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931.
Dendritic cell type determines the mechanism of bystander suppression by adaptive T regulatory cells specific for the minor antigen HA-1 总被引:1,自引:0,他引:1
Derks RA Jankowska-Gan E Xu Q Burlingham WJ 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(6):3443-3451
One hallmark of acquired tolerance is bystander suppression, a process whereby Ag-specific (adaptive) T regulatory cells (TR) inhibit the T effector cell response both to specific Ag and to a colocalized third-party Ag. Using peripheral blood T cells from recipients of HLA-identical kidney transplants as responders in the trans vivo-delayed type hypersensitivity assay, we found that dendritic cells (DC), but not monocyte APCs, could mediate bystander suppression of EBV-specific recall response. When HA-1(H) peptide was added to mixtures of plasmacytoid DC (pDC) and T cells, bystander suppression of the response to a colocalized recall Ag occurred primarily via indolamine-2,3-dioxygenase (IDO) production. Similarly, addition of HA-1(H) peptide to cocultures of T cells and pDC, but not myeloid DC (mDC), induced IDO activity in vitro. When mDC presented HA-1(H) peptide to Ag-specific CD8+ TR, cytokine release (TGF-beta, IL-10, or both) was the primary mode of bystander suppression. Bystander suppression via mDC was reversed not only by Ab to TGF-beta and its receptor on T cells, but also by Ab to thrombospondin-1. EBV addition did not induce IDO or thrombospondin-1 in T-DC cocultures, suggesting that these DC products are not induced by T effector cells, but only by TR cells. These results shed light upon the mechanism of bystander suppression by donor Ag-specific TR in patients with organ transplant tolerance and underscores the distinct and critical roles of mDC and pDCs in this phenomenon. 相似文献
932.
Augustynowicz E Szenborn L Gzyl A Slusarczyk J 《Medycyna do?wiadczalna i mikrobiologia》2007,59(2):103-112
Close contacts between children attending day-care centres, orphanages or similar institutions favours mutual transmission of infections with nontypeable H. influenzae (NTHi) strains. NTHi are transmitted via air-droplets or via direct contact with respiratory system exudates from nonsymptomatic carriers. The study aimed at monitoring of potentially invasive nontypeable H. influenzae strains of hmwA+ profile among children in day-care centres and orphanages. Monitoring of prevalence of strains of hmwA profile in a single day-care centres within 8 months confirmed high level of NTHi strains transmission including NTHi strains potentially invasive. It has been shown, that potentially invasive NTHi strains appear with different frequency in day-care centres and orphanages. It also points out that dissemination NTHi is easy in such an environment. 相似文献
933.
Gzyl A Augustynowicz E Zawadka M Rabczenko D Slusarczyk J 《Medycyna do?wiadczalna i mikrobiologia》2007,59(2):123-135
The study is based on assumption that B. pertussis strains harbouring different allele variants of genes encoding subunit S1 of pertussis toxin and pertactin might be eliminated with different efficiency from lung tissue of mice which were immunized with whole-cell and acellular pertussis vaccines. It has been assumed that strains containing combinations of genes alleles which were not prevalent since 1990-ties are consisting of mutated strains in respect to pertussis toxin subunit S1 and pertactin, and are capable to decrease efficiency of pertussis vaccines. Experiments performed in vivo dealt with activity of tested vaccines against B. pertussis strains of different combinations of ptxS1/prn. The study indicated for lowered efficiency of whole-cell and acellular pertussis vaccines in elimination of mutated strains of B. pertussis from animal lung tissue in comparison with strains currently used for vaccine production. 相似文献
934.
Ewa Sobieszczuk-Nowicka Alessia Di Sandro Stefano Del Duca Donatella Serafini-Fracassini Jolanta Legocka 《Physiologia plantarum》2007,130(4):590-600
The amounts of polyamines (PAs) bound to etioplast membranes varied during chloroplast development in cucumber cotyledons ( Cucumis sativus L. cv. Racibór). Putrescine (PU) and spermidine (SD) levels increased in the early greening stage (6 h of light exposure) but decreased in the late greening stage (24 h) in the thylakoid-enriched fraction. In the highly enriched PSIIα fraction, the trend of changes in the amount of bound PAs was different: levels of SD and spermine (SM) increased in the late stage. In both fractions, their levels were additionally increased by kinetin treatment. In the presence of exogenous protein transglutaminase (TGase) substrate ( N ', N '-dimethylcasein) and 5 m M Ca2+ , kinetin initially caused a marked increase in thylakoid transglutaminase (ThylTGase) activity (6 h), followed by a decrease at the end of greening. The radiometric assay showed that PU and SM binding to thylakoid proteins was very low, while SD binding was seven to eight times higher. Kinetin increased SD conjugation in the early greening stage by about 36%. When chloroplast membranes were fully organized, ThylTGase activity decreased. In etioplast membranes and during the early greening stage, the 77-kDa and 30-kDa bands were mainly immunodetected with antibodies raised against the animal TGase, which were in general slightly stronger for kinetin-treated than the control samples. At the end of greening, the level of 77-kDa ThylTGase dramatically decreased. ThylTGase activity was found to be Ca2+ dependent. PAs conjugated via ThylTGase, in addition to the PAs bound by all possible types of linkage, could represent an important component of the mechanism of stimulation of etioplast-to-chloroplast transformation by kinetin. 相似文献
935.
