11 research outputs found
Production of facing ceramic material using cullet
The research presents experimental results concerning the charge composition development for ceramics, used for cladding facades and basements of buildings and structures. The given composition is suggested to be based on the low plasticity clay as a basic component, which cannot be used to produce crackless, durable and frost resistant ceramics without introducing functional additives. The following functional additives were applied in the conducted experiments: boric acid, used as a fuse for the reduction of liquid phase sintering temperature and the increase of vitreous phase amount; various empties cullet, used as a fluxing and strengthening additive, which is the source of vitreous phase, forming the rigid frame of interconnected ceramic particles through a layer of vitreous phase. The research experiments stated that the highest compressive strength and frost resistance and the least water absorption can be achieved when 30 wt. % of colorless empties cullet and 2,5 wt.% of boric acid are introduced into the charge. Besides the research demonstrates the results of determining the dependence of bending strength, density, thermal conductivity, open and total porosity. The developed charge composition on the one hand stipulates the solution environmental and technical-economic problems of natural resources rational use and waste management, and on the other hand allows producing high quality facing ceramic products at a reduced cost and using low demand resources
Bergmeier, Roland: Die Qumran-Essener Hypothese. Die Handschriftenfunde von Qumran, ihr spezifischer Trägrkreis und die essensische Gemeinschaftsbewegung (Biblisch-Theologische Studien, Bd. 133), Neukirchen-Vluyn: Neukirchner Verlag 2013, 267 S.)
Eine Rezension einer wichtigen Arbeit zu Verbindungen zwischen den Qumranschriften und der jĂĽdisch-hellenistischen Literatur
Paul von Geldern - ein Wiener Universitätstheologe aus dem Ende des 14. Jahrhunderts. Zur Handschrift 20173 der Collectio Amploniana zu Erfurt
Bergmeier, Roland: Die Qumran-Essener Hypothese. Die Handschriftenfunde von Qumran, ihr spezifischer Trägrkreis und die essensische Gemeinschaftsbewegung (Biblisch-Theologische Studien, Bd. 133), Neukirchen-Vluyn: Neukirchner Verlag 2013, 267 S.)
Eine Rezension einer wichtigen Arbeit zu Verbindungen zwischen den Qumranschriften und der jĂĽdisch-hellenistischen Literatur
Das Leben des Weisen. Philon von Alexandria, De Abrahamo, herausgegeben von Daniel Lanzinger
Predictors of Mortality Following Aortic Valve Replacement in Aortic Stenosis Patients
Background: Understanding of the risk factors for the development of adverse outcomes after aortic valve replacement is necessary to develop timely preventive measures and to improve the results of surgical treatment. Methods: We analyzed patients with aortic stenosis (n = 742) who underwent surgical treatment in the period 2014–2020. The average age was 63 (57;69) years—men 58%, women 42%. Results: The hospital mortality rate was 3% (22 patients). The following statistically significant threshold values (cut-off points) were obtained in the ROC analysis: aortic cross-clamp time > 93 min AUC (CI) 0.676 (0.640–0.710), p = 0.010; cardiopulmonary bypass time > 144 min AUC (CI) 0.809 (0.778–0.837), p < 0.0001, hemoglobin before op <120 g/L. AUC (CI) 0.762 (0.728–0.793), p < 0.0001, hematocrit before op <39% AUC (CI) 0.755 (0.721–0.786), p < 0.001, end-diastolic dimension index >2.39 AUC (CI) 0.647 (0.607–0.686), p = 0.014, end-systolic dimension index > 1.68 AUC (CI) 0.657 (0.617–0.695), p = 0.009. Statistically significant independent predictors of hospital mortality were identified: BMI > 30 kg/m2 (OR 2.84; CI 1.15–7.01), ischemic heart disease (OR 3.65; CI 1.01–13.2), diabetes (OR 3.88; CI 1.38–10.9), frequent ventricular ectopy before operation (OR 9.78; CI 1.91–50.2), mitral valve repair (OR 4.47; CI 1.76–11.3), tricuspid valve repair (OR 3.06; CI 1.09–8.58), 3 and more procedures (OR 4.44; CI 1.67–11.8). Conclusions: The hospital mortality rate was 3%. The main indicators associated with the risk of death were: diabetes, overweight (body mass index more than 30 kg/m2), frequent ventricular ectopy before surgery, hemoglobin level below 120 g/L, hematocrit level below 39%, longer cardiopulmonary bypass time and aortic cross-clamp time, additional mitral and tricuspid valve interventions
Local Use of Hydrogel with Amiodarone in Cardiac Surgery: Experiment and Translation to the Clinic
