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1.
作者在广东省梅县市发现四个吸虫新种:1.鼠丽色吸虫,新种Reesella ratta sp. nov., 2.后囊蛙蠕吸虫,新种Batrachotrema optstosacca sp. nov., 3.梅县后平睾吸虫,新种Opisthioparorchis meixianensis sp. nov., 4.大卵后平睾吸虫,新种Opisthioparorchis megaloonos sp. nov.,它们分别归隶于蹲茎科Cathaemasiidae及蛙蠕科Bstrachotrematidae。模式标本保存于中山医科大学寄生虫学研究所。 相似文献
2.
Conjugation to an antifibrin monoclonal antibody enhances the fibrinolytic potency of tissue plasminogen activator in vitro 总被引:1,自引:0,他引:1
Tissue plasminogen activator (tPA) was covalently linked by disulfide bonds to a monoclonal antibody specific for the amino terminus of the beta chain of fibrin (antibody 59D8). The activity of the tPA-59D8 conjugate was compared with that of tPA, urokinase (UK), and a UK-59D8 conjugate. For lysis of fibrin monomer, tPA was 10 times as potent as UK, whereas both UK-59D8 and tPA-59D8 conjugates were 100 times as potent as UK and 10 times as potent as tPA. Conjugation of tPA or UK to antibody 59D8 produced a 3.2-4.5-fold enhancement in clot lysis in human plasma over that of the respective unconjugated plasminogen activator. However, the UK-59D8 conjugate was only as potent as tPA alone. Antibody-conjugated tPA or UK consumed less fibrinogen, alpha 2-antiplasmin, and plasminogen than did the unconjugated activators, at equipotent fibrinolytic concentrations. Antibody targeting thus appears to increase the concentration of tPA in the vicinity of a fibrin deposit, which thereby leads to enhanced fibrinolysis. 相似文献
3.
Fritz Runge 《Plant Ecology》1969,17(1):151-156
Summary Following the dry year of 1959 considerable damage was done to a number of beeches in a Melico-Fagetum wood in the Drübel area near Brilon (Sauerland). The effects of this damage coupled with the subsequent removal of the affected trees were studied over an 8-year period with a permanent quadrat and revealed the following vegetation cycle: pure or almost pure beechwood — dying or cutting down of single beeches and with it an opening up of the tree canopy — an increase in the abundance and flowering of wild strawberry (Fragaria vesca) and other lightloving species — an increase in the density and growth of sycamore (Acer) and ash (Fraxinus) saplings — a decrease in the amount of wild strawberry and indeed of other light-loving species too because of the increasing shade — development of beech seedlings into young trees under the shadow of the other shrubs and trees — probably a sycamoreash-beech stand — probably a pure or almost pure becchwood again.
Zusammenfassung Das Dürrejahr 1959 verursachte in einem Melico-Fagetum des Drübels bei Brilon erhebliche Schäden an mehreren Buchen. Diese Schäden und die folgende Abholzung der erkrankten Bäume lösten, wie 8jährige Untersuchungen in einem Dauerquadrat ergaben, folgenden Vegetationsyklus aus: Reiner oder fast reiner Buchen-Hochwald — Absterben bzw. Schlag einzelner Buchen und damit Auflockerung der Baumschicht — Vermehrung bzw. Blüte der Walderdbeere und anderer lichtliebender Arten — Verdichtung und schnelles Emporwachsen des Ahorn- und Eschen-Jungwuchses — Abnahme der Erdbeere, wohl auch anderer licht-liebender Arten infolge wieder zunehmender Beschattung — Heranwachsen von Buchen-Keimlingen zu Jungpflanzen, und zwar im Schatten der anderen Sträucher und Bäume — voraussichtlich Ahorn-Eschen-Buchen-Bestand — voraussichtlich wieder reiner oder fast reiner Buchen-Hochwald.相似文献
4.
