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81.
Sex-determining region Y-box 2 (SOX2)-positive cells are stem/progenitor cells in the adenohypophysis, comprising the anterior and intermediate lobes (AL and IL, respectively). The cells are located in the marginal cell layer (MCL) facing Rathke’s cleft (primary niche) and the parenchyma of the AL (secondary niche). We previously demonstrated in vitro that the tetraspanin superfamily CD9 and SOX2 double-positive (CD9/SOX2-positive) cells in the IL-side MCL migrate to the AL side and differentiate into hormone-producing and endothelial cells in the AL parenchyma. Here, we performed in vivo studies to evaluate the role of IL-side CD9/SOX2-positive cells in pregnancy, lactation, and treatment with diethylstilbestrol (DES; an estrogen analog) when an increased population of prolactin (PRL) cells was observed in the AL of the rat pituitary. The proportions of CD9/SOX2-, CD9/Ki67-, and PRL/TUNEL-positive cells decreased in the primary and secondary niches during pregnancy and DES treatment. In contrast, the number of CD9/PRL-positive cells increased in the AL-side MCL and AL parenchyma during pregnancy and during DES treatment. The proportion of PRL/Ki67-positive cells increased in the AL-side MCL and AL parenchyma in response to DES treatment. Next, we isolated CD9-positive cells from the IL-side MCL using an anti-CD9 antibody. During cell culture, the cells formed free-floating three-dimensional clusters (pituispheres). Furthermore, CD9-positive cells in the pituisphere differentiated into PRL cells, and their differentiation potential was promoted by DES. These findings suggest that CD9/SOX2-positive cells in the IL-side MCL may act as adult stem cells in the AL parenchyma that supply PRL cells under the influence of estrogen.  相似文献   
82.
The positive and negative effects of the residual stand edge at a strip-clearcut site were examined on the initial growth of hinoki (Chamaecyparis obtusa) planted in areas with diverse topography. On the south edge, the gap light index was lower than on the north edge and strip center; however, the vapor pressure deficit was also lower than on the north edge and strip center, which resulted in lower physiological stress of hinoki on the south edge. Tree size on the south edge did not exceed that on the north edge and strip center. These results indicated that low light conditions due to residual trees negatively affected growth on the south edge even under the positive effect of microclimate alleviation. In valley, tree size in the second year after planting was smaller than on ridge and slope; however, tree growth during the following 2 years was higher in valley. Surface soil in valley was thinner with rockier substrates than on ridge and slope; that is, soil sedimentation type and substrates influenced the initial growth of hinoki with undeveloped roots, and after that, topography started to influence growth, probably because hinoki roots penetrated into deeper soil, which is influenced by the water gathering capacity of the valley. The initial growth of hinoki at the strip-clearcut site was predominantly affected by light rather than microclimate alleviation. This alleviation is expected to disappear when hinoki trees planted in the strip center grow enough to give additional shade to slow-growing edge hinoki.  相似文献   
83.
We examined antimicrobial susceptibility and efflux systems in laboratory-derived mutants of Salmonella enterica serovar Choleraesuis selected by culture on fluoroquinolone-containing plates. The mutants exhibited decreased susceptibilities to quinolones and several other antimicrobials. Mutations in the gyrA gene were not always found in the mutants. Accumulation assays revealed that intracellular enrofloxacin concentrations were significantly lower in the mutants compared with parent isolates. Increased expression of acrB mRNA can explain the decreased susceptibilities to several antimicrobials but not in the case of carbonyl cyanide m-chlorophenylhydrazone (CCCP). Decreased susceptibility to CCCP may result from the increased expression of emrA mRNA. These results suggest that the enhancement of multiple efflux pumps is responsible for decreased susceptibilities to several antimicrobials in the laboratory-derived mutants.  相似文献   
84.
85.
Seed size is an important trait in determinant of rice seed quality and yield. In this study, we report a novel semi-dominant mutant Small and round seed 5 (Srs5) that encodes alpha-tubulin protein. Lemma cell length was reduced in Srs5 compared with that of the wild-type. Mutants defective in the G-protein alpha subunit (d1-1) and brassinosteroid receptor, BRI1 (d61-2) also exhibited short seed phenotypes, the former due to impaired cell numbers and the latter due to impaired cell length. Seeds of the double mutant of Srs5 and d61-2 were smaller than those of Srs5 or d61-2. Furthermore, SRS5 and BRI1 genes were highly expressed in Srs5 and d61-2 mutants. These data indicate that SRS5 independently regulates cell elongation of the brassinosteroid signal transduction pathway  相似文献   
86.
