龙眼树形对生长结果及机理影响初探

为了解决龙眼园的郁闭问题,提高龙眼的产量和品质,该文以桂香龙眼品种为材料,研究了扁开心形、开心形、自然圆头形三种不同树体结构对树体光照强度、叶片、根系、果实的影响。结果表明:扁开心形显著改善了树冠和果园通风透光环境,提高了叶绿素含量,增大了叶面积,提高了PSⅡ系统活性和开放程度,调节了光合机构的自我保护机制,改善了荧光参数,从而提高了果实品质;扁开心形、开心形、对照的单株产量分别是19.90、17.00、15.60 kg,单果重分别是10.24、10.07、7.64 g;扁开心形和开心形可食率比对照分别提高了4.20%、4.40%,可溶性固形物含量分别提高了12.16%、12.55%;扁开心形比开心形以及对照的表层根有所上浮,促进了果树的生殖生长,显著扩大了根系的分布深度,扩大了根系对营养物质以及水分的吸收。扁开心形是一种高光效的树形,应在生产上加以推广。     

我国蓝藻水华的发生机理、危害及防控利用研究进展

近些年蓝藻水华的大规模爆发不仅危害了水产养殖业,而且严重影响了人类日常生活、供水、旅游业等。主要介绍了蓝藻水华爆发的内在因素（假空泡、类胡萝卜素、厚壁孢子、细胞壁等）及外在因素（营养物质、温度、微量元素、滤食性鱼类等）。阐述了蓝藻水华对生产、生态和生活造成的危害,归纳总结了蓝藻水华防控的化学、物理、生物等方法。最后描述了蓝藻水华的有效利用并提出其研究中存在的问题。     

陕西省植物引种驯化的回顾与展望

回顾了陕西植物引种驯化的成就、经验,特别是对区域性的引进种类、成功事例进行了较详尽的叙述,并在此基础上讨论了引种驯化的理论、方法与技术措施、路线,展望了陕西植物引种驯化的趋向,提出了若干建议。     

甘肃省东乡、保安、裕固三个民族的ABO血型分布

本文调查了东乡、保安、裕固三个民族1129人的ABO血型,得出了东乡、保安、裕固民族ABO血型的分布,并与其他学者的报告作了比较,探讨了这三个民族的起源。     

抚育间伐对人工林土壤肥力的影响

研究了杉木、马尾松、建柏、柳杉和木荷人工林的抚育间伐对林分土壤肥力的影响.结果表明,杉木、马尾松、建柏、柳杉、木荷间伐后降低了林分的郁闭度.改变了林内的生境条件,促进了林下乡土植被的生长和繁衍,林下植被覆盖度、植被生物量和物种丰富度有了较大幅度的增加,间伐的强度越大.增加的幅度也越大.与不间伐林分相比,各间伐林分两年后土壤微生物数量增加、酶活性增强、土壤容重降低、总孔隙度和速效养分提高,土壤肥力得到了改善和提高.间伐后林分土壤肥力得到提高的实质在于:间伐后林下植被生物多样性的提高诱发了土壤微生物多样性和数量的提高,并由此而增强了土壤的生物活性,加速了土壤养分的循环.     

猴头菌属药用真菌活性次级代谢产物研究概况

对猴头菌属药用真菌的次级代谢产物化学、生物活性研究进行了综述。目前已经从猴头菌属真菌中发现了83个不同类型的活性次级代谢产物,主要包含二萜类、酚类、脂肪酸类、甾体、生物碱类化合物;这些化学成分显示了抗肿瘤、抗菌、抗糖尿病、促进神经生长因子合成等多种活性。文中讨论了目前研究的主要问题并对其前景进行了展望。     

改良型抗菌肽的研究进展

长期滥用抗生素导致了耐药菌株“超级细菌”的出现,增加了动物、人类健康和环境污染风险．寻找抗生素替代品正成为全球研究热点,抗菌肽因其高效抗菌效果和不同于抗生素的独特作用机制引起了各国研究者的关注,并进行了相关研究．然而抗菌肽的安全性、稳定性、生产成本等问题限制了其生产与应用．为了克服这些不利因素,研究者们对抗菌肽进行了多种方式的改造,产生了模拟型、同源型、杂合型、轭合型、稳定型和固位型等改良型抗菌肽,并有望在畜牧业、食品业、医药业等领域得到广泛的应用．本文主要综述了这些改良型抗菌肽近年来的研究进展．     

