全文获取类型
收费全文 | 138篇 |
免费 | 12篇 |
出版年
2021年 | 1篇 |
2020年 | 1篇 |
2018年 | 4篇 |
2017年 | 4篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 13篇 |
2012年 | 9篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 2篇 |
2008年 | 9篇 |
2007年 | 7篇 |
2006年 | 8篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 9篇 |
2002年 | 10篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1992年 | 3篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1981年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有150条查询结果,搜索用时 15 毫秒
1.
Structure-activity relationship of swainsonine. Inhibition of human alpha-mannosidases by swainsonine analogues. 总被引:1,自引:1,他引:0
I Cenci di Bello G Fleet S K Namgoong K Tadano B Winchester 《The Biochemical journal》1989,259(3):855-861
The inhibitory properties of a series of synthetic epimers and analogues of swainsonine towards the multiple forms of human alpha-mannosidases were studied in vitro and in cells in culture. Of the five epimers tested, only the 8a-epimer and 8,8a-diepimer of swainsonine were specific and competitive inhibitors (Ki values of 7.5 x 10(-5) and 2 x 10(-6) M respectively) of lysosomal alpha-mannosidases in vitro and induced storage of mannose-rich oligosaccharides in human fibroblasts in culture. The structures of these storage products indicated that processing alpha-mannosidases had also been inhibited. This was consistent with the observed inhibition in vitro of these enzymes by these compounds. In contrast, the 8-epimer, 1,8-diepimer and 2,8a-diepimer of swainsonine had no appreciable effect on any alpha-mannosidases. The corresponding open-chain analogues of swainsonine, namely 1,4-dideoxy-1,4-imino-D-mannitol, of the 8a-epimer, namely 1,4-dideoxy-1,4-imino-D-talitol, and of the 8,8a-diepimer, namely 1,4-dideoxy-1,4-imino-L-allitol, were weaker competitive inhibitors of lysosomal alpha-mannosidase, with Ki values of 1.3 x 10(-5), 1.2 x 10(-4) and 1.2 x 10(-4) M respectively. These analogues also proved less effective at inducing oligosaccharide accumulation and in disturbing glycoprotein processing. These compounds offer the opportunity to determine which alterations in the chirality of the swainsonine molecule affect its inhibitory specificity. A comparison of their biological activities has identified reagents that will be useful for studying steps in the biosynthesis and catabolism of glycoproteins and that may be of potential value in chemotherapy. 相似文献
2.
E. Nenz F. Pupilli F. Paolocci F. Damiani C. A. Cenci S. Arcioni 《Plant Cell, Tissue and Organ Culture》1996,45(2):145-152
Culture conditions have been established for callus induction and growth from different explants in L. angustissimus L. Calli were obtained from hypocotyls, leaves, stems, cotyledons and roots cultured on media containing 2,4-dichlorophenoxyacetic acid or -naphthaleneacetic acid with kinetin, N6 – 2 or benzyladenine in different combinations and concentrations. Only those calli induced in presence of -naphthaleneacetic acid with benzyladenine or kinetin produced shoots. Calli induced from hypocotyl explants were the most efficient in regeneration of shoots. Transformation with an Agrobacterium rhizogenes binary vector carrying the plasmid pBI 121.1 is reported. The percentage of cotransformation was estimated by testing GUS activity in hairy roots. The integration of Ri T-DNA and the NPTII gene in transformed plants was confirmed by molecular analyses and in vitro culture of transgenic tissues in the presence of kanamycin.Abbreviations BA
benzyladenine
- 2,4-d
2,4-dichlorophenoxyacetic acid
- 1AA
indole-3-acetic acid
- NAA
-naphthaleneacetic acid
- 2iP
N6 – 2
- PA
proanthocyanidins
- NOS
nopaline synthase
- NI TII
neomycin phosphotransferase
- GUS
-glucuronidase
- CaMV
cauliflower mosaic virus 相似文献
3.