87.
Three electrophoretic variations (AA, BB and AB) of ovalbumin controlled by codominant alleles OvA and OvB have been observed in various chicken populations. We compared nucleotide sequences of the open reading frame between two alleles of ovalbumin gene. The difference between the two alleles was found as a non‐synonymous substitution of asparagine to aspartic acid as a result of AAT to GAT point mutation at position 8032–8034 in exon 8. We developed polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) protocol in combination with Mbo I restriction endnuclease mapping for the detection of this substitution. By the PCR‐RFLP the allelic frequency of the OvB was estimated to be within the range of 0.000–0.150 in 11 Asian indigenous chicken populations and 0.000 in four improved breeds used in the present study. Gene frequency, estimated by PCR‐RFLP in the present study, paralleled that obtained by protein polymorphisms of egg white. Thus, this study provides, for the first time, information of the occurrence of ovalbumin allele OvA and OvB in Asian indigenous chicken populations.  相似文献   
88.
Serological methods were utilized to detect Anaplasma and Ehrlichia infection in domestic animals in Xinjiang Uygur Autonomous Region, China. By using an indirect immunofluorescence assay (IFA), antibodies that reacted with Anaplasmaphagocytophilum and Ehrlichiachaffeensis were detected mainly in ruminants kept on pastureland in Altai, Ili and Kashgar area. Antibody titers up to 1:320 were recorded. These results indicate that ruminants kept in these areas may be infected with some species of Anaplasma and Ehrlichia.  相似文献   
89.
Effects of seed and root exudates obtained from common bean on the proliferation of Rhizobium sp. (Phaseolus) were examined in a combination of three plant cultivars with three Rhizobium strains. In the first experiment, seed or root exudate was mixed with an Andosol soil extract, and bacterial proliferation in the mixture was traced. Seed exudate was prepared from hydroponic solution used in seed imbibition for 24 h, and a series of root exudates was prepared from a hydroponic solution collected every 24 h from the initiation of rooting up to 96 h after rooting. Regardless of the common bean cultivars and Rhizobium strains used, Rhizobium population markedly increased of the 24 h of culture in the mixture containing seed exudates, whereas a negligible increase was detected in the mixture with root exudates. The mixture containing root exudates collected within a period of 72–96 h after initial rooting (96–120 h after seed imbibition) exerted an inhibitory effect on Rhizobium proliferation. The seed exudates contained large amounts of sugars, amino acids, nitrogen, phosphorus, potassium, and magnesium compared to any root exudates. In the second experiment, Rhizobium was inoculated directly to common bean seeds sowed in a vermiculite bed which was sterilized and moistened with a plant nutrient solution. Compared with the control (without seed), a remarkable increase in the number of bacterial cells was observed in all the combinations of plant cultivars and Rhizobium strains 24 h after sowing. These results reveal that seed exudates of common bean have a substantial potential to promote Rhizobium proliferation, and that root exudates in a particular period of culture contain some inhibitory factors.  相似文献   
90.
International trade in vulnerable marine species is regulated once they are listed in CITES Appendices (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). Parties to the Convention submit proposal(s) 150 days prior to the CITES Conference for voting on the inclusion of new species in Appendices I and II, making a case for why CITES listing criteria are met in each case. Before the vote, Parties receive advice from (a) the Food and Agriculture Organization of the United Nations, (b) the International Union for Conservation of Nature—TRAFFIC and (c) the CITES Secretariat, among others. This paper offers an expert review of listing processes, which are the subject of much debate in fishery and environment‐protection communities, looking at two specific cases: silky shark (Carcharhinus falciformis, Carcharhinidae) and bigeye thresher shark (Alopias superciliosus, Alopiidae). The reviewers determine that the evidence made available to voting Parties is substantial, but suffers from non‐standard presentation across assessments. The best available data are not always presented or described transparently in relation to CITES criteria. An extension of the assessment period, as well as the opportunity to refute evidence, has been suggested as ways to support more informed and effective decision‐making by CITES Parties, whose composition of delegations varies greatly in their experience of marine species management and trade. Experts welcomed a greater coherence of advice between fishery and non‐fishery sources in the long term, and proposed a range of suggested improvements for the delivery of information and advice to CITES Parties.  相似文献   
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