卷烟材料组合搭配对主流烟气量及过滤效率的影响

为研究卷烟纸、成型纸、接装纸及嘴棒组合搭配对"中式卷烟"焦油量、烟气烟碱量、烟气水分、烟气一氧化碳量及过滤效率的影响,尝试采用L_(27)(3~(13))裂区正交设计方法对RR卷烟进行在线试验和取样.检测结果经过直观分析、方差分析及贡献率分析,结果表明:嘴棒长度、吸阻及接装纸透气度是影响试验指标的高度显著因素及重要因素.所以重点对嘴棒长度、吸阻及接装纸透气度进行调整和控制,可以很好地实现卷烟产品的质量控制,减少产品质量波动,降低产品成本.使用该方法可快捷、高效、经济、准确地寻找并确定卷烟材料多因素对卷烟主流烟气量及过滤效率的影响规律及卷烟产品的材料搭配优化方案.从而实现卷烟产品材料搭配精益化,满足烟草企业的实际需求.     

Implementation of a quality management system in meteorological practice in Serbia

An optional approach in the meteorological service Quality Management System (QMS) based on the case study of the Republic Hydrometeorological Service (MHS) of Serbia is presented and discussed in this paper. The idea is to use the ISO/IEC 17025 standard as a base for its QMS development. Main reasons for such a decision and the elements of the implemented solution are presented and discussed. Meteorological testing processes of the MHS of Serbia and relevant ISO/IEC 17025 scope of accreditation are presented. After establishing competencies in meteorological, environmental, and hydrological testing, the MHS of Serbia will develop an integrative ISO 9001 QMS. The Serbian case study could be taken into consideration as one of the options related to the future World Meteorological Organization Quality Management Framework.     

A comparison of location estimators for interlaboratory data contaminated with value and uncertainty outliers

While estimation of measurement uncertainty (MU) is increasingly acknowledged as an essential component of the chemical measurement process, there is little agreement on how best to use even nominally well-estimated MU. There are philosophical and practical issues involved in defining what is “best” for a given data set; however, there is remarkably little guidance on how well different MU-using estimators perform with imperfect data. This report characterizes the bias, efficiency, and robustness properties for several commonly used or recently proposed estimators of true location, μ, using “Monte Carlo” (MC) evaluation of “measurement” data sets drawn from well-defined distributions. These synthetic models address a number of issues pertinent to interlaboratory comparisons studies. While the MC results do not provide specific guidance on “which estimator is best” for any given set of real data, they do provide broad insight into the expected relative performance within broadly defined scenarios. Perhaps the broadest and most emphatic guidance from the present study is that (1) well-estimated measurement uncertainties can be used to improve the reliability of location determination and (2) some approaches to using measurement uncertainties are better than others. The traditional inverse squared uncertainty-weighted estimators perform well only in the absence of unrepresentative values (value outliers) or underestimated uncertainties (uncertainty outliers); even modest contamination by such outliers may result in relatively inaccurate estimates. In contrast, some inverse total variance-weighted-estimators and probability density function area-based estimators perform well for all scenarios evaluated, including underestimated uncertainties, extreme value outliers, and asymmetric contamination.     

Aspects of auditing in clinical laboratories

Quality and patient safety are terms that both providers and recipients of healthcare are very familiar with. Accreditation is another term that is closely linked to quality and patient safety. Audit is a systematic, independent, and documented process for obtaining evidence and evaluating it objectively to determine the extent to which audit criteria are fulfilled. Accreditation and audit are integral components of the same process. Three different types of audit are well recognized—internal, external, and co-operative. Reading of relevant documents, observation of laboratory practices, and asking open-ended probing questions are important auditing techniques. For auditing to be successful, experienced, qualified, and well trained auditors are essential. Furthermore, the auditor should be open-minded, not prejudiced, a team player and effective communicator, both in writing and verbally. In many instances, the emphasis for seeking laboratory accreditation has shifted from building quality systems—to produce reliable results and ensure patient safety—to just passing the inspection. Recently, the emphasis for laboratory quality improvement has been placed on pre and post-analytical processes in preference to analytical quality. The analytical quality of laboratory results is still far from ideal and it may be detrimental if less emphasis is placed on this aspect of laboratory medicine. Auditing or on-site inspection as a regulatory tool does not work or present a realistic picture of laboratory quality. A continuous quality improvement approach will help laboratories to build quality into their systems. Presented at the Conference “Excellence in Laboratory Medicine”, November 2007, Al Ain, United Arab Emirates.     

大别山区野生黎豆中微量元素的测定与品质评价

采用了火焰原子吸收光谱法测定了大别山区野生黎豆中钙、镁、锌、铜、铁、锰 6 种微量元素的含量,采用硝酸_高氯酸的混酸湿法消化样品,并用电感耦合等离子体原子发射光谱法对测定结果作了对照,又将测定结果与黑豆、黄豆中 6 种微量元素钙、镁、锌、铜、铁和锰的含量作了比较,论证了大别山区野生黎豆具有较高的营养价值,为黎豆的广泛开发提供了科学的依据.     

