全文获取类型
收费全文 | 620篇 |
免费 | 33篇 |
出版年
2023年 | 3篇 |
2022年 | 6篇 |
2021年 | 22篇 |
2020年 | 14篇 |
2019年 | 9篇 |
2018年 | 14篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 34篇 |
2014年 | 36篇 |
2013年 | 36篇 |
2012年 | 45篇 |
2011年 | 42篇 |
2010年 | 15篇 |
2009年 | 14篇 |
2008年 | 27篇 |
2007年 | 19篇 |
2006年 | 15篇 |
2005年 | 22篇 |
2004年 | 18篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 14篇 |
2000年 | 24篇 |
1999年 | 14篇 |
1998年 | 2篇 |
1996年 | 4篇 |
1995年 | 5篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 13篇 |
1989年 | 13篇 |
1988年 | 13篇 |
1987年 | 9篇 |
1986年 | 13篇 |
1985年 | 11篇 |
1984年 | 10篇 |
1983年 | 4篇 |
1979年 | 2篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1972年 | 2篇 |
1971年 | 6篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 2篇 |
1961年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有653条查询结果,搜索用时 31 毫秒
31.
32.
Ayaka Oshima Wakana Mine Mitsuhiko Nakada 《Bioscience, biotechnology, and biochemistry》2016,80(11):2077-2079
High-performance liquid chromatography analysis is used to examine the distribution of isoflavones in different parts of soybean sprouts. Between the seed leaf and hypocotyl, the ratio of isoflavones differs depending on the aglycone type. Glycitein exists predominantly in the hypocotyl. Three compounds isolated from 4-day-old seed coats were identified as coumestrol and its glycosides. 相似文献
33.
Role of MAPK phosphatase-1 in the induction of monocyte chemoattractant protein-1 during the course of adipocyte hypertrophy 总被引:2,自引:0,他引:2
Ito A Suganami T Miyamoto Y Yoshimasa Y Takeya M Kamei Y Ogawa Y 《The Journal of biological chemistry》2007,282(35):25445-25452
Monocyte chemoattractant protein-1 (MCP-1), an important chemokine whose expression is increased during the course of obesity, plays a role in macrophage infiltration into obese adipose tissue. This study was designed to elucidate the role of mitogen-activated protein kinase (MAPK) phosphatase-1 (MKP-1) in the induction of MCP-1 during the course of adipocyte hypertrophy. We examined the time course of MKP-1 and MCP-1 mRNA expression and extracellular signal-regulated kinase (ERK) phosphorylation in the adipose tissue from mice rendered mildly obese by a short term high fat diet. We also studied the role of MKP-1 in the induction of MCP-1 in 3T3-L1 adipocytes during the course of adipocyte hypertrophy. MCP-1 mRNA expression was increased, followed by ERK activation and down-regulation of MKP-1, an inducible dual specificity phosphatase to inactivate ERK, in the adipose tissue at the early stage of obesity induced by a short term high fat diet, when macrophages are not infiltrated. Down-regulation of MKP-1 preceded ERK activation and increased production of MCP-1 in 3T3-L1 adipocytes in vitro during the course of adipocyte hypertrophy. Adenovirus-mediated restoration of MKP-1 in hypertrophied 3T3-L1 adipocytes reduced the otherwise increased ERK phosphorylation, thereby leading to the significant reduction of MCP-1 mRNA expression. This study provides evidence that the down-regulation of MKP-1 is critical for increased production of MCP-1 during the course of adipocyte hypertrophy. 相似文献
34.
