全文获取类型
收费全文 | 157篇 |
免费 | 9篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 3篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 3篇 |
2014年 | 4篇 |
2013年 | 1篇 |
2012年 | 18篇 |
2011年 | 13篇 |
2010年 | 7篇 |
2009年 | 5篇 |
2008年 | 10篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 8篇 |
2004年 | 13篇 |
2003年 | 6篇 |
2002年 | 4篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1994年 | 1篇 |
1988年 | 1篇 |
1986年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有166条查询结果,搜索用时 156 毫秒
161.
Eray Çalışkan Alpaslan Kaplan Güldeniz Şekerci İrfan Çapan Suat Tekin Sultan Erkan Kenan Koran Süleyman Sandal Ahmet O. Görgülü 《Journal of biochemical and molecular toxicology》2023,37(8):e23388
Peptides are one of the leading groups of compounds that have been the subject of a great deal of biological research and still continue to attract researchers' attention. In this study, a series of tripeptides based on tyrosine amino acids were synthesized by the triazine method. The cytotoxicity properties of all compounds against human cancer cell lines (MCF-7), ovarian (A2780), prostate (PC-3), and colon cancer cell lines (Caco-2) were determined by the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide assay method, and % cell viability and logIC50 values of the compounds were calculated. Significant decreases in cell viability were observed in all cells (p < 0.05). The comet assay method was used to understand that the compounds that showed a significant decrease in cell viability had this effect through DNA damage. Most of the compounds exhibited cytotoxicity by DNA damage mechanism. Besides, their interactions between investigated molecule groups with PDB ID: 3VHE, 3C0R, 2ZCL, and 2HQ6 target proteins corresponding to cancer cell lines, respectively, were investigated by docking studies. Finally, molecules with high biological activity against biological receptors were determined by ADME analysis. 相似文献
162.
163.
L. Konak Y. Kolcuoğlu E. Ozbek A. Colak B. Ergenoglu 《Applied Biochemistry and Microbiology》2014,50(1):25-29
The D-glucose/D-xylose isomerase was purified from a thermophilic bacterium, Geobacillus thermodenitrificans TH2, by precipitating with heat shock and using Q-Sepharose ion exchange column chromatography, and then characterized. The purified enzyme had a single band having molecular weight of 49 kDa on SDS-PAGE. In the presence of D-glucose as a substrate, the optimum temperature and pH of the enzyme were found to be 80°C and 7.5, respectively. The purified xylose isomerase of G. thermodenitrificans TH2 was extremely stable at pH 7.5 after 96 h incubation at 4°C and 50°C. When the thermal stability profile was analyzed, it was determined that the purified enzyme was extremely stable during incubation periods of 4 months and 4 days at 4°C and 50°C, respectively. The K m and V max values of the purified xylose isomerase from G. thermodenitrificans TH2 were calculated as 32 mM and 4.68 μmol/min per mg of protein, respectively. Additionally, it was detected that some metal ions affected the enzyme activity at different ratios. The enzyme was active and stable at high temperatures and nearly neutral pHs which are desirable for the usage in the food and ethanol industry. 相似文献
164.
Stable, nonracemic axially chiral hemiaminals (O,N-hemiacetals) have been synthesized stereoselectively from lithium aluminum hydride (LiAlH4) reductions of nonracemic 5-methyl- and 5-isopropyl-3-(o-aryl)-2-thioydantoins in tetrahydrofuran (THF) at room temperature in 10 min. Predominantly S -configured hemiaminals at C-4 of the heterocyclic ring were produced from the S-configured thiohydantoins at C-5 (by 80% when the C5 substituent is methyl and by 97% when it is isopropyl). The configuration at C-5 was retained during the reduction reaction. The stereochemical outcome of the axially chiral hemiaminals resulted from their conformational preferences. 相似文献
165.
166.
Dicle Çevik Suat Erdogan Riza Serttas Yüksel Kan Hasan Kırmızıbekmez 《化学与生物多样性》2023,20(1):e202200589
Cytotoxic activity-guided fractionation studies on Glycyrrhiza echinata roots led to the isolation of eight compounds ( 1 – 8 ). Chemical structures of the isolates were identified by NMR and MS analysis. Among the tested molecules, retrochalcones namely echinatin ( 3 ) (IC50=23.45–41.83 μM), licochalcone B ( 4 ) (IC50=36.04–39.53 μM) and tetrahydroxylmethoxychalcone ( 5 ) (IC50=7.09–80.81 μM) were the most active ones against PC3, MCF7 and HepG2 cells. Moreover, 5 exhibited selectivity on prostate cancer cells (SI: 5.19). Hoechst staining and Annexin V/PI binding assays as well as cell cycle analysis on the compounds 3 (23 μM) and 5 (5 and 7 μM) demonstrated that these retrochalcones induced apoptosis and significantly suppressed cell cycle in G1 and G2/M phases. Furthermore, 3 and 5 showed antimigratory effects on PC3 cells by wound healing assay. The results indicated that tested retrochalcones most particularly 5 could be potential anticancer drug candidates that prevent proliferation and migration of cancer cells. 相似文献