209 research outputs found

    МЕТОДИЧНІ ПИТАННЯ ДОСЛІДЖЕННЯ БУТИЛЬОВАНИХ МІНЕРАЛЬНИХ ВОД

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    The paper suggests a new indicator of natural water quality a coefficient of identification as a slope of the relationship inverse electrical conductivity from degree of research water dilution by distilled water to establish the fact that bottled drinking and mineral waters do not comply with normative requirements. An example is given for the identification of tap water among 10 trademarks of bottled drinking water.Запропоновано новий показник якості природних вод для встановлення факту невідповідності бутильованих питних і мінеральних вод нормативним вимогам коефіцієнт ідентифікації як тангенс кута нахилу залежності оберненої електропровідності від ступеня розведення дослідженої води водою дистильованою. Показано приклад ідентифікації водогінної води серед 10 брендів бутильованих питних вод

    Effectiveness of Class IC Antiarrhythmics in Patients with Paroxysmal Form of Atrial Fibrillation in Absence of Structural Heart Disease

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    Aim. To study the efficacy of class IC arrhythmic drugs (AAD) and catheter ablation (CA) for paroxysmal form of atrial fibrillation (AF) in patients with without structural heart disease.Material and methods. The study included 122 patients (44 men, 78 women, mean age 63 [55;68] years) with symptomatic AF paroxysms. Patients was divided into the lappaconitine hydrobromide group (LH group; n=26), the propafenone group (P group; n=25) – 25 patients, the diethylaminopropionylethoxycarbonylaminophenothiazine hydrochloride (DH group; n=23), the CA groups: radiofrequency ablation (RFA group; n=24) and cryoballoon ablation (CRYO group; n=24) groups each included 24 patients. The primary endpoint was the AF recurrence within 6 and 12 months from the onset of antiarrhythmic drug therapyand in RFA and CRYO groups – within 6 and 12 months after the end of the blinding period. Additionally, in AAD groups a composite endpoint was assessed: the frequency of recurrence of AF within 6 months and the frequency of side effects requiring drug withdrawal.Results. Within the 6 months AF recurrence was observed in 13 (50%) patients of the LH group, 11 (44%) patients of the P group, and 13 (56.5%) patients of the DH group (p=0.687). Side effects requiring drug withdrawal were observed in the LH group in 2 patients (7.7%), in the P group in 3 patients (12%) and in the DH group in 3 patients (13%) (p=0.801). The difference in frequency of reaching the composite endpoint was not significant (p = 0.581) and the incidence was 57.7%, 56%, 69.5%, respectively in groups LH, P and DH. The efficacy of CA was higher than class IC AADs: 77% vs 39% (that including the withdrawals of AADs due to side effects) (p˂0.001). At the same time, there was no significant difference in the effectiveness of RFA and CRYO: AF recurrences within 6 months after the end of the blinding period were registered in the RFA group in 29% of cases, in the CRYO group – in 16.7% of cases (p=0.247). The overall effectiveness of CA after 12 months was 69%, which was significantly higher than the effectiveness of AADs that was 38% (p˂0.001).Conclusion. Starting the AAD therapy with IC class in patients with paroxysmal AF in the absence of structural pathology, despite acceptable safety, one should take into account that, regardless of the initially prescribed drug, less than half of patients can achieve prevention of AF recurrence within 1 year. CA for AF can be considered as a first line therapy or can be recommended if one of IC class AADs is ineffective

    BIOMECHANICAL REMODELING OF BIODEGRADABLE SMALL-DIAMETER VASCULAR GRAFTS IN SITU

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    Aim: to evaluate the biomechanical remodeling of polymer grafts modified with vascular endothelial growth factor (VEGF) after implantation into rat abdominal aorta.Materials and methods. Vascular grafts of2 mmdiameter were fabricated by electrospinning from polycaprolactone (PCL) and a mixture of poly (3-hydroxybutyrate-co-3-hydroxyvalerate) and PCL. The grafts were modified with VEGF by biphasic electrospinning. Morphology of the grafts was assessed by scanning electron microscopy. Physico-mechanical properties of PCL and PHBV/PCL grafts were estimated using uniaxial tensile test and physiological circulating system equipped with state-of-theart ultrasound vascular wall tracking system. Physico-mechanical testing of PCL/VEGF and PHBV/PCL/VEGF was performed before and after implantation into rat abdominal aorta for 6 months. The modeling of coronary artery bypass grafting (CABG) was performed by finite element analysis for modified grafts.Results. Durability of PCL and PHBV/PCL grafts did not differ from that of human internal mammary artery; however, elasticity and stiffness of these grafts were higher compared to internal mammary artery. Viscoelastic properties of the grafts were comparable to those of native blood vessels. Modification of the grafts with VEGF reduced material stiffness. Six months postimplantation, PCL/VEGF and PHBV/PCL/VEGF were integrated with aortic tissue that induced changes in the physico-mechanical properties of the grafts similar to the native vessel. Biomechanical modeling confirmed the functioning of modified grafts in bypass position for CABG.Conclusion. PCL/VEGF and PHBV/PCL/VEGF grafts have satisfactory physico-mechanical properties and can be potentially used in the reconstruction of blood vessels

