectus muscle after stepwise surgical interventions on the horizontal rectus muscles of both eyes can be recommended as a modern, reliable and effective method of surgical treatment of residual-angle of strabismus, which allows to achieve the planned functional and cosmetic result.

Introduction. Carcinoid syndrome is the most common functional syndrome in patients with neuroendocrine tumors. More than 40 biochemical factors are responsible for the manifestation of carcinoid syndrome, among which serotonin is the most important. The study of biochemical markers of carcinoid syndrome and associated carcinoid heart disease is an important aim of laboratory examination in neuroendocrine tumors patients.Aim. Analysis of levels and diagnostic efficiency evaluation of chromogranin A (CgA), serotonin, pro-brain natriuretic peptide (proBNP) and platelet-derived growth factor (PDGF-BB) in the blood serum of neuroendocrine tumors patients with various clinical manifestations, including carcinoid syndrome and carcinoid heart disease.Materials and methods. 66 patients with neuroendocrine tumors of various localizations were examined (pancreas – 24 cases, small intestine – 21, large intestine – 6, lungs – 10, unkown primary focus – 5). 38 patients had liver metastases. In 43 patients, a clinic of carcinoid syndrome was observed, 16 had signs of carcinoid heart disease. The control group consisted of 30 practically healthy people. Serum levels of CgA, serotonin, and PDGF-BB were determined by enzyme immunoassay in microplate format: Chromogranin A NEOLISA (Eurodiagnostica, Sweden), Serotonin ELISA (IBL, German), and PDGF-BB ELISA Kit (Invitrogen, USA). The proBNP analysis was performed on a Cobas e601 automated analyzer (Roche, Switzerland).Results. In carcinoid syndrome, the medians of CgA, serotonin, and proBNP were the highest, differing statistically significantly from the control group. In patients with G3 tumors, the median PDGF-BB was statistically significantly higher than in controls, in contrast to G1 and G2. The highest diagnostic sensitivity in the general neuroendocrine tumors group was in CgA – 63.6 %, with a specificity of 100 %. In patients with carcinoid syndrome, the highest diagnostic sensitivity was characteristic of serotonin and chromogranin A (79 %), while in patients with CAD clinic, proBNP had the highest sensitivity – 93.8 %.Conclusion. The study revealed the high efficiency of СgA, with the highest sensitivity in common forms and tumors with high biological activity. Serotonin can be used in the diagnosis of carcinoid syndrome, associated with cardiofibrosis development. Pro-brain natriuretic peptide is a highly sensitive and specific marker of carcinoid heart disease. The highest levels of PDGF-BB are associated with a high grade of neuroendocrine tumors malignancy.

Mold fungi and the mycotoxins they produce have invariably accompanied humans, since the basis of its existence was agriculture, which allows to get more products than was necessary for consumption, as well as requiring the storage of crops between seasons. This provided a favorable ecological niche for molds, and stored agricultural products became the main source of mycotoxins in the diets of humans and farm animals. Since then, mycotoxins have been the cause of many large-scale poisonings and have caused significant damage to agriculture. The article provides a brief historical sketch and the most significant stages of the study of mycotoxins, which are the cause of frequent and large-scale lesions, reveals the specific circumstances that caused the researchers' keen interest in this group of substances. For a long time, the immediate cause of poisoning caused by mycotoxins remained unknown due to the weak technical equipment of researchers and the isolation of active substances was impossible, which, however, was not an obstacle to the development of methods to combat infection with mold fungi and poisoning caused by mycotoxins. The improvement of the technical base of research in the middle of the 20th century led to an increase in the number of discovered mycotoxins and the discovery of new toxic effects of already known compounds. Mycotoxins remain one of the most dangerous contaminants in both farm animal feed and food, despite the fact that in many countries they are subject to strict regulation and control. In the context of the increasing intensification of agriculture, a decrease in the species diversity of agricultural crops, the problem of the spread of mold fungi and, as a result, the degree of mycotoxin damage to agricultural products does not lose its importance, and the study of the history of the study of mycotoxins and their producers can provide important information on the spread of mold fungi in new economic conditions.