The objective of this study was to study the use of the hydrogel biopolymer based on sodium alginate (“Colegel”) with a drug substance—amiodarone—for the prevention of postoperative atrial fibrillation (POAF) in cardiac surgery. The experimental part of the study was performed on 46 rabbits. Five groups were formed: in the first group, the dose of amiodarone in hydrogel was 1 mg; in the second group—3 mg; in the third group—6 mg; in the fourth group, hydrogel was used without amiodarone; in the fifth group, 60 mg amiodarone was administered intravenously. The animals from each group were removed from the experiment for the pathomorphological study of the heart after 3, 7 and 14 days. The studied endpoints were: the heart rate control; the development of the blockades of the conduction system of the heart; and the development of inflammation according to laboratory pathomorphological studies. The translational clinical part involved a randomized clinical trial which included 60 patients, with an average age of 62 ± 8.5 years. All patients were randomized into two groups: the study group (n = 30, with the application of amiodarone hydrogel) and the control group (n = 30, without the application of amiodarone hydrogel). The dose of amiodarone in the hydrogel material was 60 mg for all patients. The heart rhythm was monitored during 5 days. The primary endpoint was the development of POAF. Secondary endpoints were: the dynamics of heart rate; the duration of the QT and PQ intervals; the development of blockades of the cardiac conduction system; as well as the dynamics of AST and ALT. According to the results of the experimental part, it was found that the method of the local epicardial delivery of amiodarone by the hydrogel material was safe. Hydrogel with amiodarone is effective for reducing the heart rate in the animal experiment in comparison to the control group and the group with the intravenous administration of the drug. The optimal dose of amiodarone in hydrogel was 1 mg per 1 kg. According to the results of the clinical part, it was found that the method of the local epicardial delivery of amiodarone as a hydrogel material proved its safety. Hydrogel with amiodarone at a dose of 60 mg was effective in preventing POAF in patients after coronary artery bypass grafting (CABG) operations in comparison to the control group (p < 0.001). The age and procedure of application of the amiodarone gel were significantly associated with POAF (p = 0.009 and p = 0.011, respectively). The use of hydrogel with amiodarone reduced the probability of developing POAF 18.9-fold. The method of the local epicardial delivery of amiodarone in the form of a hydrogel material is safe. The use of hydrogel with amiodarone after CABG reduced the probability of developing POAF
Long-Term Preoperative Atorvastatin or Rosuvastatin Use in Adult Patients before CABG Does Not Increase Incidence of Postoperative Acute Kidney Injury: A Propensity Score-Matched Analysis
Background: Acute kidney injury (AKI) is among the expected complications of cardiac surgery. Statins with pleiotropic anti-inflammatory and antioxidant effects may be effective in the prevention of AKI. However, the results of studies on the efficacy and safety of statins are varied and require further study. Methods: We conducted a retrospective cohort study to evaluate long-term preoperative intake of atorvastatin and rosuvastatin on the incidence of AKI, based on the “Kidney Disease: Improving Global Outcomes” (KDIGO) criteria in the early postoperative period after coronary artery bypass graft surgery (CABG). We performed propensity score matching to compare the findings in our study groups. The incidence of AKI was assessed on day 2 and day 4 after the surgery. Results: The analysis included 958 patients after CABG. After 1:1 individual matching, based on propensity score, the incidence of AKI was comparable both on day 2 after the surgery (7.4%) between the atorvastatin group and rosuvastatin group (6.5%) (OR: 1.182; 95%Cl 0.411–3.397; p = 0.794), and on postoperative day 4 between the atorvastatin group (3.7%) and the rosuvastatin group (4.6%) (OR: 0.723, 95%Cl 0.187–2.792; p = 0.739). Additionally, there were no statistically significant differences in terms of incidence of AKI after 1:1 individual matching, based on propensity score, between the rosuvastatin group and the control group both on postoperative day 2 (OR: 0.692; 95%Cl 0.252–1.899; p = 0.611) and day 4 (OR: 1.245; 95%Cl 0.525–2.953; p = 0.619); as well as between the atorvastatin group and the control group both on postoperative day 2 (OR: 0.549; 95%Cl 0.208–1.453; p = 0.240) and day 4 (OR: 0.580; 95%Cl 0.135–2.501; p = 0.497). Conclusion: Long-term statin use before CABG did not increase the incidence of postoperative AKI. Further, we revealed no difference in the incidence of post-CABG AKI between the atorvastatin and rosuvastatin groups
