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991.
Debora Levy Thatiana Correa de Melo Beatriz A. Oliveira Jessica L. Paz Fabio A. de Freitas Cadiele O. Reichert Alessandro Rodrigues Sergio P. Bydlowski 《Biochemistry and Biophysics Reports》2019
Oxysterols are 27-carbon oxidation products of cholesterol metabolism. Oxysterols possess several biological actions, including the promotion of cell death. Here, we examined the ability of 7-ketocholesterol (7-KC), cholestane-3β-5α-6β-triol (triol), and a mixture of 5α-cholestane-3β,6β-diol and 5α-cholestane-3β,6α-diol (diol) to promote cell death in a human breast cancer cell line (MDA-MB-231). We determined cell viability, after 24-h incubation with oxysterols. These oxysterols promoted apoptosis. At least part of the observed effects promoted by 7-KC and triol arose from an increase in the expression of the sonic hedgehog pathway mediator, smoothened. However, this increased expression was apparently independent of sonic hedgehog expression, which did not change. Moreover, these oxysterols led to increased expression of LXRα, which is involved in cellular cholesterol efflux, and the ATP-binding cassette transporters, ABCA1 and ABCG1. Diols did not affect these pathways. These results suggested that the sonic hedgehog and LXRα pathways might be involved in the apoptotic process promoted by 7-KC and triol. 相似文献
992.
The putative functional ecology and distribution of archaeal communities in sponges,sediment and seawater in a coral reef environment
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Ana R. M. Polónia Daniel F. R. Cleary Rossana Freitas Nicole J. de Voogd Newton C. M. Gomes 《Molecular ecology》2015,24(2):409-423
Archaea play crucial roles in a number of key ecological processes including nitrification and methanogenesis. Although several studies have been conducted on these organisms, the roles and dynamics of coral reef archaeal communities are still poorly understood, particularly in host and nonhost biotopes and in high (HMA) and low microbial abundance (LMA) sponges. Here, archaeal communities detected in six distinct biotopes, namely, sediment, seawater and four different sponge species Stylissa carteri, Stylissa massa, Xestospongia testudinaria and Hyrtios erectus from the Spermonde Archipelago, SW Sulawesi, Indonesia were investigated using 454‐pyrosequencing of 16S rRNA genes (OTU cut‐off 97%). Archaeal communities from sediment and sponges were dominated by Crenarchaeota, while the seawater community was dominated by Euryarchaeota. The biotope explained almost 75% of the variation in archaeal composition, with clear separation between microbial assemblages from sediment, X. testudinaria and H. erectus (HMA). In contrast, samples from seawater and both Stylissa species (LMA) showed considerable overlap in the ordination and, furthermore, shared most abundant OTUs with the exception of a single dominant OTU specifically enriched in both Stylissa species. Predicted functional gene content in archaeal assemblages also revealed significant differences among biotopes. Different ammonia assimilation strategies were exhibited by the archaeal communities: X. testudinaria, H. erectus and sediment archaeal communities were enriched for glutamate dehydrogenase with mixed specificity (NAD(P)+) pathways, while archaeal planktonic communities were enriched for specific glutamate dehydrogenase (NADP+) and glutamate synthase pathways. Archaeal communities in Stylissa had intermediate levels of enrichment. Our results indicate that archaeal communities in different biotopes have distinct ecophysiological roles. 相似文献
993.
994.
Leonardo Meneghin Mendon?a Carla da Silva Machado Cristiane Cardoso Correia Teixeira Luis Alexandre Pedro de Freitas Maria Lourdes Pires Bianchi Lusania Maria Greggi Antunes 《Genetics and molecular biology》2015,38(4):490-498
Curcumin (CMN) is the principal active component derived from the rhizome of
Curcuma longa (Curcuma longa L.). It is a
liposoluble polyphenolic compound that possesses great therapeutic potential. Its
clinical application is, however, limited by the low concentrations detected
following oral administration. One key strategy for improving the solubility and
bioavailability of poorly water-soluble drugs is solid dispersion, though it is not
known whether this technique might influence the pharmacological effects of CMN.
