Carbohydrate chains are the principal antigens by which Bacillus thuringiensis（Bt） identify receptor proteins. The interaction between the antigen and Bt causes a pore in the membrane of midgut epithelial cells of i...Carbohydrate chains are the principal antigens by which Bacillus thuringiensis（Bt） identify receptor proteins. The interaction between the antigen and Bt causes a pore in the membrane of midgut epithelial cells of insects. Receptor proteins, such as aminopeptidase N and alkaline phosphatase, are glycoproteins. Cadherin is another cell surface receptor protein which has potential glycosylation sites. Glycosyltransferase is very important for the synthesis and modification of receptor proteins. It can indirectly influence the function of Bt. The 1 950 bp full-length c DNA encoding β-1,3-galactosyltransferase was cloned from the the midgut of Helicoverpa armigera by degenerative PCR combined with RACE techniques（GAL-Harm, Gen Bank accession no.： GQ904195.1） with two potential N-glycosylation sites（^157NNTI^160 and ^272NKTL^275）. Protein sequence alignments revealed that H. armigera β-1,3-galactosyltransferase shared high identity with β-1,3-galactosyltransferase in other insect species. The expression level of the β-1,3-galactosyltransferase gene in Cry1Ac-resistant H. armigera larvae was 9.2-fold higher than that in susceptible strain. The function of β-1,3-galactosyltransferase was investigated using RNAi technique. The result showed Cry1 Ac enhanced the toxicity against the si RNA-treated larvae compared with non-si RNA-treated ones, which indicated β-1,3-galactosyltransferase played an important role for the insecticidal toxicity of Cry1 Ac in H. armigera.展开更多
Parallel-wiring cables are often used in multi-phase AC aircraft Electrical Power Systems(EPSs).However,it complicates the ac resistance estimation.To solve this issue,an analytical resistance calculation method for p...Parallel-wiring cables are often used in multi-phase AC aircraft Electrical Power Systems(EPSs).However,it complicates the ac resistance estimation.To solve this issue,an analytical resistance calculation method for parallel-wiring cables in multi-phase EPS was proposed.Firstly,the existing calculation formula of proximity factor was optimized,and the calculation error was reduced from 16%to 2%when two conductors are close to each other.Afterwards,the superposition effect on current density distribution between multi-conductors was considered based on orthogonal decomposition method,and the position of the equivalent charged points were easily determined.Finally,the ac resistance calculation formula was derived according to characteristics of parallel-wiring strategy,and the general ac resistance calculation methods of multi-phase parallel-wiring cables were presented.The proposed approach considerably enhances the applicability of ac resistance analytical calculation method for multi-conductor cables.Thanks to the accuracy of the proposed method,it can be used in many cases to avoid case-by-case simulation work and facilitate efficient system design and analysis.展开更多
基金supported by the Key Technologies R&D Program of China during the 12th Five-Year Plan period (2012BAD19B05)the National Natural Science Foundation of China (30971921,31321004)
文摘Carbohydrate chains are the principal antigens by which Bacillus thuringiensis（Bt） identify receptor proteins. The interaction between the antigen and Bt causes a pore in the membrane of midgut epithelial cells of insects. Receptor proteins, such as aminopeptidase N and alkaline phosphatase, are glycoproteins. Cadherin is another cell surface receptor protein which has potential glycosylation sites. Glycosyltransferase is very important for the synthesis and modification of receptor proteins. It can indirectly influence the function of Bt. The 1 950 bp full-length c DNA encoding β-1,3-galactosyltransferase was cloned from the the midgut of Helicoverpa armigera by degenerative PCR combined with RACE techniques（GAL-Harm, Gen Bank accession no.： GQ904195.1） with two potential N-glycosylation sites（^157NNTI^160 and ^272NKTL^275）. Protein sequence alignments revealed that H. armigera β-1,3-galactosyltransferase shared high identity with β-1,3-galactosyltransferase in other insect species. The expression level of the β-1,3-galactosyltransferase gene in Cry1Ac-resistant H. armigera larvae was 9.2-fold higher than that in susceptible strain. The function of β-1,3-galactosyltransferase was investigated using RNAi technique. The result showed Cry1 Ac enhanced the toxicity against the si RNA-treated larvae compared with non-si RNA-treated ones, which indicated β-1,3-galactosyltransferase played an important role for the insecticidal toxicity of Cry1 Ac in H. armigera.
基金co-supported by the National Natural Science Foundation of China(No.51877102)the Innovation Foundation of Jiangsu Province,China(No.KYLX16_0365。
文摘Parallel-wiring cables are often used in multi-phase AC aircraft Electrical Power Systems(EPSs).However,it complicates the ac resistance estimation.To solve this issue,an analytical resistance calculation method for parallel-wiring cables in multi-phase EPS was proposed.Firstly,the existing calculation formula of proximity factor was optimized,and the calculation error was reduced from 16%to 2%when two conductors are close to each other.Afterwards,the superposition effect on current density distribution between multi-conductors was considered based on orthogonal decomposition method,and the position of the equivalent charged points were easily determined.Finally,the ac resistance calculation formula was derived according to characteristics of parallel-wiring strategy,and the general ac resistance calculation methods of multi-phase parallel-wiring cables were presented.The proposed approach considerably enhances the applicability of ac resistance analytical calculation method for multi-conductor cables.Thanks to the accuracy of the proposed method,it can be used in many cases to avoid case-by-case simulation work and facilitate efficient system design and analysis.
