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排序方式: 共有832条查询结果,搜索用时 207 毫秒
61.
Viral replication capacity as a correlate of HLA B57/B5801-associated nonprogressive HIV-1 infection 总被引:6,自引:0,他引:6
Navis M Schellens I van Baarle D Borghans J van Swieten P Miedema F Kootstra N Schuitemaker H 《Journal of immunology (Baltimore, Md. : 1950)》2007,179(5):3133-3143
HLA B57 and the closely related HLA B5801 are over-represented among HIV-1 infected long-term nonprogressors (LTNPs). It has been suggested that this association between HLA B57/5801 and asymptomatic survival is a consequence of strong CTL responses against epitopes in the viral Gag protein. Moreover, CTL escape mutations in Gag would coincide with viral attenuation, resulting in low viral load despite evasion from immune control. In this study we compared HLA B57/5801 HIV-1 infected progressors and LTNPs for sequence variation in four dominant epitopes in Gag and their ability to generate CTL responses against these epitopes and the autologous escape variants. Prevalence and appearance of escape mutations in Gag epitopes and potential compensatory mutations were similar in HLA B57/5801 LTNPs and progressors. Both groups were also indistinguishable in the magnitude of CD8+ IFN-gamma responses directed against the wild-type or autologous escape mutant Gag epitopes in IFN-gamma ELISPOT analysis. Interestingly, HIV-1 variants from HLA B57/5801 LTNPs had much lower replication capacity than the viruses from HLA B57/5801 progressors, which did not correlate with specific mutations in Gag. In conclusion, the different clinical course of HLA B57/5801 LTNPs and progressors was not associated with differences in CTL escape mutations or CTL activity against epitopes in Gag but rather with differences in HIV-1 replication capacity. 相似文献
62.
63.
Ganesan PL Alexander SI Watson D Logan GJ Zhang GY Alexander IE 《Cancer immunology, immunotherapy : CII》2007,56(12):1955-1965
Successful immunotherapy of solid tumors has proven difficult to achieve. The aim of the current study was to further investigate
the effects of peripheral CD80-mediated co-stimulation on the efficacy of polyclonal anti-tumor effector CTL in an adoptive
transfer model. Splenocytes obtained from wild-type mice immunized with CD80-transduced EL4 tumor cells were expanded in vitro
in the presence of either IL-12 or IL-15 and irradiated CD80-transduced EL4 tumor cells. Polyclonal CD8 T cells were the major
subset in the effector population. Primed effector cells were adoptively transferred into immuno-deficient Rag-1-deficient
mice which were then challenged with syngeneic vector-control or CD80-transduced EL4 tumor cells. Expression of CD80 enhanced
the elimination of EL4 tumors and mouse survival. Both IL-12 and IL-15 cultured cells had enhanced cytotoxicity. Importantly,
anti-tumor memory was maintained without tumor evasion following re-challenge with either CD80-transduced and vector-control
EL4 cells. We also show, using antibody-mediated depletion, that endogenous NK cells present in Rag-1-deficent mice exert
anti-EL4 tumor activity that is enhanced by CD80 expression. Collectively these data show that peripheral co-stimulation by
tumor expression of CD80 results in enhanced anti-tumor efficacy of NK and polyclonal effector T cells, and suggest that TCR
repertoire diversity helps protect against tumor escape and provides memory with resultant robust immunity to subsequent tumor
challenge irrespective of CD80 status. 相似文献
64.
Singla DK McDonald DE 《American journal of physiology. Heart and circulatory physiology》2007,293(3):H1590-H1595
Our recent study (Singla DK, Hacker TA, Ma L, Douglas PS, Sullivan R, Lyons GE, Kamp TJ, J Mol Cell Cardiol 40: 195-200, 2006) suggests that transplanted embryonic stem (ES) cells subsequent to myocardial infarction differentiate into the major cell types in the heart and improve cardiac function. However, the extent of regeneration is relatively meager compared with the observed functional improvement. The mechanisms underlying their improved function are completely unknown. In this report, we provide evidence using a cell culture model system for novel mechanisms that involve the release of cytoprotective, anti-apoptotic factor(s) from ES cells and inhibit H(2)O(2)-induced apoptosis in the rat cardiomyocyte-derived cell line H9c2. Conditioned medium (CM) from growing mouse ES cells treated with and without H(2)O(2) was generated. Apoptosis was induced after exposure to H(2)O(2) in H9c2 cells for 2 h followed by replacement with fresh cell culture or ES cell-CM. After 24 h, H9c2 cells treated with both ES cell-CMs demonstrated significantly decreased apoptosis, as determined by terminal deoxynucleotidyl transferase dUTP-mediated nick-end labeling staining, apoptotic ELISA, caspase-3 activity, and DNA ladder. Next, using Luminex technology, we examined the presence of antiapoptotic proteins cystatin c, osteopontin, and clusterin and anti-fibrotic, tissue inhibitor of metalloproteinase-1 (TIMP-1) in both ES cell-CMs. The levels of released factors were 2- to 170-fold higher than those in H9c2 cell-CM. Antiapoptotic effects of ES cell-CM were significantly inhibited with TIMP-1 antibody, suggesting that TIMP-1 is an important factor to inhibit apoptosis. Furthermore, we used CM from an TIMP-1-overexpressing cell line and demonstrated that H(2)O(2)-induced apoptosis in the H9c2 cells was significantly inhibited. These observations demonstrate that factors released from ES cells contain antiapoptotic factors and that the effects are mediated by TIMP-1. Moreover, these findings suggest that released factors might be useful for therapeutic applications in ischemic heart disease as well as for many other diseases. 相似文献
65.
