合欢皮标准汤剂的HPLC指纹图谱研究

为全面反映合欢皮标准汤剂多种组分的面貌,明确合欢皮标准汤剂的HPLC指纹图谱,对15批合欢皮标准汤剂进行了HPLC指纹图谱测定及相似度评价。采用HPLC方法,色谱柱为Waters Symmetry shield RP C_(18)柱(4.6 mm×250 mm,5μm),以乙腈-0.04%磷酸溶液为流动相进行梯度洗脱,检测波长为210 nm,流速为1 mL/min,柱温为25℃,对照指纹图谱对合欢皮标准汤剂进行相似度评价及聚类分析。结果表明,15批合欢皮标准汤剂指纹图谱中呈现10个共有峰,相似度为0.967～0.998,表明合欢皮标准汤剂具有良好的一致性;此外,在10个共有峰中指认出(-)-丁香树脂酚-4-O-β-D-呋喃芹糖基-(1→2)-β-D-吡喃葡萄糖苷、异槲皮苷2个化学成分。因此,合欢皮标准汤剂指纹图谱反映了合欢皮标准汤剂的多组分面貌,具有良好的可行性,可为合欢皮配方颗粒的多组分质量控制提供参考。     

知母饮片、水煎剂和配方颗粒HPLC指纹图谱相关性研究

为了考察知母饮片、水煎剂和配方颗粒之间化学成分的差异,采用HPLC法对三者的指纹图谱进行了相关性研究。选用Inertsil ODS-3柱(250mm×4.6mm,5μm),以乙腈为流动相A,1%醋酸为流动相B进行梯度洗脱,流速为1mL/min,柱温为30℃,检测波长为265nm,采集时间为100min,分别建立10批知母饮片、10批知母水煎剂与10批知母配方颗粒的指纹图谱。结果显示,10批知母配方颗粒HPLC指纹图谱的9个指纹峰均可在饮片中得到追踪,相似度均大于0.95,从9个共有峰中指认出芒果苷,知母饮片、水煎剂和配方颗粒的主要化学成分基本相同。本研究所建立的指纹图谱方法重复性、稳定性好,可用于饮片、配方颗粒生产过程中的质量控制。     

葛根水煎剂和配方颗粒HPLC指纹图谱相关性研究

为了能全面准确地反映葛根配方颗粒和水煎剂成分的一致性和葛根配方颗粒替代传统饮片的可行性,对葛根配方颗粒和水煎剂的特征图谱进行了相关性研究。采用华谱XAqua C18(250mm×4.6mm,5μm)色谱柱,以甲醇-0.1%冰醋酸水溶液为流动相进行梯度洗脱,检测波长为250nm,流速为1.0mL/min,柱温为25℃,采集时间为41min,分别建立10批葛根水煎剂和10批葛根配方颗粒的特征图谱。结果表明,10批葛根配方颗粒HPLC特征图谱的8个特征峰均可在水煎剂中得到追踪,相似度均大于0.99,并从8个共有峰中指认出葛根素。葛根水煎剂和配方颗粒的主要化学成分基本相同,且共有成分含量比例相近,为中药配方颗粒替代传统饮片的可行性以及临床研究提供了重要依据。     

山楂标准汤剂的HPLC特征图谱研究

为了进一步研究山楂配方颗粒的质量控制方法,以山楂标准汤剂为研究对象,采用高效液相色谱仪与GL science C_(18)(4.6 mm×250 mm,5.0μm)色谱柱,以乙腈-0.4%磷酸为流动相,柱温为30℃,流速为1.0 mL/min,检测波长为254 nm,应用特征图谱技术以及中药指纹图谱相似度评价软件提取山楂标准汤剂特征图谱中的特征成分。研究表明,15批山楂标准汤剂中共确定了7个特征峰,分离度较好,且峰面积较大,易于识别,使用参照物标定了3个特征峰成分,各共有峰相对保留时间的RSD值小于2.5%。所建立的山楂标准汤剂HPLC特征图谱方法可靠、稳定,为山楂配方颗粒质量控制提供了一定的参考。     

