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1.
A sensitive and selective method was developed for the determination of (R)-ketoprofen ((R)-kt) and (S)-ketoprofen ((S)-kt) in human plasma using chiral liquid chromatography/tandem mass spectrometry (LC/MS/MS). Plasma samples spiked with stable-isotope-labeled [(13)C(1), (2)H(3)]-(R and S)-ketoprofen, for use as the internal standards, were prepared for analysis using automated solid-phase extraction (SPE) in the 96-well microtiter format. The enantiomers were separated on an (R)-1-naphthylglycine and 3,5-dinitrobenzoic acid (Chirex 3005) 250x2.0 mm i.d. analytical column, equipped with a 30x2.0 mm i.d. guard column using isocratic mobile phase conditions. The (R)- and (S)-kt levels were quantifiable from 0.05 to 2500 ng ml(-1) by constructing two separate curves from calibration standards covering the same range. The first curve ranged from 0.05 to 100 and the second from 100 to 2500 ng ml(-1). A concentration of 0.05 ng ml(-1) of either enantiomer was easily detected using a 1 ml plasma sample volume. The average method accuracy, evaluated at four levels over an extended period, was better than +/-3% over the entire range. The precision for the same set of quality control samples ranged from 4.0 to 7.0 % RSD (n = 24). The method was applied to the evaluation of pharmacokinetic parameters in human plasma obtained from volunteers who received 25 mg of kt by peroral administration of Actron caplets or by topical administration of Oruvail gel. 相似文献
2.
The effects of crystallographic orientation on output amplitude and signal-dependent phase distortions in electrooptic spatial light modulators such as the PROM and PRIZ are described. 相似文献
3.
Laevorotatory crystals of isomorphous Bi12SiO20 and Bi12GeO20 are shown, by use of the anomalous X-ray scattering component in the structure amplitudes, to have identical chirality (handedness of atomic arrangement) in contrast with the case of NaC103 and NaBrO3, in which crystals of the same chirality rotate plane polarized light in opposite senses. 相似文献
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The buffer layer of an internal flow manipulated by riblets is investigated. The distributions of the ejection and bursting frequency from the beginning to the middle part of the buffer layer, together with high moments of the fluctuating streamwise velocity,u, and its time derivative are reported. The profiles of the ejection and bursting frequency are determined and compared using three single point detection schemes. The effect of the riblets on the bursting mechanism is found confined in a localized region in the buffer layer. The multiple ejection bursts are more affected than the single ejection bursts. The skewness and flatness factors of theu signal are larger in the manipulated layer than in the standard boundary layer. That, also holds true for the flatness factor of the time derivative, but the Taylor and Liepman scales are not affected. The spectrum of theu signal is altered at the beginning part of the viscous sublayer.Nomenclature
u
Friction velocity
-
Viscosity
-
l
v
;f
v
wall scalesv/u
;u
2
/v
-
y
Vertical distance to the wall
- z
Spanwise extent
- (+)
Variable normalized with wall scales
-
u
Velocity;u=Turbulence intensity
-
h, s
Height and width of the riblets
-
f
e
Ejection frequency
-
f
b
Bursting frequency
-
f
BME
Frequency of the Bursts with Multiple Ejection
-
f
BSE
Frequency of Single Ejection Bursts
-
S
andS
du/dt
Skewness factor ofu and its time derivative
-
F
u
andF
du/dt
Flatness factor ofu and its time derivative
Abbreviations SBL
Standard (non-manipulated) Boundary Layer
- MBL
Manipulated Boundary Layer
- BME
Bursts with Multiple Ejections
- BSE
Bursts with Single Ejections
- VITA
Variable Interval Time Averaging technique
-
u–l
u-level technique
-
mu
Modifiedu-level technique 相似文献
6.
ZDM – Mathematics Education - The theoretical and methodological model of Mathematical Working Space (MWS) is introduced in this paper. For over 10 years, the model has been the... 相似文献
7.
The sequential detonation of a layer of explosive surrounding a pressurized tube can be used to generate fast, high-density
shock waves by means of a piston-like implosive pinch travelling at the detonation velocity of the explosive. A novel technique
has been developed to extend the regime of operation to piston velocities greater than the detonation velocity of known explosives.
This technique consists of cutting a slit in the tamper of a conventional explosive shock tube and introducing a phased detonation
wave into the explosive cladding. Preliminary results indicate that quasi-steady shocks can be generated in helium with velocities
between 13–17 km/s for initial fill pressures of 6.9 MPa. 相似文献
8.
SL Mironov E Skorova G Taschenberger N Hartelt VO Nikolaev MJ Lohse S Kügler 《BMC neuroscience》2009,10(1):29-11
Background
cAMP is an ubiquitous second messenger mediating various neuronal functions, often as a consequence of increased intracellular Ca2+ levels. While imaging of calcium is commonly used in neuroscience applications, probing for cAMP levels has not yet been performed in living vertebrate neuronal tissue before. 相似文献9.
PF Hendrix SL Lachnicht MA Callaham X Zou 《Rapid communications in mass spectrometry : RCM》1999,13(13):1295-1299
Feeding strategies of earthworms and their influence on soil processes are often inferred from morphological, behavioral and physiological traits. We used (13)C and (15)N natural abundance in earthworms, soils and plants to explore patterns of resource utilization by different species of earthworms in three tropical ecosystems in Puerto Rico. In a high altitude dwarf forest, native earthworms Trigaster longissimus and Estherella sp. showed less (15)N enrichment ((15)N = 3-6 per thousand) than exotic Pontoscolex corethrurus ((15)N =7-9 per thousand) indicating different food sources or stronger isotopic discrimination by the latter. Conversely, in a lower altitude tabonuco forest, Estherella sp. and P. corethrurus overlapped completely in (15)N enrichment ((15)N = 6-9 per thousand), suggesting the potential for interspecific competition for N resources. A tabonuco forest converted to pasture contained only P. corethrurus which were less enriched in (15)N than those in the forest sites, but more highly enriched in (13)C suggesting assimilation of C from the predominant C(4) grass. These results support the utility of stable isotopes to delineate resource partitioning and potential competitive interactions among earthworm species. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
10.
Bismuth silicon oxide (Bi12SiO20) exhibits several unique characteristics for application to various optical devices, including the Pockels Readout Optical Memory (PROM), photorefractive read-write holographic memory, and thin film optical waveguides. These applications place stringent requirements on the optical quality of the material. A number of difficulties associated with Czochralski growth of optical quality Bi12SiO20 are discussed, including photochromic effects, selective decoration, growth striations, refractive index homogeneity, and strain-induced birefringence. The photochromic decoration effect is shown to exhibit selectivity between polar antipodes as well as crystallographic orientations. 相似文献