201 research outputs found
OPTIMAL CONTROL OF THE ALKYLATION PROCESS REACTORS
Recent studies show that one of the most important issues of static optimization of structurally complex non-stationary technological processes is the development of appropriate methods for problem decomposition. The issue of optimization of non-stationary alkylation processes and ways to solve the problems arising in this regard has been investigated in this paper. It is known that there are several ways to increase the economic efficiency of control systems for petrochemical technological processes. It includes checking of instruments and regulators, identify improvements in the control and monitor of performance, etc. One of the main ways to increase the efficiency of control systems for technological processes which depend on current conditions is to develop models and algorithms that allow control these processes in more optimal modes compared to current ones. In this regard, the presented article is relevant as it is dedicated to the development of optimal control algorithms for multistage petrochemical technological processes consisting of series-connected non-stationary technological devices
Ecological and faunal characteristics of helminths of wetland birds in North-Western Uzbekistan
The article studies some faunistic features of helminths of wetland birds in the ecological crisis zone in North-Western Uzbekistan. Parasites of wetland birds collected in the basin of the lower reaches of the Amu Darya during the hunting seasons of 2018–2022 were used as material for this work. 500 individuals of birds representing 39 species from 24 genera, 13 families and 9 orders were examined using the parasitological dissection method. The article discusses the distribution and ecology of the helminths in the studied groups of birds. A total of 112 helminth species were identified in the region – 28 species belong to the class Cestoda, the class Trematoda is represented by 57 species, Nematoda – 23 and Acanthocephala – 4 species. 92 species of heminths were identified in the study area for the first time. The work provides original data on the structure of the helminth fauna from 9 orders of wetland birds. Various paths of helminth transmission in the circulation of infection were specified. The researchers identified four ways parasites use to enter their definitive host: helminths penetrate the host’s body when the latter eats other organisms, intermediate or reservoir hosts of helminths, which are part of the definitive’s host’s diet; helminths enter the host as mechanical impurity to food or water; they make active efforts to penetrate their host; helminths are transmitted by the intermediate host when the latter forages on the definitive host. Most of intermediate hosts for representatives of the class Cestoda were crustaceans – inhabitants of different types of water bodies; Oligochaeta are also included here as second or reservoir hosts. The development of trematodes occurs with the participation of aquatic molluscs acting as the first intermediate host. Various species of insects, fish, amphibians, reptiles and small mammals were identified as the second hosts. Nematoda use a wider range of intermediate hosts (Oligochaeta, crustaceans, insects – aquatic and terrestrial). Fish and amphibians were registered as the second and reservoir hosts of nematodes. The food chains of individual orders of wetland birds largely determine the composition of helminths parasitising them and are the main factor in the formation of their helminth fauna. These processes undoubtedly occur in time and space under the strict control of environmental factors
Comparative Efficacy of Single Pill Combinations of Azilsartan Medoxomil/Chlorthalidone and Losartan/Hydrochlorothiazide in Patients with Hypertension and Heart Failure with Preserved Ejection Fraction
