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921.
Quantitative study on La~(3+) influx mediated by sodium-calcium exchanger in human lymphocytes 总被引:2,自引:0,他引:2
Whether La3+ can enter human peripheral blood lymphocytes by the Na+/Ca2+ exchanger or not and the effect of La3+on the Na+/Ca2+ exchanger activity are examined by fura-2 technique. And that whether La3+ is sequestered by intracellular organelles (mainly endoplasmic reticulum and mitochondria) is studied by this method. La3+uptake is obviously stimulated by pre-treating the cells with ouabain and by removing extracellular Na+, and intracellular La3+concentration ([La3+]i) is directly proportional to its extracellular concentration ([La3+]o). But when [La3+]o exceeds 0.4 mmol/L, the 340/380 nm ratio of fluorescence is no longer varied and the maximum [La3+], is 1.5×10-12 mol · L-1. The higher concentration of La3+ (0.1 mmol/L) increases Na+/Ca2+ exchange-mediated calcium influx, but lower concentration (10 μmol/L) appears to block calcium influx. The results also suggest that cytosolic La3+ is transported by the ATP-dependent Ca2+ pump. Intracellular Ca2+ stores are depleted by ionomycin, and then ion 相似文献
922.
1,4-Disubstituted 1,2,3-triazoles are obtained in excellent yields via a three-component coupling of secondary alcohols, alkynes and trimethylsilyl azide (TMSN3). This one-pot reaction occurs through in situ generation of an azide from the alcohol and TMSN3, followed by 1,3-dipolar cycloaddition of the terminal alkyne to afford the corresponding disubstituted triazoles. 相似文献
923.
B. A. Arbuzov Z. G. Isaeva M. G. Belyaeva V. V. Ratner O. N. Kataeva I. A. Litvinov V. A. Naumov 《Russian Chemical Bulletin》1992,41(1):117-119
Oxidation of 2-carene by lead tetraacetate in acetic acid afforded p-menth-1(10),2-dien-7-ol, 2-acetyl-6,6-dimethylbicyclo[3.1.0]hexane, p-menth-2-ene-1,7-diol, p-menth-1-ene-3,7-diol, and 2-(m-tolyl)propanol-2.Deceased.A. M. Butlerov Scientific Research Chemical Institute, V. I. Ul'yanov-Lenin Kazan' State University, 420008 Kazan. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 147–150, January, 1992. 相似文献
924.
V. Kornas V. Schulz-von der Gathen T. Bornemann H. F. Döbele G. Prosz 《Plasma Chemistry and Plasma Processing》1991,11(2):171-184
The application of coherent anti-Stokes Raman spectroscopy (CARS) to an electric are test reactor is described in which acetylene synthesis in analogy to the large-scale industrial process is .studied. We report on spatially resolved measurements of H2-CARS spectra, the comparison with calculated spectra, and the determination of temperatures in the reaction zone.Dedicated to Prof. Rudolf Wienecke on the occasion of his 65 birthday. 相似文献
925.
微分方法在聚苯骈咪唑修饰电极溶出伏安分析研究中的应用 总被引:2,自引:0,他引:2
本文推导了聚苯骈咪唑修饰电极溶出伏安分析中电流对电位的二次方程,并以Fe(C2O4)^2-3为研究对象,对该方程进行了实验验证,实验结果与理论相吻合。 相似文献
926.
927.
928.
Liliana Viciu 《Journal of solid state chemistry》2003,175(1):88-93
Mn-Cl sheets were inserted into the perovskite blocks of a double-layered Dion-Jacobson compound by ion exchange at low temperature (390°C). The Rietveld structural analysis of X-ray powder diffraction data (P4/mmm) indicates that the product, (MnCl)LaNb2O7, has the manganese coordinated by two apical oxygens from the perovskite layers and four in-plane chlorines within the interlayer space. On heating, this compound exhibits an exothermic transition between 650°C and 750°C that is consistent with metastability. Magnetic characterization shows Curie-Weiss behavior at higher temperatures (>200 K) with a magnetic moment corresponding to the presence of high-spin Mn2+ ion (S=5/2). At lower temperatures, antiferromagnetic interactions become significant and the broad maximum at 63 K reveals the 2-D character of the magnetic behavior. The susceptibility data, fit with the high temperature expansion for a Heisenberg square planar system, show a negative exchange interaction of J/k=−3.77 K. 相似文献
929.
以Mn2O3和氢氧化锂为原料,通过焙烧合成出o-LiMnO2。用X射线衍射和扫描电镜对不同温度下合成的粉末样品进行了表征,并研究了材料的电化学性能。通过对不同温度条件下烧结样品的晶胞参数、布拉格(110)晶面峰半高宽及电化学性能研究发现:600 ℃下合成样品的半高宽最大,堆垛层错率高,同时电化学性能也最好,首次放电容量达到156 mAh·g-1,20次循环后仍保持在140 mAh·g-1以上。中高温固相合成的o-LiMnO2材料,在晶粒范围大小相近时,材料电化学性能与材料堆垛层错率相关。 相似文献
930.