Short communication: Effect of commercial or depurinized milk diet on plasma advanced oxidation protein products,cardiovascular markers,and bone marrow CD34 stem cell potential in rat experimental hyperuricemia

Cardiovascular repair and myocardial contractility may be improved by migration of bone marrow stem cells (BMSC) and their delivery to the site of injury, a process known as BMSC homing. The aim of our study was to examine the dietary effect of a newly patented depurinized milk (DP) that is almost free of uric acid and purine and pyrimidine compounds compared with a standard commercial 1.5% fat UHT milk diet or allopurinol therapy in rat experimental hyperuricemia. Bone marrow stem cell potential (BMCD34⁺, CD34-postive bone marrow cells), plasma oxidative stress parameters [advanced oxidation protein products, AOPP) and thiobarbituric acid reactive substances (TBARS)], myocardial damage markers [creatine phosphokinase (CPK), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH)], plasma cholesterol, and high-density lipoprotein cholesterol were investigated. The DP milk diet significantly increased the number of BMCD34⁺ stem cells compared with commercial UHT milk. Allopurinol given alone also increased the number of BMCD34⁺. Hyperuricemia caused a significant increase in all plasma enzyme markers for myocardial damage (CPK, LDH, and AST). A cardioprotective effect was achieved with allopurinol but almost equally with DP milk and more than with commercial milk. Regarding plasma AOPP, TBARS, and cholesterol levels, the most effective treatment was DP milk. In conclusion, the protective role of a milk diet on cardiovascular function may be enhanced through the new depurinized milk diet, which may improve cardiovascular system function via increased bone marrow stem cell regenerative potential, decreased plasma oxidative stress parameters, and decreased levels of myocardial damage markers and cholesterol. New dairy technology strategies focused on eliminating harmful milk compounds should be completely nontoxic. Novel milk products should be tested for their ability to improve tissue repair and function.     

Vibrations of prismatic shells with hexagonal cross section

Presented is an approximate method for the vibration analysis of nuclear reactor subassembly ducts in form of slender thin-walled polygonal shells with hexagonal cross section. The method is based on the semimembrane shell theory. Inadequacies of this approximate theory are not expected to play a significant role in the determination of fundamental natural frequencies. According to the simplified theory employed, three basic types of motion appear as independent: purely longitudinal vibrations, flexural vibrations and distortional vibrations.     

Modelling of mercury transport and transformation processes in the Idrijca and Soca river system

In the town of Idrija, Slovenia, the world's second largest mercury mine was active for 500 years and about 37,000 tons of mercury has been lost in the environment. Mercury is still drained from soil, riverbed and floodplains and transported with the Idrijca and Soca Rivers to the Gulf of Trieste. A part of inorganic mercury is methylated either in the river system, or later in the coastal area, and, due to its bioaccumulation and biomagnification represents potential danger to human health. A 1-D aquatic model MeRiMod was used to simulate hydrodynamics and sediment transport in the river system from Idrija to the Soca River mouth. Transport of particle bound and dissolved mercury as well as potential net methylation of mercury in the river system was simulated. The simulation of an observed flood wave with 20-year recurrence period was performed in order to validate the model. Methylation was simulated at lower discharges, as higher methylation rates occur in such conditions. The measurement data and the MeRiMod model were also used to establish a historical mercury mass balance of the Idrijca and Soca Rivers catchment. Sediment core data from the Gulf of Trieste and the measured concentrations from floodplains were used to verify and calibrate the model. Simulations of different high discharges were performed as most of the transport of particulate mercury occurs within flood wave conditions. Compared to the measurements, the results of the model showed an agreement within an order of magnitude, for the transport of total mercury mostly within a factor of 4, and for the methylation within a factor of 5. However, proper trends of the phenomena were obtained by simulations. The combination of modelling and measurements has resulted in some interesting conclusions about the phenomenon of the transport and transformations of mercury in the observed river system.     

Spatial calibration of structured illumination fluorescence microscopy using capillary tissue phantoms

Quantitative assessment of microvascular structure is relevant to the investigations of ischemic injury, reparative angiogenesis and tumor revascularization. In light microscopy applications, thick tissue specimens are necessary to characterize microvascular networks; however, thick tissue leads to image distortions due to out-of-focus light. Structured illumination confocal microscopy is an optical sectioning technique that improves contrast and resolution by using a grid pattern to identify the plane-of-focus within the specimen. Because structured illumination can be applied to wide-field (nonscanning) microscopes, the microcirculation can be studied by sequential intravital and confocal microscopy. To assess the application of structured illumination confocal microscopy to microvessel imaging, we studied cell-sized microspheres and fused silica microcapillary tissue phantoms. As expected, structured illumination produced highly accurate images in the lateral (X-Y) plane, but demonstrated a loss of resolution in the Z-Y plane. Because the magnitude of Z-axis distortion was variable in complex tissues, the silica microcapillaries were used as spatial calibration standards. Morphometric parameters, such as shape factor, were used to empirically optimize Z-axis software compression. We conclude that the silica microcapillaries provide a useful tissue phantom for in vitro studies as well as spatial calibration standard for in vivo morphometry of the microcirculation.     

Preliminary management and optimization of a gas reservoir in central Serbia

Management of hydrocarbon reservoirs is a dynamic, continuous and complex process. It is applied from reservoir discovery to its abandonment, with the objective of achieving maximum profitability by using a recovery process with minimum capital investments and operation costs.The goals of modern system-engineer' approach to hydrocarbon reservoir management are: managing efficiency; adequate and on time decision making; increasing reserves, and oil and gas recovery factor; production increment; risk reduction; investment efficiency; minimizing costs and environmental protection.The gas reservoir “M” is the gas reservoir discovered in central part of Serbia. It was not put in production yet, so it is important to apply reservoir management concepts from the beginning of the production process.Based on production characteristics, this reservoir belongs to a group of smaller gas reservoirs that characterizes most often the Serbian exploitation area. Also, this reservoir fullfils most of criteria for using it as an underground gas storage reservoir. Thus, the analysis of possibilities for conversion into the underground gas storage after certain production period was also considered.The management of gas reservoir “M” has been analyzed by two different approaches. The first one refers to the management of the reservoir as a gas producer during the whole reservoir life. The second management approach considers gas production for a certain period of time, followed by underground gas storage (UGS). In this paper, economic and financial evaluation results are given for the presented options of gas reservoir management.A decision analysis has been applied to select an optimized gas reservoir management approach.Adequate management of this gas reservoir would contribute to further development and reform of Serbia's gas energy sector that is characterized by great dependence on natural gas imports, and a lack of underground gas storage.