全文获取类型
收费全文 | 751篇 |
免费 | 55篇 |
专业分类
806篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 11篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 7篇 |
2015年 | 23篇 |
2014年 | 26篇 |
2013年 | 44篇 |
2012年 | 55篇 |
2011年 | 61篇 |
2010年 | 26篇 |
2009年 | 21篇 |
2008年 | 50篇 |
2007年 | 67篇 |
2006年 | 58篇 |
2005年 | 47篇 |
2004年 | 50篇 |
2003年 | 30篇 |
2002年 | 46篇 |
2001年 | 7篇 |
2000年 | 3篇 |
1999年 | 15篇 |
1998年 | 13篇 |
1997年 | 12篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 9篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 4篇 |
1990年 | 6篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1978年 | 2篇 |
1976年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有806条查询结果,搜索用时 15 毫秒
801.
Denise Busson Bernadette Limbourg-Bouchon Marie-Christine Mariol Thomas Preat Claudie Lamour-Isnard 《Development genes and evolution》1988,197(4):221-230
Summary
Fused is a segmentation gene belonging to the segment-polarity class. Mutations at thefused locus are known to display pleiotropic effects, causing zygotically determined anomalies of ovaries and of some adult cuticular
structures, and maternally determined embryonic segmentation defects. In order to determine the amorphic phenotype offused and to study the genetical basis of its pleiotropy, newfused alleles (18 viable and 11 lethal) were isolated. The phenotype of these mutants and of others already known are described,
taking into account zygotic and maternal effects. The main results provided by this analysis are as follows. Firstly, allfused alleles show the whole complex fused phenotype, and a good correlation is observed between the strength of the wing and segmentation
defects, suggesting that a single function is involved in both processes. Secondly, all embryonic and larval lethals carry
deficiencies which allow us to localizefused between the 17C4 and 17D2 bands of the X-chromosome. Thirdly, the 24 viable and 2 pupal lethals examined behave as point
mutants, as shown cytologically or by Southern blot analysis. However, only one of them, the pupal lethalfu
mH63 was proven to carry a nullfused allele, since it displays in germ-line clones a strong maternal phenotype and a very low zygotic rescue, similar to those
of the small deficiencyDf(1)fu
z4. The phenotype of the amorphic mutant indicates that zygotic ezpression offused is required for normal metamorphosis, while maternal expression is necessary for a normal segmentation pattern, since a complete
loss offused expression during oogenesis cannot be compensated zygotically. 相似文献
802.
The cytoplasm of oocytes of Xenopus laevis is enriched in several soluble proteins which are either absent from the nucleus or are present there at very low concentrations. These molecules, collectively referred to as karyophobic (from the Greek verbs oβιν and oβλoθαi which are meant here in the sense of “to be afraid of” or “to avoid”) proteins represent more than 20% of the total soluble cytoplasmic proteins and include some of the most abundant soluble cellular components. They may be recovered from high-speed supernatant (S-100) fractions and, following sucrose gradient centrifugation, most of them appear in the form of complexes smaller than 8.5S. On denaturation in urea and two-dimensional gel electrophoresis these proteins appear to be comprised of polypeptides of widely different sizes (ca Mr 15 000–230 000) and isoelectric points covering a broad range of pH values (4.2–8.0). Gel filtration and isoelectric focusing of native karyophobic proteins show that the majority occur in acidic complexes smaller than Mr 150 000, including one case of a small karyophobic protein (C9; Mr 30 000). In contrast to karyophilic proteins and proteins equilibrating between nucleus and cytoplasm karyophobic soluble proteins from [35S]methionine-labelled ooplasms, when injected into unlabelled oocytes, remain in the cytoplasm. Human proteins with a similar karyophobic behaviour have been identified in fractions of soluble proteins from HeLa cells; there, the major karyophobic protein (HCa, Mr 36 000) is also one of the most abundant soluble proteins.We conclude that the specific nucleocytoplasmic compartmentalization of soluble proteins is governed not only by the principles of exclusion of large molecules from nuclear uptake and the existence of karyophilic signals in certain proteins but that a series of soluble, globular proteins exist in the cytoplasm, which have other molecular features which selectively exclude them from distribution over the nucleus. The possible functional role of the selective enrichment of these abundant proteins, which so far have escaped attention, in establishing a cytoplasmic milieu is discussed. 相似文献
803.
Mathias Choquer Martine Boccara Isabelle R Gon?alves Marie-Christine Soulié Anne Vidal-Cros 《European journal of biochemistry》2004,271(11):2153-2164
We describe a strategy for systematic amplification of chitin synthase genes (chs) in the filamentous ascomycetes plant-pathogen Botrytis cinerea using PCR with multiple degenerate primers designed on specific and conserved sequence motifs. Eight distinct chs genes were isolated, named Bcchs I, II, IIIa, IIIb, IV, V, VI and VII. They probably constitute the entire chs multigenic family of this fungus, as revealed by careful analysis of six euascomycetes genomes. Bcchs I, IIIa, IIIb, IV and VI genes were subjected to DNA walking and their deduced amino acid sequences were compared by hydrophobic cluster analysis (HCA) to localize putative residues critical for CHS activity. HCA also enabled us to highlight three different transmembrane topologies of the CHS membranous isoenzymes. We found that the N-terminal region of the BcCHSI isoenzyme, and its orthologues in other euascomycetes, probably contain folded peptide motifs with conserved tyrosine residues. Their putative role is discussed. The BcCHSVII isoenzyme appeared to belong to a new class of CHS orthologues that was demonstrated by phylogenetic study to branch apart from division 1 and 2 of CHS. 相似文献
804.
805.
806.
Philippe Camus Naïma Abbadi Marie-Christine Perrier Michèle Chéry Simone Gilgenkrantz 《Human genetics》1996,97(2):247-250
Rett syndrome (RS) is a neurologic disorder with an exclusive incidence in females. A nonrandom X-inactivation could provide insight into the understanding of this disease. We performed molecular analysis based on the differential methylation of the active and inactive X with probe M27ß, taking into account the parental origin of the two Xs, in 30 control girls, 8 sisters, and 30 RS girls. In 27 control an 31 RS mothers, the inactivation status of the X transmitted to their daughters was also analyzed. The results showed a significantly increased frequency of partial paternal X inactivation (> 65%) in lymphocytes from 16/30 RS compared with 4/30 controls (P = 0.001). These results do not support the hypothesis of a monogenic X-linked mutation but should be taken into account when researching the etiology of this desease. 相似文献