Hemijska analiza lako isparljivih komponenti, biološka aktivnost i hemotaksonomske karakteristike vrsta roda Chaerophyllum L. (Apiaceae) sa područja Srbije

This doctoral dissertation reports the chemical composition of the headspace volatiles (HS) and essential oils obtained from different species of genus Chaerophyllum L. (Apiaceae) from the territory of Serbia and Montenegro determined by GC and GC/MS analyses. The obtained results show that the chemical composition of the oil depends on the part of the plant which is analyzed and that the main differences were noticed between aerial parts and the root samples. Substrate - habitat and climatic conditions of the development of the tested plant species do not significantly affect the composition of essential oils. The antioxidant activity of essential oils was investigated using five different methods and obtained results indicate that all oil samples have a weak antioxidant potential. The results of antibacterial assay showed that investigated samples exhibit some antibacterial activity against tested Gram-positive bacteria while they were inactive against Gram-negative bacteria. Chemotaxonomic classification of species of the genera Chaerophyllum L. and Myrrhoides Fabr. was performed using the classes of compounds and main components of essential oils as chemotaxonomic markers for statistical processing. The results obtained show that the use of essential oils as chemotaxonomic markers makes sense and that morphological characters alone are not sufficient for complete identification of plant species

CONTROL OF MHD MICROPOLAR FLUID FLOW

In this paper, the steady flow and heat transfer of an incompressible electrically conducting micropolar fluid through a parallel plate channel is investigated. The upper and lower plate have been kept at the two constant different temperatures and the plates are electrically insulated. The applied magnetic field is perpendicular to the flow, while the Reynolds number is significantly lower than one i.e. the considered problem is in induction-less approximation. The general equations that describe the discussed problem under the adopted assumptions are reduced to ordinary differential equations and closed-form solutions are obtained. The influences of each of the governing parameters on velocity, heat transfer on the plates (Nusselt number), flow rate and skin friction are discussed with the aid of graphs

Biocompatibility and cytotoxicity study of nanophotonic rigid gas permeable contact lens material

Since materials on nanoscale have different characteristics from materials on macro scale their biocompatibility should be precisely and specifically investigated. Fullerenes, the third carbon allotrope, are one of the most used nanomaterials. The least stable and the most common is fullerene C-60. One of the main disadvantages of fullerene is its low solubility in water. In order to make it soluble, it must be functionalized with polar groups such as -OH and -COOH. From all the water soluble fullerenes the most important ones are those with -OH groups attached named fullerols. We have developed new materials for contact lenses by adding fullerene (C-60) and fullerol (C-60(OH)(24)) into PMMA. The aim of our investigation was to compare the influences of those materials on aqueous solutions similar to tear film. For the analysis of the solutions we used opto-magnetic imaging and IR spectroscopy. The acquired spectrums were commented and compared with the standard contact lens material, which was analyzed by the same methods. The ISO 10993 cytotoxicity test on extract of nanophotonic material with incorporated C-60 was done as well. This research contributes to better understanding of the biocompatibility of new rigid gas permeable contact lens materials

Different models of automata with fuzzy states

In this paper we provide a general definition of automata with fuzzy stateswhich includes as its special cases automata used by Lin et al. [29], Liu and Qiu [30,31,42]and Xing et al. [56] in the study of fuzzy discrete event systems, as well as various typesof automata constructed in [14,15,18,32] for the purpose of the determinization of fuzzyautomata. We explain the relationships between these differentmodels of automata withfuzzy states and showthat every crisp-deterministic fuzzy automaton can be transformedinto a language-equivalent automaton with fuzzy states, and vice versa

Determination of phenol content and antioxidant activity of leek (Allium Porrum L.) extract

From molecules to Functionalised Materials : Intensive Lecture Course : March 16-20, Skopje, Republic of Macedonia, 2011

Should MTHFR 1298 A>C be tested together with MTHFR 677 C>T polymorphism in women with reproductive challenges?

Methylenetetrahydrofolate reductase (MTHFR) plays a critical role in the folate metabolism. The polymorphism 677C > T of the MTHFR gene, producing thermolabile enzyme with decreased function, is widely studied and associated with many conditions. Additionally, it has been shown that another polymorphism, 1298A > C, also reduces the activity of this enzyme, although to a lesser extent. The aim of this study is to evaluate the clinical informativeness of testing both MTHFR polymorphisms. Genomic DNA, were extracted from peripheral blood of 180 female patients with pregnancy complications and 183 healthy female controls, and genotyped for MTHFR 677C > T and 1298A > C loci, using TaqMan assays. Our study found similar frequency of alleles and genotypes between two groups. Based on MTHFR 677C > T genotype, 11.7% of patients homozygous for this mutation were under the possible risk. When the position 1298 was included in the testing, 22.8% of the patients were heterozygous for both polymorphisms. Additionally, 8.9% of the patients were homozygous only for the MTHFR 1298 mutation. Although, there was no differences compared to healthy control (p > 0.05), 43% of patients were found to have elevated risk which is about four time higher than results with only MTHFR 677C > T genotyping. After obtaining information for the 677 position, testing for the second polymorphism (1298A > C) should be considered, since we have shown that it dramatically increases the rate of detection of patients who are potentially at risk for MTHFR associated conditions

