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181.
In both cell cultures and seedling roots from dill (Anethum graveolens L.) UV irradiation selectively induced a quercetin arabinoside and two other phenylpropanoid compounds with caffeic acid as the aglycone. Only wavelengths below 360 nm were effective in this induction. Maximal effectiveness was observed below 320 nm.Supported by the Deutsche Forschungsgemeinschaft (SFB 46).  相似文献   
182.
The leu-enkephalin containing opioid peptides α-neo-endorphin and β-neo-endorphin [i.e., α-neo-endorphin(1–9)] were measured in rat brain region extracts with two highly specific radioimmunoassays. The molar ratio of α-neo-endorphin to β-neo-endorphin was extremely variable among brain regions. In hypothalamus and posterior pituitary β-neo-endorphin levels were almost as high as α-neo-endorphin levels. In contrast, in the striatum α-neo-endorphin was 30-fold more concentrated than β-neo-endorphin. In all other brain regions α-neo-endorphin was present in 3 to 20-fold higher concentrations than β-neo-endorphin. The β-neo-endorphin immunoreactive material was found to comigrate with authentic β-neo-endorphin on reverse phase HPLC. These findings suggest that in certain brain regions but not in others processing mechanisms exist which can generate β-neo-endorphin through processing of α-neo-endorphin or its precursors.  相似文献   
183.
An extract from 50 rat posterior intermediate pituitaries was fractionated by gel filtration followed by cation exchange chromatography. α-N-Acetylated derivatives of β-endorphin-like molecules were detected with a specific radioimmunoassay for α-N-acetylβ-endorphins. Six peaks of α-N-acetylβ-endorphin-like immunoreactivity were observed in the cation exchange chromatography fractions. One of these peaks was purified to homogeneity using reverse phase high performance liquid chromatography (RP-HPLC). The isolated peptide was characterized by tryptic digestion followed by RP-HPLC and by amino acid analysis. The results showed that the isolated peptide was α-N-acetylβ-endorphin(1–26) with an oxidized methionine residue at position 5. Two previously unrecognized α-N-acetylβ-endorphin derivatives were also observed during the isolation procedure.  相似文献   
184.
185.

Background  

Young women diagnosed with breast cancer are known to have a higher mortality rate from the disease than older patients. Specific risk factors leading to this poorer outcome have not been identified. In the present study, we hypothesized that iron deficiency, a common ailment in young women, contributes to the poor outcome by promoting the hypoxia inducible factor-1α (HIF-1α and vascular endothelial growth factor (VEGF) formation. This hypothesis was tested in an in vitro cell culture model system.  相似文献   
186.
The development and use of, as well as scientific discussions on, eco-balances and in particular life cycle assessment has largely occurred without involving experts on environmental law. However, in the light of recent proposals to ‘legalize’ eco-balances, i.e. formally introducing them into environmental law, the legal implications of eco-balancing must be addressed in the future. The formal introduction, especially of LCA, cannot be decided independent of the general economic and environmental policy implications of material flow management, and it raises major questions of policy and constitutional law. An important question of principle is whether eco-balances should be prescribed or only a legal framework set forth for voluntary use. In view of the unfinished methodological development of LCA, any formal introduction raises the constitutional problem of conformity with the requirements of legal certainty. References to the ‘principles of good eco-balancing’ are problematic, and an introduction on an experimental basis would have to be confined to cases where the legal consequences of grossly divergent interpretations of this term are tolerable to affected firms. Where eco-balances are prescribed as a method of preparing governmental or administrative decisions, one must determine whether and to what extent they are binding on the decision-maker, and develop proper mechanisms of participation, transparency and critical review.  相似文献   
187.
The poliovirus vaccine field is moving towards novel vaccination strategies. Withdrawal of the Oral Poliovirus Vaccine and implementation of the conventional Inactivated Poliovirus Vaccine (cIPV) is imminent. Moreover, replacement of the virulent poliovirus strains currently used for cIPV with attenuated strains is preferred. We generated Cold-Adapted Viral Attenuation (CAVA) poliovirus strains by serial passage at low temperature and subsequent genetic engineering, which contain the capsid sequences of cIPV strains combined with a set of mutations identified during cold-adaptation. These viruses displayed a highly temperature sensitive phenotype with no signs of productive infection at 37°C as visualized by electron microscopy. Furthermore, decreases in infectious titers, viral RNA, and protein levels were measured during infection at 37°C, suggesting a block in the viral replication cycle at RNA replication, protein translation, or earlier. However, at 30°C, they could be propagated to high titers (9.4–9.9 Log10TCID50/ml) on the PER.C6 cell culture platform. We identified 14 mutations in the IRES and non-structural regions, which in combination induced the temperature sensitive phenotype, also when transferred to the genomes of other wild-type and attenuated polioviruses. The temperature sensitivity translated to complete absence of neurovirulence in CD155 transgenic mice. Attenuation was also confirmed after extended in vitro passage at small scale using conditions (MOI, cell density, temperature) anticipated for vaccine production. The inability of CAVA strains to replicate at 37°C makes reversion to a neurovirulent phenotype in vivo highly unlikely, therefore, these strains can be considered safe for the manufacture of IPV. The CAVA strains were immunogenic in the Wistar rat potency model for cIPV, inducing high neutralizing antibody titers in a dose-dependent manner in response to D-antigen doses used for cIPV. In combination with the highly productive PER.C6 cell culture platform, the stably attenuated CAVA strains may serve as an attractive low-cost and (bio)safe option for the production of a novel next generation IPV.  相似文献   
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