Colchicine for Prevention of Atrial Fibrillation after Cardiac Surgery in the Early Postoperative Period
Background. Postoperative atrial fibrillation (POAF) is a common complication of cardiac surgery. It has been proven to be associated with an increase in the incidence of early complications and mortality, an increase in the rate of hospital stay duration, and economic costs of their treatment. One of the pharmaceutical drugs recommended by the American College of Cardiology (ACC)/American Heart Association (AHA) for preventing POAF is colchicine (class IIB). However, the results of research on the efficacy and safety of colchicine are ambiguous and, consequently, require further study. Objective. Evaluating the efficacy of short-term colchicine administration in the prevention of POAF in patients after open-heart surgery. Materials and methods. Double-blind, randomized, placebo-controlled clinical trial. The subjects were randomly assigned to two groups: treatment group (n = 50) with subjects receiving 1 mg of colchicine 24 h before the surgery, as well as on days 2, 3, 4, and 5 in the postoperative period; and the control group (n = 51), receiving placebo on the same schedule. The primary endpoint was the frequency of POAF in both groups within 7 days after surgery. Results. The study included 101 patients (82 men, 19 women). Baseline clinical, laboratory, instrumental, and intraoperative data did not differ statistically significantly between the groups. POAF was detected in 9 patients (18%) of the treatment group and 15 subjects (29.4%) of the control group, which had no statistical significance (odds ratio, OR 0.527; 95% Cl 0.206–1.349; p = 0.178). No statistically significant differences were revealed for most secondary endpoints, as well as between the groups for all laboratory parameters. There were statistically significant differences between the groups solely in the frequency of diarrhea: 16 (32%) patients in the treatment group and 6 (11.8%) subjects in the control group (OR 3.529; 95% Cl 1.249–9.972; p = 0.010). Conclusions. We did not detect any statistical differences between the groups in terms of primary endpoints, which could be due to the insufficient volume of the sample of the study. However, we detected some trends of statistical differences among the groups in terms of some parameters. Clinical Trials Registration. ClinicalTrials. Unique identifier: NCT04224545
The Role of «Novel» Biomarkers of Systemic Inflammation in the Development of Early Hospital Events after Aortic Valve Replacement in Patients with Aortic Stenosis
Introduction. The pathogenesis of aortic stenosis includes the processes of chronic inflammation, calcification, lipid metabolism disorders, and congenital structural changes. The goal of our study was to determine the predictive value of novel biomarkers of systemic inflammation and some hematological indices based on the numbers of leukocytes and their subtypes in the development of early hospital medical conditions after mechanical aortic valve replacement in patients with aortic stenosis. Materials and methods. This was a cohort study involving 363 patients who underwent surgical intervention for aortic valve pathology between 2014 and 2020. The following markers of systemic inflammation and hematological indices were studied: SIRI (Systemic Inflammation Response Index), SII (Systemic Inflammation Index), AISI (Aggregate Index of Systemic Inflammation), NLR (Neutrophil/Lymphocyte Ratio), PLR (Platelet/Lymphocyte Ratio), and MLR (Monocyte/Lymphocyte Ratio). Associations of the levels of these biomarkers and indices with the development of in-hospital death, acute kidney injury, postoperative atrial fibrillation, stroke/acute cerebrovascular accident, and bleeding were calculated. Results. According to an ROC analysis, an SIRI > 1.5 (p 718 (p = 0.002), an AISI > 593 (p 2.48 (p 132 (p = 0.004), and an MLR > 0.332 (p 1.5 (p 2.8 (p 0.392 (p < 0.001) were associated with bleeding in the postoperative period. In a univariate logistic regression, SIRI, SII, AISI, and NLR were statistically significant independent factors associated with in-hospital death. In a multivariate logistic regression model, SIRI was the most powerful marker of systemic inflammation. Conclusion. SIRI, SII, AISI, and NLR as novel biomarkers of systemic inflammation were associated with in-hospital mortality. Of all markers and indices of systemic inflammation in our study, SIRI was the strongest predictor of a poor outcome in the multivariate regression model