936.
Prion protein gene (PRNP) variants determine the susceptibility of humans, sheep and mice to prion diseases, whereas polymorphisms in the open reading frame (ORF) of bovine PRNP seem to be unrelated to the incidence of bovine spongiform encephalopathy (BSE). According to the latest reports, the genetic susceptibility of cattle to BSE is associated with polymorphisms ofthe regulatory region of the PRNP gene and the level ofits expression. This review provides information on the bovine PRNP gene, its polymorphism, and recently identified genetic markers for BSE, and attempts to explain the mechanism behind the genetic resistance or susceptibility of cattle to this disease. 相似文献
937.
The karyotype of the Italian goose originating from Anser anser was characterised on the basis of R and C bands. Chromosomal preparations obtained from an in vitro culture of blood lymphocytes were stained with the RBG and CBG techniques. The RBG technique enabled the analysis of the structure of nine pairs of chromosomes whereas the CBG technique - fourteen pairs ofchromosomes from the total ofeighty goose chromosomes. The morphology and the R and C banding patterns were described. The size and arrangement of the blocks of constitutive chromatin were determined. Ideograms of R and C banded patterns were drawn. The morphological structure of the analysed chromosomes was evaluated. 相似文献
938.
The presence of Paramecium sexaurelia from the Paramecium aurelia complex was recorded for the first time in China (Beijing). RAPD fingerprints (band patterns) of P. sexaurelia strains, the new strain from China and others from Asia, as well as from Europe and Puerto Rico, showed polymorphism within the species as several groups of genotypes characterized by different band patterns. 相似文献
939.
The presence of Paramecium decaurelia from the Paramecium aurelia species complex was demonstrated in Yaroslavl, Russia, (European part, northwestern Russia) and in the Altai Mts (Asiatic part of Russia, western Siberia). RAPD-PCR fingerprints of the newly identified strains of P. decaurelia, rare throughout the world, were compared to those characteristic for the other known strains ofthe species. P. decaurelia strains show some polymorphism within species, strains from Russia have 60% similarity of band patterns, and strains from USA and Japan about 70% similarity of band patterns. 相似文献
940.
Deschner J Rath-Deschner B Wypasek E Anghelina M Sjostrom D Agarwal S 《Journal of biomechanics》2007,40(7):1541-1549
We sought to examine whether cyclic tensile strain (CTS) regulates the gene expression of tumor necrosis factor (TNF)-alpha, its receptors TNFR1 and TNFR2, and inducible nitric oxide synthase (iNOS) under inflammatory conditions, and whether these effects of CTS are sustained. Rat temporomandibular joint disc cells (TDC) were exposed to CTS in the presence or absence of interleukin (IL)-1beta for 4 and 24h. Cells were also stimulated with IL-1beta for 24h while being subjected to CTS only for the initial 1, 2, 4, 8, and 12h or the entire 24h incubation time. Furthermore, cells were incubated with IL-1beta for 24, 36, or 48 h while being exposed to CTS only for the initial 8h. Gene expression of TNF-alpha, its receptors, and iNOS was analyzed by RT-PCR, whereas protein synthesis was determined by ELISA for TNF-alpha, immunofluorescence for TNFRs, and Griess reaction for nitric oxide. CTS inhibited the IL-1beta-stimulated synthesis of TNF-alpha, TNFR2, and iNOS. TNFR1 was constitutively expressed but not regulated by IL-1beta or CTS. Application of CTS for only 1 or 2h during a 24h incubation with IL-1beta was sufficient to inhibit IL-1beta-induced upregulation of TNF-alpha, TNFR2, and iNOS. However, for maximal inhibition of these genes a longer exposure of CTS was required. These findings are the first to show that biomechanical signals regulate the expression of TNFR2 but not TNFR1 under inflammatory conditions. Furthermore, the antiinflammatory effects of biomechanical signals on TDC are maintained for prolonged periods of time but are transient. 相似文献