红外分光光度法鉴别阿莫西林胶囊

【】 目的：建立阿莫西林胶囊的红外光谱鉴定法。方法：取胶囊内容物,以高纯度溴化钾压片,直接测定红外吸收光谱。结果：阿莫西林胶囊与阿莫西林对照品的红外光谱完全一致,并与《药品红外光谱集》中阿莫西林的标准光谱一致。结论：本方法专属性好,能快速、准确,可用于阿莫西林胶囊中阿莫西林成分的鉴别。     

Effect of cigarette smoking on the gastric mucosal blood volume index and hemoglobin oxygenation in man

The acute effect of cigarette smoking on the gastric mucosal blood volume index and the oxygen saturation of hemoglobin (SO₂) in the gastric mucosa was investigated in 12 young male volunteers using reflectance spectrophotometry during endoscopy. Six of these volunteers were habitual smokers who had smoked more than 20 cigarettes a day for more than five years. The others were non-habitual smokers who smoked less than 20 cigarettes a year. The indices of mucosal blood volume and the mucosal blood SO₂ level were calculated from the spectra obtained at the lesser curvature of the lower corpus of the stomach before and after cigarette smoking. The indices of mucosal blood volume and mucosal blood SO₂ decreased significantly after one to three puffs of cigarette smoking in all subjects as compared to the value before smoking, and the degree of decrease in these parameters was significantly greater in the non-habitual smokers than in the habitual smokers. These results suggest that only one to three puffs of cigarette smoking causes a decrease in the mucosal blood volume and the mucosal blood SO₂ which might be related to weakening of mucosal defensive factors. This work was supported by a grant from the Japan Tobacco Corporation.     

砷铈催化分光光度法测定尿碘的实验室内质量控制

目的建立砷铈催化分光光度法测定尿中碘的实验室内质量控制体系。方法通过试验确定砷铈催化分光光度法测定尿中碘方法的精密度、准确度和检出限,绘制碘测定的均数质量控制图。结果该方法的标准曲线范围碘质量浓度为0～300μg/L,标准曲线的相关系数｜r｜=0．9998,检出限3μg／L,加标回收率为92．4％～106．2％,相对标准偏差0．65％～1．43％。结论实验室内质量控制体系的建立,保证了砷铈催化分光光度法测定尿中碘的结果准确可靠。     

《中国药典》2015年版中纯化水硝酸盐检查商榷

目的：对《中国药典》2015年版二部纯化水中硝酸盐的检查方法提出意见建议。方法：按照标准考察了试剂“硫酸”对硝酸盐检查结果的影响,并首次建立了紫外-可见分光光度法作为硝酸盐检查的方法。结果：试剂“硫酸”的质量对硝酸盐比色法的检查影响很大,可采用紫外-可见分光光度法进一步测定。结论：紫外-可见分光光度法可作为《中国药典》纯化水中硝酸盐检查方法的重要补充。     

Color Aspect of Monolithic Zirconia Restorations: A Review of the Literature

Monolithic zirconia restoration is an acceptable treatment option in restorative dentistry and a developing trend in esthetic dentistry. Digital dentistry has simplified fabrication of monolithic zirconia restorations. Zirconia ceramic has introduced an opportunity to achieve both esthetic and mechanical requirements for restorations. This is rarely found for a ceramic in dentistry. Monolithic zirconia restorations represent an acceptable durability, comparable to metal‐ceramic restorations, while they are superior to metal‐ceramic restorations esthetically; however, difficulties to gain an optimal shade reproduction and a color match with monolithic zirconia restorations still remain. The color of these restorations may be influenced by manufacturing processes, laboratory procedures, and clinical factors. Manufacturing processes determine basic optical properties of zirconia ceramics. Different laboratory procedures may create optical changes in zirconia ceramics. Also clinical factors such as dental background, cement, and zirconia restoration features may affect the resulting color. This literature review aimed to discuss potent factors in the color of monolithic zirconia restorations. An electronic search of the PubMed/Google Scholar database was performed to find related English‐language articles published between January 1, 2000, and October 31, 2017. The key terms of background, cement, ceramic, color, esthetics, shade, spectrophotometry, thickness, translucency, and zirconia were used both individually and simultaneously. Also, a manual search was conducted, and five classic articles of color science were added. Thus 192 articles were included. In the last decade, shade reproduction of monolithic zirconia restorations has been highly regarded; however, further improvements are required in the manufacturing process to produce tooth‐like zirconia ceramics. An esthetic guideline named background‐cement‐ceramic color harmony was suggested in this study; however, more clinical practice guidelines should be established for monolithic zirconia restorations on esthetics, and therefore, more studies are required.     

Assessment of Color Stability of White Mineral Trioxide Aggregate Angelus and Bismuth Oxide in Contact with Tooth Structure

Introduction

Dental discoloration with use of materials containing bismuth oxide has been reported. It is postulated that the discoloration is a result of chemical interaction of bismuth oxide with dentin. The aim of the study was to analyze dental color alteration and the chemical interaction of bismuth oxide with the main components present in composite (methacrylate) and in dentin (collagen).