Aim. To study the effects of azilsartan medoxomil/chlorthalidone (AZM/CTD) and losartan/hydrochlorothiazide (LOS/HCT) combinations for NTproBNP levels, 6-minute walk test results, hydration status along with their antihypertensive efficacy according to clinical and 24-hour blood pressure in patients with hypertension and heart failure with preserved ejection fraction (HFpEF).Material and methods. An open randomized study included 56 patients with uncontrolled or untreated hypertension and HFpEF. Patients randomized to receive the AZM/CTD 40/12.5 mg/day (group 1; n=28) or LOS/HCT 100/12.5 (group 2; n=28) within 4 weeks. Patients who did not achieve the target BP <140/<90 mm Hg study drug dose was intensified: in the first group, an increase in the dose of AZM/CTD 40/25 mg/day, in the second group, an increase in the dose of LOS/HCT 100/25 mg/day. The observation period was 12 weeks. All patients underwent a clinical examination with an assessment of symptoms and/or signs of HF, laboratory and instrumental studies, including NT-proBNP, ambulatory blood pressure (BP) monitoring, applanation tonometry, a 6-minute walk test (6MWT), echocardiography. In order to assess the status of hydration, bioimpedance vector analysis (BIVA) was performed. HFpEF was diagnosed according to the HFA-PEFF algorithm. The results were considered statistically significant at p<0.05.Results. After 12 weeks, 92% of patients in the first and 78% of patients in the second group reached the target clinical BP (р<0,05). Average daily BP <130/ <80 mm Hg was reached by 82% of patients treated with the combination of AZM/CTD, compared with 67% treated with the combination of losartan/HCT (p<0.05). After 12 weeks, patients from both groups showed a significant decrease in systolic and diastolic blood pressure, central blood pressure, and a decrease in pulse wave velocity, which was more significantly significant in the first group of patients (p<0.05). During therapy in both groups of patients, a significant decrease in the level of NT-proBNP was observed: in the first group from 300 [199; 669] pg/ml to 156 [157; 448] pg/ml (p=0,003), in the second group from 298 [180; 590] pg/ml to 194 [140; 360] pg/ml (p=0,006), an increase in the distance during the 6MWT from 317 [210; 398] m to 380 [247; 455] m (p=0,006) in in the first group and an improvement in the hydration status according to the BIA data, but more significantly significant in the first group (p<0.001).Conclusion. In patients with hypertension and HFpEF, therapy with the AZM/CTD combination compared with LOS/HCT is accompanied by a more pronounced antihypertensive effect in terms of ambulatory and peripheral blood pressure, central blood pressure, NTproBNP levels, increased distance in 6MWT and achievement of euvolemia status
Analysis of production levels of InlA and InlB invasion factors in Listeria monocytogenes isolates collected in the Russian Federation
Background. Listeria monocytogenes is characterized by the presence of epidemic hypervirulent clones. A key feature of L. monocytogenes is its capacity to invade non-professional phagocytic cells. Hypervirulent clones are strongly associated with the increased production and/or the presence of certain isoforms of invasion factors InlA and InlB.
The purpose of the study is to create a test system for InlA and InlB detection and to measure the InlA and InlB production levels in L. monocytogenes isolates belonging to clonal groups with different virulence potential.
Materials and methods. The study was performed using 32 L. monocytogenes strains belonging to epidemic clones ECII, ECIV, ECVII (clonal complexes CC1, CC2, CC7) and hypovirulent clonal complex CC9. Sequencing of inlA and inlB genes was performed. The indirect enzyme-linked immunosorbent assay was used to analyze the production levels of InlA and InlB proteins.
Results. The variability of InlA was revealed among strains belonging to the same clonal complex: 3 InlA isoforms were identified among strains belonging to CC7; out of 8 strains belonging to CC9, one strain had a stop codon in the inlA gene, leading to the loss of function of the InlA protein. The differences between inlB alleles correlated with the specificity of strains belonging to a certain clonal complex. Differences in production levels of invasion factors were measured. In strains belonging to CC9, the InlA production level was 2.5 times as low compared to strains belonging to CC1, CC2, and CC7. In strains belonging to phylogenetically related CC1 and CC2, the InlB production level was on average 4 times as high compared to strains belonging to CC7 and CC9.