Yamazaki Y Hozumi Y Kaneko K Sugihara T Fujii S Goto K Kato H 《Neuron glia biology》2007,3(4):325-334
Like neurons and astrocytes, oligodendrocytes have a variety of neurotransmitter receptors and ion channels. However, except for facilitating the rapid conduction of action potentials by forming myelin and buffering extracellular K(+), little is known about the direct involvement of oligodendrocytes in neuronal activities. To investigate their physiological roles, we focused on oligodendrocytes in the alveus of the rat hippocampal CA1 region. These cells were found to respond to exogenously applied glutamate by depolarization through N-methyl-D-aspartate (NMDA) receptors and non-NMDA receptors. Electrical stimulation of the border between the alveus and stratum oriens evoked inward currents through several routes involving glutamate receptors and inward rectifier K(+) channels. Moreover, electrical stimulation resembling in vivo activity evoked long-lasting depolarization. To examine the modulatory effects of oligodendrocytes on neuronal activities, we performed dual, whole-cell recording on CA1 pyramidal neurons and oligodendrocytes. Direct depolarization of oligodendrocytes shortened the latencies of action potentials evoked by antidromic stimulation. These results indicate that oligodendrocytes increase the conduction velocity of action potentials by a mechanism additional to saltatory conduction, and that they have active roles in information processing in the brain. 相似文献
35.
Ayaka Hieno Mingzhu Li Auliana Afandi Kayoko Otsubo Haruhisa Suga Koji Kageyama 《Journal of Phytopathology》2019,167(3):174-184
Phytophthora nicotianae is a phytopathogenic oomycete with a wide host range and worldwide distribution. Rapid detection and diagnosis at the early stages of disease development are important for the effective control of P. nicotianae. In this study, we designed a simple and rapid loop‐mediated isothermal amplification (LAMP)‐based detection method for P. nicotianae. We tested three DNA extraction methods and selected the Kaneka Easy DNA Extraction Kit version 2, which is rapid and robust for LAMP‐based detection. The designed primers were tested using mycelial DNA from 35 species (81 isolates) of Phytophthora, 12 species (12 isolates) of Pythium, one isolate of Phytopythium and one isolate each from seven other soil‐borne pathogens. All of the 42 P. nicotianae isolates were detected by these primers, and no other isolates gave positive results. Three isolates were tested for the sensitivity of the reaction, and the lowest amounts of template DNA that could be detected were 10 fg for two isolates and 1 fg for the third. The target was detected within 25 min in all tested samples, including DNA extracted from both inoculated and naturally infected plants. In contrast, PCR assays with P. nicotianae‐specific primers failed or showed weakened detection in several samples. Thus, we found that the rapid DNA extraction and LAMP assay methods developed in this study can be used to detect P. nicotianae with high sensitivity, specificity and stability. 相似文献
36.
Kaori Tsutsumi Ayaka Chiba Yuta Tadaki Shima Minaki Takahito Ooshima Haruka Takahashi 《Current issues in molecular biology》2021,43(3):1203
Non-small cell lung cancer (NSCLC) is an aggressive lung cancer accounting for approximately 85% of all lung cancer patients. For the patients with Stages IIIA, IIIB, and IIIC, the 5-year survival is low though with the combination with radiotherapy and chemotherapy. In addition, the occurrence of tumor cells (repopulated tumors) that survive irradiation remains a challenge. In our previous report, we subcloned the radiation-surviving tumor cells (IR cells) using the human NSCLC cell line, H1299, and found that the expression of neuropilin-1 (NRP-1) was upregulated in IR cells by the microarray analysis. Here, we investigated the contribution of neuropilin-1 to changes in the characteristics of IR cells. Although there were no differences in angiogenic activity in the tube formation assay between parental and IR cells, the cell motility was increased in IR cells compared to parental cells in the cell migration assay. This enhanced cell motility was suppressed by pretreatment with anti-NRP-1 antibody. Although further studies are necessary to identify other molecules associated with NRP-1, the increase in cellular motility in IR cells might be due to the contribution of NRP-1. Inhibition of NRP-1 would help control tumor malignancy in radiation-surviving NSCLC. 相似文献
37.
