The effects of solarisation using clear, UV stabilized, 25μm low density polyethylene mulching combined with soil amendment of chicken manures 12 th^-1, mixed fungicides of Metalaxyl 2 g-Benlate 1.5 g L^-l, Biocontro...The effects of solarisation using clear, UV stabilized, 25μm low density polyethylene mulching combined with soil amendment of chicken manures 12 th^-1, mixed fungicides of Metalaxyl 2 g-Benlate 1.5 g L^-l, Biocontrol agent of Trichoderma harzianum （T.h.） and NPK fertilizer 180 Kg h^-1, on the survived micro and macrocondia of Fusarium proliferatum （Matsushita） Nirenberg were ascertained during summer 2008. Mulched treatments within 45 and 60 days significantly reduced viable propagules to 6 and 3.4 × l03 cfu1 g soil, respectively at 5 cm depth followed by 15 and 30 cm soil depth. Natural heating of dry soil reduced an initial population of 76 × 10^3 to 46.73, 49 and 49.13 × 103 cfu＇lg soil at 5, 15 and 30 cm depth, respectively. Therefore, Fusarium proliferatum reduced by 85.29 and 89.22% within 45 and 60 days compared to 38% in control aired soil. Application of mulching with T. harzianum caused a worthwhile reduction 84.37% in viable propagules, solar with low doses of Metalaxyl-Benlate further reduced Fusarium propagules at all depths 95.5%. Combining chicken manures proved its reduction of fungi cfu at 5 cm depth only, whereas NPK amendments failed in their reduction effects at various depths. However, almost 95% reduction in Fusarium propagules was achieved at various soil depths when combining Met.-Ben., with soil mulching. Combining T.h. was also proved to be significant in reducing fungus inoculum by 88.58, 96.06% at 5 and 15 cm depth. Generally, manures and NPK fertilizers amended soil found equally effective in reducing cfu of Fusarium at 5 and 15 cm depth similar to polyethylene mulching for both solar duration.展开更多
Ultrasound has been widely used in clinics. Cellular responses to low-intensity ultrasound are parameter-dependent. Proper parameter setting is vital to its exact use. To get guidelines for parameter setting, lowinten...Ultrasound has been widely used in clinics. Cellular responses to low-intensity ultrasound are parameter-dependent. Proper parameter setting is vital to its exact use. To get guidelines for parameter setting, lowintensity ultrasound stimulation on the proliferation and reproductivity of Hep G2 and 3T3 cells in vitro was examined with a 1.06 MHz-generator by changing the parameters(including intensity, pulse repetition frequency and duty cycle)in a wide range. Cell viability and reproductivity at different time after sonication were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and colony formation assay to indicate timerelated proliferation. The results illustrate that ultrasound irradiation at 0.4—0.8 W/cm^2 and high pulse repetition frequency(100 Hz)can facilitate cell proliferation, while above 0.8 W/cm^2 would resist it. The extent of resistance closely correlated with duty cycle and pulse repetition frequency. Resistance effect at low pulse repetition frequency(1 Hz)is greater than that at high pulse repetition frequency(100 Hz)and not time-related. The influence of high pulse repetition frequency is time-accumulated, indicating cellular process involved. These findings would provide valuable guidelines for the application of low-intensity ultrasound in stem cell transformation and tissue engineering.展开更多
文摘The effects of solarisation using clear, UV stabilized, 25μm low density polyethylene mulching combined with soil amendment of chicken manures 12 th^-1, mixed fungicides of Metalaxyl 2 g-Benlate 1.5 g L^-l, Biocontrol agent of Trichoderma harzianum （T.h.） and NPK fertilizer 180 Kg h^-1, on the survived micro and macrocondia of Fusarium proliferatum （Matsushita） Nirenberg were ascertained during summer 2008. Mulched treatments within 45 and 60 days significantly reduced viable propagules to 6 and 3.4 × l03 cfu1 g soil, respectively at 5 cm depth followed by 15 and 30 cm soil depth. Natural heating of dry soil reduced an initial population of 76 × 10^3 to 46.73, 49 and 49.13 × 103 cfu＇lg soil at 5, 15 and 30 cm depth, respectively. Therefore, Fusarium proliferatum reduced by 85.29 and 89.22% within 45 and 60 days compared to 38% in control aired soil. Application of mulching with T. harzianum caused a worthwhile reduction 84.37% in viable propagules, solar with low doses of Metalaxyl-Benlate further reduced Fusarium propagules at all depths 95.5%. Combining chicken manures proved its reduction of fungi cfu at 5 cm depth only, whereas NPK amendments failed in their reduction effects at various depths. However, almost 95% reduction in Fusarium propagules was achieved at various soil depths when combining Met.-Ben., with soil mulching. Combining T.h. was also proved to be significant in reducing fungus inoculum by 88.58, 96.06% at 5 and 15 cm depth. Generally, manures and NPK fertilizers amended soil found equally effective in reducing cfu of Fusarium at 5 and 15 cm depth similar to polyethylene mulching for both solar duration.
基金Supported by the Natural Science Foundation of Tianjin(No.12JCYBJC18300)
文摘Ultrasound has been widely used in clinics. Cellular responses to low-intensity ultrasound are parameter-dependent. Proper parameter setting is vital to its exact use. To get guidelines for parameter setting, lowintensity ultrasound stimulation on the proliferation and reproductivity of Hep G2 and 3T3 cells in vitro was examined with a 1.06 MHz-generator by changing the parameters(including intensity, pulse repetition frequency and duty cycle)in a wide range. Cell viability and reproductivity at different time after sonication were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and colony formation assay to indicate timerelated proliferation. The results illustrate that ultrasound irradiation at 0.4—0.8 W/cm^2 and high pulse repetition frequency(100 Hz)can facilitate cell proliferation, while above 0.8 W/cm^2 would resist it. The extent of resistance closely correlated with duty cycle and pulse repetition frequency. Resistance effect at low pulse repetition frequency(1 Hz)is greater than that at high pulse repetition frequency(100 Hz)and not time-related. The influence of high pulse repetition frequency is time-accumulated, indicating cellular process involved. These findings would provide valuable guidelines for the application of low-intensity ultrasound in stem cell transformation and tissue engineering.
