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191.
Sergio Giunta 《Immunity & ageing : I & A》2006,3(1):12
The low-grade, chronic, systemic inflammatory state that characterizes the aging process (inflammaging) results from late
evolutive-based expression of the innate immune system. Inflammaging is characterized by the complex set of five conditions
which can be described as 1. low-grade, 2. controlled, 3. asymptomatic, 4. chronic, 5. systemic, inflammatory state, and fits
with the antagonistic pleiotropy theory on the evolution of aging postulating that senescence is the late deleterious effect
of genes (pro-inflammatory versus anti-inflammatory)that are beneficial in early life. Evolutionary programming of the innate
immune system may act via selection on these genetic traits. Here I propose that the already acquired knowledge in this field
may pave the way to a new chapter in the pathophysiology of autoimmunity: the auto-innate-immunity syndromes. Indeed, differently
from the well known chapter of conventional autoimmune diseases and syndromes where the main actor is the adaptive immunity,
inflammaging may constitute the subclinical paradigm of a new chapter of autoimmunity, namely that arising from an autoimmune
inflammatory response of the innate-immune-system, an old actor of immunity and yet a new actor of autoimmunity, also acting
as a major determinant of elderly frailty and age-associated diseases. 相似文献
192.
JOHANNES STÖKL PHILIPP M. SCHLÜTER TOD F. STUESSY HANNES F. PAULUS RAPHAELO FRABERGER DIRK ERDMANN CLAUDIA SCHULZ WITTKO FRANCKE GÜNTER ASSUM MANFRED AYASSE 《Biological journal of the Linnean Society. Linnean Society of London》2009,98(2):439-451
Ophrys orchids mimic the female sex pheromones of their pollinator species to attract males for pollination. Reproductive isolation in Ophrys is based on the selective attraction of only a single pollinator species. A change of floral odour can result in the attraction of a new pollinator species that acts as an isolation barrier towards other sympatrically occurring Ophrys species. Ophrys lupercalis, Ophrys bilunulata, and Ophrys fabrella grow sympatrically and bloom consecutively on Majorca and are pollinated by three species of Andrena. We investigated variation of phenotypic and genotypic flower traits, aiming to study the role of the floral odour for reproductive isolation and speciation. Using chemical and electrophysiology (gas chromatography coupled with an electroantennographic detector) methods, we show that the three Ophrys species use the same odour compounds for pollinator attraction, but in different proportions. A comparison of the floral odour bouquets in a multivariate analysis revealed a clear grouping of plants from the same species, although with an overlap between species. A comparison of the same plants using molecular markers gave a contrasting result. Although O. lupercalis and O. fabrella were genetically well separated, plants of O. bilunulata did not form a distinct group but were similar to either O. lupercalis or O. fabrella. Our data indicate gene flow and hybridization to occur between O. bilunulata and O. lupercalis as well as between O. bilunulata and O. fabrella. All plants of O. bilunulata, despite having different genotypes, showed a very similar floral odour. This reflects a strong selective pressure by the pollinating males. The overlap of genotypes of O. bilunulata and O. fabrella supports our hypothesis that O. fabrella diverged from O. bilunulata by scent variation and the attraction of a new pollinator species, Andrena fabrella. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 439–451. 相似文献
193.
194.
Surface-spread spermatocytes of the fallow deer were examined by light microscopy after silver staining. The development and behaviour of synaptonemal complexes and the partial synapsis of the X and Y chromosomes were investigated during leptotene to diplotene chromosome pairing. 相似文献
195.
Bioactive compounds produced by cyanobacteria 总被引:7,自引:0,他引:7
Cyanobacteria produce a large number of compounds with varying bioactivities. Prominent among these are toxins: hepatotoxins such as microcystins and nodularins and neurotoxins such as anatoxins and saxitoxins. Cytotoxicity to tumor cells has been demonstrated for other cyanobacterial products, including 9-deazaadenosine, dolastatin 13 and analogs. A number of compounds in cyanobacteria are inhibitors of proteases — micropeptins, cyanopeptolins, oscillapeptin, microviridin, aeruginosins- and other enzymes, while still other compounds have no recognized biological activities. In general cyclic peptides and depsipeptides are the most common structural types, but a wide variety of other types are also found: linear peptides, guanidines, phosphonates, purines and macrolides. The close similarity or identity in structures between cyanobacterial products and compounds isolated from sponges, tunicates and other marine invertebrates suggests the latter compounds may be derived from dietary or symbiotic blue-green algae. 相似文献
196.
Carmelina Magnani Laura Cremonesi Annamaria Giunta Paola Magnaghi Roberto Taramelli Maurizio Ferrari 《Human genetics》1996,98(1):102-108
In the cystic fibrosis conductance transmembrane regulator (CFTR) gene a few small deletions and only a large, complex, 50-kb
deletion have been described so far. We report a second large deletion, which had been hypothesized in a patient affected
by cystic fibrosis on the basis of an abnormal pattern of inheritance of the intragenic microsatellites IVS17b/TA and IVS17b/CA.
Southern blot analysis revealed the presence of an anomalous band in the patient and her father, in the region encompassing
exons 13 – 19, approximately 0.6 kb shorten than the one present in normal controls, in addition to the band of the correct
size. Cloning and sequencing the DNA fragments spanning the region of interest demonstrated the presence of a 703-bp deletion
causing complete removal of exon 17b in the paternal cystic fibrosis chromosome. This analysis revealed the presence of two
short direct repeats flanking the breakpoints. The 3′ repeat partially overlapped the IVS17b/CA microsatellite and the number
of CA repeated units present in the paternal cystic fibrosis allele was the shortest ever found among chromosomes so far analyzed.
These data may suggest that the mechanism for the generation of the deletion may have involved a slipped mispairing during
DNA replication, which has not previously been described in the CFTR gene.
Received: 27 December 1995 / Accepted: 30 January 1996 相似文献