自动电位滴定仪在氨基酸测定中的应用

用自动电位滴定仪能对大多数氨基酸进行测定,经与常用的非水滴定、碘量法和碱滴定法比较,具有简便易行、准确、灵敏度高、相对误差小、用量少和快速等优点.     

哌仑西平的示波极谱滴定

过量四苯硼钠(1)标准溶液加到含样品的醋酸盐缓冲液(pH 5.3)中定量地沉淀盐酸哌仑西平,过量的1用 Tl_2SO_4滴定。本法准确、快速、简单。平均回收率为99.71%,变异系数为0.38%。     

Limiting Solubilities and lonization Constants of Sparingly Soluble Compounds: Determination from Aqueous Potentiometric Titration Data Only

A new method is described for the concomitant determination of limiting solubilities and ionization constants of sparingly soluble compounds, i.e., drugs. Aqueous potentiometric titration data were recorded both before and after precipitation of the compound and subjected to computer-assisted analysis. Limiting solubilities and ionization constants were obtained for nucleoside transport inhibitors, viz., dilazep, soluflazine, and hexobendine. The method was validated by comparison of titration results for known antidepressants with data from the literature. The procedure was found to be rapid and reliable for compounds with limiting solubilities as low as 30 µM, and it circumvents problems of direct methods for measuring limiting solubilities.     

膦甲酸钠及其制剂的含量测定法

研究了非水溶液滴定法测定膦甲酸钠原料药含量和分光光度法测定膦甲酸钠制剂(注射液和软膏)含量的条件,所得膦甲酸钠原料药、注射液和软膏的平均回收率分别为99.86±0.38％、99.98±0.50％和99.35±0.55％。     

新型液压自控牙用树脂聚合器研制与应用

目的：研制新型液压自控牙用树脂聚合器。方法：树脂修复体置于密闭聚合器中，旋紧其盖子使压力升至0.1MPa，然后自动电热加温，在聚合器内的水温升高的同时其压力亦在升高，水温每升高10℃，压力升高0.07-0.08MPa，当水温升至120℃时，压力升高至0.4-0.6MPa，维持3-10min，自动断水、排水，牙用树脂修复体聚合完成。结果：对常规装盒充填（无需机械夹紧），直接石膏包埋，灌注成形，涂塑成形塑料基托，硬质树脂制作间接贴面、嵌体、全冠、桥体以及硅橡胶制作义龈，可见光固化复合树脂二期处理等在压力水浴中进行快速热处理。结论：该聚合器采用直接液压，无需配用空压机加压，使用方便，可快速完成高质量塑料基托或硬质树脂等修复体，为口腔修复学增添一种新工艺和设备。     

Quantitative ultrasound imaging at the calcaneus using an automatic region of interest

A new approach to measuring bone properties at the calcaneus using ultrasound parametric imaging has recently emerged. However, an additional source of observer-related error is the substantial regional variations in the pattern of ultrasound parameters. The contribution of intra-observer and inter-observer variability to the coefficient of variation can be eliminated using an algorithm which selects the region of interest (ROI) completely automatically. The objective of the present study was the clinical assessment of an automatic ROI for both broadband ultrasonic attenuation (BUA) and speed of sound (SOS) measurement using ultrasound parametric imaging. The automatic ROI was defined as the circular region of lowest attenuation in the posterior tuberosity of the calcaneus. We have tested this algorithm using clinical images of the calcaneus from 265 women. Mean coefficients of variation were 1.6% (95% confidence interval 1.4%–1.9%) and 0.26% (95% confidence interval 0.23%–0.32%) for BUA and SOS respectively (standardized CV was 2.1% for BUA and 2.6% for SOS). Z-scores in an osteoporotic group were –0.61 and –0.52 for BUA and SOS respectively. In healthy women, the age-related decline was –0.50 dB/ MHz per year (0.7%/year) for BUA and –1.2 m/s per year (0.08%/year) for SOS. In the subgroup of healthy postmenopausal women, using stepwise multiple regression, we found that BUA was predicted best by years since menopause (YSM) and weight, with overall modelr ²=0.28; SOS was predicted best by YSM only (r ²=0.21). Neither the range of biological variation of ultrasound parameters nor the clinical value were affected by the choice of the region of lowest attenuation for measurement. The automatic procedure was totally independent of operator interaction, therefore excluding loss of precision due to intra- or inter-observer variability. The results showed the high precision and robustness of the procedure. These factors make this approach viable for routine clinical use.     

测定羰基化合物阶自动电位滴定法

本文介绍了自动电位滴定法测定羰基化合物的具体方法及其依据。实验结果证明该方法简便可行。     

Postcibal secretory and symptomatic responses to increased intragastric pressure

Abstract The mechanical and secretory factors in the stomach that may be implicated in the production of symptoms are still poorly understood. To determine whether symptoms in response to postcibal gastric distention are associated with increased acid secretion, the relationship between symptoms, acid secretion and intragastric pressure in healthy subjects was investigated. Perception (by a 0–6 score questionnaire) and the gastric secretory response to a glucose test meal (by intragastric titration) was quantified either at low (2 mmHg) or at high (8 mmHg) intragastric pressure levels, maintained by feedback regulation of the air volume within a gastric bag using an electronic barostat. Low intragastric pressure produced a small gastric expansion (87 ± 26 ml; mean ± SE) that was largely unperceived (score 0.7 ± 0.5). High intragastric pressure did not increase acid secretion (15 ± 3 mEq h^-1 vs 16 ± 3 mEq h^-1 at low pressure), but produced symptomatic perception (score 2.5 ± 0.7) related to a marked gastric expansion (521 ± 92 ml; P < 0.05 vs low pressure for both). It was concluded that postcibal gastric hypertension induces symptoms without affecting the gastric acid secretory response to the meal.     

Use of a personal computer for fast acquisition of cardiovascular data over an extended period

This paper describes data collection during open chest cardiovascular research based on an IBM compatible personal computer. Data from eight analogue data channels are collected at a rate of 500 Hz per channel for a period of more than 40 sec per run. General analysis functions include the integration of the data obtained from any channel as well as an exponential curve fitting routine. Special functions are available for the calculation of cardiac parameters. This includes the automatic determination of end-diastole and end-systole, as well as maximum and minimum values of all curves for both the systolic and diastolic phases of contraction.