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1.
采用脱氨再生几丁质凝胶亲和层析从萝卜叶中获得了PAGE圆盘电泳均一的溶菌酶,并通过微量蒸发扩散法获得其结晶。用pH动力学研究方法和化学修饰法对该酶的活性中心进行了初步研究,实验结果表明:-COOH(Glu/Asp)基团、Trp及His残基可能为酶活性所必需。采用对Tyr、Cys、Arg、Ser/Thr残基专一的修饰剂对酶作用后,酶活性基本上不受影响。同时,酶活性受到组胺和GlcNAc抑制。讨论了萝卜溶菌酶与鸡蛋清溶菌酶和木瓜溶菌酶的活性中心的相互差异。 相似文献
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Lopes LP Pimpão DM Takemoto RM Malta JC Varella AM 《Journal of invertebrate pathology》2011,106(3):357-359
Larvae of Hysterothylacium use various invertebrates as intermediate hosts. Definite hosts include fish, birds, reptiles or marine mammals. This study describes the occurrence of Hysterothylacium (Nematoda, Anisakidae) larvae parasitizing the pericardic cavity of Diplodon suavidicus (Unioniformes, Hyriidae) specimens collected in the Amazon basin, Brazil. This is the first record of this nematode parasitizing freshwater bivalves in South America. The high prevalence, medium intensity and medium abundance suggest that D. suavidicus acts as intermediate host for Hysterothylacium species in that environment. 相似文献
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The number of species in the freshwater mussel genus Cristaria Schumacher, 1817 recognized from Far East Russia has varied over the last several decades. While some authors consider the occurrence of only one species, Cristaria plicata (Leach, 1815), widespread in East Asia, others, recognize two separate species Cristaria herculea (Middendorff, 1847) and Cristaria tuberculata Schumacher, 1817 from Far East Russia, distinct from C. plicata. For the present study, freshwater mussels, identified as C. herculea, were collected in the Upper Amur basin (Transbaikalia, Russia). The shell morphology and the whole soft body anatomy were analysed in detail and compared with previously published information on other Cristaria spp.. Additionally, a cytochrome oxidase subunit 1 (CO1) gene fragment was sequenced from foot tissue samples of selected animals, collected from the same region, and compared with published data. Based upon morphological similarities of glochidia and adult morphology and anatomy as well as the mitochondrial DNA sequence analysis, we consider C. herculea as a synonym of C. plicata. Further analysis of Far East Russia C. herculea and C. tuberculata specimens using both molecular and morphological characters should be carried in the future to enhance our knowledge about the taxonomy within the Cristaria genus. Moreover, a comprehensive revision of the genus Cristaria is needed, restricting the type locality and comparing topotypic specimens for both C. plicata and C. tuberculata, and including all recognized Cristaria species. 相似文献
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Huidong Li Hao Feng Weiguo Sun Qunchao Fan Yaoming Xie R. Bruce King Henry F. Schaefer III 《Journal of molecular modeling》2013,19(7):2723-2737
The bis(heptalene)dimetal complexes (C12H10)2M2 of the first row transition metals from Ti to Ni are predicted by density functional theory to exhibit “submarine” sandwich structures with a pair of metal atoms sandwiched between the two heptalene rings. For the early transition metal derivatives (C12H10)2M2 (M = V, Cr) there are two types of such structures. In one structural type the metals are sandwiched between two heptahapto heptalene rings with metal-metal distances (3.5–3.8 Å) too long for direct metal-metal bonding. The other type of (C12H10)2M2 (M = V, Cr, Mn) structure has a pair of bonded metal atoms sandwiched between a fully bonded heptalene ligand and a heptalene ligand bonded to the metals only through an eight-carbon heptafulvene subunit, leaving an uncomplexed cis-1,3-diene unit. The formal metal-metal bond orders in these latter structures are 3, 2, and 1 for M = V, Cr, and Mn with predicted bond lengths of 2.5, 2.7, and 2.8 Å, respectively. For (C12H10)2Fe2 a singlet structure with each iron atom sandwiched between a hexahapto and a tetrahapto heptalene ring is energetically preferred over an alternate structure with ferrocene-like iron atoms sandwiched between two pentahapto heptalene rings. Partial bonding of each heptalene ring to the metal atoms occurs in the late transition metal derivatives (C12H10)2M2 (M = Co, Ni). This leads to an unsymmetrical structure for the cobalt derivative and a structure for the nickel derivative with each nickel atom sandwiched between a trihapto ligand and a tetrahapto ligand. Figure
