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1.
在长江沙洲上搁浅的中华白海豚   总被引:5,自引:0,他引:5  
在长江沙洲上搁浅的中华白海豚STRANDINGOFANINDO┐PACIFICHUMP┐BACKEDDOLP┐HINONASANDBANKINTHEYANGTZERIVER中华白海豚(Sousachinensis,Osbeck)分布在西太平洋和印度...  相似文献   

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蚯蚓体内一种纤溶酶原激活剂(e-PA)对BAEE的降解   总被引:2,自引:0,他引:2  
以苯甲酰-L-精氨酸乙酯(benzoyl-L-arginineethylester,BAEE)为底物,研究了蚯蚓体内纤溶酶原激活剂(plasminogenactivatorfromEiseniafetida,e-PA)的酶学性质.酶促反应的最适pH为8.4,e-PA降解BAEE的Km为1.24±0.16×10-5mol/L,Kcat为13.80±4.02s-1.测定了构成e-PA的大,小亚基分别降解BAEE的Km和Kcat.结果表明,大亚基的Km与全酶的Km相差不多,但比小亚基小约10倍,即对底物的亲和力比小亚基强约一个数量级.大小亚基的Kcat比较接近,分别是全酶的1/6和1/3.研究了8种抑制剂对e-PA降解BAEE活性的影响,其中pepstatin和E-64(一种巯基抑制剂)对酶促反应有激活作用,TPCK,TL-CK,PMSF,chymostatin和leupeptin对其有不同程度的抑制作用,EDTA对e-PA的活性没有影响.对e-PA的BAEE活性和e-PA的纤溶活性之间作了比较.  相似文献   

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符国瑷   《广西植物》1994,14(4):301-302
中国锥属一新种符国瑷(海南省林业局标本室,海口570003)关键词锥属;波叶锥ANEWSPECIESOFCASTANOPSISBL.FROMCHINA¥FuGnoai(ForestryBureauofHainan,Haikou570003)Keywo...  相似文献   

4.
前列腺素对肺泡巨噬细胞分泌白细胞介素—8的调控   总被引:2,自引:0,他引:2  
本实验在经血清调理酵母聚糖激活的大鼠肺泡巨噬细胞(AM)体外培养4h后,检测其上清液中的PGs含量。消炎痛预处理使激活的AM释放的PGE1、E2、F2a量显著减少,E2/E1和E2/F2a比值降低;而细胞松弛素B预处理AM则可使上述PGs的含量增加。以中性粒细胞趋化指数来反映IL-8的活性,表明消炎痛预处理AM组的IL-8的分泌量显著减少,而细胞松弛素B预处理AM组的IL-8分泌量显著增多。AM的  相似文献   

5.
X. C. ZHANG 《植物研究》1998,18(1):107-117
GENUSANTROPHYUMKAULF.FROMCHINAANDNEIGHBORINGREGIONSX.C.ZHANG(Theherbarium(PE),InstituteofBotany,ChineseAcademyofSciences,Bei...  相似文献   

6.
目的和方法:为探讨血管活性肠肽(VIP)对嗜酸性粒细胞功能的调节,采用密度梯度离心法分离健康志愿者外周血嗜酸性粒细胞(Eos),培养人脐带静脉血管内皮细胞(HUVEC),然后分别与VIP和IL-1β共育,再以血小板激活因子(PAF)活化Eos,用嗜酸性过氧化物酶(EPO)活性评估Eos的过氧化反应和脱颗粒反应,以白细胞单层粘附试验测定Eos和EC之间的粘附作用。结果:VIP能抑制PAF致Eos的E  相似文献   

7.
本实验在经血清调理酵母聚糖激活的大鼠肺泡巨噬细胞(AM)体外培养4h后,检测其上清液中的PGs含量。消炎痛预处理使激活的AM的释放的PGE1、E2、F2a量显著减少,E2/E1和E2/F2a比值降低;而细胞松弛素B预处理AM则可使上述PGs的含量显著增加。以中性粒细胞趋化指数来反映IL-8的活性,表明消炎痛预处理AM组的IL-8的分泌量显著减少,而细胞松弛素B预处理AM组的IL-8分泌量显著增多。AM的PGs释放量与其IL-8分泌量呈平行的变化关系,说明内源性PGs在AM的分泌IL-8的活动中起着调控作用。  相似文献   

8.
将尖吻蝮蛇毒酸性磷脂酶 A2 I( A.a A P L A2 I) 的基因克隆至表达载体p B L M V L2 , 在大肠杆菌 R R1 中成功表达。表达产物 A.a A P L A2 I约占细菌蛋白质总量的30 % , 以包含体的形式存在。纯化包含体后, 将产物变性、复性, 然后用 F P L C Superose T M12 纯化, 产物经过 S D S P A G E 检测只有单一条带。对表达的 A.a A P L A2 I进行了酶活性、抑制血小板聚集活性和溶血活性的测定。结果显示, 表达的 A.a A P L A2 I的酶活性同变性后复性江浙蝮蛇酸性磷脂酶 A2( A P L A2) 的酶活性相近, 既具有抑制血小板聚集活性也具有溶血活性。最后对磷脂酶 A2( P L A2) 的结构与这些活性的关系进行了讨论  相似文献   

9.
云南山茶科新种和新变种*闵天禄(中国科学院昆明植物研究所,昆明650204)NEWSPECIESANDVARIETIESOFTHEACEAEFROMYUNNANMingTienlu(KunmingInstituteofBotany,ChineseAc...  相似文献   

10.
国产多榔菊属两新种陈艺林(中国科学院植物研究所北京100093)TWONEWSPECIESOFDORONICUMLINN.(COMPOSITAE)FROMCHINACHENYiLing(InstituteofBotany,theChineseAc...  相似文献   

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It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.  相似文献   

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Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.  相似文献   

18.
Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.  相似文献   

19.
肝癌中HBV和HCV基因和抗原的分布及意义   总被引:1,自引:0,他引:1  
采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细  相似文献   

20.
For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.  相似文献   

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