New steps in acute coronary syndrome and antihyperlipidemic treatment: Determination of statins and metabolites by liquid chromatography tandem mass spectrometry

Our aim in this study was to develop a validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for the measurement of atorvastatin, rosuvastatin and their major metabolites, and furthermore to evaluate patients’ adherence to statin therapy and to investigate the effect of statin therapy on various hematological and biochemical parameters. A simple protein precipitation was performed for the extraction of analytes and the extracted samples were injected directly. The levels of drugs and their metabolites were measured by the validated method in a total of 210 patients diagnosed with unstable angina pectoris (USAP), ST-elevation myocardial infarction (STEMI) or non-ST-elevation myocardial infarction (NSTEMI). Various biochemical and hematological parameters were measured. The linearity ranges for atorvastatin and rosuvastatin were 1.22–2,500 and 0.97–2000 ng/ml, respectively. The inter-assay coefficient of variation for all analytes was ≤ 6%. In patients diagnosed with USAP, STEMI and NSTEMI, treatment compliance rates were 22.1, 23.5 and 41.2% for atorvastatin and 36.1, 40.2 and 67.1% for rosuvastatin, respectively. An economical, simple and reliable measurement method has been developed. Our findings support the poor patient compliance with statin therapy in the included population. It was observed that 6 months of statin treatment caused slight changes in biochemical and hematological parameters.     

Proton conductivity properties of acid doped fluoroalkylated 1,2,3-triazole

Novel proton conducting organic electrolyte containing fluoroalkylated 1,2,3-triazole was synthesized via intramolecular cyclisation of vinyl azides. FT-IR, elemental analysis and NMR methods were used for the characterization of the resulting organic molecule. Triazole containing sample was doped with triflic acid to obtain proton conducting organic electrolytes. Thermal stability of these materials was analyzed with thermogravimetric analysis (TGA) and the melting temperatures were measured by differential scanning calorimetry (DSC). The effect of acid content on the proton conductivity was investigated with impedance spectrometer and the maximum proton conductivity was measured as 10⁻² S/cm at 150 °C.     

Solid-core square-lattice photonic crystal fibers: comparative studies of the single-mode regime and numerical aperture for circular and square air-holes

In this paper we have studied solid-core square-lattice PCFs with circular and square shaped air-holes. We have estimated the V-parameter by using the step-index fiber approximation (SIFA) and calculated numerical apertures for the structures considered. In order to estimate the effective core radius of the structure with the square shaped air-holes we have used an approximation based on the air-filling fraction.     

Bypass transition through interactions of localized disturbances in wall-bounded flows

A new mechanism bypass in a wall-bounded internal flow is proposed and the proposal is checked by direct numerical simulations of high temporal and spatial resolution. The mechanism is based on the interactions of the localized perturbations, rather than the effect of a single perturbation investigated so far in the classical bypass transition process. It is first shown by theoretical considerations that two pairs of quasistreamwise vortices can interact near the wall in such a manner that the compression (stretching) of the existing wall-normal vorticity induced by one of the pairs can enhance a new streamwise vorticity zone that can lead to new coherent structures and enhance considerably the transition process. Direct numerical simulations confirm this hypothesis.     

Simulation of sonic boom interaction with shear turbulence

We investigate the interaction of pressure waves with the shear turbulence in a supersonic jet flow obtained from the direct numerical integration of the time-dependent, three-dimensional Euler equations. The resulting self-sustaining turbulent jet flow matches closely the relevant time and length scales of atmospheric turbulence. N-waves, characteristic of sonic booms, are simulated by perturbing the pressure profile and following these perturbations in space and time. The results reproduce most of the wave forms reported in laboratory experiments and in flight test data.     

Response of the streaks, the active and passive eddies in an unsteady channel flow

Spanwise space–time correlations of the wall shear stress and the longitudinal velocity fluctuations in the low buffer layer of an unsteady channel flow are reported. The imposed amplitude is 20% of the centerline velocity and the imposed frequency covers a large range going from the quasi-steady limit to the bursting frequency of the corresponding steady flow. The unsteady spanwise correlation coefficient is investigated both through its own modulation characteristics (amplitude and phase shifts) and those of the resulting streak spacing. A good correspondence is found between the modulation of the streak spacing and that of the ejection period. The data is further analyzed by temporal filtering of the wall shear stress and streamwise velocity fluctuations. It is shown that the large outer-layer structures play a “passive” role in the unsteady response of the near wall turbulence. The inner wall eddies, in return, are amply responsible for the unsteady reaction of both the turbulent wall shear stress and the streamwise velocity intensities in the buffer layer.     

