微藻光合放氢的生理生化调控及生物技术研究

氢能将是主宰未来世界的主要能源之一，氢能的研究开发已经成为世界各国能源研究的重要方向。微藻光合制氢，因其无污染、可再生，成为生物制氢领域最有应用前景的研究方向之一。 本论文选取模式植物莱茵衣藻、经济藻种钝顶螺旋藻作为实验材料，对微藻光合放氢的生理生化过程调控及相关生物技术进行综合研究。获得的主要成果如下： （1）建立起微藻两步法放氢的技术平台和批次培养的回馈监控模式;同时，运用离子色谱追踪整个放氢过程中的离子变化，我们的实验结果证明对于衣藻两步法放氢而言，乙酸的存在是必要条件之一。这个结果与文献报道不尽相同，值得进一步深入地研究。 （2）筛选出一株联合固氮菌，摸索出藻菌共培养的培养基合适配置和活性控制条件;在两步法放氢的基础上，充分利用藻菌之间的优势互补，设计构建藻菌共培养放氢体系，与两步法放氢比较，该体系能提前12小时进入放氢状态，提高单位叶绿素放氢效率1倍左右，延长体系稳定时间近20小时。 （3）利用固定化技术获得高产氢效率，去固定化后持续产氢是我们设计出微藻连续放氢的一个特点。同时，摸索出衣藻放氢过程中的间歇进料进流程序，使连续放氢时间可达3周左右。 （4）实验证明两步法放氢技术，并不适用于螺旋藻;同时，在摸索建立螺旋藻的藻菌共培养放氢体系过程中，发现非致病性肺炎克雷伯氏杆菌培养液可以破碎螺旋藻细胞，这种全新的提取藻蓝蛋白的方法，具有节约成本，便于操作，温和均匀的独特优势。 （5）在连续放氢体系中加入适量蔗糖做底物和引物，剩余存活的菌可以继续利用提取藻蓝蛋白后剩余螺旋藻藻渣和放氢后死亡的衣藻进行发酵放氢，可获得更高产率的氢气，之后继续利用光合细菌进一步放氢，形成连续放氢网络，这一步还在探索之中。 作为一项应用基础研究，从三角瓶里的实验到工厂化生产还有很长的路，希望本实验的工作能为以后同类研究提供一些有用的信息和启发。

恒河猴TRIM5α的组织分布及不同刺激促进PBMC中TRIM5α转录水平的上调

TRIM5α(tripartite motif protein 5-alpha)蛋白是恒河猴体内一种非常重要的限制因子,能抑制人免疫缺陷病毒(HIV-1,human immunodeficiency virus type 1)、马感染性贫血病毒(EIAV, equine infectious anemia virus)和猫免疫缺陷病毒(FIV, feline immunodeficiencyvirus)等逆转录病毒的复制.恒河猴TRIM5α的组织分布以及在受到外界刺激时TRIM5α mRNA表达量的变化研究还未见报道.本研究从中国恒河猴的各组织中提取总RNA,以β-actin基因作为内参照,通过半定量RT-PCR检测各组织中TRIMSα mRNA的表达.选择HIV-GFP-VSVG假病毒感染外周血单核细胞(peripheral blood mononuclear cell,PBMC),非特异性刺激剂--佛波脂(Phorbol myfismte acetate,PMA)+离子霉素(ionomycin,Ion)及CD28抗体+CD49d抗体分别共刺激恒河猴PBMC,研究不同刺激对恒河猴TRIM5α mRNA表达水平的影响.结果表明:TRIM5α mRNA表达于所研究的恒河猴21种组织中,免疫系统和泌尿生殖系统组织中表达量最高,而神经系统组织,如大脑、脊髓中表达较少,其他组织中未见明显的表达差异;HIV-GFP-VSVG感染和用PMA+Ion、CD28抗体+CD49d抗体分别共刺激PBMC能促进PBMC中TRIM5α mRNA的转录水平的上调.

法落海的化学成分及抗HIV活性

下载PDF阅读器利用多种柱层析方法,从法落海(Angelica apaensis)95%乙醇提取物中分离得到8个化合物.经IR、MS、NMR等波谱数据鉴定为氧化前胡素(oxypeucedanin,1)、氧化前胡素水合物(oxypeucedanin hydrate,2)、异欧芹属乙素(isoimperatorin,3)、白当归脑(byakangelicin,4)、白当归素(byakangelicol,5)、3'-O-acetylhamaudol (6)、(+)-9(Z),17-octadecadiene-12,14-diyne-1,11,16-triol(7)和9,17-octadecadiene-12,14-diyne-1,11,16-triol,1-acetate(8),其中,化合物6-8是首次从该植物中分离得到.我们对所有得到的8个化合物进行抗HIV活性分析,化合物1具有明显的抗HIV活性,其抑制合胞体形成的半数有效浓度(EC50)为1.6 ms/L,治疗指数(TI)为17.59.

