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101.
Walter Hellmich 《Development genes and evolution》1930,121(1-2):135-203
Ohne Zusammenfassung 相似文献
102.
Romeis J Bartsch D Bigler F Candolfi MP Gielkens MM Hartley SE Hellmich RL Huesing JE Jepson PC Layton R Quemada H Raybould A Rose RI Schiemann J Sears MK Shelton AM Sweet J Vaituzis Z Wolt JD 《Nature biotechnology》2008,26(2):203-208
An international initiative is developing a scientifically rigorous approach to evaluate the potential risks to nontarget arthropods (NTAs) posed by insect-resistant, genetically modified (IRGM) crops. It adapts the tiered approach to risk assessment that is used internationally within regulatory toxicology and environmental sciences. The approach focuses on the formulation and testing of clearly stated risk hypotheses, making maximum use of available data and using formal decision guidelines to progress between testing stages (or tiers). It is intended to provide guidance to regulatory agencies that are currently developing their own NTA risk assessment guidelines for IRGM crops and to help harmonize regulatory requirements between different countries and different regions of the world. 相似文献
103.
Seeds of change: corn seed mixtures for resistance management and integrated pest management 总被引:3,自引:0,他引:3
Onstad DW Mitchell PD Hurley TM Lundgren JG Porter RP Krupke CH Spencer JL DiFonzo CD Baute TS Hellmich RL Buschman LL Hutchison WD Tooker JF 《Journal of economic entomology》2011,104(2):343-352
The use of mixtures of transgenic insecticidal seed and nontransgenic seed to provide an in-field refuge for susceptible insects in insect-resistance-management (IRM) plans has been considered for at least two decades. However, the U.S. Environmental Protection Agency has only recently authorized the practice. This commentary explores issues that regulators, industry, and other stakeholders should consider as the use of biotechnology increases and seed mixtures are implemented as a major tactic for IRM. We discuss how block refuges and seed mixtures in transgenic insecticidal corn, Zea mays L., production will influence integrated pest management (IPM) and the evolution of pest resistance. We conclude that seed mixtures will make pest monitoring more difficult and that seed mixtures may make IRM riskier because of larval behavior and greater adoption of insecticidal corn. Conversely, block refuges present a different suite of risks because of adult pest behavior and the lower compliance with IRM rules expected from farmers. It is likely that secondary pests not targeted by the insecticidal corn as well as natural enemies will respond differently to block refuges and seed mixtures. 相似文献
104.
Coates BS Sumerford DV Lopez MD Wang H Fraser LM Kroemer JA Spencer T Kim KS Abel CA Hellmich RL Siegfried BD 《Genetica》2011,139(8):961-972
The European corn borer, Ostrinia nubilalis (Lepidoptera: Crambidae), is an introduced crop pest in North America that causes major damage to corn and reduces yield of food, feed, and biofuel materials. The Cry1F toxin from Bacillus thuringiensis (Bt) expressed in transgenic hybrid corn is highly toxic to O. nubilalis larvae and effective in minimizing feeding damage. A laboratory colony of O. nubilalis was selected for high levels of Cry1F resistance (>12,000-fold compared to susceptible larvae) and is capable of survival on transgenic hybrid corn. Genetic linkage maps with segregating AFLP markers show that the Cry1F resistance trait is controlled by a single quantitative trait locus (QTL) on linkage group 12. The map position of single nucleotide polymorphism (SNP) markers indicated that midgut Bt toxin-receptor genes, alkaline phosphatase, aminopeptidase N, and cadherin, are not linked with the Cry1F QTL. Evidence suggests that genes within this genome interval may give rise to a novel Bt toxin resistance trait for Lepidoptera that appears independent of known receptor-based mechanisms of resistance. 相似文献
105.
While micro-FE simulations have become a standard tool in computational biomechanics, the choice of appropriate material properties is still a relevant topic, typically involving empirical grey value-to-elastic modulus relations. We here derive the voxel-specific volume fractions of mineral, collagen, and water, from tissue-independent bilinear relations between mineral and collagen content in extracellular bone tissue (J. Theor. Biol. 287: 115, 2011), and from the measured X-ray attenuation information quantified in terms of grey values. The aforementioned volume fractions enter a micromechanics representation of bone tissue, as to deliver voxel-specific stiffness tensors. In order to check the relevance of this strategy, we convert a micro Computer Tomograph of a mouse femur into a regular Finite Element mesh, apply forces related to the dead load of a standing mouse, and then compare simulation results based on voxel-specific heterogeneous elastic properties to results based on homogeneous elastic properties related to the spatial average over the solid bone matrix compartment, of the X-ray attenuation coefficients. The element-specific strain energy density illustrates that use of homogeneous elastic properties implies overestimation of the organ stiffness. Moreover, the simulation reveals large tensile normal stresses throughout the femur neck, which may explain the mouse femur neck's trabecular morphology being quite different from the human case, where the femur neck bears compressive forces and bending moments. 相似文献
106.
