全文获取类型
收费全文 | 537篇 |
免费 | 41篇 |
专业分类
578篇 |
出版年
2023年 | 2篇 |
2022年 | 6篇 |
2021年 | 9篇 |
2020年 | 11篇 |
2019年 | 6篇 |
2018年 | 13篇 |
2017年 | 15篇 |
2016年 | 22篇 |
2015年 | 41篇 |
2014年 | 30篇 |
2013年 | 42篇 |
2012年 | 17篇 |
2011年 | 17篇 |
2010年 | 27篇 |
2009年 | 29篇 |
2008年 | 19篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 14篇 |
2004年 | 18篇 |
2003年 | 11篇 |
2002年 | 16篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 6篇 |
1991年 | 10篇 |
1990年 | 8篇 |
1989年 | 8篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1975年 | 2篇 |
1973年 | 3篇 |
1971年 | 4篇 |
1970年 | 2篇 |
1958年 | 1篇 |
排序方式: 共有578条查询结果,搜索用时 15 毫秒
1.
The paper presents the analysis of the frequency, density, and distribution of recombination sites in the male meiosis of the domestic cat (Felis silvestris catus). The study was carried out using immunofluorescent staining of synaptonemal complex (SC) proteins, centromeric proteins and mismatch repair protein MLH1, a reliable marker of crossingover sites. We mapped 2633 sites of crossing over in 1098 individual autosomes. Based on these data, we estimated the total length of the genetic map of the domestic cat to be 2176 centimorgans. Positive correlation between the length of SC and the number of recombination sites common for mammalians was also found in the domestic cat. It was shown that this species was characterized by the highest density of recombination and the lowest interference in mammals. 相似文献
2.
Mapping of the silver fox genes: assignments of the genes for ME1, ADK, PP, PEPA, GSR, MPI, and GOT1
T B Nesterova N B Rubtsov S M Zakian V G Matveeva A S Graphodatsky 《Cytogenetics and cell genetics》1991,56(2):125-127
Evidence is presented for the assignment of seven fox genes on the basis of the segregation data for chromosomes and enzymes of fox x Chinese hamster somatic cell hybrids. The chromosomal loci of the following enzyme genes were determined: ME1, VFU1; ADK and PP, VFU4; PEPA, VFU5; GSR, VFU7; and MPI and GOT1, VFU15. The localization of these genes now extends the fox genetic map to 22 mapped genes. Based on comparative analysis of mammalian genetic maps, karyotype evolution in Carnivora is discussed. 相似文献
3.
4.
Using ethnographic data collected in a second grade classroom over the course of a school year, this paper describes the ways in which one school's discourse of liberalism is deleteriously deployed. We view the school's discipline creed as emblematic of the school's liberal curriculum, and interrogate the effects on four African American boys in the classroom when the school enacts this creed. Despite the agency that these boys obviously had, they were unable to control the ways in which they were placed at a structural disadvantage and manipulated by a system far more powerful than they were. The results were that these four boys suffered. Not only did the intended liberal curriculum fail to be translated fully into the enacted curriculum, the liberal underpinnings of this curriculum precluded teachers and students from taking any critical stance. 相似文献
5.
Excised cotyledons of Pinus radiata D. Don cultured under shoot-forming(plus benzyladenine) and non shoot-forming (minus benzyladenine)conditions for 10 and 21 days were fed U-[14C]-glucose for 3h in the light followed by a 3 h chase period. The labellingof individual metabolites as well as 14C incorporation intoprotein was assessed. It was found that the general metabolicpatterns were qualitatively the same in shoot-forming and nonshoot-forming conditions, however, metabolism leading to respirationas well as to the synthesis of some amino acids and proteinsynthesis was enhanced in the shoot-forming cultures. (Received February 16, 1987; Accepted July 8, 1987) 相似文献
6.
M V Reznikov R Fidler P M Rubtsov K G Skriabin P M Chumakov V S Prasolov A A Baev 《Molekuliarnaia biologiia》1989,23(6):1692-1699
The new system for the transfer and expression of foreign genes based on retroviral vectors pPS-neo, conferring neomycin resistance was constructed. The BALB/c mouse cell lines producing highly active human growth hormone (more than 7 micrograms/ml into culture medium) were constructed using these vectors. An antibody column was used to purify the growth hormone from cell culture medium. Possibilities of producers to be applied for gene therapy are discussed. 相似文献
7.
V. I. Yermolaev G. I. Karasik T. M. Khlebodarova N. M. Matveeva M. R. Mullakandov A. M. Nayakschin T. V. Shumny N. B. Rubtsov O. L. Serov O. K. Baranov 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,78(1):93-96
Summary Using cloned cDNA for human 2-macroglobulin (A2M) as a probe, mink-Chinese hamster hybrid cells were analysed. The results allowed us to assign a gene for A2M to mink chromosome 9. Breeding tests demonstrated that the Lpm-locus coding for other related -macroglobulin protein and the gene for peptidase B (PEPB) are linked 11±3 cm apart. The PEPB gene is located on mink chromosome 9, and hence, the Lpw-locus is on the same mink chromosome. The relationship of the genetic systems controlling the isotypically different -macroglobulins in mink serum are discussed. 相似文献
8.
Richard W. Joy IV Kamlesh R. Patel Trevor A. Thorpe 《Plant Cell, Tissue and Organ Culture》1988,13(3):219-228
The effect of ascorbic acid on growth and shoot formation in callus cultures of tobacco (Nicotiana tabacum L.) was investigated, using young (4–12 subcultures) and old (more than 30 subcultures) tissue. It was found that ascorbate, at levels of 4–8×10-4M, enhanced shoot formation in both young and old callus. Treatment with ascorbate also speeded up the shoot-forming process. In addition, ascorbate completely reversed the inhibition of shoot formation by gibberellic acid in young callus, but was less effective in old callus. 相似文献
9.
10.
A. A. Gradov S. D. Pack M. A. Sukoyan N. B. Rubtsov M. N. Bochkarev O. L. Serov 《Molecular & general genetics : MGG》1985,200(3):433-438
Summary A panel of clones of mink-Chinese hamster somatic cell hybrids was analysed to obtain data for assigning the genes for thymidine kinase-1 (TK1), galactokinase (GALK), subunit C of aldolase (ALDC), and esterase D (ESD) to specific mink chromosomes. The results demonstrate that the genes for TK1, GALK, ALDC and ESD are syntenic and located on mink chromosome 8. Prometaphase analysis of transformed mouse cells obtained by transfer of mink genes by means of metaphase chromosomes demonstrated the presence of mink chromosome 8 fragments of different sizes in some of the independent transformants. Segregation analysis of these fragments and mink TK1, GALK, ALDC and ESD allowed us to assign the genes for TK1 and GALK to 8p24, ALDC to pter-8p25, and ESD to 8q24-8qter. 相似文献