全文获取类型
收费全文 | 1255篇 |
免费 | 92篇 |
国内免费 | 2篇 |
出版年
2023年 | 10篇 |
2022年 | 8篇 |
2021年 | 34篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 32篇 |
2017年 | 27篇 |
2016年 | 51篇 |
2015年 | 70篇 |
2014年 | 72篇 |
2013年 | 110篇 |
2012年 | 95篇 |
2011年 | 107篇 |
2010年 | 63篇 |
2009年 | 60篇 |
2008年 | 88篇 |
2007年 | 76篇 |
2006年 | 70篇 |
2005年 | 50篇 |
2004年 | 54篇 |
2003年 | 50篇 |
2002年 | 37篇 |
2001年 | 41篇 |
2000年 | 20篇 |
1999年 | 25篇 |
1998年 | 5篇 |
1997年 | 7篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有1349条查询结果,搜索用时 15 毫秒
991.
Phosphatidic acid (PA) is implicated in pathophysiological processes associated with cellular signaling events and inflammation, which include the expressional regulation of numerous genes. Here, we show that PA stimulation increases matrix metalloproteinase-9 (MMP-9) expression in macrophages through tumor necrosis factor (TNF)-alpha signaling. We performed antibody array analysis on proteins from macrophages stimulated with PA. PA was found to induce the production of TNF-alpha, but not of TNF receptor (TNFR)1 and TNFR2 in a time-dependent manner and stimulated significant, though delayed, MMP-9 expression. PA induced the phosphorylations of both ERK1/2 and p38, but not of c-jun amino-terminal kinase. Moreover, only ERK1/2 inhibition by U0126 suppressed PA-induced TNF-alpha production and MMP-9 expression. Neutralizing TNF-alpha, TNFR1 or TNFR2 antibodies significantly suppressed PA-induced MMP-9 expression, suggesting that the production of TNF-alpha in response to PA preceded the expression of MMP-9. Moreover, lipopolysaccharide-induced PA also led to TNF-alpha release and resulted in MMP-9 expression. Taken together, these observations suggest that PA may play a role in MMP-9 regulation through ERKs/TNF-alpha/TNFRs-dependent signaling pathway. 相似文献
992.
Kim MS Kim HS Kim YS Baek KH Oh HW Hahn KW Bae RN Lee IJ Joung H Jeon JH 《Plant cell reports》2007,26(10):1717-1725
A higher concentration of H2O2 was detected in the sense transgenic potato plant (SS4) with the lily chCu,ZnSOD sequence, whereas higher levels of O2− was detected in the antisense transgenic plant (SA1) than the WT plant. The elongation growth in SA1 was significantly inhibited
by treatment with diphenyleneiodonium, an inhibitor of O2− generation, and promoted in the SS4 on treatment with herbicide methyl viologen, a generator of apoplastic O2−. Higher concentrations of GAs were detected during plant growth and the early stage of tuberization in SA1. Complete recovery
of the above elongation growth and microtuberization pattern in transgenic plants following treatment of GA3 or an inhibitor of gibberellin synthesis, paclobutrazol, indicate that these changes were mainly caused by active GA levels.
In conclusion, a specific ROS (O2− ) acts as a signal transducer via GA biosynthetic pathways for the regulation of plant growth and tuber development of potato. 相似文献
993.
Lee J Nam J Park HC Na G Miura K Jin JB Yoo CY Baek D Kim DH Jeong JC Kim D Lee SY Salt DE Mengiste T Gong Q Ma S Bohnert HJ Kwak SS Bressan RA Hasegawa PM Yun DJ 《The Plant journal : for cell and molecular biology》2007,49(1):79-90
Reversible modifications of target proteins by small ubiquitin-like modifier (SUMO) proteins are involved in many cellular processes in yeast and animals. Yet little is known about the function of sumoylation in plants. Here, we show that the SIZ1 gene, which encodes an Arabidopsis SUMO E3 ligase, regulates innate immunity. Mutant siz1 plants exhibit constitutive systemic-acquired resistance (SAR) characterized by elevated accumulation of salicylic acid (SA), increased expression of pathogenesis-related (PR) genes, and increased resistance to the bacterial pathogen Pseudomonas syringae pv. tomato (Pst) DC3000. Transfer of the NahG gene to siz1 plants results in reversal of these phenotypes back to wild-type. Analyses of the double mutants, npr1 siz1, pad4 siz1 and ndr1 siz1 revealed that SIZ1 controls SA signalling. SIZ1 interacts epistatically with PAD4 to regulate PR expression and disease resistance. Consistent with these observations, siz1 plants exhibited enhanced resistance to Pst DC3000 expressing avrRps4, a bacterial avirulence determinant that responds to the EDS1/PAD4-dependent TIR-NBS-type R gene. In contrast, siz1 plants were not resistant to Pst DC3000 expressing avrRpm1, a bacterial avirulence determinant that responds to the NDR1-dependent CC-NBS-type R gene. Jasmonic acid (JA)-induced PDF1.2 expression and susceptibility to Botrytis cinerea were unaltered in siz1 plants. Taken together, these results demonstrate that SIZ1 is required for SA and PAD4-mediated R gene signalling, which in turn confers innate immunity in Arabidopsis. 相似文献
994.