Thus, in this study, we aimed to evaluate the antioxidant and antigenotoxic effects
of CMN formulated in a solid dispersion (CMN SD) compared to unmodified CMN delivered
to Wistar rats. Cisplatin (cDDP) was used as the damage-inducing agent in these
evaluations. The comet assay results showed that CMN SD was not able to reduce the
formation of cDDP-DNA crosslinks, but it decreased the formation of micronuclei
induced by cDDP and attenuated cDDP-induced oxidative stress. Furthermore, at a dose
of 50 mg/kg b.w. both CMN SD and unmodified CMN increased the expression of
Tp53 mRNA. Our results showed that CMN SD did not alter the
antigenotoxic effects observed for unmodified CMN and showed effects similar to those
of unmodified CMN for all of the parameters evaluated. In conclusion, CMN SD
maintained the protective effects of unmodified CMN with the advantage of being
chemically water soluble, with maximization of absorption in the gastrointestinal
tract. Thus, the optimization of the physical and chemical properties of CMN SD may
increase the potential for the therapeutic use of curcumin. 相似文献
995.
Honit Piplani Stefanie Marek-Iannucci Jon Sin Jean Hou Toshimasa Takahashi Ankush Sharma Juliana de Freitas Germano Richard T. Waldron Hannaneh Saadaeijahromi Yang Song Aiste Gulla Bechien Wu Aurelia Lugea Allen M. Andres Herbert Y. Gaisano Roberta A. Gottlieb Stephen J. Pandol 《生物化学与生物物理学报:疾病的分子基础》2019,1865(11):165530
BackgroundDuring pancreatitis, autophagy is activated, but lysosomal degradation of dysfunctional organelles including mitochondria is impaired, resulting in acinar cell death. Retrospective cohort analyses demonstrated an association between simvastatin use and decreased acute pancreatitis incidence.MethodsWe examined whether simvastatin can protect cell death induced by cerulein and the mechanisms involved during acute pancreatitis. Mice were pretreated with DMSO or simvastatin (20 mg/kg) for 24 h followed by 7 hourly cerulein injections and sacrificed 1 h after last injection to harvest blood and tissue for analysis.ResultsPancreatic histopathology revealed that simvastatin reduced necrotic cell death, inflammatory cell infiltration and edema. We found that cerulein triggered mitophagy with autophagosome formation in acinar cells. However, autophagosome-lysosome fusion was impaired due to altered levels of LAMP-1, AMPK and ULK-1, resulting in autophagosome accumulation (incomplete autophagy). Simvastatin abrogated these effects by upregulating LAMP-1 and activating AMPK which phosphorylated ULK-1, resulting in increased formation of functional autolysosomes. In contrast, autophagosomes accumulated in control group during pancreatitis. The effects of simvastatin to promote autophagic flux were inhibited by chloroquine. Mitochondria from simvastatin-treated mice were resistant to calcium overload compared to control, suggesting that simvastatin induced mitochondrial quality control to eliminate susceptible mitochondria. Clinical specimens showed a significant increase in cell-free mtDNA in plasma during pancreatitis compared to normal controls. Furthermore, genetic deletion of parkin abrogated the benefits of simvastatin.ConclusionOur findings reveal the novel role of simvastatin in enhancing autophagic flux to prevent pancreatic cell injury and pancreatitis. 相似文献
996.
We give the chromosome numbers of about 80 species or subspecies of Biblidinae as well as of numbers of neotropical Libytheinae (one species), Cyrestinae (4) Apaturinae (7), Nymphalinae (about 40), Limenitidinae (16) and Heliconiinae (11). Libytheana has about n=32, the Biblidinae, Apaturinae and Nymphalinae have in general n=31, the Limenitidinae have n=30, the few Argynnini n=31 and the few species of Acraeni studied have also mostly n=31. The results agree with earlier data from the Afrotropical species of these taxa. We supplement these data with our earlier observations on Heliconiini, Danainae and the Neotropical Satyroid taxa. The lepidopteran modal n=29-31 represents clearly the ancestral condition among the Nymphalidae, from which taxa with various chromosome numbers have differentiated. The overall results show that Neotropical taxa have a tendency to evolve karyotype instability, which is in stark contrast to the otherwise stable chromosome numbers that characterize both Lepidoptera and Trichoptera. 相似文献
997.
