This is primarily a bugfix release with some small performance improvements. Visit https://quasar.codes to download and our Quasar to get started!Primary packagesOrange 3.34.0orange-spectroscopy 0.6.8python 3.9.15numpy 1.23.5scipy 1.9.3scikit-learn 1.1.3Important notesThis release bumps the included Python major version to 3.9. As a result, some installations (especially on Windows) will require a full uninstallation before installing the new version.Notable changesTile File widget can now accept multiple Preprocessor inputsSee included example workflow for a demonstration combining Preprocess Spectra and Integrate widgetsASCII column reader supports files with ";" commentsSome fixes to new separate baselines peak integration methodICYMIThere have been a few notable changes in the last few versions (1.6, 1.5):New peak area integration method which allows separate definition of the baseline pointsSpectra widget can now display custom peak labelsAtmospheric gas correction preprocessorWidgets now show little data table previews of their inputs/outputsFile widget allows explicit specification of file formatNew "Transform" widget category to distinguish widgets which load/create/view/annotate data, and those which modify the data table

The millisecond to microsecond time regime spans many dynamic processes such as reaction kinetics, molecular dynamics and complex system evolution. Accessing this time regime in the mid-infrared can be challenging and different existing approaches have inherent trade-offs such as requiring rapidly repeatable processes, sacrificing broadband spectral context or unacceptably low signal-to-noise.In this talk, a new laser-based instrument at the Mid-IR beamline capable of accessing these fast timescales with reasonable spectral bandwidth will be introduced. This spectrometer is an excellent complement to broadband FT-IR measurements where information about the dynamics of the system of interest is limited by the useful time resolution of rapid-scan measurements or by the reproducibility requirements of step-scan measurements. Examples of applications and practical sampling considerations will be presented.When: January 20, 2:00 pm CST (Saskatoon time)Where: The webinar will be on Webex. Please email us for connection details.

A dual infrared frequency comb spectrometer with heterodyne detection has been used to perform time-resolved electrochemical attenuated total reflectance surface-enhanced infrared absorption spectroscopy (ATR-SEIRAS). In collaboration with the Canadian Light Source and IRsweep, the desorption of a monolayer of a pyridine derivative with 10 μs time resolution and a detection limit of 5% of a monolayer was demonstrated. The applications of the method are potentially immense for the study of short lived adsorbed species during electrocatalysis. You can access the pre-print (https://harvest.usask.ca/handle/10388/12909) in the UofS open access repository.Analytical Chemistry.(https://pubs.acs.org/doi/10.1021/acs.analchem.0c00260).

Fourier transform infrared (FTIR) spectromicroscopy was used to study individual living cells of three closely-related species of the green algal genus Chlamydomonas. Three types of spectral variation were observed between individual cells within a single culture, as well as between different cultures: variation around a mean, individual outliers, and the presence of subpopulations. By understanding and controlling this variation, we were able to spectroscopically differentiate between the three closely-related species. Spectral differences were confirmed using principal component analysis, leading to an understanding of the biochemical differences between species. This work highlights the additional information obtained by studying individual cells, and has implications for more traditional bulk measurements.Analyst, (https://doi.org/10.1039/D0AN01386B )

Mid-IR is hosting a workshop!When: October 15-16, 2020Presenter: Christophe Sandt, Beamline Scientist, SOLEIL synchrotronTopics: Theory, Preprocessing Data, Data Exploration, Imaging, Classification and PredictionLocation: webinar, information sent with registrationWho can attend: Anyone who is interested! Please register:RegistrationHaving trouble with registration? Please send us an email with the subject Mid-IR workshop.AgendaOctober 14, 2020 - 12:00 (CST) → 14:00 (CST) Technical Help SessionProvide online technical support for the installation of Quasar to workshop attendees.October 15, 2020 - 08:00 (CST) → 10:00 (CST) First Session - Theory and Preprocessing DataTheoryData Collection StrategyNeed for Multivariate Analysis and ClusteringExample Applications (Bio-Spectroscopy)Preprocessing TheoryPreprocessing DataHands on training with QuasarQuality controlBaseline correction, normalization, derivationSmoothing/denoisingEMSC - Extended Multiplicative Scatter CorrectionAdvanced preprocessing that exist but not demonstrated (ATR, atmospheric suppression, interference fringes, KK, KM)October 15, 2020 - 12:00 (CST) → 14:00 (CST) Second Session - Data Exploration and ImagingData Exploration: PCAHands OnTheory and InterpretationPCA Classification (SIMCA)ImagingGenerate Images in QuasarManipulate Images: Graphical and "Intelligent" selection of DataOctober 16, 2020 - 08:00 (CST) → 10:00 (CST) Third Session - Classification and PredictionClassification and PredictionUnsupervised Clustering (K-Means, HCA)Supervised Clustering (KNN, CART, RFC, ANN, logit)Theory: Calibration and ValidationTest and ScorePredictionChristophe Sandt - BiographyChristophe Sandt was trained as a biochemist and is currently beamline scientist at the SOLEIL synchrotron near Paris, France. He earned a PhD in Biospectroscopy from the Pharmacy University of Reims Champagne-Ardenne under the guidance of Prof. Manfait and Sockalingum. He has a 20 year long experience in the field of vibrational microspectroscopy of biological materials, cells and tissues including two post-doctoral fellowships in Canada, at the Chemistry Department of Université de Montréal working with Prof. Lafleur, and at the Chemistry Department of St Francis Xavier University with Prof. Pink and Smith-Palmer. His first research interests focused on the early identification of pathogenic microorganisms by infrared spectroscopy, the study of biocide penetration in bacterial biofilms with ATR-FTIR, and pioneering the analysis of bacterial biofilms by Raman microspectroscopy. He joined the French national synchrotron light source, SOLEIL, in 2008 and has since been helping scientists perform experiment in various fields of science such as cultural heritage, plant biology, cell chemistry, catalysis, astrophysics... He has used the bright IR synchrotron light to conduct various studies in biochemistry: to profile induced pluripotent and embryonic stem cells, to monitor tyrosine kinase activity in multiresistant hematopietic progenitor cells, to study the chemical changes associated with tumor hypoxia, to follow the penetration of IR probes in living cells and tissues, to study abnormal protein conformation in diverse neurodegenerative diseases.

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Mid-IR is open for beamtime.Have an active project? Interested in starting a new project?Please contact beamline staff to discuss how to implement your experiments.Information on shipping and sample in the user guideADD + CHANGE