单核细胞热原检测法的设计与应用要点分析

热原检测技术是保证药品安全性的一项关键技术。随着各类新型生物技术药品的发展,家兔热原检查法及细菌内毒素检查法作为传统热原检测方法控制此类产品安全性的能力正面临严峻挑战,研究建立单核细胞热原检测法替代上述传统热原检测方法是该领域的整体发展趋势,《中国药典》四部(2020版)将收录该方法。本文主要就单核细胞热原检测法的选择、设计、材料、步骤、试验有效性及方法变异等方面对该方法的设计与应用要点进行分析,以期为准确应用该方法控制相关产品的质量提供参考。     

发酵工艺中热原管理及改善措施分析

在应用临床药品的过程中,患者可能会发生各种各样的不良反应,作为较为严重的一种不良反应,热原的产生和许多因素有关,为了使药品质量得到有效控制,必须要全面把控药品生产的每个环节,对热原加强控制。如果热原没有控制好,会严重影响药品的质量,所以控制热原质量成为当前重点研究的问题。通过加强药品生产过程中热原管理,制定改善措施,可以有效控制药品中的热原水平,让药品更安全、更具有市场竞争力。首先对药品生产热原的研究现状及性质进行了分析,讨论了热原的检测方法以及热原管理的要点,最后提出了药品生产热原的改善措施。     

氨苄西林钠细菌内毒素法代替热原检查法的建立及两种方法的对照

探讨了氨苄西林钠(无菌粉)用细菌内毒素法代替热原检查法的建立,以提高产品热原检测效率,同时对两种方法进行了对照实验.     

黄芪注射液中细菌内毒素与热原相关性研究及限度的确定

建立了黄芪注射液细菌内毒素与热原之间的关系,并确定其细菌内毒素的限度。用稀释16倍的黄芪注射液配成含不同浓度梯度的细菌内毒素系列样品,分别用动态浊度法和家兔法测定细菌内毒素和家兔最大升温值。结果表明,细菌内毒素方法建立中,黄芪注射液在稀释8～64倍后测定无干扰;细菌内毒素浓度与家兔体温升高值有相关性,回归方程为Y=0.448+e3.221 X(r2=0.997);进一步考虑热原检查法的偏差,黄芪注射液的细菌内毒素限度应不超过2.31EU/mL。因此,采用动态浊度法可对黄芪注射液中细菌内毒素进行测定并建立可靠的限度标准。对中药无菌制剂采用细菌内毒素测定法提供一种研究思路,同时为快速反映中药无菌制剂的热原情况提供一种有效的转换方法,尤其有利于中药无菌制剂中间体热原的控制。     

传递手工的体温

今年暑假注定难忘。我有幸入围“中国‘手’创——手工益设计大赛”采风夏令营,并和30几名来自全国各地的队友参加了大赛组织的夏令营采风活动,对一些传统手工艺的现状有了切身的体验,同时也对自己所学专业有了全新的认识。     

热老化箱性能对橡胶试验结果的影响

选取2种典型的老化箱,分析了老化箱性能对热氧老化、恒压和耐液体试验结果的影响。结果表明,普通型老化箱对热老化试验结果有较大的影响,换气式老化箱可严格控制各项试验条件,对结果的影响较小;老化箱对高温恒压和耐液体试验结果的影响几乎可忽略。     

多功能体温监测胃管的制备

采用聚氨酯、聚氯乙烯、温度感应线等制备了可连续测定病人温度且有较多功能的监测胃管。经检测,所制监测胃管的各项技术指标符合要求,不仅能满足一般胃管的功能,而且可持续、准确检测体温,特别适用于重症病人的监护。     

一种螺环原碳酸酯膨胀单体的合成及其与环氧树脂热固化

经两步法合成了一种螺环原碳酸酯类膨胀单体,该单体在固化剂三氟化硼乙胺催化作用下,能进行阳离子双开环聚合反应,并讨论了该单体聚合反应机理。采用差示扫描量热(DSC)跟踪环氧树脂及其被膨胀单体改性后的固化反应过程,发现纯环氧树脂存在2个固化反应放热峰,而改性树脂仅有一个反应放热峰。结果表明:膨胀单体和环氧树脂进行了开环共聚反应,膨胀单体的加入能提高环氧基团的转化率。     

改良热固法制备白蛋白微球的工艺研究

采用改良的热固化法制备了白蛋白微球,研究了乳化时搅拌速度和混合乳化剂对微球粒径大小的影响。结果表明较适宜的乳化搅拌速度为3500r／min,所制得白蛋白微球呈球形,表面光滑,粒径范围小;采用Span-80和Tween-80混合乳化剂时制备得到的白蛋白微球,比用单一的乳化剂制得的微球效果好,白蛋白微球呈球形,粒度在0．2μm到几个微米之间。     

胶料热老化性能试验

对以天然橡胶和顺丁橡胶并用的胶料,在无防老剂和有防老剂状态下分别进行热老化和热氧老化对比试验,试验表明,试片在无氧热老化条件下胶料的性能下降很少,而且经较长时间硫化的试片对胶料热氧老化性能略有提高.配方中增用防老剂后,明显提高了胶料的耐热氧老化性能,特别是经较长时间硫化的试片热氧老化性能更进一步提高.     

