全文获取类型
收费全文 | 2898篇 |
免费 | 150篇 |
国内免费 | 1篇 |
出版年
2024年 | 2篇 |
2023年 | 4篇 |
2022年 | 10篇 |
2021年 | 42篇 |
2020年 | 15篇 |
2019年 | 27篇 |
2018年 | 50篇 |
2017年 | 42篇 |
2016年 | 62篇 |
2015年 | 119篇 |
2014年 | 128篇 |
2013年 | 165篇 |
2012年 | 201篇 |
2011年 | 192篇 |
2010年 | 132篇 |
2009年 | 136篇 |
2008年 | 194篇 |
2007年 | 191篇 |
2006年 | 163篇 |
2005年 | 184篇 |
2004年 | 178篇 |
2003年 | 165篇 |
2002年 | 131篇 |
2001年 | 56篇 |
2000年 | 47篇 |
1999年 | 45篇 |
1998年 | 37篇 |
1997年 | 31篇 |
1996年 | 27篇 |
1995年 | 21篇 |
1994年 | 16篇 |
1993年 | 14篇 |
1992年 | 38篇 |
1991年 | 21篇 |
1990年 | 15篇 |
1989年 | 16篇 |
1988年 | 18篇 |
1987年 | 24篇 |
1986年 | 16篇 |
1985年 | 9篇 |
1984年 | 10篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1975年 | 7篇 |
1974年 | 7篇 |
排序方式: 共有3049条查询结果,搜索用时 265 毫秒
41.
Immunohistochemical localization of nerve growth factor and epidermal growth factor in guinea pig prostate gland 总被引:1,自引:0,他引:1
Prostate glands of adult guinea pigs were stained for nerve growth factor (NGF) and epidermal growth factor (EGF) by immunohistochemical methods. Both NGF and EGF were localized diffusely in the cytoplasm of the glandular epithelial cells, and also in their secretory products. These findings suggest that NGF and EGF are synthesized, stored, and secreted by the glandular epithelial cells of the prostate. 相似文献
42.
T. Kudoh K. Kikuchi F. Nakamura S. Yokoyama K. Karube S. Tsugawa R. Minami T. Nakao 《Human genetics》1978,44(3):287-293
Summary A prenatal diagnosis of GM1-gangliosidosis was made in a pregnancy at risk, on the basis of a deficiency of -galactosidase activity demonstrated in cultured aminiotic fluid cells. Biochemical analyses were performed in the aborted fetus. GM1-ganglioside -galactosidase activity was reduced to 1% of the control value in both the brain and liver of the affected fetus. Lamellar bodies suggestive of membranous cytoplasmic bodies were found in cells of basal ganglions, while the accumulation of GM1-ganglioside in the brain was not remarkable. 相似文献
43.
Thin sections of the spore of Bacillus thiaminolyticus Matsukawa and Misawa show a characteristic surface structure with five ridges, and a series of three district layers. The outer layer of the spore coat was peeled off by SDS sonic treatment, and than the middle layer was solubilized by alkali extraction of the SDS sonic-treated spore. The spores subjected to these treatments were still refractile, heat resistant, and contained dipicolinic acid, but lost their resistance to mechanical shock. 相似文献
44.
Myocutaneous flaps based on the gluteus maximus muscle, and its blood supply, have many advantages for the surgical repair of pressure sores in paraplegics. These are described, as well as the techniques used in various areas. 相似文献
45.
46.
Yamazaki Y Hosono K Matsuda H Minami N Asai M Nakanishi H 《Biotechnology and bioengineering》1991,38(10):1218-1222
Twelve species of optically active metallocene derivatives having a 4-nitrophenyl group were prepared with horse liver alcohol dehydrogenase- or lipase-catalyzed optical resolution as the key step. The second harmonic generation (SHG) efficiently of these products was measured by the power method using the fundamental light from the Nd:YAG laser. (-)-1- (4-Nitrophenylthio)ethylferrocene (9), (+)-1-(4-nitrophenylthio)ethylruthenocene (16), (+)-1-(4-nitrophenylthio)ethylosmocene (19), (+) -1-(5-nitro-2-pyridylthio)ethylruthenocene (21), and (+) -1-[(4-nitrophenylhydrazono)methyl] -2-methylferrocene (12) showed SHG signals. The highest SHG efficiency was found with (+) -16, being 27 times more intense than the commonly used urea standard. 相似文献
47.
