• MeSH
• laboratoře organizace a řízení   MeSH
• laboratorní informační systémy přístrojové vybavení   MeSH

• Konspekt
• Chemie. Mineralogické vědy
• NLK Obory
• chemie, klinická chemie
• NLK Publikační typ
• elektronické časopisy

• MeSH
• chemie přístrojové vybavení   MeSH
• klinické laboratorní techniky MeSH
• počítače využití   MeSH
• Publikační typ
• periodika MeSH

• Konspekt
• Chemie. Mineralogické vědy
• NLK Obory
• chemie, klinická chemie

• MeSH
• klinické laboratorní techniky metody   MeSH
• statistika jako téma metody   MeSH

• Publikační typ
• příručky MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• chemie, klinická chemie

Raman micro-spectroscopy technique offers a combination of relatively high spatial resolution with identification of components or mixtures of components in different sample areas, e.g. on the surface or the cross-section of a sample. This study is focused on the analysis of the tablets from pharmaceutical development with different technological parameters: (1) the manufacturing technology, (2) the particle size of the input API (active pharmaceutical ingredient) and (3) the quantitative composition of the individual excipients. These three mentioned parameters represent the most frequently solved problems in the field of reverse engineering in pharmacy. The investigation aims to distinguish tablets with the above-described technological parameters with limited subjective steps by Raman microscopy. Furthermore, non-subjective methods of Raman data analysis using advanced statistical analysis have been proposed, namely Principal Component Analysis, Soft Independent Modelling of Class Analogy and Linear Discriminant Analysis. The methods successfully distinguished and identified even very small differences in the analysed tablets within our study and provided objective statistic evaluation of Raman maps. The information on component and particle size distribution including their small differences, which is the critical parameter in the development of the original and generic products, was obtained due to combination of these methods. Even though each of these chemometric methods evaluates the data set from a different perspective, their mutual application on the problem of Raman maps evaluation confirmed and specified results on level that would be unattainable with the use of only one them.

• MeSH
• chemometrika MeSH
• farmacie * MeSH
• léčivé přípravky * MeSH
• pomocné látky MeSH
• Ramanova spektroskopie MeSH
• tablety MeSH
• Publikační typ
• časopisecké články MeSH

Although the identification of animal species and muscles have been reported previously, no studies have been found on the use of NIR spectroscopy to identify individual animals from the analysis of commercial meat cuts. The aim of this study was to evaluate the use of a portable near infrared (NIR) instrument combined with classical chemometrics methods [principal component analysis (PCA) and partial least squares discriminant analysis PLS-DA)] to identify the origin of individual goat animals using the spectral signature of their commercial cut. Samples were collected from several carcasses (6 commercial cuts x 24 animals) sourced from a commercial abattoir in Queensland (Australia). The NIR spectra of the samples were collected using a portable NIR instrument in the wavelength range between 950 and 1600 nm. Overall, the PLS-DA models correctly classify 82% and 79% of the individual goat samples using either the goat rack or loin cut samples, respectively. The study demonstrated that NIR spectroscopy was able to identify individual goat animals based on the spectra properties of some of the commercial cut samples analysed (e.g. loin and rack). These results showed the potential of this technique to identify individual animals as an alternative to other laboratory methods and techniques commonly used in meat traceability.

• Publikační typ
• časopisecké články MeSH

Organophosphorus compounds (OP) nerve agents are among the most toxic chemical substances known. Their toxicity is due to their ability to bind to acetylcholinesterase. Currently, some enzymes, such as phosphotriesterase, human serum paraoxonase 1 and diisopropyl fluorophosphatase, capable of degrading OP, have been characterized. Regarding the importance of bioremediation methods for detoxication of OP, this work aims to study the interaction modes between the human human deoxyuridine triphosphate nucleotidohydrolase (dUTPase) and Sarin and VX, considering their Rp and Sp enantiomers, to evaluate the asymmetric catalysis of those compounds. In previous work, this enzyme has shown good potential to degrade phosphotriesters, and based on this characteristic, we have applied the human dUTPase to the OP degradation. Molecular docking, chemometrics and mixed quantum and molecular mechanics calculations have been employed, showing a good interaction between dUTPase and OP. Two possible reaction mechanisms were tested, and according to our theoretical results, the catalytic degradation of OP by dUTPase can take place via both mechanisms, beyond being stereoselective, that is, dUTPase cleaves one enantiomer preferentially in relation to other. Chemometric techniques provided excellent assistance for performing this theoretical investigation. The dUTPase study shows importance by the fact of it being a human enzyme. Communicated by Ramaswamy H. Sarma.