The bis(heptalene) dimetal complexes (C12H10)2M2 (M = Ti to Ni) are predicted by density functional theory to have a “submarine” sandwich structure with a pair of metal atoms sandwiched between the two heptalene rings. In the early transition metal derivatives (C12H10)2M2 (M = V, Cr) the metal atoms are sandwiched between two heptahapto heptalene rings. In contrast, for (C12H10)2M2 (M = Mn, Fe, Co, Ni) the heptalene rings are only partially bonded to the metal atoms. 相似文献
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The seasonal distribution of Acanthocephalus tumescens (Acanthocephala : Echinorhynchidae) among Galaxias maculatus (Pisces : Galaxiidae) in Lake Gutiérrez was studied from March 1994 to June 1996. Acanthocephalus tumescens always occurs in the intestine, has an overdispersed frequency distribution, a similar proportion of sexes, and females are larger than males. Mean intensity and prevalence are low and increase with host length. The pattern of the infection shows seasonality, with recruitment in winter and a reproductive period during spring-summer. 相似文献
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Jhillu Singh Yadav Kamani Satyanarayana Pamu Sreedhar Pabbaraja Srihari Thokhir Basha Shaik Shasi Vardhan Kalivendi 《Bioorganic & medicinal chemistry letters》2010,20(12):3814-3817
The racemic total synthesis of elegansidiol, farnesiferol B, and farnesiferol D has been obtained following a Diels–Alder approach. Gillman addition, cross metathesis reaction are the other key steps involved in the target synthesis. 相似文献
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The mammalian fauna from Gülpinar (Canakkale, Turkey), dated Turolian, comprises threeHipparion taxa:H. cf.matthewi, H. sp. medium-sized, andH. sp. large. Two metatarsals may represent a fourth taxon or may derive from a different locality. The hipparion material is described here. 相似文献
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Kaur K Jain M Khan SI Jacob MR Tekwani BL Singh S Singh PP Jain R 《Bioorganic & medicinal chemistry》2011,19(1):197-210
In continuing our search of potent antimalarials based on 8-aminoquinoline structural framework, three series of novel bis(8-aminoquinolines) using convenient one to four steps synthetic procedures were synthesized. The bisquinolines were evaluated for in vitro antimalarial (Plasmodiumfalciparum), antileishmanial (Leishmaniadonovani), antimicrobial (a panel of pathogenic bacteria and fungi), cytotoxicity, ??-hematin inhibitory and methemoglobin (MetHb) formation activities. Several compounds exhibited superior antimalarial activities compared to parent drug primaquine. Selected compounds (44, 61 and 79) when tested for in vivo blood-schizontocidal antimalarial activity (Plasmodiumberghei) displayed potent blood-schizontocial activities. The bisquinolines showed negligible MetHb formation (0.2-1.2%) underlining their potential in the treatment of glucose-6-phosphate dehydrogenase deficient patients. The bisquinoline analogues (36, 73 and 79) also exhibited promising in vitro antileishmanial activity, and antimicrobial activities (43, 44 and 76) against a panel of pathogenic bacteria and fungi. The results of this study provide evidence that bis(8-aminoquinolines), like their bis(4-aminoquinolines) and artemisinin dimers counterparts, are a promising class of antimalarial agents. 相似文献
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Vásquez LR Galvão C Pinto NA Granados H 《Biomédica : revista del Instituto Nacional de Salud》2005,25(3):417-421
The presence of Triatoma nigromaculata was recorded for the first time in Colombia in the rural village La Playa in the province of Cauca. A single female was captured from an outdoor area near a household. The presence of Trypanosoma parasites in the specimen was not established due to the poor condition of the specimen. The epidemiological importance of this finding is discussed with respect to the potential for transmission of Chagas disease in the province of Cauca and, more broadly, in Colombia. 相似文献
