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131.
132.
Fine Mapping QTL for Drought Resistance Traits in Rice (<Emphasis Type="Italic">Oryza sativa</Emphasis> L.) Using Bulk Segregant Analysis 总被引:1,自引:0,他引:1
Salunkhe AS Poornima R Prince KS Kanagaraj P Sheeba JA Amudha K Suji KK Senthil A Babu RC 《Molecular biotechnology》2011,49(1):90-95
Drought stress is a major limitation to rice (Oryza sativa L.) yields and its stability, especially in rainfed conditions. Developing rice cultivars with inherent capacity to withstand
drought stress would improve rainfed rice production. Mapping quantitative trait loci (QTLs) linked to drought resistance
traits will help to develop rice cultivars suitable for water-limited environments through molecular marker-assisted selection
(MAS) strategy. However, QTL mapping is usually carried out by genotyping large number of progenies, which is labour-intensive,
time-consuming and cost-ineffective. Bulk segregant analysis (BSA) serves as an affordable strategy for mapping large effect
QTLs by genotyping only the extreme phenotypes instead of the entire mapping population. We have previously mapped a QTL linked
to leaf rolling and leaf drying in recombinant inbred (RI) lines derived from two locally adapted indica rice ecotypes viz., IR20/Nootripathu using BSA. Fine mapping the QTL will facilitate its application in MAS. BSA was done
by bulking DNA of 10 drought-resistant and 12 drought-sensitive RI lines. Out of 343 rice microsatellites markers genotyped,
RM8085 co-segregated among the RI lines constituting the respective bulks. RM8085 was mapped in the middle of the QTL region
on chromosome 1 previously identified in these RI lines thus reducing the QTL interval from 7.9 to 3.8 cM. Further, the study
showed that the region, RM212–RM302–RM8085–RM3825 on chromosome 1, harbours large effect QTLs for drought-resistance traits
across several genetic backgrounds in rice. Thus, the QTL may be useful for drought resistance improvement in rice through
MAS and map-based cloning. 相似文献
133.
Gao S Babu R Lu Y Martinez C Hao Z Krivanek AF Wang J Rong T Crouch J Xu Y 《PloS one》2011,6(1):e16101
Development of a seed DNA-based genotyping system for marker-assisted selection (MAS) has provided a novel opportunity for understanding aberrant reproductive phenomena such as hetero-fertilization (HF) by observing the mismatch of endosperm and leaf genotypes in monocot species. In contrast to conventional approaches using specific morphological markers, this approach can be used for any population derived from diverse parental genotypes. A large-scale experiment was implemented using seven F(2) populations and four three-way cross populations, each with 534 to 1024 individuals. The frequency of HF within these populations ranged from 0.14% to 3.12%, with an average of 1.46%. The highest frequency of HF in both types of population was contributed by the pollen gametes. Using three-way crosses allowed, for the first time, detection of the HF contributed by maternal gametes, albeit at very low frequency (0.14%-0.65%). Four HF events identified from each of two F(2) populations were tested and confirmed using 1032 single nucleotide polymorphic markers. This analysis indicated that only 50% of polymorphic markers can detect a known HF event, and thus the real HF frequency can be inferred by doubling the estimate obtained from using only one polymorphic marker. As expected, 99% of the HF events can be detected by using seven independent markers in combination. Although seed DNA-based analysis may wrongly predict plant genotypes due to the mismatch of endosperm and leaf DNA caused by HF, the relatively low HF frequencies revealed with diverse germplasm in this study indicates that the effect on the accuracy of MAS is limited. In addition, comparative endosperm and leaf DNA analysis of specific genetic stocks could be useful for revealing the relationships among various aberrant fertilization phenomena including haploidy and apomixis. 相似文献
134.
Parkinson's disease (PD) is linked to the formation of insoluble fibrillar aggregates of the presynaptic protein α-Synuclein (αS) in neurons. The appearance of such aggregates coincides with severe motor deficits in human patients. These deficits are often preceded by non-motor symptoms such as sleep-related problems in the patients. PD-like motor deficits can be recapitulated in model organisms such as Drosophila melanogaster when αS is pan-neurally expressed. Interestingly, both these deficits are more severe when αS mutants with reduced aggregation properties are expressed in flies. This indicates that that αS aggregation is not the primary cause of the PD-like motor symptoms. Here we describe a model for PD in Drosophila which utilizes the targeted expression of αS mutants in a subset of dopadecarboxylase expressing serotonergic and dopaminergic (DA) neurons. Our results show that targeted expression of pre-fibrillar αS mutants not only recapitulates PD-like motor symptoms but also the preceding non-motor symptoms such as an abnormal sleep-like behavior, altered locomotor activity and abnormal circadian periodicity. Further, the results suggest that the observed non-motor symptoms in flies are caused by an early impairment of neuronal functions rather than by the loss of neurons due to cell death. 相似文献
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137.
Sundar Babu Sakya Mohapatra Leonid Zubkov Sreekant Murthy Elisabeth Papazoglou 《Biosensors & bioelectronics》2009,24(12):3467-3474
The development of a simple and inexpensive quantum dot based immunoassay for detecting myeloperoxidase (MPO) in stool samples is reported (QLISA). The method developed utilizes readily available polymethylmethacrylate (PMMA) microcapillaries as substrates for performing the sandwich assay. High power (80 mW) and low power (10 mW) UV-LEDs were tested for their efficiency in maximizing detection sensitivity in a waveguide illumination or a side illumination mode. The results obtained indicate that both waveguide and side illumination modes can be employed for detecting MPO down to 15 ng/mL, however the high power LED in a side illumination mode improves sensitivity and simplifies the data acquisition process. The protocol and sensor robustness was evaluated with animal stool samples spiked with MPO and the results indicate that the sensitivity of detection is not compromised when used in stool samples. The effect of the ionic strength of the environment on the fluorescence stability of quantum dots was evaluated and found to affect the assay only if long imaging times are employed. Replacing the buffer with glycerol during imaging increased the fluorescence intensity of quantum dots while significantly minimized the loss in intensity even after 2 h. 相似文献
138.
139.
Exogenous supply of pantoyl lactone to excised leaves increases their pantothenate levels 总被引:1,自引:0,他引:1
BACKGROUND AND AIMS: All plants synthesize pantothenate but its synthesis and regulation are not well understood. The aim of this work is to study the effect of exogenous supply of precursor compounds on pantothenate levels in leaves. METHODS: Precursor compounds were supplied in solution to excised leaves and the pantothenate content was measured using a microbial method. KEY RESULTS: Pantothenate levels in excised leaves of Limonium latifolium, tomato (Lycopersicon esculentum), bean (Phaseolus vulgaris) and grapefruit (Citrus x paradisi) were examined following an exogenous supply of the precursor compounds pantoyl lactone or beta-alanine. Significantly higher levels of extractable pantothenate were found when pantoyl lactone was supplied, but not when beta-alanine was supplied despite a measurable uptake of beta-alanine into the leaf. CONCLUSIONS: The results suggested that the pantoate supply may be rate-limiting or regulating pantothenate synthesis in leaves. 相似文献
140.