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51.
This study describes variation of intron-3 of a-amylase gene from 156 breeds of adzuki beansusing SSCP(single-strand conformation polymorphism)analysis. Based on a-amylase gene structure and se-quence, A pair of PCR primers, F (CCTACATTCTAACACACCCT) and R (GCATATTGTGCCAGTACAAT)were designed to amplify intron-3 fragments of a-amylase gene. 14 variant types were detected, including 13,9, 10, 4 variant types in the wild, weed, locally cultivated and modern brought-up adzuki beans respectively,9, 8, 7 variant types of the wild adzuki beans from Japan, China and Korea respectively, and some other va-riant types in the local adzuki beans from China and Bhutan. 60 % of subjects of cultivated races were found tobe EE type in the experiment. In addition, sequence analysis of intron-3 of α-amylase gene from 8 varianttypes reveals the evolution process of various variant types in adzuki beans. 相似文献
52.
CTLA-4 control over Foxp3+ regulatory T cell function 总被引:1,自引:0,他引:1
Wing K Onishi Y Prieto-Martin P Yamaguchi T Miyara M Fehervari Z Nomura T Sakaguchi S 《Science (New York, N.Y.)》2008,322(5899):271-275
Naturally occurring Foxp3+CD4+ regulatory T cells (Tregs) are essential for maintaining immunological self-tolerance and immune homeostasis. Here, we show that a specific deficiency of cytotoxic T lymphocyte antigen 4 (CTLA-4) in Tregs results in spontaneous development of systemic lymphoproliferation, fatal T cell-mediated autoimmune disease, and hyperproduction of immunoglobulin E in mice, and it also produces potent tumor immunity. Treg-specific CTLA-4 deficiency impairs in vivo and in vitro suppressive function of Tregs-in particular, Treg-mediated down-regulation of CD80 and CD86 expression on dendritic cells. Thus, natural Tregs may critically require CTLA-4 to suppress immune responses by affecting the potency of antigen-presenting cells to activate other T cells. 相似文献
53.
Matsuo T Yamaguchi S Mitsui S Emi A Shimoda F Okamura H 《Science (New York, N.Y.)》2003,302(5643):255-259
Cell division in many mammalian tissues is associated with specific times of day, but just how the circadian clock controls this timing has not been clear. Here, we show in the regenerating liver (of mice) that the circadian clock controls the expression of cell cycle-related genes that in turn modulate the expression of active Cyclin B1-Cdc2 kinase, a key regulator of mitosis. Among these genes, expression of wee1 was directly regulated by the molecular components of the circadian clockwork. In contrast, the circadian clockwork oscillated independently of the cell cycle in single cells. Thus, the intracellular circadian clockwork can control the cell-division cycle directly and unidirectionally in proliferating cells. 相似文献
54.
A rational method for constructing highly oriented films of purple membrane (PM) has been established by using two kinds of bispecific antibodies with different antigen-binding sites, one binding to a specific side of bacteriorhodopsin and the other to a phospholipid hapten. A hapten monolayer deposited on a metal electrode was treated with a bispecific antibody solution and incubated with a PM suspension to produce a highly oriented PM film, as confirmed by electron microscopy in which an immunogold labeling technique was used. This antibody-mediated PM monolayer was then used in the construction of a light-sensing photoelectric device. A comparison of the two incorporated PM monolayers showed that highly efficient photocurrents were produced by the PM monolayer whose unidirectionally oriented cytoplasmic surface faces the electrode. 相似文献
55.
Ozyuzer L Koshelev AE Kurter C Gopalsami N Li Q Tachiki M Kadowaki K Yamamoto T Minami H Yamaguchi H Tachiki T Gray KE Kwok WK Welp U 《Science (New York, N.Y.)》2007,318(5854):1291-1293
Compact solid-state sources of terahertz (THz) radiation are being sought for sensing, imaging, and spectroscopy applications across the physical and biological sciences. We demonstrate that coherent continuous-wave THz radiation of sizable power can be extracted from intrinsic Josephson junctions in the layered high-temperature superconductor Bi2Sr2CaCu2O8. In analogy to a laser cavity, the excitation of an electromagnetic cavity resonance inside the sample generates a macroscopic coherent state in which a large number of junctions are synchronized to oscillate in phase. The emission power is found to increase as the square of the number of junctions reaching values of 0.5 microwatt at frequencies up to 0.85 THz, and persists up to approximately 50 kelvin. These results should stimulate the development of superconducting compact sources of THz radiation. 相似文献
56.
山口喜久二 《云南农业大学学报(自然科学版)》2004,19(4):440-447
在前文已指出了现代养蜂业存在的问题。一方面,蜂群生产负担过重,造成蜂产品的质量下降。为了解决这个问题,提出根据蜜蜂本身具备的生物学能力,必须恢复自然养蜂的想法。另一方面,养蜂是一种产业,因此,做好生产附加价值比较高的蜂产品是很重要的。因此本文介绍关于提高蜂王浆所具有的抗酸化作用,应用蜂王浆抗菌物质的转基因代替生产,以及作者最新的基础研究成果,提出了自然养蜂与近代科学技术的关系,以及养蜂学和养蜂产业的展望。 相似文献
57.
This study is based on research of throughfall formation and soil chemistry processes. Through the experimental verification of the cation exchange part of the simulation model; making use of results of the flux of acid deposition on the forest and the chemical weathering of soil mineral, we predicted the future soil acidification. The result indicated that chemical weathering occupies the important portion of acid neutralization capacity of the soil and that significant soil acidification will not occur in this field within 40 years, even if the present acid load continues in the future. 相似文献
58.
Kotani A Miyaguchi Y Tomita E Takamura K Kusu F 《Journal of agricultural and food chemistry》2004,52(6):1440-1444
Voltammetric determination of acids by means of the electrochemical reduction of quinone was applied to high-performance liquid chromatography (HPLC) with electrochemical detection (ED) for determining organic acids in fruit wines. A two-channel HPLC-ED system was fabricated by use of an ion-exclusion column and an electrochemical detector with a glassy carbon working electrode. Aqueous solution of 0.1 mM HClO(4) and ethanol containing 2-methyl-1,4-naphthoquinone served as a mobile phase and reagent solution, respectively. Determination of acetic, citric, lactic, malic, succinic, and tartaric acids was made by measuring the peak areas of the flow signals due to the reduction current of quinone caused by the eluted acids. The peak area was found to be linearly related to the acid amount ranging from 0.1 to 40 nmol per 20 microL injection. The present method was characterized by reproducibility with the simple and rapid procedure without derivatization of analytes. The method was shown as an effective means for following acid contents in fruit juices during fermentation with wine yeast. 相似文献
59.
日本现代设施园艺的节能对策及措施 总被引:1,自引:0,他引:1
全球范围内的石油价格上涨,给日本这个依赖能源进口的国家带来了很大的影响,特别是在现代设施园艺生产领域。因此近几年来日本从各级政府、科研机构、学校、企业,以及到生产农户,都对生产节能问题给予了高度重视,对于各种可能的节能对策及措施,政府从政策上予以支持,产学研各部门从技术、设备上予以研究和推广,从而既保障了有效的节能效果、又保障了产品的质量以及农户的经济收入。本文着重介绍了日本近年来采取的主要节能对策和目前比较关注的节能措施.以期为我国节能型设施园艺的发展提供借鉴。 相似文献
60.