Anti-HIV-1 activities of extracts from the medicinal plant Rhus chinensis

Rhus chinensis, a species used in folk medicine by Chinese native people, the anti-HIV-1 activities of the petroleum ether, ethyl acetate, butanol and aqueous extract of Rhus chinensis, named as RC-1, RC-2, RC-3 and RC-4, respectively, was evaluated. The

Lead exposure through gestation-only caused long-term learning/memory deficits in young adult offspring

Numerous observations in clinical and preclinical studies indicate that the developing brain is particular sensitive to lead (Pb)'s pernicious effects. However, the effect of gestation-only Pb exposure on cognitive functions at maturation has not been studied. We investigated the potential effects of three levels of Pb exposure (low, middle, and high Pb: 0.03%, 0.09%, and 0.27% of lead acetate-containing diets) at the gestational period on the spatial memory of young adult offspring by Morris water maze spatial learning and fixed location/visible platform tasks. Our results revealed that three levels of Pb exposure significantly impaired memory retrieval in male offspring, but only female offspring at low levels of Pb exposure showed impairment of memory retrieval. These impairments were not due to the gross disturbances in motor performance and in vision because these animals performed the fixed location/visible platform task as well as controls, indicating that the specific aspects of spatial learning/memory were impaired. These results suggest that exposure to Pb during the gestational period is sufficient to cause long-term learning/memory deficits in young adult offspring. (C) 2003 Elsevier Inc. All rights reserved.

Pneumonia in cats caused by Pneumocystis carinii purified from mouse lungs

Fourteen mice trapped in or near houses were infected with Pneumocystis carinii and the establishment of pneumonia was helped by injecting with cortisone acetate for 6 weeks. Then 16 cats were infected with P. carinii by injection of lung homogenate from the mice which contained from 1.3 X 10(5) to 2.6 X 10(5) P. carinii cysts. The infection resulted in severe cough and tachypnea in Cats 1-8 injected with cortisone acetate, and a subclinical infection in Cats 9-16. In Cats 1-8, the main pathological finding was typical P. carinii pneumonia, but there only was slight swelling of the lungs in Cats 9-16.

Enhanced protection against oxidative stress in an astaxanthin-overproduction Haematococcus mutant (Chlorophyceae)

Many unicellular green algae can become yellow or red in various natural habitats due to mass accumulation of a secondary carotenoid, such as lutein, or astaxanthin. The accumulation of secondary carotenoids is generally thought to be a survival strategy of the algae under photo-oxidative stress or other adverse environmental conditions. The physiological role of the carotenoids in stress response is less well understood at the subcellular or molecular level. In this study, a stable astaxanthin overproduction mutant (MT 2877) was isolated by chemical mutagenesis of a wild type (WT) of the green microalga Haematococcus pluvialis Flotow NIES-144. MT 2877 was identical to the WT with respect to morphology, pigment composition, and growth kinetics during the early vegetative stage of the life cycle. However, it had the ability to synthesize and accumulate about twice the astaxanthin content of the WT under high light, or under high light in the presence of excess amounts of ferrous sulphate and sodium acetate. Under stress, the mutant exhibited higher photosynthetic activities than the WT, based on considerably higher chlorophyll fluorescence induction, chlorophyll autofluorescence intensities, and oxygen evolution rates. Cell mortality caused by stress was reduced by half in the mutant culture compared with the WT. Enhanced protection of the mutant against stress is attributed to its accelerated carotenogenesis and accumulation of astaxanthin. Our results suggest that MT 2877, or other astaxanthin overproduction Haematococcus mutants, may offer dual benefits, as compared with the wild type, by increasing cellular astaxanthin content while reducing cell mortality during stress-induced carotenogenesis.

