Six Sigma® can be dangerous to your health

Six Sigma^® is a popular quality program that has been applied to clinical laboratory assays. Sigma is calculated as (TEa ? bias)/CV and these sigma numbers are often claimed as a sole measure of quality based on medical requirements. But these sigma calculations do not account for all results. An additional set of wider limits must be added, such that all data are accounted for. This gives a minimum of three zones: zone A, where 95% of the data should be; zone C, where there should be no data; and zone B, where 5% of the data is allowed. An additional problem is that sigma calculations are often based on valid analytical data, meaning that pre-analytical and post-analytical errors are excluded. Also, samples that are flagged by the system and produce no results are, of course, excluded, but delayed results can cause patient harm. A better measure of assay quality can be provided by a failure mode effects analysis (FMEA), which attempts to assess the probability of failure and its severity for every possible failure mode. In this paper, an example of what is entailed is described for two failure modes and the overall process is outlined. The amount of effort required for a full FMEA is beyond virtually any clinical laboratory. Some compromises are suggested. Calculating sigma values, which have little meaning about patient harm, is not recommended.     

The mathematization of the individual sciences — Revisited

We recall major findings of a systematic investigation of the mathematization of the individual sciences, conducted by the author in Bielefeld some 35 years ago under the direction of Klaus Krickeberg, and confront them with recent developments in physics, medicine, economics, and spectral geometry. Dedicated to the 80th birthday of Klaus Krickeberg     

续断和龟板的红外光谱研究

续断和龟板是两种典型的中药材,续断是植物药材,龟板是动物药材。本文采用傅立叶变换红外光谱法测定了续断和龟板的红外光谱图。续断和龟板的红外光谱区别十分明显,但也有相同或相似的峰存在。续断中主要成分为淀粉、纤维素、生物碱、木质素等;龟板中主要成分为脂肪、胶质、钙、磷等。此外续断有跌打损伤的主治药效可能与三萜类化合物的生理活性有关;龟板具有止痛功效可能与含有挥发油成分有关。     

中药川芎和赤芍配伍规律的方法研究

提出应用HPLC-PAD-MS研究中药配伍多种化学成分的基本思路,指出应用色谱保留时间、紫外光谱及质谱等多信息、综合对照的方法确定合煎液中各峰的归属,从而进一步研究了中药的配伍规律.首先建立了一套稳定、重复而可靠的液相色谱分析方法进行分离,再用统一的分析方法对分离的色谱图进行数据处理.在HPLC-PAD-MS分析中可得到各成分的保留时间、紫外光谱和分子量信息.通过比较合煎液和单煎液中各成分的保留时间及分子量信息可确定合煎液各峰的归属,最后比较了单煎液和合煎液的化学成分变化.结果表明,川芎和赤芍配伍后有一新峰产生,同时有两个成分含量发生变化.     

氢化物发生-原子荧光法测定中药(党参、黄芪、巴戟天)中的铅

应用AFS-2202a型双道原子荧光分光光度计和断续流动的氢化物发生技术,采用HNO₃-H₂O₂体系和高压釜消解中药样品测定了中药党参、黄芪、巴戟天中的铅。同时,研究了光电管负高压、灯电流、屏蔽气和载气流量、载流的选择,酸度的影响等。在选定实验条件下,铅的检出限为0.08 μg·L-1, 相对标准偏差为0.34%。该方法简便、快速、灵敏,对于实际中药样品的测定得到了满意的结果。     

Metrology in laboratory medicine – Reference measurement systems

 The medical laboratory must provide results of measurements that are comparable over space and time in order to aid medical diagnosis and therapy. Thus, metrological traceability, preferably to the SI, is necessary. The task is formidable due to the many disciplines involved, the high production rate, short request-to-report time, small sample volumes, microheterogeneity of many analytes, and complex matrices. The prerequisite reference measurement systems include definition of measurand, unit of measurement (when applicable), consecutive levels of measurement procedures and calibrators in a calibration hierarchy, international organizations, reference measurement laboratories, dedicated manufacturers, written standards and guides for the medical laboratory, production of reference materials, internal and external quality control schemes, and increasingly accreditation. The present availability of reference measurement procedures and primary calibrators is shown to be insufficient to obtain international comparability of all types of quantity in laboratory medicine. Received: 19 April 2000 / Accepted: 3 July 2000     

碳式碳酸钴分解产物的微量粉末X射线衍射分析

研究了碱式碳酸钴的氮气中的热分解反应,测定了其热重分析曲线,并用微量粉末X射线衍射法（样品重量约6mg)对其热分解的固体残留物进行了表征。实验结果表明：在339－394℃温度范围内生成尺寸16－18nm的Co3O4与CoO纳米晶混合物,在700℃的最终产物为尖晶石型Co2O4.计算的晶胸参数为：α=0.8084nm,V=0.5283nm^3,Z=8,Dcalc=6.073g/cm^3,与常规X射线衍射分析的结果相一致。     

镇咳祛痰合剂中微量、宏量元素测定及临床意义

采用火焰原子吸收分光光度法测定了镇咳祛痰合剂中钠、铁、锰、铜、锌、钙、镁、铬、镍九种微量、宏量元素的含量。结果表明,镇咳祛痰合剂中含有丰富的微量、宏量元素。为探讨中成药中微量、宏量元素与治疗哮喘和支气管炎疾病的关系提供了有用的依据。