Melatonin and its bioisosteres as potential therapeutic agents for the treatment of retinopathy of prematurity.

We conducted a study on the impact of intraperitoneal injections of melatonin and its three bioisosteres (compounds 1-3) on the development of oxygen-induced retinopathy in newborn rats during a 21-day experiment. It was demonstrated that melatonin and its analogues 1-3 effectively reduce the total protein concentration in the vitreous body of rat pups, decrease concentration of VEGF-A, and lower the level of oxidative stress (as indicated by normalization of antioxidant activity in the vitreous body). Melatonin and its analogues 1-3 equally normalize the level of VEGF-A. Analogues 1 and 2 even exceed melatonin in their ability to reduce protein influx into the vitreous body. However, analogue 2 had no effect on antioxidant activity, while analogues 1 and 3 caused a significant increase in this parameter, with analogue 3 even slightly exceeding melatonin. Thus, it can be concluded that analogues 1-3 are comparable to melatonin and can be utilized as potential therapeutic agents for the treatment of retinopathy of prematurity.

[The role of male factor in pregnancy loss].

Currently fertility specialists pay close attention to miscarriage. Spontaneous abortion and recurrent pregnancy loss in an early period of gestation are a frequent complication of pregnancy. Etiology of miscarriage includes genetic abnormalities, immunological disorders, endocrine abnormalities, infections and lifestyle factors. About 40% of cases of pregnancy losses remain unexplained. The role of male factor in miscarriages is considered in the review. The influence of advanced paternal ages, sperm DNA fragmentation, chromosomal abnormalities on pregnancy loss in natural conception or by assisted reproductive technique are described.

Triangle Singularity as the Origin of the a_{1}(1420).

The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a_{1}(1420), decaying to f_{0}(980)π. With a mass too close to and a width smaller than the axial-vector ground state a_{1}(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a_{1}(1260) resonance into K^{*}(→Kπ)K[over ¯] and subsequent rescattering through a triangle singularity into the coupled f_{0}(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

[Mental health assessment of medical workers during the COVID-19 pandemic in Russia: results of an online survey]. / Otsenka psikhicheskogo zdorov'ya meditsinskikh rabotnikov v period pandemii COVID-19 v Rossii (rezul'taty internet-oprosa).

OBJECTIVE: To assess the mental health of health workers during a pandemic. MATERIAL AND METHODS: Eight hundred and twelve medical workers took part in a cross-sectional Internet survey. The questionnaire included a socio-demographic block, a block of questionnaires for assessing the level of symptoms of anxiety and depression (PHQ-9 and GAD-7). The data were processed using statistical methods. RESULTS: The prevalence of anxiety and depression among healthcare providers during the pandemic was 48.77% and 57.63% respectively. Subjectively poor quality of sleep was noted by 37.4% of respondents. Cluster analysis distinguished 4 groups of respondents: group 1 was characterized by high scores on PHQ-9 and GAD-7 and a low subjective assessment of sleep quality; group 2 had low scores on PHQ-9 and GAD-7 and a high subjective assessment of sleep quality; respondents from clusters 3 and 4 had average total scores on PHQ-9 and GAD-7, however, group 4 was characterized by significantly lower values of subjective sleep quality assessment. CONCLUSION: The division into clusters makes it possible to understand which groups of medical workers require psychological (psychotherapeutic) support in the first place. Cluster 1 respondents with high levels of anxiety and depression, as well as poor sleep quality, need priority assistance.

The role of ion sources in synthesis of the super-heavy elements.

Since the early 1970s, attempts to synthesize Super Heavy Elements (SHE) have been made in many laboratories around the world. One of the main requirements of these experiments is a sufficiently large dose of target irradiation, which should be increased with a decrease in the reaction cross section. In this regard, the capacities of ion sources play an important role for the successful synthesis of SHE. At the FLNR JINR, the discovery and investigation of the new region of super heavy nuclei were based on fusion reactions of 48Ca with 238U-249Cf target nuclei. In these experiments, a technique for the production of metallic 48Ca was developed. The operation mode of the ECR ion source was set to optimize the intensity of 48Ca ions and attain maximum ionization efficiency. Because of the heaviest target for experiments on synthesis of SHE in heavy ion reactions is 249Cf, so further progress in the synthesis of elements with Z > 118 requires the production of intense beams of accelerated neutron enriched isotopes, such as 50Ti, 58Fe, and 64Ni.