Long-term storage of DNA-free RNA for use in vaccine studies 总被引:2,自引:0,他引:2
RNA replicons represent potential vaccine delivery vehicles, but are considered too unstable for such use. This study examined the recovery, integrity and function of in vitro transcribed replicon RNA encoding hepatitis C virus (HCV) proteins. To remove residual template DNA, the RNA was digested with TURBO DNase followed by RNeasy DNase set and purified through an RNeasy column. The RNA was freeze-dried in distilled water or trehalose, stored under nitrogen gas for up to 10 months and analyzed at different time points. The recovery of RNA stored at < or = 4 degrees C that was freeze-dried in distilled water varied between 66% to zero of that recovered from RNA freeze-dried in 10% trehalose, a figure that depended on the duration of storage. In contrast, the recovery of the RNA stored in trehalose was consistently high for all time points. After recovery, both RNAs were translationally competent and expressed high levels of proteins after transfection, although the level of expression from the trehalose-stored RNA was consistently higher. Thus the addition of trehalose permitted stable storage of functional RNA at 4 degrees C for up to 10 months and this permits the development of RNA vaccines, even in developing countries where only minimum storage conditions (e.g., 4 degrees C) can be achieved. 相似文献
66.
67.
Gealy EC Kerr BC Young RD Tudor D Hayes AJ Hughes CE Caterson B Quantock AJ Ralphs JR 《Histochemistry and cell biology》2007,128(6):551-555
Keratan sulphate (KS) proteoglycans (PGs) are key molecules in the connective tissue matrix of the cornea of the eye, where
they are believed to have functional roles in tissue organisation and transparency. Keratocan, is one of the three KS PGs
expressed in cornea, and is the only one that is primarily cornea-specific. Work with the developing chick has shown that
mRNA for keratocan is present in early corneal embryogenesis, but there is no evidence of protein synthesis and matrix deposition.
Here, we investigate the tissue distribution of keratocan in the developing chick cornea as it becomes compacted and transparent
in the later stages of development. Indirect immunofluorescence using a new monoclonal antibody (KER-1) which recognises a
protein epitope on the keratocan core protein demonstrated that keratocan was present at all stages investigated (E10–E18),
with distinct differences in localisation and organisation observed between early and later stages. Until E13, keratocan appeared
both cell-associated and in the stromal extracellular matrix, and was particularly concentrated in superficial tissue regions.
By E14 when the cornea begins to become transparent, keratocan was located in elongate arrays, presumably associated along
collagen fibrils in the stroma. This fibrillar label was still concentrated in the anterior stroma, and persisted through
E15–E18. Presumptive Bowman’s layer was evident as an unlabelled subepithelial zone at all stages. Thus, in embryonic chick
cornea, keratocan, in common with sulphated KS chains in the E12–E14 developmental period, exhibits a preferential distribution
in the anterior stroma. It undergoes a striking reorganisation of structure and distribution consistent with a role in relation
to stromal compaction and corneal transparency.
E. Claire Gealy and Briedgeen C. Kerr were joint first authors. 相似文献
68.
Cristiano S. Moura Michal Abrahamowicz Marie-Eve Beauchamp Diane Lacaille Yishu Wang Gilles Boire Paul R. Fortin Louis Bessette Claire Bombardier Jessica Widdifield John G. Hanly Debbie Feldman Walter Maksymowych Christine Peschken Cheryl Barnabe Steve Edworthy Sasha Bernatsky CAN-AIM 《Arthritis research & therapy》2015,17(1)
IntroductionUse of disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA) may prevent joint damage and potentially reduce joint replacement surgeries. We assessed the association between RA drug use and joint replacement in Quebec, Canada.MethodsA cohort of new-onset RA patients was identified from Quebec’s physician billing and hospitalization databases from 2002–2011. The outcome was defined using procedure codes submitted by orthopedic surgeons. Medication use was obtained from pharmacy databases. We used alternative Cox regression models with time-dependent variables measuring the cumulative effects of past use during different time windows (one model focussing on the first year after cohort entry) for methotrexate (MTX), and other DMARDs. Models were adjusted for baseline sociodemographics, co-morbidity and prior health service use, time-dependent cumulative use of other drugs (anti-tumor necrosis factor [anti-TNF] agents, other biologics, cyclooxygenase-2 inhibitors [COXIBs], nonselective nonsteroidal antiinflammatory drugs [NSAIDs], and systemic steroids), and markers of disease severity.ResultsDuring follow-up, 608 joint replacements occurred among 11,333 patients (median follow-up: 4.6 years). The best-fitting model relied on the cumulative early use (within the first year after cohort entry) of MTX and of other DMARDs, with an interaction between MTX and other DMARDs. In this model, greater exposure within the first year, to either MTX (adjusted hazard ratio, HR = 0.95 per 1 month, 95 % confidence interval, 95 % CI 0.93-0.97) or other DMARDs (HR = 0.97, 95 % CI 0.95-0.99) was associated with longer time to joint replacement.ConclusionsOur results suggest that longer exposure to either methotrexate (MTX) or other DMARDs within the first year after RA diagnosis is associated with longer time to joint replacement surgery.