基于相关性的麻黄配方颗粒HPLC特征图谱研究

为更好地评价麻黄配方颗粒、饮片和水煎剂的一致性,分别建立麻黄配方颗粒、饮片和水煎剂的HPLC特征图谱,使用Wondasil C_(18)(4.6 mm×250 mm,5μm)色谱柱,以乙腈-0.1%磷酸为流动相梯度洗脱,柱温为30℃,流速为1.0 mL/min,检测波长为210 nm,分别得到10批麻黄配方颗粒、饮片和水煎剂的特征图谱,并进行关联性分析。结果表明,麻黄配方颗粒HPLC特征图谱中的13个共有峰均能在水煎剂中得到追踪,11个共有峰可在饮片中得到追踪。经方法学考察认为,所建立的麻黄配方颗粒HPLC特征图谱方法稳定,具有较高的重复性、稳定性及可信度,可用于麻黄配方颗粒、饮片和水煎剂的一致性评价,也可为麻黄配方颗粒的质量控制提供参考。     

辛紫通鼻颗粒HPLC多波长融合指纹图谱研究

目的研究建立辛紫通鼻颗粒的高效液相色谱多波长融合指纹图谱分析方法,为辛紫通鼻颗粒的质量控制提供依据。方法色谱柱为Waters Symmetry C_(18)(4.6 mm×250mm,5μm);混合流动相:流动相A为乙腈、流动相B为0.15 moL·L~(-1)磷酸二氢钠水溶液,梯度洗脱,检测波长250 nm、280 nm、327nm,柱温26℃。结果建立了辛紫通鼻颗粒指纹图谱,标示出15个共有峰,10批样品相似度均在0.987～0.998之间。结论:建立的多波长融合指纹图谱可用于辛紫通鼻颗粒的质量控制。     

白鲜皮饮片标准汤剂质量评价体系构建

为了提高白鲜皮配方颗粒的质量标准,采用15批白鲜皮饮片标准汤剂,建立了质量评价体系。第1次加入10倍的水、浸泡30 min、煎煮20 min,第2次加入8倍的水、煎煮15 min,以标准化工艺制备标准汤剂,采用HPLC法测定黄柏酮和梣酮的含量及指纹图谱。结果显示:15批白鲜皮标准汤剂中黄柏酮的转移率为25.08%~44.08%,平均转移率为34.79%,标准偏差为5.37%;梣酮转移率为22.63%~32.86%,平均转移率为27.94%,标准偏差为3.56%;出膏率为20.56%~34.42%,平均出膏率为29.05%,标准偏差为3.33%。采用中药指纹图谱相似度评价系统进行指纹图谱测定,得到共有峰10个,指认出白鲜碱、黄柏酮、梣酮3个峰。由此可知,白鲜皮饮片标准汤剂的制备工艺规范,样品质量稳定,指纹图谱相似度大于0.92,可用于白鲜皮配方颗粒的质量控制,并为白鲜皮饮片标准汤剂的应用和其他根茎类饮片的研究提供参考。     

基于UPLC特征图谱与主成分分析的白芷配方颗粒质量评价

为了评价不同厂家白芷配方颗粒的产品质量,建立了白芷配方颗粒的特征图谱与主成分分析方法。采用Waters Uplc Class H超高效液相色谱仪与Agilent Zorbax Eclipse Plus C18(2.1mm×100mm,1.7μm)色谱柱,以乙腈-水为流动相,柱温为25℃,流速为0.2mL/min,检测波长为254nm,利用指纹图谱相似度评价软件提取白芷配方颗粒特征图谱中的特征成分,使用参照物标定5个特征峰的成分;采用SPSS 19.0软件进行主成分分析,给出了不同厂家白芷配方颗粒在2个主成分上的分布图,并对不同厂家白芷配方颗粒进行了综合评分。结果表明:10批白芷配方颗粒特征图谱确定的13个特征峰中,指认出了花椒毒酚、水合氧化前胡素、欧前胡素、蛇床子素、异欧前胡素5种成分;以回归得到的3个主成分的矩阵回归系数与方差贡献值的乘积之和作为10批样品的综合评分,排名第一的综合评分为1.77。基于UPLC特征图谱与主成分分析法能够快速、有效地检测和评价白芷配方颗粒。     

