八种稀土金属配合物和铂配合物抗HIV 活性的研究

　为了寻找治疗艾滋病的新药,研究了8 种稀土金属(镧、铒、镝、钆、镨、镱、钐、钕) 配合物和铂 配合物的抗HIV 活性。我们以C8166 细胞系为指示细胞,测定样品对HIV - 1IIIB诱导的细胞合胞体形成 的抑制作用,并以MTT方法测定它们对细胞存活率的影响,以研究稀土和铂配合物对细胞的毒性。根 据公式,计算出其CC50和EC50值,并进一步计算出其TI 值。结果表明,镧配合物、钐配合物和铂配合物 的EC50值分别为0. 006μg/ ml 、74. 28μg/ ml 和21. 54μg/ ml ,它们的治疗指数分别为63、21 和45 ,具有一定的 抗HIV - 1 活性。其它的配合物具有很低或者不具有抗HIV - 1 活性。

Design of shallow acceptors in ZnO through compensated donor-acceptor complexes: A density functional calculation

The intrinsic large electronegativity of O 2p character of the valence-band maximum (VBM) of ZnO renders it extremely difficult to be doped p type. We show from density functional calculation that such VBM characteristic can be altered by compensated donor-acceptor pairs, thus improve the p-type dopability. By incorporating (Ti+C) or (Zr+C) into ZnO simultaneously, a fully occupied impurity band that has the C 2p character is created above the VBM of host ZnO. Subsequent doping by N in ZnO: (Ti+C) and ZnO: (Zr+C) lead to the acceptor ionization energies of 0.18 and 0.13 eV, respectively, which is about 200 meV lower than it is in pure ZnO.

SPECTROSCOPIC INVESTIGATION OF HYDROGEN-DOPANT COMPLEXES IN BULK P-TYPE AND IMPLANTED N-TYPE CRYSTALLINE SILICON

Infrared absorption experiments have been performed on hydrogenated and deuterated bulk boron- and aluminum-doped-Si and implanted P, As, and Sb donors in silicon. A first evidence of complex formation in bulk p-type Si is obtained and the spectra confirm the anomalous 3.3-cm-1 deuterium frequency shift with respect to boron isotopes. The ratio of the D-B-11 and D-B-10 peak areas is found to be the same as that of the two boron isotopes natural abundance. In donor-implanted silicon, a quantitative analysis of the obtained data has allowed a rough estimate of the passivating rate due to diffusing deuterium. While the frequencies of the various vibrational lines are found to be in agreement with those reported in the literature, the data on the broad line at 1660 cm-1 (H) or 1220 cm-1 (D) seem to suggest an assignment of this peak to a complex in the bulk involving some type of defect due to the implantation process.