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排序方式: 共有54条查询结果,搜索用时 15 毫秒
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Buckwheat (Fagopyrum esculentum Moench) protein (BWP) exhibits hypocholesterolemic activity in several animal models by increasing fecal excretion of neutral and acidic sterols. In the current study, the ability of BWP to disrupt micelle cholesterol solubility by sequestration of cholesterol was investigated. When BWP (0.2%) was incubated with cholesterol and micelle lipid components prior to micelle formation, cholesterol solubility was reduced 40%. In contrast, cholesterol solubility was not decreased when BWP (0.2%) was incubated after micelle formation and incorporation of soluble cholesterol. Buckwheat flour, from which BWP was derived, had no significant effect on cholesterol solubility. Cholesterol uptake in Caco-2 cells from micelles made in the presence of BWP (0.2%) was reduced by 47, 36, 35, and 33% when compared with buckwheat flour, bovine serum albumin, casein, and gelatin, respectively. Reduction in cholesterol uptake in Caco-2 cells was dose-dependent, with maximum reductions at 0.1-0.4% BWP. In cholesterol-binding experiments, 83% of the cholesterol was associated with an insoluble BWP fraction, indicating strong cholesterol-binding capacity that disrupts solubility and uptake by Caco-2 cells. 相似文献
3.
Fleming DG Arseneau DJ Sukhorukov O Brewer JH Mielke SL Schatz GC Garrett BC Peterson KA Truhlar DG 《Science (New York, N.Y.)》2011,331(6016):448-450
The neutral muonic helium atom may be regarded as the heaviest isotope of the hydrogen atom, with a mass of ~4.1 atomic mass units ((4.1)H), because the negative muon almost perfectly screens one proton charge. We report the reaction rate of (4.1)H with (1)H(2) to produce (4.1)H(1)H + (1)H at 295 to 500 kelvin. The experimental rate constants are compared with the predictions of accurate quantum-mechanical dynamics calculations carried out on an accurate Born-Huang potential energy surface and with previously measured rate constants of (0.11)H (where (0.11)H is shorthand for muonium). Kinetic isotope effects can be compared for the unprecedentedly large mass ratio of 36. The agreement with accurate quantum dynamics is quantitative at 500 kelvin, and variational transition-state theory is used to interpret the extremely low (large inverse) kinetic isotope effects in the 10(-4) to 10(-2) range. 相似文献
4.
R.Jess Jørgensen 《Veterinary parasitology》1980,7(2):153-167
A field experiment was conducted over two grazing seaons with calves on a permanent pasture in order to follow the pattern of infection with Dictyocaulus viviparus. Infective larvae persisted during the first, but not during the second, winter of observation. By means of the agar-bile herbage technique, a moderate first peak of infection was demonstrated in the pasture 2–3 weeks before the appearance of respiratory signs in the calves. Fluctuations in faecal larval output were reflected in the herbage contamination with infective larvae close to faecal pats. This, as well as the horizontal dispersion of larvae in the pasture, took place in less than a week. The proportion of lungworm larvae recovered away from faeces was low during a period of dry and hot weather while herbage sampling at two-hour intervals during two days showed an increase in herbage contamination with lungworm larvae, but not with trichostrongyle larvae between 10 a.m. and 12 noon.The infectivity of the pasture was monitored by tracer calves and compared with the results of the pasture sampling. The general course of the infection in the calves and in the pasture was the results of interaction between them. In addition, the pasture infection was influenced by climate and the infection in the calves by the development of immunity. The course of infection in individuals appeared to have an influence on the general course of the infection through the contamination of the pasture. 相似文献
5.
ABSTRACT: African horse sickness is an economically highly important non-contagious but infectious Orbivirus disease that is transmitted by various species of Culicoides midges. The equids most severely affected by the virus are horses, ponies, and European donkeys; mules are somewhat less susceptible, and African donkeys and zebra are refractory to the devastating consequences of infection. In recent years, Bluetongue virus, an Orbivirus similar to African horse sickness, which also utilises Culicoides spp. as its vector, has drastically increased its range into previously unaffected regions in northern Europe, utilising indigenous vector species, and causing widespread economic damage to the agricultural sector. Considering these events, the current review outlines the history of African horse sickness, including information concerning virus structure, transmission, viraemia, overwintering ability, and the potential implications that an outbreak would have for Ireland. While the current risk for the introduction of African horse sickness to Ireland is considered at worst 'very low', it is important to note that prior to the 2006 outbreak of Bluetongue in northern Europe, both diseases were considered to be of equal risk to the United Kingdom ('medium-risk'). It is therefore likely that any outbreak of this disease would have serious socio-economic consequences for Ireland due to the high density of vulnerable equids and the prevalence of Culicoides species, potentially capable of vectoring the virus. 相似文献
6.
