全文获取类型
收费全文 | 273篇 |
免费 | 3篇 |
国内免费 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 2篇 |
2021年 | 11篇 |
2020年 | 11篇 |
2019年 | 15篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 2篇 |
2011年 | 1篇 |
2010年 | 2篇 |
2009年 | 13篇 |
2008年 | 17篇 |
2007年 | 19篇 |
2006年 | 19篇 |
2005年 | 9篇 |
2004年 | 3篇 |
2003年 | 6篇 |
2002年 | 1篇 |
2001年 | 9篇 |
2000年 | 10篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 14篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有291条查询结果,搜索用时 15 毫秒
91.
92.
Sophie Charrasse Thierry Lorca Marcel Dore Christian Larroque 《Experimental cell research》2000,254(2):249
Cytoskeleton reorganization, leading to mitotic spindle formation, is an M-phase-specific event and is controlled by maturation promoting factor (MPF: p34cdc2–cyclinB1 complex). It has previously been demonstrated that the p34cdc2–cyclin B complex associates with mitotic spindle microtubules and that microtubule-associated proteins (MAPs), in particular MAP4, might be responsible for this interaction. In this study, we report that another ubiquitous MAP, TOG in human and its homologue in Xenopus XMAP215, associates also with p34cdc2 kinase and directs it to the microtubule cytoskeleton. Costaining of Xenopus cells with anti-TOGp and anti-cyclin B1 antibodies demonstrated colocalization in interphase cells and also with microtubules throughout the cell cycle. Cyclin B1, TOG/XMAP215, and p34cdc2 proteins were recovered in microtubule pellets isolated from Xenopus egg extracts and were eluted with the same ionic strength. Cosedimentation of cyclin B1 with in vitro polymerized microtubules was detected only in the presence of purified TOG protein. Using a recombinant C-terminal TOG fragment containing a Pro-rich region, we showed that this domain is sufficient to mediate cosedimentation of cyclin B1 with microtubules. Finally, we demonstrated interaction between TOG/XMAP215 and cyclin B1 by co-immunoprecipitation assays. As XMAP215 was shown to be the only identified assembly promoting MAP which increases the rapid turnover of microtubules, the TOG/XMAP215–cyclin B1 interaction may be important for regulation of microtubule dynamics at mitosis. 相似文献
93.
Xiaoli Kong Yi Duan Yuting Sang Yaming Li Hanwen Zhang Yiran Liang Ying Liu Ning Zhang Qifeng Yang 《Journal of cellular physiology》2019,234(6):9105-9117
Rapid proliferation and metastasis of breast cancers resulted in poor prognosis in clinic. Recent studies have proved that long noncoding RNAs (lncRNAs) were involved in tumor progression. In this study, we aimed to determine the roles and mechanisms of lncRNA–cell division cycle 6 (CDC6) in regulating proliferation and metastasis of breast cancer. Clinically, lncRNA–CDC6 was highly expressed in tumor tissues and was positively correlated with clinical stages of breast cancers. Functionally, the ectopic expression of lncRNA–CDC6 promoted proliferation via regulation of G1 phase checkpoint, and further promoting the migration capability. Moreover, lncRNA–CDC6 could function as competitive endogenous RNA (ceRNA) via directly sponging of microRNA-215 (miR-215), which further regulating the expression of CDC6. Taken together, our results proved that lncRNA–CDC6 could function as ceRNA and promote the proliferation and metastasis of breast cancer cells, which provided a novel prognostic marker for breast cancers in clinic. 相似文献
94.
F Georges R Brousseau J Michniewicz G Prefontaine J Stawinski W Sung R Wu S A Narang 《Gene》1984,27(2):201-211
A 74-bp DNA sequence coding for the pre sequence of human preproinsulin and containing EcoRI termini was synthesized by the chemical enzymatic method, joined with previously synthesized proinsulin DNA, and cloned in the M 13mp8 vector. A clone pNB82 -121 was identified by DNA sequence which confirmed the correct orientation of the pre sequence to the proinsulin DNA. The EcoRI site at the junction of pre- and proinsulin DNA was eliminated by removing a triplet ATT using a synthetic 19-mer primer. To simplify preproinsulin isolation and to study its expression in the M 13 system, a 25-bp affinity leader sequence coding for (glu)7 was inserted at the remaining EcoRI site; this put the preproinsulin DNA in a correct reading frame with the AUG initiation codon of beta-galactosidase. Preproinsulin was expressed under lac promoter control as analyzed by a radioimmunoassay (RIA) against C-peptide. 相似文献
95.