H Tokumitsu A Mizutani H Minami R Kobayashi H Hidaka 《The Journal of biological chemistry》1992,267(13):8919-8924
A calcyclin-associated protein with an apparent molecular weight of 50,000 (CAP-50) was purified from rabbit lung. The procedure included ammonium sulfate precipitation, anion and cation ion-exchange, and calcyclin affinity chromatographies. Interestingly, partial amino acid sequences of lysyl-endpeptidase-digested fragments indicated that CAP-50 was a member of the Ca2+/phospholipid-binding proteins, the annexin family. The sequence of a proteolytic peptide with Staphylococcus aureus V8 protease on NH2-terminal region is not homologous with any other annexin family proteins. Phospholipid binding studies showed that CAP-50 bound to phosphatidylserine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid-containing vesicles, in a Ca(2+)-dependent manner. In the presence of Ca2+/calcyclin, CAP-50 formed a complex with calcyclin and bound to the PS-containing vesicles. The apparent Kd value of calcyclin for CAP-50 was calculated to be 1.61 x 10(-6) M. Zero-length cross-linking studies indicated that 1 mol of CAP-50 bound to an equimolar unit of calcyclin. CAP-50 inhibited the phospholipase A2 activity, dose-dependently (IC50 = 0.2 microM), however, calcyclin did not alter the inhibitory effect. With the 125I-calcyclin gel overlay method, calcyclin bound tightly to CAP-50 in a Ca(2+)-dependent manner after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These results suggest that rabbit lung CAP-50 is a newly identified member of the annexin family. Ca2+/calcyclin apparently regulates the function of CAP-50 on cytosolic face of the plasma membrane. 相似文献
48.
Noriyuki Nakayama Issay Narumi Shinya Nakamoto Hiroshi Kihara 《Biotechnology letters》1992,14(8):649-652
Summary A new shuttle vector was constructed by inserting a 3.1 kbp-DNA fragment from thermophilicBacillus sp. plasmid pIH41 intoEscherichia coli plasmid pUC18. The resultant hybrid replicates in bothE. coli andB. stearothermophilus. This vector has ten unique restriction sites within a part oflacZ gene. Insertion of foreign DNA into these sites can be readily detected by a coloration method. 相似文献
49.
Growth of the hydrocarbon-rich microalga Botryococcus braunii in secondarily treated sewage 总被引:6,自引:0,他引:6
Shigeki Sawayama Tomoaki Minowa Yutaka Dote Shinya Yokoyama 《Applied microbiology and biotechnology》1992,38(1):135-138
Summary A hydrocarbon-rich green microalga, Botryococcus braunii, was able to grow well in secondarily treated sewage (STS) from domestic waste-water in a batch system. The growth in STS from domestic waste-water was as good as in the common artificial medium of modified Chu 13 and its hydrocarbon contents were high enough at 53% and 40% compared with 58% in the case of the modified Chu 13 medium. B. braunii utilized nitrate from 7.67 or 4.48 mg/l to a level below detection of < 0.01 mg/l in STS. After this consumption of nitrate, nitrite was consumed, and ammonium was not. Phosphate, even at an extremely low concentration, was also consumed by B. braunii. These results show the possibility of using STS as a medium to grow B. braunii and for removal of nitrogen and phosphorus by algal consumption in STS.Correspondence to: S. Yokoyama 相似文献
50.
Cholera enterotoxin production in Vibrio cholerae O1 strains isolated from the environment and from humans in Japan. 总被引:7,自引:2,他引:5 下载免费PDF全文
A Minami S Hashimoto H Abe M Arita T Taniguchi T Honda T Miwatani M Nishibuchi 《Applied microbiology》1991,57(8):2152-2157
Vibrio cholerae O1 strains isolated from various sources in Japan over the years 1977 through 1987 were examined to confirm the presence or absence of the cholera enterotoxin (CT) gene and production of CT and to determine the kappa-phage type. The CT gene was detected in none of 225 isolates from natural waters but was present in all of the 10 isolates from environmental waters implicated in domestic cholera cases, in 64 strains (26.6%) of the 241 isolates from imported seafoods, in 43 strains (95.6%) of the 45 isolates from domestic cholera cases, and in 119 strains (93.7%) of the 127 isolates from imported cholera cases. The results suggest that the CT gene-positive strains of V. cholerae O1 have been imported into Japan through seafoods and/or by travelers. Sporadic cholera cases have resulted in contamination of the surrounding environment, but the CT gene-positive strains may not have persisted in natural waters to serve as a reservoir for epidemic cholera. The commercially available VET-RPLA kit (a latex agglutination kit for immunological detection of CT) detected production of CT in all of the CT gene-positive strains, indicating that there was no silent CT gene in the test strains. There was a strong correlation between the kappa-phage type and the presence or absence of the CT gene, suggesting a significant clonal difference between CT gene-positive and -negative strains. Five CT gene-negative strains isolated from imported cholera cases (travelers with mild diarrhea) induced a considerable amount of fluid accumulation in rabbit and/or suckling mouse intestines, indicating production of an enterotoxic factor(s) other than CT.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献