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The Journal of Physical Chemistry. A Jun 2022Structural isomers, such as conformers or tautomers, are of significant importance across chemistry and biology, as they can have different functionalities. In gas-phase...
Structural isomers, such as conformers or tautomers, are of significant importance across chemistry and biology, as they can have different functionalities. In gas-phase experiments using molecular beams, formation of many different isomers cannot be prevented, and their presence significantly complicates the assignment of spectral lines. Current isomer-resolved spectroscopic techniques heavily rely on theoretical calculations or make use of elaborate double-resonance schemes. We show here that isomer-resolved spectroscopy can also be performed using a single tunable laser. In particular, we demonstrate single-color isomer-resolved spectroscopy by utilizing electrostatic deflection to spatially separate the isomers. We show that for 3-aminophenol we can spatially separate the and conformers and use these pure samples to perform high-resolution REMPI spectroscopy, making the assignment of transitions to a particular isomer trivial, without any additional information. This approach allows one to add isomer specificity to any molecular-beam-based experiment.
Topics: Isomerism; Spectrophotometry, Infrared; Spectrophotometry, Ultraviolet; Static Electricity
PubMed: 35648652
DOI: 10.1021/acs.jpca.2c02277 -
The Analyst Mar 2020Ultrafast two-dimensional infrared (2D-IR) spectroscopy has provided valuable insights into biomolecular structure and dynamics, but recent progress in laser technology... (Review)
Review
Ultrafast two-dimensional infrared (2D-IR) spectroscopy has provided valuable insights into biomolecular structure and dynamics, but recent progress in laser technology and data analysis methods have demonstrated the potential for high throughput 2D-IR measurements and analytical applications. Using 2D-IR as an analytical tool requires a different approach to data collection and analysis compared to pure research applications however and, in this review, we highlight progress towards usage of 2D-IR spectroscopy in areas relevant to biomedical, pharmaceutical and analytical molecular science. We summarise the technical and methodological advances made to date and discuss the challenges that still face 2D-IR spectroscopy as it attempts to transition from the state-of-the-art laser laboratory to the standard suite of analytical tools.
Topics: Animals; Equipment Design; Humans; Models, Molecular; Protein Conformation; Proteins; Spectrophotometry, Infrared
PubMed: 32051976
DOI: 10.1039/c9an02035g -
Theriogenology Jun 2016This article is the result of the work of the andrology task-force of the Association of Applied Animal Andrology, American College of Theriogenologists, European... (Review)
Review
This article is the result of the work of the andrology task-force of the Association of Applied Animal Andrology, American College of Theriogenologists, European College of Animal Reproduction, Society for Theriogenology, and National Association of Animal Breeders. It is intended to serve as a comprehensive reference on methods to evaluate sperm concentration and to contribute to the adoption of best practices in veterinary andrology laboratories. The information covered in the article includes sample preparation and the use of manual counts, spectrophotometers, computer-assisted semen analysis, NucleoCounter, and flow cytometry. Emphasis is given to the principles of the methods and equipment, performing the evaluation, and common mistakes and/or pitfalls. In addition, the precision and accuracy of the different methods are also discussed.
Topics: Flow Cytometry; Image Processing, Computer-Assisted; Practice Guidelines as Topic; Semen Analysis; Species Specificity; Specimen Handling; Spectrophotometry; Sperm Count
PubMed: 27045626
DOI: 10.1016/j.theriogenology.2016.01.002 -
Gastrointestinal Endoscopy Clinics of... Apr 2009Reflectance spectroscopy is an emerging technology which provides rapid and safe evaluation of tissue for dysplasia and ischemia. The probe-based devices can be passed...
Reflectance spectroscopy is an emerging technology which provides rapid and safe evaluation of tissue for dysplasia and ischemia. The probe-based devices can be passed through most endoscopes. Current applications include detection of dysplasia in Barrett's esophagus, colitis, and colon polyps.