Ji Yong Jang Su Bin Wang Ji Hyun Min Yun Hee Chae Jin Young Baek Dae-Yeul Yu Tong-Shin Chang 《The Journal of biological chemistry》2015,290(18):11432-11442
Collagen-induced platelet signaling is mediated by binding to the primary receptor glycoprotein VI (GPVI). Reactive oxygen species produced in response to collagen have been found to be responsible for the propagation of GPVI signaling pathways in platelets. Therefore, it has been suggested that antioxidant enzymes could down-regulate GPVI-stimulated platelet activation. Although the antioxidant enzyme peroxiredoxin II (PrxII) has emerged as having a role in negatively regulating signaling through various receptors by eliminating H2O2 generated upon receptor stimulation, the function of PrxII in collagen-stimulated platelets is not known. We tested the hypothesis that PrxII negatively regulates collagen-stimulated platelet activation. We analyzed PrxII-deficient murine platelets. PrxII deficiency enhanced GPVI-mediated platelet activation through the defective elimination of H2O2 and the impaired protection of SH2 domain-containing tyrosine phosphatase 2 (SHP-2) against oxidative inactivation, which resulted in increased tyrosine phosphorylation of key components for the GPVI signaling cascade, including Syk, Btk, and phospholipase Cγ2. Interestingly, PrxII-mediated antioxidative protection of SHP-2 appeared to occur in the lipid rafts. PrxII-deficient platelets exhibited increased adhesion and aggregation upon collagen stimulation. Furthermore, in vivo experiments demonstrated that PrxII deficiency facilitated platelet-dependent thrombus formation in injured carotid arteries. This study reveals that PrxII functions as a protective antioxidant enzyme against collagen-stimulated platelet activation and platelet-dependent thrombosis. 相似文献
995.
First Report of Aster Yellows Phytoplasma (16SrI‐B) Associated with Witches' Broom Disease of Melia azedarach var. japonica in Korea 下载免费PDF全文
Sang‐Sub Han So‐Jin Baek Sang‐Hyun Lee Sang‐Tae Seo Kamala‐Kannan Seralathan 《Journal of Phytopathology》2015,163(11-12):1055-1058
Melia azedarach var. japonica trees with leaf yellowing, small leaves and witches' broom were observed for the first time in Korea. A phytoplasma from the symptomatic leaves was identified based on the 16Sr DNA sequence as a member of aster yellows group, ribosomal subgroup 16SrI‐B. Sequence analyses of more variable regions such as 16S–23S intergenic spacer region, secY gene, ribosomal protein (rp) operon and tuf gene showed 99.5?100% nucleotide identity to several GenBank sequences of group 16SrI phytoplasmas. Phylogenetic analysis confirmed that the Melia azedarach witches' broom phytoplasma belongs to aster yellows group. 相似文献
996.
Jang M Park BC Lee do H Bae KH Cho S Park HS Lee BR Parki SG 《Journal of microbiology and biotechnology》2007,17(2):359-363
Because of the importance of the type III protein-secretion system in bacteria-plant interaction, its function in bacterial pathogenesis of plants has been intensively studied. To identify bacterial proteins interacting with Xanthomonas hrp gene products that are involved in pathogenicity, we performed the glutathione-bead binding analysis of Xanthomonas lysates containing GST-tagged Hrp proteins. Analysis of glutathione-bead bound proteins by 1-DE and MALDI-TOF has demonstrated that Avr proteins, RecA, and several components of the type III secretion system interact with HrpB protein. This proteomic approach could provide a powerful tool in finding interaction partners of Hrp proteins whose roles in host-pathogen interaction need further studies. 相似文献
997.
998.
Monitoring of microbial diversity and activity during bioremediation of crude oil-contaminated soil with different treatments 总被引:1,自引:0,他引:1
Baek KH Yoon BD Kim BH Cho DH Lee IS Oh HM Kim HS 《Journal of microbiology and biotechnology》2007,17(1):67-73
The present study compared the microbial diversity and activity during the application of various bioremediation processes to crude oil-contaminated soil. Five different treatments, including natural attenuation (NA), biostimulation (BS), biosurfactant addition (BE), bioaugmentation (BA), and a combined treatment (CT) of biostimulation, biosurfactant addition, and bioaugmentation, were used to analyze the degradation rate and microbial communities. After 120 days, the level of remaining hydrocarbons after all the treatments was similar, however, the highest rate (k) of total petroleum hydrocarbon (TPH) degradatioN was observed with the CT treatment (P < 0.05). The total bacterial counts increased during the first 2 weeks with all the treatments, and then remained stable. The bacterial communities and alkane monooxygenase gene fragment, alkB, were compared by denaturing gradient gel electrophoresis (DGGE). The DGGE analyses of the BA and CT treatments, which included Nocardia sp. H17-1, revealed a simple dominant population structure, compared with the other treatments. The Shannon-Weaver diversity index (H') and Simpson dominance index (D), calculated from the DGGE profiles using 16S rDNA, showed considerable qualitative differences in the community structure before and after the bioremediation treatment as well as between treatment conditions. 相似文献
999.
1000.
Ginkgolic Acid Inhibits Invasion and Migration and TGF‐β‐Induced EMT of Lung Cancer Cells Through PI3K/Akt/mTOR Inactivation 下载免费PDF全文