Quality control data

In order to accurately interpret the importanee of the revealed lipid ehanges, it is essential for the researchers to understand the functions of individual lipid classes, subclasses, and individual molecular species. Therefore, an important part of this chapter is to describe the functions of these lipid classes and individual species with examples. 

It is well known that membrane lipids are manifest in the majority of the cells and organs and follow a specific pattern. For example, the levels of PC and PE classes are comparable the content of anionic GPL species is approximately 10% of total lipids SM only counts for approximately 5% of total lipids the ratio of PC + SM vi. PE + anionic lipids is roughly one etc. [7, 9, 10]. Obviously, this knowledge should be followed and can generally be used for data quality control if global lipidomics analysis is the goal of a study. 

Another important approach to conduct data quality control is to compare the determined data with those reported in the literature. Although most of the previous studies with conventional methods only report the total amount of individual lipid classes without details of molecular species, these data at least can provide a rough comparison to the current studies. 

Many lipidomics studies are carried out with human plasma (or serum) samples. A couple of facts about plasma samples should be useful for data quality control. First, plasma lipoproteins (e.g., VLDL, LDL, and HDL) are enriched with lipids [7]. The lipid compositions of these lipoproteins depend on the type of lipoproteins. The mass levels of cholesteryl esters and TAG species decrease from VLDL to HDL while the contents of phospholipids (including SM) and free cholesterol are in a reversed order in these lipoproteins. Second, the concentrations of plasma phospholipids are in an order of PC SM PE lysoPC PI lysoPE PS PG PA [ 11 ]. 

It should be recognized that different cell types possess different types of lipids (classes, subclasses, and individual molecular species). For example, plants lack plas-malogen species cholesterol is also unique to mammalian mammalian does not possess the machinery to synthesize essential fatty acids and the numbers and locations of double bonds in fatty acid species in eukaryotes are not randomly present. This nature of lipids in biological samples can be used as a criterion for data quality control. Violation of such a rule indicates something wrong in MS identification of lipid species. 

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Ihnat M (1998a) Reference materials for data quality control. In Kalra YP, ed. Handbook of Reference Methods for Plant Analysis, pp 209-220. CRC Press, Boca Raton. 

Technical data, Quality Control Equipment Co., Des Moines, Iowa. 

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Data Conditioning of Environmental Geochemical Data Quality Control Procedures Used in the British Geological Survey s Regional Geochemical Mapping Project... 

C. Testa, D. Desideri, M. A. Meli, C. Roselli, New radiochemical procedures for environmental actinide measurements and data quality control, J. Radioanal. Nucl. Chem., 194 (1995), 141-149. 

Today, a number of pharmaceutical companies dealing with HTS reach a turnover of more than 15 different assay systems a year, in which 300,000 samples or even more are tested. This confronts the scientist with more than 5,000,000 data points which point to the need for efficient automation at all stages of HTS, even in data collection, data quality control and analysis. Robots, especially large systems integrated with multiple peripheral devices, are prominent at present. 

With respect to data quality control in water, a European thematic network, METROPOLIS (2004), has identified a few typical problem areas, for example ... 

Considerations of overall data quality assurance include, data quality, data quality control, standard operating procedures (SOP), good laboratory practices (GLP), and concepts of accuracy, precision, and reliability. Also included are reference methods, standard methods, referee methods, official methods (from organizations or in-depth individual studies), and high-reliability methods. 

Currently, pathologists evaluate immunohistochemical or in situ hybridization studies. However, many groups are actively evaluating automated methods. The data extracted from the evaluation can be conveniently divided into two main areas quality control data and experimental data. Quality control data include information on the integrity of the core (e.g., presence/absence of tumor in the current section), as well as any internal controls that may relevant ... 

Standard test methods giving apparent properties are best suited to quality control, and only in relatively few cases are they ideal for design data. Quality control tests are the most easily established, and many existing methods fulfil this need. In seeking an improve-tneiit in test procedure it is not always a more accurate test that is required. Depending on the purpose for which testing is undertaken, it m iy be quicker or cheaper tests that are required, or most important of all, tests that are relevant to service performance. 

The Simplified Molecular Input Line Entry System (SMILES) strings ofthe structures in the data set were canonicalized, the charges were standardized, the additional fragments and salts were removed, and duplicate or invalid structures were identified and removed using the KNIME workflow environment [29]. Further data quality control was performed by the Eli Lilly AD ME group. 

Another presumptive application of pattern recognition techniques is the interpretation of quality control data- Two such problems were described by Kowalski C147]- Quality control measurements were performed to characterize production items of an explosive in one case and of beryllium parts in the other. Pattern recognition methods may be useful for the evaluation of specification limits. If no classification method is capable of distinguishing between good and poor items, then it may be supposed that the data (quality control measurements) are insufficient-Feature selection and combination of features may indicate those measurements which provide most information on the separation into good and poor items C1483. 

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