Topics: Diagnosis, Differential; Endoscopy, Gastrointestinal; Gastrointestinal Neoplasms; Gastrointestinal Tract; Humans; Ischemia; Light; Precancerous Conditions; Scattering, Radiation; Sensitivity and Specificity; Spectrophotometry
PubMed: 19423021
DOI: 10.1016/j.giec.2009.02.008 -
International Journal of Molecular... Apr 2023The review briefly describes various types of infrared (IR) and Raman spectroscopy methods. At the beginning of the review, the basic concepts of biological methods of... (Review)
Review
The review briefly describes various types of infrared (IR) and Raman spectroscopy methods. At the beginning of the review, the basic concepts of biological methods of environmental monitoring, namely bioanalytical and biomonitoring methods, are briefly considered. The main part of the review describes the basic principles and concepts of vibration spectroscopy and microspectrophotometry, in particular IR spectroscopy, mid- and near-IR spectroscopy, IR microspectroscopy, Raman spectroscopy, resonance Raman spectroscopy, Surface-enhanced Raman spectroscopy, and Raman microscopy. Examples of the use of various methods of vibration spectroscopy for the study of biological samples, especially in the context of environmental monitoring, are given. Based on the described results, the authors conclude that the near-IR spectroscopy-based methods are the most convenient for environmental studies, and the relevance of the use of IR and Raman spectroscopy in environmental monitoring will increase with time.
Topics: Vibration; Biological Monitoring; Spectrophotometry, Infrared; Spectrum Analysis, Raman; Spectroscopy, Near-Infrared; Spectroscopy, Fourier Transform Infrared
PubMed: 37108111
DOI: 10.3390/ijms24086947 -
International Journal of Molecular... Nov 2023Hematological diseases, due to their complex nature and diverse manifestations, pose significant diagnostic challenges in healthcare. The pressing need for early and... (Review)
Review
Hematological diseases, due to their complex nature and diverse manifestations, pose significant diagnostic challenges in healthcare. The pressing need for early and accurate diagnosis has driven the exploration of novel diagnostic techniques. Infrared (IR) spectroscopy, renowned for its noninvasive, rapid, and cost-effective characteristics, has emerged as a promising adjunct in hematological diagnostics. This review delves into the transformative role of IR spectroscopy and highlights its applications in detecting and diagnosing various blood-related ailments. We discuss groundbreaking research findings and real-world applications while providing a balanced view of the potential and limitations of the technique. By integrating advanced technology with clinical needs, we offer insights into how IR spectroscopy may herald a new era of hematological disease diagnosis.
Topics: Humans; Spectroscopy, Fourier Transform Infrared; Spectrophotometry, Infrared; Hematology; Hematologic Diseases
PubMed: 38069330
DOI: 10.3390/ijms242317007 -
International Journal of Molecular... Dec 2022The paper compares the experimental FT-IR, UV-vis, and H NMR spectra of isoconazole and bifonazole with the density functional theory (DFT) calculations using different...
The paper compares the experimental FT-IR, UV-vis, and H NMR spectra of isoconazole and bifonazole with the density functional theory (DFT) calculations using different functionals. The results were compared with previously reported data related to their analogue, posaconazole. The analysis of calculated IR spectra with use of CAM-B3LYP (isoconazole) or B3LYP (bifonazole) functionals shows good accordance with the experimental IR spectrum. The best compatibility between the experimental and theoretical UV spectra was observed with the use of B3LYP or wB97XD functionals for isoconazole or bifonazole, respectively. The reason for the difference in the UV-vis spectra of isoconazole and bifonazole was discussed based on linear response time-dependent DFT and natural bond orbital methods. The calculated H NMR spectrum shows that the DFT formalism, particularly the B3LYP functional, give an accurate description of the isoconazole and bifonazole chemical shifts.
Topics: Models, Molecular; Spectroscopy, Fourier Transform Infrared; Spectrum Analysis, Raman; Spectrophotometry, Ultraviolet; Quantum Theory; Thermodynamics; Vibration
PubMed: 36613962
DOI: 10.3390/ijms24010520 -
Analytica Chimica Acta Oct 2023Sulfamethoxazole (SMX) is one of the most widely used antibiotics worldwide and has been detected at high concentrations in wastewater treatment plant effluents and...