中科院水生所开发名优水产健康高效养殖技术

近日,由中国科学院水生生物研究所、华中农业大学、长江大学等单位承担的湖北省“十五”科技攻关计划重大项目“名优水产品健康高效养殖技术研究及产业化开发”通过了湖北省科技厅组织的专家组验收。科研人员系统地研究了黄鳝、长吻能、黄颡鱼、鳜鱼和青虾的繁殖、营养、养殖等关键技术;合理评估了鳜鱼、河蟹和青虾的养殖容量和生态效应,提出了鳜鱼的湖泊放养措施和管理模式;完成了中华鳖的快速培育技术和大水面的无公害养殖生产技术。建立了健康、     

景观可视化及其应用

介绍了景观可视化的概念,回顾了景观可视化的发展历程,然后介绍了景观要素,包括地形、植被、水、人工构件(建筑物、基础设施等)、动物(包括人)、大气和光的可视化表达方法,阐述了景观可视化在景观规划、景观变化、气候变化、城市景观、景观视觉影响评价和森林管理等方面的应用,最后提出了景观可视化的未来发展趋势.     

肾阴虚证的现代研究进展

肾阴虚证是中医学的基本证型之一.对中医证的研究,基本方法是运用现代科技手段,通过动物实验与临床研究,探讨疾病发生后"证"与人体生理变化、病理、生化等客观指标的关系,尝试揭示证的实质.几十年来,不少学者从细胞、分子等水平上对肾阴虚证本质做了深入地研究,并已取得了一定的成果,某些方面已形成了共识.这不仅丰富和发展了传统的中医肾阴虚理论,而且为肾阴虚证的临床诊断、治疗、预后判断提供了更客观的、更全面的指导作用.本文从神经内分泌、免疫、微量元素、脂代谢、自由基、细胞因子与介质、基因等方面对肾阴虚证病理生理的客观化研究进展进行了详细地阐述.     

环境变异对青稞热稳定蛋白质含量及蛋白质Z的影响

热稳定蛋白是衡量麦芽品质的重要指标,为探明青稞籽粒和麦芽热稳定蛋白的含量、蛋白质Z的组成特征以及影响条件。本研究以3份青稞和1份对照大麦品种Gairdner为试验材料,对青稞籽粒及其麦芽的热稳定蛋白进行分析与鉴定,研究了不同生态环境下青稞热稳定蛋白质含量和蛋白质Z的组成特征,同时筛选出了优异啤用品质青稞品种(品系)。结果表明,青稞发芽温度为20℃,发芽时间为72 h,培养溶液PH为5时,发芽及焙焦条件下最有利于青稞热稳定蛋白总含量及蛋白质Z的累积。利用该发芽条件筛选种植于西宁、湟源和海晏的青稞资源,发现种植于西宁的青稞种子和发芽后热稳定蛋白质总含量最低,但是焙焦后热稳定蛋白质和蛋白质Z含量最高;同时从150份青稞资源中筛选出热稳定蛋白质含量及蛋白质Z条带清晰、含量高的优异资源15份。本研究结果为酿造青稞品种选育、啤用青稞和麦芽质量评价指标提供理论依据。     

The Effect of Manganese on the Reconstitution of Partial Metallocluster-deficient Nitrogenase Molybdenum-Iron Protein

By treating the reduced MoFe protein of nitrogenase from Azotobacter vinelandii with O-phenanthroline (O-phen) and O2, inactive MoFe protein which was partialy deficient in both P-cluster and FeMoco could be obtained. After incubating the inactive protein with a reconstituent solution containing KMnO4, ferric homocitrate, Na2S and dithiothreitol, a reconstituted protein could be obtained. The absorption spectrum and C2H2, H+ and N2 reduction activity of the reconstituted protein could be well restored to the state of the reduced MoFe protein. However, the α-helix and CD spectrum at 380—550 nm and at 620—670 nm of the reconstituted protein were somewhat different from those of the reduced MoFe protein. The results showed that: (1) the reconstituted protein was composed of the assembled protein which might be a MnFe protein due to the reconstitution of the metalloclusterdeficient MoFe protein with Mn-containing solution and MoFe protein in which metalloclusters were still intact after the treatment with O-phen and O2; (2) It might be possible that the MnFe protein and MoFe protein were similar in the ability of nitrogen fixation, but were somewhat different in the structure from each other.     