Electro-Magnetoconvection of Conductive Immiscible Pure Fluid and Nanofluid

This paper discusses the magnetohydrodynamic flow and heat transfer in a horizontal channel whose top and bottom halves have different or the same permeability. The top half of the channel is saturated with oil and the bottom half with a water-based nanofluid. The channel is under the influence of an external homogeneous vertical magnetic field and an external homogeneous electric field perpendicular to the vertical longitudinal plane of the channel. The Darcy model is used to determine the fluid flow and heat transfer. Expressions for velocity and temperature distributions are defined and presented graphically for different values of the dimensionless parameters. The Nusselt numbers are determined and given in a table. The paper also investigates the influence of the Hartmann number, the porosity factor, the electrical load factor and the volume fraction of the nanofluid on velocity and temperature distributions in the channel as well as the Nusselt numbers. It has been shown that an increase in the volume fraction of nanoparticles leads to a decrease in the temperature in the channel. Increasing the porosity factor reduces the fluid velocity in the channel and increases the temperature. The Hartmann number increases the temperature in the channel. Higher absolute values of the load factor correspond to higher temperatures. By changing the value of this factor, the direction of fluid flow can also be changed

Ispitivanje uticaja nanofotoničnih tvrdih gaspropusnih kontaktnih sočiva na fiziološki rastvor akvafotomikom i opto-magnetnom imidžing spektroskopijom

Contact lenses represent biomaterials whose main purpose is to correct the specific refractive anomaly of the eye. Since the visible light on its way to the perceptive part of the eye has to pass through the contact lens, the characteristics of the materials can significantly modify it. Biocompatibility of the lens surface is one of the most important issues in achieving contact lens wear without problems. We have developed new nanophotonic contact lens materials by adding nanoparticles of fullerene and their derivatives into standard PMMA RGP material. The aim of our investigation was to compare the influences of these materials on saline which is similar to tear film. We used NIR spectroscopy based on 12 vibration modes, called Aquaphotomics and Opto-magnetic imaging (OMI) spectroscopy as methods for characterizing the samples. The acquired spectrums were commented and compared with the standard contact lens material, which was analyzed by the same method.Kontaktna sočiva predstavljaju biomaterijale čija je glavna svrha ispravljanje specifičnih refraktivnih anomalija oka. S obzirom da vidljiva svetlost na svom putu do perceptivnog dela oka mora da prođe kroz kontaktno sočivo, karakteristike materijala mogu značajno da je izmene. Biokompatibilnost površine sočiva je jedno od najvažnijih pitanja u postizanju nošenja kontaktnih sočiva bez problema. Razvijeni su novi nanofotonični materijali za kontaktna sočiva dodavanjem nanočestica fulerena i njihovih derivata u standardni PMMA materijal za tvrda gas propusna kontaktna sočiva. Cilj našeg istraživanja je bilo poređenje uticaja ovih materijala na fiziološki rastvor koji je sličan suznom filmu. Za karakterizaciju uzoraka koristili smo blisku infracrvenu spektroskopiju zasnovanu na 12 vibracionih modova, poznatiju kao Akvafotomika. Dobijeni spektri su komentarisani i upoređeni sa standardnim materijalom za kontaktna sočiva, koji je analiziran istom metodom

CONTROL OF FLOW AND HEAT TRANSFER USING SUCTION, MAGNETIC AND ELECTRIC FIELD

Flow of a viscous incompressible electrically conducting fluid between two infinite horizontal parallel porous plates under a constant pressure gradient or constant flow rate has been considered in the paper. Effects of magnetic field, suction/injection and load factor have been studied in order to control the flow rate, shear stress and heat transfer on the plates. Applied magnetic field is perpendicular to the plates, the channel plates are electrically insulated and through the plates perpendicular to the surface the fluid of the same physical characteristics as the fluid in the basic flow is injected or ejected. An exact solution of governing equation has been obtained in a closed form. The influences of each of the governing parameters on flow rate, shear stress and heat transfer are discussed with the aid of graphs