Photoluminescence of undoped and B-doped ZnO in silicate glasses

Photoluminescence of undoped and B-doped ZnO in silicate glasses was investigated by varying the concentration of ZnO (3550 mol%) and B dopant (0-10 mol%) in the glass matrices. The broad and intense near band edge emissions were observed while the visible light emission was very weak. UV luminescence in all samples was red-shifted relative to the exciton transition in bulk ZnO and enhanced by decreased ZnO concentration due to higher degree of structural integrity and the lower aggregation degree of ZnO. Donor B dopant played the double roles of filling conduction bands to broaden band gap when its concentration was lower than 5 mol%, and emerging with conduction bands to narrow the gap when B dopant exceeded this value. (c) 2007 Elsevier B.V. All rights reserved.

Anti-HIV-1 Activities of Hemslecins A and B

目的:研究从药用植物金佛山雪胆分离的雪胆素A和雪胆素B两个三萜类化合物的体外抗HIV活性.方法:应用合胞体抑制实验、p24抗原产生的抑制实验、慢性感染细胞和正常细胞间的细胞融合抑制实验等技术检测化合物的体外抗HIV-l活性;利用HIV-l逆转录酶、蛋白酶抑制实验,NCp7锌离子逐出实验探讨化合物的作用机制.结果:雪胆素A和雪胆素B在体外有较好的抑制HIV-l活性,其活性主要表现为:(1)抑制HIV-l诱导合胞体形成,EC50值分别为3.09 μg·mL-1和2.53μg·mL-1;(2)抑制HIV- 急性感染的C8106细胞p24抗原产生,EC50值分别为3.97μg·mL-1和18.90μg·mL-1;(3)抑制HIV-1 慢性感染H9与正常C8166细胞间融合,EC50分别为1.76μg·mL-1和11.95μg·mL-1.雪胆素A和雪胆素B对HIV-l逆转录酶、蛋白酶、NCp7锌离子逐出均没有抑制作用.雪胆素A对HIV-1整合酶有微弱的结合活性,而雪胆素B对HIV-1整合酶没有结合活性.在共培养实验中,雪胆素A和雪胆素B预处理C8166细胞组比未经预处理细胞组能够更有效的抑制HIV-l活性.结论:化合物雪胆素A和雪胆素B体外有较好的抗HIV-1活性,可能主要作用于HIV-1病毒进入细胞阶段.

Dichotomains A and B: Two new highly oxygenated phenolic derivatives from Dicranopteris dichotoma

Dichotomains A (1) and B (2), two new highly oxygenated phenolic derivatives that feature a spirodilactone moiety in their structures, were isolated from the fronds of Dicranopteris dichotoma. Their structures were elucidated on the basis of NMR and MS sp

Sphenadilactones A and B, two novel nortriterpenoids from Schisandra sphenanthera

Two novel nortriterpenoid compounds, sphenadilactones A (1) and B (2), have been isolated from the leaves and stems of Schisandra sphenanthera. The structural elucidation of 1 and 2 was accomplished by extensive NMR analysis. The relative stereochemistry

Rubriflordilactones A and B, two novel bisnortriterpenoids from Schisandra rubriflora and their biological activities

Rubriflordilactones A (1) and B (2), two novel highly unsaturated rearranged bisnortriterpenoids possessing a biosynthetically modified aromatic D-ring, were isolated from the leaves and stems of Schisandra rubriflora. Their structures were established on

Schilancidilactones A and B: two novel tetranortriterpenoids with an unprecedented skeleton from Schisandra lancifolia

Schilancidilactones A (1) and B (2). two novel tetranortriterpenoids possessing an unprecedented skeleton, have been isolated from the stems of Schisandra lancifolia. Their structures were elucidated on the basis of extensive spectroscopic analysis. The r

Measurement of the total reaction cross section for the mirror nuclei N-12 and B-12

The mirror nuclei N-12 and B-12 are separated by the Radioactive Ion Beam Line in Lanzhou (RIBLL) at HIRFL from the breakup of 78.6 MeV/u N-14 on a Be target. The total reaction cross-sections of N-12 at 34.9 MeV/u and B-12 at 54.4 MeV/u on a Si target have been measured by using the transmission method. Assuming N-12 consists of a C-11 core plus one halo proton, the excitation function of N-12 and B-12 on a Si target and a C target were calculated with the Glauber model. It can fit the experimental data very well. The characteristic halo structure for N-12 was found with a large diffusion of the protons density distribution.

