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Taking into account the history of problems concerning high-strength low-alloyed (HSLA) steel used for manufacturing of penstocks (partly presented by authors in previous studies), this paper is oriented toward specifics on structural integrity assessment of construction in question. Experimental testing of parent material, i.e. HSLA steel, such as microstructure analysis, impact toughness testing and hardness measuring provide insight into characteristics of parent material properties. Considering geometry of penstock and specific requirements, finite element method (FEM), i.e. ABAQUS, was used to assess the structural integrity of penstock as a whole, specific the longitudinal welded joint under the different internal (working) pressure. It should be emphasized that a slight undermatching effect was investigated by FEM approach in this case. Focus is being put on plastic deformation investigation on aforementioned welded joint under maximum internal pressure of 120 bar.

The selection of appropriate suppliers in an uncertain environment influences the sustainability and the competitive advantage of the automotive industry and hence presents one of the significant management problems. In the literature, it is suggested that an acceptable supplier may be determined concerning many criteria. In this manuscript, criteria selection is based on the relevant literature. Handling of different uncertainties is performed by using the type-2 fuzzy sets that have the capability of handling more considered impreciseness and uncertainties. In the presented research, the two-state model is proposed. In the first stage, the relative importance of criteria and sub-criteria are described by pre-defined linguistic expressions which are modeled by the interval type-2 triangular fuzzy numbers (IT2TFNs). The fuzzy weights vectors are given by using the fuzzy Analytic Hierarchical Process with IT2TFNs (IT2FAHP). After that, the ranking of suppliers is based on the modified Multi-Attributive Border Approximation area Comparison method (MABAC) with IT2TFNs (IT2FMABAC). The extension of the conventional MABAC includes: (a) modeling of sub-criteria values of IT2TFNs, (b) the fuzzy criteria values are calculated by using fuzzy algebra rules, (c) belonging of each supplier to border approximation areas (BAAs) is given by using procedure, and (d) the distance of suppliers to BAAs is determined by using the normalized Euclidean distance formulas. The proposed model is tested on the real-life data from the automotive supply chain. Through the presented research, it is shown that the proposed IT2FMABAC is a useful and reliable tool for the rational purchasing decision-making process.

The superstreet intersection (or restricted crossing U-turn-, J-turn intersection) fixed-time traffic control system was developed in this study. The optimal (or near-optimal) values of cycle length, splits, and offsets were discovered by minimizing the experienced travel time of all network users traveling through the superstreet intersection. The optimization procedure used was based on the bee colony optimization (BCO) metaheuristic. The BCO is a stochastic, random-search, population-based technique, inspired by the foraging behavior of honey bees. The BCO belongs to the class of swarm intelligence methods. A set of numerical experiments was performed. Superstreet intersection configurations that allowed direct left turns from the major street, as well as configurations with no direct left turns, were analyzed within numerical experiments. The obtained results showed that BCO outperformed the traditional Webster approach in the superstreet geometrical configurations considered.

In this article, we study the application of NetworkX, a Python library for dealing with traffic networks, to the problem of signal optimization at a single intersection. We use the shortest-path algorithms such as Bellman-Ford (Dynamic Programming), A star (A*), and Dijkstra’s algorithm to compute an optimal solution to the problem. We consider both undersaturated and oversaturated traffic conditions. The results show that we find optimal results with short Central Processor Unit (CPU) time using all the applied algorithms, where Dijkstra’s algorithm slightly outperformed others. Moreover, we show that bee colony optimization can find the optimal solution for all tested problems with different degrees of computational complexity for less CPU time, which is a new contribution to knowledge in this field.

Diabetic cardiomyopathy (DCM) is characterized by cardiac hypertrophy, fibrosis, oxidative stress and inflammation. Trimetazidine (TMZ), a potent metabolism modulator, has been shown to be cardioprotective in experimental models of ischaemia-reperfusion and type 2 diabetes-induced cardiomyopathy. The present study examined whether TMZ inhibits cardiomyopathy induced by insulin-dependent type 1 diabetes. Wistar rats were randomly divided into control group (vehicle alone), diabetes mellitus (DM; induced by streptozocin (STZ) injection) group and DM treated with TMZ (DM/TMZ) group. Cardiac function, histology, plasma biochemistry and molecular mechanism were assessed. STZ induced diabetes in rats as indicated by hyperglycemia, increased and decreased levels of advanced glycation end products (AGEs) and insulin respectively. Diabetic rats were characterized by left ventricular dysfunction, cardiachypertrophy and fibrosis and signs of inflammation and oxidative stress in the myocardium, which were accompanied by elevated levels of NADPH oxidase 2 (Nox2) and transient receptor potential channel 3 (TRPC3) in the heart. TMZ treatment ameliorated diabetes-associated structural and functional alterations by inhibiting Nox2 and TRPC3 without having any effects on glucose, insulin and AGEs levels. These results suggest that TMZ could be used as a therapy to treat cardiomyopathy associated with type 1 induced diabetes mellitus.