Carrots ( Daucus carota L.) contain phytochemicals including carotenoids, phenolics, polyacetylenes, isocoumarins, and sesquiterpenes. Purple carrots also contain anthocyanins. The anti-inflammatory activity of extracts and phytochemicals from purple carrots was investigated by determining attenuation of the response to lipopolysaccharide (LPS). A bioactive chromatographic fraction (Sephadex LH-20) reduced LPS inflammatory response. There was a dose-dependent reduction in nitric oxide production and mRNA of pro-inflammatory cytokines (IL-6, IL-1beta, TNF-alpha) and iNOS in macrophage cells. Protein secretions of IL-6 and TNF-alpha were reduced 77 and 66% in porcine aortic endothelial cells treated with 6.6 and 13.3 microg/mL of the LH-20 fraction, respectively. Preparative liquid chromatography resulted in a bioactive subfraction enriched in the polyacetylene compounds falcarindiol, falcarindiol 3-acetate, and falcarinol. The polyacetylenes were isolated and reduced nitric oxide production in macrophage cells by as much as 65% without cytotoxicity. These results suggest that polyacetylenes, not anthocyanins, in purple carrots are responsible for anti-inflammatory bioactivity. 相似文献
7.
Stephen Jess Sally L
B Kidd Trevor McCallion David I Matthews 《Pest management science》2000,56(12):995-1004
This is the third survey of control practices for ectoparasites on sheep farms in Northern Ireland, providing data comparative to those recorded in previous surveys in 1981 and 1988. Data relating to all aspects of ectoparasite control were collected from 210 farms representing 4% of the total sheep population. Quantitative data have been adjusted to provide accurate estimates of total pesticide usage. Since the previous survey in 1988, the number of sheep farms in Northern Ireland has increased by 10% to 11 692 with a consequent 39% increase in sheep population to 2.9 million. Despite this level of expansion, the total quantity of organophosphorus compounds used for ectoparasite control has remained approximately constant at 7–8 tonnes. The report considers that compulsory sheep‐dipping, prescribed since 1970 and revoked in 1993, impacted significantly on subsequent ectoparasite control practices and consequent pesticide usage. During 1997, approximately 20% of sheep farmers relied on alternative methods to control ectoparasites, including injectable formulations of avermectins and pour‐on formulations of insect growth regulators and pyrethroids. Dipping formulations containing pyrethroid compounds, which accounted for <1% of treatments in 1988, increased to 9% in 1997. Previously, regulatory sheep‐dipping periods were specified during the autumn months, which tended to increase dipping frequency. The majority of farmers dipping sheep during the summer strictly for blowfly maggot (Diptera: Calliphoridae) control were required to perform additional compulsory sheep‐dipping during the autumn. Withdrawal of compulsory sheep‐dipping has allowed farmers to synchronise dipping practices to control the major ectoparasites of sheep at a single dipping occasion. An estimated 7.5 × 106 litres of surplus dipwash required disposal and there were approximately equal numbers of farmers disposing dipwash immediately after sheep‐dipping or on occasions up to and including subsequent dipping. The decline in the number of farmers who allowed dipwash to run‐off into soakaways or surrounding soil observed in 1988 continued in 1997. The majority of farmers used tractor‐operated pumps to dispose of dipwash into slurry tanks for subsequent disposal onto permanent pasture. © Crown copyright 2000. Reproduced with the permission of Her Majesty's Stationery Office. Published for SCI by John Wiley & Sons, Ltd. 相似文献
8.
Feliciano RP Shea MP Shanmuganayagam D Krueger CG Howell AB Reed JD 《Journal of agricultural and food chemistry》2012,60(18):4578-4585
The 4-(dimethylamino)cinnamaldehyde (DMAC) assay is currently used to quantify proanthocyanidin (PAC) content in cranberry products. However, this method suffers from issues of accuracy and precision in the analysis and comparison of PAC levels across a broad range of cranberry products. Current use of procyanidin A2 as a standard leads to an underestimation of PACs content in certain cranberry products, especially those containing higher molecular weight PACs. To begin to address the issue of accuracy, a method for the production of a cranberry PAC standard, derived from an extraction of cranberry (c-PAC) press cake, was developed and evaluated. Use of the c-PAC standard to quantify PAC content in cranberry samples resulted in values that were 2.2 times higher than those determined by procyanidin A2. Increased accuracy is critical for estimating PAC content in relationship to research on authenticity, efficacy, and bioactivity, especially in designing clinical trials for determination of putative health benefits. 相似文献
9.
10.
R. Jess Jørgensen 《Veterinary parasitology》1975,1(1):61-67
A technique is described in which Dictyocaulus larvae are stimulated to activity and isolated free from any debris by migration in agar gel.Microscopical recognition and enumeration was carried out on stained parasitic larvae while the free living species were decolourized.The technique was found suitable for routine use. Its efficiency was tested by adding larvae to the debris from parasite free herbage samples. Average recovery rates for Dictyocaulus viviparus and D. filaria larvae were found to be 60 and 80% respectively. 相似文献