Evaluation of the epidermal refractive index measured by optical coherence tomography

BACKGROUND/AIMS: It has recently been proposed that the refractive index (RI) measured by means of optical coherence tomography (OCT) may be a valid measure for hydration of skin. In this pilot study, using OCT in vivo, we aimed to investigate the interday variability of RI measurements and acute changes of RI following the application of a moisturizer. METHODS: Twenty healthy Caucasian volunteers were investigated on their forearms using a commercially available OCT system (SkinDex 300, ISIS optronics GmbH, Mannheim, Germany) fitted with an integrated algorithm for the evaluation of the RI. The interday repeatability of the OCT method was determined performing symmetrical measurements on both forearms on day 1, 5, 9, and 13. In order to investigate the acute effect of a moisturizer on RI, OCT assessments were performed before and 10 min after the application of an aqueous lotion with a lipophilic phase. As a control, the contralateral site was investigated in the same way, except for the use of distilled water instead of the lotion. RESULTS: Assessments of interday variability revealed insignificant (P>0.05) variances between the four measurement times as expressed in very small repeatability coefficients (right arm: 0.039; left arm 0.053) and small coefficients of variance (right arm: 1.02%; left arm: 1.38%). With regard to the RIs measured over time, we could not observe significant (P>0.05) differences between the two symmetrical anatomic sites (mean+/-SD of RI: 1.3893+/-0.0142 (right arm); 1.3875+/-0.0192 (left arm)). The acute effect of the moisturizer was indicated by a significant decrease of the RI 5 min after the application of the lotion (1.399+/-0.01 vs. 1.387+/-0.02; difference between means: 0.012; P=0.033; 95% confidence interval: 0.001-0.0023). However the control site treated with distilled water did not show significant differences between the two measurement times (1.387+/-0.013 vs. 1.391+/-0.023; difference between means: -0.004; P=0.57; 95% confidence interval: -0.019-0.011). CONCLUSIONS: In this pilot study, we have demonstrated that RI evaluation via OCT is a promising technique that may be used for the assessment of skin hydration in vivo. However, the direct comparison of OCT with standard methods, ideally such as nuclear magnetic resonance spectroscopy, is necessary.     

胡萝卜脆片真空油炸脱水工艺的优化

研究了不同预处理条件及油炸温度、真空度、时间对胡萝卜脆片品质的影响.通过响应面分析可知:油炸温度、真空度及油炸时间显著地影响胡萝卜脆片中水分与脂肪质量分数、脆度,其最佳油炸工艺条件为温度100～110℃,真空度0.08～0.09MPa,时间15min.     

Moisture transport into chlorofluorocarbon-free metered dose inhalers

Moisture is known to affect the stability of some metered dose inhalers (MDIs). Hydrofluoroalkanes such as tetrafluoroethane (134a) and heptafluoropropane (227) are known to have higher affinity for moisture than the currently used chlorofluorocarbon propellents. An initial study was conducted to determine the water vapor transmission rates of various elastomers that may be used as gaskets in MDIs. A further study was conducted to measure the moisture ingress rates of various chlorofluorocarbon-free MDIs. The data indicate that moisture transport into chlorofluorocarbon-free MDIs is influenced by the elastomeric nature of the gaskets used and the type of hydrofluoroalkane formulation and storage conditions used.     

氧气湿化瓶消毒保存方法的改进

目的　探讨氧气湿化瓶最有效的消毒、保存方法 ,减少湿化瓶的污染。方法　设常规组、观察组氧气湿化瓶各 10 3件 ,常规组用 0 .1%消毒灵 (含有效氯 4 0 0mg/L)浸泡 30min ,取出用无菌蒸馏水均匀冲洗晾干后安装在氧气瓶上备用。观察组用 0 .1%消毒灵浸泡 30min ,再用 95 %的酒精干燥处理后安装在氧气瓶上备用。二组均在消毒处理后 1,3,5 ,7d分别采样培养 ,比较污染程度。结果　随着保存时间延长常规组污染率明显增加 ,观察组污染率明显低于常规组。常规组、观察组保存 7d的污染率分别是 5 2 .2 8%和 9.71% ,两组比较 ,有高度显著性差异(P <0 .0 1)。结论　氧气湿化瓶在常规消毒处理后加用 95 %的酒精进行干燥处理 ,能提高消毒效果 ,延长保存时间。     

