全文获取类型
收费全文 | 623篇 |
免费 | 26篇 |
出版年
2023年 | 3篇 |
2022年 | 2篇 |
2021年 | 22篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 25篇 |
2014年 | 34篇 |
2013年 | 38篇 |
2012年 | 49篇 |
2011年 | 50篇 |
2010年 | 30篇 |
2009年 | 29篇 |
2008年 | 38篇 |
2007年 | 39篇 |
2006年 | 27篇 |
2005年 | 28篇 |
2004年 | 33篇 |
2003年 | 26篇 |
2002年 | 20篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1972年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有649条查询结果,搜索用时 38 毫秒
641.
Bacterial biosensors for monitoring toxic metals 总被引:1,自引:0,他引:1
642.
643.
B Nakhai P Sridhar G P Talwar S E Hasnain 《Indian journal of biochemistry & biophysics》1991,28(4):237-242
A cDNA encoding the alpha subunit of human chorionic gonadotropin, a placental glycoprotein hormone, was cloned downstream to the viral polyhedrin gene promoter of Autographa california nuclear polyhedrosis virus and the recombinant transfer vector was used to co-transfect Spodoptera frugiperda cells growing in culture. Recombinant baculovirus carrying the alpha hCG gene was detected and isolated after dot hybridization using supernatant from co-transfected cells. Recombinant vAc alpha hCG having a replacement of the viral polyhedrin gene, which is hyper-transcribed very late in the infection cycle, with the alpha hCG cDNA was purified after a single round of plaque purification. Insect cell culture infected with vAc alpha hCG, secreted high levels of hCG which was biologically active. 相似文献
644.
Malkaram Sridhar Achary Hampapathalu Adimurthy Nagarajaram 《Journal of biosciences》2008,33(5):699-713
Molecular docking has been used to compare and contrast the binding modes of oestradiol with the wild-type and some disease-associated
mutant forms of the human CYP1b1 protein. The receptor structures used for docking were derived from molecular dynamics simulations
of homology-modelled structures. Earlier studies involving molecular dynamics and principal component analysis indicated that
mutations could have a disruptive effect on function, by destabilizing the native properties of the functionally important
regions, especially those of the haem-binding and substrate-binding regions, which constitute the site of catalytic activity
of the enzyme. In order to gain more insights into the possible differences in substrate-binding and catalysis between the
wild-type and mutant proteins, molecular docking studies were carried out. Mutants showed altered protein-ligand interactions
compared with the wild-type as a consequence of changes in the geometry of the substrate-binding region and in the position
of haem relative to the active site. An important difference in ligand-protein interactions between the wild-type and mutants
is the presence of stacking interaction with phenyl residues in the wild-type, which is either completely absent or considerably
weaker in mutants. The present study revealed essential differences in the interactions between ligand and protein in wild-type
and disease mutants, and helped in understanding the deleterious nature of disease mutations at the level of molecular function. 相似文献
645.
Plumbagin (5-hydroxy-2-methyl-1,4-naphthaquinone), a compound derived from the root of thePlumbago zeylanica plant, was effective in selectively eliminating stringent, conjugative, multidrug-resistant plasmids fromEscherichia coli strains. Simultaneous loss of resistance to antibiotics in plumbagin-treated cells indicated loss of plasmid. However, such R plasmids are refractory to treatment with acridine orange and sodium dodecyl sulfate, which are widely used in curing techniques. 相似文献
646.
647.
648.
Prabhakaran Vasantha-Srinivasan Sridhar Shanmuga-Priya Yeon Soo Han Narayanaswamy Radhakrishnan Kesavan Amala Sengodan Karthi Sengottayan Senthil-Nathan 《Entomological Research》2023,53(11):485-508
Extracts of botanical origin naturally contain a complex mixture of chemicals considered effective in managing lepidopteran pests. Chemical screening of the ethanolic leaf extracts of two fig tree species, Ficus lyrata and Ficus auriculata, delivered 12 and 15 phyto-compounds with relatively high peak area percentages in phytol and flavone, respectively. Larvicidal activity against Spodoptera litura yielded higher mortality rates at maximum-concentration treatment (600 ppm) with Ficus lyrata (91.3%) and Ficus auriculata (98.5%) extracts during the second instar. Sub-lethal dosages (300 ppm) of both Ficus lyrata and Ficus auriculata extracts impeded the development and reproduction of lepidopteran pests. The enzyme-inhibition activity of both fig extracts elicited a significant reduction in the major digestive enzymes alkaline phosphatase, acid phosphatase, and lactate dehydrogenase dose-responsively. Mid-gut histological screening of Ficus lyrata and Ficus auriculata extracts displayed gut lumen disruptions, shape alterations of columnar cells, and brush-border membrane damage. Further, the non-target toxicity of fig extracts against the red worm Eisenia foetida was minimal compared with that of the chemical temephos. Overall, the Ficus extracts proved to be eco-friendly strategies for managing the polyphagous pest Spodoptera litura and are potentially more sustainable and less harmful to non-target earthworms. Nonetheless, in silico predictions suggest that the active compounds in fig extracts are predominantly toxic against honeybees (16 compounds) and violate TICE rules (10 compounds). Therefore, the biological actions of fig extracts' individual novel chemistries need to be examined on target and non-target species to develop better pest management strategies. 相似文献
649.