Cross Metathesis Assisted Solid-Phase Synthesis of Glycopeptoids

A solid-phase synthesis of glycopeptoids was explored through olefin cross metathesis (CM). Peptoids and sugar derivatives with appropriate olefin moieties were coupled in the presence of an olefin metathesis catalyst to afford glycopeptoids in good yields. This systematic solid-phase CM study can provide facile access to the molecular sources of glycopeptidomimetics and postchemical modifications on various molecular scaffolds

Recent advances in numerical simulation and control of asymmetric flows around slender bodies

The problems of asymmetric flow around slender bodies and its control are formulated using the unsteady, compressible, thin-layer or full Navier-Stokes equations which are solved using an implicit, flux-difference splitting, finite-volume scheme. The problem is numerically simulated for both locally-conical and three-dimensional flows. The numerical applications include studies of the effects of relative incidence, Mach number and Reynolds number on the flow asymmetry. For the control of flow asymmetry, the numerical simulation cover passive and active control methods. For the passive control, the effectiveness of vertical fins placed in the leeward plane of geometric symmetry and side strakes with different orientations is studied. For the active control, the effectiveness of normal and tangential flow injection and surface heating and a combination of these methods is studied

Sea Level Variation Along the Western Coast of the Arabian Gulf

Observed hourly tidal heights from six stations during the period 1980-1987 were used in the analyses. Daily readings of the pressure at mean sea level from three meteorological stations were also used. The variations of the observed daily mean sea level were studied at the six stations, giving low values in the winter season, and high ones in summer and spring seasons. The monthly mean sea level showed higher values during July and August and lower ones in the winter season. As the Arabian Gulf is generally considered a shallow sea, the meteorological conditions are the main cause of the sea level variation. This was shown by the variation of the daily mean sea level residual at the six stations. From the analyses of the coherence of several parameters, the pressure difference over the Gulf area did not give a noticeable effect with either the daily observed sea level or the daily sea level residual. Generally speaking, the important factor affecting the sea level variation in the Arabian Gulf is the pressure system covering the area either during the summer or the winter seasons

Effect of non-Hermiticity on adiabatic elimination in coupled waveguides

We investigate the influence of non-Hermiticity on the adiabatic elimination in coupled waveguides.We show that although the total norm of the system is not conserved in parity-time symmetric phase, the dark state intensity remains constant. However, in broken phase the eliminated waveguide loses its darkness, i.e., its field amplitude starts increasing. In both exact and broken phases, the effective Hamiltonian derived from the adiabatic elimination condition describes the dynamics of all states except the dark state. Specifically, it cannot predict the amplification in the intensity of the dark state. Our results can strengthen the control of the dynamics in cavities with active elements and improve the design of controllable absorbers

Pheno- and genotyping of Pasteurella multocida isolated from goat in Iran

In this study, phenotype, capsular type and some virulence factors (pfha1, tbpA, and toxA) of caprine Pasteurella multocida were described in 10 isolates from goat. Two biochemical biovars were recognized among the isolates based on dulcitol and sorbitol fermentation. The isolates belonged to biovars P. multocida sub. multocida (80%) and P. multocida sub. septica (20%). Capsular typing of isolates by PCR demonstrated two capsular types A (90%) and D. Among 3 virulence genes detected by PCR, we found a remarkable high prevalence of tbpA (80%) and toxA (70%) genes among caprine isolates. The high prevalence of these genes owning association of disease status among healthy animals showed high potential of the strains in induction of disease. The high prevalence of toxA and tbpA among goat is very similar to the ones in sheep isolates. Comparison of virulence genes profile showed possibility of P. multocida transmission between sheep and goat

Changes in Physico-Chemical Quality and Volatile Compounds of Orange-Carrot Juice Blends During storage

