The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity...The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity are expected to be beneficial for reducing diarrhoea caused by pathogens in weaned piglets, the effects of such materials on porcine intestinal cells have not been investigated in detail. Therefore, this work evaluated the immunoregulatory functions of microbial feed materials in porcine intestinal immune and epithelial cells. Porcine immune cells isolated from Peyer’s patches and mesenteric lymph nodes were stimulated with six different feed materials containing microorganisms, and evaluated for lymphocyte mitogenicity and cytokine inductions. In addition, porcine intestinal epithelial cells were stimulated with the materials before treatment with heat-killed enterotoxigenic Escherichia coli (ETEC), and analyzed for the proinflammatory cytokine expressions. The material containing Bifidobacterium thermophilum significantly augmented lymphocytes’ mitogenicity and also induced a high expression of IL-2, IL-6 and IFN-γ in immune cells, and inhibited ETEC-induced overexpression of IL-6 and IL-8 via regulation of Toll-like receptor signaling. These results suggest that this feed material stimulates intestinal epithelial and immune cells to exert immunoregulation, suggesting that this feed is expected to contribute to promoting the health of piglets without using antimicrobial feed materials.展开更多
Axial deep creep-feed grinding machining technology is a high efficiency process method of engineering ceramics materials, which is an original method to process the cylindrical ceramics materials or hole along its ax...Axial deep creep-feed grinding machining technology is a high efficiency process method of engineering ceramics materials, which is an original method to process the cylindrical ceramics materials or hole along its axis. The analysis of axial force and edge fracture proved the cutting thickness and feed rate could be more than 5-10 mm and 200 mm/min respectively in once process, and realized high efficiency, low-cost process of engineering ceramics materials. Compared with high speed-deep grinding machining, this method is also a high efficiency machining technology of engineering ceramics materials as well as with low cost. In addition, removal mechanism analyses showed that both median/radial cracks and lateral cracks appeared in the part to be removed, and the processed part is seldom destroyed, only by adjusting the axial force to control the length of transverse cracks.展开更多
On the basis of theoretical analysis and cold model test, the material motion locus and the particle size which can be separated in the swirl shaft preheater was stud-ied. A new calculation method for separation effic...On the basis of theoretical analysis and cold model test, the material motion locus and the particle size which can be separated in the swirl shaft preheater was stud-ied. A new calculation method for separation efficiency based on the meterial size distribution curve of charge and dis-charge stock from the shaft is discussed in this paper. The ex-perimental results show the material separation is due to in-teraction of both the centrifugation and the gravity. When the inlet gas velocity is a constant, the separation efficiency will be raised as the load of batch feeding inreases. If the load of batch feeding is a constant, the separation efficiency will be decreased together with the elevation of the inlet gas. The loss of shaft resistence is increased when the separation effi-ciency is raised. In our experiment the suitable separation ef-ficiency of the shaft is about 70 percent.展开更多
文摘The establishment of drug-free feeding systems has been required for secure and healthy livestock production. Although functional feed materials containing microorganisms as alternatives to enhance intestinal immunity are expected to be beneficial for reducing diarrhoea caused by pathogens in weaned piglets, the effects of such materials on porcine intestinal cells have not been investigated in detail. Therefore, this work evaluated the immunoregulatory functions of microbial feed materials in porcine intestinal immune and epithelial cells. Porcine immune cells isolated from Peyer’s patches and mesenteric lymph nodes were stimulated with six different feed materials containing microorganisms, and evaluated for lymphocyte mitogenicity and cytokine inductions. In addition, porcine intestinal epithelial cells were stimulated with the materials before treatment with heat-killed enterotoxigenic Escherichia coli (ETEC), and analyzed for the proinflammatory cytokine expressions. The material containing Bifidobacterium thermophilum significantly augmented lymphocytes’ mitogenicity and also induced a high expression of IL-2, IL-6 and IFN-γ in immune cells, and inhibited ETEC-induced overexpression of IL-6 and IL-8 via regulation of Toll-like receptor signaling. These results suggest that this feed material stimulates intestinal epithelial and immune cells to exert immunoregulation, suggesting that this feed is expected to contribute to promoting the health of piglets without using antimicrobial feed materials.
基金the National Natural Science Foundation of China(Nos.51075309 and 51275372)the Twelfth five-year National Defence Pre-research Projects(No.51318020210)Wuhan High-Tech Development Project Foundation(No.201110921299)
文摘Axial deep creep-feed grinding machining technology is a high efficiency process method of engineering ceramics materials, which is an original method to process the cylindrical ceramics materials or hole along its axis. The analysis of axial force and edge fracture proved the cutting thickness and feed rate could be more than 5-10 mm and 200 mm/min respectively in once process, and realized high efficiency, low-cost process of engineering ceramics materials. Compared with high speed-deep grinding machining, this method is also a high efficiency machining technology of engineering ceramics materials as well as with low cost. In addition, removal mechanism analyses showed that both median/radial cracks and lateral cracks appeared in the part to be removed, and the processed part is seldom destroyed, only by adjusting the axial force to control the length of transverse cracks.
文摘On the basis of theoretical analysis and cold model test, the material motion locus and the particle size which can be separated in the swirl shaft preheater was stud-ied. A new calculation method for separation efficiency based on the meterial size distribution curve of charge and dis-charge stock from the shaft is discussed in this paper. The ex-perimental results show the material separation is due to in-teraction of both the centrifugation and the gravity. When the inlet gas velocity is a constant, the separation efficiency will be raised as the load of batch feeding inreases. If the load of batch feeding is a constant, the separation efficiency will be decreased together with the elevation of the inlet gas. The loss of shaft resistence is increased when the separation effi-ciency is raised. In our experiment the suitable separation ef-ficiency of the shaft is about 70 percent.