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21.
The synthesis of polyfunctionalized delta-lactams as key intermediates of glycomimetics in the 2-acetamido-2-deoxy sugar series is presented. Starting from a chiral gamma-amino vinylic ester synthesized from Garner's aldehyde and after regioselective reduction, 1-azido-3-(N-tert-butyloxycarbonyl-2,2-dimethyloxazolidin-4-yl)-2-propene was obtained. Next, a cis-dihydroxylation reaction provided the protected D-xylitol and L-arabinitol azides. A simple protection-deprotection sequence, followed by an oxidation and a reductive cyclization, led to protected 2-amino-delta-lactams bearing a tert-butyloxycarbonyl group on the amine functionality. To explore the reactivity of such compounds, activation of the lactam into the corresponding thionolactam was performed. The resulting 2-amino-D-xylothionolactam derivative, a versatile intermediate, allowed access to a first generation of protected 2-amino-D-xylosamidoxime derivatives which are of interest as precursors of N-acetylhexosaminidase and N-acetylglucosaminyltransferase inhibitors. In this series of compounds, epimerization at C-2 was observed. AM(1) calculations performed on these analogs showed that they adopted a B(2,5) conformation and that the axial epimer was favored in the protected series whereas the equatorial epimer was preferred in the unprotected series. 相似文献
22.
Coulibaly I Noirot M Lorieux M Charrier A Hamon S Louarn J 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2002,105(6-7):994-999
Self-compatibility segregation was assessed in two successive backcross progenies originating from an interspecific cross between Coffea canephora (self-incompatible) and Coffea heterocalyx (self-compatible). After self- and cross-pollination, pollen tube behaviour in styles was observed under ultraviolet fluorescence microscopy and fruit-set was determined at harvesting time. Segregation ratios in the two progenies were consistent with monofactorial control of self-compatibility. Self-compatible plants exhibited higher fruit-set than self-incompatible ones in open-pollination conditions. Segregation of AFLP markers was scored in the first backcross progeny. By molecular linkage analysis, the S locus could be mapped to a short linkage group. 相似文献
23.
Identification and functional analysis of a naturally occurring E89K mutation in the ABCA1 gene of the WHAM chicken 总被引:1,自引:0,他引:1
Attie AD Hamon Y Brooks-Wilson AR Gray-Keller MP MacDonald ML Rigot V Tebon A Zhang LH Mulligan JD Singaraja RR Bitgood JJ Cook ME Kastelein JJ Chimini G Hayden MR 《Journal of lipid research》2002,43(10):1610-1617
The Wisconsin hypoalpha mutant (WHAM) chicken has a >90% reduction in plasma HDL due to hypercatabolism by the kidney of lipid-poor apoA-I. The WHAM chickens have a recessive white skin phenotype caused by a single-gene mutation that maps to the chicken Z-chromosome. This corresponds to human 9q31.1, a chromosomal segment that contains the ATP-binding cassette protein-1 (ABCA1) gene, which is mutated in Tangier Disease and familial hypoalphalipoproteinemia. Complete sequencing of the WHAM ABCA1 cDNA identified a missense mutation near the N-terminus of the protein (E89K). The substitution of this evolutionary conserved glutamate residue for lysine in the mouse ABCA1 transporter leads to complete loss of function, resulting principally from defective intracellular trafficking and very little ABCA1 reaching the plasma membrane. The WHAM chicken is a naturally occurring animal model for Tangier Disease. 相似文献
24.
25.
Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis 总被引:6,自引:0,他引:6
Chaix G Gerber S Razafimaharo V Vigneron P Verhaegen D Hamon S 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,107(4):705-712
Eucalyptus grandis has a mixed-mating reproductive system. Malagasy Eucalyptus seed orchards were established 15 years ago with two aims both based on panmixia: open-pollinated seed production and genetic improvement. The panmixia hypothesis has never been confirmed in the seed orchard. From a seedling seed-orchard stand comprising 349 trees and using data obtained with six selected microsatellite markers, paternity analysis was performed for 724 offspring collected on 30 adult trees. Paternity assignment, based on exclusion procedures and likelihood-ratio method, was achieved with high accuracy; the exclusion probability value was 0.997. The outcrossing rate was very high (96.7%). More than 50% of potential male trees (199 out of 349) in the seed orchard contributed to pollination for 440 offspring of 30 progenies (8.6% of the basic population). The pollination rate from outside the seed orchard was high (39.2%), but might be due to the small size of this seed orchard. This study showed that "panmixia-like pollination" can be assumed. 相似文献
26.
