全文获取类型
收费全文 | 94篇 |
免费 | 6篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 5篇 |
2013年 | 10篇 |
2012年 | 6篇 |
2010年 | 3篇 |
2008年 | 3篇 |
2007年 | 2篇 |
2006年 | 2篇 |
2004年 | 3篇 |
2003年 | 1篇 |
2002年 | 4篇 |
2000年 | 2篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 5篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
1962年 | 4篇 |
1959年 | 3篇 |
1958年 | 2篇 |
1953年 | 1篇 |
1950年 | 1篇 |
1943年 | 5篇 |
1941年 | 2篇 |
1940年 | 4篇 |
1939年 | 1篇 |
1938年 | 2篇 |
1934年 | 1篇 |
排序方式: 共有100条查询结果,搜索用时 144 毫秒
31.
Riccardo Porcari Christos Proukakis Christopher A. Waudby Benedetta Bolognesi P. Patrizia Mangione Jack F. S. Paton Stephen Mullin Lisa D. Cabrita Amanda Penco Annalisa Relini Guglielmo Verona Michele Vendruscolo Monica Stoppini Gian Gaetano Tartaglia Carlo Camilloni John Christodoulou Anthony H. V. Schapira Vittorio Bellotti 《The Journal of biological chemistry》2015,290(4):2395-2404
The conversion of α-synuclein from its intrinsically disordered monomeric state into the fibrillar cross-β aggregates characteristically present in Lewy bodies is largely unknown. The investigation of α-synuclein variants causative of familial forms of Parkinson disease can provide unique insights into the conditions that promote or inhibit aggregate formation. It has been shown recently that a newly identified pathogenic mutation of α-synuclein, H50Q, aggregates faster than the wild-type. We investigate here its aggregation propensity by using a sequence-based prediction algorithm, NMR chemical shift analysis of secondary structure populations in the monomeric state, and determination of thermodynamic stability of the fibrils. Our data show that the H50Q mutation induces only a small increment in polyproline II structure around the site of the mutation and a slight increase in the overall aggregation propensity. We also find, however, that the H50Q mutation strongly stabilizes α-synuclein fibrils by 5.0 ± 1.0 kJ mol−1, thus increasing the supersaturation of monomeric α-synuclein within the cell, and strongly favors its aggregation process. We further show that wild-type α-synuclein can decelerate the aggregation kinetics of the H50Q variant in a dose-dependent manner when coaggregating with it. These last findings suggest that the precise balance of α-synuclein synthesized from the wild-type and mutant alleles may influence the natural history and heterogeneous clinical phenotype of Parkinson disease. 相似文献
32.
LILIAN JÄRVEKÜLG JÜRI SõBER RIIVO SINIJÄRV INDREK TOOTS MART SAARMA 《The Annals of applied biology》1989,114(2):279-291
Mouse monoclonal antibodies (MAbs) specific for potato virus M (PVM) were prepared and the properties of three of them were studied. MAb M4C1 is IgG2b, it binds with high affinity to PVM coat protein, to purified virus preparations and recognises PVM in infected potato leaves and tubers. MAb M6D5 is IgG2a and also reacts with PVM coat protein, purified PVM and with PVM in potato leaf and tuber extracts. In double-antibody sandwich ELISA (DAS ELISA) MAbs M4C1 and M6D5 reacted with all 17 PVM isolates tested. MAb M7 is IgG2b and recognises PVM only in indirect dot ELISA on nitrocellulose filters and viral coat protein on Western blots. MAbs against PVM were used as capture antibodies and europium-labelled MAbs as conjugates in time-resolved fluoroimmunoassay (EuTRFIA). The standard EuTRFIA curve of PVM detection is approximately linear over a range of PVM concentrations from 0.5 ng/ml to 1000 ng/ml. The lowest PVM concentration detectable in EuTRFIA was 0.5 ng/ml and correspondingly 6 ng/ml in DAS ELISA. The use of the europium chelate label allows PVM detection in potato leaf and tuber sap at dilutions greater than 10--4 with very low background fluorescence. EuTRFIA with MAbs, with either one or two incubations is about 10–20 times more sensitive for PVM detection than is DAS ELISA. PVM and PVX, mixed with healthy potato tuber sap, were simultaneously tested in a single sample at concentrations lower than 10 ng/ml by double-label TRFIA using europium-labelled MAbs to PVM and samarium-labelled MAbs to PVX. 相似文献
33.
