Exposure to lead is associated with an increased risk of cardiovascular diseases. Outbred white male rats were injected with lead acetate intraperitoneally three times a week and/or were forced to ...run at a speed of 25 m/min for 10 min 5 days a week. We performed noninvasive recording of arterial pressure, electrocardiogram and breathing parameters, and assessed some biochemical characteristics. Electrophoresis in polyacrylamide gel was used to determine the ratio of myosin heavy chains. An in vitro motility assay was employed to measure the sliding velocity of regulated thin filaments on myosin. Isolated multicellular preparations of the right ventricle myocardium were used to study contractility in isometric and physiological modes of contraction. Exercise under lead intoxication normalized the level of calcium and activity of the angiotensin-converting enzyme in the blood serum, normalized the isoelectric line voltage and T-wave amplitude on the electrocardiogram, increased the level of creatine kinase-MB and reduced the inspiratory rate. Additionally, the maximum sliding velocity and the myosin heavy chain ratio were partly normalized. The effect of exercise under lead intoxication on myocardial contractility was found to be variable. In toto, muscular loading was found to attenuate the effects of lead intoxication, as judged by the indicators of the cardiovascular system.
The memory effect in the form of hysteresis has been detected in the measured dependence of the intensity of the photon echo in YLiF
4
and LuLiF
4
samples with Er
3+
impurity ions on the orientation, ...strength, and variation direction of the magnetic field. The prehistory of the location of a sample in the magnetic field with a certain direction and strength is written and stored for no less than 6 h at a temperature of 2 K. The effect crucially depends on the orientation of the optical axis of the sample with respect to the external magnetic field.
Subchronic intoxication was induced in outbred male rats by repeated intraperitoneal injections with lead oxide (PbO) and/or cadmium oxide (CdO) nanoparticles (NPs) 3 times a week during 6 weeks for ...the purpose of examining its effects on the contractile characteristics of isolated right ventricle trabeculae and papillary muscles in isometric and afterload contractions. Isolated and combined intoxication with these NPs was observed to reduce the mechanical work produced by both types of myocardial preparation. Using the in vitro motility assay, we showed that the sliding velocity of regulated thin filaments drops under both isolated and combined intoxication with CdO-NP and PbO-NP. These results correlate with a shift in the expression of myosin heavy chain (MHC) isoforms towards slowly cycling β-MHC. The type of CdO-NP + PbO-NP combined cardiotoxicity depends on the effect of the toxic impact, the extent of this effect, the ratio of toxicant doses, and the degree of stretching of cardiomyocytes and muscle type studied. Some indices of combined Pb-NP and CdO-NP cardiotoxicity and general toxicity (genotoxicity included) became fully or partly normalized if intoxication developed against background administration of a bioprotective complex.
K+Λ(1405) photoproduction has been studied at the BGOOD experiment via the all neutral decay, Λ(1405)→Σ0π0. The unique BGOOD experimental setup allows both the cross section and Λ(1405) invariant ...mass distribution (line shape) to be measured over a broad K+ polar angle range, extending to extreme forward K+ angles unattainable at previous experiments.
Evidence is provided for the role of a triangle singularity driven by the N⁎(2030) resonance, which appears to contribute significantly to K+Λ(1405) photoproduction. This is observed in the integrated cross section which was determined with unprecedented energy resolution and supported by the angular distributions. The measured line shape is also in agreement with the previous results of CLAS and ANKE, and is consistent with two poles derived in χPT based models.
The coherent reaction, γd→π0π0d was studied with the BGOOD experiment at ELSA from threshold to a centre-of-mass energy of 2850MeV. A full kinematic reconstruction was made, with final state ...deuterons identified in the forward spectrometer and π0 decays in the central BGO Rugby Ball. The strength of the differential cross section exceeds what can be described by models of coherent photoproduction and instead supports the three isoscalar dibaryon candidates reported by the ELPH collaboration at 2.38, 2.47 and 2.63GeV/c2. A low mass enhancement in the π0π0 invariant mass is also observed at the d⁎(2380) centre-of-mass energy which is consistent with the ABC effect. At higher centre-of-mass energies, a narrow peak in the π0d invariant mass at 2114MeV/c2 with a width of 20MeV/c2 supports a sequential two-dibaryon decay mechanism.
γ
p
→
K
+
Λ
differential cross sections and recoil polarisation data from threshold for extremely forward angles are presented. The measurements were performed at the BGOOD experiment at ELSA, ...utilising the high angular and momentum resolution forward spectrometer for charged particle identification. The high statistics and forward angle acceptance enables the extraction of the cross section as the minimum momentum transfer to the recoiling hyperon is approached.
The paper discusses the results of applying the methods of correlation-regression analysis and fuzzy logic for analyzing the statistical information of industrial injury rates in the Udmurt Republic, ...and shows the stages of modeling. Correlation-regression analysis was carried out using the MS Office Excel "Data Analysis" package; processing by the Mamdani algorithm (fuzzy logic) was carried out in the Mathlab environment. For the number of workers injured with further disability per 1 working day or more and fatal outcome in the Udmurt Republic, the results of using both methods are shown. Recommendations are given on the application of a particular method in the practical activities of managing the labor protection of organizations as a whole, by type of economic activity or constituent entity of the federation. Recommendations are provided, the implementation of which will improve the accuracy and efficiency of the analysis of industrial injuries by the considered methods.
The γp→K+Σ0 differential cross section at extremely forward angles was measured at the BGOOD experiment. A three-quarter drop in strength over a narrow range in energy and a strong dependence on the ...polar angle of the K+ in the centre-of-mass of the reaction is observed at a centre-of-mass energy of 1900 MeV. Residing close to multiple open and hidden strangeness thresholds, the structure appears consistent with meson-baryon threshold effects which may contribute to the reaction mechanism.
The state, problems, and prospects of conventional, unified and special laboratory, bench and full-scale tests to substantiate the systematic assessment of strength, durability, survivability, cold ...resistance, reliability, and safety of the key elements of pipeline transport of crude oil and refined products are considered. These tests correlate with the stages of the pipeline life cycles and basic and reference computational-experimental methods of determining the criterial characteristics of pipe steels, pipes and main pipelines with regard to domestic and foreign practices. The experimental basic mechanical characteristics obtained in standard static tensile tests (yield and strength limits, elastic moduli) are part of the basic static strength calculations of newly designed and operating pipelines. Standard hardness and impact elasticity tests are used to control the pipe steel quality. The results of standard tensile tests provide additional design information for the assessment of static strength with respect to the ductility and degree of steel hardening during elastoplastic deformation. Unified laboratory tests are meant for refining the pipeline strength with allowance for the stress state 3D effects, absolute sizes of the pipeline cross section, strain rate, anisotropy, cold resistance, corrosion, and the presence of welded joints. The assessment of pipe steel crack resistance and pipes according to the criteria of linear and nonlinear fracture mechanics with allowance for technological and operational defects holds a specific place in laboratory and bench testing. The experience in conducting these tests, accumulated in the Russian oil pipeline system is considered.
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