Fluorescence properties and laser demonstrations of Nd-doped high silica glasses prepared by sintering nanoporous glass

Porous glass with high-SiO2 content was impregnated with Nd ions, and subsequently sintered at 1100 degrees C into a compact non-porous glass in air or reducing atmosphere. Sintering in a reducing atmosphere produced an intense violet-blue fluorescence at 394 nm. However, the sintering atmospheres almost did not affect the fluorescence properties in the infrared range. A good performance Nd3+-doped silica microchip laser operating at 1064 nm was demonstrated. The Nd-doped sintering glasses with high-SiO2 content are potential host materials for high power solid-state lasers and new transparent fluorescence materials. (c) 2007 Elsevier B.V. All rights reserved.

Blue green emission from a Cu+-Doped transparent material prepared by sintering porous glass

A colorless transparent, blue green emission material was fabricated by sintering porous glass impregnated with copper ions. The emission spectral profile obtained from Cu+ -doped high silica glass (HSG) by 267-mn monochromatic light excitation matches that obtained by pumping with an 800-nm femtosecond laser, indicating that the emissions in both cases come from an identical origin. The upconversion emission excited by 800-nm femtosecond laser is considered to be a three-photon excitation process. A tentative scheme of upconverted emission from Cu+ -doped HSG was also proposed. The glass materials presented herein are expected to find application in lamps, high density optical storage, and three-dimensional color displays.

Preparation and spectroscopic properties of Er3+-doped high silica glass fabricated by sintering nanoporous glass

A compact nonporous high silica (SiO2 % > 96%) glass containing 3400 ppm Er3+ ions, which was about ten times higher than that in Er-doped silica fiber amplifier (EDSFA), was synthesized by sintering porous glass immersed into erbium nitrate solution. The 1532 nm fluorescence has a FWHM (Full Width at Half Maximum) of 45 nm wider than that of EDSFA and possesses the glass with potential application in broadband fiber amplifiers. The Judd-Ofelt theoretical analysis reflects that Er3+ ions are located in a higher covalent environment which are comparable to those of aluminosilicate glass. (c) 2005 Elsevier B.V. All rights reserved.

Spectroscopic properties of Nd3+-doped high silica glass prepared by sintering porous glass

A new kind of Nd3+, -doped high silica glass (SiO2 > 96% (mass fraction)) was obtained by sintering porous glass impregnated with Nd3+, ions. The absorption and luminescence properties of high silica glass doped with different Nd3+, concentrations were studied. The intensity parameters Omega(t) (t = 2, 4, 6), spontaneous emission probability, fluorescence lifetime, radiative quantum efficiency, fluorescence branching ratio, and stimulated emission cross section were calculated using the Judd-Ofelt theory. The optimal Nd3+ concentration in high silica glass was 0.27% (mole fraction) because of its high quantum efficiency and emission intensity. By comparing the spectroscopic parameters with other Nd3+ doped oxide glasses and commercial silicate glasses, the Nd3+-doped high silica glasses are likely to be a promising material used for high power and high repetition rate lasers.

High quantum efficiency and high concentration erbium-doped silica glasses fabricated by sintering nanoporous glasses

A new method was used to prepare erbium-doped high silica (SiO2% > 96%) glasses by sintering nanoporous glasses. The concentration of erbium ions in high silica glasses can be considerably more than that in silica glasses prepared by using conventional methods. The fluorescence of 1532 nm has an FWHM (Full Wave at Half Maximum) of 50 nm, wider than 35 nm of EDSFA (erbium-doped silica fiber amplifer), and hence the glass possesses potential application in broadband fiber amplifiers. The Judd-Ofelt theoretical analysis reflects that the quantum efficiency of this erbium-doped glass is about 0.78, although the erbium concentration in this glass (6 x 103) is about twenty times higher than that in silica glass. These excellent characteristics of Er-doped high silica glass will be conducive to its usage in optical amplifiers and microchip lasers.

