用时域反射法对杞菊地黄丸干燥过程在线水分测定及干燥工艺优化

目的以杞菊地黄丸为研究对象,采用时域反射法实时测定浓缩丸干燥过程中水分含量及对干燥工艺进行参数优化。方法通过水分、温度以及时域反射计反射信号值之间的关系建立杞菊地黄丸干燥过程水分模型;以马钱苷和丹皮酚的干燥前后转移率为评价指标,结合干燥总用时、杞菊地黄丸的外观形态,综合考察药丸不同厚度(8、16、24 mm)、不同干燥温度(30、40、50、60、70、80、90℃)对干燥工艺的影响并对变温参数进行分析、验证。结果采用时域反射法测试杞菊地黄丸干燥过程水分模型为Y=0.305 X-34.772,r~2=0.999;X=X(T)-(0.768 9 T-24.824 7)(T≥30℃);优化后工艺为以60℃干燥至水分为13.8%后升温到80℃后继续干燥至7.80%后降温至60℃干燥到目标水分5.0%。结论时域反射法实时测试杞菊地黄丸干燥过程中水分的含量是可行的,该方法可尝试在中药浓缩丸干燥过程中水分监测推广应用,而且该方法可应用于中药浓缩丸干燥工艺优化,使干燥过程变得节能省时,使干燥产品质量可控。     

基于动态露点等温线法的莲子吸湿和解吸特性考察及模型确定＊

目的 考察莲子等温吸湿的吸附与解吸附特性，明确其等温吸湿和解吸规律，以更好地指导莲子的干燥加工和包装储藏，为防止莲子吸水过多而霉变提供数据支持。方法 在25℃条件下，采用基于动态水分吸附法的AQUALAB VSA等温吸湿曲线测定仪记录莲子及其粉末对水分的等温吸附和解吸附曲线，将所得数据采用8种常用模型拟合，引入相关系数（R²）和赤池信息准则（AIC）评价各个模型的准确性和可靠性。结果 25℃时，莲子药材及粉末的吸附和解吸附曲线趋势基本相同，Peleg模型为描述莲子吸附和解吸附特性的最佳模型。结论 通过对莲子等温吸附与解吸附曲线的考察，可以更好地了解中药材吸附与解吸附特性和规律，对指导中药材的合理加工、包装和储藏，保证药材质量和安全具有重要意义。     

Determination of moisture,total lipid,and bound lipid contents in oats using low-field nuclear magnetic resonance

In this study, we aimed to establish a novel method for determining moisture and lipid contents in oats using low-field nuclear magnetic resonance (LF-NMR). The applicabilities of the internal and external standard methods for determining oat moisture were compared. To determine oat lipids, calibration curves were established using the external standard method, and then the LF-NMR method and the conventional method were compared. The independent peaks of T₂₁ (0.01–3.0 ms) and T₂₂ (9.01–410.27 ms) in the T₂ spectral curves of oat flour represented water and lipid, respectively. Analysis of moisture content with the internal standard method was more accurate than with the external standard method, which uses 3 % MnCl₂•4H₂O as a standard. The area of T₂₁ peak and T₂₂ peak has a good linear correlation with the mass of water weight and lipid weight, respectively. The results of the LF-NMR method were consistent with the results of the oven method (for moisture content) and the Bligh method (for total lipid content). Moreover, the endosperm was found to contain 0.58–1.36 % of the bound lipid, which was slightly lower than the value for the oat bran.     

Efficiency of Twin-Screw Extrusion of Biodegradable Poly (Butylene Succinate)-Wheat Bran Blend

Unmodified poly (butylene succinate) (PBS) is characterized by very good processability; however, after the incorporation of various fillers of plant origin, its processing becomes much more complicated and its properties are significantly affected. Detailed studies of the processing aspects of PBS/wheat bran (WB) biocomposition are lacking, despite the addition of WB having a significant impact on both the production efficiency and the properties of end products. This research paper presents test results of the co-rotating twin-screw extrusion processing of a biodegradable polymer blend, the matrix of which was PBS, with WB as the filler. In undertaking this task, we examined the impact of extruder screw rotational speed and WB content on the characteristics of extrusion processing, as well as on certain thermal, physical, structural and processing properties of the obtained blend. The WB introduced to the blend was in the form of a selected fraction with particles smaller than 0.2 mm. The measurements were conducted using the Design of Experiment (DOE) methods, which enabled establishing the studied relationships in the form of polynomials and response surfaces. The determined extrusion process characteristics covered the impact of screw rotational speed and WB content on the mass flow rate of the processed blend and its pressure, the screw drive torque and specific energy consumption. The studies of the obtained polymer blend included determining the impact of the aforementioned variable factors on the melt flow rate (MFR) index, chemical structure (FTIR), thermal properties (differential scanning calorimetry (DSC), thermogravimetry (TG), derivative thermogravimetry (DTG)), p-v-T relationships, microstructure, density and moisture absorbance. Analysis of variance (ANOVA) was used to assess the effect of individual variable factors. The results of this work are presented, inter alia, using Pareto charts of standardized effects, which illustrate the influence of individual terms of the determined regression equations on the studied quantity.     

