866 results match your criteria spectral deconvolution

Time-Space-Resolved Chemical Deconvolution of Cementitious Colloidal Systems Using Raman Spectroscopy.

Langmuir 2021 Jun 7;37(23):7019-7031. Epub 2021 Jun 7.

Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States.

Concrete is one of the most used materials in the world, second only to water. One of the key advantages of this versatile material is its workability in the early stages before setting. Here, we use underwater Raman microspectroscopy to investigate and visualize the early hydration kinetics of ordinary Portland cement (OPC) with submicron spatial and high temporal resolution. Read More

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Optical property trends in a family of {MoI} aquahydroxo complexes.

Dalton Trans 2021 Jun 7. Epub 2021 Jun 7.

Nikolaev Institute of Inorganic Chemistry SB RAS, 3 Acad. Lavrentiev Ave., 630090 Novosibirsk, Russian Federation.

Luminescence is one of the key properties of octahedral molybdenum cluster complexes and the basis for most areas of their possible practical applications. Nevertheless, the factors affecting the optical properties of the clusters are insufficiently studied and establishing them will allow us to tune both absorption and emission more precisely. In this work, we obtained two new cationic [{Mo6I8}(H2O)4(OH)2](An)2·nH2O (An = NO3-, n = 3; An = OTs-, n = 2, OTs- - p-toluenesulfonate), and two neutral [{Mo6I8}(H2O)2(OH)4]·nH2O (n = 2, 12) aquahydroxo complexes. Read More

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Perturbing the Movement of Hydrogens to Delineate and Assign Events in the Reductive Activation and Turnover of Porcine Dihydropyrimidine Dehydrogenase.

Biochemistry 2021 Jun 25;60(22):1764-1775. Epub 2021 May 25.

Department of Chemistry and Biochemistry, Loyola University Chicago, 1068 West Sheridan Road, Chicago, Illinois 60660, United States.

The native function of dihydropyrimidine dehydrogenase (DPD) is to reduce the 5,6-vinylic bond of pyrimidines uracil and thymine with electrons obtained from NADPH. NADPH and pyrimidines bind at separate active sites separated by ∼60 Å that are bridged by four FeS centers. We have shown that DPD undergoes reductive activation, taking up two electrons from NADPH [Beaupre, B. Read More

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Novel acquisition strategies for metabolomics using drift tube ion mobility-quadrupole resolved all ions time-of-flight mass spectrometry (IM-QRAI-TOFMS).

Anal Chim Acta 2021 Jun 12;1163:338508. Epub 2021 Apr 12.

Institute of Analytical Chemistry, Department of Chemistry, University of Natural Resources and Life Sciences, Vienna (BOKU), Muthgasse 18, 1190 Vienna, Austria. Electronic address:

The focus of this work was the implementation of ion mobility (IM) and a prototype quadrupole driver within data independent acquisition (DIA) using a drift tube IM-QTOFMS aiming to improve the level of confidence in identity confirmation workflows for non-targeted metabolomics. In addition to conventional all ions (IM-AI) acquisition, quadrupole resolved all ions (IM-QRAI) acquisition allows a drift time-directed precursor ion isolation in DIA using sequential isolation of precursor ions using mass windows of up to 100 Da which can be rapidly ramped across single ion mobility transients (i.e. Read More

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High-resolution H NMR profiling of triacylglycerols as a tool for authentication of food from animal origin: Application to hen egg matrix.

Food Chem 2021 Oct 11;360:130056. Epub 2021 May 11.

Laboratory of Metrology and Isotopic Fractionation, Research Unit: Technologies et Valorisation Agroalimentaire (TVA), Faculty of Science, Saint Joseph University of Beirut, P.O. Box 17-5208 Mar Mikhael, Beirut 1104 2020, Lebanon. Electronic address:

Metabolomics of complex biological matrices conducted by means of H NMR leads to spectra suffering from severe signal overlapping. Previously, we have developed a high-resolution spectral treatment method to help solving this issue in H NMR of triacylglycerols. In this work, we tested the potential of the developed method in the characterization and authentication of food products from animal origin using egg yolk as a model matrix. Read More

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October 2021

Depth estimates of anomalous subsurface sources using 2D/3D modeling of potential field data: implications for groundwater dynamics in the Ziway-Shala Lakes Basin, Central Main Ethiopian Rift.

Heliyon 2021 Apr 20;7(4):e06843. Epub 2021 Apr 20.

Addis Ababa University Institute of Geophysics, Space Science and Astronomy (IGSSA), Ethiopia.

Quantitative analysis of potential field data are made in the Ziway-Shala lakes basin over an area bounded by 3800' E - 3930' E and 700' N - 830' N. Most previous geophysical studies in the region under consideration focus on mapping the deep crustal structures and undulation of the Moho depth. Only few studies are targeted at mapping the shallow subsurface structures. Read More

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Role of hydrogen bond alternation and charge transfer states in photoactivation of the Orange Carotenoid Protein.

