Preparation of CeO_2 Nanoparticles and Its Application to Ion-selective Electrodes Based on Acetyl Cellulose

CeO2 nanoparticles with an average diameter of about 30 nm were prepared by sol-gel method at lower temperature. The gel, transformed from the aqueous solution of metal nitrate and citric acid, can be combusted completely at lower temperature. The redox behavior and the crystallization process of the dried gel were studied by thermogravimetric analysis and infrared spectroscopy. The synthesized powders were characterized by X-ray powder diffraction and transmission electron microscopy. In addition, rare earth elements ion-selective electrodes based on acetyl cellulose were prepared using ultra fine cerium oxide powders.

1例假性低钠血症的实验室分析

目的通过对1例低钠血症的实验室分析加强临床对假性低钠血症的认识。方法结合患者的疾病史,实验室检查结果,分析方法学检测原理以及更换方法学检测对造成患者低钠血症的原因进行分析。结果患者高蛋白血症干扰间接离子选择电极法对血钠的检测,造成血钠结果假性偏低。选用直接法的血气分析后血钠正常。结论高蛋白血症人群使用全自动生化分析仪检测血钠结果会造成假性偏低,可更换直接法检测,以免造成误诊。

采用离子选择性电极间接法检测血浆钾离子正常参考区间的建立与评价

目的建立惠州地区人群采用离子选择性电极间接法检测肝素钠抗凝血浆钾离子的正常参考区间及评价其必要性。方法用离子选择性电极间接法检测惠州地区1710例不同性别、年龄正常人群的肝素钠抗凝血浆钾离子浓度,用统计学方法分析制定正常参考区间;并用离子选择性电极间接法同比检测比较不同水平钾离子浓度的肝素钠抗凝血浆和血清两种标本类型,分析两者之间的差异。结果正常人群不同性别组间差异无统计学意义(P=0.743),成年组与未成年组和老年组相比差异均有统计学意义(P=0.004,0.003),成年组血浆钾离子平均浓度(3.69±0.28)mmol/L,未成年组和老年组合并血浆钾离子平均浓度(3.76±0.36)mmol/L,肝素钠抗凝血浆与血清两种标本类型在高中低三种水平检测中,差异均有统计学意义(均P=0.000)。结论本研究对惠州地区正常人群采用离子选择性电极间接法检测肝素钠抗凝血浆钾离子建立了正常参考区间,为临床准确诊治疾病提供了科学依据,同时为相关实验室制定正常参考区间提供参考数据。

基于电渣熔铸曲轴的钢水液位检测

基于电渣熔铸曲轴的自耗电极为规则圆柱体,根据测重法工作原理设计了一套微机控制检测系统,实现了电渣熔铸金属液面的间接自动检测。实验结果表明,该系统克服了传统传感器检测钢水液位影响因素多的缺陷,其检测精度高,可达毫米级,抗干扰性能强。

重度脂浊对间接离子选择电极法测定血清钠钾氯的干扰

目的:研究重度脂浊对间接离子选择电极法测定血清钠钾氯的干扰。方法:按照NCCLS推荐的EP7-A2和EP9-A2方案,选取温州医科大学附属第二医院40份无脂浊住院患者血清样本,分别采用间接离子选择电极法(西门子ADVIA 2400全自动生化分析仪)和直接离子选择电极法(强生VITROS 5600干化学分析仪)测定血清钠钾氯;再选取40份不同脂浊指数住院患者血清样本,分别用这2种方法测定血清钠钾氯;分别留取高、中、低不同浓度水平的血清钠钾氯患者样本设计体外干扰试验。结果:2种方法检测无脂浊血清的钠钾氯结果差异无统计学意义(P>0.05);直接法测定的脂浊血清钠、钾和氯结果明显高于间接法(P<0.05);体外干扰试验显示,甘油三酯浓度>35.3 mmol/L,脂浊指数>965时,间接法测定的血清钠水平位于113 mmol/L时存在明显负干扰(偏移>-2%);甘油三酯浓度>28.4 mmol/L,脂浊指数>710时,间接法测定的血清钾水平位于5.8 mmol/L时存在明显负干扰(偏移>-3%);甘油三酯浓度>20 mmol/L,脂浊指数>615时,间接法测定的血清氯水平位于79.6 mmol/L时存在明显负干扰(偏移>-2.5%)。结论:脂浊对间接离子选择电极法测定血清钠钾氯均存在负干扰,重度脂浊血清的钠钾氯检测以直接法的检测结果为准,也可以使用高速离心去除脂质后,再采用间接法测定。