• MeSH
• analýza hlavních komponent MeSH
• biodegradace MeSH
• katalytická doména MeSH
• kvantová teorie * MeSH
• lidé MeSH
• nervová bojová látka chemie   metabolismus   MeSH
• organofosforové sloučeniny chemie   metabolismus   MeSH
• organothiofosforové sloučeniny chemie   metabolismus   MeSH
• pyrofosfatasy metabolismus   MeSH
• sarin chemie   metabolismus   MeSH
• simulace molekulového dockingu * MeSH
• vodíková vazba MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Quantification models based on the processing of FTIR spectra by partial least squares regression (PLS) were created in order to develop a method for the determination of 2-ethylhexyl nitrate (2-EHN) in diesel fuels. The set of standards was prepared using 2-EHN, biodiesel (FAME) and various mineral diesel fuels (2-EHN free). The standards were prepared in the concentration range of 2-EHN of 0-2436mgkg-1. The set of the standards was divided into the calibration, validation and test sets. While the calibration set was used to build the model, validation set was used in order to optimize the model parameters. The test set of the standards was used to assess the predictive ability and repeatability of the model. Several hundreds of various models were developed and compared in order to find a suitable combination of the preprocessing methods and number of latent variables. The most promising model was developed using mean centered spectra in the form of their first derivative and smoothed using Gap-Segment derivative. The model showed quite good predictive ability and repeatability.

• MeSH
• benzin analýza   MeSH
• biopaliva analýza   MeSH
• dusičnany analýza   MeSH
• informatika * MeSH
• metoda nejmenších čtverců MeSH
• spektroskopie infračervená s Fourierovou transformací * MeSH
• Publikační typ
• časopisecké články MeSH

In recent years, several efforts have been made to develop quick and low cost bacterial identification methods. Genotypic methods, despite their accuracy, are laborious and time consuming, leaving spectroscopic methods as a potential alternative. Mass and infrared spectroscopy are among the most reconnoitered techniques for this purpose, with Raman having been practically unexplored. Some species of the bacterial genus Acinetobacter are recognized as etiological agents of nosocomial infections associated with high rates of mortality and morbidity, which makes their accurate identification important. The goal of this study was to assess the ability of Raman spectroscopy to discriminate between 16 Acinetobacter species belonging to two phylogroups containing taxonomically closely related species, that is, the Acinetobacter baumannii-Acinetobacter calcoaceticus complex (six species) and haemolytic clade (10 species). Bacterial spectra were acquired without the need for any sample pre-treatment and were further analyzed with multivariate data analysis, namely partial least squares discriminant analysis (PLSDA). Species discrimination was achieved through a series of sequential PLSDA models, with the percentage of correct species assignments ranging from 72.1% to 98.7%. The obtained results suggest that Raman spectroscopy is a promising alternative for identification of Acinetobacter species.

• MeSH
• Acinetobacter baumannii chemie   klasifikace   izolace a purifikace   MeSH
• Acinetobacter calcoaceticus chemie   klasifikace   izolace a purifikace   MeSH
• bakteriologické techniky MeSH
• infekce spojené se zdravotní péčí diagnóza   mikrobiologie   MeSH
• klasifikace MeSH
• lidé MeSH
• Ramanova spektroskopie * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

A combination of direct analysis in real time (DART) ionization coupled to time-of-flight mass spectrometry (TOFMS) and chemometrics was used for animal fat (lard and beef tallow) authentication. This novel instrumentation was employed for rapid profiling of triacylglycerols (TAGs) and polar compounds present in fat samples and their mixtures. Additionally, fat isolated from pork, beef, and pork/beef admixtures was analyzed. Mass spectral records were processed by principal component analysis (PCA) and stepwise linear discriminant analysis (LDA). DART-TOFMS profiles of TAGs were found to be more suitable for the purpose of discrimination among the examined fat types as compared to profiles of polar compounds. The LDA model developed using TAG data enabled not only reliable classification of samples representing neat fats but also detection of admixed lard and tallow at adulteration levels of 5 and 10% (w/w), respectively. The presented approach was also successfully applied to minced meat prepared from pork and beef with comparable fat content. Using the DART-TOFMS TAG profiles of fat isolated from meat mixtures, detection of 10% pork added to beef and vice versa was possible.

• MeSH
• diskriminační analýza MeSH
• hmotnostní spektrometrie přístrojové vybavení   metody   MeSH
• maso analýza   MeSH
• prasata MeSH
• řízení kvality MeSH
• skot MeSH
• triglyceridy analýza   MeSH
• tuky chemie   MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• hodnotící studie MeSH
• práce podpořená grantem MeSH