IPTV用户在电信运营商的大力推动下快速增长,对带宽的要求也越来越高,运营商必须依附于现在的网络现状,对IPTV业务进行二层改造、资源规划,制定一系列业务开展规范,以满足业务及用户快速增长需求。对于运营商的管理人员、技术人员和装...IPTV用户在电信运营商的大力推动下快速增长,对带宽的要求也越来越高,运营商必须依附于现在的网络现状,对IPTV业务进行二层改造、资源规划,制定一系列业务开展规范,以满足业务及用户快速增长需求。对于运营商的管理人员、技术人员和装维人员而言,IPTV电视业务的维护与管理,一直是日常运维中的难点。结合早期互联网电视业务的运维经验,文章尝试对IPTV业务PPPOE(Point-to-Point Protocol Over Ethernet,以太网点对点协议)接入组播冗余应用进行研究,旨在提高IPTV业务接入可靠性,降低现有网络带宽资源的占用,提升IPTV电视的业务持续发展的能力。展开更多
The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （...The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.展开更多
The protecting effect of histidine on the photodamage of pigments and proteins of the isolated PSⅠ particles from the chloroplast of Spinacia oleracea L. during the strong illumination (2 300 μmol·m -2 ...The protecting effect of histidine on the photodamage of pigments and proteins of the isolated PSⅠ particles from the chloroplast of Spinacia oleracea L. during the strong illumination (2 300 μmol·m -2 ·s -1 ) was studied by spectroscopy and SDS_PAGE. The absorbance of PSⅠ particles decreased during the strong illumination treatment, but the decrease would be slowed down in the presence of externally added histidine after 30 min illumination. The decrease of CD (circular dichroism) signal intensities of PSⅠ particles also was slowed down by the added histidine after about 10 min illumination. The retarded protecting effect of the added histidine on the photobleaching of pigments of PSⅠ complexes implied that the mechanisms of photoinhibition of isolated PSⅠ complexes are different from early stage to later stage during the strong illumination treatment. In addition, the added histidine suppressed the decrease of 77 K fluorescence yield of PSⅠ particles during the illumination. SDS_PAGE showed that the added histidine not only protected the reaction center proteins of PSⅠ particles, but also protected other subunits of PSⅠ particles from degradation.展开更多
AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine. METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support prod...AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine. METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support productive HBV infection in vitro. Expression of HBsAg and HBeAg in infected HepG2 culture medium was detected by commercial enzyme immunoassays. HBV DNA replication intermediates were detected in infected cells by Southern hybridization and viral DNA load was determined by dot hybridization. RESULTS: IFN-γat 0.1 to 5μg/L efficiently down regulated HBsAg expression in transduced HepG2 cells. At 5μg/L, IFN-γalso suppressed HBV DNA replication in these cells. While treatment with a combination of lamivudine and IFN-γshowed no additive effect, sequential treatment first with lamivudine and then IFN-γwas found to be promising. In this culture system the best HBV suppression was observed with a pulse of 2μmol/L lamivudine for two days, followed by 1μg/L IFN-γfor another four days. Compared to treatment with lamivudine alone, the sequential use of 0.2μmol/L lamivudine for two days, followed by 5μg/L IFN-γfor six days showed a 72% reduction in HBV cccDNA pool. CONCLUSION: This in vitro study warrants further evaluation of a combination of IFN-γand lamivudine, especially in IFN-αnon-responder chronic hepatitis B patients. A reduced duration of lamivudine treatment would also restrict the emergence of drug-resistant HBV mutants.展开更多
Genome replication of reovirus occurs in cytoplasmic inclusion bodies called viral factories or viroplasms. The viral nonstructural protein uNS, encoded by genome segment M3, is not a component of mature virions, but ...Genome replication of reovirus occurs in cytoplasmic inclusion bodies called viral factories or viroplasms. The viral nonstructural protein uNS, encoded by genome segment M3, is not a component of mature virions, but is expressed to high levels in infected cells and is concentrated in the infected cell factory matrix. Recent studies have demonstrated that uNS plays a central role in forming the matrix of these structures, as well as in recruiting other components to them for putative roles in genome replication and particle assembly.展开更多
The stages of introduction in vitro culture of the local population of the kidney tea （Orthosiphon stamineus Bents） cultivated in the Georgia’s medicinal plant farm and the microclonal propagation, in particular, h...The stages of introduction in vitro culture of the local population of the kidney tea （Orthosiphon stamineus Bents） cultivated in the Georgia’s medicinal plant farm and the microclonal propagation, in particular, have been elaborated. The cultivation of explants was carried out on the Gamborg （B5） feeding area. The hormonal （BAP; Zn; NAA） composition of the feeding area and their concentrations have been selected; proliferation of buds in the basal part of the sprout has been achieved from the formed morphogenic tissue. The microclones by activating axillary meristem have been received.展开更多
文摘IPTV用户在电信运营商的大力推动下快速增长,对带宽的要求也越来越高,运营商必须依附于现在的网络现状,对IPTV业务进行二层改造、资源规划,制定一系列业务开展规范,以满足业务及用户快速增长需求。对于运营商的管理人员、技术人员和装维人员而言,IPTV电视业务的维护与管理,一直是日常运维中的难点。结合早期互联网电视业务的运维经验,文章尝试对IPTV业务PPPOE(Point-to-Point Protocol Over Ethernet,以太网点对点协议)接入组播冗余应用进行研究,旨在提高IPTV业务接入可靠性,降低现有网络带宽资源的占用,提升IPTV电视的业务持续发展的能力。
基金Project(51312JQ08)supported by the Pre-Research Foundation of China General Equipment DepartmentProject(NBPJ2013-4)supported by the Postdoctoral Science Foundation of Ningbo Branch of China Academy of Ordnance Science+1 种基金Project(bsh1402073)supported by the Postdoctoral Science Foundation of Zhejiang Province,ChinaProject(2014A610051)supported by the Ningbo Natural Science Foundation of China
文摘The bonding interface of 7B52 Al alloy laminated composite （ALC） fabricated by hot rolling was investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, scanning electron microscopy （SEM）, ultrasonic flaw detection （UFD）, and bonding strength tests. The results show that metallurgical bonding is achieved at the interface after composite rolling. The TEM analysis and tensile tests indicate that the 7B52 ALC plate combines high strength of the hard individual layer and good toughness of the soft individual layer. However, UFD technology and SEM analysis prove that the defects （thick oxide films, acid washed residues, air, oil and coarse particles） existing in the bonding interface are harmful to the bonding strength. To sum up, the composite roiling process is suitable for 7B52 ALC plate, and the content and size of the defects should be controlled strictly. Advanced surface treatment of each individual layer would be beneficial to further improve the bonding quality.
