The rice stem borer, Chilo suppressalis Walker is one of the most important insect pests on rice in Asia, north Africa and southern Europe. Transgenic Bt rice has been developed in the laboratory with good resistance ...The rice stem borer, Chilo suppressalis Walker is one of the most important insect pests on rice in Asia, north Africa and southern Europe. Transgenic Bt rice has been developed in the laboratory with good resistance to this pest and other Lepidopteran insects, which will provide a possible alternative tool for this pest control. The full-length cDNAs encoding an aminopeptidase N （CsAPN） and a cadherin （CsCad） were cloned from C. suppressalis. CsAPN showed common features of, and high identities to, other insect APNs in its deduced amino acid sequence. Although a full-length cDNA encoding cadherin-like protein has been reported in GenBank, the newly isolated cadherin here （CsCad） showed some differences in its amino acid sequence, especially at the 7th cadherin repeat region （CR7）, which indicated the newly isolated CsCad might be another allele. CsAPN and CsCad were successfully expressed in insect Tn cells, and the blot analysis showed these two proteins could bind Bt toxin CrylAb. The results will provide valuable information for the studies of toxin mode of action and the possible toxin resistance mechanisms in this pest.展开更多
Here,Ag2S nanoparticles on reduced graphene oxide（Ag2S NPs/RGO） nanocomposites with relatively good distribution are synthesized for the first time by conversing Ag NPs/RGO to Ag2S NPs/RGO via a facile hydrothermal ...Here,Ag2S nanoparticles on reduced graphene oxide（Ag2S NPs/RGO） nanocomposites with relatively good distribution are synthesized for the first time by conversing Ag NPs/RGO to Ag2S NPs/RGO via a facile hydrothermal sulfurization method.As an noval catalyst for the reduction of 4-nitrophenol（4-NP）,it only takes 5 min for Ag2S NPs/RGO to reduce 98% of 4-NP,and the rate constant of the composites is almost 13 times higher than that of Ag NPs/RGO composites.The high catalytic activity of Ag2S NPs/RGO can be attributed to the following three reasons：（1） Like metal complex catalysts,the Ag2S NPs is also rich with metal center Ag（δ^＋）,with pendant base S（δ） close to it,and thus the Ag and basic S function as the electron-acceptor and proton-acceptor centers,respectively,which facilitates the catalyst reaction;（2）RGO features the high adsorption ability toward 4-NP which provides a high concentration of 4-NP near the Ag2S NPs;and（3） electron transfer from RGO to Ag2S NPs,facilitating the uptake of electrons by 4-NP molecules.展开更多
文摘The rice stem borer, Chilo suppressalis Walker is one of the most important insect pests on rice in Asia, north Africa and southern Europe. Transgenic Bt rice has been developed in the laboratory with good resistance to this pest and other Lepidopteran insects, which will provide a possible alternative tool for this pest control. The full-length cDNAs encoding an aminopeptidase N （CsAPN） and a cadherin （CsCad） were cloned from C. suppressalis. CsAPN showed common features of, and high identities to, other insect APNs in its deduced amino acid sequence. Although a full-length cDNA encoding cadherin-like protein has been reported in GenBank, the newly isolated cadherin here （CsCad） showed some differences in its amino acid sequence, especially at the 7th cadherin repeat region （CR7）, which indicated the newly isolated CsCad might be another allele. CsAPN and CsCad were successfully expressed in insect Tn cells, and the blot analysis showed these two proteins could bind Bt toxin CrylAb. The results will provide valuable information for the studies of toxin mode of action and the possible toxin resistance mechanisms in this pest.
文摘Here,Ag2S nanoparticles on reduced graphene oxide（Ag2S NPs/RGO） nanocomposites with relatively good distribution are synthesized for the first time by conversing Ag NPs/RGO to Ag2S NPs/RGO via a facile hydrothermal sulfurization method.As an noval catalyst for the reduction of 4-nitrophenol（4-NP）,it only takes 5 min for Ag2S NPs/RGO to reduce 98% of 4-NP,and the rate constant of the composites is almost 13 times higher than that of Ag NPs/RGO composites.The high catalytic activity of Ag2S NPs/RGO can be attributed to the following three reasons：（1） Like metal complex catalysts,the Ag2S NPs is also rich with metal center Ag（δ^＋）,with pendant base S（δ） close to it,and thus the Ag and basic S function as the electron-acceptor and proton-acceptor centers,respectively,which facilitates the catalyst reaction;（2）RGO features the high adsorption ability toward 4-NP which provides a high concentration of 4-NP near the Ag2S NPs;and（3） electron transfer from RGO to Ag2S NPs,facilitating the uptake of electrons by 4-NP molecules.
