全文获取类型
收费全文 | 469篇 |
免费 | 18篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 12篇 |
2017年 | 8篇 |
2016年 | 19篇 |
2015年 | 23篇 |
2014年 | 31篇 |
2013年 | 42篇 |
2012年 | 47篇 |
2011年 | 47篇 |
2010年 | 25篇 |
2009年 | 18篇 |
2008年 | 25篇 |
2007年 | 26篇 |
2006年 | 21篇 |
2005年 | 21篇 |
2004年 | 17篇 |
2003年 | 14篇 |
2002年 | 19篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 1篇 |
1997年 | 9篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 6篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 1篇 |
1983年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有487条查询结果,搜索用时 15 毫秒
11.
Marco Cucurachi Matteo Busconi Mariangela Marudelli Giovanna Soffritti Corrado Fogher 《Molecular biology reports》2013,40(7):4317-4325
Eight genes encoding cellulolytic enzymes were obtained by direct PCR amplification of genomic DNA recovered from woodland soil samples. The direct amplifications were carried out by using primers designed from available online cellulase nucleotide sequences. The isolated genes were all different from each other and homologous to endo-β-1,4-glucanases of Bacillus subtilis. The cellulases were functionally expressed in Escherichia coli and tested on soluble substrate at 37 and 60 °C, showing different cellulolytic activities. Among these, the enzyme renamed CelWS6 exhibited good activity at higher temperatures. Further analysis of CelWS6 showed a high performance in acid environments (between pH 4.0 and 6.0) and at elevated temperatures with its maximum activity at pH 5.0 and 50 °C. At the optimum pH, it was very stable since more than 80 % of its original activity was maintained after an incubation of 120 min at 60 °C. Because the cellulases had different cellulolytic activities, but similar amino acid sequences, it was possible to assess the relationship between sequence and protein function. 相似文献
12.
Mariangela Ceruso Daniela Vullo Andrea Scozzafava Claudiu T. Supuran 《Bioorganic & medicinal chemistry》2013,21(22):6929-6936
Reaction of cyanuryl fluoride with sulfanilamide or 4-aminoethylbenzenesulfonamide afforded triazinyl-substituted benzenesulfonamides incorporating fluorine, which were further derivatized by reaction with amines, amino alcohols, amino acids or amino acid esters. Inhibition studies of all the human (h) carbonic anhydrase (CA, EC 4.2.1.1) isoforms, hCA I–XIV with these compounds revealed that they show moderate-weak inhibition of hCA III, IV, VA and XIII, rather moderate inhibition against hCA I, VI, and IX, and excellent inhibition of the physiologically relevant hCA II, VII and XII. The inhibition profile of these fluorine containing triazinyl sulfonamides is thus very different from the corresponding analogs incorporating chlorine, which were previously investigated as inhibitors of some of these enzymes. 相似文献
13.
Claudio Battilocchio Giovanna Poce Salvatore Alfonso Giulio Cesare Porretta Sara Consalvi Lidia Sautebin Simona Pace Antonietta Rossi Carla Ghelardini Lorenzo Di Cesare Mannelli Silvia Schenone Antonio Giordani Luigia Di Francesco Paola Patrignani Mariangela Biava 《Bioorganic & medicinal chemistry》2013,21(13):3695-3701
We report the synthesis and bio-pharmacological evaluation of a class of pyrrole derivatives featuring a small appendage fragment (carbaldehyde, oxime, nitrile) on the central core. Compound 1c proved to be extremely effective in vivo, showing an interesting anti-nociceptic profile that is comparable to reference compounds already marketed, hence representing a great stimulus for a further improvement of this class of molecules. 相似文献
14.
15.
16.
17.
18.
Papis E Bernardini G Gornati R Menegola E Prati M 《Gene expression patterns : GEP》2007,7(1-2):137-142
The triazole derivative Triadimefon (FON) is a systemic fungicide used to control powdery mildews, rusts, and other fungal pests. Some data have already been published about the teratogenic activity of this compound: craniofacial malformations were found in mouse, rat, and Xenopus laevis embryos exposed to FON. These alterations were correlated to defective branchial arch development possibly caused by abnormal neural crest cell (NCC) migration into the branchial mesenchyme. As the migration of NCCs is controlled by the HOX code and by an anteroposterior retinoic acid (RA) gradient, we analyzed the expression of CYP26, a key enzyme in RA metabolism, following FON exposure. The increased expression of this gene and the ability of citral (a RA inhibitor) to reduce the teratogenic effects of the fungicide support the notion that endogenous RA is involved in the mechanism of action of FON. Moreover, by in situ hybridization, we studied the effects of FON exposure at gastrula stage on the expression of some genes involved in craniofacial development, hindbrain patterning, and NCC migration. We observed abnormal localization of xCRABP, Hoxa2 and Xbap signal expression at the level of migrating NCC domains, whereas in the hindbrain, we did not find any alteration in Krox20 and Hoxa2 expression. 相似文献
19.
del Cerro Pablo Ayala-García Paula Jiménez-Guerrero Irene López-Baena Francisco Javier Vinardell José María Megías Manuel Hungria Mariangela Gil-Serrano Antonio M. Pérez-Montaño Francisco Ollero Francisco Javier 《Plant and Soil》2019,434(1-2):185-201
Plant and Soil - Previous studies have shown that pH, rather than calcium (Ca), is the main reason why some Lupinus species are sensitive to nutrient solutions mimicking calcareous soils; however,... 相似文献
20.