全文获取类型
收费全文 | 1456篇 |
免费 | 132篇 |
出版年
2022年 | 8篇 |
2021年 | 21篇 |
2019年 | 16篇 |
2018年 | 17篇 |
2017年 | 13篇 |
2016年 | 27篇 |
2015年 | 36篇 |
2014年 | 37篇 |
2013年 | 72篇 |
2012年 | 73篇 |
2011年 | 75篇 |
2010年 | 51篇 |
2009年 | 39篇 |
2008年 | 77篇 |
2007年 | 85篇 |
2006年 | 65篇 |
2005年 | 60篇 |
2004年 | 67篇 |
2003年 | 68篇 |
2002年 | 73篇 |
2001年 | 47篇 |
2000年 | 42篇 |
1999年 | 26篇 |
1998年 | 31篇 |
1997年 | 14篇 |
1996年 | 24篇 |
1995年 | 18篇 |
1994年 | 17篇 |
1993年 | 21篇 |
1992年 | 34篇 |
1991年 | 23篇 |
1990年 | 21篇 |
1989年 | 26篇 |
1988年 | 15篇 |
1987年 | 10篇 |
1986年 | 25篇 |
1985年 | 26篇 |
1984年 | 20篇 |
1983年 | 18篇 |
1982年 | 16篇 |
1981年 | 10篇 |
1980年 | 12篇 |
1979年 | 11篇 |
1978年 | 8篇 |
1977年 | 20篇 |
1974年 | 9篇 |
1973年 | 7篇 |
1972年 | 10篇 |
1971年 | 7篇 |
1968年 | 8篇 |
排序方式: 共有1588条查询结果,搜索用时 13 毫秒
11.
Toshihisa Ohshima Christian Wandrey Miyuki Sugiura Kenji Soda 《Biotechnology letters》1985,7(12):871-876
Summary Screening of leucine and alanine dehydrogenases in thermophilicBacillus strains was carried out to develop their utilization for industrial and analytical catalysts. Out of the 28 thermophilic strains tested, four strains,Bacillus sp. DSM 405, 730 and 1521, andB.
sphaericus DSM 462, abundantly produce both the enzymes. Both the enzyme activities in these thermophiles are enhanced by addition of the substrates to a polypeptone medium. 相似文献
12.
13.
Chemotaxonomy of Gibberella zeae with special reference to production of trichothecenes and zearalenone. 总被引:8,自引:7,他引:1
下载免费PDF全文
![点击此处可从《Applied microbiology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
By adopting a single-spore isolation technique, 113 isolates of Gibberella zeae, the perfect stage of Fusarium graminearum, were isolated from rice stubbles in barley and wheat fields and tested for production of trichothecenes and zearalenone on rice grains. Of the isolates, 93% produced the trichothecenes, and they could be subdivided into two chemotaxonomic groups: nivalenol and fusarenon-X producers and deoxynivalenol and 3-acetyldeoxynivalenol producers. No cross production of these two types of trichothecenes was observed in these isolates. Zearalenone was detected in 68% of the isolates, but no clear relationship could be observed regarding its position with respect to the two chemotaxonomic groups. 相似文献
14.
15.
A putative gene of tobacco chloroplast coding for ribosomal protein similar to E. coli ribosomal protein S19. 总被引:16,自引:10,他引:6
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A partial sequence of a cloned 3.2 Md BamHI fragment from tobacco chloroplast DNA revealed the occurrence of a putative gene for ribosomal protein. The putative gene is located on the left margin of the large single-copy region in the chloroplast DNA. The coding region contains 276 bp (92 codons). The amino acid sequence deduced from the DNA sequence shows 55% homology with that of E. coli S19 (91 amino acid residues). 相似文献
16.
17.
Kenichi Takaya 《Biotechnic & histochemistry》1967,42(4):207-211
The applicability of Luxol fast blue MBS as a 0.1% solution in 0.05% acetic acid to the staining of mitochondria, first recognized in rat kidney by Shanklin and Nassar (Stain Techn., 34: 257-60. 1959), was confirmed in various organs (formalin-Zenker and Regaud's fixations; paraffin embedding) of the mouse and bullfrog. In liver cells and in the epithelium of renal tubules, mitochondria were stained green, selectively and clearly. The dark cells of the renal tubules and the middle piece of sperms in both animals were conspicuously demonstrated by their dense assemblages of green granules. The periodic acid-Schiff procedure proposed by Shanklin and Nassar as a counterstain was replaced by staining in 0.5% aqueous phloxine, 2-3 min; differentiation in 5% phosphotungstic acid, 2 min; and washing in water, 5 min. This simplified and accelerated the techique, and gave a better color contrast. Advantages of Luxol fast blue MBS and phloxine staining over traditional methods for mitochondria in paraffin sections are: durability of the stain, high specificity, simplicity of procedure, and constant result. 相似文献
18.
T Shiraki M Uesugi Y Sugiura 《Biochemical and biophysical research communications》1992,188(2):584-589
Dynemicin A, which is a hybrid antitumor antibiotic containing anthraquinone and enediyne cores, abstracts the C-1' hydrogen of DNA deoxyribose and then the damaged DNA leads to strand breaks with the formation of 5'- and 3'-phosphate termini. The lesions of C-4' hydrogen also occur at 3' side of G.C base pairs (i. e., 5'-CT and 5'-GA), leading to 5'-phosphate and 3'-phosphoglycolate termini or 4'-hydroxylated abasic sites. The C-1' hydrogen abstraction by dynemicin A is distinct from the preferential C-5' hydrogen abstraction of calicheamicin and neocarzinostatin. 相似文献
19.
20.
Meenu Kapoor Tatsuya Wakasugi Koichi Yoshinaga Masahiro Sugiura 《Molecular & general genetics : MGG》1996,250(6):655-664
ThechiL gene product is involved in the light-independent synthesis of chlorophyll in photosynthetic bacteria, green algae and non-flowering plants. The chloroplast genome ofChlorella vulgaris strain C-27 contains the first example of a splitchiL gene, which is interrupted by a 951 bp group I intron in the coding region. In vitro synthesized pre-mRNA containing the entire intron and parts of the flanking exon sequences is able to efficiently self-splice in vitro in the presence of a divalent and a monovalent cation and GTP, to yield the ligated exons and other splicing intermediates characteristic of self-splicing group I introns. The 5 and 3 splice sites were confirmed by cDNA sequencing and the products of the splicing reaction were characterized by primer extension analysis. The absence of a significant ORF in the long P9 region (522 nt), separating the catalytic core from the 3 splice site, makes this intron different from the other known examples of group I introns. Guanosine-mediated attack at the 3 splice site and the presence of G-exchange reaction sites internal to the intron are some other properties demonstrated for the first time by an intron of a protein-coding plastid gene. 相似文献