Myosin IIA and formin dependent mechanosensitivity of filopodia adhesion.

Filopodia, dynamic membrane protrusions driven by polymerization of an actin filament core, can adhere to the extracellular matrix and experience both external and cell-generated pulling forces. The role of such forces in filopodia adhesion is however insufficiently understood. Here, we study filopodia induced by overexpression of myosin X, typical for cancer cells. The lifetime of such filopodia positively correlates with the presence of myosin IIA filaments at the filopodia bases. Application of pulling forces to the filopodia tips through attached fibronectin-coated laser-trapped beads results in sustained growth of the filopodia. Pharmacological inhibition or knockdown of myosin IIA abolishes the filopodia adhesion to the beads. Formin inhibitor SMIFH2, which causes detachment of actin filaments from formin molecules, produces similar effect. Thus, centripetal force generated by myosin IIA filaments at the base of filopodium and transmitted to the tip through actin core in a formin-dependent fashion is required for filopodia adhesion.

A high-power synthesized ultrawideband radiation source.

A high-power ultrawideband radiation source has been developed which is capable of synthesizing electromagnetic pulses with different frequency bands in free space. To this end, a new circuit design comprising a four-channel former of bipolar pulses of durations 2 and 3 ns has been elaborated and conditions for the stable operation of gas gaps of independent channels without external control pulses have been determined. Each element of the 2 × 2 array of combined antennas is driven from an individual channel of the pulse former. Antennas excited by pulses of the same duration are arranged diagonally. Two radiation synthesis modes have been examined: one aimed to attain ultimate field strength and the other aimed to attain an ultimate width of the radiation spectrum. The modes were changed by changing the time delay between the 2-ns and 3-ns pulses. For the first mode, radiation pulses with a frequency band of 0.2-0.8 GHz and an effective potential of 500 kV have been obtained. The synthesized radiation pulses produced in the second mode had an extended frequency band (0.1-1 GHz) and an effective potential of 220 kV. The pulse repetition frequency was 100 Hz.

First Measurement of Transverse-Spin-Dependent Azimuthal Asymmetries in the Drell-Yan Process.

The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190 GeV/c π^{-} beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3 GeV/c^{2} and 8.5 GeV/c^{2}. Within the experimental uncertainties, the observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of quantum chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was obtained at a hard scale comparable to that of these DY results. This opens the way for possible tests of fundamental QCD universality predictions.

[Role of soluble Fas ligand in myocardial remodeling, severity and outcomes of chronic heart failure]. / Rol' rastvorimogo Fas-liganda v remodelirovanii miokarda, tyazhesti techeniya i iskhodakh khronicheskoi serdechnoi nedostatochnosti.

AIM: to reveal the specific features of Fas ligand-mediated ischemic myocardial remodeling and those of chronic heart failure (CHF) development during a 12-month prospective follow-up. SUBJECTS AND METHODS: A total of 94 patients with ischemic CHF were examined and divided into 3 groups according to NYHA Functional Class (FC): 1) FC II CHF in 35 patients; 2) FC III CHF in 31; 3) FC IV CHF in 28. According to the results of the 12-month follow-up, the patients were randomized into 2 groups: A) 49 patients with a favorable course of cardiovascular disease and B) 45 patients with its poor course. Serum soluble Fas ligand (sFas-L) levels were measured by enzyme immunoassay. RESULTS: In the patients with CHF, the baseline sFas-L levels substantially exceeded that in the control group by 3-6 times (p<0.01). In the men with the poor course of CHF, the baseline serum sFAS-L levels (85.94±4.14 pg/ml) were significantly higher than that in the favorable CHF group (107.33±5.13 pg/ml; р=0.0015). ROC analysis of the sensitivity and specificity of cardiovascular risk stratification according to sFAS-L levels revealed the high prognostic value of this marker - ROC-Area±S.E. was 0.75±0.05 (95% confidence interval, 0.60 to 0.81; p=0.0005). There was a statistically significant moderate correlation of left ventricular (LV) ejection fraction with sFAS-L concentrations and a moderate direct correlation between serum sFAS-L concentrations and LV remodeling parameters. CONCLUSION: The serum level of sFas-L determines the development of ischemic LV remodeling and the severity of CHF, by increasing in proportion to the degree of disease progression. The determination of serum sFas-L levels assists in objectively estimating the severity of apoptosis and may be an important prognostic test to assess the course of CHF in patients with coronary heart disease.