Barbara De Meester Ruben Vanholme Lisanne de Vries Marlies Wouters Jan Van Doorsselaere Wout Boerjan 《The Plant journal : for cell and molecular biology》2021,108(3):752-765
Lignin is one of the main factors determining recalcitrance to processing of lignocellulosic biomass towards bio-based materials and fuels. Consequently, wood of plants engineered for low lignin content is typically more amenable to processing. However, lignin-modified plants often exhibit collapsed vessels and associated growth defects. Vessel-specific reintroduction of lignin biosynthesis in dwarfed low-lignin cinnamoyl-CoA reductase1 (ccr1) Arabidopsis mutants using the ProSNBE:AtCCR1 construct overcame the yield penalty while maintaining high saccharification yields, and showed that monolignols can be transported between the different xylem cells acting as ‘good neighbors’ in Arabidopsis. Here, we translated this research into the bio-energy crop poplar. By expressing ProSNBE:AtCCR1 into CRISPR/Cas9-generated ccr2 poplars, we aimed for vessel-specific lignin biosynthesis to: (i) achieve growth restoration while maintaining high saccharification yields; and (ii) study the existence of ‘good neighbors’ in poplar wood. Analyzing the resulting ccr2 ProSNBE:AtCCR1 poplars showed that vessels and rays act as good neighbors for lignification in poplar. If sufficient monolignols are produced by these cells, monolignols migrate over multiple cell layers, resulting in a restoration of the lignin amount to wild-type levels. If the supply of monolignols is limited, the monolignols are incorporated into the cell walls of the vessels and rays producing them and their adjoining cells resulting in fiber hypolignification. One such fiber-hypolignified line had 18% less lignin and, despite its small yield penalty, had an increase of up to 71% in sugar release on a plant base upon saccharification. 相似文献
96.
97.
Summary. Successful cryopreservation of plant shoot tips is dependent upon effective desiccation through osmotic or physical processes.
Microscopy techniques were used to determine the extent of cellular damage and plasmolysis that occurs in peppermint (Mentha × piperita) shoot tips during the process of cryopreservation, using the cryoprotectant plant vitrification solution 2 (PVS2) (30% glycerol,
15% dimethyl sulfoxide, 15% ethylene glycol, 0.4 M sucrose) prior to liquid-nitrogen exposure. The meristem cells were the
smallest and least plasmolyzed cell type of the shoot tips, while the large, older leaf and lower cortex cells were the most
damaged. When treated with cryoprotectant solutions, meristem cells exhibited concave plasmolysis, suggesting that this cell
type has a highly viscous protoplasm, and protoplasts have many cell wall attachment sites. Shoot tip cells were most severely
plasmolyzed after PVS2 treatment, liquid-nitrogen exposure, and warming in 1.2 M sucrose. Successful recovery may be dependent
upon surviving the plasmolytic conditions induced by warming and diluting treated shoot tips in 1.2 M sucrose solutions. In
peppermint shoot tips, clumps of young meristem or young leaf cells survive the cryopreservation process and regenerate plants
containing many shoots. Cryoprotective treatments that favor survival of small, meristematic cells and young leaf cells are
most likely to produce high survival rates after liquid-nitrogen exposure.
Correspondence and reprints: National Center for Genetic Resources Preservation, U.S. Department of Agriculture, 1111 S. Mason
Street, Fort Collins, CO 80521, U.S.A. 相似文献
98.