G. Caldini G. Cenci R. Manenti G. Morozzi 《Applied microbiology and biotechnology》1995,44(1-2):225-229
A Pseudomonas fluorescens strain isolated from exhausted-oil-polluted soil was selected for its ability to grow on and degrade chrysene as a sole carbon source. The same strain was able to grow on and degrade benz[a]anthracene, benzo[b]naphthothiophene, but not benz[a]acridine. After 2 days of incubation on a mineral medium supplemented with chrysene at 1 g/ml, reached by adding the Polynuclear aromatic hydrocarbon dissolved in a water-miscible solvent to the medium, the cell number had increased by 102–103. The biodegradation rate followed first-order kinetics and at its maximum value was independent of substrate concentration, as happens when the substrates are solubilized. 相似文献
4.
We have identified in plasma cells a novel ATG5-dependent selective negative control on the secretory pathway, which restricts antibody production, sustaining energy metabolism. Revealing new immune functions, autophagy is required in vivo for antibody responses and to maintain the memory plasma cell compartment. 相似文献
5.
Francesca Cipressa Sabrina Romano Silvia Centonze Petra I. zur Lage Fiammetta Vernì Patrizio Dimitri Maurizio Gatti Giovanni Cenci 《Genetics》2013,195(1):147-158
Drosophila telomeres are elongated by the transposition of telomere-specific retrotransposons rather than telomerase activity. Proximal to the terminal transposon array, Drosophila chromosomes contain several kilobases of a complex satellite DNA termed telomere-associated sequences (TASs). Reporter genes inserted into or next to the TAS are silenced through a mechanism called telomere position effect (TPE). TPE is reminiscent of the position effect variegation (PEV) induced by Drosophila constitutive heterochromatin. However, most genes that modulate PEV have no effect on TPE, and systematic searches for TPE modifiers have so far identified only a few dominant suppressors. Surprisingly, only a few of the genes required to prevent telomere fusion have been tested for their effect on TPE. Here, we show that with the exception of the effete (eff; also called UbcD1) mutant alleles, none of the tested mutations at the other telomere fusion genes affects TPE. We also found that mutations in eff, which encodes a class I ubiquitin-conjugating enzyme, act as suppressors of PEV. Thus, eff is one of the rare genes that can modulate both TPE and PEV. Immunolocalization experiments showed that Eff is a major constituent of polytene chromosomes. Eff is enriched at several euchromatic bands and interbands, the TAS regions, and the chromocenter. Our results suggest that Eff associates with different types of chromatin affecting their abilities to regulate gene expression. 相似文献
6.
7.
Blanco A Simeone R Cenci A Gadaleta A Tanzarella OA Porceddu E Salvi S Tuberosa R Figliuolo G Spagnoletti P Röder MS Korzun V 《Cellular & molecular biology letters》2004,9(3):529-541
A set of recombinant inbred lines (RIL) derived from a cross between the cultivar Messapia of durum wheat (Triticum turgidum var. durum) and the accession MG4343 of T. turgidum var. dicoccoides was analysed to increase the number of assigned markers and the resolution of the previously constructed genetic linkage map. An updated map of the durum wheat genome consisting of 458 loci was constructed. These loci include 261 Restriction Fragment Length Polymorphisms (RFLPs), 91 microsatellites (Simple Sequence Repeats, SSRs), 87 Amplified Fragment Length Polymorphisms (AFLPs), two ribosomal genes, and nine biochemical (seven seed storage proteins and two isozymes) and eight morphological markers. The loci were mapped on all 14 chromosomes of the A and B genomes, and covered a total distance of 3038.4 cM with an average distance of 6.7 cM between adjacent markers. The molecular markers were evenly distributed between the A and the B genomes (240 and 218 markers, respectively). An additional forty loci (8.8%) could not be assigned to a specific linkage group. A fraction (16.4%) of the markers significantly deviated from the expected Mendelian ratios; clusters of loci showing distorted segregation were found on the 1B, 2A, 2B, 3A, 4A, 7A and 7B chromosomes. The genetic lengths of the chromosomes range from 148.8 cM (chromosome 6B) to 318.0 cM (chromosome 2B) and approximately concur with their physical lengths. Chromosome 2B has the largest number of markers (47), while the chromosomes with the fewest markers are 3A and 6B (23). There are two gaps larger than 40 cM on chromosomes 2A and 3B. The durum wheat map was compared with the published maps of bread and durum wheats; the order of most common RFLP and SSR markers on the 14 chromosomes of the A and B genomes were nearly identical. A core-map can be extracted from the high-density Messapia x dicoccoides map and a subset of uniformly distributed markers can be used to detect and map quantitative trait loci. 相似文献
8.