Thermodynamic properties of normal butane at refrigeration temperatures

Presented in both English and SI units are tables of the thermodynamic properties of normal butane over the temperature range -22 to +122°F (-30 to +50°C). Values are tabulated of the volume, enthalpy, and entropy for the subcooled liquid, the saturated liquid and vapor and the superheated vapor in both unit systems. The data used to calculate these properties have been carefully evaluated and include very recent values of the low temperature heat capacity of the vapor. Two enthalpy-entropy charts (Mollier diagrams), one in each of the unit systems are presented. These are suitable for the design of machinery used in thermo-mechanical energy cycles such as the freezing and eutectic processes for treating sea water and waste water. The calculated thermodynamic properties are the only ones available for n-butane which cover the above complete temperature range.     

Interpretation of results of full notch creep test and comparison with notched pipe test

Abstract

An investigation of two tests commonly used to determine resistance to slow crack growth in PE pipes and materials is detailed, in order to gain a greater understanding of the mechanisms involved and to resolve differences in results observed. The full notch creep test (FNCT) is carried out on small notched bars machined from sheet or pipe loaded to create high constraint at the notch tip. The notched pipe test (NPT) is a pressure test on pipe containing external machined notches. In this test, it has been observed that the use of more flexible materials allows deformation in the crack tip region and contributes to slow crack growth resistance via crack tip blunting. Good pipe performance can be achieved by selecting materials with high inherent slow crack growth resistance or by combining inherent resistance with blunting mechanisms promoted by a lower density material. It is concluded that the FNCT test, while useful for an indication of inherent slow crack growth resistance, cannot be used to predict pipe performance for a range of materials, and therefore is unsuitable as a reference test for a pipe product specification. The NPT test remains the benchmark test for pipe performance and is referenced by many specifications.     

Variability of aflatoxin test results

Using 12 lb samples, 280 g subsamples, the Waltking method of analysis, and densitometric procedures, the sampling, subsampling, and analytical variances associated with aflatoxin test procedures were estimated. Regression analysis indicated that each of the above variance components is a function of the concentration of aflatoxin in the population being tested. Results, for the test procedures given above, showed that sampling constitutes the greatest single source of error, followed by subsampling and analysis. Functional relationships are presented to determine the sampling, subsampling, and analytical variance for any size sample, subsample, and number of analyses.     

Reproducibility of stress-cracking test results

The environmental stress crack resistance of polyethylene is measured most conveniently by the bent-strip method described in ASTM D-1693-70. The method has, however, suffered from poor reproducibility of test results. In this work we have carefully studied the effect of individual experimental variables that enter the test method. The effects considered are: the thermal history of test specimens; uncontrolled variations in the test procedures such as the sample holder width, the specimen thickness, and the stress relaxation occurring during the test; and the variability in the test results arising from the statistical nature of fracture process. It is concluded that each of the following four factors, when not properly controlled, could contribute an apparently random variation of a factor of two or more in the test results. These are (1) the aging of polyethylene specimens at room temperature, (2) the width of the specimen holder, (3) the dimensions of the tools employed for bending and transferring specimens, and (4) statistical fluctuations of the final results arising from the limited number of specimens tested and also from the stress relaxation occurring in the specimen during the test. By carefully controlling these and other variables, it should be possible to design a test procedure which is expected to yield results of a known precision and can serve even as a research tool.     

Material properties and fire test results

Five material properties commonly used to describe the fire behavior of solids were evaluated as sole explanatory variables for four small‐scale fire tests with pass/fail outcomes by using a physically based probabilistic (phlogistic) burning model. The phlogistic model describes the likelihood of passing vertical Bunsen burner tests and a regulatory heat release rate test reasonably well over a wide range of material properties, as deduced from the correlation coefficient and mean deviation of the predicted and measured values. Of the thermal, combustion, and fire properties examined, the best predictors of the likelihood of passing the fire tests of this study were the heat of combustion of the sample, the heat release capacity, and the heat release parameter. The relative merits and drawbacks of qualitative (threshold) and quantitative (probabilistic) approaches to predicting fire test results using thermal and combustion properties are discussed. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.     

Effect of elevated temperatures and cooling regimes on normal strength concrete

The compressive strength of normal strength concrete at elevated temperatures up to 700^°C and the effect of cooling regimes were investigated and compared in this study. Thus, two different mixture groups with initial strengths of 20 and 35 MPa were produced by using river sand, normal aggregate and portland cement. Thirteen different temperature values were chosen from 50 to 700^°C. The specimens were heated for 3 h at each temperature. After heating, concretes were cooled to room temperature either in water rapidly or in laboratory conditions gradually. The residual strengths were determined by an axial compressive strength test. Strength and unit weight losses were compared with the initial values. Throughout this study, ASTM and Turkish Standards were used. It was observed that concrete properties deteriorated with the heat; however, a small increase in strength was observed from 50 to 100^°C. Strength loss was more significant on the specimens rapidly cooled in water. Both concrete mixtures lost a significant part of their initial strength when the temperature reached 700^°C. Copyright © 2008 John Wiley & Sons, Ltd.     

Experimental results of a pull-out test performed with single- and multi-fiber samples

Widely-used methods for characterising the fibre/matrix interface in polymeric composites are the fragmentation test and the droplet test as a special kind of the single-fibre pull-out test. A severe disadvantage of these tests is that non-realistic model samples are investigated which contain only one fibre in the matrix. In order to obtain data about the effect of the different residual stress situations for fibres in such samples and in composites, pull-out tests of E-glass fibres in polystyrene and polycarbonate are performed using samples, where the investigated fibre is surrounded by 0 to 3 other near fibres. Neighbouring fibres can increase the pull-out forces by a factor of three and the interfacial toughness by a factor of four. This has to be taken into account, if the tests are performed not only for comparison reasons but for measuring interface properties.