[Identification and quantitative determination of baclofen in human blood by HPLC with mass spectrometry detection]. / Identifikatsiia i kolichestvennoe opredelenie baklofena v krovi metodom VÉZhKh s mass-spektrometricheskim detektirovaniem.

A method of identification and quantitative determination of baclofen in blood by HPLC with mass spectrometry detection has been developed. It is characterized by high sensitivity, specificity, linearity, accuracy, reproducibility, and a low detection for quantitative determination. The method has been used for diagnostics of acute baclofen poisoning in patients.

[Electronic textbooks and libraries abroad].

Electronic textbooks and libraries abroad. - The current article presents a brief analysis of the modern state and perspectives of electronic textbooks and libraries abroad. The material is based on the open access foreign internet sources. Using particular examples it has been shown that despite a long history of electronic textbooks and libraries development, the latter remains at the very early stage. The bureaucratic attempts to speed up this process result in costly failures. It is necessary a painstaking and cautious work in the mode of scientific practical experiment to give electronic textbooks and libraries a chance to make worthy contribution into the progress of training, education and culture.

Observation of a New Narrow Axial-Vector Meson a1(1420).

The COMPASS Collaboration at CERN has measured diffractive dissociation of 190 GeV/c pions into the π(-)π(-)π(+) final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of 3π mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow peak is observed in the f0(980)π channel with spin, parity and C-parity quantum numbers J(PC)=1(++). We present a resonance-model study of a subset of the spin-density matrix selecting 3π states with J(PC)=2(++) and 4(++) decaying into ρ(770)π and with J(PC)=1(++) decaying into f0(980)π. We identify a new a1 meson with mass (1414(-13)(+15)) MeV/c2 and width (153(-23)(+8)) MeV/c2. Within the final states investigated in our analysis, we observe the new a1(1420) decaying only into f0(980)π, suggesting its exotic nature.

[Assessment of the role of matrix metalloproteinase-3 gene polymorphism in the development of chronic heart failure].

AIM: To study the impact of a polymorphic variant of the matrix metalloproteinase-3 (MMP-3) gene on the development and course of chronic heart failure (CHF) in patients with coronary heart disease. SUBJECTS AND METHODS: A total of 277 patients with New York Heart Association (NYHA) Functional Class (FC) II-IV CHF were examined. MMP-3 -1171 5A/6A genetic polymorphism was studied by polymerase chain reaction. A control group included 136 patients (mean age 53.6 ± 4.8 years) with no signs of cardiovascular diseases, as evidenced by the examination. RESULTS: The frequency of the 5A allele and the 5A/5A genotype of the 1171 5A/6A polymorphic locus in the MMP-3 gene proved to be higher in the patients with CHF than that in the control group. Thus, the variability of the 5A allele (odds ratio (OR), 1.39; 95% confidence interval (CI): 1.033 to 1.869; p = 0.03) and the 5A/5A genotype (OR, 2.15; 95% CI: 1.131 to 4.070; p = 0.02) was associated with increased risk for CHF. There were significant differences in the frequency of MMP-3 alleles and genotypes in relation to FC of CHF. The frequency of the 5A/5A genotype was substantially higher in the patients with NYHA FC IV CHF than that in those with NYHA FC II CHF (32.8% versus 15.2%; p = 0.039). The frequency of the 5A allele was significantly higher in the patients with NYHA FC IV CHF than that in those with NYHA FC II CHF (55.5% and 39.3%; respectively; p = 0.019). Thus, the carriage of the 5A allele and the 5A/5A genotype of the 1171 5A/6A polymorphic locus in the MMP-3 gene is a risk factor of severe CHF. CONCLUSION: The determination of MMP-3 -1171 5A/6A polymorphism may be recommended for the early prediction of a risk for the development and severe course of CHF.