Optimization of growth and fatty acid composition of a unicellular marine picoplankton, Nannochloropsis sp., with enriched carbon sources

A unicellular marine picoplankton, Nannochloropsis sp., was grown under CO2-enriched photoautotrophic or/and acetate-added mixotrophic conditions. Photoautotrophic conditions with enriched CO2 of 2800 mul CO2 l(-1) and aeration gave the highest biomass yield (634 mg dry wt l(-1)), the highest total lipid content (9% of dry wt), total fatty acids (64 mg g(-1) dry wt), polyunsaturated fatty acids (35% total fatty acids) and eicosapentaenoic acid (EPA, 20:5omega3) (16 mg g(-1) dry wt or 25% of total fatty acids). Mixotrophic cultures gave a greater protein content but less carbohydrates. Adding sodium acetate (2 mM) decreased the amounts of the total fatty acids and EPA. Elevation of CO2 in photoautotrophic culture thus enhances growth and raises the production of EPA in Nannochloropsis sp.

Endocrine effects of sublethal exposure to persistent organic pollutants (POPS) on silver carp (Hypophthalmichthys molitrix)

Silver carp (Hypophthalmichthys molitrix) samples were collected from five selected sites that represent diverse levels of downgraded persistent organic pollutants (POPs) contamination in Ya-Er Lake in October 1999. Hepatic ethoxyresorufin-O-deethylase (EROD) and UDP glucuronosyltransferase (UDPGT) activities, hepatosomatic index (HSI), hepatic retinoids, serum thyroid hormones were measured. It was found that hepatic retinol and serum free 3,5,3'- tetraiodothyronine (FT3) significantly increased (P < 0.01) when both hepatic EROD and UDPGT activities significantly declined (P < 0.01) from pond 1 to 5 with decrease in the degree of pollution. This significant negative correlation (P < 0.01) suggests that the persistent organochlorinated contaminants could induce hepatic EROD and UDPGT activities, alter retinoid and thyroid hormone homeostasis, and finally lead to the reduction of retinol and FT3, the two biologically active forms of retinoids and thyroid hormone in silver carp of Ya-Er Lake. (C) 2002 Elsevier Science Ltd. All rights reserved.

Photoluminescence of ZnO : Tb nanoparticles

Terbium-doped zinc oxide nanoparticles have been prepared by hydrolyzing zinc acetate and terbium acetate. Nanoparticle-matrix-facilitated photoluminescence which is related to Tb3+ ions has been observed for ZnO:Tb nanoparticles. The dependence of emission intensity on doping concentration of Tb3+ ions has been investigated. An energy transfer from excited states of ZnO hosts to dopants is disclosed by the fact that the emission intensity of Tb3+ centers increases with increasing Tb content at the expense of emission from defect states in ZnO matrix.

Surface states induced photoluminescence from Mn2+ doped CdS nanoparticles

Manganese doped CdS nanoparticles were synthesized in basic aqueous solution by using mercapto acetate as capping reagents. The nanoparticles were characterized by HRTEM, EPR, photoluminescence and optical absorption measurements. Out of our expectation, doping of Mn2+ ions altered the recombination paths in CdS nanoparticles markedly. The surface stares facilitated PL from Mn2+ doped CdS nanoparticles is reported. A complete suppression of the emission from surface states at room temperature when doping with Mn2+ ions has been observed for the first time. (C) 2000 Elsevier Science Ltd. All rights reserved.

Correlated structural and optical investigation of terbium-doped zinc oxide nanocrystals

Tb3+-doped zinc oxide nanocrystals with a hexagonal wurzite structure were successfully prepared by reaction between Zn-O-Tb precursors and LiOH in ethanol. Good incorporation of Tb3+ in ZnO nanocrystals is proved by XRD, FTIR, PL and PLE measurements. The presence of acetate complexes to zinc atoms on particle surfaces is disclosed by FTIR results. Emission from both Tb3+ ions and surface states in ZnO matrix, as well as their correlation were observed. The luminescence mechanism is discussed. (C) 2000 Elsevier Science B.V. All rights reserved.

MoNi/gamma-Al2O3 Catalyst: Preparation and Catalytic Activity for Acetic Acid Hydrotreating

MoNi/gamma-Al2O3 catalysts were prepared by the impregnation method. The catalyst samples were characterized by XRD and TPR. The effects of Mo promoter content and the catalyst reducing temperature Oil hydrotreatment activity of the catalyst were studied under 200 degrees C and 3 MPa hydrogen pressure using acetic acid as the model compound. The XRD results indicate that the addition of Mo promoter is beneficial to the uniformity of nickel species on the catalyst and decreases the Interaction between nickel species and the support Which results in the decrease the of NiAl2O4 spinel formation. The addition of Mo promoter also decreases the reducing temperature of the catalyst. After the catalyst of 0.06 MoNi/gamma-Al2O3 being reduced Under the atmosphere of H-2/N-2(5/95, V/V), nickel oxide was reduced to Ni-0. The reaction was promoted obviously upon the addition of the MoNi/gamma-Al2O3 catalyst reduced at 600 degrees C. The Mo-modified Ni/gamma-Al2O3 catalyst reduced at 600 degrees C displayed the highest activity during the reaction, the conversion of acetic acid reached the highest point of 33.2%. The products included ethyl acetate and water.

