全文获取类型
收费全文 | 1626篇 |
免费 | 114篇 |
专业分类
1740篇 |
出版年
2022年 | 8篇 |
2021年 | 11篇 |
2020年 | 12篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 18篇 |
2015年 | 40篇 |
2014年 | 52篇 |
2013年 | 128篇 |
2012年 | 78篇 |
2011年 | 78篇 |
2010年 | 40篇 |
2009年 | 31篇 |
2008年 | 69篇 |
2007年 | 63篇 |
2006年 | 59篇 |
2005年 | 66篇 |
2004年 | 64篇 |
2003年 | 67篇 |
2002年 | 63篇 |
2001年 | 70篇 |
2000年 | 80篇 |
1999年 | 52篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 19篇 |
1995年 | 16篇 |
1993年 | 16篇 |
1992年 | 52篇 |
1991年 | 42篇 |
1990年 | 35篇 |
1989年 | 46篇 |
1988年 | 29篇 |
1987年 | 23篇 |
1986年 | 25篇 |
1985年 | 38篇 |
1984年 | 19篇 |
1983年 | 18篇 |
1982年 | 11篇 |
1981年 | 15篇 |
1980年 | 7篇 |
1979年 | 13篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 14篇 |
1974年 | 6篇 |
1973年 | 11篇 |
1966年 | 5篇 |
排序方式: 共有1740条查询结果,搜索用时 15 毫秒
81.
Kohei Oda Takanori Nakazima Takao Terashita Ken-ichiro Suzuki Sawao Murao 《Bioscience, biotechnology, and biochemistry》2013,77(11):3073-3080
A S-PI(Pepstatin Ac)-insensitive carboxyl proteinase was found in culture filtrate of a Xanthomonas sp. bacterium. The carboxyl proteinase was highly purified and about 100 mg of the enzyme was obtained from 601 of culture filtrate, with a recovery of 25%. The optimum condition for the action of the purified enzyme toward casein was approx. pH 2.7 and its activity was not inhibited by any of such carboxyl proteinase inhibitors as Pepstatin, S-PI, and DAN but EPNP inhibited it. Such behavior of the enzyme against inhibitors resembles that of Pseudomonas sp. carboxyl proteinase, the first found from a bacterium. Some differences were observed, however, in their properties such as optimum pH, isoelectric point, and amino acid composition. 相似文献
82.
Minoru Yoshida Hiroshi Morimoto Masanao Matsui Ryohei Oda 《Bioscience, biotechnology, and biochemistry》2013,77(9):1308-1313
Biological availability of 23 alcohols, 16 aldehydes and 2 ketones was compared by the mini-test with chicks. Chicks can utilize methanol and ethanol, but not the alcohols of carbon chain from 3 to 9. Lauryl and myristyl alcohols were well utilized but those of higher carbon chain than 14 were not, mainly due to low digestibility. Glycerol and D-sorbitol were well utilized but not 4 other poly alcohols tested. Aldehydes and ketones with free carbonyl group showed low availability or even toxicity, but their derivatives with masked group showed no detrimental effect. Acetaldehyde, acetal and aldehydes of carbon chain longer than 9 were partially utilized. 相似文献
83.
Minora Nakajima Junichi Oda Hiroshi Fukami 《Bioscience, biotechnology, and biochemistry》2013,77(10):695-699
Nodakenetin and marmesin were synthesized from β-resorcylaldehyde through 2-(α-hy-droxyisopropyl)-6-hydroxycoumaran. 相似文献
84.
85.