Antibody-directed fibrinolysis. An antibody specific for both fibrin and tissue plasminogen activator 总被引:3,自引:0,他引:3
C Bode M S Runge E E Branscomb J B Newell G R Matsueda E Haber 《The Journal of biological chemistry》1989,264(2):944-948
An investigation was made to determine whether it is possible to attract tissue plasminogen activator (tPA) to the site of a thrombus by means of an antibody with affinites for both tPA and fibrin. A bispecific antibody conjugate was constructed by cross-linking two monoclonal antibodies: one specific for tPA, the other specific for fibrin. The bispecific antibody enhanced fibrinolysis by capturing tPA at the site of a fibrin deposit. In an in vitro quantitative fibrinolysis assay, the relative fibrinolytic potency of tPA bound to the bispecific antibody was 13 times greater than that of tPA and 200 times greater than that of urokinase. When fibrin was treated with the bispecific antibody before being mixed with tPA, the relative fibrinolytic potency of tPA was enhanced 14-fold. This capture also occurred when the concentration of tPA present in the assay was less than the concentration of tPA present in normal human plasma. In a human plasma clot assay, samples containing both the bispecific antibody and tPA exhibited significantly more lysis than did samples containing tPA alone. In spite of the increased clot lysis effected by the presence of bispecific antibody, there was no significant increase in fibrinogen or alpha 2-antiplasmin degradation at equal tPA concentrations. The ability of the bispecific antibody to concentrate exogenous tPA in vivo was then examined in the rabbit jugular vein model. Systemic infusion of a small amount of tPA (10,000 units) produced no significant increment in thrombolysis over the level of spontaneous lysis (14 +/- 8%). However, the simultaneous infusion of 10,000 units of tPA and 2 mg of bispecific antibody resulted in 42 +/- 14% (p less than 0.01) lysis. These results suggest that a molecule capable of binding both fibrin and tPA with high affinity could enhance thrombolysis in the circulation by capturing endogenous tPA. 相似文献
5.
对我国52种微茎类吸虫的18项成虫形态学特征进行主成分分析,结果表明:卵巢位置、子宫延伸位置等7项性状对第一主成分贡献较大,提示描述器官位置的指标是重要的分类依据。52个虫种在前三个主成分上的排序图显示应将其划分成4个亚科。 相似文献
6.
Substrate-dependent transport of the NADPH:protochlorophyllide oxidoreductase into isolated plastids. 总被引:13,自引:3,他引:10 下载免费PDF全文
The key regulatory enzyme of chlorophyll biosynthesis in higher plants, the light-dependent NADPH:protochlorophyllide oxidoreductase (POR), is a nuclear-encoded plastid protein. Its post-translational transport into plastids is determined by its substrate. The precursor of POR (pPOR) is taken up and processed to mature size by plastids only in the presence of protochlorophyllide (Pchlide). In etioplasts, the endogenous level of Pchlide saturates the demands for pPOR translocation. During the light-induced transformation of etioplasts into chloroplasts, the Pchlide concentration declined drastically, and isolated chloroplasts rapidly lost the ability to import the precursor enzyme. The chloroplasts' import capacity for the pPOR, however, was restored when their intraplastidic level of Pchlide was raised by incubating the organelles in the dark with delta-aminolevulinic acid, a common precursor of tetrapyrroles. Additional evidence for the involvement of intraplastidic Pchlide in regulating the transport of pPOR into plastids was provided by experiments in which barley seedlings were grown under light/dark cycles. The intraplastidic Pchlide concentration in these plants underwent a diurnal fluctuation, with a minimum at the end of the day and a maximum at the end of the night period. Chloroplasts isolated at the end of the night translocated pPOR, whereas those isolated at the end of the day did not. Our results imply that the Pchlide-dependent transport of the pPOR into plastids might be part of a novel regulatory circuit by which greening plants fine tune both the enzyme and pigment levels, thereby avoiding the wasteful degradation of the imported pPOR as well as photodestruction of free Pchlide. 相似文献
7.
本文就萤叶甲亚科中柱萤叶甲属鞘翅具黑色刻点的种类进行研究,共记述4种,我国已记录3种,其中1种为新种。 相似文献
8.
9.
维生素C·Cu·菲咯啉系统对DNA的定位损伤 总被引:4,自引:0,他引:4
维生素C·Cu·菲咯啉系统对DNA的定位损伤柯德森,王爱国,罗广华(中国科学院华南植物研究所,广州510650)关键词活性氧;DNA;定位损伤活性氧对DNA的损伤已经被很多工作所证实”””,这种伤害是由0B”直接作用于DNA所引起的”’“。但是OH’... 相似文献
10.
Maarten Jaap Erik Broekman Selwyn Hoeks Rosa Freriks Merel M. Langendoen Katharina M. Runge Ecaterina Savenco Ruben ter Harmsel Mark A. J. Huijbregts Marlee A. Tucker 《Global Ecology and Biogeography》2023,32(2):198-205