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971.
HrpN(EP), from the gram-negative pathogen, Erwinia pyrifoliae, is a member of the harpin group of proteins, inducing pathogen resistance and hypersensitive cell death in plants. When the hrpN(EP) gene driven by the OsCc1 promoter was introduced into tobacco plants via Agrobacterium-mediated transformation, their resistance to the necrotrophic fungal pathogen, Botrytis cinerea, increased. Resistance to B. cinerea was correlated with enhanced induction of SA-dependent genes such as PR-1a, PR2, PR3 and Chia5, of JA-dependent genes such as PR-1b, and of genes related to ethylene production, such as NT-EFE26, NT-1A1C, DS321, NT-ACS1 and NT-ACS2. However the expression of NPR1, which is thought to be essential for multiple-resistance, did not increase. Since the pattern of expression of defense-related genes in hrpN(EP)-expressing tobacco differed from that in plants expressing hpaG(Xoo) from Xanthomonas oryzae pv. Oryzae, these results suggest that different harpins can affect the expression of different defense-related genes, as well as resistance to different plant pathogens. 相似文献
972.
Shim JH Sung KJ Cho MC Choi WA Yang Y Lim JS Yoon DY 《Journal of microbiology and biotechnology》2007,17(9):1513-1520
Beta-1,3-glucans enhance immune reactions such as antitumor, antibacterial, antiviral, anticoagulatory, and wound healing activities. beta-1,3-Glucans have various functions depending on the molecular weight, degree of branching, conformation, water solubility, and intermolecular association. The molecular weight of the soluble glucan was about 15,000 as determined by a high-performance size exclusion chromatography. From the infrared (IR) and 13C NMR analytical data, the purified soluble glucan was found to exclusively consist of beta-D-glucopyranose with 1,3 linkage. We tested the immunestimulating activities of the soluble beta-1,3-glucan extracted from Agrobacterium sp. R259 KCTC 1019 and confirmed the following activities. IFN-gamma and each cytokines were induced in the spleens and thymus of mice treated with soluble beta-1,3-glucan. Adjuvant effect was observed on antibody production. Nitric oxide was synthesized in monocytic cell lines treated with beta-1,3-glucan. The cytotoxic and antitumor effects were observed on various cancer cell lines and ICR mice. These results strongly suggested that this soluble beta-1,3-glucan could be a good candidate for an immune-modulating agent. 相似文献
973.
Woo HJ Lee YS Park SJ Lim JT Jang KH Choi EH Choi YG Hwang UW 《Molecules and cells》2007,23(2):182-191
The complete mitochondrial genome of a troglobite millipede Antrokoreana gracilipes (Verhoeff, 1938) (Dipolopoda, Juliformia, Julida) was sequenced and characterized. The genome (14,747 bp) contains 37 genes (2 ribosomal RNA genes, 22 transfer RNA genes and 13 protein-encoding genes) and two large non-coding regions (225 bp and 31 bp), as previously reported for two diplopods, Narceus annularus (order Spirobolida) and Thyropygus sp. (order Spirostreptida). The A + T content of the genome is 62.1% and four tRNAs (tRNA(Ser(AGN)), tRNA(Cys), tRNA(Ile) and tRNA(Met)) have unusual and unstable secondary structures. Whereas Narceus and Thyropygus have identical gene arrangements, the tRNA(Thr) and tRNA(Trp) of Antrokoreana differ from them in their orientations and/or positions. This suggests that the Spirobolida and Spirostreptida are more closely related to each other than to the Dipolopoda. Three scenarios are proposed to account for the unique gene arrangement of Antrokoreana. The data also imply that the Duplication and Nonrandom Loss (DNL) model is applicable to the order Julida. Bayesian inference (BI) and maximum likelihood (ML) analyses using amino acid sequences deduced from the 12 mitochondrial protein-encoding genes (excluding ATP8) support the view that the three juliformian members are monophyletic (BI 100%; ML 100%), that Thyropygus (Spirostreptida) and Narceus (Spirobolida) are clustered together (BI 100%; ML 83%), and that Antrokoreana (Julida) is a sister of the two. However, due to conflict with previous reports using cladistic approaches based on morphological characteristics, further studies are needed to confirm the close relationship between Spirostreptida and Spirobolida. 相似文献
974.