Commun Biol 2021 May 10;4(1):539. Epub 2021 May 10.

Faculty of Biology, M.V. Lomonosov Moscow State University, Moscow, Russia.

Here, we propose a possible photoactivation mechanism of a 35-kDa blue light-triggered photoreceptor, the Orange Carotenoid Protein (OCP), suggesting that the reaction involves the transient formation of a protonated ketocarotenoid (oxocarbenium cation) state. Taking advantage of engineering an OCP variant carrying the Y201W mutation, which shows superior spectroscopic and structural properties, it is shown that the presence of Trp201 augments the impact of one critical H-bond between the ketocarotenoid and the protein. This confers an unprecedented homogeneity of the dark-adapted OCP state and substantially increases the yield of the excited photoproduct S*, which is important for the productive photocycle to proceed. Read More

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Advanced eco-friendly UV spectrophotometric approach for resolving overlapped spectral signals of antihypertensive agents in their binary and tertiary pharmaceutical dosage form.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Sep 19;258:119855. Epub 2021 Apr 19.

Pharmaceutical Chemistry Department, Faculty of Pharmacy, Egyptian Russian University, Badr City 11829, Cairo, Egypt. Electronic address:

Cardiovascular disorders are among the foremost causes of death worldwide, especially hypertension, a silent killer syndrome that requires multiple drug therapy for proper management. This work presents novel and green spectrophotometric methods for the concurrent analysis of Amlodipine (AML), Telmisartan (TEL), Hydrochlorothiazide (HCTZ), and Chlorthalidone (CLO) in their pharmaceutical dosage form. The suggested methods were Fourier-self deconvolution, amplitude factor, and first derivative methods developed and validated for the simultaneous determination of a tertiary mixture of AML, TEL, and HCTZ in TELVAS 3D 80 mg tablet and a binary mixture of TEL and CLO in TELMIKIND-CT 40 tablets. Read More

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September 2021

Data Processing Optimization in Untargeted Metabolomics of Urine Using Voigt Lineshape Model Non-Linear Regression Analysis.

Metabolites 2021 Apr 29;11(5). Epub 2021 Apr 29.

Research Unit Analytical BioGeoChemistry, Helmholtz Zentrum München, German Research Center for Environmental Health, D-85764 Neuherberg, Germany.

Nuclear magnetic resonance (NMR) spectroscopy is well-established to address questions in large-scale untargeted metabolomics. Although several approaches in data processing and analysis are available, significant issues remain. NMR spectroscopy of urine generates information-rich but complex spectra in which signals often overlap. Read More

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Technical Note: Post-burial alteration of bones: Quantitative characterization with solid-state H MAS NMR.

Forensic Sci Int 2021 Apr 10;323:110783. Epub 2021 Apr 10.

National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia.

The identification of markers of the modifications occurring in human bones after death and of the sedimentary and post-sedimentary processes affecting their state of preservation, is of interest for several scientific disciplines. A new index, obtained from spectral deconvolution of the H MAS NMR spectra of bones, relating the number of organic protons to the amount of hydrogen nuclei in the OH groups of bioapatite, is proposed as indicator of the state of preservation of the organic fraction. In the osteological material from three different archaeological sites, this index resulted positively correlated with the extent of collagen loss derived from infrared spectroscopy. Read More

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Time-dependent surface modification of uranium oxides exposed to water plasma.

Dalton Trans 2021 Apr 19;50(14):4796-4804. Epub 2021 Mar 19.

School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Department of Chemistry, Applied Physical Chemistry, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden.

Thin UO films exposed to water plasma under UHV conditions have been shown to be interesting models for radiation induced oxidative dissolution of spent nuclear fuel. This is partly attributed to the fact that several of the reactive oxidizing and reducing species in a water plasma are also identified as products of radiolysis of water. Exposure of UO films to water plasma has previously been shown to lead to oxidation from U(iv) to U(v) and (vi). Read More

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Spotting isomer mixtures in forensic illicit drug casework with GC-VUV using automated coelution detection and spectral deconvolution.

J Chromatogr B Analyt Technol Biomed Life Sci 2021 Mar 29;1173:122675. Epub 2021 Mar 29.

Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, PO Box 94157, Amsterdam 1090 GD, the Netherlands; Co van Ledden Hulsebosch Center (CLHC), Amsterdam Center for Forensic Science and Medicine, PO Box 94157, Amsterdam 1090 GD, the Netherlands.