A comparison of five heat and moisture exchangers

Five heat and moisture exchangers were investigated to compare their efficiency of humidification, their ability to filter bacterial spores and their various physical properties. The results are presented and the various mechanisms of heat and moisture exchange are reviewed. The Pall Ultipor BB50, because of its hydrophobic properties, has a slightly different action from heat and moisture exchangers already in use, The place of the Pall Ultipor BB50 in clinical practice is discussed.     

Humidification devices

Humidification is concerned with the addition of water vapour to a gas and can be measured as either absolute or relative. Adequate humidification is a vital consideration in anaesthesia given that the anatomical source of natural gas humidification (the nasopharynx) is generally bypassed, which can lead to complications including hypothermia, thickening of respiratory secretions, mucus plugging and airway keratinization. Humidification may be passive or active. Equipment involved in passive humidification includes HME filters, soda lime and cold water baths, with these devices able to achieve varying efficiencies without extrinsic energy input. Active humidification devices (including hot water baths) are capable of delivering a higher relative humidity but are associated with higher cost and potential hazards. While not strictly classed as true humidification devices, nebulizers are considered in this article as they add water droplets into a gas flow using a Venturi system, spinning discs or ultrasound vibration technology.     

Mould-specific immunoglobulin G antibodies in students from moisture- and mould-damaged schools: A 3-year follow-up study

Immunoglobulin G (IgG) antibodies to moulds have been used as biomarkers of mould exposure, though their role reflecting exposure is not confirmed. The purpose of the present study was to evaluate the changes in mould-specific IgG antibodies in children during a 3-year follow-up in relation to changes in exposure, and to allergic and respiratory morbidity. In 1996, 212 primary school students with asthma, wheezing or prolonged cough participated in a clinical study, including clinical examination, skin-prick tests to 12 moulds and mould-specific IgG determinations to 24 moulds. In 1999, 144 students of the same cohort participated in an identical follow-up study; among them, mould-specific IgG was measured in 121 students. No association was found between IgG antibodies to moulds and exposure to moisture or moulds in schools. Likewise, changes in mould-specific antibodies were only weakly associated with changes in exposure. Mould-specific IgG antibodies had no significant association with asthma, wheezing or cough episodes. IgG antibodies to moulds seem to be poor markers of exposure among children exposed to moisture or moulds at school.     

朝鲜龙胆的生药学研究

目的 对中药朝鲜龙胆进行生药学研究,为其品质评价提供理论依据.方法 依据《中华人民共和国药典》中龙胆的研究方法对朝鲜龙胆进行性状鉴定、显微鉴定;同时测定其水分、灰分、浸出物;采用高效液相色谱法对其主要化学成分龙胆苦苷进行含量测定.结果 2个不同产区的朝鲜龙胆根中含水量分别为6.50%及6.42%;水溶性浸出物的含量分别为53.43%及40.84%;灰分含量分别为3.55%及4.10%;龙胆苦苷的含量分别为4.20%及5.40%.结论 朝鲜龙胆中龙胆苦苷的含量较高,水溶性浸出物的量亦较高,可作为龙胆新资源开发利用.     

基于质量综合评价的积雪草干燥方法筛选研究

目的探讨不同干燥方式对药材质量的影响,筛选积雪草适宜干燥方法。方法分别采用热风干燥、晒干、晒半干后热风干燥、阴干、微波以及真空干燥对积雪草全草鲜品进行干燥加工,并测定干燥时间和折干率;参考药典方法对积雪草药材性状特征、鉴别、检查、浸出物含量进行分析;采用HPLC法测定样品中积雪草苷、羟基积雪草苷、积雪草酸、羟基积雪草酸、山柰酚-3-O-芸香糖苷、山柰酚和槲皮素的含量;并采用加权评分法进行多指标综合评价排序。结果不同干燥方法耗时差异大,其中晒干、阴干和50℃真空干燥超过100 h,微波干燥低至1.5 h;折干率均值为24.83%;不同干燥方法对药材性状影响主要反映在色泽和气味,其中50～70℃热风干燥色泽较佳,为浅绿色,80、85℃热风干燥和微波干燥气味也发生了显著变化;水分和灰分含量虽有一定差异,但均符合药典标准;干燥方法对浸出物也有一定影响,晒干方式的浸出物含量达到最大,为45.70%,阴干方式的浸出物含量最小,为29.67%;HPLC法测定的7个有效成分含量总和最高的是较为温和的干燥方式阴干,为83.032 mg/g,最低的为75℃热风干燥,为40.982 mg/g;羟基积雪草苷和积雪草苷总和含量最高的为80℃热风干燥,最低的为75℃热风干燥;加权评分排在前3位的分别为70℃热风干燥、晒半干后50℃热风干燥、50℃热风干燥,85℃热风干燥排在末位。结论积雪草产地的适宜干燥方法为70℃热风干燥。