微管解聚剂和光合作用抑制型除草剂诱导的黑麦和玉米中蛋白质组分变化的比较研究

研究了黑麦、玉米在经甲基胺草膦和Atrazine两种除草剂处理后叶绿素含量、叶绿体和根尖分生组织内的蛋白质组份变化,实验结果表明,0.1 mg·L^-1的Atrazine可使黑麦中的叶绿素含量下降（分别从对照的1.72±0.034 mg·g^-1 FW下降到1.62±0.05 mg·g^-1 FW、1.25±0.015 mg·g^-1 FW）。2种除草剂均可使黑麦、玉米中的蛋白质组份产生改变,如当分别用0.1 mg·L^-1的Atrazine处理时,黑麦分生组织中,有4个蛋白质斑点,斑点7、斑点18~20被诱导产生,12个蛋白质斑点,斑点6、斑点8~17、斑点21消失。玉米分生组织中,有4个蛋白质斑点,斑点5、斑点14~16被诱导产生,4个蛋白质斑点,斑点17~20消失。黑麦叶绿体中,有两个蛋白质斑点被诱导产生,13个蛋白质斑点,斑点1~13消失,但Atrazine处理不引起玉米叶绿素含量和叶绿体蛋白质组份的变化。4 mg·L^-1 APM可引起黑麦和玉米分生组织蛋白质组份变化,在黑麦中,1个蛋白质斑点被诱导产生,4个蛋白质斑点,斑点2~5消失。玉米分生组织中,15个蛋白质斑点,斑点4~5、斑点7~16、斑点21~23被诱导产生,4个蛋白质斑点,斑点1~3、斑点6消失。APM均不能引起2种作物中叶绿素含量和叶绿体蛋白质组份的变化。     

基于序列特征网络的蛋白质结构类型研究

利用复杂网络的方法来探索序列特征因素对蛋白质结构的影响。由于蛋白质的序列对结构具有重要且复杂的影响,因此将蛋白质的结构以及序列特征之间的关系模拟成一个复杂系统,通过利用互相关系数、标准化互信息和传递熵等方法来建立以序列特征为节点的加权网络,进而利用网络中心性的方法来分析不同蛋白质结构类型对应加权网络的中心性分布的差异,探索不同结构类型蛋白质的序列特征差异。发现不同的蛋白质结构类型对应的序列特征网络既有共性又有差异,文章将针对每一种结构类型的网络中心性分布,以及不同结构类型之间的共性与差异进行详细地讨论。研究结果对蛋白质序列与结构之间关系的研究,特别是结构分类研究具有重要的意义。     

链球菌蛋白G的构建、重组表达及鉴定

化学合成链球茵蛋白G的C3D基因片段,通过分子生物学的方法对蛋白G（proteinG）的C3片段进行PCR扩增,拼接形成含有两个和三个重复C3片段的重组链球茵蛋白G,C3片段间以链接区D连接,即形成C3DC3和C3DC3DC3的形式,进而克隆到质粒pET21中,在大肠杆菌BL21（DE3）中表达。重组表达的蛋白经过DEAE—Sepharose和IgG—Sepharose纯化,得到纯化的重组蛋白。采用非竞争性酶免疫法对重组蛋白与不同来源IgG的结合常数进行测定,实验结果显示两种重组链球茵蛋白G均可有效地与小鼠、兔及山羊等多种不同来源抗体特异性结合。这些实验结果为下一步研究奠定了基础。     

Reactivation of Partially Metallocluster-deficient MoFe Protein by Chromium-Containing Reconstituent Solution

By treating the reduced MoFe protein from Azotobacter vinelandii with o-phenanthroIi e and O2, partially deficient in both FeMoco and P-cluster and inactive protein could be o rained. After incubating the treated protein with a reconstituent solution containing K2CrO4, ferric homocitrate, Na2S and dithiothreitol, a reactivated protein could be obtained. The absorption spectrum, circular dichroism spectrum, and the C2H2 and proton reduction activities of the reactivated protein were remarkably recovered. However, the spectra were somewhat different from those of the reduced MoFe protein. The results showed that some of the reactivated protein might be Cr-containing protein (CrFe protein) which were similar in function, but somewhat different in structure from MoFe protein.     

