自然免耕下的稻田生态系统

自然免耕是一种新型的稻田耕作法,通过人为改变地表微地形,建立了一个适合水旱作物复种轮作,鱼、萍、鸭周年共生的稻田生态系统．自然免耕促进了土壤内、外环境的物质、能量和信息交换,水、热、气、肥谐调．并通过环境网络效应,强化了环境与生物区系间的缓冲－调节力．提高了土壤自调能力和土壤有序度．     

发酵活性豆渣饲料的研究

活性豆渣饲料是新鲜豆渣经微生物发酵而得到的。本文介绍了发酵菌株的筛选过程,并对发酵的最适条件进行了研究。分析结果表明,这种饲料含有蛋白酶等多种酶类,蛋白质、氨基酸的含量均比未发酵的豆渣有所增加,而且克服了豆渣含水量大、易腐败的缺点,有利于畜禽更充分地消化吸收。经动物喂养实验证明．活性豆渣饲料可代替５０％以上的鱼粉,是一种非常理想的蛋白饲料。     

Identification and Characterization of Protein Kinase FA/ Glycogen Synthase Kinase 3 in Clathrin-Coated Brain Vesicles

Abstract: Mg-ATP-dependent protein phosphatase activating factor [kinase F_A/glycogen synthase kinase 3 (GSK-3)] has been identified in highly purified clathrin-coated vesicles (CCVs) isolated from pig brain. Kinase F_A was found to exist in an inactive state but can be activated by 1% Triton X-100 or [ M /Tris-HC] extraction in brain CCVs. Activation of kinase F_A in CCVs is due to disassociation of the kinase from CCVs as demonstrated on sucrose density-gradient ultracentrifugation and Sepharose CL-4B gel filtration. Using purified brain CCVs as substrates, kinase F_A enhanced the endogenous phosphorylation of assembly protein complexes in the molecular weight range of 100,000-130,000 severalfold, as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by autoradiography. Comparisons with well-defined brain CCV-associated endogenous protein kinases such as pp50 kinase/AP50 and casein kinase 2 provide evidence that kinase F_A/GSK-3 represents a third potent and unique CCV-associated protein kinase distinctly different from the previously described CCV protein kinases, suggesting the possible involvement of kinase FA in the regulation of CCV functions in the brain. The results also support the notion that protein kinase F_A is involved in cell surface signal transduction in the CNS.     

(蜓)类旋壁超微构造的研究——以麦(蜓)型旋壁为例

光学显微镜下的观察表明(蜒)类的旋壁属于钙质微粒壳类型,对它们的电镜观察揭示了组成旋壁的晶粒的大小、形态和排列方式.对具有致密层和蜂巢层型两层式旋壁的Triticites的电镜研究表明:其致密层由近等轴晶无定向排列而成;蜂巢层由短柱状晶定向排列组成板状复合体,进而组合成管状孔,镶嵌在不定向排列的近等轴品基质中构成.Pseudofusulina的致密层也由近等轴晶不定向排列构成,蜂巢层由粗柱晶定向排列组成纤状复合体,进而形成管状孔,镶嵌在近等轴晶基质中.     

The effect of hydration on the dynamics of trimethoprim bound to dihydrofolate reductase. A deuterium NMR study.

To determine the effect of hydration on the dynamics of a protein complex, we used deuterium nuclear magnetic resonance (NMR) techniques to examine a trimethoprim (TMP)/E. coli dihydrofolate reductase (DHFR) complex in its lyophilized, partially hydrated, polycrystalline, and ammonium sulfate-precipitated states. The results indicate that TMP is rigid in the lyophilized powder state. The dynamic behavior could be restored by partial rehydration. At 30 wt% hydration the deuterium spectrum of the partially hydrated sample was indistinguishable from that of the polycrystalline and ammonium sulfate-precipitated samples, suggesting that the structure of the protein/TMP complex is similar in the three physical states. Furthermore, we found that the para- and meta-methoxyl groups have very different dynamical behavior.     

东方蝾螈繁殖生态的研究

本文报道东方蝾螈(Cynops orientalis)的繁殖生态,内容有精巢分叶、精子形态、怀卵量、性征、性比、求偶、交配、纳精、产卵及孵化等,并对产卵场中性比的周年变化、精包形态、精子存活力及与蓝尾蝾螈的种间差异进行了观察和讨论。     

Genetic transfer and expression of reconstructed yeast artificial chromosomes containing normal and translocated BCL2 proto-oncogenes.

The goal of this study was to determine whether it will be feasible to study the expression of a large, human gene, such as the BCL2 proto-oncogene, by DNA transfection. The BCL2 proto-oncogene is 230 kb in size and is deregulated in tumor cells by translocation into the immunoglobulin heavy-chain locus. Yeast artificial chromosomes (YACs) containing the human BCL2 gene were altered by homologous recombination in Saccharomyces cerevisiae to yield replicas of the normal and translocated alleles. Constructions containing either allele and ranging in size from 360 to 800 kb were integrated stably into a mouse tumor line. Fifty-eight percent of the clones contained a copy of the entire YAC insert. Over 50% of these clones expressed appropriate levels of human BCL2 RNA and protein. These studies suggested that the expression of large human genes and their pathologic rearrangements can be studied by transfection techniques employing YACs propagated in S. cerevisiae.     

Structural and dynamic studies of a non-self-complementary dodecamer DNA duplex.

A non-self-complementary dodecamer duplex d(CCTAAATTTGCC).d(GGCAAATTTAGG) has been investigated in solution by high resolution 1H NMR. Almost complete resonance assignment of both non-exchangeable and exchangeable protons, has been achieved. The duplex is essentially B-type, with distortions apparent at the AT and TA steps. These distortions and their affects on dynamics have been probed by the measurement of base-pair lifetimes, and observation of water of hydration. Base-pair opening rates were derived from measurements of T1's and effects on linewidths of the T and G imino protons on addition of an exchange catalyst. Our results are generally in line with observations reported for other systems, but we see only a slight drop in the A.T base-pair lifetime on moving out from the central region. This observation is reinforced by the detection of DNA-water nOe's for residues distributed throughout the dodecamer sequence.     

激光辐照真菌的酯酶,淀粉酶同工酶研究

本文报导了用He—Ne激光辐照真菌米曲酶的酯酶同工酶和淀粉同工酶的分析研究结果,实验表明激光对米曲霉同工酶有一定的影响。     

在中国壮族家系中发现的一例-α~T/-α~Q复合β~0β~0珠蛋白基因型

本文报道在我国广西隆林壮族中发现一个罕見的HbQ复合α,β地中海贫血家系。先证者女,18岁,贫血面容,肝脾肿大。化学结构分析确证本Hb变异体为HbQ Thailand[α74(EF3)Asp→His]。血红蛋白组成以及α和β珠蛋白基因分析结果表明,先证者的珠蛋白基因型为-α~Q/-α~T复合β°/β°(IVSI-1G→T/Codon17A→T);先证者父的基因型为-‘α~Q/-复合β~O/β~A(IVSI-1G→T/β~A);先证母的基因型为-α~T/αα复合β~O/β~A(Codon17A→T/β~A)。