[Lethal intoxication with baclofen].

The objective of the present study was to select and develop simpler methods for the quantitative determination of baclofen in blood with the use of HPLC and tandem MS (MS-MS) techniques and its qualitative determination in cadaveric organs by the GC/MS technique. These mathods were shown to be suitable for the purpose of forensic medical analysis, clinical, toxicological, and therapeutic monitoring. The special emphasis is laid on the methods used to investigate the biological materials obtained from the subjects who died from baclofen intoxication.

Measurement of the charged-pion polarizability.

The COMPASS collaboration at CERN has investigated pion Compton scattering, π(-)γ→π(-)γ, at center-of-mass energy below 3.5 pion masses. The process is embedded in the reaction π(-)Ni→π(-)γNi, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q(2)<0.0015 (GeV/c)(2). From a sample of 63,000 events, the pion electric polarizability is determined to be α(π)=(2.0±0.6(stat)±0.7(syst))×10(-4) fm(3) under the assumption α(π)=-ß(π), which relates the electric and magnetic dipole polarizabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambiguously known, was performed for an independent estimate of the systematic uncertainty.

A source of high-power pulses of elliptically polarized ultrawideband radiation.

Here, we describe a source of high-power ultrawideband radiation with elliptical polarization. The source consisting of a monopolar pulse generator, a bipolar pulse former, and a helical antenna placed into a radioparent container may be used in tests for electromagnetic compatibility. In the source, the helical antenna with the number of turns N = 4 is excited with a high-voltage bipolar pulse. Preliminary, we examined helical antennas at a low-voltage source aiming to select an optimal N and to estimate a radiation center position and boundary of a far-field zone. Finally, characteristics of the source in the operating mode at a pulse repetition rate of 100 Hz are presented in the paper as well. Energy efficiency of the antenna is 0.75 at the axial ratio equal to 1.3. The effective potential of radiation of the source at the voltage amplitudes of the bipolar pulse generator equal to -175/+200 kV reaches 280 kV.

Changes in lipid metabolism during Walker 256 tumor growth and the therapeutic effect of hyperthermia.

The dynamics of lipoprotein content during Walker 256 tumor growth in rats was studied. Moderate changes in HDL and LDL were paralleled by significant changes in VLDL level. A 2-fold increase of VLDL in comparison with the intact control was recorded on day 10 of tumor growth. Exposure to total hyperthermia additionally stimulated VLDL synthesis and this parameter increased by 4 times and more in rats with tumors in comparison with controls. This effect of hyperthermia correlated with significant subsequent decrease of rat mortality caused by the lethal effect of the tumor.

[The evaluation of metastatic damage of the liver of the Wistar rats under conditions of spontaneous development of the Walker 256 carcinosarcoma].

There was held micro- and ultrastructural study of the liver of the Wistar rats in the dynamics of development of transplantable Walker 256 carcinosarcoma. The regularities of the progression of the tumor process in the form of liver metastases with appearance of intralobular metastases. In the early stages of tumor development it was marked activation of cytotoxic function of the liver with necrosis of tumor lesions accompanied by a decrease of the structural density of metastases. In advanced stages of development of the Walker 256 carcinosarcoma an estimation of parameters of tumor invasion in the liver showed an intensification of these processes with increased severity of inflammatory reactions.

A room temperature electron cyclotron resonance ion source for the DC-110 cyclotron.

The project of the DC-110 cyclotron facility to provide applied research in the nanotechnologies (track pore membranes, surface modification of materials, etc.) has been designed by the Flerov Laboratory of Nuclear Reactions of the Joint Institute for Nuclear Research (Dubna). The facility includes the isochronous cyclotron DC-110 for accelerating the intensive Ar, Kr, Xe ion beams with 2.5 MeV/nucleon fixed energy. The cyclotron is equipped with system of axial injection and ECR ion source DECRIS-5, operating at the frequency of 18 GHz. This article reviews the design and construction of DECRIS-5 ion source along with some initial commissioning results.