Fluorescence pH probe based on microstructured polymer optical fiber

A kind of optical pH sensor was demonstrated that is based on a pH-sensitive fluorescence dye-doped (eosin) cellulose acetate (CA) thin-film modified microstructured polymer optical fiber (MPOF). It was obtained by directly inhaling an eosin-CA-acetic acid mixed solution into array holes in a MPOF and then removing the solvent (acetic acid). The sensing film showed different fluorescence intensities to different pH solutions in a pH range of 2.5-4.5. Furthermore, the pH response range could be tailored through doping a surfactant, hexadecyl trimethyl ammonium bromide (CTAB), in the sensing film. (c) 2007 Optical Society of America.

恒河猴TRIM5α 的组织分布及TRIMCyp 限制HIV-1 病毒颗粒产生的初步研究

三重基序蛋白TRIM5α(Tripartite motif protein 5 alpha)是哺乳动物细胞中一种重要的限制因子，广泛分布于各种哺乳动物细胞中。人类TRIM5α mRNA 广泛表达于人类各个组织中，并且I 型干扰素IFN-α/β/γ 均能与TRIM5α 基因启动子的ISRE 元件结合，上调TRIM5α mRNA 的表达。恒河猴(Macaca mulatta)TRIM5α 是恒河猴体内重要的限制因子。目前对恒河猴尤其是中国恒河猴TRIM5α 的组织分布以及在受到外界刺激时TRIM5α mRNA 表达量的变化研究还未见报道。本论文通过从中国恒河猴各组织中提取总RNA，以β-actin 基因作为内参照，通过逆转录PCR 检测各组织中TRIM5α mRNA 的表达。我们选择用HIV-GFP-VSVG 感染、用佛波脂(Phorbol myfismte acetate, PMA)+离子霉素(Ionomycin, Ion)，CD28 抗体+CD49d 抗体分别共刺激恒河猴PBMC，研究不同刺激对中国恒河猴TRIM5α mRNA 表达量的影响。研究发现：TRIM5α mRNA 广泛表达于恒河猴各组织中，在免疫系统和泌尿生殖系统各组织，如腹淋巴结、睾丸和附睾中表达量最高，而在神经系统各组织如大脑、脊髓中表达量比较少，在其他各组织中未见明显的表达差异。此外HIV-GFP-VSVG 感染、PMA+ Ion 与CD28 抗体+CD49d 抗体分别共刺激PBMC 均能促进PBMC TRIM5α mRNA 表达量的上调。 TRIM5α 作为恒河猴体内的最主要的限制HIV-1 感染的限制因子，除了可能通过促进HIV-1 的脱壳和阻止整合前复合物PIC(pre-integration complex)入核，恒河猴TRIM5α 还能限制HIV-1 病毒颗粒的产生。在这个过程中B30.2 结构域是非必需的，而B-box2 和Coiled-Coil 结构域起着决定性的作用。因为鹰猴(Aotes trivirgatus)TRIMCyp(omTRIMCyp) 蛋白和北平顶猴(Macaca leouina) TRIMCyp(npmTRIMCyp）蛋白的B-box2 和Coiled-Coil 结构域与恒河猴TRIM5α 的B-box2 和Coiled-Coil 具有很高的同源性，我们希望了解鹰猴TRIMCyp 蛋白和北平顶猴TRIMCyp 蛋白对HIV-1 病毒颗粒的产生是否有限制作用。本论文主要通过将质粒pNL4.3 分别与质粒pLPCX 、pLPCX-npmTRIMCyp-HA 、 pLPCX-omTRIMCyp-HA和pLPCX-rhTRIM5α-HA共转染293T细胞，通过western blot 检测细胞内Gag 蛋白和TRIM5 蛋白的表达情况，研究omTRIMCyp 蛋白和 npmTRIMCyp 蛋白对HIV-1 病毒颗粒产生的限制作用。结果表明：北平顶猴 TRIMCyp 蛋白、鹰猴TRIMCyp 蛋白都能不同程度的促进HIV-1 病毒Gag 蛋白的降解。