[Objectives] To investigate the anti-tumor activity of Sedum bulbiferum Makino in vitro,and establish a HPLC method for determination of quercetin and kaempferol in S. bulbiferum. [Methods] The inhibitory activities o...[Objectives] To investigate the anti-tumor activity of Sedum bulbiferum Makino in vitro,and establish a HPLC method for determination of quercetin and kaempferol in S. bulbiferum. [Methods] The inhibitory activities of different extracts and total flavonoids of S. bulbiferum on proliferation of three kinds of cancer cells( Hep G2,EC109,SW480) were tested by MTT assay. HPLC method for determination of quercetin and kaempferol in S. bulbiferum was established. [Results]The growth and proliferation of the three kinds of cancer cells were all significantly inhibited by ethyl acetate fraction and total flavonoids isolated from S. bulbiferum. With each extraction concentration increasing,stronger anti-tumor activity was found. The linear ranges of quercetin and kaempferol were 0. 03-0. 36 μg( R = 0. 999 9) and0. 08-0. 96 μg( R = 0. 999 9),and the average recoveries were 98. 90%( RSD = 1. 15%) and 98. 27%( RSD = 1. 70%),respectively.[Conclusions]S. bulbiferum has significant anti-tumor activity in vitro. The HPLC method established was accurate,reproducible,and could be used for quality control of this crude drug.展开更多
In this paper, we use RTP/RTCP over unreliable UDP to realize the transportation of real time streaming. Meanwhile, according to the transmission feedback and network parameters, we analyze and calculate the network d...In this paper, we use RTP/RTCP over unreliable UDP to realize the transportation of real time streaming. Meanwhile, according to the transmission feedback and network parameters, we analyze and calculate the network delay, packet loss and RTT (round trip time) to determine the network state. Finally, we propose a streaming media transmission ??control scheme which could sense the network state and quickly adjust the rate of the sending side. It takes congestion, packet loss rate into comprehensive consideration and improves the overall performance of 3G network stream media.展开更多
文摘[Objectives] To investigate the anti-tumor activity of Sedum bulbiferum Makino in vitro,and establish a HPLC method for determination of quercetin and kaempferol in S. bulbiferum. [Methods] The inhibitory activities of different extracts and total flavonoids of S. bulbiferum on proliferation of three kinds of cancer cells( Hep G2,EC109,SW480) were tested by MTT assay. HPLC method for determination of quercetin and kaempferol in S. bulbiferum was established. [Results]The growth and proliferation of the three kinds of cancer cells were all significantly inhibited by ethyl acetate fraction and total flavonoids isolated from S. bulbiferum. With each extraction concentration increasing,stronger anti-tumor activity was found. The linear ranges of quercetin and kaempferol were 0. 03-0. 36 μg( R = 0. 999 9) and0. 08-0. 96 μg( R = 0. 999 9),and the average recoveries were 98. 90%( RSD = 1. 15%) and 98. 27%( RSD = 1. 70%),respectively.[Conclusions]S. bulbiferum has significant anti-tumor activity in vitro. The HPLC method established was accurate,reproducible,and could be used for quality control of this crude drug.
文摘In this paper, we use RTP/RTCP over unreliable UDP to realize the transportation of real time streaming. Meanwhile, according to the transmission feedback and network parameters, we analyze and calculate the network delay, packet loss and RTT (round trip time) to determine the network state. Finally, we propose a streaming media transmission ??control scheme which could sense the network state and quickly adjust the rate of the sending side. It takes congestion, packet loss rate into comprehensive consideration and improves the overall performance of 3G network stream media.
