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51.
Griesbeck-Zilch B Meyer HH Kühn CH Schwerin M Wellnitz O 《Journal of dairy science》2008,91(6):2215-2224
Pathogens invading the mammary gland cause a complex signaling network that activates the early immune defense and leads to an outcome of inflammation symptoms. To examine the importance of mammary epithelial cells in these regulations and interactions resulting in a pathogen-related course of mastitis, we characterized the mRNA expression profile of key molecules of the innate immune system by quantitative real-time PCR. Mammary gland epithelial cells isolated on d 42 of lactation from 28 first-lactation Holstein dairy cows were cultured separately under standardized conditions and treated for 1, 6, and 24 h with heat-inactivated gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria. Both pathogens increased mRNA expression patterns of proteins involved in pathogen recognition such as Toll-like receptors and nuclear factor-κ B, whereas gram-negatives acted as a stronger stimulus. Furthermore, this could be confirmed by the expression profile of the proinflammatory cytokines tumor necrosis factor alpha, IL-1 beta, IL-6, and chemokines such as IL-8 and RANTES (regulated upon activation, normal T-cell expressed and secreted). Remarkably, at a low level of mRNA expression after 1 h of treatment these cytokines and chemokines were expressed at a significantly higher level in Staphyloccocus aureus than in Escherichia coli affected cells. Lactoferrin showed a deviating expression pattern to pathogen stimulation (i.e., at the 1-h measuring point Escherichia coli induced a higher mRNA expression, whereas the highest level was reached after 24 h of stimulation with Staphylococcus aureus). Complement factor 3 was the only measured factor that responded equally to both microorganisms. Our data emphasize the role of mammary epithelial cells in the immune defense of the udder and confirm their contribution to pathogen-related different courses of mastitis. 相似文献
52.
53.
Inulin as texture modifier in dairy products 总被引:1,自引:0,他引:1
In this review we will describe the application of inulin for texture improvement in a variety of dairy applications as this is one of the most important application areas. The effects of inulin in these systems as a fat replacer, i.e. how it can be used to mimic the features of fat for mouthfeel and creaminess, and how these effects may be related to changes in rheology of the food system will be described for liquid, semi-solid and solid dairy products. 相似文献
54.
Transport of chemical and microbial compounds from known wastewater discharges: potential for use as indicators of human fecal contamination 总被引:3,自引:0,他引:3
Glassmeyer ST Furlong ET Kolpin DW Cahill JD Zaugg SD Werner SL Meyer MT Kryak DD 《Environmental science & technology》2005,39(14):5157-5169
The quality of drinking and recreational water is currently (2005) determined using indicator bacteria. However, the culture tests used to analyze forthese bacteria require a long time to complete and do not discriminate between human and animal fecal material sources. One complementary approach is to use chemicals found in human wastewater, which would have the advantages of (1) potentially shorter analysis times than the bacterial culture tests and (2) being selected for human-source specificity. At 10 locations, water samples were collected upstream and at two successive points downstream from a wastewaster treatment plant (WWTP); a treated effluent sample was also collected at each WWTP. This sampling plan was used to determine the persistence of a chemically diverse suite of emerging contaminants in streams. Samples were also collected at two reference locations assumed to have minimal human impacts. Of the 110 chemical analytes investigated in this project, 78 were detected at least once. The number of compounds in a given sample ranged from 3 at a reference location to 50 in a WWTP effluent sample. The total analyte load at each location varied from 0.018 microg/L at the reference location to 97.7 microg/L in a separate WWTP effluent sample. Although most of the compound concentrations were in the range of 0.01-1.0 microg/L, in some samples, individual concentrations were in the range of 5-38 microg/L. The concentrations of the majority of the chemicals present in the samples generally followed the expected trend: they were either nonexistent or at trace levels in the upstream samples, had their maximum concentrations in the WWTP effluent samples, and then declined in the two downstream samples. This research suggests that selected chemicals are useful as tracers of human wastewater discharge. 相似文献
55.