Borges E Vuaden FC Cognato Gde P Fauth Mda G Bonan CD Turcato G Rossi IC Dias RD 《Journal of experimental zoology. Part A, Comparative experimental biology》2004,301(11):891-897
In the present study, the glucose concentration in the haemolymph and glycogen levels were determined in the various body parts of the Helix aspersa snail after feeding lettuce ad libitum and after various periods of starvation. To characterize the effect of starvation on nucleotidase activity, enzyme assays were performed on membranes of the nervous ganglia and digestive gland. Results demonstrated the maintenance of the haemolymph glucose concentration for up to 30 days of starvation, probably due to the consumption of glycogen from the mantle. In the nervous ganglia, depletion of glycogen occurs progressively during the different periods of starvation. No significant changes were observed on ATP and ADP hydrolysis in the membranes of nervous ganglia and no alterations in Ca2+ -ATPase and Mg2+ -ATPase occurred in the membranes of the digestive gland of H. aspersa during the different periods of starvation. Although there were no changes in the enzyme activities during starvation, they could be modulated by effectors in situ with concomitant changes in products/reactants during starvation. 相似文献
9.
Barren, the Drosophila homolog of XCAP-H, is one of three non-SMC subunits of condensin, a conserved 13S multiprotein complex required for chromosome condensation. Mutations in barren (barr) were originally shown to affect sister-chromatid separation during mitosis 16 of the Drosophila embryo, whereas condensation defects were not detected. In contrast, mutations in yeast homologs of barren result in defective mitotic chromosome condensation as well as irregular chromatid separation. We have used double-stranded RNA-mediated interference (RNAi) to deplete Barren in Drosophila S2 cells. Our analyses indicate that inactivation of barr leads to extensive chromosome condensation and disrupts chromatid segregation. 相似文献
10.
Giorgia M Siriaco Giovanni Cenci Abdelali Haoudi Larry E Champion Chun Zhou Maurizio Gatti James M Mason 《Genetics》2002,160(1):235-245
In most eukaryotes telomeres are extended by telomerase. Drosophila melanogaster, however, lacks telomerase, and telomere-specific non-LTR retrotransposons, HeT-A and TART, transpose specifically to chromosome ends. A Drosophila strain, Gaiano, that has long telomeres has been identified. We extracted the major Gaiano chromosomes into an Oregon-R genetic background and examined the resulting stocks after 60 generations. In situ hybridization using HeT-A and TART sequences showed that, in stocks carrying either the X or the second chromosome from Gaiano, only the Gaiano-derived chromosomes display long telomeres. However, in stocks carrying the Gaiano third chromosome, all telomeres are substantially elongated, indicating that the Gaiano chromosome 3 carries a factor that increases HeT-A and TART addition to the telomeres. We show that this factor, termed Telomere elongation (Tel), is dominant and localizes as a single unit to 69 on the genetic map. The long telomeres tend to associate with each other in both polytene and mitotic cells. These associations depend on telomere length rather than the presence of Tel. Associations between metaphase chromosomes are resolved during anaphase, suggesting that they are mediated by either proteinaceous links or DNA hydrogen bonding, rather than covalent DNA-DNA bonds. 相似文献