Crystal structure of the Bowman-Birk Inhibitor from Vigna unguiculata seeds in complex with beta-trypsin at 1.55 A resolution and its structural properties in association with proteinases
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Barbosa JA Silva LP Teles RC Esteves GF Azevedo RB Ventura MM de Freitas SM 《Biophysical journal》2007,92(5):1638-1650
The structure of the Bowman-Birk inhibitor from Vigna unguiculata seeds (BTCI) in complex with β-trypsin was solved and refined at 1.55 Å to a crystallographic Rfactor of 0.154 and Rfree of 0.169, and represents the highest resolution for a Bowman-Birk inhibitor structure to date. The BTCI-trypsin interface is stabilized by hydrophobic contacts and hydrogen bonds, involving two waters and a polyethylene glycol molecule. The conformational rigidity of the reactive loop is characteristic of the specificity against trypsin, while hydrophobicity and conformational mobility of the antichymotryptic subdomain confer the self-association tendency, indicated by atomic force microscopy, of BTCI in complex and free form. When BTCI is in binary complexes, no significant differences in inhibition constants for producing a ternary complex with trypsin and chymotrypsin were detected. These results indicate that binary complexes present no conformational change in their reactive site for both enzymes confirming that these sites are structurally independent. The free chymotrypsin observed in the atomic force microscopy assays, when the ternary complex is obtained from BTCI-trypsin binary complex and chymotrypsin, could be related more to the self-association tendency between chymotrypsin molecules and the flexibility of the reactive site for this enzyme than to binding-related conformational changes. 相似文献
998.
999.
Julia M. I. Barth David Villegas‐Ríos Carla Freitas Even Moland Bastiaan Star Carl Andr Halvor Knutsen Ian Bradbury Jan Dierking Christoph Petereit David Righton Julian Metcalfe Kjetill S. Jakobsen Esben M. Olsen Sissel Jentoft 《Molecular ecology》2019,28(6):1394-1411
Genetic divergence among populations arises through natural selection or drift and is counteracted by connectivity and gene flow. In sympatric populations, isolating mechanisms are thus needed to limit the homogenizing effects of gene flow to allow for adaptation and speciation. Chromosomal inversions act as an important mechanism maintaining isolating barriers, yet their role in sympatric populations and divergence with gene flow is not entirely understood. Here, we revisit the question of whether inversions play a role in the divergence of connected populations of the marine fish Atlantic cod (Gadus morhua), by exploring a unique data set combining whole‐genome sequencing data and behavioural data obtained with acoustic telemetry. Within a confined fjord environment, we find three genetically differentiated Atlantic cod types belonging to the oceanic North Sea population, the western Baltic population and a local fjord‐type cod. Continuous behavioural tracking over 4 year revealed temporally stable sympatry of these types within the fjord. Despite overall weak genetic differentiation consistent with high levels of gene flow, we detected significant frequency shifts of three previously identified inversions, indicating an adaptive barrier to gene flow. In addition, behavioural data indicated that North Sea cod and individuals homozygous for the LG12 inversion had lower fitness in the fjord environment. However, North Sea and fjord‐type cod also occupy different depths, possibly contributing to prezygotic reproductive isolation and representing a behavioural barrier to gene flow. Our results provide the first insights into a complex interplay of genomic and behavioural isolating barriers in Atlantic cod and establish a new model system towards an understanding of the role of genomic structural variants in adaptation and diversification. 相似文献
1000.
Ricardo León-Sampedro Rosa del Campo Mercedes Rodriguez-Baños Val F. Lanza María José Pozuelo Carlos Francés-Cuesta Ana P. Tedim Ana R. Freitas Carla Novais Luísa Peixe Rob J. L. Willems Jukka Corander Fernando González Candelas Fernando Baquero Teresa M. Coque 《Environmental microbiology》2019,21(8):3046-3062
Wild birds have been suggested to be reservoirs of antimicrobial resistant and/or pathogenic Enterococcus faecalis (Efs) strains, but the scarcity of studies and available sequences limit our understanding of the population structure of the species in these hosts. Here, we analysed the clonal and plasmid diversity of 97 Efs isolates from wild migratory birds. We found a high diversity, with most sequence types (STs) being firstly described here, while others were found in other hosts including some predominant in poultry. We found that pheromone-responsive plasmids predominate in wild bird Efs while 35% of the isolates entirely lack plasmids. Then, to better understand the ecology of the species, the whole genome of fivestrains with known STs (ST82, ST170, ST16 and ST55) were sequenced and compared with all the Efs genomes available in public databases. Using several methods to analyse core and accessory genomes (AccNET, PLACNET, hierBAPS and PANINI), we detected differences in the accessory genome of some lineages (e.g. ST82) demonstrating specific associations with birds. Conversely, the genomes of other Efs lineages exhibited divergence in core and accessory genomes, reflecting different adaptive trajectories in various hosts. This pangenome divergence, horizontal gene transfer events and occasional epidemic peaks could explain the population structure of the species. 相似文献