全文获取类型
收费全文 | 394篇 |
免费 | 20篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 6篇 |
2014年 | 10篇 |
2013年 | 24篇 |
2012年 | 18篇 |
2011年 | 21篇 |
2010年 | 14篇 |
2009年 | 12篇 |
2008年 | 13篇 |
2007年 | 17篇 |
2006年 | 14篇 |
2005年 | 13篇 |
2004年 | 17篇 |
2003年 | 15篇 |
2002年 | 11篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 13篇 |
1998年 | 12篇 |
1997年 | 5篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 18篇 |
1991年 | 14篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 6篇 |
1984年 | 9篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有414条查询结果,搜索用时 15 毫秒
111.
Koichi Koshimizu Hajime Ohigashi Michael A. Huffman Toshisada Nishida Hiroyuki Takasaki 《International journal of primatology》1993,14(2):345-356
Potential medicinal plants for wild chimpanzees have been studied in order to discover their physiologically active compounds. Tests of the physiological activity of 3 plant species—Vernonia amygdalina, Aspilia mossambicensis, andFicus exasperata—indicate that they contain a variety of active compounds. From one species,V. amygdalina, an antitumor agent and 2 possible antitumor promoters are identified. Furthermore, steroid glucosides were isolated as the bitter substances. These structurally new compounds are expected to exhibit a number of significant physiological activities. The chemical investigation of possible medicinal plants used by chimpanzees should be helpful in recovering naturally occurring compounds of medicinal significance for human use. 相似文献
112.
S. Hayashi K. Matsumoto Y. Wada Y. Takasaki K. Imada 《Letters in applied microbiology》1993,17(2):75-77
A crude extract from Aureobasidium had β-glucosidase activity, hydrolysing cello-biose, methyl-β-D-glucoside, lactose, carboxymethylcellulose, avicel, o -nitrophenyl-β-D-glucoside and p -nitrophenyl-β-D-glucoside, and had favourable properties such as high pH and thermal stabilities. The optimum pH and temperature of the cello-biase activity were 4 and 80°C, respectively. The cellobiase activity was stable at pH 3–7 to 7.8 for at least 3 h, and retained 34 and 78% of its original activity at pH 1.5 and 9, respectively. Cellobiase activity was stable at 80°C for 15 min, and retained 81% of its original activity at 85°C. 相似文献
113.
Osamu Takenaka Sakie Kawamoto Toshifumi Udono Minori Arakawa Hiroyuki Takasaki Akiko Takenaka 《Primates; journal of primatology》1993,34(3):357-363
Previously designed primers for the polymerase chain reaction (PCR) amplifying microsatellite DNA segments containing GT/AC
dinucleotide repeats in the chimpanzee (Pan troglodytes) genome were used for paternity testing in a breeding colony in captivity. Combinations of three PCR primers identified the
fathers of all the tested 40 chimpanzees born in an eight-year period. The results suggested: (1) a positive (though not conclusive)
correlation between male rank and number of offspring; (2) choice of mating partners by the female rather than by the male;
and (3) absence of stable mating pairs over the years. For studies of chimpanzees in captivity and in the wild, these primers
should be useful for paternity testing, for investigating genetic variations, and for improving genetic maintenance of breeding
colonies. 相似文献
114.
S Takasaki K Yamashita K Suzuki S Iwanaga A Kobata 《The Journal of biological chemistry》1979,254(17):8548-8553
Cold-insoluble globulin isolated from bovine plasma contains six asparagine-linked sugar chains in 1 molecule (a dimeric form). These sugar chains were released from the polypeptide backbone by hydrazinolysis and labeled by reduction with NaB[3H]4. Most of these sugar chains contain N-acetylneuraminic acid and can be separated by paper electrophoresis. By combination of sequential exoglycosidase digestion and methylation study, their structures were elucidated as Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc, NeuAc alpha 2 leads to 6 or 4Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6(NeuAc alpha 2 leads to 4 or 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 3)Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc, NeuAc alpha 2 leads to 6Gal beta 1 leads to 4GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 4Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]-Man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc and NeuAc alpha 2 leads to 4Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 6[NeuAc alpha 2 leads to 4Gal beta 1 leads to 3(NeuAc alpha 2 leads to 6)GlcNAc beta 1 leads to 2Man alpha 1 leads to 3]man beta 1 leads to 4GlcNAc beta 1 leads to 4GlcNAc. 相似文献
115.
116.