Conclusion. The obtained results confirm the variability of major invasion factors both among clonal complexes and strains of the same complex. The increased production of invasion factors InlA and InlB correlates with the potential virulence of strains
Integral assessment of congestion in patients with acute decompensated heart failure
Aim. To assess the prognostic value of the integral assessment using various modern methods for diagnosing congestion in patients hospitalized with acute decompensated heart failure (ADHF).Material and methods. This single-center prospective study included 165 patients with ADHF. All patients underwent a standard clinical and paraclinical examination, including assessing NT-proBNP levels, lung ultrasound B-lines, liver transient elastography, bioelectrical impedance vector analysis (BIVA) at admission and discharge. To assess clinical congestion, the Heart Failure Association consensus document scale was used. Long-term clinical outcomes were assessed by telephone survey 1, 3, 6, 12 months after discharge. As an end point, the allcause mortality and readmissions were estimated.Results. In patients hospitalized with ADHF, at discharge, differences were found in the incidence of residual congestion according to certain paraclinical methods — from 22 to 38%, subclinical — from 14,5 to 27%. When using the integral assessment of stagnation, the incidence of residual and subclinical congestion was 53,6% and 35%, respectively. Patients with residual congestion had more severe symptoms of congestion, compared with those with subclinical congestion. Patients in whom congestion was detected by 4 methods, in contrast to those by 1, 2, and 3 methods, had worse clinical and paraclinical parameters. There was a significant increase in the risk of all-cause mortality and readmission in the presence of congestion, identified by 3 (hazard ratio, 9,4 (2,2-40,6); p<0,001) and 4 methods (hazard ratio, 15,2 (3,3-68,1); p<0,001).Conclusion. For patients hospitalized with ADHF, integral assessment of residual and subclinical congestion at should be performed at discharge. The introduction of an integral assessment of congestion into routine practice will allow to identify a group of patients with more unfavorable prognostic characteristics in relation to the risk of death and readmissions, as well as to intensify drug therapy and followup at the outpatient stage
Coagulation Disorders in Infective Endocarditis: Role of Pathogens, Biomarkers, Antithrombotic Therapy (Systematic Review)
The issue of antithrombotic therapy in patients with infective endocarditis has been studied for over 75 years. During that time studying of pathogenesis of the disease and its embolic complications, lead to the introduction of the concept of “immunothrombosis”. That mechanism allows infective agents (mostly bacteria) to be cloaked from the immune system and to multiply freely, leading to growth of vegetation, thus resulting in higher chance of fragmentation. Small-scale experimental and clinical studies on the correction of hemostatic disorders in infective endocarditis, that were performed in 20th century, didn’t show any significant results, that could affect clinical practice. However, reinterpretation of available data on coagulative system will allow to have elements of hemostasis as an application point in treating infective endocarditis. The article will discuss latest insights on the role of hemostasis system in pathophysisology of infective endocarditis, its effects on the development of the embolic complications, perspectives for diagnostics and treatment
Application of Headspace Solid-Phase Microextraction for Determination of Chloro-Organic Compounds in Sewage Samples
Solid phase microextraction (SPME) has been optimized and applied to the determination of the volatile halogenated compounds (VHCs) and semi-volatile halogenated compounds (SVHCs). Three types of SPME fiber coated with different stationary phases (PDMS–100 μm, CAR/PDMS-75 μm, PDMS/DVB–65 μm) were used to examine their extraction efficiencies for the compounds tested. Experimental parameters such as the selection of SPME coatings, extraction time, and addition of salts were studied. The carboxen-polydimethylsiloxane (CAR/PDMS) fiber appears to be the most suitable for the determination of VHCs. Analytical parameters such as linearity, limit of detection, and precision were also evaluated. Application of ECD detector for the determination of VHCs and SVHCs allows their determination on the low concentration level, ranging from 0.005 to 0.8 μg/L−1. The HS-SPME-GC/ECD procedure gave good analytical precision expressed as relative standard deviation (RSD) (ranged from 5.08% to 8.07%) for a concentration level of 5 μg/L−1 and good linearity (r2 > 0.98) in a wide calibration range. The applied HS-SPME-GC/ECD method was found to be a quick and effective technique for the determination of microtrace amounts of volatile and semi-volatile halogenated compounds in samples containing high amounts of various organic compounds