Some recent studies associated insulin therapy with negative cardiovascular events and shorter lifespan. SUR2A, a KATPchannel subunit, regulate cardioprotection and cardiac ageing. Here, we have tested whether glucose and insulin regulate expression of SUR2A/KATPchannel subunits and resistance to metabolic stress in heart H9c2 cells. Absence of glucose in culture media decreased SUR2A mRNA, while mRNAs of Kir6.2, Kir6.1, SUR1 and IES SUR2B were increased. 2-deoxyglucose (50 mM) decreased mRNAs of SUR2A, SUR2B and SUR1, did not affect IES SUR2A and IES SUR2B mRNAs and increased Kir6.2 mRNA. No glucose and 2-deoxyglucose (50 mM) decreased resistance to an inhibitor of oxidative phosphorylation, DNP (10 mM). 50 mM glucose did not alter KATPchannel subunits nor cellular resistance to DNP (10 mM). Insulin (20 ng/ml) in both physiological and high glucose (50 mM) down-regulated SUR2A while upregulating Kir6.1 and Kir6.2 (in high glucose only). Insulin (20 ng/ml) in physiological and high glucose decreased cell survival in DNP (10 mM). As opposed to Kir6.2, infection with SUR2A resulted in titre-dependent cytoprotection. We conclude that insulin decreases resistance to metabolic stress in H9c2 cells by decreasing SUR2A expression. Lower cardiac SUR2A levels underlie increased myocardial susceptibility to metabolic stress and shorter lifespan.

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In order to give reasons for further advanced multi-faceted research of geothermal utilization, geothermal energy utilization and its integration in urban planning in the long run in the City of Nis were analysed. Regional aspect of this utilization is considered, which is novelty in the planning of the city. The arguments are supported by expert opinions on geothermal utilization acquired abroad and in Serbia that suggest geothermal use within proposals for an eco-city.

Dust aerosols are abundant in the atmosphere and are very efficient ice nucleating particles at temperatures below −15°C. Depending on temperature, dust particles containing certain minerals (i.e., feldspar and quartz) are the most active as ice nuclei. A mineralogy‐sensitive immersion freezing parameterization for ice nucleating particle concentration (INPC) is implemented in Dust Regional Atmospheric Model (DREAM) for the first time. Additionally, four mineralogy‐indifferent parameterizations are implemented, two for immersion freezing and two for deposition nucleation. Dust concentration and its feldspar and quartz fractions are forecasted by DREAM for a dust episode in the Mediterranean in April 2016. DREAM results are compared with vertical profiles of cloud‐relevant dust concentrations and INPC from ground‐based lidar measurements in Potenza, Italy and Nicosia, Cyprus. INPC predictions are also compared with vertical profiles of ice crystal number concentration (ICNC) from satellite observations for two overpasses over the dust plume. The model successfully simulates the evolution and vertical extent of the dust plume. Mineralogy‐sensitive and mineralogy‐indifferent INPC parameterization results generally differ by about an order of magnitude. Forecasted INPC and observed ICNC values differ by an order of magnitude for all parameterizations. Feldspar fraction increase within a dust plume during transport can increase INPC by around 6% at −35°C, and up to 17% at −25°C, but sedimentation can reduce this effect. Over the Atlantic, mineralogy‐sensitive parameterization predicts horizontal distribution of clouds with higher probability of success, while in the Mediterranean; the results for different parameterizations show lower variability. Supercooled water droplets in clouds can freeze at temperatures around −37°C. Dust particles immersed in water droplets can enhance formation of ice crystals at higher temperatures. The efficiency of dust particles in ice initiation has been attributed to the presence of ice‐active minerals, such as feldspar and quartz. In this work, we use a computer model (DREAM) to calculate how mineral dust particles from Sahara and Middle East are lifted and transported by the atmospheric flow. The model, includes equations that predict ice initiation depending on dust concentration and mineral composition, temperature and humidity. Atmospheric remote sensing observations from lidar and radar ground‐based and satellite platforms provide information about vertical structures of dust plumes, their horizontal extent, and estimations of the dust particle and ice crystal concentrations in the atmosphere. We simulate a dust plume development in Mediterranean in April 2016 and compare results with data from lidar stations (in Potenza, Italy and Nicosia, Cyprus) and from satellites. DREAM successfully predicts horizontal and vertical extent of the dust plume and provides good estimations of ice initiation. Feldspar, the most efficient mineral in ice initiation, is mostly present in larger particles and can be more easily deposited during atmospheric transport. Mineralogy‐sensitive setup predicts spatial distribution of ice nucleating particle concentrations (INPC) in a dust plume in MediterraneanMineralogy‐sensitive prediction of INPC is within the range of mineralogy‐indifferent ones and in agreement with measurements below −20°CFeldspar content in a dust plume affects ice initiation by around 6% at −35°C, and up to 17% at −25°C, but sedimentation reduces this effect Mineralogy‐sensitive setup predicts spatial distribution of ice nucleating particle concentrations (INPC) in a dust plume in Mediterranean Mineralogy‐sensitive prediction of INPC is within the range of mineralogy‐indifferent ones and in agreement with measurements below −20°C Feldspar content in a dust plume affects ice initiation by around 6% at −35°C, and up to 17% at −25°C, but sedimentation reduces this effect