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对中国薇(蟾)属Pachyscia Redtenbacher进行了分类整理,共计5种,含1新种,海南薇螨Pachyscia hainanensis sp.nov.;描述了属征,编制了中国已知种检索表.新种模式标本保存于广州中山大学生物博物馆. 相似文献
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Male karyotype and meiosis of Tenagobia fuscata (Corixoidea, Micronectidae) are studied. The species possesses a male diploid chromosome number 2n = 28 + XY, holokinetic chromosomes, absence of m chromosomes and an achiasmatic male meiosis. Autosomes divide pre-reductionally while the sex chromosomes do so post-reductionally. Banding techniques (C, DAPI and CMA) show that large heterochromatic AT-GC rich bands are generally terminally located, although some interstitial bands are also detected. Many bivalents are heteromorphic for heterochromatin amount and location. This is the first report of a species with achiasmatic male meiosis within the Nepomorpha. These cytogenetic features markedly differ from all previous reports for 26 species of the superfamily Corixoidea. T. fuscata occurs in permanent shallow water bodies, and most known individuals are brachypterous. Their dispersion depends on occasional floodings of the water bodies they occupy. Since achiasmatic meiosis maintains groups of co-adapted genes, this feature could be an adaptive strategy of the species to the particular type of habitat and ecological niche it occupies. 相似文献
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Lineus viridis is a common nemertean species of North-Atlantic intertidal sand flats. Its mating behaviour is peculiar insofar as this species is reported to be polyandric. However, detailed information on this topic is lacking. In order to get more data on the reproduction, oogenesis and life history of this species, a population in the Wadden Sea on the Isle of Sylt (North Sea) was studied between 2005 and 2011. We conducted regular surveys, during which we sampled, measured and recorded the sex status of 25–100 individuals at each sampling event; at least three individuals were fixed for histological studies at each sampling date. In addition, animals were kept in the laboratory for 3?years to complement field data on sexual identity. Lineus viridis was found to reproduce annually in several successive year; the females are significantly larger than the males. Oogenesis starts in spring, shortly after the preceding reproductive period, and continues until the end of December. Spermiogenesis starts in late autumn and also ends late in December. During mating, several males are generally found crawling on a single female, which forms a cocoon that encloses both the female and the associated males. Fertilization is internal. While females discharge all of their eggs during a single mating event and lose more than 40% of their wet weight, males only empty a few of their gonads, and are thus able to fertilize more than one female. Our study clearly shows that Lineus viridis is a perennial, iteroparous species with a pronounced sexual size dimorphism. During this long-term study, no evidence for sequential hermaphroditism has been found. The observed polyandric mating system in this species raises further questions regarding mate and sperm competition that deserve additional research. 相似文献
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Priv.-Doz. Dr. Erwin Tretzel 《Zoomorphology》1961,50(4):375-542
Ohne ZusammenfassungZweiter Teil der Habilitationssehrift. 相似文献
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Aedes(S.)scutellaris(Walker,1859)(盾纹伊蚊)过去在我国台湾、广东、云南等地都有记载。现知其指名亚种s.scutellaris为巴布亚种类,分布于印度尼西亚和新几内亚。最近我们检视了广东和云南的本种标本,发现它们实系另一亚种,即scutellaris malayensis Colless,1962。它与指名亚种的外表十 相似文献
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王玉琳 《微生物学免疫学进展》1994,(3)
生物制品GMP(WHO,1992)目录1.本指南范围2.原则3.人员4.厂房和设备5.动物设施及管理6.生产7.标签8.批加工记录(格式)和分发记录9.质量保证和质量控制1本指南范围本指南系作为《药品GMP》(见WHOTRS,NO.823)的补充。生... 相似文献
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正山茶象Curculio chinensis(Chevrolat,1878),又名油茶象甲、茶籽象甲,隶属于鞘翅目(Coleoptera)、象虫科(Curculionidae)。体长6.7-8.0 mm,体壁黑色,覆盖白色和黑褐色鳞片。前胸背板两侧基部和小盾片的白色鳞片密集,鞘翅的白色鳞片排列成不规则斑点,中间之后有1横带,腹面完全散布白毛。喙细长,雌虫喙长几乎等于体长,触角着生于喙基部1/3处,雄虫喙较短,为体长的2/3,触 相似文献