Akaffou DS Ky CL Barre P Hamon S Louarn J Noirot M 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2003,106(8):1486-1490
Fructification time was studied in the interspecific cross Coffea pseudozanguebariae x C. liberica var. Dewevrei (PSE x DEW). Parental species, F(1) hybrids and offspring of the first backcross generation (BC(1)), consisting of F(1) x PSE (BCPSE) and F(1) x DEW (BCDEW) plants, were observed. Fructification time can be split into two independent visual phases: the full-growth period, from blooming up to the end of fruit growth, and the maturation phase, defined by the green to red color change. Fructification time was found to be an additive trait. The full-growth period showed a bimodal distribution in the BCDEW hybrid, suggesting the involvement of Ft1, a major gene that was mapped on linkage group E. The main effects of Ft1 were to lower caffeine content and 100-seed weight, without any impact on chlorogenic acid, trigonelline and sucrose contents. Two molecular markers were identified that bracket Ft1 and which could be used for early marker-assisted selection. 相似文献
27.
Reciprocal interactions between central 5-HT system and hypothalamo-pituitary-adrenal (HPA) axis are of particular relevance with regard to depression, in which alterations of both systems have been evidenced. In order to further explore these interactions, two models of mutant mice have been used. They consisted of knock-out mice lacking the 5-HT transporter (5-HTT-/-) and of transgenic mice with impaired glucocorticoid receptor (GR-i) expression. Under control conditions. the functional properties of 5-HT(1A) autoreceptors in GR-i mice were as in their paired wild-type. However, both chronic stress and long term treatment with fluoxetine induced abnormal adaptive changes in 5-HT(1A) autoreceptor functioning in GR-i mice. On the other hand, a marked desensitization of 5-HT(1A) autoreceptors was found in 5-HTT-/- mice as compared with paired wild-type animals, and this phenomenon was further enhanced by exposure to stressful conditions. These data show that alterations of HPA axis at the gene level has consequences on 5-HT neurotransmission, and reciprocally, that 5-HTT knock-out affects HPA-dependent responses to stress. 相似文献
28.
P. Barre S. Akaffou J. Louarn A. Charrier S. Hamon M. Noirot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,96(2):306-311
Coffee species originating from Africa, in particular the two major cultivated species C. arabica and C. canephora, usually contain caffeine in their beans, whereas almost all Malagasy coffee species are caffeine-free. However, one wild
coffee species C. pseudozanguebariae, collected near the coast in south Kenya, is also caffeine-free. Beans of this species contain a specific heteroside diterpene
(hereinafter referred to simply as heteroside) and give a bitter coffee beverage. We have investigated the inheritance of
the caffeine and heteroside contents in the first and second generations of an interspecific cross between C. pseudozanguebariae and C. liberica var. dewevrei, for which the caffeine content is about 1% dmb (dry matter basis). The caffeine content of F1 hybrids (0.2% dmb) was lower than the parental average (0.47% dmb). Caffeine and heteroside contents appeared to be under
polygenic control with a strong genetic effect. Nevertheless, one major gene with two alleles seemed to be involved in the
control of both compounds. Absence of caffeine was apparently controlled by one recessive gene. Heteroside content seemed
to be controlled by one co-dominant gene, heterozygotes being intermediate between the two different groups of homozygotes.
Received: 15 September 1997 / Accepted: 6 October 1997 相似文献
29.
J.-F. Rami P. Dufour G. Trouche G. Fliedel C. Mestres F. Davrieux P. Blanchard P. Hamon 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(4):605-616
Quantitative trait loci (QTLs) for grain quality, yield components and other traits were investigated in two Sorghum caudatum×guinea
recombinant inbred line (RIL) populations. A total of 16 traits were evaluated (plant height, panicle length, panicle compactness,
number of kernels/panicle, thousand-kernel weight, kernel weight/panicle, threshing percentage, dehulling yield, kernel flouriness,
kernel friability, kernel hardness, amylose content, protein content, lipid content, germination rate and molds during germination
and after harvest) and related to two 113- and 100-point base genetic maps using simple (SIM) and composite (CIM) interval
mapping. The number, effects and relative position of QTLs detected in both populations were generally in agreement with the
distributions, heritabilities and correlations among traits. Several chromosomal segments markedly affected multiple traits
and were suspected of harbouring major genes. The positions of these QTLs are discussed in relation to previously reported
studies on sorghum and other grasses. Many QTLs, depending on their relative effects and position, could be used as targets
for marker-assisted selection and provide an opportunity for accelerating breeding programmes.
Received: 14 February 1998 / Accepted: 4 March 1998 相似文献
30.
I. Métais C. Aubry B. Hamon D. Peltier R. Jalouzot 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1998,97(1-2):232-237
We describe the cloning and the characterization of a 130-bp DNA fragment, called OPG9-130, amplified from bean (Phaseolus vulgaris L.) genomic DNA. This fragment corresponds to a minisatellite DNA sequence containing seven repeats of 15 bp which differ
slightly from each other in their sequence. Southern analysis showed that the core sequence of 15 bp is repeated in clusters
dispersed throughout the genome. The use of this fragment as a probe allowed us to identify common bean lines by their DNA
fingerprints. We suggest that OPG9-130 will be useful for line identification as well as for the analysis of genetic relatedness
between bean species and lines.
Received: 14 February 1998 / Accepted: 10 February 1998 相似文献