Browsing by Author "Hsieh, Tsung-Chih"

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Diosgenin, a Plant-Derived Sapogenin, Exhibits Antiviral Activity in Vitro against Hepatitis C Virus
(2011-04-01)
Wang, Ya-Jean
;
Pan, Kao-Lu
;
Hsieh, Tsung-Chih
;
Chang, Teng-Yuan
;
Lin, Wen-Hsing
Diosgenirr (3 beta-hydroxy-5-spirostene, 1); a plant-derived sapogenin, is used as a dietary: supplement However, the biological effects of 1 related to viral replication remain unexplored. In this study, the effects of 1 on hepatitis C virus (HCV) replication were evaluated. Based on a reporter-based HCV subgenomic replicon system, 1 was found to inhibit HCV replication at low micromolar concentrations. The EC(50) (concentration at which 50% of HCV replication is inhibited) of 1 was 3.8 mu M No cellular toxicity was observed at this concentration.,Diosgenin, (1) also significantly reduced the levels of viral,RNA and viral proteins as evaluated by quantitative real-time reverse :transcriptase PCR and Western blot analysis, respectively. In addition, in an HCV antiviral system more closely aligned to all steps involved in the HCV infection and life cycle, 1 totally abolished HCV replication at 20 mu M. Moreover, 1 reduced the phosphorylation of signal transducer and activator of transcription 3. A combination of 1:and interferon-alpha exerted an additive effect on the resultant anti-HCV activity.
Traffic Aggregation for Overload Control in LTE-based Machine Type Communications
(2016-01-01)
Hsieh, Tsung-Chih
;
Chen, Yaw-Chung
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資訊工程學系
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Department of Computer Science
Machine-Type Communication (MTC) is the communication between machines through either wired or wireless links without human intervention. The LTE cellular networks with global connectivity and wide range of coverage provide infrastructure for developing MTC applications. However, the differences between conventional communications and MTC bring new technical challenges to the LTE. In this article, we investigated the problem of congestion in LTE caused by MTC, and proposed a traffic aggregation solution that aggregates the traffic generated by massive MTC devices on local side to reduce the total access attempts to the LTE base station. We evaluated the performance of the proposed scheme thru the simulation, the results show the remarkable performance improvement in reducing the number of access attempts while not causing too much overhead on the devices.