Lenvatinib Therapy in Patients with Unresectable Hepatocellular Carcinoma in Real Clinical Practice
Aim. To determine lenvatinib treatment outcomes in patients with advanced unresectable hepatocellular carcinoma (uHCC) in real clinical practice.Patients and methods. A multicenter retrospective observational study included 58 patients with a confirmed uHCC diagnosis receiving lenvatinib. At baseline, ECOG, Child-Pugh and BCLC scores were assessed. The objective response rate (ORR), disease control rate (DCR), median overall survival (OS) and median progression-free survival (PFS) rates were assessed. In addition, adverse effects (AE) during treatment were monitored.Results. The median OS and PFS comprised 14.6 (95 % CI 10.6–18.6) and 11.1 months (95 % CI 8.31–13.8), respectively. The ORR amounted to 32.8 %, while DCR reached the level of 79.3 %. The levels of ORR and DCR were not statistically significantly different between the patients with stages B and C according to the BCLC staging system, with grades 0 and 1 according to ECOG, with classes A and B according to the Child-Pugh score, with viral and non-viral HCC etiology, with and without extrahepatic spread, and with and without portal vein invasion. Patients with alpha-fetoprotein (AFP) blood levels <200 ng/mL showed significantly higher ORR and DCR compared to those with AFP levels >200 ng/mL (44.4 % vs. 13.6 %, p = 0.015; and 88.9 % vs. 63.6 %, p = 0.021, respectively). The uHCC stage according to BCLC, ECOG functional status, Child-Pugh class, presence or absence of extrahepatic spread and viral etiology had no effect on the OS and PFS median levels. Patients with macroscopic portal vein invasion had a significantly lower PFS compared with those lacking this complication: 3.97 (0.00-8.07) vs. 11.1 (8.46-13.7), p = 0.053. AFP levels ≥200 ng/mL adversely affected survival rates: median OS comprised 12.0 (5.95-18.9) months in the group of patients with AFP ≥200 ng/mL vs. 16.1 (8.73-23.5) months in the group of patients having AFP <200 ng/mL, p = 0.020. AEs were registered in 81.0% (n = 47) of patients. Among the most common AEs were arterial hypertension (32.8 %), weakness (24.1 %), weight loss (12.1 %) and appetite loss (10.3 %). Due to AEs, Lenvatinib was withdrawn in 5 (8.6 %) patients.Conclusion. Lenvatinib confirmed its efficacy and safety in patients with uHCC in real clinical practice. The treatment outcome might be affected by AFP levels and the presence of macroscopic portal vein invasion. Further comparative studies into treatment regimens applied in real clinical practice are required
ВЛИЯНИЕ 1%-НОГО РАСТВОРА ЦИФЛУТРИНА НА РЕПРОДУКТИВНУЮ ФУНКЦИЮ БЕЛЫХ КРЫС
The influence of 1 % solution of cyfluthrin on reproductive function of rats is studied. The drug in a dose of 1/5 from LD50 during 10 weeks didn’t influence on fecundity, reproductive function and postnatal development of posterity.Изучено влияние препарата на основе цифлутрина на репродуктивную систему белых крыс. Препарат при нанесении на кожу животных в дозе 1/5 от ЛД50 в течение 10 недель не оказывает влияния на плодовитость, репродуктивную функцию и постнатальное развитие крысят
Intima-media thickness at the near or far wall of the common carotid artery in cardiovascular risk assessment
Aims: Current guidelines recommend measuring carotid intima-media thickness (IMT) at the far wall of the common carotid artery (CCA). We aimed to precisely quantify associations of near vs. far wall CCA-IMT with the risk for atherosclerotic cardiovascular disease (CVD, defined as coronary heart disease or stroke) and their added predictive values.
Methods and results: We analysed individual records of 41 941 participants from 16 prospective studies in the Proof-ATHERO consortium {mean age 61 years [standard deviation (SD) = 11]; 53% female; 16% prior CVD}. Mean baseline values of near and far wall CCA-IMT were 0.83 (SD = 0.28) and 0.82 (SD = 0.27) mm, differed by a mean of 0.02 mm (95% limits of agreement: −0.40 to 0.43), and were moderately correlated [r = 0.44; 95% confidence interval (CI): 0.39–0.49). Over a median follow-up of 9.3 years, we recorded 10 423 CVD events. We pooled study-specific hazard ratios for CVD using random-effects meta-analysis. Near and far wall CCA-IMT values were approximately linearly associated with CVD risk. The respective hazard ratios per SD higher value were 1.18 (95% CI: 1.14–1.22; I² = 30.7%) and 1.20 (1.18–1.23; I² = 5.3%) when adjusted for age, sex, and prior CVD and 1.09 (1.07–1.12; I² = 8.4%) and 1.14 (1.12–1.16; I²=1.3%) upon multivariable adjustment (all P < 0.001). Assessing CCA-IMT at both walls provided a greater C-index improvement than assessing CCA-IMT at one wall only [+0.0046 vs. +0.0023 for near (P < 0.001), +0.0037 for far wall (P = 0.006)].
Conclusions: The associations of near and far wall CCA-IMT with incident CVD were positive, approximately linear, and similarly strong. Improvement in risk discrimination was highest when CCA-IMT was measured at both walls
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