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31.
《Biological conservation》2002,106(3):365-372
The lizard Zootoca vivipara has both oviparous and viviparous populations which belong to distinct clades. This study aims to elucidate the geographic distribution, phylogeography and conservation priority of the oviparous subspecies, Zootoca vivipara carniolica, that has recently been identified in Slovenia. We studied seven Slovenian populations, two northeastern Italian populations and five northwestern Italian populations. The seven cytochrome b haplotypes that we identified from the Slovenian and Italian oviparous populations form a monophyletic basal clade. The high homogeneity of the Slovenian and northeastern Italian populations (nucleotide diversity π=0.06%) is a striking contrast with the pattern observed in northwest Italy where each of the five populations studied presents a private haplotype (π=1.03%). The results obtained suggest that all the extant lineages of Z. v. carniolica have originated in an Italian refuge. The reproductive and phylogenetic distinctiveness of Z. v. carniolica clearly justifies conservation of its populations, especially in Italy where the highest genetic diversity and the most ancestral haplotype were observed. 相似文献
32.
To investigate the action of dinotefuran (MTI-446, 1-methyl-2-nitro-3-(tetrahydro-3-furylmethyl)guanidine), a recently developed insecticide, on insect nicotinic acetylcholine receptors (nAChRs), we determined the potencies of the compound and 15 analogues in inhibiting the specific binding of [3H]epibatidine (EPI), a nAChR agonist, and [3H]alpha-bungarotoxin (alpha-BGT), a competitive nAChR antagonist, to the nerve cord membranes of American cockroaches (Periplaneta americana). Racemic dinotefuran inhibited [3H]EPI binding with an IC50 of 890 nM and [3H]alpha-BGT binding with an IC50 of 36.1 microM. Scatchard analysis indicated that the dinotefuran inhibition of [3H]EPI binding was a competitive one. Slight structural modification caused a drastic reduction in potency; only four analogues were found to be equipotent to or more potent than dinotefuran. Chloropyridinyl and chlorothiazolyl neonicotinoid insecticides displayed two or three orders of magnitude higher potency than dinotefuran. There was a good correlation between the IC50 values of tested compounds obtained with [3H]EPI and those obtained with [3H]alpha-BGT. A better correlation was observed between 3-h knockdown activities (KD50) against German cockroaches (Blattella germanica) and IC50 values obtained from [3H]EPI assays than between 24-h lethal activities (LD50) and IC50 values. While the results indicate that dinotefuran and its analogues interact with the ACh-binding site in cockroach nAChRs, it remains to be elucidated why they displayed lower potencies than those expected based on their insecticidal activities. 相似文献
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35.
Strobilurin类杀菌剂作用靶标的研究进展 总被引:12,自引:4,他引:12
Strobilurin类杀菌剂是在具有杀菌活性的天然β-甲氧基丙烯酸酯衍生物的基础上研发出来的,具有广谱、高效、安全的特点。主要以粘噻唑为例综述了该类杀菌剂作用靶标及作用位点的研究过程及最新进展。生化作用机理的研究明确了粘噻唑作用于线粒体呼吸链bc1复合物中的细胞色素b及铁硫蛋白,阻止了从细胞色素b到细胞色素c1的电子传递,从而抑制线粒体的呼吸作用;蛋白质晶体学研究明确了粘噻唑的作用位点(Qo位点)是通过氢键与铁硫蛋白及细胞色素b的残基结合的。其他strobilurin类杀菌剂和粘噻唑具有相同的靶标,但由于各化合物之间存在一定的结构差异,其具体作用位点亦有一定的差别。 相似文献
36.
AIM: To explore the effect of the pretreatment of hypertonic saline (HTS) in hepatic ischemia reperfusion (I/R) injury.METHODS: The rats were divided into sham group (sham group), ischemia reperfusion group (IR group) and pretreatment of hypertonic saline group (HTS group). Partial hepatic ischemia reperfusion model was used. The rats were sacrificed at the time of 1 h, 3 h, 6 h, 12 h and 24 h after reperfusion in each group, respectively. Blood samples were obtained to examine ALT. The expression of the CD11b/CD18 (Mac-1) on the neutrophils was analyzed by flow cytometry. RT-PCR and Western blotting were used to examine the expression of intercellular adhesion molecule-1 (ICAM-1) in livers and chromatometry was performed to detect the activity of myeloperoxidase (MPO) in livers. The morphology of hepatocytes and the structure of sinusoid were observed by histological examinations. RESULTS: ① HTS pretreatment decreased the level of ALT at the time points of 3 h, 6 h and 12 h after reperfusion (P<0.05). ② Mac-1 expression in HTS group was lower at 6 h and 12 h after reperfusion compared with IR group (P<0.05). ③ MPO activity in HTS group was lower at 6 h, 12 h and 24 h compared with IR group (P<0.05). ④ RT-PCR and Western blotting analysis indicated that the pretreatment of HTS inhibited the expression of ICAM-1 in livers after reperfusion. ⑤ Moderate hepatocyte swelling and few neutrophil infiltration were observed in HTS group.CONCLUSION: Pretreatment with HTS has the effect on hepatic ischemia reperfusion injury by inhibiting the expression of Mac-1 on circulating neutrophils and the expression of ICAM-1 in the liver. 相似文献
37.
应用红细胞C3b受体花环(C3bRR)和免疫复合物花环(ICR)试验,证实鸵鸟红细胞表面存在补体C3b受体(C3breceptor,C3bR),表明红细胞免疫系统(Rcdcelimmunesystem,RCIS)的概念亦适用于这种动物;鸵鸟红细胞不但有传统医学观念上的功能,而且还可借助CR1(ComplementreccptortypeI)进行免疫粘附,并以此为基础,表现出各种重要的免疫功能。 相似文献
38.
A new sesquiterpene lactone, 7alpha,10alpha-epoxy-1alpha(H),5alpha(H)-guaia-3,11(13)-dien-8alpha,12-olide, was isolated from the leaves of Hedyosmum arborescens. The structure of this unusual 7,10-epoxy-guaianolide was determined by spectroscopic methods, particularly one- and two-dimensional 1H and 13C NMR. 相似文献
39.
The spectral data of a new Δ7,22 sterol, 24S-ethyl-5α-cholesta-7,22E-dien-3α-ol β-galactopyranoside, isolated from the bulbs of Autonoë madeirensis, are reported. 相似文献
40.
The content of the glyceraldehyde-2-aryl ether-type structure in water-soluble lignin–carbohydrate complex (LCC) fractions, which were obtained from Japanese cedar and birch residual wood meal after milled wood lignin isolation, was determined by ozonation. Quite high amounts of the glyceraldehyde-2-aryl ether-type structure were found in water-soluble LCC fractions of both species; about 3–5 times higher than those of other fractions. This result, as well as the high content of the β-1 structure in these fractions shown in our previous reports, suggest that lignin in these fractions has the characteristics of endwise-type lignin, because the glyceraldehyde-2-aryl ether-type structure and β-1 structure are typical characteristics of this type of lignin fraction. These results are in good agreement with the generally accepted hypothesis that the glyceraldehyde-2-aryl ether-type structure and β-1 structure are generated at the same time by a radical coupling reaction. The results also indicated that these two structures are present in close proximity in the lignin. 相似文献