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A series of asymmetrical thio-bis-N-methylcarbamate derivatives were synthesised by combining 3,4-methylenedioxyphenyl N-methylcarbamate with different N-methylcarbamates. Some of these derivatives combined good insecticidal activity against the housefly with reduced acute oral toxicity to mice. The thio-bis-N-methylcarbamates obtained exhibited a lower anti-cholinesterase activity than the more toxic of the two carbamate moieties contained in each combination. The weak synergism of piperonyl butoxide on the insecticidal activity of the derivatives suggests the possibility of a self synergism phenomenon caused by the 3,4-methylenedioxyphenyl group.  相似文献   
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Cattle, ethanol, and biogas: Does closing the loop make economic sense?   总被引:1,自引:0,他引:1  
The recent surge in US ethanol production has led to an increase in the amount of byproduct feed available to cattle producers. The impetus behind the increase in ethanol production is US policy to increase the production and use of renewable fuels. Manure from cattle production can also be used to produce a renewable fuel: methane. By co-locating a cattle feedlot with an existing ethanol plant, there may be synergies between ethanol, methane and cattle production. Byproduct from the ethanol plant can be fed to feeder cattle, manure from the cattle used in methane production, and the methane used as an energy source in the ethanol plant. Alternatively, methane can be used to generate electricity. We investigate the economic advisability of these systems. Using cost estimates for construction and operating a feedlot and anaerobic digester for methane production, we project revenues and costs over a 20-year time period. Our findings are consistent with studies that have considered just cattle production and methane production. The investment required to build a slatted-floor feedlot and concrete anaerobic digester cannot be justified under existing economic conditions. An increase in renewable fuel/electricity subsidies of at least $0.053 per kW h or $72 per 1000 m3 of methane are required to just break even when methane is used to produce electricity or is burned for thermal energy, respectively.  相似文献   
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Cellular immune responses of peripheral blood lymphocytes to canine distemper virus and measles virus were determined in vaccinated or infected gnotobiotic dogs, using the technique of syncytia inhibition. Cross-reactivity between viruses was detected in both groups of dogs. Peak responses in vaccinated dogs occurred 11 days after vaccination and declined to base-line levels by 3 weeks, whereas responses in infected dogs were present 30 days after inoculation. Fractionation experiments with peripheral blood lymphocytes indicated that synctia inhibition is probably mediated by T lymphocytes.  相似文献   
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