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101.
Dendritic cells (DC) have important functions in T cell immunity and T cell tolerance. Previously, it was believed that T cell unresponsiveness induced by immature DC (iDC) is caused by the absence of inflammatory signals in steady-state in vivo conditions and by the low expression levels of costimulatory molecules on iDC. However, a growing body of evidence now indicates that iDC can also actively maintain peripheral T cell tolerance by the induction and/or stimulation of regulatory T cell populations. In this study, we investigated the in vitro T cell stimulatory capacity of iDC and mature DC (mDC) and found that both DC types induced a significant increase in the number of transforming growth factor (TGF)-beta and interleukin (IL)-10 double-positive CD4(+) T cells within 1 week of autologous DC/T cell co-cultures. In iDC/T cell cultures, where antigen-specific T cell priming was significantly reduced as compared to mDC/T cell cultures, we demonstrated that the tolerogenic effect of iDC was mediated by soluble TGF-beta and IL-10 secreted by CD4(+)CD25(-)FOXP3(-) T cells. In addition, the suppressive capacity of CD4(+) T cells conditioned by iDC was transferable to already primed antigen-specific CD8(+) T cell cultures. In contrast, addition of CD4(+) T cells conditioned by mDC to primed antigen-specific CD8(+) T cells resulted in enhanced CD8(+) T cell responses, notwithstanding the presence of TGF-beta(+)/IL-10(+) T cells in the transferred fraction. In summary, we hypothesize that DC have an active role in inducing immunosuppressive cytokine-secreting regulatory T cells. We show that iDC-conditioned CD4(+) T cells are globally immunosuppressive, while mDC induce globally immunostimulatory CD4(+) T cells. Furthermore, TGF-beta(+)/IL-10(+) T cells are expanded by DC independent of their maturation status, but their suppressive function is dependent on immaturity of DC.  相似文献   
102.
103.
Host-microorganism interactions in the intestinal tract are complex, and little is known about specific nonpathogenic microbial factors triggering host responses in the gut. In this study, mannose-specific interactions of Lactobacillus plantarum 299v with jejunal epithelium were investigated using an in situ pig Small Intestinal Segment Perfusion model. The effects of L. plantarum 299v wild-type strain were compared with those of two corresponding mutant strains either lacking the gene encoding for the mannose-specific adhesin (msa) or sortase (srtA; responsible for anchoring of cell surface proteins like Msa to the cell wall). A slight enrichment of the wild-type strain associated with the intestinal surface could be observed after 8 h of perfusion when a mixture of wild-type and msa-mutant strain had been applied. In contrast to the mutant strains, the L. plantarum wild-type strain tended to induce a decrease in jejunal net fluid absorption compared with control conditions. Furthermore, after 8 h of perfusion expression of the host gene encoding pancreatitis-associated protein, a protein with proposed bactericidal properties, was found to be upregulated by the wild-type strain only. These observations suggest a role of Msa in the induction of host responses in the pig intestine.  相似文献   
104.
105.
Interventional cardiology is an expanding field within cardiovascular medicine and today it is generally accepted that cardiologists require specific training, knowledge and skills. Hospitals where coronary interventions are performed must be properly equipped and able to provide specialised care. Percutaneous coronary interventions are frequently used for coronary revascularisation. The public should have confidence in the uniformity of high quality care. Therefore, such quality of care should be maintained by certification of the individual operators, general guidelines for institutional requirements and formal audits. The Netherlands Society of Cardiology (NVVC) will be implementing a new registration system for cardiologists with a subspecialisation that will include registration for interventional cardiology. The NVVC asked the Working Group of Interventional Cardiology (WIC) to update the 1994 Dutch guidelines on operator and institutional competence, and requirements for training in interventional cardiology in order to incorporate them into the official directives. The present guidelines represent the expert opinion of the Dutch interventional cardiology community and are in accordance with international regulations.After two rounds of discussion, the NVVC approved the guidelines in November 2004 during the autumn meeting.  相似文献   
106.
The infectivity of infective juveniles(IJs) of Heterorhabditis megidis (strain NLH-E87.3) produced on small, medium and large larvae ofGalleria mellonella, and on medium and largelarvae of Otiorhynchus sulcatus was tested underlaboratory conditions against G. mellonella andO. sulcatus larvae. Infective juvenilesoriginating from small G. mellonella exposed toan initial dose of one IJ were more infectious thanthose from small cadavers exposed to a dose of 30 IJs.Independent of the initial inoculum size, IJs fromsmall cadavers of G. mellonella were moreinfectious than those from medium and large cadavers.At a dose of one IJ per larva, IJs originating frommedium size O. sulcatus cadavers were moreinfective against G. mellonella than againstO. sulcatus larvae. Large G. mellonellalarvae were less susceptible to all IJ batches thanmedium and small sized larvae.  相似文献   
107.