1. A hemorrhagic factor was isolated from Vipera a. aspis venom by gel filtration, ion-exchange chromatography and affinity chromatography. 2. Molecular weight of the purified factor was determined to be 67,000 Da, which was composed of 552 amino acid residues. 3. The minimum hemorrhagic dose (MHD) was measured to be 0.11 micrograms per mouse with subcutaneous injection. The hemorrhagic activity was inhibited by chelating agents and reductant. 4. The hemorrhagic factor possesses proteolytic activity against dimethylcasein. 5. Serum creatine phosphokinase level was rapidly increased within 30 min following injections of this preparation into the mice thighs. 6. Actin, one of the main components of muscle fiber, is apparently digested by the hemorrhagic factor. The pathological findings are further reported in this paper. 相似文献
38.
1. A kallikrein-like enzyme was isolated and characterized from the venom of Crotalus ruber ruber (red rattlesnake). 2. The kallikrein-like enzyme was shown to be homogeneous as demonstrated by a single band on acrylamide gel electrophoresis, isoelectric focusing, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, immunodiffusion and reverse-phase (RP) HPLC. 3. The enzyme has a molecular weight of 31,000 and isoelectric point of 4.6. It consists of 271 total amino acid residues, 24% of which are acidic amino acids. 4. Specific esterolytic activities of the kallikrein-like enzyme on N-tosyl-L-arginine methylester (TAME) and N-benzoyl-L-arginine ethylester (BAEE) are 109.5 and 23.6 mumol/min/mg, respectively. 5. The enzyme differs from trypsin as the soybean trypsin inhibitor does not inhibit the enzyme's action. Diisopropylfluorophosphate (DFP) inhibits the enzyme, suggesting that the serine hydroxyl group is important for enzyme activity. 6. The enzyme is not lethal at 15 micrograms/g in mice and has no hemorrhagic activity, yet the injection of the purified enzyme intradermally, produced capillary permeability-increasing activity as shown by the use of Evans blue dye, and immediate drop in blood pressure. It also contracted the rat uterus. 相似文献
39.
1. A hemorrhagic protease I (HP-I) was isolated from Calloselasma rhodostoma venom by Sephadex G-75, DEAE-Sephacel and Q-Sepharose column chromatographies. 2. Homogeneity was established by the formation of a single band in acrylamide gel electrophoresis. 3. HP-I has a molecular weight of 34,800 and possesses hemorrhagic and proteolytic activities. Both activities are inhibited by ethylenediaminetetraacetic acid (EDTA), 1,10-phenanthroline, ethyleneglycolbis-(beta-aminoethyl ether) N,N'-tetraacetic acid (EGTA), and tetraethylenepentamine (TEP). However neither soybean trypsin inhibitor nor p-chlorobenzoic acid (PCMB) were found to have any effect. 4. The toxin contains 311 amino acid residues and exhibits an isoelectric point of 4.5. 5. The A alpha chain of fibrinogen was cleaved first, followed later by the B beta chain. 相似文献
40.
Nakano M Tabata S Sugihara K Kouzuma Y Kimura M Yamasaki N 《Biochimica et biophysica acta》1999,1435(1-2):167-176
CEL-III, a galactose/N-acetylgalactosamine (Gal/GalNAc) specific lectin purified from a marine invertebrate Cucumaria echinata has a strong hemolytic activity especially toward human and rabbit erythrocytes. We determined the primary structure of the CEL-III by examining the amino acid sequences of the protein and the nucleotide sequence of the cDNA. The cDNA encoding CEL-III has 1823 nucleotides and an open reading frame of 1296 nucleotides. CEL-III is composed of 432 amino acid residues with a M(r) of 47? omitted?457 and has six internal tandem repeats, each with of 40-50 amino acids, comprising the N-terminal two-thirds of the molecule. Similar repeats are found in the B-chains of cytotoxic plant lectins, such as ricin and abrin, where six repetitive sequences extend throughout the molecules. A hydropathy plot predicts hydrophobic segments in the C-terminal region of CEL-III. These findings suggest that the N-terminal region of CEL-III plays an important role in binding to carbohydrate receptors on the target cell membranes, an event which triggers an intermolecular hydrophobic interaction of the C-terminal region, the result being oligomerization of CEL-III to lead to pore-formation in erythrocyte membrane. 相似文献