Single-layer load-bearing tunnel lining structure in hard rock masses

The paper presents some of the observations made during tunnel construction with a single-layer load-bearing lining in hard rocks. The load-bearing elements of one such lining were observed, as were measures to improve the quality of the material, as well as other required actions to guarantee its stability throughout its lifespan. An extremely important measure is to limit the water inflow into the tunnel, by pressure grouting contemporary grout mixtures into the fractures, commonly referred to as pre-grouting. This paper also shows the construction time and cost of single-layer lining compared to the traditional two-layer lining. The construction expenses of single-layer tunnel lining are slightly lower compared to two-layer tunnel lining. Nevertheless, the main benefit is construction time-savings. The observations are presented using a practical example: a tunnel in the limestone rock near the Mratinja dam, between Plužine and Šćepan polje in Montenegro

Global Analysis of Steel Constructions with Semi-Rigid Connections

In this paper, original extension of classic deformation method for global elastic analysis of steel construction with semi-rigid connections is developed. The original calculation for steel frame structures with semi-rigid connections as a function of rotational rigidity of connection, a realistic parameter for determination of both tension and deformation fields of connection as well as entire construction, has been derived in detail. Due to its generality, simplicity and straight-forward calculation, the method developed in this paper is convenient for both computational utilization and hand calculations. For introduced rotational rigidity of realistic connections, the expressions for determination of bending moments at ends of semi-rigidly connected elements have been derived as well as conditional equations for determination of deformation-unspecified values at static load by first-order theory. The obtained results are illustrated in detail on a numerical example. Their comparison with the results of FEM analysis was provided

COMPARATIVE ANALYSIS OF USING DEGREE OF RIGIDITY AND ROTATIONAL STIFFNESS OF CONNECTIONS IN STRUCTURAL DESIGN

Using classical formulation of stiffness method, impact of semi-rigid connections on the stresses and strains can be analyzed by the degree of rigidity or by rotational stiffness of connections. In this paper, functional dependence between the degree of rigidity and rotational stiffness of connections is formulated and the comparative analysis of these two approaches in the analysis of semi-rigid connections behavior of members in real structures, is implemented

"Siliceous bacteria" of ash deposits of the thermal power plants as indicators of their potential application for bioremediation

Poster presented at: IX Kongres mikrobiologa Srbije-MIKROMED 2013,30. maj-01. jun 2013, BeogradAbstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5052

Oxidation-reduction potential in the milk from mothers of preterm infants

Health benefits of mother's milk depend on the level of the total antioxidant capacity (TAC). In mother's milk, the TAC should refer to the sum of activities derived from active enzymatic antioxidant systems (e.g. superoxide dismutase, catalase, glutathione peroxidase etc.), non-enzymatic antioxidants, such as vitamins C and E, and the presence of other bioactive factors (e.g. lactoferrin, uric acid etc.). Measuring oxidation-reduction potential (ORP) using RedoxSYS Analyzer may be an alternative to classic methods of measuring TAC. We compared the results of ORR and ascorbic acid content in milk from mothers of preterm infants.Abstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5531]Poster presented at 3rd International Conference on Nutrition & Growth, March 17-19, 2016, Vienna, Austri

Oxidation-reduction potential in the milk from mothers of preterm infants

Health benefits of mother's milk depend on the level of the total antioxidant capacity (TAC). In mother's milk, the TAC should refer to the sum of activities derived from active enzymatic antioxidant systems (e.g. superoxide dismutase, catalase, glutathione peroxidase etc.), non-enzymatic antioxidants, such as vitamins C and E, and the presence of other bioactive factors (e.g. lactoferrin, uric acid etc.). Measuring oxidation-reduction potential (ORP) using RedoxSYS Analyzer may be an alternative to classic methods of measuring TAC. We compared the results of ORR and ascorbic acid content in milk from mothers of preterm infants.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5532

Hydroxil Radical Scavenging Activity of Preterm Mothers Milks in the Fenton System

Mothers milk have antioxidative effects against Fenton system via HO radical scavenging. Mother's milk from woman's after preterm delivery antioxidative properties are not examined in details. We examined hydroxil radical scavenging activity of preterm mothers milks in the Fenton system.Poster presented at 2nd National Food Conference, March 20th -21st, 2015, Sofia, BulgariaAbstract: [https://cer.ihtm.bg.ac.rs/handle/123456789/5543

Hydroxil Radical Scavenging Activity of Preterm Mothers Milks in the Fenton System

