Propofol and Aminophylline Antagonize Each Other During the Mobilization of Intracellular Calcium in Human Umbilical Vein Endothelial Cells

This study examined whether propofol and aminophylline affect the mobilization of intracellular calcium in human umbilical vein endothelial cells. Intracellular calcium was measured using laser scanning confocal microscopy. Cultured and serum-starved cells on round coverslips were incubated with propofol or aminophylline for 30 min, and then stimulated with lysophosphatidic acid, propofol and aminophylline. The results were expressed as relative fluorescence intensity and fold stimulation. Propofol decreased the concentration of intracellular calcium, whereas aminophylline caused increased mobilization of intracellular calcium in a concentration-dependent manner. Propofol suppressed the lysophosphatidic acid-induced mobilization of intracellular calcium in a concentration-dependent manner. Propofol further prevented the aminophylline-induced increase of intracellular calcium at clinically relevant concentrations. However, aminophylline reversed the inhibitory effect of propofol on the elevation of intracellular calcium by lysophosphatidic acid. Our results suggest that propofol and aminophylline antagonize each other on the mobilization of intracellular calcium in human umbilical vein endothelial cells at clinically relevant concentrations. Serious consideration should be given to how this interaction affects mobilization of intracellular calcium when these two drugs are used together

LKZ-1: A New Zircon Working Standard for the In Situ Determination of U–Pb Age, O–Hf Isotopes, and Trace Element Composition

This study introduces a new zircon reference material, LKZ-1, for the in situ U–Pb dating and O–Hf isotopic and trace element analyses. The secondary ion mass spectrometric analyses for this gem-quality single-crystal zircon yielded a weighted mean 206Pb/238U age of 572.6 ± 2.0 Ma (2σ, n = 22, MSWD = 0.90), with moderately high U concentrations (619 ± 21 ppm, 1 SD), restricted Th/U ratios (0.146 ± 0.002, 1 SD), and negligible common Pb content (206Pbc < 0.2%). A comparable 206Pb/238U age (570.0 ± 2.5 Ma, 2σ) was produced by the isotope dilution-thermal ionization mass spectrometry. The secondary ion mass spectrometric and laser ablation-assisted multiple collector inductively coupled plasma mass spectrometer analyses respectively showed that LKZ-1 had little variation in O (δ18OV-SMOW = 10.65 ± 0.14‰; laser fluorination value = 10.72 ± 0.02‰; 1 SD) and Hf (176Hf/177Hf = 0.281794 ± 0.000016, 1 SD) isotopic compositions. LKZ-1 was also fairly homogeneous in its chemical composition (RSD of laser ablation ICPMS data ≤ 10%), displaying a relatively uniform chondrite-normalized rare earth element pattern ((Lu/Gd)N = 31 ± 3, Eu/Eu* = 0.43 ± 0.17, Ce/Ce* = 44 ± 32; 1 SD). These consistencies suggest that the LKZ-1 zircon is a suitable working standard for geochronological and geochemical analyses

Busan port's development into a Northeast Asian hub-port & 「the Korea-Japan strait economic Bloc」

노트 : 2008 Proceedings of The 6th International Joint Conferenc

Calibration of Sm-Nd mixed spike by teflon powder method

Isotopic composition of Sm-Nd mixed spike was calibrated by teflon powder method. Sm and Nd isotopic compositions of the spike were externally calibrated with reference to the nNdβ standard and normal Sm. Sm and Nd concentrations in the mixed spike were determined by isotope dilution protocol. Sm and Nd were separated by teflon powder method from the mixture of the spike with an interlaboratory standard (CIT Sm-Nd standard). We confirmed that precise Sm/Nd ratio (< 0.1 % error) and undisturbed Nd isotopic composition can be measured at the same time on condition that the sample to spike ratio is optimized. Garnet from the shear zone between the Gyeonggi massif and the Imjingang belt (Gyeonggi shear zone) was dated as a practical test of our experimental procedure. The Sm-Nd data of garnet, K-feldspar and whole rock samples from the shear zone define an Early Proterozoic age of 1730±71 Ma, indicating that Sm-Nd system of the garnet was not disturbed during Triassic deformation

SHRIMP allanite U-Th-Pb dating of bimodal Triassic metamorphism of Neoarchean tonalitic gneisses, Daeijak Island, central Korea

The microstructures, compositions and U-Th-Pb ages of allanite from tonalitic gneisses in a Neoarchean migmatite complex, Daeijak Island, central Korea, have been investigated. Allanite crystals up to ∼300 μm in diameter occur with accessory apatite,

Radiogenic and stable isotope measurement using a MC-ICP-MS

In this study, we presented newly developed analytical methods for radioactive, radiogenic, and stable isotopes using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS), where the elemental purification, and precision and accuracy were highlighted

Matrix contribution of environmental swipe materials for safeguard to uranium isotopic measurement

In order to investigate and quantify uranium content and isotope ratios in environmental swipe materials itself, the determinations of uranium isotope ratios in cotton swipes as well as working standard solutions are performed using multi collector inductively coupled plasma mass spectrometer (MC-ICPMS) and thermal ionization mass spectrometer (TIMS). We found that co-existing uranium in the swipes causes a serious shift of the measured data from the certified values. This study highlights the importance of mass balance correction for a precise uranium isotopic measurement of environmental swipe materials