108.
Ageing of gelatinised and partly gelatinised potato starch and wheat starch were investigated in the presence of plasticisers with increasing size and number of OH groups (ethylene glycol, glycerol, threitol, xylitol, glucose, and for potato starch also maltose). The influences of these plasticisers and of granular remnants (ghosts) on recrystallisation were determined by using X-ray diffraction. Recrystallisation of potato starch samples in the presence of plasticisers resulted in crystallinity indices of 0.5. The largest reduction in potato starch recrystallisation is found for threitol (4 OH) and xylitol (5 OH). In the plasticiser range examined, the crystallisation inducing effect of granular potato starch remnants is reduced better when the plasticiser contains more OH groups. Wheat starch recrystallises to a lesser extent than potato starch, resulting in crystallinity indices of 0.4. The results for wheat starch do not show clear trends for the influences of plasticiser size and of ghosts. The difference in behaviour of the two starches is probably caused by wheat starch having shorter amylopectin chains. Resulting from these shorter amylopectin chains, the remaining structure in wheat starch ghosts may resemble A-type crystallinity, making it more difficult to form B-type crystals. Alternatively, the trends as found for potato starch may occur, but are less manifest for wheat starch, due to the lower total extent of recrystallisation. Solid state CP/MAS NMR spectra of the wheat starch samples containing ethylene glycol were obtained, in order to compare completely and partly gelatinised systems. The spectra were identical, confirming that the ghost structures do not influence wheat starch recrystallisation. Apparently, wheat starch ghosts do not act as nuclei for crystallisation.

Similarly, the influence of various malto-oligosaccharides in combination with granular remnants (ghosts) was investigated on wheat starch ageing. Gelatinised and partly gelatinised wheat starch were plasticised with maltose, maltotriose, maltotetraose, maltopentaose or maltohexaose. This resulted in crystallinity indices of 0.2, with the largest reduction in recrystallisation for maltotriose and maltotetraose. No trend was found for the influence of ghosts. The presence of ghosts did not influence the 13C solid state HP/DEC NMR spectra. Less recrystallisation took place than with the previously mentioned smaller plasticisers that resulted in crystallinity indices of 0.4. The finding that maltose was able to reduce retrogradation better than glucose could be of practical importance.  相似文献   

109.
Abstract. Within the framework of the Dutch ‘Network Ecological Monitoring’, a large set of new permanent plots has been established to monitor selected plant communities throughout The Netherlands for studying the effects of environmental changes on species composition of semi‐natural communities. This national programme will also make use of pre‐existing permanent plots. These plots reflect the long and comprehensive history of research using permanent plots in The Netherlands, where the first permanent plots were established in the early 1930s. To enhance the usefulness of preexisting permanent plots, a comprehensive permanent plot database was compiled. This database was derived from the Dutch National Vegetation Database, that was established for the recent vegetation classification of The Netherlands. This was supplemented with information from various organizations and a number of individual researchers. Currently, the permanent plot database contains ca. 6000 permanent plots. More than 2500 of these plots have been sampled at least 5, and ca. 1500 plots at least 10. Most of the plots are from grasslands, followed by forests and dune systems. This database not only provides insight into vegetation succession, fluctuations within plant communities over time, and the effects of changes of the environment on the vegetation but, indirectly, italso offers the possibility of studying the long‐term behaviour of individual plant species (e.g. establishment, competition, longevity). For the Network Ecological Monitoring a selection of these (historical) plots will be added to the new network of permanent plots in The Netherlands, thus supplying information of past vegetation conditions.  相似文献   
110.
We studied the host-finding and dispersion behaviour of Heterorhabditis megidis (strain NLHE 87.3) in the presence of Galleria mellonella or Otiorhynchus sulcatus larvae and strawberry roots. In large Petri dishes (19 cm diameter) filled with moist sand (8% w/w), and incubated at 15°C over 24 h, infective juveniles (IJs) responded positively to the presence of G. mellonella , to roots of a single strawberry plant and to O. sulcatus larvae in direct contact with roots of a single strawberry plant. A neutral or negative response was observed when IJs were presented with only O. sulcatus larvae or a combination of several strawberry plants with O. sulcatus larvae, either in contact or not in contact with the roots. IJs responded strongly to the combination of plant roots and feeding larvae indicating that the tritrophic interaction formed by IJs - O. sulcatus larvae - strawberry plants may be an infochemical-mediated interaction.  相似文献   
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