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61.
Harvesting of Non‐Timber Forest Products (NTFPs) can threaten target species, especially those with limited distribution and density. Exploited species also face threats from habitat fragmentation, fire, and invasive species. We assessed the impact of human disturbances and invasive species on the population of a key multipurpose NTFP species, Mimusops andongensis, in Lama Forest reserve (Benin). The densities of adult trees and regenerative stems decreased with increasing degradation. Mimusops andongensis contributed less to total tree density with increasing human disturbance. There were significantly fewer M. andongensis recruits with increasing cover of invasive Chromolaena odorata. Smaller diameter individuals predominated in non‐degraded and moderately degraded sites while in degraded sites, the structure showed a negative exponential trend with the density of small diameter individuals being less than two trees/ha. Larger individuals were also rare in degraded sites. The low density of both mature trees and seedlings in degraded sites may undermine the long‐term viability of M. andongensis, despite existing protection against NTFP harvesting and other anthropogenic pressures. Management should emphasize facilitating recruitment subsidies and limiting the presence of C. odorata.  相似文献   
62.
Biomarkers of some pulmonary diseases in exhaled breath   总被引:16,自引:0,他引:16  
Analysis of various biomarkers in exhaled breath allows completely non-invasive monitoring of inflammation and oxidative stress in the respiratory tract in inflammatory lung diseases, including asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF), bronchiectasis and interstitial lung diseases. The technique is simple to perform, may be repeated frequently, and can be applied to children, including neonates, and patients with severe disease in whom more invasive procedures are not possible. Several volatile chemicals can be measured in the breath (nitric oxide, carbon monoxide, ammonia), and many non-volatile molecules (mediators, oxidation and nitration products, proteins) may be measured in exhaled breath condensate. Exhaled breath analysis may be used to quantify inflammation and oxidative stress in the respiratory tract, in differential diagnosis of airway disease and in the monitoring of therapy. Most progress has been made with exhaled nitric oxide (NO), which is increased in atopic asthma, is correlated with other inflammatory indices and is reduced by treatment with corticosteroids and antileukotrienes, but not (β2-agonists. In contrast, exhaled NO is normal in COPD, reduced in CF and diagnostically low in primary ciliary dyskinesia. Exhaled carbon monoxide (CO) is increased in asthma, COPD and CF. Increased concentrations of 8-isoprostane, hydrogen peroxide, nitrite and 3-nitrotyrosine are found in exhaled breath condensate in inflammatory lung diseases. Furthermore, increased levels of lipid mediators are found in these diseases, with a differential pattern depending on the nature of the disease process. In the future it is likely that smaller and more sensitive analysers will extend the discriminatory value of exhaled breath analysis and that these techniques may be available to diagnose and monitor respiratory diseases in the general practice and home setting.  相似文献   
63.
Ornithine decarboxylase (ODC) is an enzyme that initiates polyamine synthesis in human. Polyamines play key roles in cell–cell adhesion, cell motility and cell cycle regulation. Higher synthesis of polyamines also occurs in rapidly proliferating cancer cells are mediated by ODC. As per earlier studies, di-flouro-methyl-orninthine (DFMO) is a proven efficient inhibitor ODC targeting the catalytic activity, however, its usage is limited due to side effects. Targeting ODC is considered as a potential therapeutic modality in the treatment of cancer. In this study, it is attempted to use DFMO scaffold to build a ligand-based pharmocophore query using MOE to screen similar active compounds from Universal Natural Products Database with better ADMET properties. The identified compounds were virtually screened against the active cavity of ODC using Glide. Further, potential natural hits targeting ODC were shortlisted based on Molecular Mechanics/Generalized-Born/Surface Area (MM-GBSA) score. Finally, molecular dynamics simulations were performed for the natural molecule hit and DFMO in complex with ODC using Desmond. Among the hits shortlisted, 2-amino-5, 9, 13, 17-tetramethyloctadeca-8, 16-diene-1, 3, 14-triol (UNPD208110) was found to be highly potential, as it showed a higher binding affinity in terms of interactions with key active cavity residues, and also showed better ADMET property, HUMO–LUMO gap energy and more stable complex formation with ODC compared to DFMO. Hence, the proposed molecule (UNPD208110) shall be favourably considered as a potential natural inhibitor targeting ODC-mediated disease conditions.  相似文献   
64.
One of the mosquito-borne zoonotic diseases is the Rift Valley fever virus (RVFV). Currently, there is no completely licensed vaccine that can be used to vaccinate animals or humans outside endemic areas. The aim of this work was to use the RVFV glycoprotein (Gn) and the subunit B of cholera toxin (CTB) at gene level and build up fused recombinant vaccine. The gene of CTB was joined to the gene Gn to work as an adjuvant in the resulting fusion protein. The designed merged genes (CTB-Gn) was tested for restriction sites, open reading frames, expected fusion protein tertiary structure and antigenicity using computer software. The insert sequence was submitted to the BioProject (GenBank). The insert was subcloned into the pQE-31 expression plasmid. The target recombinant protein (rCTB-Gn) was expressed in M15 bacteria, purified and identified by protein gel electrophoresis. The insert got the accession No: PRJNA386723. Analysis of the designed rCTB-Gn protein revealed that it had the right 3D structure, immunogenic and at the correct molecular weight. The presence of the CTB in the proposed vaccine will augment its immunogenicity. Doses and protection levels of the vaccine need to be manipulated.  相似文献   
65.