Analysis of isomeric mixtures is a significant analytical challenge. In the forensic field, for example, over 1000 new psychoactive substances (NPSs), comprising of many closely related and often isomeric varieties, entered the drugs-of-abuse market within the last decade. Unambiguous identification of the isomeric form requires advanced spectroscopic techniques, such as GC-Vacuum Ultraviolet Spectroscopy (GC-VUV). Read More

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Spectral analysis of severely overlapping spectra based on newly developed mathematical filtration techniques and ratio spectra manipulations: An application to the concurrent determination of dapoxetine and sildenafil in combined dosage form.

Spectrochim Acta A Mol Biomol Spectrosc 2021 Jul 19;255:119715. Epub 2021 Mar 19.

Pharmaceutical Chemistry Department, Faculty of Pharmacy, Egyptian Russian University, Badr City, Cairo 11829, Egypt. Electronic address:

Background: Dapoxetine hydrochloride (DAP) and sildenafil citrate (SIL) have proven clinically effective in the treatment of comorbid conditions like erectile dysfunction and premature ejaculation. The analysis of DAP and SIL combinations represents a challenge because of the severe overlap of these compounds' spectra. Six newly developed methods were proven effective for resolving such a challenging overlap. Read More

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Masked Multiplexed Separations to Enhance Duty Cycle for Structures for Lossless Ion Manipulations.

Anal Chem 2021 04 2;93(14):5727-5734. Epub 2021 Apr 2.

MOBILion Systems Inc., Chadds Ford, Pennsylvania 19317, United States.

The experimental paradigm of one ion packet release per spectrum severely hinders throughput in broadband ion mobility spectrometry (IMS) systems (e.g., drift tube and traveling wave systems). Read More

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Probing Heme Active Sites of Hemoglobin in Functional Red Blood Cells Using Resonance Raman Spectroscopy.

J Phys Chem B 2021 04 31;125(14):3556-3565. Epub 2021 Mar 31.

Chemistry Department, Saint Louis University, 3501 Laclede Avenue, Saint Louis 63103, Missouri, United States.

The UV-vis absorption, Raman imaging, and resonance Raman (rR) spectroscopy methods were employed to study cyanohemoglobin (HbCN) adducts inside living functional red blood cells (RBCs). The cyanide ligands are especially optically sensitive probes of the active site environment of heme proteins. The rR studies of HbCN and its isotopic analogues (CN, CN, and CN), as well as a careful deconvolution of spectral data, revealed that the ν(Fe-CN) stretching, δ(Fe-CN) bending, and ν(C≡N) stretching modes occur at 454, 382, and 2123 cm, respectively. Read More

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TopMSV: A Web-Based Tool for Top-Down Mass Spectrometry Data Visualization.

J Am Soc Mass Spectrom 2021 Jun 29;32(6):1312-1318. Epub 2021 Mar 29.

Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana 46202, United States.

Top-down mass spectrometry (MS) investigates intact proteoforms for proteoform identification, characterization, and quantification. Data visualization plays an essential role in top-down MS data analysis because proteoform identification and characterization often involve manual data inspection to determine the molecular masses of highly charged ions and validate unexpected alterations in identified proteoforms. While many software tools have been developed for MS data visualization, there is still a lack of web-based visualization software designed for top-down MS. Read More

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Investigation of Cyanide Ligand as an Active Site Probe of Human Heme Oxygenase.

Inorg Chem 2021 Apr 23;60(7):4633-4645. Epub 2021 Mar 23.

Chemistry Department, Saint Louis University, Saint Louis, Missouri 63103, United States.

Human heme oxygenase (hHO-1) is a physiologically important enzyme responsible for free heme catabolism. The enzyme's high regiospecificity is controlled by the distal site hydrogen bond network that involves water molecules and the D140 amino acid residue. In this work, we probe the active site environment of the wild-type (WT) hHO-1 and its D140 mutants using resonance Raman (rR) spectroscopy. Read More

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A Computationally Lightweight Algorithm for Deriving Reliable Metabolite Panel Measurements from 1D H NMR.

Anal Chem 2021 03 18;93(12):4995-5000. Epub 2021 Mar 18.

National Phenome Centre, Imperial College London, Hammer-smith Campus, IRDB Building, London W12 0NN, United Kingdom.

Small Molecule Enhancement SpectroscopY (SMolESY) was employed to develop a unique and fully automated computational solution for the assignment and integration of H nuclear magnetic resonance (NMR) signals from metabolites in challenging matrices containing macromolecules (herein blood products). Sensitive and reliable quantitation is provided by instant signal deconvolution and straightforward integration bolstered by spectral resolution enhancement and macromolecular signal suppression. The approach is highly efficient, requiring only standard one-dimensional H NMR spectra and avoiding the need for sample preprocessing, complex deconvolution, and spectral baseline fitting. Read More

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Role of Ions on the Surface-Bound Water Structure at the Silica/Water Interface: Identifying the Spectral Signature of Stability.