Chinikomycins A and B: Isolation, structure elucidation, and biological activity of novel antibiotics from a marine Streptomyces sp isolate M045

In our screening of marine Streptomycetes for bioactive principles, two novel antitumor antibiotics designated as chinikomycins A (2a) and B (2b) were isolated together with manumycin A (1), and their structures were elucidated by a detailed interpretation of their spectra. Chinikomycins A (2a) and B (2b) are chlorine-containing aromatized manumycin derivatives of the type 64-pABA-2 with an unusual para orientation of the side chains. They exhibited antitumor activity against different human cancer cell lines, but were inactive in antiviral, antimicrobial, and phytotoxicity tests.

Effects of pure microcystin-LR on the transcription of immune related genes and heat shock proteins in larval stage of zebrafish (Danio rerio)

Microcystins (MCs) are cyanobacterial toxins in water blooms that have received increasing attention as a public biohazard for human and animal health. Previous studies were mainly focused on the toxic effects on adult fish, rather than juvenile or larvae, and the response of fish immune system were usually neglected. This paper presents the first data of the effects of microcystin-LR (MC-LR) on transcription of several genes essential for early lymphoid development (Rag1, Rag2, Ikaros, GATA1, Lck and TCR alpha) and heat shock proteins (HSP90, HSP70, HSP60, HSP27) in zebrafish larvae. Relative changes of mRNA transcription were analyzed by real time PCR. The transcription of Rag1, Rag2, Ikaros, GATA1, Lck and TCR alpha were up-regulated when following exposure to 800 mu g/L MC-LR, which may indicate that specific lymphocytes differentiation and TCR/lg arrangement are induced to counteract the toxic effects of MC-LR. It was also interesting to note the dramatically increased transcription of HSP90. HSP70, HSP60 and HSP27, which may indicate their important roles as molecular chaperones under oxidative stress. (C) 2009 Elsevier B.V. All rights reserved.

The effect of substrate orientation on the morphology of InAs nanostructures on (001) and (11n)A/B(n=1-5) InP substrates

Strained InAs nanostructures have been grown by solid-source molecular beam epitaxy in In0.52Al0.48As matrix on different InP substrate surfaces ((0 0 1) and (1 1 n)A/B (n = 1 - 5)). The morphology of the nanostructures was characterized using atomic force microscopy (AFM). The AFM results reveal interesting differences in the size, shape, and alignment of the nanostructures between different oriented surfaces. It was found that some faceted nanostructures tend to form on A-type surfaces, the shape and the alignment of these nanostructures show clear dependence on the substrate orientation. Samples grown on (0 0 1) and B-type surfaces showed preferentially dense round dots. Dots formed on (1 1 3)B, (1 1 3)B and (1 1 5)B surfaces have a higher dot density and size homogeneity, which shows a potential for the production of high-quality and customized self-assembled quantum dots for photonics applications. (C) 2000 Elsevier Science B.V. All rights reserved.

The Influence of Age and Sex on the Cell Counts of Peripheral Blood Leukocyte Subpopulations in Chinese Rhesus Macaques

therapeutic drugs, vaccines and mechanisms of human diseases. Little is known about the normal levels of leukocyte subpopulations of Chinese rhesus macaques. To obtain these data, 100 blood samples from Chinese rhesus macaques were collected. The normal range of major leukocyte subpopulations, such as T lymphocytes, B lymphocytes, monocytes, myeloid dendritic cells (mDCs) and plasmacytoid dendritic cells (pDCs), were quantitatively analyzed by flow cytometry through BD trucount tubes. The influence of age and sex on the cell counts of leukocyte subpopulations was analyzed. The counts of CD3+ T cells, CD3+CD4+ T cells, CD3+CD8+ T cells and B cells decreased with age, but those of monocytes, mDCs and pDCs had no significant correlation with age. Significant differences existed in the cell counts of most leukocyte subpopulations between the male and female groups except pDCs. Furthermore the values of the females were higher than those of the males. The study provided basic information about the leukocyte subpopulations of Chinese rhesus macaques, and it may be valuable for immunobiological study of Chinese rhesus macaques. Cellular & Molecular Immunology. 2009;6(6):433-440.