Sarcolemmal ATP‐sensitive K+(KATP) channels are abundant in cardiac myocytes where they couple the cellular metabolic state with membrane excitability. Structurally, these channels are composed of Kir6.2, a pore‐forming subunit, SUR2A, a regulatory subunit, and at least four accessory proteins. The activation of KATPchannels occurs during ischaemia to promote cardiac viability under this adverse condition. Age‐dependent changes in the myocardial susceptibility to ischaemia have been reported in experimental animals as well as in humans. Recent research has demonstrated that ageing is associated with a decrease in the number of cardiac sarcolemmal KATPchannels in hearts from females, but not males. This alteration is likely to be due to an age‐dependent decrease in the concentration of circulating estrogens. In the heart, SUR2A is the least expressed protein of all KATPchannel‐forming proteins. The consequence of this phenomenon is that the level of SUR2A is the main factor controlling the number of sarcolemmal KATPchannels. Estrogens specifically up‐regulate SUR2A and govern the number of sarcolemmal KATPchannels, and this may explain the effect of decreasing estrogen levels on the heart. An age‐dependent decrease in the number of sarcolemmal KATPchannels generates a cardiac phenotype more sensitive to ischaemia, which seems to be responsible for the ageing‐associated decrease in myocardial tolerance to stress that occurs in elderly women.

Sarcolemmal ATP-sensitive K+(KATP) channels are abundant in cardiac myocytes where they couple the cellular metabolic state with membrane excitability. Structurally, these channels are composed of Kir6.2, a pore-forming subunit, SUR2A, a regulatory subunit, and at least four accessory proteins. The activation of KATPchannels occurs during ischaemia to promote cardiac viability under this adverse condition. Age-dependent changes in the myocardial susceptibility to ischaemia have been reported in experimental animals as well as in humans. Recent research has demonstrated that ageing is associated with a decrease in the number of cardiac sarcolemmal KATPchannels in hearts from females, but not males. This alteration is likely to be due to an age-dependent decrease in the concentration of circulating estrogens. In the heart, SUR2A is the least expressed protein of all KATPchannel-forming proteins. The consequence of this phenomenon is that the level of SUR2A is the main factor controlling the number of sarcolemmal KATPchannels. Estrogens specifically up-regulate SUR2A and govern the number of sarcolemmal KATPchannels, and this may explain the effect of decreasing estrogen levels on the heart. An age-dependent decrease in the number of sarcolemmal KATPchannels generates a cardiac phenotype more sensitive to ischaemia, which seems to be responsible for the ageing-associated decrease in myocardial tolerance to stress that occurs in elderly women.

