Rat duodenal motility in vitro: Prokinetic effects of DL-homocysteine thiolactone and modulation of nitric oxide mediated inhibition

Homocysteine is a significant but modifiable risk factor for vascular diseases. As gastrointestinal smooth musculature is similar to blood vessel muscles, we investigated how elevated homocysteine levels affect nitric oxide-mediated neurotransmission in the gut. There is accumulated evidence that a dysfunction of NO neurons in the myenteric plexus may cause various diseases in the gastrointestinal tract such as achalasia, diabetic gastroparesis and infantile hypertrophic pyloric stenosis. In the present study, we aimed to assess the effects of homocysteine on NO-mediated responses in vitro, and to examine the effects of DL-homocysteine thiolactone on the spontaneous motility of rat duodenum and nitrergic neurotransmission. DL-homocysteine thiolactone concentration of 10 μmol/L leads to the immediate increase in tone, amplitude and frequency of spontaneous movements in isolated rat duodenum. L-NAME (30 μmol/L) leads to an increase in basal tone, amplitude and frequency of spontaneous contractions. The relaxations induced by EFS were significantly reduced in duodenal segments incubated in DL-homocysteine thiolactone compared with the control group. EFS-induced relaxations were inhibited by L-NAME in both experimental and control groups. These results suggest that a high level of homocysteine causes an important impairment of non-adrenergic non-cholinergic innervation of the rat duodenum. [Projekat Ministarstva nauke Republike Srbije, br. 175043

Controlling qubit arrays with anisotropic XXZ Heisenberg interaction by acting on a single qubit

We investigate anisotropic XXZ Heisenberg spin-1/2 chains with control fields acting on one of the end spins, with the aim of exploring local quantum control in arrays of interacting qubits. In this work, which uses a recent Lie-algebraic result on the local controllability of spin chains with "always-on” interactions, we determine piecewise-constant control pulses corresponding to optimal fidelities for quantum gates such as spin-flip (NOT), controlled-NOT (CNOT), and square-root-of-SWAP (). We find the minimal times for realizing different gates depending on the anisotropy parameter Δ of the model, showing that the shortest among these gate times are achieved for particular values of Δ larger than unity. To study the influence of possible imperfections in anticipated experimental realizations of qubit arrays, we analyze the robustness of the obtained results for the gate fidelities to random variations in the control-field amplitudes and finite rise time of the pulses. Finally, we discuss the implications of our study for superconducting charge-qubit array

Electrical Characterization and Impedance Response of Lanthanum Doped Barium Titanate Ceramics

The dielectric permittivity and dissipation factor of La-doped and undoped BaTiO3 were investigated as a function of frequency and temperature. The impedance response was used to study the electrical properties of La-doped BaTiO3 over the temperature range from room temperature (RT) to 350 degrees C. La-doped and undoped BaTiO3, obtained by a modified Pechini method, were sintered in air at 1300 degrees C for 2 and 16 hours. The impedance spectra were analyzed in terms of equivalent circuits involving resistors, capacitors and constant phase elements (CPE). The most suitable electrical circuit for the interpretation of experimental results is found to be the equivalent circuit consisting of resistors and CPE elements which replace the capacitor elements. The contribution of grain boundary resistance to the total resistance of a system is remarkable at low temperature. Dielectric permittivity of doped BaTiO3 was in the range of 8000 to 12000 at 1 kHz and the dissipation factor was less than 1%

Kinetics and mechanism of sphalerite leaching by sodium nitrate in sulphuric acid solution

Interest for application of hydrometallurgical processes in a processing of complex sulphide ores and concentrates has increased in recent years. Their application provides better metal recoveries and reduced emission of gaseous and toxic ageneses in the environment. The kinetics and mechanism of sphalerite leaching from complex sulphide concentrate with sulphuric acid and sodium nitrate solution at standard conditions was presented in this paper. The influences of temperature and time on the leaching degree of zinc were investigated and kinetic analysis of the process was accomplished. With temperature increasing from 60 to 90°C, the zinc leaching increased from 25.23% to 71.66% after 2 hours, i.e. from 59.40% to 99.83% after 4 hours. The selected kinetic model indicated that the diffusion through the product layer was the rate-controlling step during the sphalerite leaching. The activation energy was determined to be 55 kJ/mol in the temperature range 60-90°C. XRD, light microscopy and SEM/EDX analyses of the complex concentrate and leach residue confirmed formation of elemental sulphur and diffusion-controlled leaching mechanism

Effects of moulds on the safety and processing quality of Triticum aestivum

Wheat and wheat products are frequently subjected to mould infestations. Many of them are potential producers of various mycotoxins. Some of the consequences, due to the infestations by genus Fusarium and Alternaria, are mostly: yield loss, decrease of biological and technological quality, and unacceptable quality of infected kernels for the production and processing into human food because of the possible presence of mycotoxins. It is unknown whether and how the contaminated grains are distributed during milling into various flour streams and finished products. Wholegrain flours and related products contain all anatomic parts of kernels, including mycotoxins. It is a known fact that mycotoxins are resistant to thermal degradation, so they do not loose their toxicity during processing. Moulds from genus Fusarium spp. and Alternaria spp. synthesize mycotoxins, mostly zearalenon and ochratoxin A. The aim of the investigation was to examine mould contamination of wheat grain, as well as to identify the isolated species, especially those capable of producing toxins, and to determine their impact on technological quality, safety and sanitary condition of wheat. Six varieties of wheat, contaminated with moulds, were investigated. Each sample was separated manually into four fractions: sound kernels, black germ kernels, kernels infected slightly and those infected severely with Fusarium spp