Rare-earth-doped silica microchip laser fabricated by sintering nanoporous glass

We report a new method for fabricating rare-earth-doped silica glasses for laser materials obtained by sintering nanoporous silica glasses impregnated with rare-earth-doped ions. The fabricated materials have no residual pores and show good optical and mechanical properties. Good performance from a Nd3+-doped silica microchip laser operating at 1.064 mum is successfully demonstrated, suggesting that the fabricated silica glasses have potential for use as active materials for high-power solid-state lasers. (C) 2005 Optical Society of America.

AIDS 免疫治疗相关腺病毒载体的构建

艾滋病（AIDS）是人类免疫缺陷病毒（HIV）感染后引起的一种严重危害人类健 康的致死性传染病。抗HIV 药物挽救和延长了很多HIV 感染者的生命，提高了其生活 质量，但是仍然不能治愈AIDS 和预防传播。最终有效控制HIV 传播和感染的方法可能 仍将依赖于HIV 疫苗的应用。HIV 感染对感染者以及社会造成的灾难性后果使得发展 一个有效的艾滋病疫苗变得尤为紧迫和重要。 负载HIV-1 抗原的DC 回输到HIV-1 感染者体内可以诱导产生较强的抗HIV-1 细 胞免疫反应，这种免疫反应理论上和临床试验都表明治疗AIDS 有效，而且对HARRT 治疗能够产生很好的协同作用。我们拟用感染了重组腺病毒的DC，回输到HIV-1 感染 者体内，期望可以较好地控制病毒复制和阻止感染。为此，本研究我们制备了重组腺病 毒vAd-gp140、vAd-tat 和vAd-gp140-tat，为后续研究奠定基础。 结构蛋白Env 是激发抗体反应的抗原，由于Env 全长有较大细胞毒性，本文采用 了截短的gp140 分子，删除了gp41 的胞内段，降低了gp140 蛋白的细胞毒性。同时保 留了gp41 的跨膜区，表达的蛋白可被正确地锚定在细胞表面，提高蛋白的免疫原性。 将gp140 分子克隆到复制缺陷型的腺病毒载体中，用Wester Blotting 方法检测到gp140 在293 细胞中的表达。 有效的抗 HIV-1 的疫苗应该能够同时激发针对多种亚型病毒株的细胞和体液免疫 反应。早期病毒蛋白激发的CTL 应答在控制病毒载量上更为有效，而且Tat 蛋白的重 要免疫抗原表位和功能区域在不同HIV-1 病毒株之间是高度保守的。Tat 蛋白的多种生 物学功能使得它成为较强的免疫原、共抗原和佐剂，激发T 细胞抗原表位的Th1 型反 应和CTL 反应，扩大体内T 细胞识别的抗原表位谱，提高T 细胞特异性免疫反应。本 文扩增了HIV-1ⅢB 的tat 基因，克隆到复制缺陷性的腺病毒中，构建了重组腺病毒 vAd-tat，并在293 细胞中表达了分子量大小为15kDa 的蛋白。早期蛋白和结构蛋白的联合免疫能够全面地控制病毒复制，在动物实验中一定程度 上保护了猴子。我们将已得到表达的gp140 和tat 基因进行融合表达。利用融合PCR 技 术，扩增gp140 和tat 的融合基因，构建携有HIV-1 gp140-tat 融合基因的重组腺病毒 vAd-gp140-tat。gp140-tat 在293 细胞中的融合表达还需要进一步验证。 下一步的工作是将构建好的重组腺病毒感染DC，检测外源基因在DC 中的表达水 平，对DC 表面分子表型的影响以及对DC 功能的影响。

猕猴MHC研究及在AIDS动物模型中的意义

主要组织相容性复合体(MHC)是与免疫应答和移植排斥直接相关的一组基因群.由于MHC高度的多态性,使其在脊椎动物的免疫遗传、进化、保护以及与疾病的相关性等方面的研究倍受关注.猕猴MHC尤其是MHC Ⅰ类基因的组成与人类有显著差异,一个单体型中存在多个Mamu-A和Mamu-B基因.在猕猴AIDS模型中,MHC对病毒的免疫逃逸以及对AIDS疫苗的研究均有十分重要的作用,某些MHC Ⅰ类和MHCⅡ类基因能够显著延缓猕猴AIDS疾病的进展,为在人体中理解MHCⅠ类等位基因与免疫保护和控制病毒复制的相关性提供了一个良好的模型.

