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951.
Kaittanis C Banerjee T Santra S Santiesteban OJ Teter K Perez JM 《Bioconjugate chemistry》2011,22(2):307-314
When covalently bound to an appropriate ligand, iron oxide nanoparticles can bind to a specific target of interest. This interaction can be detected through changes in the solution's spin-spin relaxation times (T2) via magnetic relaxation measurements. In this report, a strategy of molecular mimicry was used in order to identify targeting ligands that bind to the cholera toxin B subunit (CTB). The cellular CTB-receptor, ganglioside GM1, contains a pentasaccharide moiety consisting in part of galactose and glucose units. We therefore predicted that CTB would recognize carbohydrate-conjugated iron oxide nanoparticles as GM1 mimics, thus producing a detectable change in the T2 relaxation times. Magnetic relaxation experiments demonstrated that CTB interacted with the galactose-conjugated nanoparticles. This interaction was confirmed via surface plasmon resonance studies using either the free or nanoparticle-conjugated galactose molecule. The galactose-conjugated nanoparticles were then used as CTB sensors achieving a detection limit of 40 pM. Via magnetic relaxation studies, we found that CTB also interacted with dextran-coated nanoparticles, and surface plasmon resonance studies also confirmed this interaction. Additional experiments demonstrated that the dextran-coated nanoparticle can also be used as CTB sensors and that dextran can prevent the internalization of CTB into GM1-expressing cells. Our work indicates that magnetic nanoparticle conjugates and magnetic relaxation detection can be used as a simple and fast method to identify targeting ligands via molecular mimicry. Furthermore, our results show that the dextran-coated nanoparticles represent a low-cost approach for CTB detection. 相似文献
952.
Banerjee Y Taranikanti V Alriyami M 《Trends in molecular medicine》2011,17(4):175-6; author reply 176-7
953.
Bromo-benzothiophene carboxamide derivatives have been shown in the preceding article to inhibit Plasmodium falciparum Enoyl-ACP reductase. Here, we report bromo-benzothiophene carboxamide derivatives as potent inhibitors of Plasmodium asexual blood-stages in vitro as well as in vivo in the mouse model. These compounds specifically impair the development of metabolically active trophozoite stage of intraerythrocytic cycle and the intravenous administration of 3-bromo-N-(4-fluorobenzyl)-benzo[b]thiophene-2-carboxamide (compound 6) enhances the longevity of P. berghei infected mice by 2 weeks compared to disease control animals thereby preventing the onset of ataxia and convulsions in treated mice. These compounds thus hold promise for the development of potent antimalarials. 相似文献
954.
Zurawel A Moore EE Peltz ED Jordan JR Damle S Dzieciatkowska M Banerjee A Hansen KC 《Clinical proteomics》2011,8(1):1
Experiments show that upon traumatic injury the composition of mesenteric lymph changes such that it initiates an immune response
that can ultimately result in multiple organ dysfunction syndrome (MODS). To identify candidate protein mediators of this
process we carried out a quantitative proteomic study on mesenteric lymph from a well characterized rat shock model. We analyzed
three animals using analytical 2D differential gel electrophoresis. Intra-animal variation for the majority of protein spots
was minor. Functional clustering of proteins revealed changes arising from several global classes that give novel insight
into fundamental mechanisms of MODS. Mass spectrometry based proteomic analysis of proteins in mesenteric lymph can effectively
be used to identify candidate mediators and loss of protective agents in shock models. 相似文献
955.
Yamauchi Y Boukari H Banerjee I Sbalzarini IF Horvath P Helenius A 《PLoS pathogens》2011,7(10):e1002316
Influenza A virus (IAV) enters host cells by endocytosis followed by acid-activated penetration from late endosomes (LEs). Using siRNA silencing, we found that histone deacetylase 8 (HDAC8), a cytoplasmic enzyme, efficiently promoted productive entry of IAV into tissue culture cells, whereas HDAC1 suppressed it. HDAC8 enhanced endocytosis, acidification, and penetration of the incoming virus. In contrast, HDAC1 inhibited acidification and penetration. The effects were connected with dramatic alterations in the organization of the microtubule system, and, as a consequence, a change in the behavior of LEs and lysosomes (LYs). Depletion of HDAC8 caused loss of centrosome-associated microtubules and loss of directed centripetal movement of LEs, dispersing LE/LYs to the cell periphery. For HDAC1, the picture was the opposite. To explain these changes, centrosome cohesion emerged as the critical factor. Depletion of HDAC8 caused centrosome splitting, which could also be induced by depleting a centriole-linker protein, rootletin. In both cases, IAV infection was inhibited. HDAC1 depletion reduced the splitting of centrosomes, and enhanced infection. The longer the distance between centrosomes, the lower the level of infection. HDAC8 depletion was also found to inhibit infection of Uukuniemi virus (a bunyavirus) suggesting common requirements among late penetrating enveloped viruses. The results established class I HDACs as powerful regulators of microtubule organization, centrosome function, endosome maturation, and infection by IAV and other late penetrating viruses. 相似文献
956.
