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61.
The Karoo is a unique region in South Africa in terms of its ecological processes and endemic species. Large areas are needed to maintain viable populations of nomadic birds that follow erratic rainfall events and subsequent food and nesting resources, as well as ephemeral standing water. Whereas many species are adapted to arid conditions, our trait-based analysis found that an unusually large percentage (almost 45%) of 315 bird species in the semi-arid Karoo region rely on water to some degree. Indeed, some birds may have benefited from human activities to date, such as through the provision of water for livestock. However, this reliance on water makes birds vulnerable to changes in water quality stemming from various industrial developments. Given the large areas of the Karoo under consideration for concessions, the most noteworthy of these is hydraulic fracturing for shale gas, which results in a large quantity of waste water (‘produced water’) that contains a wide variety of chemicals, including petroleum byproducts. Given the negative impacts of secondary waste water on wildlife in other parts of the world where shale-gas exploration is being undertaken, careful attention must be given to preventing access to such produced water by an estimated 60 to 141 species of birds that make use of the water in the Karoo. 相似文献
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Fiona?T.?M. Chang F. Lyn Chan James D. R.?McGhie Maheshi Udugama Lynne Mayne Philippe Collas Jeffrey R. Mann Lee H. Wong 《Nucleic acids research》2015,43(5):2603-2614
Human ALT cancers show high mutation rates in ATRX and DAXX. Although it is well known that the absence of ATRX/DAXX disrupts H3.3 deposition at heterochromatin, its impact on H3.3 deposition and post-translational modification in the global genome remains unclear. Here, we explore the dynamics of phosphorylated H3.3 serine 31 (H3.3S31ph) in human ALT cancer cells. While H3.3S31ph is found only at pericentric satellite DNA repeats during mitosis in most somatic human cells, a high level of H3.3S31ph is detected on the entire chromosome in ALT cells, attributable to an elevated CHK1 activity in these cells. Drug inhibition of CHK1 activity during mitosis and expression of mutant H3.3S31A in these ALT cells result in a decrease in H3.3S31ph levels accompanied with increased levels of phosphorylated H2AX serine 139 on chromosome arms and at the telomeres. Furthermore, the inhibition of CHK1 activity in these cells also reduces cell viability. Our findings suggest a novel role of CHK1 as an H3.3S31 kinase, and that CHK1-mediated H3.3S31ph plays an important role in the maintenance of chromatin integrity and cell survival in ALT cancer cells. 相似文献
64.
Mitochondrial DNA (mtDNA) sequences that include (a) a part of the
cytochrome b gene, (b) two tRNA genes, and (c) a part of the noncoding
D-loop region of 31 Anguilla japonica (Japanese eel) and 1 A. marmorata
collected from Taiwan, Japan, and mainland China were determined to
evaluate the population structure of Japanese eel. Among 30 genotypes
identified from the 31 Japanese eel mtDNAs sequenced, there are 58 variable
sites, predominantly clustered at the D-loop region. The phylogenetic tree
constructed by the unweighted pair-group method with arithmetic mean shows
neither significant genealogical branches nor geographic clusters.
Furthermore, the sequence-statistics test reveals little, if any,
significant genetic differentiation. These results indicate that the 31
Japanese eels might come from a single population. Analysis of sequence
variation in mtDNA by using the relationship between the number of
segregating sites and the average number of nucleotide differences under
the neutral mutation hypothesis reveals that neutral mutation acts as a
major factor influencing the evolutionary divergence of the Japanese eel
mitochondrial genome sequenced, especially in the noncoding region.
相似文献
65.
A high-throughput fluorescence polarization assay has been developed for the detection of biotin and biotin-binding proteins in whole leaf extracts. Various groups are investigating the insecticidal properties of avidin and other biotin-binding proteins expressed in leaves of transgenic plants. The methods commonly used to quantify biotin and avidin in leaf extracts are enzyme-linked immunosorbent assay (ELISA) and Western blotting. Here we describe a homogeneous fluorescence polarization (FP) method that quantifies transgenic avidin in whole leaf extract by the simple addition of the fluorescent avidin ligand Alexa-Fluor 594 biocytin (AFB). The FP assay exploits the fact that AFB excites and emits in regions of the spectrum that are relatively free of background fluorescence in leaf extract. Transgenic leaf avidin can be quantified within 1-2 h by the FP method, in comparison with 1-2 days for ELISA and Western blotting. The FP method can also measure the amount of biotin in control leaves, not expressing avidin. Functional avidin levels of 1.54 μM (26.1 μg/g leaf tissue) were detected in tobacco leaves expressing vacuole-targeted avidin. Control leaves had biotin levels of around 0.74 μM (∼0.18 μg/g leaf tissue). Reagent costs are minimal: typically AFB is used at concentrations of 1-10 nM, avidin is used at 1-100 nM, and sample volumes are 20 μL in 384-well microplates. 相似文献
66.
An R2R3 MYB transcription factor associated with regulation of the anthocyanin biosynthetic pathway in Rosaceae 总被引:10,自引:0,他引:10
67.
A phylogenetic survey using the polymerase chain reaction (PCR) has
identified four major P element subfamilies in the saltans and willistoni
species groups of Drosophila. One subfamily, containing about half of the
sequences studied, consists of elements that are very similar to the
canonical (and active) P element from D. melanogaster. Within this
subfamily, nucleotide sequence differentiation among different copies from
the same species and among elements from different species is relatively
low. This observation suggests that the canonical elements are relatively
recent additions to the genome or, less likely, are evolving slowly
relative to the other subfamilies. Elements belonging to the three
noncanonical lineages are distinct from the canonical elements and from one
another. Furthermore, there is considerably more sequence variation, on the
average, within the noncanonical subfamilies compared to the canonical
elements. Horizontal transfer and the coexistence of multiple,
independently evolving element subfamilies in the same genome may explain
the distribution of P elements in the saltans and willistoni species
groups. Such explanations are not mutually exclusive, and each may be
involved to varying degrees in the maintenance of P elements in natural
populations of Drosophila.
相似文献
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DN Akongyuure S Amisah TK Agyemang RE Edziyie 《African Journal of Aquatic Science》2017,42(2):143-154
Fishery characteristics and livelihood status of fishers at Tono Reservoir, Ghana, were investigated between January 2015 and June 2016. Data on fisher demography, fishing gears, fishing methods, perceptions of the state of fish stocks, management practices, income and consumption of fishers were obtained through structured interviews. Censuses of fishers and fishing gears were conducted through direct observation and counts. The population of fishers was 950 and the majority (74%) of the sampled respondents fell within the ages of 24–41 years. Gillnet, cast net, trap and hook and line were the four main gears utilised. Illegal methods of fishing observed included the use of mosquito nets (nets with mesh <1.0 cm) and the use of brewer’s waste (pito mash) as bait. Brycinus nurse, Synodontis spp., Parailia spiniserrata and Chrysichthys spp. were perceived to have disappeared from the reservoir. The fishers were unaware of the existence of any fisheries regulations, hence there was no adherence to management practices. Their daily income was derived mainly from fishing. The incidence of poverty among fishers was low (8%). The Tono Reservoir has a great potential for supporting livelihood if it is properly managed. 相似文献