Identification and quality evaluation of different processed products of Aconitum carmichaelii by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry and ultra-high-performance liquid chromatography-tandem mass spectrometry

Aconitum carmichaelii is widely used to treat chronic and intractable diseases due to its remarkable curative effect, but it is also a highly toxic herb with severe cardiac and neurotoxicity. It has been combined with honey for thousands of years to reduce toxicity and enhance efficacy, but there has been no study on the chemical constituent changes in the honey-processing so far. In this study, the chemical constituents of A. carmichaelii before and after honey-processing were characterized by ultra-high-performance liquid chromatography-quadrupole time-of-flight tandem mass spectrometry. The results showed that a total of 118 compounds were identified, of which six compounds disappeared and five compounds were newly produced after honey-processing, and the cleavage pathway of main components was elucidated. At the same time, 25 compounds were found to have significant effects on different products, among which four compounds with the biggest difference were selected for quantitative analysis by ultra-high-performance liquid chromatography-tandem mass spectrometry. This study not only explained the chemical differences between the different products, but also helped to control the quality of the honey-processed products more effectively, and laid a foundation for further elucidating the mechanism of chemical constituent change during the honey-processing of A. carmichaelii.     

High-performance liquid chromatography micro-fraction bioactive evaluation combined with countercurrent chromatographic separation of antioxidants from Citrus peel and their tyrosinase inhibition activities

In the present study, high-performance liquid chromatography micro-fraction bioactive evaluation and high speed countercurrent chromatography were performed on screening, identification and isolation of antioxidants from Citrus peel. Three compounds were screened as antioxidants and tyrosinase inhibitors using 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) radical cation scavenging assay and tyrosinase activity test, then they were identified as eriocitrin, narirutin and hesperidin. Moreover, the solvent system ethyl acetate-n-butanol-water (6:4:10, v/v/v) was used for separation of ethyl acetate extract of Citrus peel by high speed countercurrent chromatography. In total, 0.45 mg of eriocitrin with 87.10% purity, 2.04 mg of narirutin with 95.19% purity and 1.35 mg of hesperidin with 95.19% purity were obtained from 20 mg of ethyl acetate extract of Citrus peel in a single run and then each component was subjected to 2,2′-azino-bis (3-ethyl-benzothiazoline-6-sulfonic acid) radical cation scavenging assay and tyrosinase inhibition assay. Eriocitrin showed great antioxidant activity (the half-maximum concentration: 3.65 µM) and tyrosinase inhibition activity (the half-maximum concentration: 115.67 µM), while narirutin and hesperidin exhibited moderate activity. Tyrosinase inhibition activity for eriocitrin in vitro was reported for the first time. Furthermore, molecular docking between eriocitrin and mushroom tyrosinase was also studied.     

Qualitative identification and quantitative comparison of Physochlainae Radix from different regions based on chemometric methods

Physochlainae Radix (PR) is an essential herbal medicine that has been generally applied for treating cough and asthma. In this study, a comprehensive strategy for quality evaluation of PR from different origins was established by integrating qualitative identification, quantitative analysis, and chemometric methods. A total of 58 chemical components were identified by ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS), and a sensitive and rapid UHPLC-QqQ-MS/MS method was established for the simultaneous determination of 12 compounds. In addition, multivariate statistical analysis was applied for discriminant analysis to compare the differences among 30 batches of PR samples. The results showed that the 30 batches of PR collected from four provinces could be clustered into three categories, in which scoparone, protocatechuic acid, tropic acid, and scopolin were important components to distinguish the primary and non-primary producing areas, as well as superior and inferior products of PR. Chemometric results were consistent and validated each other, and systematically explained the intrinsic quality characteristics of PR. This study first demonstrated that LC-MS combined with multivariate statistical analysis, provided a comprehensive and effective means for quality evaluation of PR.     

Matrix solid-phase dispersion combined with micro-fractionation bioactivity evaluation screening polymethoxylated flavones from Citrus peels

Polymethoxyflavones were a unique class of natural and safe flavonoids containing two or more methoxy groups, which were also the most abundant edible part in Citrus peel. The optimum condition in the process of selective extraction of polymethoxylated flavones from Citrus peel by matrix solid-phase dispersion (MSPD) was as follows: SBA-15 as adsorbent, ethyl acetate as eluent, the mass ratio of adsorbent to sample 1:1, and the mixture of sample and adsorbent was ground for 3 min. Twelve antioxidants were successfully screened by micro-fractionation bioactivity evaluation assay, in which four of them were flavonoid glycosides, seven of them were polymethoxylated flavones, and one was phenylpropanoid. 1-sinapoly-β-D-glucopyranoside (1) was reported for the first time in Citrus peel. And antioxidant capacity of 1-sinapoly-β-D-glucopyranoside, 5, 7, 8, 3′, 4′, 5′-hexamethoxyflavone (6), hexamethoxyflavone (11), and 5, 6, 7, 4′-tetramethoxyflavone (7) were reported for the first time. Nobiletin (compound 8), 3, 5, 6, 7, 8, 3′, 4′-heptamethoxyflavone (9) and tangeretin (10) were isolated and purified by countercurrent chromatography combined with preparative liquid chromatography. Antioxidant activity evaluation indicated that the three isolated polymethoxylated flavones owned similar antioxidant activity. This study indicated that MSPD combined with micro-fractionation bioactive evaluation was efficient in screening bioactive compounds for rapid extraction and effective pinpointing bioactive substances in natural products.     

Ensuring Quality of Experience in the Connected Home: A New Battleground for Quality of Experience Differentiation

ABSTRACT

The connected home is a critical part of the network—but one that has seen little in the way of true investment in recent years. With customer loyalty and churn directly linked to quality of experience, this is a part of the network that no players in the supply chain can afford to ignore any longer. Beyond broadband experience, the addition of smart technology to the connected home also represents one of the biggest revenue growth areas in the consumer telecoms market for some time. From both a churn-reduction and a revenue-growth perspective, investment in the connected home network must accelerate. This article outlines the key trends identified by Ovum in the connected home space for 2016 and beyond.