Effects of V1(OPC-21268) and V2(OPC-31260) vasopressin antagonists on blood pressure (BP) short-term variability were investigated in adult spontaneously hypertensive rats (SHR) under basal conditions and after the stimulation of vasopressin release by hemorrhage. BP was recorded intra-arterially and sampled at 20 Hz to be analyzed on a personal computer. BP time spectra were calculated on 30 stationary overlapping 2048 point-time series. Spectral power was estimated in total (0.00976 – 3 Hz), very low frequency (VLF: 0.00976 – 0.195 Hz), low frequency (LF: 0.195 – 0.605 Hz), and high frequency (HF: 0.8 – 3 Hz) regions. Under basal conditions a V1antagonist (5 mg/kg, i.v.) decreased BP without affecting BP variability, while combined (V1+V2) blockade or V2blockade (1 mg/kg, i.v.) alone did not affect cardiovascular parameters. Mild hemorrhage (5 ml/kg per min) increased HF-BP variability, while moderate (10 ml/kg per min) and massive (15 ml/kg per min) hemorrhage did not affect it. In V1, but not V2, antagonist pre-treated SHR HF-BP increased significantly after moderate and massive hemorrhage. V1or V2antagonist pre-treatment also enhanced VLF-BP variability during massive hemorrhage. Moreover V1blockade prevented hemorrhage-induced bradycardia, while V2blockade potentiated it. It follows that in adult SHR, vasopressin buffers BP oscillations in HF and VLF frequency domains only in hypovolaemic conditions and that the modulation of the autonomic adjustment of the HR to hemorrhage by vasopressin is preserved.

OBJECTIVES

OBJECTIVES

While pregnancy is associated with adjustments in cardiovascular function, the morphology of the vascular system during pregnancy has been generally viewed as being very stable. However, recently we have demonstrated that pregnancy remodels the aorta and the carotid artery. In the present study, we assessed the morphological characteristics of the guinea-pig femoral artery during different stages of pregnancy using light and electron microscopy. There were no significant differences between external and internal diameters, wall thickness, total cross-sectional area and cross-sectional areas of lumen, intima, media, and adventitia of femoral arteries from non-pregnant and early-, mid- and late-pregnant guinea-pigs (n = 8–10). In previous studies, we have shown that the morphology of vascular smooth muscle and endothelial cells in the aorta and the carotid artery may be altered by pregnancy. Therefore, to test this possibility we measured diameters as well as cross-sectional areas of femoral arterial muscle and endothelial cells using electron microscopy. These parameters, at the electron microscopy level, were also not significantly changed by pregnancy (n = 8–10). It is concluded that the morphology of the guinea-pig femoral artery is not altered during pregnancy. In this regard, this study demonstrated that pregnancy-induced vascular remodelling varies between blood vessels that undergo the same functional alterations. Therefore, this may suggest that pregnancy-induced changes in blood flow through different vascular beds are not the most important factor involved in vascular remodelling observed during pregnancy. Rather, it is possible that haemodynamic-independent factors regulate pregnancy-mediated structural changes of the vascular wall.

The effect of oxytocin on endothelium‐intact and endothelium‐denuded segments of the human uterine artery rings was investigated.In both types of preparation oxytocin induced contraction of human uterine artery with similar potency and efficacy (pEC50values: 6.95±0.05 vs 7.06±0.01; maximal response values: 61±4.1% vs 63±5.1% for arteries with and without endothelium, respectively).In contrast, human uterine arteries, both intact and denuded of endothelium, did not respond to the addition of the selective oxytocin receptor agonist, [Thr4, Gly7]oxytocin (10 nM–1 μM).The vasopressin receptor antagonists, [d(CH2)5Tyr(Me)]AVP (10–100 nM) and [d(CH2)5,D‐Ile2,Ile4]AVP (300 nM–3 μM) produced parallel rightward shifts of the curves for oxytocin. The Schild plots constrained to a slope of unity gave the following −log KBvalues: [d(CH2)5Tyr(Me)] AVP vs [d(CH2)5,D‐Ile2,Ile4] AVP 9.24 vs 6.91 and 9.26 vs 6.84 for human uterine artery with intact and those denuded of endothelium, respectively. In contrast, in both types of preparations the oxytocin receptor antagonist, [d(CH2)5Tyr(OMe), 2Orn8]vasotocin (1 μM), did not significantly affect oxytocin‐induced contractions.The calculated pKAvalues for oxytocin itself also did not differ between preparations: 6.56 and 6.43 for human uterine artery with and without endothelium, respectively. In both types of preparations, the receptor reserve (KA/EC50) was close to unity (intact vs denuded: 3.9 vs 3.0).It is concluded that, in human uterine artery, oxytocin induces contractions that are not modulated by the endothelium. It is likely that oxytocin acts as a partial agonist on human uterine artery, regardless of the endothelial condition. On the basis of differential antagonists affinity and affinity of oxytocin itself, it is probable that receptors involved in oxytocin‐induced contraction in human uterine arteries belong to the V1Avasopressin receptors.