Non-invasive screening: The probability of events

Congenital anomalies are the cause of 20.0-25.0% of cases of perinatal death, while 3.0% of children are born with malformations of varying size. We examined the predictive values and defined the credibility ratio of the combined test results. Sensitivity of the test is 94.0%, and specificity is 99.0%. The positive likelihood ratio [likelihood ratio test (LR+)] is 94.00; a negative likelihood ratio [likelihood ratio test (LR-)] is 0.06. The pretest probability that pregnant women carry a fetus with chromosomal abnormality is 1:250. Posttest odds after the combined test to discover this abnormality are 0.3760, and probability of the same case is 0.2732 if it happens that the test result is positive. The result of our study confirms the justification of combined test usage in routine clinical practice, since the posttest odds rate in the case of a positive screening increases several times over (almost 90 times); the probability of detecting a chromosomal abnormality was about 70 times

Planar photonic crystal

We present results of guiding light in a single-line-defect planar photonic crystal (PPC) waveguide with 90° and 60° bends. The wave guiding is obtained by total internal reflection perpendicular to the plane of propagation and by the photonic band gap for the 2D photonic crystal in the plane. The results for photonic waveguiding are shown and demonstrated at 1.5 µm wavelength

Analysis of forensic samples of "Ecstasy" tablets seized in Novi Sad during the 2004 year

The paper presents results of the analysis of illicit synthetic drugs in the form of tablets distributed under the name "Ecstasy", seized by the police in the broader area of Novi Sad 2004. A huge number of tablets has been analyzed (n=121), of various colours and with impressed symbols from the total amount of 93 seizures, which totally amounted to 1458 tablets. Regarding the number of seizures ecstasy (3,4-methylendioxy-N-meth-yl-amphetamine - MDMA) is dominant among all, and according to the quantity of seized tablets it is amphetamine (AP), while other amphetamine-type drugs (methamphetamine MA 3,4-methylendioxiamphetamine - MDA, 3,4-methylendioxi-N-ethyl-amphetamine MDEA) have been found in rather small quantities and very rarely. Tablets mostly contain caffeine as an additive. In the analytical procedure, the samples of tablets were subjected to liquid-liquid extraction and afterwards analyzed on the GCD (GC-EI) Hewlett-Packard instrument. The method is fast reliable and reproducible for the analysis of amphetamine, methamphetamine MDA, MDMA, MDEA, as well as various additives in the samples of seized tablets

Kombucha fermentation on raw extracts of different cultivars of Jerusalem artichoke

Kombucha is a symbiosis between yeasts and acetic bacteria. It usually grows on sweetened black tea, but cultivation is possible on many other substrates. Jerusalem artichoke tubers extract is one of them. Tubers are suitable for the dietetic nutrition because of the low monosaccharide content and presence of some polyfructan ingredients which act as prebiotic. Five different cultivars of Jerusalem artichoke were used for the preparation of substrates for kombucha fermentation. The aim of this paper was the investigation of the influence of different Jerusalem artichoke cultivars on metabolic activity of kombucha. Composition of carbohydrates was followed using thin-layer chromatography and pH, reducing sugars content and yield of biomass were measured. Most of the samples with Jerusalem artichoke tubers extract contained fructose, probably small amount of glucose, fructo-oligosaccharides with different degree of polymerization and, inulin. Considering TLC chromatograms, Jerusalem artichoke cultivar did not affect significantly the composition of oligosaccharides in the fermentative liquid, as only minor differences were observed

Single Color Centers Implanted in Diamond Nanostructures

The development of materials processing techniques for optical diamond nanostructures containing a single color center is an important problem in quantum science and technology. In this work, we present the combination of ion implantation and top-down diamond nanofabrication in two scenarios: diamond nanopillars and diamond nanowires. The first device consists of a 'shallow' implant (~20nm) to generate Nitrogen-vacancy (NV) color centers near the top surface of the diamond crystal. Individual NV centers are then isolated mechanically by dry etching a regular array of nanopillars in the diamond surface. Photon anti-bunching measurements indicate that a high yield (>10%) of the devices contain a single NV center. The second device demonstrates 'deep' (~1\mu m) implantation of individual NV centers into pre-fabricated diamond nanowire. The high single photon flux of the nanowire geometry, combined with the low background fluorescence of the ultrapure diamond, allows us to sustain strong photon anti-bunching even at high pump powers.Comment: 20 pages, 7 figure