Methods

Fifty bovine teeth were prepared and filled with white mineral trioxide aggregate (MTA) Angelus, Portland cement (PC) with 20% zirconium oxide, or PC with 20% calcium tungstate and then sealed with composite. Triple antibiotic paste and unfilled samples were the positive and negative controls, respectively. The specimens were stored in separate flasks immersed in tap water at 37°C with ambient light blocked out. The color assessment was performed with a spectrophotometer at different intervals, namely before filling and 24 hours, 15 days, and 30 days after filling. The color change and the luminosity were calculated. The statistical analysis was performed by using nonparametric Kruskal-Wallis and Dunn tests (P < .05). The interaction of the bismuth oxide, zirconium oxide, and calcium tungstate with collagen and methacrylate was assessed by placing the materials in contact, followed by color assessment.

Results

The analysis of color change values showed that all the materials presented color alteration after the evaluated periods. Statistically higher luminosity was verified for PC/20% zirconium oxide in comparison with white MTA Angelus (P < .05). The teeth filled with white MTA Angelus demonstrated a grayish discoloration with evident dentin staining. Bismuth oxide exhibited a color change when in contact with collagen.

Conclusions

The color of white MTA Angelus was altered in contact with dental structures. Collagen, which is present in dentin matrix, reacted with bismuth oxide, resulting in a grayish discoloration. The use of an alternative radiopacifier to replace bismuth in white MTA is indicated.     

紫外分光光度法测定蜈蚣甘草散中重金属的含量

目的：测定蜈蚣甘草散中重金属的含量。方法：蜈蚣甘草散灰化后用硫化钠显色,用紫外分光光度法测定蜈蚣甘草散中重金属的含量。灰化温度550℃,时间2h;测定条件：pH3．0-3．5,波长202nm。结果：线性范围0-50μg,平均加样回收率为99．52％,RSD1．82％。结论：本方法可靠,稳定性、重现性好,可作为蜈蚣甘草散中重金属限量控制的方法。     

常润茶服用方法对蒽醌类物质溶出的影响及其通便作用的相关性研究

目的：以常润茶为例研究蒽醌类物质的加水量及浸泡次数等服用方法对有效成分溶出及通便作用的影响。方法：利用紫外分光光度法建立总蒽醌的含量测定方法,利用高效液相色谱法建立番泻苷A、番泻苷B、大黄酸的含量测定方法,考察不同浸泡次数、加水量下常润茶水浸液中有效物质的含量变化。利用洛哌丁胺复制便秘模型进行通便作用的验证并探究常润茶对肠动力及黏液分泌的影响,观察不同浸泡次数、加水量对小鼠小肠推进率、首粒排黑便时间、5 h黑便粒数、粪便含水量以及结肠胃动素(MTL)、促胃液素(GAS)、生长抑素(SS)、P物质(SP)的影响。结果：加水量与蒽醌类物质的溶出正相关,加水60～100倍蒽醌类物质溶出差异不大;浸泡1次可将大部分蒽醌类物质溶出,从第2次浸泡开始,总蒽醌、番泻苷A、番泻苷B、大黄酸的含量均明显减小。动物实验结果显示加水倍数为40倍、60倍、100倍时,常润茶均可有通便作用,未出现腹泻等不良反应,60倍、100倍水量通便作用显著。加水100倍,反复冲泡多次通便作用不优于浸泡1次。结论：本实验为产品的精准应用提供实验依据,对于规范蒽醌类产品具有积极意义。     

不同产地沙棘中总黄酮含量比较分析

目的 对不同产地沙棘总黄酮含量差异进行分析。方法 以异鼠李素为对照品,以AlC13为显色剂,采用可见-紫外分光光度法在430nm下进行测定。结果 异鼠李素在10．2～51．1μg/ml范围内呈现良好线性关系,相关系数为0．9996;平均回收率为96．81％,相对标准偏差为3．1％。结论 不同产地沙棘总黄酮含量存在差异。该方法简捷、准确。     

基于分光光度法测定血液中非那西丁与扑热息痛含量的肝脏储备功能评估

目的建立基于分光光度法测定非那西丁与扑热息痛含量的肝脏储备功能评估方法。方法筛选分光光度测定的显色体系,确定最大吸收波长,分析不同因素对显色体系的影响,优化非那西丁与扑热息痛水解的最佳条件,最后对技术体系进行应用性验证。结果建立了利用分光光度测定样品中非那西丁和扑热息痛含量的技术体系,即样品加入3 mol/L盐酸水解30 min,加入0.02%1,2-萘醌-4-磺酸钠、1%十六烷基三甲基溴化铵及2%Na OH(或3%Na2CO3)(比例为1∶6∶1∶2或3),分别于500 nm和570 nm下测定吸光值,计算各自浓度。该技术测定血浆样品中非那西丁与扑热息痛时的分辨率和重复性与高效液相色谱法相当。结论利用分光光度技术测定血液中非那西丁与扑热息痛含量,二者比值具有评估肝脏储备功能价值。