Summary Communication about a new habitat of species ofMicroascus as they can grow on paper.It has been shown thatM. intermedius, M. trigonosporus, M. cirrosus can apparently grow and fructificate on paper.M. longirostris showed lesser growth.Cf. Cellulosa e Carta in Boll. dell 'Ente Nazionale per la Cellulosa la Carta. 相似文献
34.
Summary Having experimented the juglone in its antibiotic action it has been seen that such an action manifests itself very weackly towards the Schizomycetes. No action it acts towards yeasts, and mycelium fungi including phytopatogenus fungi (against what has been adfirmed by others precedently). 相似文献
35.
Ivan Scotti Anna Mariani Valentino Verona Alberto Candolini Carlo A Cenci Angelo M Olivieri 《Génome》2002,45(2):222-228
Molecular, cytological, and morphological data support the existence of a hybrid population between Schoenus nigricans and Schoenus ferrugineus. This population was found in northeastern Italy, where S. nigricans is central with respect to its natural range and S. ferrugineus is marginal, being most common in the Alps and in central and northern Europe. Molecular marker data show that the putative hybrid population is genetically intermediate between nearby populations of the parent species. Cytological evidence confirmed the hybrid nature of this population, as does the almost complete sterility of plants within the population. Although no seeds were produced by the hybrid population, some possibly fertile pollen grains were produced; this suggests that the possibility of introgression between the two species through the hybrids cannot completely be excluded. 相似文献
36.
Onorato Verona 《Archives of microbiology》1934,5(1):328-337
Zusammenfassung Es wurde ein oberitalienischer Moorboden aus dem Po-Tal mikrobiologisch untersucht. Die Keimzahl ist sehr niedrig; es handelt sich im wesentlichen um Pilze. Ammoniakbildungs- und Stickstoffbindungs-vermögen sind gering, das Nitrifikationsvermögen ist fast Null. Denitrifikations- und CO2-Bildungsvermögen sind dagegen hoch. 相似文献
37.
Spermiogenesis in Urastoma cyprinae (Graff. 1882) involvcs a progressive lengthening of the spermatid. Free flagella are only transitory. The mature spermatozoon is fusibrm. 45μm in length and 2.5 μm in width. It contains two incorporated axonermes of the flatworm 9+"1" pattern, two elongated mitochondria. an elongated nucleus and a row or cortical longitudinal microtubules. Observations on oogenesis concerncd only the immuturc ovary. lmmature oocytes contain few dense granules and accssory cells were not ohserved. Phylogenetic implications of a biflagellate spermatozoon in a Prolecithophora are important. The presence of two 9 +"1" axonemes confirms that Urastoma (and the Prolecithophora) belongs to the taxon Trepaxonemata Ehlers. Previous electron microscope studies on spermitozoa of Prolecithophora (four genera) only dealt with aflagellate spermatozoa. On this basis, Ehlers (1985) proposed two autapomorphics for the taxon Prolecithophora: aflagellate spermatozoon and spermatozoal mitochondrial derivatives with abundant membranes. The present observations on Urastoma contradict these two autapomorphics. The taxon Prolecithophora cannot be defined by autapomorphies of the spermatozoon. 相似文献
38.
39.
40.
E2F activity is regulated by cell cycle-dependent changes in subcellular localization. 总被引:24,自引:8,他引:16 下载免费PDF全文
R Verona K Moberg S Estes M Starz J P Vernon J A Lees 《Molecular and cellular biology》1997,17(12):7268-7282