利用有限元分析预警经阴道分娩瘢痕子宫破裂风险

目的 应用有限元法分析瘢痕子宫受力与瘢痕厚度及位置的关系,研究瘢痕子宫破裂风险因素.方法 首先基于孕期为40周孕妇子宫尺寸应用SolidWorks建立瘢痕厚度和位置可变的子宫三维模型,然后在ANSYS软件中设置宫内压力,压力范围为4.83～ 23.9 kPa,计算子宫受力.结果 在宫缩过程中,最大应力位于子宫瘢痕处,瘢...     

Turning back from the brink: Detecting an impending regime shift in time to avert it

Ecological regime shifts are large, abrupt, long-lasting changes in ecosystems that often have considerable impacts on human economies and societies. Avoiding unintentional regime shifts is widely regarded as desirable, but prediction of ecological regime shifts is notoriously difficult. Recent research indicates that changes in ecological time series (e.g., increased variability and autocorrelation) could potentially serve as early warning indicators of impending shifts. A critical question, however, is whether such indicators provide sufficient warning to adapt management to avert regime shifts. We examine this question using a fisheries model, with regime shifts driven by angling (amenable to rapid reduction) or shoreline development (only gradual restoration is possible). The model represents key features of a broad class of ecological regime shifts. We find that if drivers can only be manipulated gradually management action is needed substantially before a regime shift to avert it; if drivers can be rapidly altered aversive action may be delayed until a shift is underway. Large increases in the indicators only occur once a regime shift is initiated, often too late for management to avert a shift. To improve usefulness in averting regime shifts, we suggest that research focus on defining critical indicator levels rather than detecting change in the indicators. Ideally, critical indicator levels should be related to switches in ecosystem attractors; we present a new spectral density ratio indicator to this end. Averting ecological regime shifts is also dependent on developing policy processes that enable society to respond more rapidly to information about impending regime shifts.     

医疗风险管理预警体系的构建研究

通过对比国内外医疗风险预警的研究现状，借鉴其他行业建立预警机制的方法，对医疗风险预警的步骤流程、指标体系构建、模型应用提出构想。     

经皮氧监测对急性呼吸窘迫综合征的早期预警及指导治疗

目的观察经皮氧（PtcO2）监测对急性呼吸窘迫综合征（ANDS）的早期预警及指导治疗作用。方法92例急性肺损伤（ALI）患者随机分为经皮氧监测组及非经皮氧监测组（各46例）。2组病人人院后均给予常规治疗，发生ARDS时给予加强治疗。经皮氧监测组以PtcO2／FiO2≤250mmHg考虑发生ARDS，非经皮氧监测组每8h监测Pa02，以PacO2／Fi02≤200mmHg考虑发生ARDS。比较2组病人ARDS的发生率、诊断ARDS的时间、诊断ARDS时PacO2／FiO2、有创机械通气的发生率。结果2组病人的ARDS发生率的差异无统计学意义（P〉0．05）。经皮氧监测组ARDS的诊断时间早于非经皮氧监测组（P〈0．05），诊断ARDS时的PacO2／FiO2高于非经皮氧监测治疗组（P〈0．05），诊断后有创机械通气的发生率低于非经皮氧监测组（P〈0．05）。结论经皮氧监测组能够较早预警ARDS的发生并有效指导治疗，改善预后。     

我国药品安全预警现状及对策研究

采用文献、访谈调研的方法，综合分析国内外药品安全预警相关的监管工作现状,探讨我国药品安全预警系统的构建模式。国内外药品安全预警特点差异明显，各有侧重。建议建立并完善我国药品安全预警系统，实时监测药品安全隐患。     

胰腺癌临床预警指标和筛查方案研究

目的 探索胰腺癌的预警指标，建立筛查方案。方法 于1996年10月-2000年6月及2002年2月．2004年3月采用以医院为基础病例对照研究，对胰腺癌患者270例，胰腺良性疾病131例，非胰腺癌良性消化道疾病191例，正常人272例，进行各种影像检查（包括B超、CT、ERCP、EUS、DSA）和实验室检查（包括血CA199和CA242、大便K-ras、p53，胰液、十二指肠液K-ras突变检测）进行评估。结果 胰腺癌影像诊断中EUS及ERCP具有最高准确性，K-ras在胰腺癌胰液中突变率为84．4％，十二指肠液中为83．3％，大便中为83．3％，肿瘤标志物CA199和CA242诊断胰腺癌敏感性分别为78．4％和68．3％。结论 大便K-ras、CA199、US的联合试验可使敏感性提高，作为第一步胰腺癌筛选指标，如果可疑则进行CT检查，EUS和ERCP等有创伤性检查作为第三步。