Annicchiarico P 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2007,114(4):647-657
This study is aimed at comparing wide- versus specific-adaptation strategies for lucerne in northern Italy on the basis of
actual dry matter yield gains over 12 harvests from phenotypic selection, assessing the value of specific genetic bases and
selecting environments for the contrasting subregion A (no drought stress/sandy-loam soil) and subregion C (summer drought
stress/silty-clay soil). A second aim is to investigate the adaptive responses of five sets of 18 half-sib progenies. The
following selected populations were evaluated along with five cultivars: GW–SW, GA–SA, GA–SC, GC–SC and GC–SA (where GW, GA
and GC are the genetic bases for wide adaptation, subregions A and C; SW, SA and SC are the selection environments for wide
adaptation, subregions A and C). The selection and test environments were four artificial environments created by the factorial
combination of two drought stress levels by two soil types. Two environments represented the subregions A and C whereas the
combination of the other two environments represented the intermediate subregion B. Genotype × environment interaction (P ≤ 0.001) due to both environmental factors and implying cross-over interaction between the contrasting subregions occurred
for the populations and the five selections. Specific genetic bases (GA and GC) implied gains in their target subregions of
5.2% for subregion A and 2.9% for subregion C compared with the widely adapted one (GW). The gain of SA (‘no stress/sandy-loam
soil’) over SC (‘stress/silty-clay soil’) decreased from subregion A (10.6%) through subregion C (1.7%) but exhibited an advantage
per se across environments of 5.4%. The best specific selections (GA–SA for subregions A and B; GC–SA for subregion C) implied
higher yields of 9.8% in subregion A and 6.5% in subregion C, and over twofold greater selection efficiency across the region,
relative to GW–SW. Half-sib progeny × artificial environment interaction (P ≤ 0.05) occurred in three sets of progenies whose parents belonged to cultivars with different or similar adaptation. 相似文献
99.
Insecticidal proteins are a potential resource to enhance resistance to insect pests in transgenic plants. Here, we describe
the generation and analysis of the apple cultivar ‘Royal Gala’ transgenic for Nicotiana alata (N. alata) proteinase inhibitor (PI) and the impact of this PI on the growth and development of the Epiphyas postvittiana (light-brown apple moth). A cDNA clone encoding a proteinase inhibitor precursor from N. alata (Na-PI) under the control of either a double 35S promoter or a promoter from a ribulose-1,5-bisphosphate carboxylase small
sub-unit gene (rbcS-E9 promoter) was stably incorporated into ‘Royal Gala’ apple using Agrobacterium-mediated transformation. A 40.3 kDa Na-PI precursor protein was expressed and correctly processed into 6-kDa proteinase inhibitors
in the leaves of transgenic apple lines. The 6-kDa polypeptides accumulated to levels of 0.05 and 0.1% of the total soluble
protein under the control of the rbc-E9 promoter and the double 35S promoter, respectively. Light-brown apple moth larvae fed with apple leaves expressing Na-PI
had significantly reduced body weight after 7 days of feeding and female pupae were 19–28% smaller than controls. In addition,
morphological changes such as pupal cases attached to the wing, deformed wings, deformed body shape, and pupal cases and curled
wings attached to a deformed body were observed in adults that developed from larvae fed with apple leaves expressing Na-PI,
when compared to larvae fed with the non-transformed apple leaves. 相似文献
100.
木质素是木材的重要组成成分,主要起机械支持、水分运输及防御病虫害等作用。4CL酶是控制木质素合成途径中的关键酶之一。利用PCR技术从84K杨幼叶cDNA中克隆得到Pag4CL3/4CL5基因,GenBank 登录号分别为MK183033(Pag4CL3)及MK183034(Pag4CL5)。利用生物信息学软件,对这两个基因的功能和特征进行分析。结果发现84K杨中4CL3/4CL5蛋白与毛果杨中4CL3/4CL5蛋白相似度高达97%;此外,均含有SSGTTGLPKGV和GEICIRG两个保守基序;亚细胞定位预测显示Pag4CL3/4CL5蛋白主要定位在内质网中,推测可能是一种膜蛋白;蛋白的亲水性预测Pag4CL3/4CL5均为亲水性蛋白。通过qRT-PCR分析Pag4CL3/4CL5在不同组织部位中的表达差异,结果发现Pag4CL3在叶及茎中表达量较高,在根和顶芽中表达量较低;Pag4CL5在叶及根中表达量较高,在茎和顶芽中表达量较低,两个同源基因表达具有组织部位的差异性。Pag4CL3和Pag4CL5可能在叶中共同行使功能,Pag4CL5主要在根中行使功能,Pag4CL3主要在茎中行使功能。 相似文献