378 research outputs found
Possibilities of Detecting Pre-clinical Forms of Atherosclerosis During Periodic Preventive Inspections in Organized Collectives at Workers of Machine Building Enterprises
Aim. To study the structural and functional features of the carotid and femoral arteries using ultrasound duplex scanning of them in patients with hypertension undergoing periodic preventive medical examination.Material and methods. Periodic preventive examination was carried out for 2431 employees (1311 men and 1120 women) aged 20-65 years using a specially developed questionnaire, blood pressure measurement, anthropometry, total cholesterol test. Hypertensive men were assessed for preclinical manifestations of atherosclerosis by ultrasound duplex scanning of the carotid and femoral arteries.Results. Hypertensive men (BP ≥140/90 mmHg and/or taking antihypertensive drugs; n=176, mean age 43.5 years) were included in the study. An increase in the thickness of the intima-media complex in the carotid arteries was found in 22.2% (n=38) people, in the femoral arteries – in 34.1% (n=60) people, in both basins – in 16.5% (n= 29) man. Atherosclerotic plaques in the carotid arteries were found in 40.3% of people (n=71), and in the femoral arteries – in 34.7% (n=61) of people, in both pools – in 23.9% (n=42) of men.Conclusion. Ultrasound diagnostic using modern ultrasound scanners is a highly informative method for non-invasive diagnosis of atherosclerosis in the arteries of the carotid and femoral basins in employees of a large industrial enterprise with arterial hypertension in the conditions of the medical and sanitary department. Carrying out these diagnostic approaches is advisable when organizing periodic medical examinations in order to improve primary prevention, as well as to prevent the aggravation of the identified pathological process, reduce complications, improve quality and increase life expectancy
Non-natural nucleosides based on 1,2,4-triazolo[5,1-c][1,2,4]triazin-4(6H)- ones
Two regioselective methods for the synthesis of nucleosides in the series of 3-phenyl- and 3- ethoxycarbonyl-1,2,4-triazolo[5,1-c][1,2,4]triazin-4-ones were developed. The first route involves a Vorbrüggen glycosylation reaction. The second one is based on condensation of 1,2,4- triazolo[5,1-c][1,2, 4]triazin-4-one sodium salts with protected 1-bromo-sugar derivatives
A Numerical Model of an Electrostatic Precipitator
This paper presents a Computational Fluid Dynamics (CFD) model for a wire-plate electrostatic precipitator (ESP). The turbulent gas flow and the particle motion under electrostatic forces are modelled using the CFD code FLUENT. Numerical calculations for the gas flow are carried out by solving the Reynolds-averaged Navier-Stokes equations and turbulence is modelled using the k-ε turbulence model. An additional source term is added to the gas flow equation to capture the effect of electric field. This additional source term is obtained by solving a coupled system of the electric field and charge transport equations. The particle phase is simulated by using Discrete Phase Model (DPM). The results of the simulation are presented showing the particle trajectory inside the ESP under the influence of both aerodynamic and electrostatic forces. The simulated results have been validated by the established data. The model developed is useful to gain insight into the particle collection phenomena that takes place inside an industrial ESP
Synthesis of acyclic nucleoside analogues by one-step Vorbrüggen glyco-sylation of 1,2,4-triazolo[1,5-a]pyrimidine-7-ones
New analogues of acyclovir have been prepared by reacting 1,2,4 -triazolo[1,5-a]pyrimidin-7-ones 1а-i and (2-acetoxyethoxy)methyl acetate 2 in the presence of trimethylsilyl trifluoromethanesulfonate as a catalyst. The interaction between the compounds 1а-е and 2 has led to a mixture of N3 and N4 isomers. In contrast, the reaction of compounds 1g-i and 2 proceeded selectively to form N3 isomers. In the case of compounds 1a-c the predominant product is the one with the acyclic moiety in azine ring (N4 isomer). Interaction between 1d-f and 2 has led to mixtures comprising mainly N3 isomer. It has been found that the ratio of glycosylation products 1 and 2 are thermodynamically controlled. The structure of the obtained compounds has been proved by 1Н, 13С, two-dimensional 1Н-13С NMR spectroscopy and X-ray analysis
Influence of various parameters on the vegetable raw material pelleting process and pellets quality (review)
Determining the regularities of the process of pelleting vegetable raw materials is relevant for the improvement of technologies and technical equipment in order to reduce energy intensity and improve the quality of pellets. The generalization of the results of the research aimed at studying the influence of various parameters on the process of pelleting vegetable raw materials and the quality of feed and biofuel pellets is the purpose of the research. A selection and systematic review of the scientific literature on the subject of the study for the period of 2007-2022 has been carried out. The analysis has proved that heat pre-treatment and moistening of vegetable raw materials, as well as their composition and particle size are the factors that have the greatest impact on the quality of feed and biofuel pellets. Increasing the pressure in the range of 20...200 MPa results in increasing the pellets durability. A die temperature of around 100°C is optimum for obtaining dense pellets of highquality from vegetable raw materials. The design parameters of the pelletizer play an important role in obtaining high-quality pellets when processing vegetable raw materials. The design of the inlet in the form of a tapering cone helps to reduce energy consumption and pelleting pressure. An increase in the ratio of the die channel length to its diameter exponentially increases the pelleting pressure and its energy intensity. The interplay between the physical processes occurring in the pelletizer makes it difficult to interpret the impact of each parameter on the pelleting process, so different authors have different assessments of the contribution of individual factors in producing high-quality pellets. Therefore, the interaction between the individual pelleting parameters and their influence on the results of the process should be examined more precisely