文摘The protecting effect of histidine on the photodamage of pigments and proteins of the isolated PSⅠ particles from the chloroplast of Spinacia oleracea L. during the strong illumination (2 300 μmol·m -2 ·s -1 ) was studied by spectroscopy and SDS_PAGE. The absorbance of PSⅠ particles decreased during the strong illumination treatment, but the decrease would be slowed down in the presence of externally added histidine after 30 min illumination. The decrease of CD (circular dichroism) signal intensities of PSⅠ particles also was slowed down by the added histidine after about 10 min illumination. The retarded protecting effect of the added histidine on the photobleaching of pigments of PSⅠ complexes implied that the mechanisms of photoinhibition of isolated PSⅠ complexes are different from early stage to later stage during the strong illumination treatment. In addition, the added histidine suppressed the decrease of 77 K fluorescence yield of PSⅠ particles during the illumination. SDS_PAGE showed that the added histidine not only protected the reaction center proteins of PSⅠ particles, but also protected other subunits of PSⅠ particles from degradation.
基金Supported by a grant from the Dabur Research Foundation, India and a Senior Research Fellowship of the CSIR, Gov. of India (to MKP)
文摘AIM: To evaluate the in vitro anti-HBV activity of recombinant human IFN-γ, alone and in combination with lamivudine. METHODS: A recombinant baculovirus-HBV/HepG2 culture system was developed which could support productive HBV infection in vitro. Expression of HBsAg and HBeAg in infected HepG2 culture medium was detected by commercial enzyme immunoassays. HBV DNA replication intermediates were detected in infected cells by Southern hybridization and viral DNA load was determined by dot hybridization. RESULTS: IFN-γat 0.1 to 5μg/L efficiently down regulated HBsAg expression in transduced HepG2 cells. At 5μg/L, IFN-γalso suppressed HBV DNA replication in these cells. While treatment with a combination of lamivudine and IFN-γshowed no additive effect, sequential treatment first with lamivudine and then IFN-γwas found to be promising. In this culture system the best HBV suppression was observed with a pulse of 2μmol/L lamivudine for two days, followed by 1μg/L IFN-γfor another four days. Compared to treatment with lamivudine alone, the sequential use of 0.2μmol/L lamivudine for two days, followed by 5μg/L IFN-γfor six days showed a 72% reduction in HBV cccDNA pool. CONCLUSION: This in vitro study warrants further evaluation of a combination of IFN-γand lamivudine, especially in IFN-αnon-responder chronic hepatitis B patients. A reduced duration of lamivudine treatment would also restrict the emergence of drug-resistant HBV mutants.
基金National Basic Research Program of China (973 Program) ( 2009CB118701)National Natural Scientific Foundation of China (30671615, 30871940)Innovation project of the Chinese Academy of Sciences(KSCX2-YW-N-021 to QF).
文摘Genome replication of reovirus occurs in cytoplasmic inclusion bodies called viral factories or viroplasms. The viral nonstructural protein uNS, encoded by genome segment M3, is not a component of mature virions, but is expressed to high levels in infected cells and is concentrated in the infected cell factory matrix. Recent studies have demonstrated that uNS plays a central role in forming the matrix of these structures, as well as in recruiting other components to them for putative roles in genome replication and particle assembly.
文摘The stages of introduction in vitro culture of the local population of the kidney tea （Orthosiphon stamineus Bents） cultivated in the Georgia’s medicinal plant farm and the microclonal propagation, in particular, have been elaborated. The cultivation of explants was carried out on the Gamborg （B5） feeding area. The hormonal （BAP; Zn; NAA） composition of the feeding area and their concentrations have been selected; proliferation of buds in the basal part of the sprout has been achieved from the formed morphogenic tissue. The microclones by activating axillary meristem have been received.