Aims: A new assay, much more rapid and efficient than the existing standardized tests, is introduced for the evaluation of bactericidal activity of chemical disinfectants and antiseptics under simulated practical conditions of use. Methods and Results: The bactericidal activity of biocides was quantified using a novel semi‐automated assay based on the European Norm (EN) standard suspension tests but determining bacterial cell viability by intracellular adenosine tri‐phosphate (ATP) content quantification instead of traditional culture‐based microbiological techniques. The new test was validated by comparison to the standard suspension tests EN 1276 and EN 13727. During the validation, the linearity of the ATP detection system, limit of detection, specificity, sensitivity, relative accuracy and precision (repeatability and reproducibility) were determined. Conclusions: The validation study showed that the new assay evaluates the activity of biocides as well as the EN standard suspension tests, but it allows a large number of test conditions to be efficiently analysed. Significance and Impact of the Study: The new test can therefore be applied to accurately establish the lowest active concentration (MBCs) of disinfectants or antiseptics under simulated practical conditions of use and to compare the susceptibility of a large number of strains and conditions via inactivation curves. This is not possible in any reasonably practicable way with the EN standards considering the time and cost required for each determination.  相似文献   
66.
Annona muricata Linnaeus, popularly known as “graviola” and also called soursop, is a species typical of countries with a tropical climate, and it is used in folk medicine as an anticancer, analgesic and antispasmodic agent. The aim of the present study was to validate the gastroprotective activity of the hydroalcoholic extract of the leaves of A. muricata (HEAM) and to investigate the underlying mechanisms of action for this effect. Gastric lesions were induced in mice by absolute ethanol, acidified ethanol or indomethacin. Before, the animals were pretreated with saline, omeprazole or HEAM orally at doses of 50–400 mg/kg. To determine the mechanism of action of the extract, we investigated, using specific inhibitors, the involvement of nitric oxide (NO), prostaglandins (PGEs), ATP-dependent K+ channels and α2-noradrenergic receptors. HEAM showed significant antiulcer activity against lesions induced by absolute ethanol, acidified ethanol or indomethacin, which was mediated by endogenous gastric prostaglandins.  相似文献   
67.
68.
In this short communication, lignin produced by steam processing of agricultural (hemp) and forestry (softwood) was depolymerised via a base catalysis to produce a combination of monomers, dimers, trimers and residual char. The lignin broth produced directly after the base-catalysed steam treatment was treated under pressure (from 1300 to 1900 psi) at temperatures varying from 300 to 330 °C in a custom-made batch reactor. The lignin concentration in the aqueous base solution was 10 wt% whilst the NaOH concentration was 5 wt%. Identification of 26 compounds has been done: 17 compounds were common to the two feedstocks while the remaining 9 were specific to each feedstock used.  相似文献   
69.
Stacpoole PW 《Mitochondrion》2011,11(5):679-685
Although mitochondrial disease research in general is robust, adequate treatment of these life-threatening conditions has lagged, partly because of a persistence of clinical anecdotes as substitutes for scientifically and ethically rigorous clinical trials. Here I summarize the key lessons learned from some of the “first generation” of randomized controlled trials for genetic mitochondrial diseases and suggest how future trials may benefit from both past experience and exciting new resources available for patient-oriented research and training in this field.  相似文献   
70.
Nitrogen trials were carried out on hemp crops grown in Ireland over a 3 year period to identify nitrogen fertilization strategies which optimize the greenhouse gas (GHG) and energy balances of hemp crops grown for biomass. Nitrogen rates up to 150 kg N ha?1 were used in the study. Yield increased with nitrogen rate up to 120 kg N ha?1 for early (Ferimon), mid (Felina 32) and late maturing (Futura 75) varieties. Variety had a significant effect on yield with yields increasing with maturation date. In 2 years of the study, certain application rates of nitrogen were applied either at sowing, at emergence, after emergence or split between these dates to determine if nitrogen rates could be reduced by delaying or splitting the applications. The application of nitrogen at times later than sowing or in splits during the early part of the growing season had no significant effect on biomass yield compared with the practice of applying nitrogen at the time of sowing. Late applications of nitrogen reduced leaf chlorophyll content and height early in the growing season. Later in the growing season, there was no difference in height between treatments although the highest concentrations of chlorophyll were found in the leaves of the late application treatment. Nitrogen rate and the timing of nitrogen application had no effect on plant density. Biomass yield, net energy and net GHG mitigation increased up to an application rate of 120 kg N ha?1, this result was independent of soil type or soil nitrogen level. Net GHG and energy balance of hemp crops grown for biomass are optimized if late maturing varieties are used for biomass production and a nitrogen rate of 120 kg ha?1 is applied at sowing.  相似文献   
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