Mothers milk have antioxidative effects against Fenton system via HO radical scavenging. Mother's milk from woman's after preterm delivery antioxidative properties are not examined in details. We examined hydroxil radical scavenging activity of preterm mothers milks in the Fenton system.Poster: [https://cer.ihtm.bg.ac.rs/handle/123456789/5544

Lack of association between low HDL-cholesterol and elevated circulating cellular adhesion molecules in normolipidemic CAD patients and healthy subjects

High plasma HDL-cholesterol (HDL-c) is a well-established protective factor in coronary artery disease (CAD). One of its potential protective mechanisms is the inhibition of the cytokine-induced upregulation of expression of cellular adhesion molecules (CAMs). High sCAM levels were found to be associated with low HDL-c in some studies performed mostly in hyperlipidemic subjects, but this association has not yet been investigated in CAD patients. In addition, conflicting results were obtained from in vitro studies that explored the proposed HDL effect on cytokine-induced CAM expression. The aim of the present case-control study was to investigate whether low HDL-c values are associated with CAM overexpression in normolipidemic CAD patients and healthy individuals, matched according to age and gender. Plasma HDL-c, sICAM-1, sVCAM-1, and sE-selectin were measured in 37 normolipidemic patients with angiographically verified coronary artery disease and in 52 healthy normolipidemic subjects. The sCAM values obtained in the subjects (patients or controls) with low HDL-c levels ( lt 1.03 mmol/L) were compared with the values in the subjects with high HDL-c (>= 1.03 mmol/L). No significant difference was found between sICAM-1, sVCAM-1, and E-selectin values obtained in subjects with low and high HDL-c, either among the patients or the healthy controls. In conclusion, low HDL-c levels are not associated with CAM overexpression in normolipidemic CAD patients and healthy subjects

Telomere-telomerase system status in patients with acute myocardial infarction with ST-segment elevation – relationship with oxidative stress

Introduction: Telomeres are protective chromosomal ends. Short telomeres are a proven biomarker of biological aging. We aimed to find an association of telomere length and telomerase activity in circulating leukocytes and thromboaspirates of patients with acute myocardial infarction. Furthermore, association of the telomere-telomerase system with oxidative stress markers (as common risk factors for coronary artery disease (CAD)) was tested. Material and methods: Patients were selected from the patients admitted to the intensive care unit with acute myocardial infarction with ST-segment elevation (STEMI), with the following inclusion criteria – STEMI patients between 18 and 80 years old of both genders and candidates for primary percutaneous coronary intervention, with infarction pain present for a maximum of 12 h. In all the patients leukocyte telomere length, telomerase activity and scores related to oxidative-stress status (Protective, Damage and OXY) were evaluated. Results: Patients were divided into different groups: with stable angina pectoris (AP) (n = 22), acute myocardial infarction with: STEMI (n = 93), non-obstructive coronary arteries (MINOCA) (n = 7), blood vessel rupture (n = 6) at three time points, and compared to the group of 84 healthy subjects. Telomerase activity was significantly higher in all CAD sub-groups compared to the control group (AP = 0.373 (0.355–0.386), STEMI = 0.375 (0.349–0.395), MINOCA = 0.391 (0.366–0.401), blood vessel rupture = 0.360 (0.352–0.385) vs. CG = 0.069 (0.061–0.081), p < 0.001), while telomeres were significantly shorter in STEMI, MINOCA and blood vessel rupture groups compared to the control group (STEMI = 1.179 (0.931–1.376), MINOCA = 1.026 (0.951–1.070), blood vessel rupture = 1.089 (0.842–1.173) vs. CG = 1.329 (1.096–1.624), p = 0.030]. Values of OXY score were significantly higher in STEMI and MINOCA patients compared to the control group and AP patients (5.83 (4.55–7.54) and 10.28 (9.19–10.72) vs. 4.94 (3.29–6.18) and 4.18 (2.58–4.86), p < 0.001). Longer telomeres and higher telomerase activity were found in thromboaspirates, compared to the peripheral blood leukocytes in the same patients (1.25 (1.01–1.84) vs. 1.18 (0.909–1.516), p = 0.036; and 0.366 (0.367–0.379) vs. 0.366 (0.367–0.379), p < 0.001, respectively). In addition, telomere length and telomerase activity had good diagnostic ability to separate STEMI patients from healthy persons. Conclusions: Leukocyte telomere length and telomerase activity can differentiate CAD patients from healthy persons, and relate CAD to oxidative stress