Takao Terashita Kōhei Oda Matashi Kōno Sawao Murao 《Bioscience, biotechnology, and biochemistry》2013,77(9):1937-1943
A Streptomyces-pepsin inhibitor (S-PI or Pepstatin Ac), and DAN-insensitive carboxyl proteinase was found in a still culture filtrate of Lentinus edodes. The new carboxyl proteinase was purified, and about 9 mg purified enzyme was obtained from 19 liters of culture filtrate, with 11% recovery. The enzyme showed a single band on polyacrylamide gel electrophoresis. The molecular weight and isoelectric point were 40,000 and pH 4.2, respectively. The enzyme did not contain histidine and was composed of 387 amino acid residues. The enzyme was most active between pH 2.7 ~ 2.9, and stable over a pH of 3.2 ~ 5.2 for 3 hr at 37°C. The enzyme was not inhibited by S-PI or synthetic pepsin inhibitors such as DAN and EPNP. The physicochemical and enzymological properties were very similar to those of Scytalidium lignicolum carboxyl proteinase A, which was reported to be an S-PI-, and DAN-insensitive carboxyl proteinase. 相似文献
86.
Takao Takahashi Toshiharu Yagi Toyohiro Oda Irvin E. Liener 《Bioscience, biotechnology, and biochemistry》2013,77(4):865-867
(+)-Biotin was synthesized from D-glucosamine in a sequence of 13 reactions. 相似文献
87.
88.
The cell wall of the tip‐growing cells of the giant‐cellular xanthophycean alga Vaucheria frigida is mainly composed of cellulose microfibrils (CMFs) arranged in random directions and the major matrix component into which the CMFs are embedded throughout the cell. The mechanical properties of a cell‐wall fragment isolated from the tip‐growing region, which was inflated by artificially applied pressure, were measured after enzymatic removal of the matrix component by using a protease; the results showed that the matrix component is involved in the maintenance of cell wall strength. Since glucose and uronic acid are present in the matrix component of Vaucheria cell walls, we measured the mechanical properties of the cell wall after treatment with endo‐1,3‐ß‐glucanase and observed the fine structures of its surfaces by atomic force microscopy. The major matrix component was partially removed from the cell wall by glucanase, and the enzyme treatment significantly weakened the cell wall strength without affecting the pH dependence of cell wall extensibility. The enzymatic removal of the major matrix component by using a protease released polysaccharide containing glucose and glucuronic acid. This suggests that the major matrix component of the algal cell walls contains both proteins (or polypeptides) and polysaccharides consisting of glucose and glucuronic acid as the main constituents. 相似文献
89.
T Oda Y Iijima T Sada H Nishino K Oizumi H Koike 《Biochemical and biophysical research communications》1988,152(1):456-462
We studied the effects of chronic treatment with a novel angiotensin converting enzyme inhibitor, alpha-[(2S,6R)-6-[(1S)-1-ethoxycarbonyl-3-phenylpropyl]amino-5-oxo-2- (2-thienyl)perhydro-1,4-thiazepin-4-yl]acetic acid.HCl (CS622), and a vasodilator, hydralazine, on plasma atrial natriuretic factor (ANF) levels and kidney ANF receptors in spontaneously hypertensive rats (SHR). Plasma ANF level was decreased and cardiac hypertrophy reduced in CS622 treated SHR, but not in hydralazine treated SHR, although blood pressure was lowered similarly in both SHR groups. The binding capacity of kidney ANF receptors increased and the affinity decreased in CS622 treated SHR compared to untreated SHR. These results suggest that decrease of plasma ANF results from decreased cardiac load but not from lowered blood pressure, and that changes in ANF receptors result from increased plasma ANF. 相似文献
90.
K Fukuda Y Koshihara H Oda M Ohyama T Ooyama 《Biochemical and biophysical research communications》1988,151(3):1060-1068
Type V collagen from human placenta remarkably inhibited human umbilical vein endothelial cell (HUVEC) proliferation in a dose-dependent manner when coated on the culture dishes. Other types of collagen (I, III, IV) and fibronectin enhanced HUVEC proliferation under the same conditions. The inhibitory activity of type V collagen was seen not only when it was coated on the dishes, but also when it was directly added into cell culture. The attachment effect of type V collagen did not differ from that of type I collagen. The inhibitory activity is a phenomenon selective for endothelial cells, since type V collagen did not affect the proliferation of human umbilical vein smooth muscle cells, aortic smooth muscle cells, or nasal mucosa fibroblasts. 相似文献