全文获取类型
收费全文 | 2525篇 |
免费 | 154篇 |
国内免费 | 1篇 |
出版年
2022年 | 6篇 |
2021年 | 27篇 |
2020年 | 26篇 |
2019年 | 20篇 |
2018年 | 26篇 |
2017年 | 26篇 |
2016年 | 37篇 |
2015年 | 69篇 |
2014年 | 94篇 |
2013年 | 140篇 |
2012年 | 131篇 |
2011年 | 152篇 |
2010年 | 89篇 |
2009年 | 84篇 |
2008年 | 140篇 |
2007年 | 146篇 |
2006年 | 152篇 |
2005年 | 129篇 |
2004年 | 174篇 |
2003年 | 137篇 |
2002年 | 148篇 |
2001年 | 49篇 |
2000年 | 70篇 |
1999年 | 54篇 |
1998年 | 29篇 |
1997年 | 24篇 |
1996年 | 24篇 |
1995年 | 19篇 |
1994年 | 17篇 |
1993年 | 24篇 |
1992年 | 37篇 |
1991年 | 38篇 |
1990年 | 34篇 |
1989年 | 38篇 |
1988年 | 29篇 |
1987年 | 30篇 |
1986年 | 17篇 |
1985年 | 28篇 |
1984年 | 26篇 |
1983年 | 19篇 |
1982年 | 13篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 9篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1972年 | 6篇 |
1969年 | 5篇 |
1968年 | 10篇 |
1966年 | 5篇 |
排序方式: 共有2680条查询结果,搜索用时 15 毫秒
1.
Distribution of Ankyrin Isoforms and Their Proteolysis After Ischemia and Reperfusion in Rat Brain 总被引:1,自引:0,他引:1
Kazuki Harada Shiro Fukuda †Manabu Kunimoto Ken-ichi Yoshida 《Journal of neurochemistry》1997,69(1):371-376
Abstract: The distribution of brain-type ankyrin (ankyrinB , 212 kDa) and erythrocyte-type ankyrin (ankyrinR , 239 kDa) was investigated in the subcellular fractions of rat forebrain (P1, 1,000 g pellet; P2, 15,000 g pellet; P3, 100,000 g pellet; S, 100,000 g supernatant) by immunoblotting using specific antibodies. The P2 fraction contained ∼40% of the 212- and 163-kDa isoforms of ankyrinB and the 239-kDa isoform of ankyrinR . Further subfractionation of the P2 by Percoll gradient centrifugation followed by separation of myelin showed association of the three ankyrin isoforms with the synaptosome-rich fraction but not with the myelin-rich fraction. The plasma membrane-rich P3 fraction contained a concentration of ankyrin isoforms similar to that in the P2 fraction. In vitro proteolysis of ankyrin in the P2 fraction with calpain showed that the 212-kDa ankyrinB was more susceptible to calpain than was ankyrinR . In the two-vessel occlusion model, ischemia for 30 min generated the 160-kDa fragment of ankyrinR , and reperfusion for 60 min after 30 min of ischemia remarkably increased the 160-kDa fragment. The reperfusion also significantly decreased the 212-kDa isoform of ankyrinB . Both ischemia-reperfusion and in vitro proteolysis with calpain generated the 160-kDa fragment of ankyrinR , suggesting the involvement of calpain. 相似文献
2.
3.
4.
5.
L Takemoto J Smith T Kodama 《Biochemical and biophysical research communications》1987,142(3):761-766
Polyclonal antisera to three synthetic peptides of bovine MIP26K have been used in combination with Western blot analysis to probe for changes of the MIP26K molecule during human senile cataractogenesis. Anti-MIP26K229-237 binds well to the 26K component from cataractous lens membranes, but binds poorly to the same component from normal lens. In contrast, antisera to two other sequences of MIP26K (anti-MIP26K252-259 and anti-MIP26K256-263) bind approximately equally well to the 26K component from either cataractous or normal lens. Together, these results demonstrate that during cataract development there is a selective covalent change in a region of the MIP26K molecule that may have profound effects upon the ability of this molecule to facilitate intercellular communication between lens fiber cells. 相似文献
6.
