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31.
Ankita Varshney Priyankar Sen Ejaz Ahmad Mohd. Rehan Naidu Subbarao Rizwan Hasan Khan 《Chirality》2010,22(1):77-87
Human serum albumin (HSA), being the most abundant carrier protein in blood and a modern day clinical tool for drug delivery, attracts high attention among biologists. Hence, its unfolding/refolding strategies and exogenous/endogenous ligand binding preference are of immense use in therapeutics and clinical biochemistry. Among its fellow proteins albumin is known to carry almost every small molecule. Thus, it is a potential contender for being a molecular cargo/or nanovehicle for clinical, biophysical and industrial purposes. Nonetheless, its structure and function are largely regulated by various chemical and physical factors to accommodate HSA to its functional purpose. This multifunctional protein also possesses enzymatic properties which may be used to convert prodrugs to active therapeutics. This review aims to highlight current overview on the binding strategies of protein to various ligands that may be expected to lead to significant clinical applications. Chirality, 2010. © 2009 Wiley‐Liss, Inc. 相似文献
32.
Modification to the capsid of the adenovirus vector that enhances dendritic cell infection and transgene-specific cellular immune responses 总被引:5,自引:0,他引:5 下载免费PDF全文
Worgall S Busch A Rivara M Bonnyay D Leopold PL Merritt R Hackett NR Rovelink PW Bruder JT Wickham TJ Kovesdi I Crystal RG 《Journal of virology》2004,78(5):2572-2580
Adenovirus (Ad) gene transfer vectors can be used to transfer and express antigens and function as strong adjuvants and thus are useful platforms for the development of genetic vaccines. Based on the hypothesis that Ad vectors with enhanced infectibility of dendritic cells (DC) may be able to evoke enhanced immune responses against antigens encoded by the vector in vivo, the present study analyzes the vaccine potential of an Ad vector expressing beta-galactosidase as a model antigen and genetically modified with RGD on the fiber knob [AdZ.F(RGD)] to more selectively infect DC and consequently enhance immunity against the beta-galactosidase antigen. Infection of murine DC in vitro with AdZ.F(RGD) showed an eightfold-increased transgene expression following infection compared to AdZ (also expressing beta-galactosidase, but with a wild-type capsid). Binding, cellular uptake, and trafficking in DC were also increased with AdZ.F(RGD) compared to AdZ. To determine whether AdZ.F(RGD) could evoke enhanced immune responses to beta-galactosidase in vivo, C57BL/6 mice were immunized with AdZ.F(RGD) or AdZ subcutaneously via the footpad. Humoral responses with both vectors were comparable, with similar anti-beta-galactosidase antibody levels following vector administration. However, cellular responses to beta-galactosidase were significantly enhanced, with the frequency of CD4(+) as well as the CD8(+) beta-galactosidase-specific gamma interferon response in cells isolated from the draining lymph nodes increased following immunization with AdZ.F(RGD) compared to Ad.Z (P < 0.01). Importantly, this enhanced cellular immune response of the AdZ.F(RGD) vector was sufficient to evoke enhanced inhibition of the growth of preexisting tumors expressing beta-galactosidase: BALB/c mice implanted with the CT26 syngeneic beta-galactosidase-expressing colon carcinoma cell line and subsequently immunized with AdZ.F(RGD) showed decreased tumor growth and improved survival compared to mice immunized with AdZ. These data demonstrate that addition of an RGD motif to the Ad fiber knob increases the infectibility of DC and leads to enhanced cellular immune responses to the Ad-transferred transgene, suggesting that the RGD capsid modification may be useful in developing Ad-based vaccines. 相似文献
33.
