Diphenyl-2, 2-dicyanoethylene reacts with 10-methyl-9, 10-dihydroacridine in deaerated acetonitrile under irradiation with l>320 nm to give the coupling product 1, 1-diphenyl-1-(10-methyl-9-acridinyl)-2, 2-dicyanoe...Diphenyl-2, 2-dicyanoethylene reacts with 10-methyl-9, 10-dihydroacridine in deaerated acetonitrile under irradiation with l>320 nm to give the coupling product 1, 1-diphenyl-1-(10-methyl-9-acridinyl)-2, 2-dicyanoethane, which has been characterized by X-ray crystallographic, MS and NMR analyses.展开更多
Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein fr...Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein from Lb. brevis and then cloned into down-stream of lactose-inducible promoter of an integrative plasmid, pIlac. After electroporation into Lb. casei CECT5276, PCR using the genomic DNA of the recombinant lactobacillus as template was performed to confirm whether the hCGβ gene had been integrated into the genome. Radioimmunoassay (RIA) was used to determine the level of hCGβ in the supernatant and the cell lysate. Results The hCGβ was integrated into the genome of Lb. casei CECT5276. The highest concentration of hCGβ in the culture supernatant amounted to 440 mIU/mL 21 h after lactose induction. About 2/3 of the abstract Objective proteins were excreted into the supernatant. Conclusion We have obtained stable and efficient hCGβ excretion in Lb. casei, which was inducible by lactose.展开更多
AIM: To express Hp ureC gene in E.coli, a fragment from Hp ureC was amplified by the polymerase chain reaction and was cloned into E.coli expressing plasmid vector--- pBV220. This study lay the foundation for further ...AIM: To express Hp ureC gene in E.coli, a fragment from Hp ureC was amplified by the polymerase chain reaction and was cloned into E.coli expressing plasmid vector--- pBV220. This study lay the foundation for further studies of its functions. METHODS : An 1173bp gene fragment was amplified by the polymerase chain reaction. The template DNA was purified from Hp clinical strain. The gene fragment was digested by BamH I and EcoR I and cloned into pGEM-3Zf (-) plasmid. Its sequence was determined by autosequencing instrument from two directions. Then the gene fragment was cloned into pBV220. Subsequently the DH5 a was transformed by pBV220/ureC and was induced by heat when temperature reached 42"C. The form of expressed protein was analyzed to learn that in which form the recombinant protein was expressed. The thin layer chromatogram was used to scan thegel to learn that the quantity of the expressed protein. Antigenicity of the expressed protein wasconfirmed by ELISA and DIGFA. RESULTS z 95% of the DNA sequence we got is the same as that ofHp strain M60398. A Mr 44000 recombinant protein was induced by heat when temperature reached 42℃. The molecular mass of the expressed ureC gene is coincide with expected. The expressed proteinaccounts for 24.8% of the whole protein of the host bactria. Although most of the recombinant proteinsare inclusion bodies in host bactria after translation, there does exist certain quantity of solvable proteins in the supernatant of bacteria lysate. CONCLUSION：Recombinant H.pylori urease C protein is expressed in E.coli and the expressed protein has the antigenicity ofureC. Our study lays the foundation for further studies of the functions of lip ureC.展开更多
Without any additional cost, all the disks on the nodes of a cluster can be connected together through CEFT-PVFS, an RAID-10 style parallel file system, to provide a multi-GB/s parallel I/O performance. I/O response t...Without any additional cost, all the disks on the nodes of a cluster can be connected together through CEFT-PVFS, an RAID-10 style parallel file system, to provide a multi-GB/s parallel I/O performance. I/O response time is one of the most important measures of quality of service for a client. When multiple clients submit data-intensive jobs at the same time, the response time experienced by the user is an indicator of the power of the cluster. In this paper, a queuing model is used to analyze in detail the average response time when multiple clients access CEFT-PVFS. The results reveal that response time is with a function of several operational parameters. The results show that I/O response time decreases with the increases in I/O buffer hit rate for read requests, write buffer size for write requests and the number of server nodes in the parallel file system, while the higher the I/O requests arrival rate, the longer the I/O response time. On the other hand, the collective power of a large cluster supported by CEFT-PVFS is shown to be able to sustain a steady and stable I/O response time for a relatively large range of the request arrival rate. Keywords PVFS - parallel I/O - I/O response time This work is supported by the National Natural Science Foundation of China (Grant No.60273074), the Special Foundation for National Excellent Ph.D. Thesis, and Huo YingDong Education Foundation (Grant No.91068).Dan Feng is a professor of College of Computer Science at Huazhong University of Science and Technology (HUST), China. She obtained the Ph.D. degree from HUST in 1997. Her current interests are computer architecture, redundant array independent disks, mass storage, and information technology.Hong Jiang is an associate professor of Department of Computer Science and Engineering at University of Nebraska-Lincoln, Lincoln, Nebraska. He obtained the Ph.D. degree from Texas A&M University in 1991. His current interests are computer architecture, parallel I/O, parallel and distributed processing, performance evaluation and real-time systems.Yi-Feng Zhu is a Ph.D. candidate of Department of Computer Science and Engineering at University of Nebraska-Lincoln, Lincoln, Nebraska. He obtained the M.S. degree from University of Nebraska-Lincoln in 2002. His research interests cover computer architecture, network storage, parallel I/O and cluster computing.展开更多
文摘Diphenyl-2, 2-dicyanoethylene reacts with 10-methyl-9, 10-dihydroacridine in deaerated acetonitrile under irradiation with l>320 nm to give the coupling product 1, 1-diphenyl-1-(10-methyl-9-acridinyl)-2, 2-dicyanoethane, which has been characterized by X-ray crystallographic, MS and NMR analyses.