Ameliorating effect of Gardenia jasminoides extract on amyloid beta peptide-induced neuronal cell deficit 总被引:1,自引:0,他引:1
Choi SJ Kim MJ Heo HJ Hong B Cho HY Kim YJ Kim HK Lim ST Jun WJ Kim EK Shin DH 《Molecules and cells》2007,24(1):113-118
The brains of Alzheimer's disease (AD) patients are characterized by large deposits of amyloid beta peptide (Abeta). Abeta is known to increase free radical production in nerve cells, leading to cell death that is characterized by lipid peroxidation, free radical formation, protein oxi-dation, and DNA/RNA oxidation. In this study, we selected an extract of Gardenia jasminoides by screening, and investigated its ameliorating effects on Abeta-induced oxidative stress using PC12 cells. The effects of the extract were evaluated using the 2,7 -dichlorofluorescein diacetate (DCF-DA) assay and the 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. To find the active component, the ethanol extract was partitioned with hexane, chloroform, and ethyl acetate, respectively, and the active component was purified by silica-gel column chromatography and HPLC. The results suggested that Gardenia jasminoides extract can reduce the cytotoxicity of Abeta in PC 12 cells, possibly by reducing oxidative stress. 相似文献
975.
Jaekal J Abraham E Azam T Netea MG Dinarello CA Lim JS Yang Y Yoon DY Kim SH 《Journal of microbiology and biotechnology》2007,17(11):1862-1867
An individual's immune response is critical for host protection from many different pathogens, and the responsiveness can be assessed by the amount of cytokine production upon stimulating bacterial components such as lipopolysaccharide (LPS). The difference between individuals in their peripheral blood mononuclear cells (PBMC) responsiveness to LPS, a Gram-negative endotoxin, was investigated from 27 healthy individuals. We observed a large variation in IFNgamma production among different individuals. The PBMC of the consistently three highest and three lowest IFNgamma producers were investigated. Since previous studies described that a single point mutation in the coding region of TLR2 and TLR4 is linked to the individual responsiveness to pathogenic bacterial infections, we first examined the known point mutations in the coding region of TLR2Pro681His, TLR4Pro714His located in the cytoplasmic regions of the Toll-like domain as well as TLR4Asp299Gly located in the extracellular region. None of these mutations were associated with an individual's responsiveness to LPS, despite the presence of TLR4Asp299Gly mutation. Further investigation revealed that the variation of PBMC responsiveness to LPS among healthy individuals was due to constitutive expression levels of TLR4 and TLR2. This result is consistent with an aging-related low expression of Toll-like receptors in the mouse model of LPS responsiveness. The present study therefore suggests that the constitutive expression levels of TLR2 and TLR4 may contribute to the individual response to LPS. 相似文献
976.
The quality of pharmaceutical products such as ginseng is important for ensuring consumer safety and efficacy. Ginseng is
an expensive herb, and adulteration with other cheaper products may occur. Quality assurance of ginseng is needed since many
of its commercial products now come in various formulations such as capsules, powder, softgels and tea. Thus traditional means
of authentication via smell, taste or physical appearance are hardly reliable. Herbs like ginseng tend to exhibit characteristic
infrared fingerprints due to their different chemical constituents. Here we report for the first time a rapid means of distinguishing
American and Asian ginsengs from two morphological fakes – sawdust and Platycodon grandiflorum, via pattern differences and principal component analysis of their infrared spectra. Our results show that ginseng can be
distinguished from both sawdust and Platycodon grandiflorum, hence there is a potential of using infrared spectroscopy as a novel analytical technique in the authentication of ginseng. 相似文献
977.
Glia maturation factor (GMF), a highly conserved brain-specific protein, isolated, sequenced and cloned in our laboratory.