Cell cycle and biochemical effects of PD 0183812. A potent inhibitor of the cyclin D-dependent kinases CDK4 and CDK6 总被引:5,自引:0,他引:5
Fry DW Bedford DC Harvey PH Fritsch A Keller PR Wu Z Dobrusin E Leopold WR Fattaey A Garrett MD 《The Journal of biological chemistry》2001,276(20):16617-16623
Progression through the G1 phase of the cell cycle requires phosphorylation of the retinoblastoma gene product (pRb) by the cyclin D-dependent kinases CDK4 and CDK6, whose activity can specifically be blocked by the CDK inhibitor p16(INK4A). Misregulation of the pRb/cyclin D/p16(INK4A) pathway is one of the most common events in human cancer and has lead to the suggestion that inhibition of cyclin D-dependent kinase activity may have therapeutic value as an anticancer treatment. Through screening of a chemical library, we initially identified the [2,3-d]pyridopyrimidines as inhibitors of CDK4. Chemical modification resulted in the identification of PD 0183812 as a potent and highly selective inhibitor of both CDK4 and CDK6 kinase activity, which is competitive with ATP. Flow cytometry experiments showed that of the cell lines tested, only those expressing pRb demonstrated a G1 arrest when treated with PD 0183812. This arrest correlated in terms of incubation time and potency with a loss of pRb phosphorylation and a block in proliferation, which was reversible. These results suggest a potential use of this chemical class of compounds as therapeutic agents in the treatment of tumors with functional pRb, possessing cell cycle aberrations in other members of the pRb/cyclin D/p16(INK4A) pathway. 相似文献
34.
Purification and characterization of rat hippocampal CA3-dendritic spines associated with mossy fiber terminals 总被引:3,自引:0,他引:3
We report a revised and improved isolation procedure for CA3-dendritic spines, most of them still in association with mossy fiber terminals resulting in a 7.5-fold enrichment over nuclei and a 29-fold enrichment over myelin. Additionally, red blood cells, medullated fibers, mitochondria and small synaptosomes were significantly depleted. We show by high resolution electron microscopy that this subcellular fraction contains numerous dendritic spines with a rich ultrastructure, e.g. an intact spine apparatus, membranous organelles, free and membrane-bound polyribosomes, endocytic structures and mitochondria. This improved experimental system will allow us to study aspects of post-synaptic functions at the biochemical and molecular level. 相似文献
35.
Kostanski LK Keller DM Hamielec AE 《Journal of biochemical and biophysical methods》2004,58(2):159-186
Recent developments are reviewed in size exclusion chromatographic calibration methodologies, including direct calibration by using narrow and broad polymer standards and various instrumental methods (nuclear magnetic resonance, mass spectrometry, light scattering) as well as universal calibration with and without viscometry detectors, for simple and complex polymers. 相似文献
36.
Pleva L Sír M Madeja R 《Biomedical papers of the Medical Faculty of the University Palacky, Olomouc, Czechoslovakia》2004,148(1):75-79
In the statement authors want to draw attention to the possibilities of treatment of periprosthetic fractures of femur. They present their own experiences with the treatment of these fractures by using various types of internal and external fixation evaluated from 1996 to 2003. They present some less common types of internal fixation as e.g. fixation by clamp plates. 相似文献
37.
Dorner GT Garhofer G Kiss B Polska E Polak K Riva CE Schmetterer L 《American journal of physiology. Heart and circulatory physiology》2003,285(2):H631-H636
The purpose of the present study was to investigate the contribution of basal nitric oxide (NO) on retinal vascular tone in humans. In addition, we set out to elucidate the role of NO in flicker-induced retinal vasodilation in humans. Twelve healthy young subjects were studied in a three-way crossover design. Subjects received an intravenous infusion of either placebo or NG-monomethyl-L-arginine (L-NMMA; 3 or 6 mg/kg over 5 min), an inhibitor of NO synthase. Thereafter, diffuse luminance flicker was consecutively performed for 16, 32, and 64 s at a frequency of 8 Hz. The effect of L-NMMA on retinal arterial and venous diameter was assessed under resting conditions and during the hyperemic flicker response. Retinal vessel diameter was measured with a Zeiss retinal vessel analyzer. L-NMMA significantly reduced arterial diameter (3 mg/kg: -2%; 6 mg/kg: -4%, P < 0.001) and venous diameter (3 mg/kg: -5%; 6 mg/kg: -8%, P < 0.001). After placebo infusion, flicker induced a significant increase in retinal vessel diameter (P < 0.001). At a flicker duration of 64 s, arterial diameter increased by 4% and venous diameter increased by 3%. L-NMMA did not abolish these hyperemic responses but blunted venous vasodilation (P = 0.017) and arterial vasodilation (P = 0.02) in response to flicker stimulation. Our data indicate that NO contributes to basal retinal vascular tone in humans. In addition, NO appears to play a role in flicker-induced vasodilation of the human retinal vasculature. 相似文献
38.