    Studies of new Higgs boson interactions through nonresonant HH production in the b¯bγγ fnal state in pp collisions at √s = 13 TeV with the ATLAS detector

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    A search for nonresonant Higgs boson pair production in the b ¯bγγ fnal state is performed using 140 fb−1 of proton-proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. This analysis supersedes and expands upon the previous nonresonant ATLAS results in this fnal state based on the same data sample. The analysis strategy is optimised to probe anomalous values not only of the Higgs (H) boson self-coupling modifer κλ but also of the quartic HHV V (V = W, Z) coupling modifer κ2V . No signifcant excess above the expected background from Standard Model processes is observed. An observed upper limit µHH < 4.0 is set at 95% confdence level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The 95% confdence intervals for the coupling modifers are −1.4 < κλ < 6.9 and −0.5 < κ2V < 2.7, assuming all other Higgs boson couplings except the one under study are fxed to the Standard Model predictions. The results are interpreted in the Standard Model efective feld theory and Higgs efective feld theory frameworks in terms of constraints on the couplings of anomalous Higgs boson (self-)interactions

    Measurement of the H → γ γ and H → ZZ∗ → 4 cross-sections in pp collisions at √s = 13.6 TeV with the ATLAS detector

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    The inclusive Higgs boson production cross section is measured in the di-photon and the Z Z∗ → 4 decay channels using 31.4 and 29.0 fb−1 of pp collision data respectively, collected with the ATLAS detector at a centre of-mass energy of √s = 13.6 TeV. To reduce the model dependence, the measurement in each channel is restricted to a particle-level phase space that closely matches the chan nel’s detector-level kinematic selection, and it is corrected for detector effects. These measured fiducial cross-sections are σfid,γ γ = 76+14 −13 fb, and σfid,4 = 2.80 ± 0.74 fb, in agreement with the corresponding Standard Model predic tions of 67.6±3.7 fb and 3.67±0.19 fb. Assuming Standard Model acceptances and branching fractions for the two chan nels, the fiducial measurements are extrapolated to the full phase space yielding total cross-sections of σ (pp → H) = 67+12 −11 pb and 46±12 pb at 13.6 TeV from the di-photon and Z Z∗ → 4 measurements respectively. The two measure ments are combined into a total cross-section measurement of σ (pp → H) = 58.2±8.7 pb, to be compared with the Stan dard Model prediction of σ (pp → H)SM = 59.9 ± 2.6 p

    Measurement of the cross-sections of the electroweak and total production of a Zγ pair in association with two jets in pp collisions at root s=13 TeV with the ATLAS detector

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    Combination of searches for heavy spin-1 resonances using 139 fb−1 of proton-proton collision data at s = 13 TeV with the ATLAS detector

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    A combination of searches for new heavy spin-1 resonances decaying into different pairings of W, Z, or Higgs bosons, as well as directly into leptons or quarks, is presented. The data sample used corresponds to 139 fb−1 of proton-proton collisions at = 13 TeV collected during 2015–2018 with the ATLAS detector at the CERN Large Hadron Collider. Analyses selecting quark pairs (qq, bb, , and tb) or third-generation leptons (τν and ττ) are included in this kind of combination for the first time. A simplified model predicting a spin-1 heavy vector-boson triplet is used. Cross-section limits are set at the 95% confidence level and are compared with predictions for the benchmark model. These limits are also expressed in terms of constraints on couplings of the heavy vector-boson triplet to quarks, leptons, and the Higgs boson. The complementarity of the various analyses increases the sensitivity to new physics, and the resulting constraints are stronger than those from any individual analysis considered. The data exclude a heavy vector-boson triplet with mass below 5.8 TeV in a weakly coupled scenario, below 4.4 TeV in a strongly coupled scenario, and up to 1.5 TeV in the case of production via vector-boson fusion

    Measurement and interpretation of same-sign W boson pair production in association with two jets in pp collisions at s = 13 TeV with the ATLAS detector

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    This paper presents the measurement of fducial and diferential cross sections for both the inclusive and electroweak production of a same-sign W-boson pair in association with two jets (W±W±jj) using 139 fb−1 of proton-proton collision data recorded at a centre-of-mass energy of √s = 13 TeV by the ATLAS detector at the Large Hadron Collider. The analysis is performed by selecting two same-charge leptons, electron or muon, and at least two jets with large invariant mass and a large rapidity diference. The measured fducial cross sections for electroweak and inclusive W±W±jj production are 2.92 ± 0.22 (stat.) ± 0.19 (syst.)fb and 3.38±0.22 (stat.)±0.19 (syst.)fb, respectively, in agreement with Standard Model predictions. The measurements are used to constrain anomalous quartic gauge couplings by extracting 95% confdence level intervals on dimension-8 operators. A search for doubly charged Higgs bosons H±± that are produced in vector-boson fusion processes and decay into a same-sign W boson pair is performed. The largest deviation from the Standard Model occurs for an H±± mass near 450 GeV, with a global signifcance of 2.5 standard deviations
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