The present study aimed to determine the changes in physico-chemical parameters (pH, total soluble solids “TSS”, total acidity, vitamin C, total carotene, total phenolic and antioxidant activity) as well as sensory evaluation and volatile constituents of the orange juice samples mixed with carrot juice at ratios (1:3, 3:1 and 1:1). While, the polyphenol content was determined using Folin–Ciocalteu, antioxidant activity was measured using two in vitro assays 2,2'-diphenyl-1-picrylhydrazyl (DPPH0) and metal chelating assays. While, the acidity increased, total carotene and pH of the juice decreased during the storage period. There were no significant changes in total phenolics throughout the storage period at the three blending ratios. A slight increase in antioxidant capacity during the storage period had been observed. The headspace volatiles of fresh orange and carrot juices as well as fresh and stored blend juice with ratio (1:3) for 14 days at refrigerator were collected and subjected to Gas chromatography (GC) and Gas chromatography-Mass spectrometery (GC-MS) analysis. A total of 26 volatile compounds were identified in samples of fresh orange and carrot juices as well as fresh and stored blend including 7 alcohols, 4 aldehydes, 9 monoterpene hydrocarbon and 6 esters. Limonene was the one most abundant monoterpene, representing in orange, carrot, fresh and stored blend 47.38, 42.37, 39.24 and 37.25%, respectively. Keywords: Orange- carrot juice, Blend, Antioxidant, Volatile compound

Utility of Certain Nucleophilic Aromatic Substitution Reactions for the Assay of Ethamsylate in its Dosage forms and in Presence of its Degradation Product

The study represents the first report on the development of spectrophotometric methods for determination of ethamsylate (EST) in the presence of hydroquinone as an impurity and/or acidic degradation product. The proposed methods are based on the reaction of EST through it,s secondary amino group either with 1,2-naphthoquinone-4-sulphonate sodium (NQS) at pH 10.7 or 2,4-dinitrofluorobenzene (DNFB) at pH 9.3 to form orange and yellow colored reaction products peaking at 478 and 387 nm for methods (I) and (II), respectively. The different experimental parameters affecting the development and stability of the reaction products in methods (I) and (II) were carefully studied and optimized. The absorbance-concentration plots were rectilinear over the concentration ranges of 2-30 and 2-14 µg mL−1 for methods (I) and (II), respectively. The lower detection limits were 0.13 and 0.19 µg mL−1 and the lower quantitation limits were 0.44 and 0.63 µg mL−1 for methods (I) and (II), respectively. Both methods were successfully applied to commercial ampoules and tablets

Gustoća i viskoznost poluvodičkog spoja AgGaSe2 u čvrstom i tekućem stanju

The density and kinematic viscosity of AgGaSe2 were investigated in the solid and liquid states in the temperature range 690 - 930 °C. Density and dynamic viscosity measurements were carried out using the thermometer method and the rotating cylinder method. Experimental data show that the dependence of viscosity on temperature has an activation character and that logarithm of viscosity vs. reciprocal absolute temperature can be approximated by two straight lines corresponding to activation energies 0.36 eV and 0.19 eV in the solid and liquid states, respectively. The temperature dependence of the free volume was calculated and it was found that it decreases linearly with temperature. The results are explained on the basis of the free-volume model.Istraživali smo gustoću i kinematičku viskoznost AgGaSe2 u čvrstom i tekućem stanju na temperaturama 690 – 930 ◦C. U mjerenjima gustoće i viskoznosti primijenili smo termometrijsku metodu odnosno metodu rotirajućeg valjka. Mjerni podaci ukazuju da ovisnost viskoznosti η o temperaturi ima aktivacijske značajke, te se ovisnost log η o temperaturi može aproksimirati pravcima koji odgovaraju aktivacijskim energijama 0.36 eV and 0.19 eV za čvrsto odnosno tekuće stanje. Izveli smo i temperaturnu ovisnost slobodnog volumena i našli da se linerno smanjuje s temperaturom. Ishodi mjerenja tumače se na osnovi modela slobodnog volumena