Batch fermentation of black tea by kombucha: A contribution to scale-up

Local domestic Kombucha was used in fermentation of 1.5 g L-1 of black tea (Indian tea, " Vitamin ", Horgoš, Serbia and Montenegro), sweetened with approximately 70 g L'1 of sucrose. Inoculation was performed either with 10% or 15% (v/v) of fermentation broth from previous process. The fermentation was conducted in geometrically similar vessels with 0.4 L, 0.8 L, 4 L and 8 L of substrate, at 22±1 °C for 28 days. The samples were analyzed after 3, 4 5, 6, 7, 10, 14 and 28 days, so that their pH values, content of total acids sucrose, glucose and fructose contents, as well as contents of ethanol and vitamin C were determined. Based on the experiment design, the response surface for the product pH, as a function of time, beverage volume and inoculum concentration, was defined in the form of a second-order polynomial. From the obtained response surface, a formula for scaling-up of the process was derived

Reversed-phase thin-layer chromatography behavior of aldopentose derivatives

Quantitative structure-retention relationships (QSRR) have been used to study the chromatographic behavior of some aldopentose. The behavior of aldopentose derivatives was investigated by means of the reversed-phase thin-layer chromatography (RP TLC) on the silica gel impregnated with paraffin oil stationary phases. Binary mixtures of methanol-water, acetone-water and dioxane-water were used as mobile phases. Retention factors, RM0, corresponding to zero percent organic modifier in the aqueous mobile phase was determined. Lipophilicity C0 was calculated as the ratio of the intercept and slope values. There was satisfactory correlation between them and log P values calculated using different theoretical procedures. Some of these correlations offer very good predicting models, which are important for a better understanding of the relationships between chemical structure and retention. The study showed that the hydrophobic parameters RM0 and C0 can be used as a measures of lipophilicity of investigated compounds

Određivanje fenmedifama i desmedifama u komercijalnom herbicidu tečnom hromatografijom pod visokim pritiskom

Betanal AM-11 is the herbicide that is using to control one-year old weeds with wide leafs in sugar beet fields. Active ingredients of the herbicide are phenmedipham and desmedipham. Commercial emulsifiable concentrate (EC) contains 80 g/L ( 10% of each active compound. We applied high performance liquid chromatography (HPLC) with diode array detector (DAD) at 254 nm for the determination of phenmedipham and desmedipham in commercial samples of Betanal AM-11. This method involves reversed-phase separation of the components on C-18 bonded silica with methanol-water (51+49, v/v) as the eluent. The procedure was highly selective and reproducible and can be successfully used in determining contents of phenmedipham and desmedipham on micro and macro levels.Betanal AM-11 je herbicid koji se koristi za suzbijanje jednogodišnjih širokolisnih korova na poljima sa šećernom repom. Aktivni sastojci herbicida su fenmedifam i desmedifam. Komercijalni koncentrat za emulziju (ES) sadrži 80 g/l ( 10% svake aktivne komponente. Za određivanje fenmedifama i desmedifama u komercijalnim uzorcima Betanala AM-11 je primenjena tečna hromatografija pod visokim pritiskom, DAD detektor i talasna dužina od 254 nm. Metod je obuhvatio razdvajanje komponenata na obrnutim fazama sa kolonom C-18 i eluentom metanol-voda (51+49, v/v). Postupak je veoma selektivan i reproduktivan i može se koristiti za određivanje makro- i mikro količina fenmedifama i desmedifama

The effect of total and local irradiation by microwaves on Na+ + K+ and Mg++ - dependent ATP-ase activity of the heart and masseter muscle of rats

Ispitana je Na+ + K+ kao i Mg++ zavisna ATP-azna aktivnost vrha srca, levog i desnog m. masetera pacova izlaganih dejstvu mikrotalasnog zračenja. Rezultati ukazuju na značajno povećanje Na+ + K+ zavisnu ATP-aznu aktivnost (P < 0,01) ispitivanih tkiva za grupu pacova kojima je zračeno čitavo telo,·i značajno smanjenje iste enzimske aktivnosti (P < 0,001) tkiva životinja ,kojima je zračeno desno oko. Mg++ zavisna ATP-azna aktivnost srca i m. masetera u grupi životinja čije je celo telo ozračivano nije značajno promenjena, a statistički je značajno smanjena (P < 0,01) u ispitivanim tkivima grupe pacova kojima je zračeno desno oko, testirana u odnosu na enzimsku aktivnost tkiva kontrolnih pacova.Na+ + K+ dependent ATP-ase activity of the apex of the heart and of the right and left masseter muscle of rats irradiated by microwaves was studied. The results indicate a significantly increased Na+ + K+ -dependent ATP-ase activity for the group of rats whose bodies were totally irradiated and a significantly decreased activity in the tissues of animals whose right eye was irradiated. The activity of Mg++ dependent ATP-ase of the heart and masseter muscle in the group of animals which were totally irradiated did not significantly change. There was, however, a significant decrease in enzyme activity in the studied tissues of rats with the irradiated right eye