Partial Least-Squares with Residual Bilinearization

Olivieri, Alejandro C.; Escandar, Graciela M.

doi:10.1016/b978-0-12-410408-2.00009-0

Cited by 7 publications

(5 citation statements)

References 25 publications

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“…However, since in the current study the temporal evolution for different parameters is not identical, this algorithm is not applicable, due to a lack of trilinearity present in these datasets [ 34 ]. On the other hand, algorithms based on partial least square (PLS) are generally suitable for second-order calibration data analysis, but the results obtained as loadings and scores do not provide an approximation to the pure constituent profiles [ 46 ]. Thus, these algorithms are not applicable when spectral information is desired.…”

Section: Resultsmentioning

confidence: 99%

EC-QCL mid-IR transmission spectroscopy for monitoring dynamic changes of protein secondary structure in aqueous solution on the example of β-aggregation in alcohol-denaturated α-chymotrypsin

et al. 2016

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In this work, a novel EC-QCL-based setup for mid-IR transmission measurements in the amide I region is introduced for monitoring dynamic changes in secondary structure of proteins. For this purpose, α-chymotrypsin (aCT) acts as a model protein, which gradually forms intermolecular β-sheet aggregates after adopting a non-native α-helical structure induced by exposure to 50 % TFE. In order to showcase the versatility of the presented setup, the effects of varying pH values and protein concentration on the rate of β-aggregation were studied. The influence of the pH value on the initial reaction rate was studied in the range of pH 5.8–8.2. Results indicate an increased aggregation rate at elevated pH values. Furthermore, the widely accessible concentration range of the laser-based IR transmission setup was utilized to investigate β-aggregation across a concentration range of 5–60 mg mL−1. For concentrations lower than 20 mg mL−1, the aggregation rate appears to be independent of concentration. At higher values, the reaction rate increases linearly with protein concentration. Extended MCR-ALS was employed to obtain pure spectral and concentration profiles of the temporal transition between α-helices and intermolecular β-sheets. Comparison of the global solutions obtained by the modelled data with results acquired by the laser-based IR transmission setup at different conditions shows excellent agreement. This demonstrates the potential and versatility of the EC-QCL-based IR transmission setup to monitor dynamic changes of protein secondary structure in aqueous solution at varying conditions and across a wide concentration range.Graphical abstractEC-QCL IR spectroscopy for monitoring protein conformation changeElectronic supplementary materialThe online version of this article (doi:10.1007/s00216-016-9464-5) contains supplementary material, which is available to authorized users.

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Section: Resultsmentioning

confidence: 99%

EC-QCL mid-IR transmission spectroscopy for monitoring dynamic changes of protein secondary structure in aqueous solution on the example of β-aggregation in alcohol-denaturated α-chymotrypsin

et al. 2016

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“…In this work, column‐wise augmentation of EEM was considered (see Figure 1). For further details, please refer to the specific literature 29 . In a column‐wise augmented matrix decomposition, S represents the profiles of N species in the non‐augmented mode, which is common to all samples, whereas, C aug comprises the profiles of N species in the augmented mode, in each of the submatrices of D aug .…”

Section: Methodsmentioning

confidence: 99%

Prospective inference of bioprocess cell viability through chemometric modeling of fluorescence multiway data

Chiappini

Azcarate

Alcaráz

et al. 2021

Biotechnol Progress

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In this investigation, the fermentation step of a standard mammalian cell-based industrial bioprocess for the production of a therapeutic protein was studied, with particular emphasis on the evolution of cell viability. This parameter constitutes one of the critical variables for bioprocess monitoring since it can affect downstream operations and the quality of the final product. In addition, when the cells experiment an unpredictable drop in viability, the assessment of this variable through classic offline methods may not provide information sufficiently in advance to take corrective actions. In this context, Process Analytical Technology (PAT) framework aims to develop novel strategies for more efficient monitoring of critical variables, in order to improve the bioprocess performance. Thus, in this work, a set of chemometric tools were integrated to establish a PAT strategy to monitor cell viability, based on fluorescence multiway data obtained from fermentation samples of a particular bioprocess, in two different scales of operation. The spectral information, together with data regarding process variables, was integrated through chemometric exploratory tools to characterize the bioprocess and stablish novel criteria for the monitoring of cell viability. These findings motivated the development of a multivariate classification model, aiming to obtain predictive tools for the monitoring of future lots of the same bioprocess. The model could be satisfactorily fitted, showing the non-error rate of prediction of 100%.

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“…Finally, the third category of multi-way chemometric approaches is constituted by latent variable-based models, essentially, the regression variants U-PLS and N-PLS. The PLS model was originally conceived for first-order calibration, i.e., senso strictum is only able to exploit the first-order advantage [53]. However, the PLS philosophy was extended to higher-order calibration, where the second-order advantage can be achieved by coupling the model to the RML methodology [54].…”

Section: Lc Multi-way Data Analysis: Chemometric Models and Algorithmsmentioning

confidence: 99%

“…In U-PLS/RML, during the calibration step, a classical PLS model is built with a set of unfolded multi-way data, disposed in a matrix X PLS , which is then subjected to the following decomposition [53]:…”

Section: Lc Multi-way Data Analysis: Chemometric Models and Algorithmsmentioning

confidence: 99%

“…where t is the score vector of a given test sample, obtained by projection of an unfolded test signal onto the space spanned by the PLS calibration loadings. If a given test sample contains unmodelled constituents, the PLS prediction residual might be abnormally large compared to the expected noise level [53]. Under these circumstances, the RML methodology intends to decompose the part of the test data unexplained by PLS, assuming that the residuals can be rearranged into a multilinear array.…”

Section: Lc Multi-way Data Analysis: Chemometric Models and Algorithmsmentioning

confidence: 99%

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Chromatographic Applications in the Multi-Way Calibration Field

et al. 2021

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In this review, recent advances and applications using multi-way calibration protocols based on the processing of multi-dimensional chromatographic data are discussed. We first describe the various modes in which multi-way chromatographic data sets can be generated, including some important characteristics that should be taken into account for the selection of an adequate data processing model. We then discuss the different manners in which the collected instrumental data can be arranged, and the most usually applied models and algorithms for the decomposition of the data arrays. The latter activity leads to the estimation of surrogate variables (scores), useful for analyte quantitation in the presence of uncalibrated interferences, achieving the second-order advantage. Recent experimental reports based on multi-way liquid and gas chromatographic data are then reviewed. Finally, analytical figures of merit that should always accompany quantitative calibration reports are described.

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Partial Least-Squares with Residual Bilinearization

Cited by 7 publications

References 25 publications

EC-QCL mid-IR transmission spectroscopy for monitoring dynamic changes of protein secondary structure in aqueous solution on the example of β-aggregation in alcohol-denaturated α-chymotrypsin

EC-QCL mid-IR transmission spectroscopy for monitoring dynamic changes of protein secondary structure in aqueous solution on the example of β-aggregation in alcohol-denaturated α-chymotrypsin

Prospective inference of bioprocess cell viability through chemometric modeling of fluorescence multiway data

Chromatographic Applications in the Multi-Way Calibration Field

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