On the application of pseudospectral FFT techniques to non-periodic problems

The reduction-to-periodicity method using the pseudospectral fast Fourier transform (FFT) technique is applied to the solution of non-periodic problems, including the two-dimensional incompressible Navier–Stokes equations. The accuracy of the method is explored by calculating the derivatives of given functions, one- and two-dimensional convective-diffusive problems, and by comparing the relative errors due to the FFT method with a second-order finite difference (FD) method. Finally, the two-dimensional Navier–Stokes equations are solved by a fractional step procedure using both the FFT and the FD methods for the driven cavity flow and the backward-facing step problems. Comparisons of these solutions provide a realistic assessment of the FFT method.     

Synthesis,structural characterization and antimicrobial activities of cyclochlorotriphosphazene derivatives derived from N-(1-Naphthyl)ethylenediamine

Abstract

The nucleophilic substitution reactions of cylochlorotriphosphazene (N₃P₃Cl₆) with N-(1-Naphthyl)ethylenediamine resulted in the following formation of partially and fully substituted cyclotriphosphazene derivatives: 2,4,4,6,6-pentachloro-2-open-chain-N-(1-Naphthyl) ethylendiamino-cyclotriphosphazatriene (3); 4,4,6,6-tetrachloro-2,2-spiro-N-(1-Naphthyl) ethylendiamino-cyclotriphosphazatriene (4); 2,6,6-trichloro-2-open-chain-4,4-spiro-N-(1-Naphthyl)ethylendiamino-cyclotriphosphazatriene (5); 2,4-dichloro-2,4-ansa-6,6-spiro-N-(1-Naphthyl)ethylendiamino)-cyclotriphosphazatriene (6); and 2,4,6-trichloro-2,4,6-non-gem-open-chain-N-(1-Naphthyl)ethylendiamino)-cyclotriphosphazatriene (7); 2,2,4,4,6,6-tri-spiro-N-(1-Naphthyl)ethylendiamino)-cyclotriphosphazatriene (8); 2,4-dichloro-2,4-cis-open-chain-6,6-spiro-N-(1-Naphthyl)ethylendiamino)-cyclotriphosphazatriene (9); and 2,4,6,6-tetrachloro -2,4-ansa-N-(1-Naphthyl)ethylendiamino)-cyclotriphosphazatriene (10). The reactions produced the 4,4,6,6-tetrachloro-2,2-spiro-N-(1-Naphthyl) ethylendiamino-cyclotriphosphazatriene (4) and 2,4,6,6-tetrachloro-2,4-ansa-N-(1-Naphthyl)ethylendiamino)-cyclotriphosphazatriene (10) derivatives as the major products in this system. The structures of the compounds were characterized by FT-IR, elemental analysis, TLC-MS, FT-IR, ¹H, and ³¹P NMR spectral data. All the derived compounds (3–10) were screened for antimicrobial activity by using the broth-agar microdilution technique for the determination of MIC and MCC values. In this context, the compounds were examined against three different human pathogens; Escherichia coli W3110, Staphylococcus aureus ATCC 25923 and Candida albicans ATCC 10231. Except compounds 6 and 9, the rest of the compounds exhibited significant antimicrobial activity on E. coli (W3110), S. aureus (ATCC 25923) and C. albicans (ATCC 1023). Among the synthesized derivatives, compound 4 is the most active agent against the referenced bacteria.     

The electric double layer effect on the microchannel flow stability and heat transfer

The effect of the electric double layer (EDL) on the linear stability of Poiseuille planar channel flow is reported. It is shown that the EDL destabilises the linear modes, and that the critical Reynolds number decreases significantly when the thickness of the double layer becomes comparable with the height of the channel. First results coming from direct numerical simulations on the non-linear effects show also that the by-pass transition is much more rapid in the presence of EDL. There is an acceptable qualitative correspondence between the estimated transitional Reynolds numbers and some experiments, showing that early transition is plausible in microchannels under some conditions. Several questions remain however unanswered such as the surface conduction effect on EDL.