人类AIDS 的研究替身———非人灵长类动物模型

　非人灵长类动物模型在艾滋病发病机理、传播途径、免疫反应以及疫苗开发药物治疗等方面的研究具有重要作 用。根据不同的免疫缺陷病毒感染不同的灵长类动物,可将这一模型分为不同的种类, 其中HIV/ 黑猩猩模型、SIV/ 猕猴模型和SHIV/ 猕猴模型是目前应用最为广泛的模型。这几种模型都各有其优缺点,本文将简单介绍这几种艾滋 病非人灵长类动物模型的研究概况。

树突状细胞在AIDS灵长类动物模型疾病进程中的作用

非人灵长类动物模型在艾滋病(AIDS)发病机制、传播途径、疫苗和药物等方面的研究中具有重要作用。树突状细胞(DC)作为最重要连接先天免疫与获得性免疫的抗原递呈细胞,在AIDS发病进程中扮演着重要的角色。研究非人灵长类AIDS动物模型中DC亚群数量、表型以及功能的变化,对揭示AIDS发病机制具有十分重要的意义。该文将重点总结近些年来DC亚群在AIDS动物模型发病机制中的作用研究进展,为以后的研究提供思路。

Synthesis of composite AIN powder mixed with sintering additives by the Lanxide method

Composite AlN powder, mixed with the sintering additive Y2O3, was synthesized by the direct nitridation of molten Al-Mg-Y alloys. The character of products was determined by means of electron microscopy, X-ray diffraction, granularmetric analysis and chemical composition analysis etc. The results show that the nitridation rate of the raw alloys is higher, and the nitridation products axe porous enough to be easily crushed. Composite AlN powder, obtained by the Lanxide method, has excellent characters such as high purity, especially low oxygen content, and narrow well-distributed grain size and so on.

AIDS猕猴模型在HIV疫苗研究中的应用

：对HIV 疫苗的研究一直是国际上艾滋病方面研究的热点和难点。动物模型则为疫苗研究必不可缺少的 重要工具，缺乏合适的动物模型很大程度上制约了AIDS疫苗的研究。目前在国际上SIV 或SHIV 感染的猕猴模 型为最常用的AIDS研究模型，受猕猴背景及病毒特性等多种因素的影响，使得以上两种模型在HIV疫苗研究中 仍存在一定的局限性。为了更好地发挥猕猴模型在HIV疫苗研究中的巨大潜力，开发理想的AIDS猕猴模型已成 为目前HIV疫苗研究的首要任务。本文简要介绍了AIDS疫苗的研发策略、研发概况以及SIV／SHIV猕猴模型在 HIV疫苗中的应用，并对其中存在的问题及其应用前景进行了探讨。

Establishment of AIDS Animal Model with SIVmac239 Infected Chinese Rhesus Monkey

In the present research, two Chinese rhesus monkeys were inoculated intravenously with 5000 TCID50 of SIVmac239. The changes in the numbers of CD4+ T lymphocyte in peripheral blood, plasma viral loads, proviral DNA and humoral antibodies against virus were periodically monitored during 121 days. At the early stage of infection, proviral DNA had been detected in PBMCs, and infectious SIVmac239 virus had been isolated from PBMCs. At the same period, the numbers of CD4+ T lymphocytes were significantly decreased, and maintained at low level during the 121-day period of infection. Plasma viral loads reached the peak at week 2 post-inoculation and kept at a steady state subsequently. Moreover, antibodies against viral proteins were detected from plasma. All the results showed that the two Chinese rhesus monkeys had been infected with SIVmac239 successfully. This animal model can be applied for further AIDS researches.