Electronic supplementary material
The online version of this article (doi:10.1186/s13075-015-0713-3) contains supplementary material, which is available to authorized users. 相似文献69.
Debbie C. Crans Samantha Schoeberl Ernestas Gaidamauskas Bharat Baruah Deborah A. Roess 《Journal of biological inorganic chemistry》2011,16(6):961-972
The interactions of metabolites of the antidiabetic vanadium-containing drug bis(maltolato)oxovanadium(IV) (BMOV) with lipid
interface model systems were investigated and the results were used to describe a potentially novel mechanism by which these
compounds initiate membrane-receptor-mediated signal transduction. Specifically, spectroscopic studies probed the BMOV oxidation
and hydrolysis product interaction with interfaces created from cetyltrimethylammonium bromide (CTAB) which mimics the positively
charged head group on phosphatidylcholine. 1H and 51V NMR spectroscopies were used to determine the location of the dioxobis(maltolato)oxovanadate(V) and the maltol ligand in
micelles and reverse micelles by measuring changes in the chemical shift, signal linewidth, and species distribution. Both
micelles and reverse micelles interacted similarly with the complex and the ligand, suggesting that interaction is strong
as anticipated by Coulombic attraction between the positively charged lipid head group and the negatively charged complex
and deprotonated ligand. The nature of the model system was confirmed using dynamic light scattering studies and conductivity
measurements. Interactions of the complex/ligand above and below the critical micelle concentration of micelle formation were
different, with much stronger interactions when CTAB was in the form of a micelle. Both the complex and the ligand penetrated
the lipid interface and were located near the charged head group. These studies demonstrate that a lipid-like interface affects
the stability of the complex and raise the possibility that ligand exchange at the interface may be important for the mode
of action for these systems. Combined, these studies support recently reported in vivo observations of BMOV penetration into
3T3-L1 adipocyte membranes and increased translocation of a glucose transporter to the plasma membrane. 相似文献
70.
Cheeseman MT Tyrer HE Williams D Hough TA Pathak P Romero MR Hilton H Bali S Parker A Vizor L Purnell T Vowell K Wells S Bhutta MF Potter PK Brown SD 《PLoS genetics》2011,7(10):e1002336
Otitis media with effusion (OME) is the commonest cause of hearing loss in children, yet the underlying genetic pathways and mechanisms involved are incompletely understood. Ventilation of the middle ear with tympanostomy tubes is the commonest surgical procedure in children and the best treatment for chronic OME, but the mechanism by which they work remains uncertain. As hypoxia is a common feature of inflamed microenvironments, moderation of hypoxia may be a significant contributory mechanism. We have investigated the occurrence of hypoxia and hypoxia-inducible factor (HIF) mediated responses in Junbo and Jeff mouse mutant models, which develop spontaneous chronic otitis media. We found that Jeff and Junbo mice labeled in vivo with pimonidazole showed cellular hypoxia in inflammatory cells in the bulla lumen, and in Junbo the middle ear mucosa was also hypoxic. The bulla fluid inflammatory cell numbers were greater and the upregulation of inflammatory gene networks were more pronounced in Junbo than Jeff. Hif-1α gene expression was elevated in bulla fluid inflammatory cells, and there was upregulation of its target genes including Vegfa in Junbo and Jeff. We therefore investigated the effects in Junbo of small-molecule inhibitors of VEGFR signaling (PTK787, SU-11248, and BAY 43-9006) and destabilizing HIF by inhibiting its chaperone HSP90 with 17-DMAG. We found that both classes of inhibitor significantly reduced hearing loss and the occurrence of bulla fluid and that VEGFR inhibitors moderated angiogenesis and lymphangiogenesis in the inflamed middle ear mucosa. The effectiveness of HSP90 and VEGFR signaling inhibitors in suppressing OM in the Junbo model implicates HIF-mediated VEGF as playing a pivotal role in OM pathogenesis. Our analysis of the Junbo and Jeff mutants highlights the role of hypoxia and HIF-mediated pathways, and we conclude that targeting molecules in HIF-VEGF signaling pathways has therapeutic potential in the treatment of chronic OM. 相似文献