基于UPLC指纹图谱的西洋参饮片、标准汤剂、配方颗粒的质量相关性研究

为了实现西洋参配方颗粒全生产过程的质量控制,采用超高效液相色谱法(UPLC)对其饮片、标准汤剂和配方颗粒的指纹图谱和量质传递进行了相关性研究。采用UPLC法测定18批西洋参饮片、标准汤剂、3批配方颗粒的指纹图谱、人参皂苷Rg₁,Re, Rb₁总量,以K值和各已知成分的转移率作为量值传递的评价指标,结合相似度评价法研究三者的相关性。结果表明：西洋参饮片、标准汤剂、配方颗粒指纹图谱均呈现8个共有特征峰,并指认出5个成分,三者的指纹图谱与相应对照指纹图谱及三者对照指纹图谱的相似度均大于0.95,人参皂苷Rg₁,Re, Rb₁的转移率及K值趋势一致,量值传递稳定。西洋参饮片、标准汤剂、配方颗粒的化学成分基本一致,三者具有良好的相关性。研究所得可对西洋参配方颗粒的质量标准研究提供实验及理论支持,并为后续以标准汤剂为基准的配方颗粒或经典方制剂质量控制提供了参考依据。     

牛蒡子标准汤剂质量评价体系的建立

为了提高牛蒡子标准汤剂的质量标准,制备了15批牛蒡子标准汤剂,通过对牛蒡苷含量及指纹图谱的研究,建立了牛蒡子标准汤剂的质量评价体系。第一煎加入8倍水,浸泡30min,煎煮20min;第二煎加入6倍水,煎煮15min,经浓缩、干燥后制得标准汤剂,应用HPLC法测定牛蒡子标准汤剂中牛蒡苷的含量及指纹图谱。结果显示:15批牛蒡子标准汤剂中牛蒡苷的转移率为21.3%～33.3%,平均转移率为27.3%,出膏率为7.1%～11.3%,平均出膏率为9.4%;通过中药指纹图谱相似度评价系统,确定了11个共有峰,通过对照品指认出了5个色谱峰,分别为绿原酸、咖啡酸、3,5-O-二咖啡酰基奎宁酸、牛蒡苷、牛蒡苷元。所建立的评价体系,牛蒡子标准汤剂制备规范,样品质量稳定,指纹图谱相似度大于0.94,对提高牛蒡子配方颗粒的质量标准具有一定的参考价值。     

On the Intricacies of the Chinese Guanxi: A Process Model of Guanxi Development

Guanxi (personal connection) has been identified as a necessary condition to do business successfully in China. In this paper, we seek a clear conceptual understanding of this prevalent construct and propose a three-stage model of guanxi development so as to stimulate systematic research in this area. Our conceptual and theoretical discussion of guanxi bases,guanxi objectives, and the operating principles at different stages of guanxi development will also help practitioners to use guanxi more effectively.     

The uniform distribution as a first practical approach to new product inventory management

It is common sense that the premises usually considered in inventory models have little applicability to new product inventory management. This paper develops a first practical approach to deal with this issue: the solution to the (Q, r) inventory model for uniform demand forecasts and lead-times. Based on the fact that the uniform distribution is defined by two parameters that are easy to estimate—maximum and minimum—this paper shows that such a premise may comprise a helpful and accurate decision support tool for managers until they begin to learn about the distribution characteristics of the demand during the lead-time.     

