全文获取类型
收费全文 | 1425篇 |
免费 | 75篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 18篇 |
2018年 | 17篇 |
2017年 | 25篇 |
2016年 | 28篇 |
2015年 | 42篇 |
2014年 | 61篇 |
2013年 | 78篇 |
2012年 | 79篇 |
2011年 | 101篇 |
2010年 | 68篇 |
2009年 | 55篇 |
2008年 | 88篇 |
2007年 | 99篇 |
2006年 | 94篇 |
2005年 | 76篇 |
2004年 | 104篇 |
2003年 | 103篇 |
2002年 | 98篇 |
2001年 | 9篇 |
2000年 | 8篇 |
1999年 | 25篇 |
1998年 | 26篇 |
1997年 | 12篇 |
1996年 | 18篇 |
1995年 | 8篇 |
1994年 | 17篇 |
1993年 | 11篇 |
1992年 | 12篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有1500条查询结果,搜索用时 31 毫秒
11.
Kaoru Miyazaki Keisuke Mashima Nobuhiko Yamashita Jinpei Yamashita Takekazu Horio 《In vitro cellular & developmental biology. Plant》1985,21(1):62-66
Summary We have previously reported the transformation by Rous sarcoma virus of a cloned epithelial cell line (BRL) established from
Buffalo rat liver by H. Coon. The nontransformed (BRL) and transformed (RSV-BRL) cells grew at comparable rates in culture,
whereas only the transformed cells were tumorigenic in vivo. We report here on the existence in rat and mouse sera of a growth
inhibitor for the nontransformed BRL cells. The transformed BRL cells (RSV-BRL) were insensitive to this inhibitor. The inhibitory
activity was not prominent in sera from other species of animals tested except for rabbit; this serum inhibited the growth
of RSV-BRL cells more strongly than that of BRL cells. The growth inhibitor was partially purified from rat serum. It is a
protein free of lipid and has a molecular weight of about 220 000. The inhibitor could be separated into three components
of pI 4.6, 5.2 (major) and 5.6 by isoelectric electrophoresis.
EDITOR'S STATEMENT Although compelling theoretical arguments sometimes can be made for the likely existence of growth-inhibitory
substances of physical relevance in the control of cell proliferation, experiments aimed at identifying and studying such
factors often are difficult to design and interpret, and little strong data exists to suggest that growth-inhibitory substances
are important regulatorsin vivo. The information presented in this paper represents a start toward developing a useful system for studying growth-inhibitory
factor. David W. Barnes 相似文献
12.
Kaoru Hatanaka Masami Imakita Soei Go Akira Yamamoto M.D. 《Cell and tissue research》1986,246(1):53-56
Summary A mast-cell activator, compound 48/80, causes proliferation of mesenchymal cells in the mesentery of rats. Its effect on W/W
vmice deficient in mast cells was tested to determine whether the proliferation is mediated in the degranulation of mast cells. Incorporation of [3H]thymidine into mesenchymal cells in the mesentery of these mice with or without compound 48/80 was very small compared to their normal litter mates. However, bone marrow transplantation markedly enhanced the effect of compound 48/80, and resulted in an incorporation of [3H]thymidine almost comparable to that observed in normal mice. Our results provide evidence that mesenchymal cell proliferation is caused by a product secreted by mast cells when stimulated by compound 48/80.Supported by a Grant-in-Aid for Scientific Research, No. 366, from the Japanese Ministry of Health and WelfareThe authors are indebted to Drs. Motomu Minamiyama and Yukio Hirata for valuable advices, and to Miss Mitsuko Inoue for technical assistance 相似文献
13.
Kaoru Saigo Ryu Ueda Tadashi Miyake 《Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression》1983,740(4):390-401
In a previous communication (Saigo, K., Millstein, L. and Thomas, C.A., Jr. (1981) Cold Spring Harbor Symp. Quant. Biol. 45, 815–827), the overall structure of histone genes of Schneider line 2 cells was shown to extensively differ from that of Oregon-R embryo from which the cell line was established, and it was speculated that the histone genes might be reshuffled extensively during either the periods of the establishment, or maintenance of cell lines, or both. To establish the validity of this notion the structure of histone genes was examined in Drosophila melanogaster cultured cells. The overall organization of histone gene clusters was found to be stably maintained in both the periods for the establishment and maintenance of cultured cells, indicating that the previous assumption is inadequate. Instead of an extensive rearrangement, minor structural changes were found to occasionally occur probably by simple base substitutions and/or, deletion or insertion of very short DNA pieces. It was also shown that the extensive variation in structures of histone genes in cultured cells such as Schneider line 2 are attributable to polymorphism on the level of individual flies. 相似文献
14.
Kaoru Nakamura Takehiko Miyai Kiyoko Inoue Seiji Kawasaki Shinzaburo Oka Atsuyoshi Ohno 《Biocatalysis and Biotransformation》1990,3(1):17-24
Esters of 3-methyl-2-oxobutanoic acid are reduced with bakers' yeast by three methods: free bakers' yeast in water, immobilized bakers' yeast in water, and immobilized bakers' yeast in hexane. Although (R)-hydroxy esters are obtained in all cases, the enantiomeric excess varies from 3% (reduction of the methyl ester with free bakers' yeast in water) to 93% (reduction of the butyl ester with immobilized bakers' yeast in hexane) depending on the structure of substrate and on the reaction conditions. The mechanism of the present stereochemical control is discussed. 相似文献
15.