Dynamic Mechanical Properties of Aramid Fabrics Impregnated with Carbon Nanotube/Poly (Vinyl Butyral)/Ethanol Solution

In this study six samples of polyurethane/p-aramid multiaxial fabric forms (Colon fabrics) were coated with 10 wt.% poly (vinyl butyral) (PVB)/ethanol solution with the addition of multiwalled carbon nanotubes (MWCNT). The solution was impregnated on both sides of each of the fabrics. All composite samples consisted of four layers of the impregnated fabrics. The MWCNT/PVB content was 0, 0.1 and 1 wt.%. The three samples of the fabrics with different MWCNT/PVB content were coated with γ-aminopropyltriethoxysilane (AMEO silane)/ethanol solution due to the surface modification. The mechanical properties of the prepared composite samples were studied by dynamic mechanical analysis (DMA). The 60% increase in storage modulus was achieved by addition of MWCNT and impregnation of aramid fabrics with AMEO silane. The pristine multiwalled carbon nanotubes (MWCNT) were introduced in order to enhance additionally the mechanical properties of the materials for ballistic protection

Determination of inorganic compounds in drinking water on the basis of house water heater scale, part 1: Determination of heavy metals and uranium

The analysis of scale originated from drinking water on the house water heater, showed that scale is basically calcium carbonate that crystallizes hexagonally in the form of calcite. Scale taken as a sample from different spots in Belgrade – upper town of Zemun (sample 1) and Pančevo (sample 2) showed different configuration although it came from the same waterworks. That indicates either that the water flowing through waterworks pipes in different parts of the city is not the same or the waterworks net is not the same (age, maintaining, etc). All the elements which are dominant in drinking water (Ca, Mg, K, and Na), and which could be found in water by natural processes, are by their content far below the values regulated by law. The analysis also showed the presence of many metals: Ti, Pb, Zn, Cu Li, Sr, Cd, and Cr in the first sample, which are not found in the scale taken near Pančevo. The results obtained by calculating the mass concentration in drinking water on the basis of scale content, showed that both waters belonged to the category of low mineral waters. Contents of inorganic substances in these waters (117.85 mg/dm3 for sample 1 or 80.83 mg/dm3 for sample 2) are twice lower than the values predicted by the legislation. Gammaspectrometric analysis indicates the presence of radioactive elements – uranium and strontium which can influence human health

Meat quality characteristics of DurocxYorkshire, DurocxYorkshirexwild boar and wild boar

Chemical composition, pH value, fatty acids profile, cholesterol content, color and sensory analysis of pork meat from Duroc x Yorkshire (D x Y), Duroc x Yorkshire x wild boar (D x Y x WB) crossbreeds and wild boars (WB) was investigated. Samples for all tests were taken from m. longissimus dorsi. Chemical composition and pH value were tested by ISO methods. Fatty acid and cholesterol determination was performed by gas chromatography technique with external standard method. Color was determined instrumentally using the thristimulus colourimeter. The overall sensoric quality (appearance, texture and smell) of samples of raw meat was evaluated. In evaluation of results the scoring system was used. In chemical composition (moisture, fat, protein, ash) and pH values statistically significant difference was noted (p<0,05) between each of the examined groups. Also, among all the examined groups statistically significant difference (p<0,05) was found for fatty acids and cholesterol content. Measurment of the color of meat from all three groups showed that the L*, a * b *, Chroma and Hue angle were also statistically significantly different (p<0,01)

SCADA SYSTEMS IN THE CLOUD AND FOG ENVIRONMENTS: MIGRATION SCENARIOS AND SECURITY ISSUES

This paper addresses scenarios and security issues when migrating SCADA systems to cloud and fog environments. Migration strategies to the cloud refer to different cloud infrastructures (public, private or hybrid) as well as selection of cloud service. Benefits of cloud-based SCADA systems mainly refer to improving economic efficiency. We further address migration risks, with regards to quality of service and cyber security. Challenges in security provisioning encompass security solutions, risk management and test environment. Finally, we address emerging evolution of SCADA toward fog computing, including the three-tier system’s architecture and security issues

Supplementary material for the article: Šoštarić, T. D.; Petrović, M. S.; Pastor, F. T.; Lončarević, D. R.; Petrović, J. T.; Milojković, J. V.; Stojanović, M. D. Study of Heavy Metals Biosorption on Native and Alkali-Treated Apricot Shells and Its Application in Wastewater Treatment. Journal of Molecular Liquids 2018, 259, 340–349. https://doi.org/10.1016/j.molliq.2018.03.055

Supplementary material for: [https://doi.org/10.1016/j.molliq.2018.03.055]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2152]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/2970