Lin Cui Kenoki Ohuchida Kazuhiro Mizumoto Taiki Moriyama Manabu Onimaru Kohei Nakata Toshinaga Nabae Takashi Ueki Norihiro Sato Yohei Tominaga Masao Tanaka 《PloS one》2010,5(8)
Although CD133 has been reported to be a promising colon cancer stem cell marker, the biological functions of CD133+ colon cancer cells remain controversial. In the present study, we investigated the biological differences between CD133+ and CD133− colon cancer cells, with a particular focus on their interactions with cancer-associated fibroblasts, especially CD10+ fibroblasts. We used 19 primary colon cancer tissues, 30 primary cultures of fibroblasts derived from colon cancer tissues and 6 colon cancer cell lines. We isolated CD133+ and CD133− subpopulations from the colon cancer tissues and cultured cells. In vitro analyses revealed that the two populations showed similar biological behaviors in their proliferation and chemosensitivity. In vivo analyses revealed that CD133+ cells showed significantly greater tumor growth than CD133− cells (P = 0.007). Moreover, in cocultures with primary fibroblasts derived from colon cancer tissues, CD133+ cells exhibited significantly more invasive behaviors than CD133− cells (P<0.001), especially in cocultures with CD10+ fibroblasts (P<0.0001). Further in vivo analyses revealed that CD10+ fibroblasts enhanced the tumor growth of CD133+ cells significantly more than CD10− fibroblasts (P<0.05). These data demonstrate that the in vitro invasive properties and in vivo tumor growth of CD133+ colon cancer cells are enhanced in the presence of specific cancer-associated fibroblasts, CD10+ fibroblasts, suggesting that the interactions between these specific cell populations have important roles in cancer progression. Therefore, these specific interactions may be promising targets for new colon cancer therapies. 相似文献
7.
A second Warburg-like effect in cancer metabolism: The metabolic shift of glutamine-derived nitrogen
Manabu Kodama Keiichi I. Nakayama 《BioEssays : news and reviews in molecular, cellular and developmental biology》2020,42(12):2000169
Carbon and nitrogen are essential elements for life. Glucose as a carbon source and glutamine as a nitrogen source are important nutrients for cell proliferation. About 100 years ago, it was discovered that cancer cells that have acquired unlimited proliferative capacity and undergone malignant evolution in their host manifest a cancer-specific remodeling of glucose metabolism (the Warburg effect). Only recently, however, was it shown that the metabolism of glutamine-derived nitrogen is substantially shifted from glutaminolysis to nucleotide biosynthesis during malignant progression of cancer—which might be referred to as a “second” Warburg effect. In this review, address the mechanism and relevance of this metabolic shift of glutamine-derived nitrogen in human cancer. We also examine the clinical potential of anticancer therapies that modulate the metabolic pathways of glutamine-derived nitrogen. This shift may be as important as the shift in carbon metabolism, which has long been known as the Warburg effect. 相似文献
8.
A new protein factor promoting aggregation of tropomyosin 总被引:6,自引:0,他引:6
9.
10.
S Kurashige Y Akuzawa T Yoshida C Teshima K Kodama S Mitsuhashi 《Microbiology and immunology》1982,26(1):87-92
ICR mice were immunized with sheep red blood cells (sRBC). Both adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP) activities in spleen lymphocytes increased faster than the serum antibody titer and reached a peak one week after the immunization. ADA activity increased significantly in T lymphocytes but not in B lymphocytes collected from the spleens of the immunized mice. A statistically significant increase in PNP activity was found in both T and B lymphocytes from the spleens of the immunized mice. Spleen lymphocytes collected from ICR mice which had been immunized with mitomycin C-treated sarcoma 180 (S180) cells one week earlier showed cytotoxic activity against viable S180 cells. Both ADA and PNP activities in spleen lymphocytes of S180-immunized mice increased significantly, and both activities increased in T lymphocytes prepared from spleen of immunized mice. In contrast, an increase was found in PNP activity but not in ADA activity in B lymphocytes. These results suggest that an increase in both ADA and PNP activities may by necessary for the T-cell response in both humoral and cellular immune responses, and that an increase in PNP activity may be necessary for the B-cell response. 相似文献