Decreased larval feeding and weight of the monarch butterfly, Danaus plexippus L., have been detected after 4 d of exposure in the laboratory to a high density of Bacillus thuringiensis (Bt)-expressing anthers. One hypothesis is that larvae exposed to Bt anthers exhibit increased wandering, resulting in less feeding and lower weight gain. To test this hypothesis, 2-d-old monarch butterfly larvae exposed to milkweed leaf disks with no anthers, anthers that express Bt (Cry1Ab, event MON810), or other non-Bt anthers were observed using a video-tracking system. As had been shown in previous studies, larvae exposed to Bt anthers fed less and gained less weight than larvae exposed to non-Bt or no anthers, yet there was no evidence of feeding on anthers. Total distance moved, maximum displacement from release point, percentage of time spent moving or near anthers, or mean turn angle did not differ across treatments. However, larvae exposed to Bt anthers spent more time off milkweed leaf disks than those exposed to no anthers and were more likely to move off the leaf than larvae exposed to non-Bt anthers. Results suggest that larvae exposed to Bt anthers behave differently and that ingestion may not be the only way Bt can affect nontarget insects like the monarch butterfly. 相似文献
107.
Bacillus thuringiensis plants expressing Cry1Ac,Cry2Ab and Cry1F are not toxic to the assassin bug,Zelus renardii 下载免费PDF全文
H.‐H. Su J.‐C. Tian S. E. Naranjo J. Romeis R. L. Hellmich A. M. Shelton 《Journal of Applied Entomology》2015,139(1-2):23-30
Cotton‐ and maize‐producing insecticidal crystal (Cry) proteins from the bacterium, Bacillus thuringiensis (Bt), have been commercialized since 1996. Bt plants are subjected to environmental risk assessments for non‐target organisms, including natural enemies that suppress pest populations. Here, we used Cry1F‐resistant Spodoptera frugiperda (J.E. Smith) and Cry1Ac and Cry2Ab‐resistant Trichoplusia ni (Hübner) as prey for the assassin bug, Zelus renardii (Kolenati), a common predator in maize and cotton fields. In tritrophic studies, we assessed several fitness parameters of Z. renardii when it fed on resistant S. frugiperda that had fed on Bt maize expressing Cry1F or on resistant T. ni that had fed on Bt cotton expressing Cry1Ac and Cry2Ab. Survival, nymphal duration, adult weight, adult longevity and female fecundity of Z. renardii were not different when they were fed resistant‐prey larvae (S. frugiperda or T. ni) reared on either a Bt crop or respective non‐Bt crops. ELISA tests demonstrated that the Cry proteins were present in the plant at the highest levels, at lower levels in the prey and at the lowest levels in the predator. While Z. renardii was exposed to Cry1F and Cry1Ac and Cry2Ab when it fed on hosts that consumed Bt‐transgenic plants, the proteins did not affect important fitness parameters in this common and important predator. 相似文献
108.
Kroemer JA Coates BS Nusawardani T Rider SD Fraser LM Hellmich RL 《Molecular genetics and genomics : MGG》2011,286(1):37-56
Males are homogametic (ZZ) and females are heterogametic (WZ) with respect to the sex chromosomes in many species of butterflies
and moths (insect order Lepidoptera). Genes on the Z chromosome influence traits involved in larval development, environmental
adaptation, and reproductive isolation. To facilitate the investigation of these traits across Lepidoptera, we developed 43
degenerate primer pairs to PCR amplify orthologs of 43 Bombyx mori Z chromosome-linked genes. Of the 34 orthologs that amplified by PCR in Ostrinia nubilalis, 6 co-segregated with the Z chromosome anchor markers kettin (ket) and lactate dehydrogenase (ldh), and produced a consensus genetic linkage map of ~89 cM in combination with 5 AFLP markers. The O. nubilalis and B. mori Z chromosomes are comparatively co-linear, although potential gene inversions alter terminal gene orders and a translocation
event disrupted synteny at one chromosome end. Compared to B. mori orthologs, O. nubilalis Z chromosome-linked genes showed conservation of tissue-specific and growth-stage-specific expression, although some genes
exhibited species-specific expression across developmental stages or tissues. The O. nubilalis Z chromosome linkage map provides new tools for isolating quantitative trait loci (QTL) involved in sex-linked traits that
drive speciation and it exposes genome rearrangements as a possible mechanism for differential gene regulation in Lepidoptera. 相似文献
109.
110.
Draube A Klein-González N Mattheus S Brillant C Hellmich M Engert A von Bergwelt-Baildon M 《PloS one》2011,6(4):e18801