纳米喷雾干燥技术用于生地黄低聚糖微粉的制备工艺研究

目的采用纳米喷雾干燥技术制备载药量高、收率高、吸湿性好的生地黄低聚糖微粉。方法采用B-90纳米喷雾干燥仪制备生地黄低聚糖微粉,采用单因素试验考察后,通过正交试验设计,以平均粒径、收率和吸湿率为评价指标,考察进风口温度、喷雾干燥效率和药液质量分数对制备工艺的影响并优选最佳制备工艺。结果正交试验结果得到最佳制备工艺条件:进风口温度为110℃、喷雾干燥效率为50%、药液质量分数为1.0%,最终得到了载药量为30%、收率为89%、吸湿性良好的生地黄低聚糖微粉,微粉形态稳定。结论采用纳米喷雾干燥技术制备生地黄低聚糖的工艺稳定可行,得到的微粉质量良好,优于传统的喷雾干燥。     

薄膜包衣在中药防潮中的应用

中药制剂易吸潮严重影响药品的稳定性。简要介绍了中药制剂吸湿性原理、薄膜包衣的优点及应用现状,重点从薄膜包衣的成膜原理、处方组成、影响包衣制剂的工艺参数等方面综述薄膜包衣在中药防潮中的应用。综合国内外薄膜包衣分析技术并探讨其在中药防潮分析上的应用。近几年,虽然薄膜包衣已广泛应用于药物制剂,但由于中药成分的复杂性,薄膜包衣在中药防潮方面的研究和应用还不够深入。随着对新型薄膜包衣材料及在线分析技术的研究,薄膜包衣在中药方面的应用将得到进一步的关注,并将在中药现代化发展进程中发挥较大的潜力。     

麝香不同成熟阶段化学成分变化规律

目的 探索不同成熟阶段麝香中化学成分变化规律.方法 通过"活麝取香"法采集不同成熟阶段麝香,测定含水量,并通过GC-MS分析其主要成分含量变化规律.结果 6月底麝香平均含水量为55.921％,高于10月底的36.029％(P＜0.05).从6月到8月和10月,麝香中成分种类呈先升后降的变化趋势.6月底麝香中检测到55种...     

Numerical Simulation of the Impact of Water Vapour and Moisture Blockers in Energy Diagnostics of Ventilated Partitions

Current trends towards saving energy and designing sustainable buildings result in most designers focusing on achieving the best thermal parameters, thereby neglecting a careful moisture analysis. Excessive moisture content in building partitions degrades the mechanical properties of materials, reduces thermal insulation properties (which leads to an increase in the demand for thermal energy) and worsens the microclimate in rooms. Modern digital solutions help create appropriate models of partitions that work for many years in good environmental conditions. According to the analysis of air parameters, 1 m³ of air at 20 °C contains approx. 17.3 g of water. When the temperature of the air reaches the dew point temperature, water vapour condenses. The dew point depends on air temperature and relative air humidity; for instance, at the same air temperature of 20 °C, the dew point temperature at 40% relative air humidity is 6 °C, whereas at 90% relative humidity, it is over 18 °C. This means that the higher the value of relative humidity in the room at a certain temperature, the lower the temperature that will cause condensation. The article presents a numerical analysis of the insulation work of flexible materials within the layers of ventilated partitions in an 8-year simulated period of varying environmental conditions. The aim of the article is to analyze different models and variants of ventilated partition operation with respect to the advisability of using a vapour barrier to avoid the problem of destruction of thermal insulation and finishing layers of a ventilated roof.     

Numerical Modeling of Chloride Transport in Concrete under Cyclic Exposure to Chloride

Concrete structures under cyclic exposure to chlorides entail a higher risk of embedded steel corrosion along with accelerated ionic ingress from the environment. This study proposes a coupled transport model considering moisture and chloride distribution in concrete to investigate the influence of a cyclic exposure condition on chloride penetration. In this model, pore size distribution to quantify the effective pore space for moisture and chloride mobilizations was determined to establish the governing equation for chloride transport through non-saturated concrete. From the simulation results, the rate of chloride penetration increases with decreasing ambient humidity levels due to the enhanced chloride convection. Finally, the coupled transport model was verified by comparing in-situ data, showing reasonable correlations with 0.83 and 0.93 of determinant coefficients for 22 and 44 years of exposure, respectively, while those obtained from LIFE 365 were much lower.     

一次性气管切开集痰保湿防护罩在气管切开术后患者气道湿化中的应用效果

目的 评价一次性气管切开集痰保湿防护罩在气管切开术后非机械通气患者气道湿化中的应用效果.方法 选取气管切开术后非机械通气患者48例,随机将其分入传统组(n=16)、实验组(n=16)和对照组(n=16).传统组采用2层湿纱布覆盖气管切开导管口进行湿化,实验组使用防护罩湿化,对照组使用人工鼻湿化.比较3组患者呼吸功能、气...