Adenoviruses (Ad) must deliver their genomes to the nucleus of the target cell to initiate an infection. Following entry into the cell and escape from the endosome, Ad traffics along the microtubule cytoskeleton toward the nucleus. In the final step in Ad trafficking, Ad must leave the microtubule and establish an association with the nuclear envelope. We hypothesized that in cells lacking a nucleus, the capsid moves to and associates with the microtubule organizing center (MTOC). To test this hypothesis, we established an experimental system to examine Ad trafficking in enucleated cells compared to Ad trafficking in intact, mock-enucleated cells. Enucleation of a monolayer of A549 human lung epithelial cells was accomplished by depolymerization of the actin cytoskeleton followed by centrifugation. Upon infection of enucleated cells with Cy3-labeled Ad, the majority of Ad capsid trafficked to a discrete, centrally located site which colocalized with pericentrin, a component of the MTOC. MTOC-associated Ad had escaped from endosomes and thus had direct access to MTOC components. Ad localization at this site was sensitive to the microtubule-depolymerizing agent nocodazole, but not to the microfilament-depolymerizing agent cytochalasin B, indicating that intact microtubules were required to maintain the localization with the MTOC. Ad localization to the MTOC in the enucleated cells was stable, as demonstrated by continuing Ad localization with pericentrin for more than 5 h after infection, a strong preference for Ad arrival at rather than Ad departure from the MTOC, and minimal redistribution of Ad between MTOCs within a single cell. In summary, the data demonstrate that the Ad capsid establishes a stable interaction with the MTOC when a nucleus is not present, suggesting that dissociation of Ad from microtubules likely requires nuclear factors. 相似文献
39.
Krumme D Budde H Hecht HJ Menge U Ohlenschläger O Ross A Wissing J Wray V Flohé L 《Biochemistry》2003,42(50):14720-14728
Tryparedoxins (TXNs) are trypanothione-dependent peroxiredoxin oxidoreductases involved in hydroperoxide detoxification that have been shown to determine virulence in trypanosomatids. The structure of (15)N,(13)C-doubly-labeled, C-terminally-His-tagged tryparedoxin 1 from Crithidia fasciculata (Cf TXN1) was elucidated by three-dimensional NMR spectroscopy. Global folding was found to be similar to the crystal structure, but regions near the active site, especially the onset of helix alpha1 with the redox-active Cys 43 and helix alpha2 relevant to substrate binding, were less well defined in solution. The redox-inactive inhibitory substrate analogue N(1),N(8)-bis(ophthalmyl)spermidine was used to study the substrate/TXN interaction by two-dimensional (1)H,(15)N NMR spectroscopy. The NMR data complemented by molecular modeling revealed several alternative modes of ligand binding. The results confirm and extend the concept of TXN action and specificity derived from X-ray analysis and site-directed mutagenesis and thus improve the rational basis for inhibitor design. 相似文献
40.
Tettigonia ussuriana and T. dolichopoda maritima differ in the length of tegmina, details in venation, and in females in details of the subgenital plate. The two species of the genus Tettigonia have the same number and morphology of autosomes but a different morphology of the X chromosome: in T. ussuriana it is metacentric, whereas in T. dolichopoda maritima acrocentric. In both species, euchromatic zones and breaks of one or to chromatids during meiosis and mitosis in the X chromosome were observed. Additionally, B chromosomes were noted in most individuals of both species. 相似文献