含铬重组液激活部分缺失金属原子簇的钼铁蛋白的研究

棕色固氮菌（Ａｚｏｔｏｂａｃｔｅｒ ｖｉｎｅｌａｎｄｉｉ）固氮酶钼铁蛋白经邻菲口罗啉和Ｏ２ 处理后,变为部分缺失ＦｅＭｏｃｏ 和Ｐ－ｃｌｕｓｔｅｒ的失活蛋白。与由Ｋ２ＣｒＯ４、高柠檬酸铁、Ｎａ２Ｓ和二硫苏糖醇组成的重组液保温后,处理蛋白对乙炔和质子还原的活性都得以显著恢复;然而,它的吸收光谱和圆二色谱虽有明显恢复,但仍与还原钼铁蛋白有所不同。这表明,激活蛋白中也许存在功能与钼铁蛋白相似,而结构则有所差异的含铬（ＣｒＦｅ）蛋白     

Energy and protein requirements of Belgian Blue double-muscled bulls

Energy and protein requirements were determined for Belgian Blue double-muscled (BB dm) bulls based on the results of two feeding trials and a trial with serial slaughtering. The results of the serial slaughter experiment allowed calculation of chemical composition and energy content of the empty body, as well as protein and energy deposition at various live weights between 350 and 650 kg. Protein requirements were calculated based on the protein requirements for maintenance, the protein mass accreted and the efficiency of protein accretion. Efficiency of protein deposition (g protein accretion/g protein intake for accretion) was derived from the feeding experiments based on marginal protein levels; it decreased from 0.53 to 0.44 with increasing live weight. Energy requirements were also derived from the same database. Net energy for maintenance was estimated, with these animals that received an optimum energy/protein ratio, by subtracting the net energy retained from the net energy intake. Requirements were then determined by summation of the energy requirements for maintenance and the energy requirements for accretion. Conclusively, energy and protein requirements were determined for BB dm bulls for live weights from 350 to 650 kg and for different growth rates. As such, surpluses of energy and protein that BB dm animals require compared to other beef breeds, were quantified.     

Purification of horse immunoglobulin isotypes based on differential elution properties of isotypes from protein A and protein G columns

Elution properties of horse immunoglobulin isotypes from protein A and protein G columns were examined. IgGa and IgGb isotypes were bound to protein A and protein G columns and were eluted by adjusting the pH of the elution buffer from 8.0 to 2.0. IgGc bound to protein G column but not to protein A column while IgG(T) bound to both columns. IgM and IgA apparently appeared not to bind to either column. New methods for purification of serum isotypes were developed using protein A and protein G columns as well as formerly established methods. Using these methods, it was possible to obtain purified isotypes for establishment of immunological assays for practical clinical use.     

Hydrolysis of lipid and protein reserves in loblolly pine seeds in relation to protein electrophoretic patterns following imbibition

The correlation between changes in seed protein electrophoretic patterns and the hydrolysis of lipid and protein reserves of loblolly pine ( Pinus taeda L.) seed was studied. Seeds were incubated at 30°C for up to 12 days following stratification, then megagametophytes and embryos were assayed for lipid and protein content after each day of imbibition. The megagametophyte of mature seed was found to contain 20% lipid and 12% storage protein on a fresh weight basis. The embryo contained 26% lipid and 15% protein. Both lipid and protein reserves were depleted constantly following imbibition. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of soluble and insoluble protein fractions showed a 60 kDa protein that was representative of crystalloid-like proteins. These crystalloid-like proteins comprised 85% of the insoluble protein storage reserves. A small number of insoluble storage proteins, including a 47 kDa protein, were distinct in that they were unaffected by 2-mercaptoethanol treatment. The soluble fractions from both tissues were labelled with [³⁵S]-methionine, and incorporation was visualized by two-dimensional electrophoresis. Proteins were found to belong to one of three categories, those synthesized constitutively (comprising the bulk of newly synthesized proteins), those synthesized during germination or those synthesized after radicle emergence. Accompanying seed reserve hydrolysis were developmental shifts in protein pattern and synthesis, suggesting the possibility that control of hydrolysis is at the level of enzyme accumulation.