文摘Objective To construct a recombinant lactobacillus (Lb.) strain excreting the human chorionic gonadotropin beta-subunit (hCGβ) Methods The hCGβ cDNA was ligated to the signal peptide sequence of S-layer protein from Lb. brevis and then cloned into down-stream of lactose-inducible promoter of an integrative plasmid, pIlac. After electroporation into Lb. casei CECT5276, PCR using the genomic DNA of the recombinant lactobacillus as template was performed to confirm whether the hCGβ gene had been integrated into the genome. Radioimmunoassay (RIA) was used to determine the level of hCGβ in the supernatant and the cell lysate. Results The hCGβ was integrated into the genome of Lb. casei CECT5276. The highest concentration of hCGβ in the culture supernatant amounted to 440 mIU/mL 21 h after lactose induction. About 2/3 of the abstract Objective proteins were excreted into the supernatant. Conclusion We have obtained stable and efficient hCGβ excretion in Lb. casei, which was inducible by lactose.
文摘AIM: To express Hp ureC gene in E.coli, a fragment from Hp ureC was amplified by the polymerase chain reaction and was cloned into E.coli expressing plasmid vector--- pBV220. This study lay the foundation for further studies of its functions. METHODS : An 1173bp gene fragment was amplified by the polymerase chain reaction. The template DNA was purified from Hp clinical strain. The gene fragment was digested by BamH I and EcoR I and cloned into pGEM-3Zf (-) plasmid. Its sequence was determined by autosequencing instrument from two directions. Then the gene fragment was cloned into pBV220. Subsequently the DH5 a was transformed by pBV220/ureC and was induced by heat when temperature reached 42"C. The form of expressed protein was analyzed to learn that in which form the recombinant protein was expressed. The thin layer chromatogram was used to scan thegel to learn that the quantity of the expressed protein. Antigenicity of the expressed protein wasconfirmed by ELISA and DIGFA. RESULTS z 95% of the DNA sequence we got is the same as that ofHp strain M60398. A Mr 44000 recombinant protein was induced by heat when temperature reached 42℃. The molecular mass of the expressed ureC gene is coincide with expected. The expressed proteinaccounts for 24.8% of the whole protein of the host bactria. Although most of the recombinant proteinsare inclusion bodies in host bactria after translation, there does exist certain quantity of solvable proteins in the supernatant of bacteria lysate. CONCLUSION：Recombinant H.pylori urease C protein is expressed in E.coli and the expressed protein has the antigenicity ofureC. Our study lays the foundation for further studies of the functions of lip ureC.
基金国家自然科学基金，the Special Foundation for National Excellent Ph.D. Thesis, and Huo YingDong Education Foundation
文摘Without any additional cost, all the disks on the nodes of a cluster can be connected together through CEFT-PVFS, an RAID-10 style parallel file system, to provide a multi-GB/s parallel I/O performance. I/O response time is one of the most important measures of quality of service for a client. When multiple clients submit data-intensive jobs at the same time, the response time experienced by the user is an indicator of the power of the cluster. In this paper, a queuing model is used to analyze in detail the average response time when multiple clients access CEFT-PVFS. The results reveal that response time is with a function of several operational parameters. The results show that I/O response time decreases with the increases in I/O buffer hit rate for read requests, write buffer size for write requests and the number of server nodes in the parallel file system, while the higher the I/O requests arrival rate, the longer the I/O response time. On the other hand, the collective power of a large cluster supported by CEFT-PVFS is shown to be able to sustain a steady and stable I/O response time for a relatively large range of the request arrival rate. Keywords PVFS - parallel I/O - I/O response time This work is supported by the National Natural Science Foundation of China (Grant No.60273074), the Special Foundation for National Excellent Ph.D. Thesis, and Huo YingDong Education Foundation (Grant No.91068).Dan Feng is a professor of College of Computer Science at Huazhong University of Science and Technology (HUST), China. She obtained the Ph.D. degree from HUST in 1997. Her current interests are computer architecture, redundant array independent disks, mass storage, and information technology.Hong Jiang is an associate professor of Department of Computer Science and Engineering at University of Nebraska-Lincoln, Lincoln, Nebraska. He obtained the Ph.D. degree from Texas A&M University in 1991. His current interests are computer architecture, parallel I/O, parallel and distributed processing, performance evaluation and real-time systems.Yi-Feng Zhu is a Ph.D. candidate of Department of Computer Science and Engineering at University of Nebraska-Lincoln, Lincoln, Nebraska. He obtained the M.S. degree from University of Nebraska-Lincoln in 2002. His research interests cover computer architecture, network storage, parallel I/O and cluster computing.