Overexpression of GMF in astrocytes induces the production and secretion of granulocyte-macrophage-colony stimulating factor
(GM-CSF), and subsequent immune activation of microglia, expression of several proinflammatory genes including major histocompatibility
complex proteins, IL-1β, and MIP-1β, all associated with the development of experimental autoimmune encephalomyelitis (EAE),
the animal model for multiple sclerosis. Based on GMF’s ability to activate microglia and induce well-established proinflammatory
mediators, including GM-CSF, we hypothesize that GMF is involved in the pathogenesis of inflammatory disease EAE. In this
present investigation, using GMF-deficient mice, we study the role of GMF and how the lack of GMF affects the EAE disease.
Our results show a significant decrease in incidence, delay in onset, and reduced severity of EAE in GMF-deficient mice, and
support the hypothesis that GMF plays a major role in the pathogenesis of disease. 相似文献
978.
This article discusses a culturally specific response to traumatic events: orthostatic panic attacks among Vietnamese refugees. We compared the rate and severity of orthostatic panic as well as the rates and severity of associated flashbacks a month before and a month after September 11, 2001. After that date, the rate and severity of orthostatic panic greatly increased, as did the rate and severity of associated flashbacks. The central role of orthostatic panic as a response to traumatic events is illustrated through a patient's vignette. An explanation of why September 11 so profoundly influenced this population is adduced, including an explanation of why it resulted in considerable worsening of orthostatic panic. 相似文献
979.
Switch of cadherin expression from E- to N-type during the activation of rat hepatic stellate cells 总被引:3,自引:3,他引:0
The activation of hepatic stellate cell (HSC) is a common pathway leading to hepatic fibrosis. However, the molecular mechanisms
underlying HSC activation remain obscure. To elucidate the nature of the HSC activation, we investigated the expression of
E-cadherin and its switch to N-cadherin during rat HSC activation, in vivo and in vitro. Immunohistochemical and immunocytochemical
staining were performed to identify the expressions of E-cadherin, N-cadherin, and β-catenin in rat HSCs, in vivo and in vitro.
Serial changes in the expressions of these adhesion molecules during the spontaneous activation of cultured rat HSCs were
also demonstrated by RT-PCR and by immunoblotting. E-cadherin and β-catenin were expressed on opposing cell membranes of GFAP-positive
rat HSCs and adjacent hepatocytes in vivo, and between desmin-positive rat HSCs in vitro. With the progression of rat HSC
activation in tissue and in culture, E-cadherin disappeared gradually, whereas N-cadherin appeared at the cell periphery.
The results of RT-PCR and immunoblotting were concordant with immunocytochemistry findings. In conclusion, resting rat HSCs
express E-cadherin and β-catenin both in vivo and in vitro, and E-cadherin switches to N-cadherin during HSC activation. These
results suggest that HSC activation represents transdifferentiation from an epithelial to a mesenchymal phenotype. 相似文献
980.
Lim BO Lee JH Ko NY Mun SH Kim JW Kim do K Kim JD Kim BK Kim HS Her E Lee HY Choi WS 《Experimental biology and medicine (Maywood, N.J.)》2007,232(11):1425-1431
The antiallergic activity of Polygoni cuspidati radix (PR) and the mechanism of action by which it functions were investigated in this study. The extract of PR exhibited potent inhibitory activity in mast cells; its IC50 values were 62 +/- 2.1 microg/ml for RBL-2H3 mast cells and 46 +/- 3.2 microg/m for bone marrow-derived mast cells by antigen stimulation, and it also suppressed the expression of tumor necrosis factor-alpha and interleukin-4 in RBL-2H3 cells. According to the in vivo animal allergy model, it inhibited a local allergic reaction, passive cutaneous anaphylaxis, in a dose-dependent manner. With regard to its mechanism of action, PR inhibited the activating phosphorylation of Syk, a key signaling protein for the activation of mast cells. It also suppressed Akt and the mitogen-activated protein kinases ERK1/2, p38, and JNK, which are critical for the production of various inflammatory cytokines in mast cells. The results of the study indicate that the antiallergic activity of PR is mediated through the inhibition of histamine release and allergic cytokine production by the inhibition of Syk activating phosphorylation in mast cells. 相似文献