全文获取类型
收费全文 | 1046篇 |
免费 | 76篇 |
国内免费 | 1篇 |
出版年
2023年 | 13篇 |
2022年 | 22篇 |
2021年 | 38篇 |
2020年 | 40篇 |
2019年 | 42篇 |
2018年 | 45篇 |
2017年 | 42篇 |
2016年 | 55篇 |
2015年 | 40篇 |
2014年 | 62篇 |
2013年 | 77篇 |
2012年 | 65篇 |
2011年 | 64篇 |
2010年 | 43篇 |
2009年 | 37篇 |
2008年 | 35篇 |
2007年 | 44篇 |
2006年 | 26篇 |
2005年 | 25篇 |
2004年 | 36篇 |
2003年 | 33篇 |
2002年 | 25篇 |
2001年 | 16篇 |
2000年 | 15篇 |
1999年 | 7篇 |
1998年 | 6篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1992年 | 7篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 10篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 7篇 |
1984年 | 5篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1976年 | 4篇 |
1975年 | 4篇 |
1974年 | 7篇 |
1973年 | 4篇 |
1969年 | 4篇 |
1968年 | 6篇 |
1966年 | 5篇 |
排序方式: 共有1123条查询结果,搜索用时 15 毫秒
31.
32.
Mansour Alsharidah Norman R. Lazarus Tomasz E. George Chibeza C. Agley Stephen D. R. Harridge 《Aging cell》2013,12(3):333-344
The myogenic behaviour of primary human muscle precursor cells (MPCs) obtained from young (aged 20–25 years) and elderly people (aged 67–82 years) was studied in culture. Cells were compared in terms of proliferation, DNA damage, time course and extent of myogenic marker expression during differentiation, fusion, size of the formed myotubes, secretion of the myogenic regulatory cytokine TGF‐β1 and sensitivity to TGF‐β1 treatment. No differences were observed between cells obtained from the young and elderly people. The cell populations were expanded in culture until replicative senescence. Cultures that maintained their initial proportion of myogenic cells (desmin positive) with passaging (n = 5) were studied and compared with cells from the same individuals in the non‐senescent state. The senescent cells exhibited a greater number of cells with DNA damage (γ‐H2AX positive), showed impaired expression of markers of differentiation, fused less well, formed smaller myotubes and secreted more TGF‐β. The data strongly suggest that MPCs from young and elderly people have similar myogenic behaviour. 相似文献
33.
Tarek S. Mansour Haolun Jin Wei Wang Dilip M. Dixit Colleen A. Evans H. L. Allan Tse 《Nucleosides, nucleotides & nucleic acids》2013,32(3-5):627-635
Abstract 3′-Oxa-4′-thiocytidine nucleoside analogues 14–17 were prepared from oxathiolanes 10 and 11, and evaluated for activity against HIV-1 and HBV in vitro. The nucleoside analogues were found to possess potent activities against HIV-1 in a panel of cell lines. Compound 16 is moderately active against HBV in 2.2.15 cells. 相似文献
34.
Galal E. H. Elgemeie Omar A. Mansour Nadia H. Metwally 《Nucleosides, nucleotides & nucleic acids》2013,32(1):113-123
Abstract A series of different novel nonclassical nucleosides have been synthesised and evaluated for their inhibitory activity against human immunodeficiency virus (HIV) replication in MT-4 cells. 相似文献
35.
Abdel Kader Mansour Yehia A. Ibrahim Nasser S. A. M. Khalil 《Nucleosides, nucleotides & nucleic acids》2013,32(10):2265-2283
Abstract The 6-β-arylvinyl-2- and 4-glucosyl-3-thioxo-2,3-dihydro-1,2,4-triazin-5(4H)-ones were synthesized with high selectivity using the recently developed amino protecting group strategy. The structure of these new glucosides was established chemically and spectroscopically. Also, some interesting chemical transformations and rearrangements were observed. 相似文献
36.
The profile hidden Markov model (PHMM) is widely used to assign the protein sequences to their respective families. A major limitation of a PHMM is the assumption that given states the observations (amino acids) are independent. To overcome this limitation, the dependency between amino acids in a multiple sequence alignment (MSA) which is the representative of a PHMM can be appended to the PHMM. Due to the fact that with a MSA, the sequences of amino acids are biologically related, the one-by-one dependency between two amino acids can be considered. In other words, based on the MSA, the dependency between an amino acid and its corresponding amino acid located above can be combined with the PHMM. For this purpose, the new emission probability matrix which considers the one-by-one dependencies between amino acids is constructed. The parameters of a PHMM are of two types; transition and emission probabilities which are usually estimated using an EM algorithm called the Baum-Welch algorithm. We have generalized the Baum-Welch algorithm using similarity emission matrix constructed by integrating the new emission probability matrix with the common emission probability matrix. Then, the performance of similarity emission is discussed by applying it to the top twenty protein families in the Pfam database. We show that using the similarity emission in the Baum-Welch algorithm significantly outperforms the common Baum-Welch algorithm in the task of assigning protein sequences to protein families. 相似文献
37.
Mohamed-Elamir F. Hegazy Tarik A. Mohamed Fathy F. Abdel-Latif Mansour S. Alsaid Abdelaaty A. Shahat Paul W. Paré 《Phytochemistry letters》2013,6(3):383-386
Chemical investigations of the soft coral Sarcophyton trocheliophorum, has led to the isolation of six cembranoids, two of which are new, Trochelioid A (1) and B (2), and one, 16-oxosarcophytonin E (3) isolated from nature for the first time. Additionally, two have been isolated from S. trocheliophorum for the first time (4 and 6). Structures were elucidated by employing extensive NMR and HR-FAB-MS experimentation. 相似文献
38.
Corzo Remigio Amelia Chaney Rufus L. Baker Alan J. M. Edraki Mansour Erskine Peter D. Echevarria Guillaume van der Ent Antony 《Plant and Soil》2020,449(1-2):11-37
Plant and Soil - Phytoextraction is an in situ technique that can be applied to minerals and mining wastes using hyperaccumulator plants to purposely bio-concentrate high levels of metals or... 相似文献
39.
Ghazizadeh Hamideh Rezaei Majid Avan Amir Fazilati Mohammad Pasdar Alireza Tavallaie Shima Kazemi Elham Seyedi Seyed Mohammad Reza Ferns Gordon A. Azimi-Nezhad Mohsen Ghayour-Mobarhan Majid 《Molecular biology reports》2020,47(2):867-875
Molecular Biology Reports - Metabolic syndrome (MetS) is associated with a pro-inflammatory state and endothelial dysfunction that places subjects with MetS at a higher risk of atherosclerosis.... 相似文献