Biomedical subjects

Fan Zhai

Publications and source records attributed to Fan Zhai.

5 recordsLinked to original sources

PubMed2006

Rate-distortion optimized hybrid error control for real-time packetized video transmission.

The problem of application-layer error control for real-time video transmission over packet lossy networks is commonly addressed via joint source-channel coding (JSCC), where source coding and forward error correction (FEC) are jointly designed to compensate for packet losses. In this paper, we consider hybrid application-layer error correction consisting of FEC and retransmissions. The study is carried out in an integrated joint source-channel coding (IJSCC) framework, where error resilient source coding, channel coding, and error concealment are jointly considered in order to achieve the best video delivery quality. We first show the advantage of the proposed IJSCC framework as compared to a sequential JSCC approach, where error resilient source coding and channel coding are not fully integrated. In the USCC framework, we also study the performance of different error control scenarios, such as pure FEC, pure retransmission, and their combination. Pure FEC and application layer retransmissions are shown to each achieve optimal results depending on the packet loss rates and the round-trip time. A hybrid of FEC and retransmissions is shown to outperform each component individually due to its greater flexibility.

Algorithms↗

PubMed2006

VAPOR: variance-aware per-pixel optimal resource allocation.

Characterizing the video quality seen by an end-user is a critical component of any video transmission system. In packet-based communication systems, such as wireless channels or the Internet, packet delivery is not guaranteed. Therefore, from the point-of-view of the transmitter, the distortion at the receiver is a random variable. Traditional approaches have primarily focused on minimizing the expected value of the end-to-end distortion. This paper explores the benefits of accounting for not only the mean, but also the variance of the end-to-end distortion when allocating limited source and channel resources. By accounting for the variance of the distortion, the proposed approach increases the reliability of the system by making it more likely that what the end-user sees, closely resembles the mean end-to-end distortion calculated at the transmitter. Experimental results demonstrate that variance-aware resource allocation can help limit error propagation and is more robust to channel-mismatch than approaches whose goal is to strictly minimize the expected distortion.

Algorithms↗

PubMed2003

[Clinical study on treatment of patients with upper digestive tract malignant tumors of middle and late stage with Ginkgo biloba exocarp polysaccharides capsule preparation].

OBJECTIVE: To observe the clinical efficacy of Ginkgo biloba exocarp polysaccharides (GBEP) capsule preparation in treating upper digestive tract malignant tumors of middle and late stage. METHODS: Eighty-six patients of the upper digestive tract malignant tumors were treated with GBEP capsule preparation taken orally. The clinical symptoms and the qualities of life of the patients with single GBEP and combined with operation, radiotherapy or intervention chemotherapy were observed. The tumor size was measured by electronic gastroscope before and after treatment with single GBEP. Objective response rate (RR) of the tumor was calculated. The survival period of patient was observed. The changes of blood routine examination in the patients treated with radiotherapy were observed. RESULTS: GBEP preparation could markedly improve the patients'clinical symptoms. Karnofsky scoring of the patients markedly increased after treatment. There were 2 CR (complete response, 6.3%), 22 PR (partial response, 68.8%)and 5 SD (stable disease, 15.6%) of 32 cases with single GBEP preparation. The survival periods of the 32 cases were markedly prolonged. The preparation could relieve the inhibited hematopietic function and the weight loss due to radiotherapy. CONCLUSION: GBEP capsule preparation has some definite therapeutic effects on upper digestive tract malignant tumors of middle and late stage.

Administration, Oral↗

PubMed2003

Therapeutic mechanism of ginkgo biloba exocarp polysaccharides on gastric cancer.

AIM: To study the therapeutic mechanism of Ginkgo biloba exocarp polysaccharides (GBEP) on gastric cancer. METHODS: Thirty patients with gastric cancer were treated with oral GBEP capsules. The area of tumors was measured by electron gastroscope before and after treatment, then the inhibitory and effective rates were calculated. The ultrastructures of tumor cells were examined by transmissional electron microscope. Cell culture, MTT, flow cytometry were performed to observe proliferation, apoptosis and changes of relevant gene expression of human gastric cancer SGC-7901 cells. RESULTS: Compared with the statement before treatment, GBEP capsules could reduce the area of tumors, and the effective rate was 73.4%. Ultrastructural changes of the cells indicated that GBEP could induce apoptosis and differentiation in tumor cells of patients with gastric cancer. GBEP could inhibit the growth of human gastric cancer SGC-7901 cells following 24-72 h treatment in vitro at 10-320 mg/L, which was dose- and time-dependent. GBEP was able to elevate the apoptosis rate and expression of c-fos gene, but reduce the expression of c-myc and bcl-2 genes also in a dose-dependent manner. CONCLUSION: The therapeutic mechanism of GBEP on human gastric cancer may relate to its effects on the expression of c-myc, bcl-2 and c-fos genes, which can inhibit proliferation and induce apoptosis and differentiation of tumor cells.

Administration, Oral↗

PubMed2002

Effect of ambient conditions on the antibacterial activity of antibacterial agent based on sodium titanium phosphate.

OBJECTIVE: To investigate the effects of ambient conditions on the antibacterial activity of inorganic antibacterial agent based on sodium titanium phosphate. METHODS: The number of live E. Coli ATCC 44113 was counted after the suspension was shaken and incubated in flask with antibacterial agent under ambient conditions. RESULT: The number of live bacteria increased when the concentration of bacteria increased in the range of 1.2 x 10(2) to 1.2 x 10(8) cfu/ml. The antibacterial activity increased with the increase of ambient temperature in the range of 16 approximately 46 degrees C, showing good antibacterial activity at human body temperature. With the increase of the concentrations of co-existing NaCl and protein, the antibacterial activity was found to decrease at first and level off at 0.01 g/ml and 0.0005 g/ml respectively. CONCLUSION: The antibacterial agent has to be used together with organic antibacterial agent in order to achieve good antibacterial effect when the ambient bacterial concentration is high. The antibacterial agent is promising to be used in the preparation of antibacterial cloth because it is highly effective at body temperature and expected to remain antibacterial in perspiration.

Anti-Bacterial Agents↗