With the existing method for evaluating the effectiveness of masking objects with aerosols, two parameters are used: the length and width of an invisible smoke screen with a probability of at least 50 %. Both parameters were obtained during the practical tests of aerosol masking means. However, they are insufficient for assessing the masking ability of an aerosol cloud as a spatial formation. The purpose of this work is to reveal the analytical dependence of the probability of objects masking on the density and dispersion of the aerosol. Мaterials and methods. An extended approach was used to estimate the probability of masking at any theoretical value of the flux density (integral concentration, g/m2) of aerosol along the line of sight, taking into account its dispersion, by calculating the formation of a probability field from 5 to 95 % over the entire spatial structure of the aerosol cloud. The method used is the simulation on a PC of the dependence of the share of space occlusion for the observer (the eyepiece of an optical device) by aerosol particles of a given dispersion and flux density, which we took as the probability of masking. Discussion. It is shown in the article, that the resulting analytical expression as a result of processing the accumulated simulation results on a PC fully corresponds to the Bouguer-Lambert-Beer law, which is a generalization of many years of practical field and laboratory experiments with aerosols in the air and dispersed particles in solutions. The obtained probability values allow us to obtain a generalized efficiency criterion in the form of a new concept - the reduced masking zone. This term is mathematically analogous to the reduced impact zone, which is used to assess damage caused by munitions. Conclusion. For a full assessment of the effectiveness of aerosol countermeasures, the reduced masking zone must be calculated for all possible lines of sight (observation of an object): horizontally, vertically, and along inclined paths. This condition reflects the method of using modern weapons such as Javelin anti-tank systems, which are aimed at the target mainly horizontally, and the final trajectory before the impact is a «hill». The theoretical difference between the values of vertical and horizontal masking screens, obtained by the authors using a new method for calculating the parameters of an aerosol cloud, is presented in the illustrations to the article.

The paper examines the factors that contribute to the outperformance of mutual funds in relation to the market, with a particular emphasis on the macroeconomic indicators as the key variables of interest. The paper begins by providing a comprehensive literature review on various factors that can impact the performance of mutual funds. The discussion encompasses a wide range of topics, including skill presence, diseconomies of scale, and other challenges associated with generating excess returns for investors.In the second part of the paper, an empirical analysis is conducted using actively managed US mutual funds to establish a relationship between fund performance and macro-variables, specifically focusing on term and credit spreads. Furthermore, the study considers different returns on positive and negative changes in spreads. The sample consists of funds that primarily invest in various sectors within the United States, with the Standard and Poor's 500 (S&P 500) serving as the benchmark. To assess the performance of funds with active strategies, panel data models are applied, with the excess return over the benchmark as the dependent variable. Different subperiods, including the financial crisis and the COVID-19 period, are examined. Notably, the impact of variables during the pandemic period differs significantly from other subperiods. The findings indicate that positive and negative changes in the spread between corporate bond yields have significant and positive effects across almost all periods, which has practical implications for potential investors. It suggests that active professional portfolio managers have been successful in uncertain periods. To control for external shocks and funds' cross-correlation, double-clustered standard errors are employed, and a series of robustness checks confirm the stability of the results.

Background. The relevance of this development is due to the scientific popularity of the development of the use of neural networks and intelligent technologies in industry and the low efficiency of modern emergency protection systems, which have significant drawbacks, the main of which are "missing the target" and "false alarm". The purpose of this work is to improve the safety and technical and economic efficiency of existing control and management systems, based on the methods of the theory of developing processes with aggravation. Materials and methods. Within the framework of this study, methods of modern theory of automatic control, methods of identification of technological objects and methods of computer modeling were used. Results. The analysis of emergency situations developing in the mode with aggravation, the characteristic feature of which is the power law of development and three stages of accident development. The prediction of an emergency situation in the temperature control system of an electric generator was carried out using the method of sliding linearization, which allows to establish the beginning of its occurrence and to distinguish all three stages of the accident development. Conclusion. To achieve these goals, it is necessary to improve modern emergency protection systems. It is proposed to consider the development of the accident as a developing process with aggravation. For the analysis, it is proposed to use methods of sliding linearization of real time series, followed by forecasting the development of accidents.

Background. The study is devoted to the issue of improving the accuracy of automated measuring instruments for the electrical parameters of oxide coatings. In measuring instruments, integrating circuits based on an operational amplifier, which is a universal amplifying device, are used to perform linear mathematical operations on analog signals. The disadvantage of the integrating circuit is the use of an operational amplifier, when using which it is necessary to take into account many parameters and factors that can affect the output signal, and hence the accuracy of the measured value. Materials and methods. Methods of indirect measurement of voltage and current on the studied sample with an oxide coating using the proposed structures of measuring channels are presented. It is shown that the parameters of operational amplifiers have a significant influence on the additive and multiplicative errors of measurement results, for the analysis of which a linear model of an operational amplifier is considered. Results. Based on the metrological analysis of the voltage measurement channel on the test sample, formulas for estimating additive, multiplicative and nonlinear error components are obtained. The contribution of multiplicative and additive parameters of the operational amplifier to the error of measurement results is analyzed in detail. Conclusions. Metrological analysis of the equivalent circuit of an operational amplifier with feedback has been performed, which can be used to estimate additive and multiplicative errors of circuits based on operational amplifiers widely used in instruments and measuring systems. It is shown that the total relative error of the developed channels for measuring current and voltage does not exceed 0.5%, which makes it possible to measure these values of the studied oxide coatings with guaranteed accuracy.