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<正> 由于嚴重急性呼吸綜合征(SARS)的免疫病理機制尚未闡明,目前尚無有效藥物或治療方法能夠控制這種疾病。為了探討 SARS 發病的免疫學機制,我們研究了 SARS 患者外周血細胞因子與趨化因子的表達譜以及肺和淋巴組織的免疫病理改變。采用液相芯片技術,動態掃描了23例診斷明確的 SARS 患者血中14種細胞因子與趨化因子;應用反轉錄 PCR、免疫組化和免疫熒光技術對 SARS 死亡患者經尸體解剖的肺和淋巴組織進行免疫病理學觀察。本研究結果顯示,在 SARS 發病早期,血中干擾素可誘導的相對分子質量為10 000的蛋白(interferon-inducible protein-10,IP-10)水平明顯增高,并且在病情進展期保持高水平,與病情轉歸相

在實際工程可靠度分析中,得到極限狀態方程的解析表達式是非常困難的。提出一種基于數值模擬、BP網絡和優化技術三者相結合的可靠度分析方法,以模擬實際工程中常見的功能函數不能明確的可靠度計算問題。可靠度分析中,可直接應用現有的確定性有限元程序。給出平面框架和地下隧洞圍巖穩定的可靠度分析算例,計算中可考慮基本變量之間的相關性和基本變量的不同概型分布。數值結果表明,該方法具有較好的效率和精度。Usually it is very difficult to get an analytical equation of limit state for reliability analysis of the stability of tunnel. So, based on numerical simulation, BP network and optimal technique, a reliability analysis method is put forward to calculate the reliability index and test point. This method can simulate the reliability problems with implicit performance functions in actual engineering. On calculation reliability, the deterministic FEM programs can be used directly. Two illustrative examples are presented in this paper. The first example deals with reliability of a frame structure, and the second one studies the stability of a tunnel under the initial stress effect. In the calculation, the Young抯 modulus, friction angle and cohesion are treated as random variables and different probability distributions with these random variables and the correlation among them are considered. Comparisons with other methods show that the proposed method is very efficient and reasonably accurate.