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31.
The degradation of dissolved and colloidal substances from thermomechanical pulp (TMP) by bacteria isolated from a paper mill was studied in a laboratory slide culture system.Burkholderia cepacia strains hydrolysed triglycerides to free fatty acids, and the liberated unsaturated fatty acids were then degraded to some extent. Saturated fatty acids were not notably degraded. However, the branched anteiso-heptadecanoic fatty acid was degraded almost like the unsaturated fatty acids. About 30% of the steryl esters were degraded during 11 days, increasing the concentrations of free sterols. Approximately 25% of the dehydroabietic, and 45% of the abietic and isopimaric resin acids were degraded during 11 days. The degree of unsaturation seemed to be of greater importance for the degradation of fatty acids than the molar mass. No degradation of dissolved hemicelluloses could be observed with any of the nine bacterial strains studied. Burkholderia cepacia strains and one Bacillus coagulans strain degraded monomeric fructose and glucose in winter TMP water, but in summer TMP water, with much lower sugar concentrations, also otherBacillus strains degraded monomeric sugars.  相似文献   
32.
Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic factors (adhesin and toxin genes) and antibiotic susceptibility of isolates were carried out using gene amplification and disc diffusion assays, respectively. A high prevalence of MRSA was observed in the tested isolates (13.1%). The isolates were also highly resistant to antibiotics, i.e. 36.4% were resistant to streptomycin, 33.6% to oxytetracycline, 29.9% to gentamicin and 26.2% each to chloramphenicol, pristinomycin and ciprofloxacin. A significant variation in the expression of pathogenic factors (Ig, coa and clf) was observed in these isolates. The overall distribution of adhesin genes ebp, fib, bbp, fnbB, cap5, cap8, map and cna in the isolates was found to be 69.1, 67.2, 6.5, 20.5, 60.7, 26.1, 81.3 and 8.4%, respectively. The presence of fib, fnbB, bbp and map genes was considerably greater in MRSA than in methicillin-susceptible S. aureus (MSSA) isolates. The proportions of toxin genes, namely, hlb, seb, sec, sed, seg and sei, in the isolates were found to be 94.3, 0.9, 8.4, 0.9, 10.2 and 49.5%, respectively. The proportions of agr genes I, II, III and IV were found to be 39.2, 27.1, 21.5 and 12.1%, respectively. A few isolates showed similar antibiotic-resistance patterns, which could be due to identical strains or the dissemination of the same strains among animals. These findings can be utilized in mastitis treatment programmes and antimicrobials strategies in organized herds.  相似文献   
33.
Wood-derived naturally acetylated galactoglucomannans (AcGGM) can be recovered even in ton-scale at mechanical pulp mills using spruce as raw material. These cell wall polysaccharides have a great potential as hydrocolloids and bioactive polymers in food and pharmaceutical applications, or as starting material for production of functional polymers. The immunostimulatory activity of both AcGGM and its deacetylated form (GGM) was now in vitro tested. The biological response of both AcGGM and GGM in the lymphocyte transformation test was dose-dependent. The direct mitogenic as well as comitogenic activities of the AcGGM were comparable to those of the immunogenic corn cob xylan used as control, and GGM showed significantly higher biological responses also at lower doses. In contrast to GGM, AcGGM possessed also DPPH radical-scavenging activity. The results suggested that the spruce AcGGM and GGM are potentially important as additives with immuno-potentiating and antioxidant properties in food products and pharmaceutical formulations.  相似文献   
34.

Background  

The PII protein family comprises homotrimeric proteins which act as transducers of the cellular nitrogen and carbon status in prokaryotes and plants. In Herbaspirillum seropedicae, two PII-like proteins (GlnB and GlnK), encoded by the genes glnB and glnK, were identified. The glnB gene is monocistronic and its expression is constitutive, while glnK is located in the nlmAglnKamtB operon and is expressed under nitrogen-limiting conditions.  相似文献   
35.
36.

Background  

Cancer of the oral tongue is the second most common cancer among males in various parts of India. Despite advances in diagnosis and treatment the failure rates in cancer of the oral tongue are high and survival poor. Majority of these failures occur in untreated neck.  相似文献   
37.

Aims

The aim of this study was to examine the antimicrobial properties of novel aqueous natural rapeseed oil/saline emulsions containing different soluble components of spruce resin.

Methods and Results

The composition of aqueous resin emulsions was analysed by GC‐MS and their antimicrobial properties were studied with challenge tests and with turbidometric assays. The emulsions were strongly antimicrobial against common Gram‐positive and Gram‐negative bacteria (including MRSA) as well as common yeasts. Furthermore, they inhibited the biofilm formation and eradicated the microbial biofilms on tested microbes. Characteristic for the emulsions was the presence of oxidized resin acids. Other main components present in emulsions, such as lignans and coumaric acids, were not antimicrobial, when tested separately.