青风藤配方颗粒的制备及与传统汤剂的比较

为了研究青风藤配方颗粒制备工艺以及对青风藤配方颗粒与传统汤剂进行定性定量比较,运用正交试验方法,采用干法制粒,以出膏率、青藤碱含量为指标,优选青风藤配方颗粒制备工艺;采用薄层色谱法进行定性比较;以青藤碱为对照品,采用高效液相色谱法进行定量比较。青风藤配方颗粒最佳制备工艺如下:提取2次,加水量18倍(第1次加水量为10倍,第2次加水量为8倍),各煎煮1.0h。TLC结果显示,配方颗粒与传统汤剂化学成分的类型无明显差异。5批青风藤配方颗粒青藤碱含量分别为1.56%,1.58%,1.31%,1.20%和1.78%;5批青风藤传统汤剂青藤碱含量分别为0.94%,0.96%,0.85%,0.82%和1.02%。青风藤配方颗粒与传统汤剂中化学成分的类型基本相同,但青藤碱含量差异较大。     

Getting consumers to eat more whole-grains: The role of policy, information, and food manufacturers

The 2005 Dietary Guidelines were unique because they offered quantitative recommendations for consumption of whole-grains. This case study examines the hypothesis that the changed recommendations were responsible for the recent increase in retail sales and consumption of whole-grain food products. We find that release of the Dietary Guidelines and related media attention did increase availability and sales of whole-grain foods. A large impact on consumption occurred through reformulation of existing products, induced by competition among food suppliers. This study reveals the key role product reformulation plays in inter-firm competition and in realization of dietary changes recommended by public policy.     

Gibrat's Law: Are the Services Different?

Several noted surveys on intra-industry dynamics have reached the conclusion from a large body of evidence that Gibrat's Law does not hold. However, almost all of these studies have been based on manufacturing or large scale services such as banking and insurance industries. There are compelling reasons to doubt whether these findings hold for small scale services such as the hospitality industries. In this paper we examine whether the basic tenet underlying Gibrat's Law– that growth rates are independent of firm size – can be rejected for the services as it has been for manufacturing. Based on a large sample of Dutch firms in the hospitality industries the evidence suggests that in most cases growth rates are independent of firm size. Validation of Gibrat's Law in some sub-sectors of the small scale services suggests that the dynamics of industrial organization for services may not simply mirror that for manufacturing. The present paper includes a survey of nearly 60 empirical studies on firm growth rates.     

Knowledge and Values in Technology Education

This paper addresses two closely interrelated issues in Technology Education: knowledge and values. The starting point for the discussion is analysis of the nature of knowledge in technology education. Approaches for theorising knowledge will be analysed in this paper as well as problems associated with them. Three major types of problems are identified: problems with finding an appropriate approach for the analysis of technological knowledge; problems with a technocratic interpretation of technological knowledge for the purpose of its classification; and problems with establishing a consistent approach to distinguish common features of technological knowledge. A model that represents knowledge in technology education and the place of values in it is presented as a way of overcoming the problems specified. The claim is made that understanding of knowledge/values relationships can improve theoretical understanding of how technology education can be constructed.     

Firm Growth Under Sample Selection: Conditional <Emphasis>σ</Emphasis>-Convergence in Firm Size?

This paper tests the second, widely neglected implication of Gibrat’s law stating that the variance of firm size distribution increases over time. In contrast, learning models imply conditional σ-convergence in firm size. A unique data set of Austrian firms especially suited to account for sample selection effects is used to analyze the growth/size nexus of firms. The estimation results suggest that the predicted variance in firm size decreases only for firms of age 30 or below. For older age cohorts the hypothesis of a constant variance either cannot be rejected or increasing variances are found.     

Joint product management strategies for E. coli O157 and feedlot profits

The objective of this study was to investigate the associations of management strategies on Escherichia coli O157 and feedlot profits. Management practices that affect cattle performance were identified using ordinary least squares regressions, while a negative binomial regression was used to identify management practices that were associated with E. coli O157 prevalence. Findings support the hypothesis that E. coli O157 occurrences in the feedlot were not directly associated with cattle performance in the feedlot, which suggests potential for a downstream production externality problem. General categories of management strategies were associated with cattle performance and E. coli O157 occurrences and were consistent with past research. As implementation of enhanced food safety regulations potentially shift responsibility of ensuring safety of the food supply from a government based agency onto private firms, a portion of the costs of E. coli O157 outbreaks is likely to shift to feedlots in the future.