全文获取类型
收费全文 | 3791篇 |
免费 | 324篇 |
国内免费 | 2篇 |
出版年
2023年 | 23篇 |
2022年 | 34篇 |
2021年 | 61篇 |
2020年 | 52篇 |
2019年 | 59篇 |
2018年 | 64篇 |
2017年 | 82篇 |
2016年 | 123篇 |
2015年 | 175篇 |
2014年 | 217篇 |
2013年 | 246篇 |
2012年 | 322篇 |
2011年 | 285篇 |
2010年 | 211篇 |
2009年 | 163篇 |
2008年 | 219篇 |
2007年 | 242篇 |
2006年 | 193篇 |
2005年 | 192篇 |
2004年 | 174篇 |
2003年 | 149篇 |
2002年 | 172篇 |
2001年 | 45篇 |
2000年 | 44篇 |
1999年 | 48篇 |
1998年 | 44篇 |
1997年 | 31篇 |
1996年 | 40篇 |
1995年 | 29篇 |
1994年 | 30篇 |
1993年 | 22篇 |
1992年 | 17篇 |
1991年 | 25篇 |
1990年 | 24篇 |
1989年 | 26篇 |
1988年 | 28篇 |
1987年 | 12篇 |
1986年 | 12篇 |
1985年 | 15篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 12篇 |
1981年 | 13篇 |
1980年 | 9篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 11篇 |
1974年 | 6篇 |
1973年 | 12篇 |
排序方式: 共有4117条查询结果,搜索用时 265 毫秒
61.
62.
Pascal Bonnarme Michel Delattre Georges Corrieu Marcel Asther 《Applied microbiology and biotechnology》1992,37(5):670-673
Summary Lignin (LiP) and manganese peroxidase (MnP) excretion by Phanerochaete chrysosporium INA-12 was significantly increased in response to fungal extract supplementation. LiP and MnP production was increased 1.7- and 1.8-fold, respectively, with fungal extracts from agitated pellet cultures of strain INA-12, namely fungal extracts P6 and P4. In cultures supplemented with a fungal extract harvested from static cultures of strain INA-12 (fungal extract S4), LiP and MnP production was increased 1.8- and 1.6-fold, respectively. Succinate dehydrogenase activity, a mitochondrial marker, was significantly enhanced (2.7-fold) in cultures with the addition of fungal extracts.
Correspondence to: M. Asther 相似文献
63.
A long-range restriction map of the human chromosome 19q13 region: Close physical linkage between CKMM and the ERCC1 and ERCC2 genes 总被引:12,自引:4,他引:8 下载免费PDF全文
64.
Monoclonal antibodies against human low density lipoprotein. Stoichiometric binding studies using Fab fragments 总被引:1,自引:0,他引:1
Because of its physical properties, apolipoprotein B (apo B) has remained poorly characterized. In an attempt to elucidate apo B structure, the Fab fragments of 3 different monoclonal anti-human apo B antibodies were tested in a quantitative assay for their binding to human low density lipoprotein (LDL). In each case the assay gave a linear Scatchard plot with a maximum of 1 Fab fragment bound to a single LDL particle. This result favors an LDL model containing a single large Mr apo B protein, which is not composed of multiple, identical, small Mr subunits. 相似文献
65.
Dagmar Jičínská Eduard Brabec Marcel Rejmánek Jan Jeník Joří Haager Josef Holub Věroslav Samek Hana Rambousková Josef Holub Marie Naděžda Končalová Robert Neuhäusl Josev Kyncl František Krahuleo Jaroslav Dobrý Blanka Úlehlová Jiří Úlehla Eliška Rybníčková Kamil Rybníček 《Folia Geobotanica》1982,17(4):431-448
66.
Different methods for the preparation of active lipoxygenase (LOX) extracts from apples were compared. Highest activities were obtained using a 0.25 M phosphate buffer (pH 7) containing 1% Triton X-100 and 10?2 M metabisulphite as extraction solvent. LOX activity during storage was investigated in the core, flesh, and peel. Activity was always highest in the core and peel. On storage, activity was increased in each part of the fruit but especially in the core and peel. Increase in LOX preceded the browning of the core. LOX may be responsible for the browning and may be concerned in the induction of superficial scald. 相似文献
67.
68.
A method is described for purification of MSV-MuLV from culture supernatant of chronically infected 78A1 rat embryo cell line. This method involves direct polyethylene glycol-NaCl precipitation of the low speed supernatant of culture fluid followed by digestion of the pellet with trypsin. This procedure efficiently disrupts large aggregates which normally entrap most of the virus. Highly purified virus can be obtained in very good yield by a combination of sedimentation velocity and isopycnic centrifugation : yields up to 100 A280 units (17 mg of protein) of purified virus per liter of culture fluid can be observed. This procedure appears well suited for large scale isolation of virion associated enzymatic activities. 相似文献
69.
70.
In the immature rat uterus, high concentrations of androgens competed specifically with estradiol on the estrogen receptor (RE). This competition was stereospecific for C19 steroids bearing a 17β and/or 3 hydroxyl group. Very low affinity ligands, such as testosterone, could not compete with estradiol at equilibrium but decreased the association rate of estradiol on its receptor. High doses (> 0.4mg) of 5 α aihydrotestosterone provoked as the nuclear translocation of RE. The nuclear receptor thus formed displayed the same 5.2 S sedimentation constant as that induced by estradiol. We conclude that the weak affinity binding of androgens to the estrogen receptor is sufficient to induce its nuclear translocation provided androgen concentration is high enough in uterus to occupy the estradiol binding site. Conversely, progesterone which does not bind RE could not provoke its nuclear translocation. 相似文献