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Cloned DNAs encoding four different proteins have been isolated from recombinant cDNA libraries constructed with Glycine max seed mRNAs. Two cloned DNAs code for the alpha and alpha'-subunits of the 7S seed storage protein (conglycinin). The other cloned cDNAs code for proteins which are synthesized in vitro as 68,000 d., 60,000 d. or 53,000 d. polypeptides. Hybrid selection experiments indicate that, under low stringency hybridization conditions, all four cDNAs hybridize with mRNAs for the alpha and alpha'-subunits and the 68,000 d., 60,000 d. and 53,000 d. in vitro translation products. Within three of the mRNA, there is a conserved sequence of 155 nucleotides which is responsible for this hybridization. The conserved nucleotides in the alpha and alpha'-subunit cDNAs and the 68,000 d. polypeptide cDNAs span both coding and noncoding sequences. The differences in the coding nucleotides outside the conserved region are extensive. This suggests that selective pressure to maintain the 155 conserved nucleotides has been influenced by the structure of the seed mRNA. RNA blot hybridizations demonstrate that mRNA encoding the other major subunit (beta) of the 7S seed storage protein also shares sequence homology with the conserved 155 nucleotide sequence of the alpha and alpha'-subunit mRNAs, but not with other coding sequences.  相似文献   
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Background  

To date, 35 human diseases, some of which also exhibit anticipation, have been associated with unstable repeats. Anticipation has been reported in a number of diseases in which repeat expansion may have a role in etiology. Despite the growing importance of unstable repeats in disease, currently no resource exists for the prioritization of repeats. Here we present Satellog, a database that catalogs all pure 1–16 repeat unit satellite repeats in the human genome along with supplementary data. Satellog analyzes each pure repeat in UniGene clusters for evidence of repeat polymorphism.  相似文献   
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Analysis of the expression of genes encoding the β-conglycinin seed storage proteins in soybean has been used to extend our understanding of developmental gene expression in plants. The α, α′, and β subunits of β-conglycinin are encoded by a multigene family which is organ-specific in its expression. In this study we report the differentially programmed accumulation of the α, α′, and β subunits of β-conglycinin. Multiple isomeric forms of each subunit are present in the dry seed, but the timing of their accumulation is unique for each subunit. The previously reported variation in amount of α′ and α subunits in axis and cotyledons is also reflected in the amount of subunit specific mRNA which is present in each tissue. The β subunit, previously undetected in soybean axes, is found to be synthesized but rapidly degraded. These differences in β-conglycinin protein accumulation may be reflected by the morphological differences observed in protein bodies between these two tissues.  相似文献   
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X-ray study of chicken cytosolic aspartate aminotransferase revealed conformational changes in the protein of two kinds: (1) a shift of the small domain adjacent to substrate-binding area due to interaction of the protein with two carboxyl groups of substrate and (2) a change in inclination of the coenzyme plane due to replacement of C = N bond of the coenzyme with Lys-258 by C = N bond with a substrate. An asymmetry in subunit behaviour is observed in both cases: the domain is shifted in one subunit and the coenzyme is rotated in other. Substrate-binding properties of each subunit are strictly dependent on the protein conformation in substrate-binding area.  相似文献   
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Background  

We present a biological data warehouse called Atlas that locally stores and integrates biological sequences, molecular interactions, homology information, functional annotations of genes, and biological ontologies. The goal of the system is to provide data, as well as a software infrastructure for bioinformatics research and development.  相似文献   
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Urban environments impose novel selection pressures with varying impacts across species and life history stages. The post‐fledging stage for migratory passerines, defined as the period of time from when hatch‐year birds fledge until their first migration, is a poorly understood component of annual productivity that potentially limits population growth. We studied two migratory passerines with positive and negative population responses to urbanization, respectively: gray catbird Dumetella carolinensis and wood thrush Hylocichla mustelina. Our goals were to estimate post‐fledging survival rates for urban bird populations and determine which features of the urban landscape impact mortality risk during the post‐fledging stage. From 2012–2014, we tracked 127 fledglings (60 gray catbirds and 67 wood thrushes). Over 55 d after fledging, cumulative survival of gray catbirds (0.32 [95% CI: 0.22–0.47]) was approximately half that of wood thrushes (0.63 [95% CI: 0.52–0.75]). Thus, survival rates during the post‐fledging stage, taken in isolation, do not explain differential trajectories of gray catbird and wood thrush populations in urban environments. Most mortality (86%) for both species was due to predation. However, after reaching independence from parental care, 6 birds (9.4% of mortalities) died of anthropogenic causes (e.g. building, car strikes). Crossing roads significantly increased mortality risk, but increasing daily movement distance decreased mortality risk. Our results raise the question of whether anthropogenic sources of mortality are compensatory or additive to natural mortality; we emphasize the need to monitor fledgling survival beyond the parental‐dependence stage in order to fully understand the impacts of anthropogenic hazards on juvenile birds.  相似文献   
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Peri-urban water bodies are at risk from excessive pollution as they are direct sinks for urban effluents. The occurrence of oestrogenic and androgenic endocrine disrupting chemicals (EDCs) in effluents and water bodies around the city of Bulawayo, Zimbabwe, and their effects on wild fish was investigated in 2013. Effluent and water were sampled from sewage treatment plants, an urban stream, and effluent-polluted dams, and were compared with a ‘pristine’ dam upstream of Bulawayo. Organic pollutants were extracted by solid-phase extraction and tested for EDCs using a yeast oestrogen/androgen screen. Oestrogenic and androgenic potencies were expressed as 17β-oestradiol equivalent (EEq) or dihydrotestosterone equivalent (TEq). Tilapia and catfish from the dams were analysed for gonado-somatic indices and testis histopathology. Effluents from STPs, which directly flow into Umguza Dam, had EEq of 33 ng l?1 and 55 ng l?1, respectively. Umguza Dam, Khami Dam and Matsheumhlope Stream had EEqs of 237 ng l–1, 9 ng l?1 and 2 ng l?1, respectively. Androgenic activity was detected in only one STP (TEq = 93 ng l?1). Tilapia sampled from effluent-polluted dams had high incidences of testis-ova, but catfish had no signs of reproductive dysfunction. These findings underscore the need for greater attention to EDCs in developing countries where there is scant literature regarding their occurrence and impacts.  相似文献   
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