Long-range 1H-15N J couplings providing a method for direct studies of the structure and azide-tetrazole equilibrium in a series of azido-1,2,4-triazines and azidopyrimidines
The selectively 15N labeled azido-1,2,4-triazine 2*A and azidopyrimidine 4*A were synthesized by treating hydrazinoazines with 15N-labeled nitrous acid. The synthesized compounds were studied by 1H, 13C, and 15N NMR spectroscopy in DMSO, TFA, and DMSO/TFA solutions, where the azide-tetrazole equilibrium could lead to the formation of two tetrazoles (T, T′) and one azide (A) isomer for each compound. The incorporation of the 15N label led to the appearance of long-range 1H-15N coupling constants (JHN), which can be measured easily by using amplitude-modulated 1D 1H spin-echo experiments with selective inversion of the 15N nuclei. The observed JHN patterns enable the unambiguous determination of the mode of fusion between the azole and azine rings in the two groups of tetrazole isomers (2*T′, 4*T′ and 2*T, 4*T), even for minor isoforms with a low concentration in solution. However, the azide isomers (2*A and 4*A) are characterized by the absence of detectable J HN coupling. The analysis of the JHN couplings in 15N-labeled compounds provides a simple and efficient method for direct NMR studies of the azide-tetrazole equilibrium in solution. © 2013 American Chemical Society
Spin-spin coupling constants 13C-15N and 1H-15N in the investigation of azido-tetrazole tautomerism in a series of 2-azidopyrimidines
A new method was developed for the investigation of an azido-tetrazole equilibrium based on using a complex analysis of 13C-15N and 1H-15N spin-spin coupling constants. The use of this approach became possible due to the selective inclusion of 15N isotopes into the structures of 2-azidopyrimidines and their cyclic analogs tetrazolo[1,5-a]pyrimidines. © 2013 Springer Science+Business Media New York
THERAPEUTIC EQUIVALENCE OF ORIGINAL CLOPIDOGREL (PLAVIX) AND ITS GENERIC (EGITROMB). RESULTS OF COMPARATIVE RANDOMIZED CROSS-OVER BLIND STUDY
Aim. To study therapeutic equivalence (efficacy, safety and tolerability) of original clopidogrel (Plavix) and its generic (Egitromb) in patients of high cardiovascular risk. Material and methods. Thirty one patients with coronary heart disease and indications for clopidogrel therapy were involved into the randomized cross-over blind study. Half of the patients received original clopidogrel (75 mg daily) during the first 2 weeks and then they received generic clopidogrel in the same dose during next 2 weeks. Another half of the patients received the drugs in reverse order. Antiplatelet activity of Plavix and Egitromb was estimated by effects on ADP-induced platelet aggregation initially and after 2 weeks of treatment with each drug. Study blinding was provided by the following approach: doctors of cardiology clinic performed clinical monitoring and drug distribution; coded blood samples for platelet aggregation assessment were studied in independent laboratory of thrombosis; statistical data analysis was performed by biostatistics expert in other research center. Results. 2-week therapy with each drug led to a significant decrease of ADP-induced platelet aggregation which remained low after switching from original drug to generic and vice versa. Aggregation dynamics did not depend on the first administered drug. There were no significant differences between aggregation changes as a result of treatment with original or generic drug. No one adverse event was observed in association with both drugs therapy. Conclusion. Generic drug Egitromb (Egis, Hungary) and original clopidogrel Plavix (Sanofi-Aventis, France) have equivalent antiplatelet effect
PHARMACOECONOMIC ANALYSIS OF CARVEDILOL THERAPY IN PATIENTS WITH ARTERIAL HYPERTENSION AND METABOLIC RISK FACTORS (ACCORDING TO THE CAMELLIA STUDY)
Aim. To perform cost-effectiveness analysis of 24 weeks antihypertensive therapy based on carvedilol or metoprolol in patients with arterial hypertension (HT) 1-2 degrees and overweight/obesity. To assess effects of carvedilol therapy on 10-year expected risk of cardiovascular complications (CVC).Material and methods. Patients with HT and overweight/obesity (n=320) were included into the study and randomly split in two groups. Patients of the first group (n=160) received carvedilol as a basic therapy and patients of the second group (n=160) — metoprolol. Both groups of the patients were comparable on key clinical characteristics.Results. In 24 weeks of treatment systolic and diastolic blood pressure (BP) decreased significantly in comparison with the baseline level (p<0.0001). Dose doubling of beta-blockers was required more often in patients treated with carvedilol. At the same time a combined antihypertensive therapy of the patients treated with carvedilol was required less (p>0.05). Target BP levels were achieved in carvedilol and metoprolol groups in 96.2and 95.5% of patients respectively (p=0.85). Carvedilol had better effect on plasma metabolic indicators such as glucose (p<0.01), lipid profile, uric acid level. Reduction in expected 10-year risk of death was more pronounced in 24 weeks carvedilol treatment. Cost of target BP level achievement was approximately 2.5 times higher in carvedilol group than this in metoprolol group. However cost of additional therapy was higher in metoprolol group. 1% reduction of the 10-year expected risk of CVC death cost 1 847 rubles in carvedilol therapy.Conclusion. Carvedilol therapy (vs metoprolol one) has a higher cost under comparable efficacy. Additional expenses are compensated with the favorable effect on metabolic indices and a more pronounced effect on reduction in the 10-year expected risk of CCO death. That is why carvedilol can be recommended to patients with HT and metabolic risk factors. Longer studies are necessary to assess an effect of carvedilol therapy on prognosis in patients with HT and concomitant metabolic disorders
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