Hidefumi Yoshioka Hideyo Ohuchi Yoshiyasu Ishimaru Tetsuya Ishikawa Tsutomu Nohno Kaoru Saigo Sumihare Noji 《Development, growth & differentiation》1996,38(6):617-624
Members of the fibroblast growth factor (FGF) family play important roles in various developmental processes in vertebrates. Since two genes closely related to the vertebrate FGF receptor (FGFR) genes DFR1 and DFR2/breathless have already been reported in Drosophila , the existence of a Drosophila FGF has been predicted. In the present study, we examined whether DFR1 is functionally interchangeable with a vertebrate FGFR in the Xenopus system. First, we found that the expression of DFR1 promoted Ca2+ efflux in response to human basic (b)FGF in Xenopus oocytes, whereas the coexpression of a dominant negative form of DFR1 (ΔDFR1) with a chick FGFR1/cek1 inhibited promotion of Ca2+ efflux induced by the expression of cek1 in the oocyte. Second, the expression of ΔDFR1 was observed to induce a defect in the posterior structure of the Xenopus embryo at stage 30, as observed with a dominant negative form of cek1 (Δcek1). Third, we found that the expression of ΔDFR1 inhibited the expression of FGF-regulated genes such as Xbra, Xnot , and Xshh in Xenopus embryos at stage 11, while the coexpression of DFR1 with ΔDFR1 could rescue the inhibited expression of FGF-regulated genes. These results indicate that DFR1 acts as an FGFR in Xenopus embryos and that an FGF is likely to exist in Drosophila . 相似文献
16.
17.
Journal of Plant Research - Silicon (Si) accumulation differs greatly among plant species, as revealed by an increasing number of studies reporting whole-leaf Si concentration for a wide range of... 相似文献
18.
Efficient production of IGG human monoclonal antibodies by lymphocytes stimulated by lipopolysaccharide,pokeweed mitogen,and interleukin 4 总被引:1,自引:0,他引:1
Kaoru Yoshinari Kenji Arai Hideki Kimura Kunio Matsumoto Yutaka Yamaguchi 《In vitro cellular & developmental biology. Animal》1996,32(6):372-377
Summary Extensive screening of the mitogens lipopolysaccharide (LPS), pokeweed mitogen (PWM), andStaphylococcus aureus Cowan I (SAC I), alone and in combination and with and without interleukin (IL) was performed forin vitro activation of regional lymph node lymphocytes from lung cancer patients for the production of human IgG, IgM, and IgA. As
assessed by electrofusion of the lymphocytes following their exposure to these agents with mouse myeloma cells and incubation
of the fused hybridoma, a remarkable stimulatory effect was shown by LPS and particularly by LPS plus IL-4, which was substantially
greater than that of either SAC I or PWM with or without various IL. Optimization studies indicated that the addition of PWM
to LPS and IL-4 in the culture medium further stimulated the human antibody (Ab) production, and that the optimal formulation
for stimulations of human IgG production was a culture medium containing 20 μg/ml of LPS, 1/500 of PWM, and 100 u/ml of IL-4. 相似文献
19.
Yamato Kikkawa Kotaro Akaogi Hiroto Mizushima Naoki Yamanaka Makoto Umeda Kaoru Miyazaki 《In vitro cellular & developmental biology. Animal》1996,32(1):46-52
Summary Ladsin is a laminin-like cell-adhesive scatter factor with potent cell motility-stimulating ability and was purified from
serum-free conditioned medium of a malignant human gastric adenocarcinoma cell line STKM-1. To test its possible role in tumor
angiogenesis, we investigated its effect on primary culture of endothelial cells (human umbilical vein endothelial cells)
and endothelial cell line ECV304 in this study. Cell adhesion and motility effects of ladsin were observed in both types of
endothelial cells. In cell-attachment assay, ladsin interacted with integrin α3β1 that was expressed on the endothelial cell
surface. In Boyden chambers, ladsin stimulated both directed and random migration of ECV304 cells. Ladsin induced repair of
artificial wounds generated in ECV304 cell monolayers by stimulating cell migration. Ladsin did not affect the growth rate
of ECV304 cells at a low cell density but significantly increased the saturation cell density. These results suggest that
ladsin may be involved in the adhesion and migration of endothelial cells under some physiological and pathological conditions. 相似文献
20.
An algal suspension containing protoplasmic detritus [termed, single cell detritus (SCD)] was prepared from freeze-dried fronds
of Ulva and its dietary value to Artemia nauplii was tested after size fractionation. The dissolved fraction (<0.22 μm) ofthe
Ulva suspension contained ca. 48% of theoriginal protein in the Ulva, but had no dietaryvalue to Artemia, which is a suspension
feeder. In contrast, the fraction passing through a 100-μm meshand containing SCD of 2–14 μm in diameter, contributedto the
survival of Artemia. The fraction remaining on the 100 μm mesh was further incubated with and without the bacterium Pseudoalteromonas
espejiana strain AR06 FERM BP-5024. The bacterium degraded
Ulva forming new SCD over 106 mL -1 level as rapidly as by 16 h of incubation. The dietary
value of Ulva for Artemia growth was elevated over four times by the incubation. The protein content of the SCD
was approximately doubled by the attaching of bacteria, suggesting the enhanced Artemia growth is attributable to
the combined effect of the SCD and the bacteria. Development of a hatchery diet from Ulva , a resource with a low
commercial value, is suggested utilizing the degrading and attaching ability of P. espejiana.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献