Dimension AR全自动生化分析仪CO_2电极测血清总CO_2的应用及评价

目的:探讨Dimension AR全自动生化分析仪CO2电极测血清总CO2(TCO2)的应用及评价。方法:用Dimension AR全自动生化分析仪CO2电极检测血清TCO2。结果:用Dimension AR全自动生化分析仪CO2电极检测血清TCO2线性范围4.0mmol/L^48.0mmol/L;平均回收率99.6%;批内CV:低TCO2含量标本为1.61%,高TCO2含量标本为2.42%;批间CV:低值标本为3.38%,高值标本4.01%;与CO2酶法比较,r=0.9997,t=1.262,P>0.05;当TBIL<448.0umol/L、TG<23.8umol/L、HB<5g/L时,对测定结果无影响。结论:用Dimension AR全自动生化分析仪CO2电极检测血清TCO2准确、快速、稳定,具有很好的临床应用价值。

Kinetic Characteristics of Nitrate Uptake by Wheat and Rape and Their Determination

15-day old seedlings of wheat and rape were grown in a series of solutions with different concentrations of KNO3 for a definite period of time. The changes in NO3- concentration of the solutions were determined by the double ion-selective electrode method, and then the amount of NO3- taken up by the plants was estimated and values of Km and Imax of the Michealis-Menten equation were calculated. Results show that both the method and conditions of determination affected the values of Km and Imax. For example, the Km value was appreciably reduced when the volume of culture solution was increased or when the duration of nutrient uptake was shortened; the Km value obtained with short-term depletion method was higher than that obtained with long-term one. Similar Variations were found for the values of Imax. There was a considerable difference in the characteristics of uptake kinetics between wheat and rape when determined under the same conditions of determination. The isotherm of NO3- uptake by wheat could be separated into saturated and unsaturated parts, and when the concentration of NO3- exceeded 180 uuuuuuuuuuuuM, the relationship between the rate of NO3- uptake and NO3- concentration tended to be linear. However, the isotherm of NO3- uptake by rape was found to fit the Michealis-Menten equation and no linear relationship could be found.

高血脂对间接离子选择电极法检测电解质的影响

目的了解重度脂血对间接离子选择电极法测定血清电解质K^+、Na^+、Cl^-的影响。方法取血脂正常、轻中度血脂升高和重度血脂升高血清标本,各20份,分别在日立7600全自动生化分析仪和罗氏cobas b 123血气分析仪检测K^+、Na^+、Cl^-,对结果进行比较分析。结果对于血脂正常和轻、中度血脂升高的标本,日立7600全自动生化分析仪和罗氏cobas b 123血气分析仪检测的结果比较,差异无统计学意义(P>0.05);重度脂血标本日立7600全自动生化分析仪的检测结果低于罗氏cobas b 123血气分析仪的检测结果,差异有统计学意义(P<0.05)。结论对于重度脂血标本,直接离子选择电极法检测K^+、Na^+、Cl^-的结果更为真实可靠。

血清钾、钠离子选择性电极间接法与酶法测定的相关性分析

目的:对钾、钠离子选择性电极间接法测定与酶法测定的相关性进行比较,以确定离子选择性电极间接法与酶法的相关性。方法:通过对50例正常体检人群的血清钾、钠离子分别用离子选择性电极间接法和酶法同时分别测定。结果:离子选择性电极间接法和酶法相比,离子选择性电极间接法比酶法结果略高,但二者具有良好的相关性,与文献相符。结论:离子选择性电极间接法与酶法结果具有良好的相关性(P>0.05)。离子选择性电极间接法测定标准差比酶法标准差低,具有更好的精密度。

多发性骨髓瘤相关假性低钠血症致医源性高钠血症1例并回顾性分析

患者男,55岁,以"乏力、纳差半年余,发现肌酐升高1周"于2024年2月16日就诊于北京协和医院。综合临床表现及检验检查结果诊断为多发性骨髓瘤,我院就诊期间患者持续"低钠血症"(间接离子选择电极法测得Na 124~136 mmol/L),结合患者临床症状及血清渗透压结果(327 mOsm/kg H2O)考虑为高球蛋白血症导致假性低钠血症,未予干预,后续外院治疗期间因未识别出假性低钠血症而予高张盐水补液导致严重医源性高钠血症。建议对于各类原因导致的血清固相比例高于正常的患者,采用间接离子选择电极法测定血清钠极易出现假性偏低,可用直接离子选择电极法复测血钠以判断是否为真性低钠,避免为患者带来医源性损伤。

STUDIES ON RESPONSE CHARACTERISTICS OF DRUG ISE'S (Ⅶ)——PERFORMANCE AND THEORETICAL TREATMENT OF MICROCELLS CONNECTED IN SERIES

A new type of MCCS (microcells connected in series) has been constructed and its performances investigated. It has been applied to the determination of streptomycin. The sensitivity and accuracy have been increased significantly. A theoretical model for the error of determination using the MCCS has been suggested and proved experimentally using the Monte Carlo method, and the error model proposed in Ref. [1] revised.