Yamaji S Suzuki A Kanamori H Mishima W Yoshimi R Takasaki H Takabayashi M Fujimaki K Fujisawa S Ohno S Ishigatsubo Y 《The Journal of cell biology》2004,165(4):539-551
The linking of integrin to cytoskeleton is a critical event for an effective cell migration. Previously, we have reported that a novel integrin-linked kinase (ILK)-binding protein, affixin, is closely involved in the linkage between integrin and cytoskeleton in combination with ILK. In the present work, we demonstrated that the second calponin homology domain of affixin directly interacts with alpha-actinin in an ILK kinase activity-dependent manner, suggesting that integrin-ILK signaling evoked by substrate adhesion induces affixin-alpha-actinin interaction. The overexpression of a peptide corresponding to the alpha-actinin-binding site of affixin as well as the knockdown of endogenous affixin by small interference RNA resulted in the blockade of cell spreading. Time-lapse observation revealed that in both experiments cells were round with small peripheral blebs and failed to develop lamellipodia, suggesting that the ILK-affixin complex serves as an integrin-anchoring site for alpha-actinin and thereby mediates integrin signaling to alpha-actinin, which has been shown to play a critical role in actin polymerization at focal adhesions. 相似文献
117.
The intracellular level of taurine is maintained both by the taurine transporter (TAUT) and by endogenous synthesis from Met and Cys. We investigated in the present study the regulation of TAUT and of cysteine dioxygenase (CDO), one of the major taurine biosynthetic enzymes, in 3T3-L1 adipocytes. The TAUT activity, expression of TAUT and CDO mRNA were up-regulated by hypertonicity. In contrast, the TAUT activity, expression of TAUT and CDO mRNA were down-regulated by taurine-rich conditions. Furthermore, it was indicated that the up-regulation of TAUT activity resulted from the increased number of expressed TAUT, and not by the change in affinity of TAUT. On the other hand, the taurine-induced down-regulation of TAUT activity resulted not only from a decrease in the number of expressed TAUT but also from a decrease in their affinity. These results suggest that murine TAUT and CDO were cooperatively regulated in response to hypertonicity and taurine-rich conditions. 相似文献
118.
Lysophosphatidylcholine enhances glucose-dependent insulin secretion via an orphan G-protein-coupled receptor 总被引:4,自引:0,他引:4
Soga T Ohishi T Matsui T Saito T Matsumoto M Takasaki J Matsumoto S Kamohara M Hiyama H Yoshida S Momose K Ueda Y Matsushime H Kobori M Furuichi K 《Biochemical and biophysical research communications》2005,326(4):744-751
A lysophospholipid series, such as lysophosphatidic acid, lysophosphatidylserine, and lysophosphatidylcholine (LPC), is a bioactive lipid mediator with diverse physiological and pathological functions. LPC has been reported to induce insulin secretion from pancreatic beta-cells, however, the precise mechanism has remained elusive to date. Here we show that an orphan G-protein-coupled receptor GPR119 plays a pivotal role in this event. LPC potently enhances insulin secretion in response to high concentrations of glucose in the perfused rat pancreas via stimulation of adenylate cyclase, and dose-dependently induces intracellular cAMP accumulation and insulin secretion in a mouse pancreatic beta-cell line, NIT-1 cells. The Gs-protein-coupled receptor for LPC was identified as GPR119, which is predominantly expressed in the pancreas. GPR119-specific siRNA significantly blocked LPC-induced insulin secretion from NIT-1 cells. Our findings suggest that GPR119, which is a novel endogenous receptor for LPC, is involved in insulin secretion from beta-cells, and is a potential target for anti-diabetic drug development. 相似文献
119.
120.
Osada A Kiyozumi D Tsutsui K Ono Y Weber CN Sugimoto N Imai T Okada A Sekiguchi K 《Experimental cell research》2005,303(1):148-159
We screened for genes specifically expressed in the mesenchymes of developing hair follicles using representational differential analysis; one gene identified was MAEG, which encodes a protein consisting of five EGF-like repeats, a linker segment containing a cell-adhesive Arg-Gly-Asp (RGD) motif, and a MAM domain. Immunohistochemistry showed that MAEG protein was localized at the basement membrane of embryonic skin and developing hair follicles, while MAEG expression diminished at the tip of the hair bud. A recombinant MAEG fragment containing the RGD motif was active in mediating adhesion of keratinocytes to the substratum in an RGD-dependent manner. One of the adhesion receptors recognizing the RGD motif was found to be the alpha8beta1 integrin, the expression of which was detected in the placode close to MAEG-positive mesenchymal cells, but later became restricted to the tip of the developing hair bud. Given its localized expression at the basement membrane in developing hair follicles and the RGD-dependent cell-adhesive activity, MAEG may play a role as a mediator regulating epithelial-mesenchymal interaction through binding to RGD-binding integrins including alpha8beta1 during hair follicle development. 相似文献