957.
Mechanisms and scenarios of pattern formation in predator–prey systems have been a focus of many studies recently as they
are thought to mimic the processes of ecological patterning in real-world ecosystems. Considerable work has been done with
regards to both Turing and non-Turing patterns where the latter often appears to be chaotic. In particular, spatiotemporal
chaos remains a controversial issue as it can have important implications for population dynamics. Most of the results, however,
were obtained in terms of ‘traditional’ predator–prey models where the per capita predation rate depends on the prey density
only. A relatively new family of ratio-dependent predator–prey models remains less studied and still poorly understood, especially
when space is taken into account explicitly, in spite of their apparent ecological relevance. In this paper, we consider spatiotemporal
pattern formation in a ratio-dependent predator–prey system. We show that the system can develop patterns both inside and
outside of the Turing parameter domain. Contrary to widespread opinion, we show that the interaction between two different
type of instability, such as the Turing–Hopf bifurcation, does not necessarily lead to the onset of chaos; on the contrary,
the emerging patterns remain stationary and almost regular. Spatiotemporal chaos can only be observed for parameters well
inside the Turing–Hopf domain. We then investigate the relative importance of these two instability types on the onset of
chaos and show that, in a ratio-dependent predator–prey system, the Hopf bifurcation is indeed essential for the onset of
chaos whilst the Turing instability is not. 相似文献
958.
Lactoperoxidase (LPO), a member of the peroxidase-cyclooxygenase superfamily, is found in multiple human exocrine secretions and acts as a first line of defense against invading microorganisms by production of antimicrobial oxidants. Because of its ability to efficiently catalyze one- and two-electron oxidation reactions of inorganic and organic compounds, the heme peroxidase is widely used in food biotechnology, cosmetic industry, and diagnostic kits. In order to probe its structural integrity, conformational, and thermal stability, we have undertaken a comprehensive investigation by using complementary biophysical techniques including UV-Vis, circular dichroism and fluorescence spectroscopy as well as differential scanning calorimetry (DSC). The oxidoreductase exhibits a high chemical and thermal stability under oxidizing conditions but is significantly destabilized by addition of DTT. Due to its unique ester bonds between the prosthetic group and the protein as well as six intra-chain disulfides, unfolding of the central compact (-helical core occurs concomitantly with denaturation of the heme cavity. The corresponding enthalpic and entropic contributions to the free enthalpy of unfolding are presented. Together with spectroscopic data they will be discussed with respect to the known structure of bovine LPO and homologous myeloperoxidase as well as to its practical application. 相似文献
959.
Banerjee S Kambhampati S Haque I Banerjee SK 《Journal of cell communication and signaling》2011,5(4):317-324
It is estimated that one in eight women will be affected with cancer during their lives, which means over 1 million women
worldwide will be diagnosed with breast cancer in the year of 2011. Roughly, 70% of breast cancer will be estrogen receptor-alpha
(ER-α) positive. The presence of ER-α is associated with better prognosis and is able to determine if tumors will respond
to the estrogen-blocking/ER-antagonist drug Tamoxifen (TAM). However, a significant fraction of ER-positive tumors respond
with minimal or no response to TAM. It is unclear why some breast cancer cells resist TAM and how to make these cells respond.
Early evidence suggests Pomegranate fruit extracts (PFEs) exhibit an anticancer effect against some cancers. The objective
of the study was to determine whether PFEs may able to enhance/sensitize the TAM’s effect in ER-positive MCF-7 breast cancer
cells. To test the hypothesis, we determined the effect of PFEs on sensitive and TAM-resistant-MCF-7 cell viability and cell
death in the presence or absence of TAM under estrogenic or non-estrogenic culture environment. The present studies demonstrated
that PFEs enhance the TAM action in both sensitive and TAM-resistant MCF-7 cells through the inhibition of cell viability
(regular or estrogen-induced) by inducing cell-death machinery. Collectively, the results showed for the first time that pomegranate
combined with TAM may represent a novel and a powerful approach to enhance and sensitize TAM action. 相似文献
960.
Wang Z Banerjee S Ahmad A Li Y Azmi AS Gunn JR Kong D Bao B Ali S Gao J Mohammad RM Miele L Korc M Sarkar FH 《PloS one》2011,6(6):e20537