UV-Vis absorption spectrophotometry and LC-DAD-MS-ESI(+)-ESI(-) coupled to chemometrics analysis of the monitoring of sulfamethoxazole degradation by chlorination, photodegradation, and chlorination/photodegradation.
Sulfamethoxazole (SMX) is one of the most widely used antibiotics worldwide and has been detected at high concentrations in wastewater treatment plant effluents and river waters. In this study, the SMX degradation process combining the simultaneous chlorine oxidation and UV photodegradation is assessed and compared with both photodegradation and chlorine oxidation processes individually. Photodegradation and Chlorine/UV tests were performed using Suntest CPS equipment. Different experimental techniques, including UV-Visible spectrophotometry and liquid chromatography coupled to a diode array detector and positive and negative ionization mass spectrometry (LC-DAD-MS-ESI(+)-ESI(-)), were used to evaluate the degradation reaction of SMX. All the analytical data generated have been processed with the Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) method to monitor, resolve, and identify the several transformation products generated during the studied degradation processes. A new data fusion analysis strategy is proposed to examine the three processes simultaneously (with only photodegradation, only chlorination, and simultaneous chlorination+photodegradation). Combined with the analysis of different analytical techniques individually (spectrophotometry, LC-DAD, and LC-MS), the fusion of all generated data improved the description of the degradation processes. Detection using DAD allowed a better correspondence among the species monitored spectrophotometrically (UV-Vis) with those analyzed chromatographically. On the other side, detection using MS in both positive and negative acquisition modes allowed resolving a larger number of chemical compounds (specially SMX degradation subproducts) that could not be detected by UV-Vis spectrometry. The results obtained permitted the comparison of the effects produced by the three different degradation processes.
Topics: Sulfamethoxazole; Chemometrics; Halogenation; Photolysis; Chlorine; Spectrophotometry; Mass Spectrometry; Chromatography, Liquid
PubMed: 37573101
DOI: 10.1016/j.aca.2023.341563 -
Molecules (Basel, Switzerland) Dec 2022This study aims to collect information about soil investigation by FTIR. As we know, the FTIR technique is most often used in organic and bioorganic chemistry, while in... (Review)
Review
This study aims to collect information about soil investigation by FTIR. As we know, the FTIR technique is most often used in organic and bioorganic chemistry, while in geochemistry FTIR spectroscopy is not used very often. Therefore, there is a problem with the identification and interpretation of the IR spectra of minerals contained in sediments and soils. The reason for this is a deficiency of data about characteristic wavenumbers for minerals. Therefore, this study reviews and sums up, in one place, published articles that are connected to an investigation of minerals from 2002 to 2021 (based on the Scopus database). Additionally, the present review highlights various analytical techniques (ATR-FTIR, DRIFT, 2D-IR, and SR-FTIR) and discusses some of them for geochemical study. Additionally, the study describes helpful tools in the data pre-processing of IR spectra (normalization, baseline correction, and spectral derivatives).
Topics: Spectroscopy, Fourier Transform Infrared; Spectrophotometry, Infrared; Minerals; Soil
PubMed: 36557982
DOI: 10.3390/molecules27248846 -
PloS One 2022The spectrophotometer has been used for decades to measure the density of bacterial populations as the turbidity expressed as optical density-OD. However, the OD alone...
The spectrophotometer has been used for decades to measure the density of bacterial populations as the turbidity expressed as optical density-OD. However, the OD alone is an unreliable metric and is only proportionately accurate to cell titers to about an OD of 0.1. The relationship between OD and cell titer depends on the configuration of the spectrophotometer, the length of the light path through the culture, the size of the bacterial cells, and the cell culture density. We demonstrate the importance of plate reader calibration to identify the exact relationship between OD and cells/mL. We use four bacterial genera and two sizes of micro-titer plates (96-well and 384-well) to show that the cell/ml per unit OD depends heavily on the bacterial cell size and plate size. We applied our calibration curve to real growth curve data and conclude the cells/mL-rather than OD-is a metric that can be used to directly compare results across experiments, labs, instruments, and species.
Topics: Bacteria; Spectrophotometry
PubMed: 36228033
DOI: 10.1371/journal.pone.0276040