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941.
This work aims to study the influence of H-2 locus in the control of Leishmania infantum infection by evaluating whether cytokine responses by host macrophages of different H-2 haplotype are differentially regulated, either induced or actively impaired during parasite growth and replication. This study shows that macrophages of "non-cure" phenotype (H-2(d)) are more susceptible to infection with virulent L. infantum promastigotes. Virulent parasites lead to impaired IL-12 and inhibited TNF-alpha expression. The degree of parasite virulence is an important contributing factor to differences detected in cytokine expression. Virulent parasites also induced TGF-beta, a deactivating cytokine that is known to suppress Th-1 type responses, thus allowing the parasite to subvert antimicrobial activity and increase its chances of survival. Depending on specific host haplotype, cells differentially respond to infection since TNF-alpha expression is inhibited and TGF-beta is enhanced by macrophages of "non-cure" phenotype, thus perhaps determining their degree of susceptibility in this strain of mice. 相似文献
942.
Guimarães RJ Freitas CC Dutra LV Moura AC Amaral RS Drummond SC Guerra M Scholte RG Freitas CR Carvalho OS 《Memórias do Instituto Oswaldo Cruz》2006,101(Z1):91-96
The aim of this work is to establish a relationship between schistosomiasis prevalence and social-environmental variables, in the state of Minas Gerais, Brazil, through multiple linear regression. The final regression model was established, after a variables selection phase, with a set of spatial variables which contains the summer minimum temperature, human development index, and vegetation type variables. Based on this model, a schistosomiasis risk map was built for Minas Gerais. 相似文献
943.
NOX2 controls phagosomal pH to regulate antigen processing during crosspresentation by dendritic cells 总被引:16,自引:0,他引:16
Savina A Jancic C Hugues S Guermonprez P Vargas P Moura IC Lennon-Duménil AM Seabra MC Raposo G Amigorena S 《Cell》2006,126(1):205-218
To initiate adaptative cytotoxic immune responses, proteolytic peptides derived from phagocytosed antigens are presented by dendritic cells (DCs) to CD8+ T lymphocytes through a process called antigen "crosspresentation." The partial degradation of antigens mediated by lysosomal proteases in an acidic environment must be tightly controlled to prevent destruction of potential peptides for T cell recognition. We now describe a specialization of the phagocytic pathway of DCs that allows a fine control of antigen processing. The NADPH oxidase NOX2 is recruited to the DC's early phagosomes and mediates the sustained production of low levels of reactive oxygen species, causing active and maintained alkalinization of the phagosomal lumen. DCs lacking NOX2 show enhanced phagosomal acidification and increased antigen degradation, resulting in impaired crosspresentation. Therefore, NOX2 plays a critical role in conferring DCs the ability to function as specialized phagocytes adapted to process antigens rather than kill pathogens. 相似文献
944.
Sillankorva S Oliveira D Moura A Henriques M Faustino A Nicolau A Azeredo J 《Current microbiology》2011,62(4):1128-1132
Persistent urinary tract infections (UTI) are often caused by E. coli adhered to urothelium. This type of cells is generally recognized as very tolerant to antibiotics which renders difficult
the treatment of chronic UTI. This study investigates the use of lytic bacteriophages as alternative antimicrobial agents,
particularly the interaction of phages with E. coli adhered to urothelium and specifically determines their efficiency against this type of cells. The bacterial adhesion to
urothelium was performed varying the bacterial cell concentrations and the period and conditions (static, shaken) of adhesion.
Three collection bacteriophages (T1, T4, and phiX174 like phages) were tested against clinical E. coli isolates and only one was selected for further infection experiments. Based on the lytic spectrum against clinical isolates
and its ability to infect the highest number of antibiotic resistant strains, the T1-like bacteriophage was selected. This
bacteriophage caused nearly a 45% reduction of the bacterial population after 2 h of treatment. This study provides evidence
that bacteriophages are effective in controlling suspended and adhered cells and therefore can be a viable alternative to
antibiotics to control urothelium- adhered bacteria. 相似文献
945.
South‐western Atlantic reef fishes: Zoogeographical patterns and ecological drivers reveal a secondary biodiversity centre in the Atlantic Ocean 下载免费PDF全文
Hudson T. Pinheiro Luiz A. Rocha Raphael M. Macieira Alfredo Carvalho‐Filho Antônio B. Anderson Mariana G. Bender Fabio Di Dario Carlos Eduardo L. Ferreira Jessé Figueiredo‐Filho Ronaldo Francini‐Filho João L. Gasparini Jean‐Christophe Joyeux Osmar J. Luiz Michael M. Mincarone Rodrigo L. Moura José de Anchieta C. C. Nunes Juan P. Quimbayo Ricardo S. Rosa Cláudio L. S. Sampaio Ivan Sazima Daniele A. Vila‐Nova Sergio R. Floeter 《Diversity & distributions》2018,24(7):951-965
946.
947.
Gaspari Stefania Scheinin Aviad Holcer Draško Fortuna Caterina Natali Chiara Genov Tilen Frantzis Alexandros Chelazzi Guido Moura André E. 《Evolutionary biology》2015,42(2):177-190
Evolutionary Biology - The drivers of population differentiation in oceanic high dispersal organisms, have been crucial for research in evolutionary biology. Adaptation to different environments is... 相似文献
948.
Increased steroidogenic factor-1 dosage triggers adrenocortical cell proliferation and cancer 总被引:1,自引:0,他引:1
949.
ATP prevents G-actin cysteine oxidation and vanadyl formation specifically induced by decavanadate, suggesting that the oxometalate-protein interaction is affected by the nucleotide. The ATP exchange rate is increased by 2-fold due to the presence of decavanadate when compared with control actin (3.1 × 10− 3 s− 1), and an apparent dissociation constant (kdapp) of 227.4 ± 25.7 μM and 112.3 ± 8.7 μM was obtained in absence or presence of 20 μM V10, respectively. Moreover, concentrations as low as 50 μM of decameric vanadate species (V10) increases the relative G-actin intrinsic fluorescence intensity by approximately 80% whereas for a 10-fold concentration of monomeric vanadate (V1) no effects were observed. Upon decavanadate titration, it was observed a linear increase in G-actin hydrophobic surface (2.6-fold), while no changes were detected for V1 (0-200 μM). Taken together, three major ideas arise: i) ATP prevents decavanadate-induced G-actin cysteine oxidation and vanadate reduction; ii) decavanadate promotes actin conformational changes resulting on its inactivation, iii) decavanadate has an effect on actin ATP binding site. Once it is demonstrated that actin is a new potential target for decavanadate, being the ATP binding site a suitable site for decavanadate binding, it is proposed that some of the biological effects of vanadate can be, at least in part, explained by decavanadate interactions with actin. 相似文献
950.