Conclusions

The results indicated that the oxidized resin acids were the antimicrobial components in the emulsions. Also, there appears to be a stoichiometric relationship between the number of resin acid molecules and the number microbe cells in the antimicrobial action.

Significance and Impact of the Study

The fact that these solutions do not contain abietic acid, which is the main allergenic compound in resins, suggests that these solutions would be suitable, well‐tolerated antimicrobials for various medical applications. The aqueous formulation will also allow the expansion of the use of these emulsions in from medical applications to the food preservatives and disinfectants.  相似文献   
38.
Prostate cancer is the most common cancer of men in the Western world, and novel approaches for prostate cancer risk reduction are needed. Plant-derived phenolic compounds attenuate prostate cancer growth in preclinical models by several mechanisms, which is in line with epidemiological findings suggesting that consumption of plant-based diets is associated with low risk of prostate cancer. The objective of this study was to assess the effects of a novel lignan-stilbenoid mixture in PC-3M-luc2 human prostate cancer cells in vitro and in orthotopic xenografts. Lignan and stilbenoid –rich extract was obtained from Scots pine (Pinus sylvestris) knots. Pine knot extract as well as stilbenoids (methyl pinosylvin and pinosylvin), and lignans (matairesinol and nortrachelogenin) present in pine knot extract showed antiproliferative and proapoptotic efficacy at ≥40 μM concentration in vitro. Furthermore, pine knot extract derived stilbenoids enhanced tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induced apoptosis already at ≥10 μM concentrations. In orthotopic PC-3M-luc2 xenograft bearing immunocompromized mice, three-week peroral exposure to pine knot extract (52 mg of lignans and stilbenoids per kg of body weight) was well tolerated and showed anti-tumorigenic efficacy, demonstrated by multivariate analysis combining essential markers of tumor growth (i.e. tumor volume, vascularization, and cell proliferation). Methyl pinosylvin, pinosylvin, matairesinol, nortrachelogenin, as well as resveratrol, a metabolite of pinosylvin, were detected in serum at total concentration of 7−73 μM, confirming the bioavailability of pine knot extract derived lignans and stilbenoids. In summary, our data indicates that pine knot extract is a novel and cost-effective source of resveratrol, methyl pinosylvin and other bioactive lignans and stilbenoids. Pine knot extract shows anticarcinogenic efficacy in preclinical prostate cancer model, and our in vitro data suggests that compounds derived from the extract may have potential as novel chemosensitizers to TRAIL. These findings promote further research on health-related applications of wood biochemicals.  相似文献   
39.
The usefulness of different enzyme and immunohistochemical stains to distinguish reversible and irreversible myocardial cell injury after experimental coronary artery occlusion of varying duration and reperfusion with or without superoxide dismutase as adjunct was investigated. Biopsies or parts of the infarcted and non-infarcted area were rapidly frozen and sectioned in series for enzyme and immunohistochemical evaluation. Sections were stained for the demonstration of phosphorylase, myofibrillar ATPase and mitochondrial oxidative enzymes and also with periodic acid-Schiff, alizarin red S and routine histological stains. Other sections in series were stained with antibodies against fibronectin and the intermediate filament proteins desmin and vimentin. In 49 biopsies a blind quantitative estimation of the area stained for fibronectin, phosphorylase and alizarin red S was performed and evaluated statistically. Phosphorylase, periodic acid-Schiff, fibronectin and alizarin red S allowed delineation of affected myocardium after 30 min of ischaemia followed by reperfusion whereas with the other stains, affected myocardium was readily detectable only after 60 or 90 min of ischaemia followed by reperfusion as well as after 24 h of ischaemia without reperfusion. The immunostaining for fibronectin was very distinct and inversely related to the phosphorylase activity. We show that fibronectin is an excellent marker for damaged cells and that these positively stained myocytes are necrotic as confirmed ultrastructurally. Using alizarin red S as a marker of calcium accumulation in myocytes, a marked discrepancy was observed between the area of fibronectin-containing myocytes and that of myocytes stained by alizarin red S. Calcium accumulation in mitochondria is thus not a prerequisite for myocyte necrosis but does occur only in some of the irreversibly damaged cells. Of special interest is the finding that there was a significant reduction of intracellular calcium in pigs where superoxide dismutase had been used as an adjunct at reperfusion, thus supporting the theory that free radicals do play a role during reperfusion of ischaemic myocardium.  相似文献   
40.
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