The objective was to investigate the effect of changing the flooring in the alleys of a barn from slatted concrete to slatted rubber mats on hoof disorders and animal hygiene in 44 loose-housed Brown Swiss dairy cows. Cows were examined for disorders of the hind hooves (hemorrhages, white line fissures, ulcers, heel horn erosion, and digital dermatitis) and for skin lesions. The dirtiness of the animals and of the floor was recorded. Climatic (temperature, humidity) and ammonia gas conditions were measured. Evaluations were carried out when the cows were housed on a concrete slatted floor and after 4 and 10 mo on soft flooring (slatted rubber mats, 29-mm thick). The anatomical portion of claw (medial, lateral), number of lactations (parity), and days in milk were included as covariates in the statistical model. Changing the flooring from slatted concrete to slatted rubber mats increased the score for white line fissures [1.0 ± 0.3 (concrete) vs. 2.5 ± 0.4 (10 mo rubber mats)] and influenced air humidity (i.e., the difference in the absolute humidity between the inside and outside of the barn increased from 1.5 ± 0.1 to 1.7 ± 0.2 g/m3), whereas the other hoof disorders, skin lesions (score of 8.7 ± 0.3), the dirtiness of the animals (score of 5.9 ± 0.3), and the floor (score of 2.1 ± 0.1), and ammonia gas concentration (2.6 ± 0.3 mg/kg) were not affected (overall scores or measures; mean ± SE). Lateral claws were more affected (except for heel horn erosion) than medial claws (estimated effects between 1.3 ± 0.2 and 3.0 ± 0.6). Parity influenced hoof disorders (except for hemorrhages) and skin lesions (estimated effects between −0.6 ± 0.3 and 0.5 ± 0.2). Days in milk influenced hoof disorders, but had no effect on skin lesions and on the dirtiness of the animal. Irrespective of floor type, the slots (2.6 ± 0.1) were dirtier than the slats (1.6 ± 0.1). In conclusion, covering slatted concrete flooring with slatted rubber mats partially impaired hoof health but did not influence skin lesions or the dirtiness of the cows or the floor. Similar results were found for climatic conditions, as ammonia gas concentration was not affected, but absolute humidity increased in the barn when rubber mats were present. 相似文献
56.
57.
The extraction of wheat starch with ethanol reduced the protein content from 0.4 to 0.3%. Wheat starch extracted with 1% SDS containing 1% 2-ME or with 1% SDS gave no staining with amido black, indicating that most of starch surface protein has been separated. TLC of lipids extracted from starch without gelatinization showed that ethanol extracted considerable amounts of starch lipids such as lysophosphatidyl choline, lysophosphatidyl ethanolamine and free fatty acids. After extraction with SDS and especially with SDS + 1% 2-ME only some starch granules were deformed. In this starch some changes have been observed also on the granules surface by REM. The extraction resulted also in considerable changes in rheological properties of extracted starches. The starch samples were characterized thermodynamically also. 相似文献
58.
W. W. Meyer 《Journal of the American Ceramic Society》1938,21(3):75-79
The constant in Arrhenius’equation, when applied to the vitrification process of feldspathic whiteware bodies was calculated, using known data. Proceeding from this point, a mathematical expression for the amount of reaction taking place in a normal whiteware mixture, heated according to a given schedule, was obtained. Formulas were also derived for calculating heating schedules of various rates of temperature rise and lengths of soaking period productive of a given amount of reaction. The calculated amounts of reaction necessary to vitrify feldspathic whiteware bodies were correlated with the RO contents of the bodies. Data on the physical properties of variously heat-treated bodies are given to substantiate the validity of the formulas. A chart is given by means of which many heat-treatment problems can be solved without using the mathematical formulas. 相似文献
59.
P. B. Reichardt J. P. Bryant B. R. Mattes T. P. Clausen F. S. Chapin III M. Meyer 《Journal of chemical ecology》1990,16(6):1941-1959
Palatabilities of parts and growth stages of balsam poplar (Populus balsamifera) to snowshoe hares (Lepus americanus) are related to concentrations of specific plant metabolites that act as antifeedants. Buds are defended from hares by cineol, benzyl alcohol, and (+)-α-bisabolol. Internodes are defended by 6-hydroxycylohexenone (6-HCH) and salicaldehyde. Although defense of interaodes depends upon both compounds, the defense of juvenile internodes is principally related to salicaldehyde concentration; the defense of internode current annual growth is principally related to 6-HCH concentration. The concentration of 6-HCH can be supplemented by the hydrolysis of phenol glycosides when plant tissue is disrupted, raising the possibility of a dynamic element of the chemical defense of poplar. 相似文献
60.
Retardation of the gasification reaction of carbon with oxygen by SO2 was observed. Rates of oxidation were determined by thermal gravimetric analysis (TGA) of a nuclear graphite in the temperature range of 550–700°C, and of a coconut charcoal in the temperature range of 400–505°C. The oxidant gases were dry air containing 0–6% SO2. Reduction of the rate by SO2 varied with burn-off. Differential thermal analysis (DTA) was also applied to detect the retardation effect of SO2. The technique of infrared internal reflection spectroscopy (IRS) was used to examine the surface species of reacted charcoal samples. Absorption bands were assigned to surface carbonyls, lactones, and a chemisorbed SO2 in the form of sulfate. Chemisorption of SO2 was attributed to cause the retardation of the oxidation reaction. 相似文献