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821.
822.
Sajjad Hussain Mark Slevin Nessar Ahmed David West Muhammad Iqbal Choudhary Humera Naz John Gaffney 《BMC cell biology》2009,10(1):30
Background
Angiogenesis, the growth of new blood vessels from the pre-existing vasculature is associated with pathological processes, in particular tumour development, and is a target for the development of new therapies. We have investigated the anti-angiogenic potential of two naturally occurring stilbene glycosides (compounds 1 and 2) isolated from the medicinal plant Boswellia papyriferai using large and smallvessel-derived endothelial cells. Compound 1 (trans-4',5'-dihydroxy-3-methoxystilbene-5-O-{α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→6)}-β-D-glucopyranoside was the more hydrophilic and inhibited FGF-2-induced proliferation, wound healing, invasion in Matrigel, tube formation and angiogenesis in large and small vessel-derived endothelial cells and also in the chick chorioallantoic membrane assay. Using a binding assay we were able to show compound 1 reduced binding of FGF-2 to fibroblast growth factor receptors-1 and -2. In all cases the concentration of compound 1 which caused 50% inhibition (IC50) was determined. The effect of compound 1 on EGF and VEGF-induced proliferation was also investigated. 相似文献823.
A.K. Choudhary 《Letters in applied microbiology》1992,14(4):143-147
The co-inhabiting mycoflora with Aspergillus flavus observed on individual maize kernels was evaluated for its influence on aflatoxin synthesis. All 13 types of associations of different fungal species inhibited aflatoxin B1 and G1 production at different levels (34·3–100%). Inhibition of radial growth of A. flavus by Fusarium moniliforme (59·8%), Trichoderma viride (72·5%) and Rhizopus nigricans (42%) could be directly correlated to the per cent inhibition of aflatoxin production. High levels of inhibition of aflatoxin elaboration were noted in competition of A. flavus with other toxigenic moulds. 相似文献
824.
7 varieties of mustards were cultivated in statistically designed field during 1988 through 1989 and 1989 through 1990 crops in order to ascertain the resistant or less susceptible varieties for aflatoxin elaboration. Under field condition, none of the varieties of mustard was found to be resistant. Maximum aflatoxin contamination was observed in the late planting time (15 th November) crops. Insect (Lipaphis erysime) incidence had significant negative correlation (r=?0.9354) with the yield (Q/hectare) while it had significant positive correlation (r=0.5705) with aflatoxin contamination. 相似文献
825.
826.
827.
B. R. Choudhary P. Joshi K. Singh 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2000,101(5-6):990-999
Amphidiploid Raphanofortii was synthesized by colchicinization of the F1 hybrid Brassica tournefortii (TT, 2n = 20)×Raphanus caudatus (RR, 2n = 18). The crossability between these two species, and the cytomorphology of the F1 plants and the amphidiploids were investigated. Intergeneric hybrids between the species were obtained only when B. tournefortii was involved as female parent. The hybrid plants were intermediate for most of the morphological attributes and showed very
low pollen fertility compared to the parents. Although a majority of the pollen mother cells of the dihaploid hybrid (TR,
2n = 19) harboured univalents, a maximum of six bivalents were also observed. Of the 37 colchicine-treated F1 plants analyzed cytologically, 21 were found to be true amphidiploids (2n = 38), whereas seven were mixoploids. Meiosis in
the amphidiploids was characterized by the occurrence of 19 bivalents, though multivalents and univalents were also observed
in a few cells. Most of the amphidiploid plants exhibited a fairly high pollen and seed fertility, which was further enhanced
with the advancement of generations. Out of 69 plants investigated in the A2 generation, 64 were euploids while the remaining five were aneuploids (2n = 36, 37, 39, 40 and 42). The newly synthesized
Raphanofortii has great potential as a new commercial crop, as well as a bridge species for the transfer of economically important attributes
of both the species to other Brassicas.
Received: 2 November 1999 / Accepted: 26 March 2000 相似文献
828.
829.
C4 photosynthesis is thought to be an adaptation to warm environments, involving complex changes in the expression of genes governing photosynthesis, intermediary metabolism, and leaf anatomy and histology. Such complexity should be difficult to evolve, yet the pathway has arisen multiple times in the history of the flowering plants and at least four times in the grass family alone. We have used immunolocalization techniques to compare photosynthetic gene expression across all four origins, to determine which genetic changes occur in parallel and which are unique to a particular lineage. The only gene expression patterns common to all origins of the pathway are up-regulation of PEP carboxylase and down-regulation of RuBisCO in mesophyll cells. Both NAD-malic enzyme and NADP-malic enzyme are expressed in bundle sheaths. Expression patterns of light-harvesting chlorophyll a/b binding proteins and pyruvate orthophosphate dikinase appear to be lineage specific, and may be localized to bundle sheaths or to mesophyll or expressed throughout the photosynthetic tissue of the leaf. We suggest that future studies of parallel origin of the C4 pathway concentrate on regulation of the two carboxylases, as well as the increased density of vascular tissue, which is the only histological characteristic common to all origins of the pathway. 相似文献
830.
Development of chickpea EST-SSR markers and analysis of allelic variation across related species 总被引:1,自引:0,他引:1
Shalu Choudhary Niroj Kumar Sethy Bhumika Shokeen Sabhyata Bhatia 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》2009,118(3):591-608
Despite chickpea being the third important grain legume, there is a limited availability of genomic resources, especially
of the expressed sequence tag (EST)-based markers. In this study, we generated 822 chickpea ESTs from immature seeds as well
as exploited 1,309 ESTs from the chickpea database, thus utilizing a total of 2,131 EST sequences for development of functional
EST-SSR markers. Two hundred and forty-six simple sequence repeat (SSR) motifs were identified from which 183 primer pairs
were designed and 60 validated as functional markers. Genetic diversity analysis across 30 chickpea accessions revealed ten
markers to be polymorphic producing a total of 29 alleles and an observed heterozygosity average of 0.16 thereby exhibiting
low levels of intra-specific polymorphism. However, the markers exhibited high cross-species transferability ranging from
68.3 to 96.6% across the six annual Cicer species and from 29.4 to 61.7% across the seven legume genera. Sequence analysis of size variant amplicons from various species
revealed that size polymorphism was due to multiple events such as copy number variation, point mutations and insertions/deletions
in the microsatellite repeat as well as in the flanking regions. Interestingly, a wide prevalence of crossability-group-specific
sequence variations were observed among Cicer species that were phylogenetically informative. The neighbor joining dendrogram clearly separated the chickpea cultivars
from the wild Cicer and validated the proximity of C. judaicum with C. pinnatifidum. Hence, this study for the first time provides an insight into the distribution of SSRs in the chickpea transcribed regions
and also demonstrates the development and utilization of genic-SSRs. In addition to proving their suitability for genetic
diversity analysis, their high rates of transferability also proved their potential for comparative genomic studies and for
following gene introgressions and evolution in wild species, which constitute the valuable secondary genepool in chickpea.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献