J Phys Chem Lett 2021 Mar 15;12(11):2854-2864. Epub 2021 Mar 15.

Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada.

Isolating the hydrogen-bonding structure of water immediately at the surface is challenging, even with surface-specific techniques like sum-frequency generation (SFG), because of the presence of aligned water further away in the diffuse layer. Here, we combine zeta potential and SFG intensity measurements with the maximum entropy method referenced to reported phase-sensitive SFG and second-harmonic generation results to deconvolute the SFG spectral contributions of the surface waters from those in the diffuse layer. Deconvolution reveals that at very low ionic strength, the surface water structure is similar to that of a neutral silica surface near the point-of-zero-charge with waters in different hydrogen-bonding environments oriented in opposite directions. Read More

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Systematic stability testing of insulins as representative biopharmaceuticals using ATR FTIR-spectroscopy with focus on quality assurance.

J Biomed Opt 2021 Mar;26(4)

South-Westphalia University of Applied Sciences, Interdisciplinary Center for Life Sciences, Iserloh, Germany.

Significance: Bioactive proteins represent the most important component class in biopharmaceutical products for therapeutic applications. Their production is most often biotechnologically realized by genetically engineered microorganisms. For the quality assurance of insulins as representatives of life-saving pharmaceuticals, analytical methods are required that allow more than total protein quantification in vials or batches. Read More

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Comparison of methodologies used to determine aromatic lignin unit ratios in lignocellulosic biomass.

Biotechnol Biofuels 2021 Mar 6;14(1):58. Epub 2021 Mar 6.

Renewable Resources and Enabling Sciences Center, National Renewable Energy Laboratory, Golden, CO, 80401, USA.

Background: Multiple analytical methods have been developed to determine the ratios of aromatic lignin units, particularly the syringyl/guaiacyl (S/G) ratio, of lignin biopolymers in plant cell walls. Chemical degradation methods such as thioacidolysis produce aromatic lignin units that are released from certain linkages and may induce chemical changes rendering it difficult to distinguish and determine the source of specific aromatic lignin units released, as is the case with nitrobenzene oxidation methodology. NMR methods provide powerful tools used to analyze cell walls for lignin composition and linkage information. Read More

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Super-resolution Microscopy-based Bimolecular Fluorescence Complementation to Study Protein Complex Assembly and Co-localization.

Bio Protoc 2020 Feb 20;10(4):e3524. Epub 2020 Feb 20.

Stowers Institute for Medical Research, Kansas City, MO 64110, USA.

Numerous experimental approaches exist to study interactions between two subunits of a large macromolecular complex. However, most methods do not provide spatial and temporal information about binding, which are critical for dissecting the mechanism of assembly of nanosized complexes . While recent advances in super-resolution microscopy techniques have provided insights into biological structures beyond the diffraction limit, most require extensive expertise and/or special sample preparation, and it is a challenge to extend beyond binary, two color experiments. Read More

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February 2020

New global aerosol fine-mode fraction data over land derived from MODIS satellite retrievals.

Environ Pollut 2021 May 8;276:116707. Epub 2021 Feb 8.

Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park, MD, 20740, USA. Electronic address:

The space-borne measured fine-mode aerosol optical depth (fAOD) is a gross index of column-integrated anthropogenic particulate pollutants, especially over the populated land. The fAOD is the product of the AOD and the fine-mode fraction (FMF). While there exist numerous global AOD products derived from many different satellite sensors, there have been much fewer, if any, global FMF products with a quality good enough to understand their spatiotemporal variations. Read More

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Improving Spectral Validation Rates in Hydrogen-Deuterium Exchange Data Analysis.

Anal Chem 2021 03 16;93(9):4246-4254. Epub 2021 Feb 16.

Department of Chemistry, University of Calgary, Calgary, Alberta, Canada T2N-4N1.

The data analysis practices associated with hydrogen-deuterium exchange mass spectrometry (HX-MS) lag far behind that of most other MS-based protein analysis tools. A reliance on external tools from other fields and a persistent need for manual data validation restrict this powerful technology to the expert user. Here, we provide an extensive upgrade to the HX data analysis suite available in the Mass Spec Studio in the form of two new apps (HX-PIPE and HX-DEAL), completing a workflow that provides an HX-tailored peptide identification capability, accelerated validation routines, automated spectral deconvolution strategies, and a rich set of exportable graphics and statistical reports. Read More

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Spectral deconvolution of redox species in the crotonyl-CoA-dependent NADH:ferredoxin oxidoreductase from Megasphaera elsdenii. A flavin-dependent bifurcating enzyme.

Arch Biochem Biophys 2021 04 12;701:108793. Epub 2021 Feb 12.

Department of Biochemistry, University of California, Riverside, Riverside, CA, 92521, USA. Electronic address:

We have undertaken a spectral deconvolution of the three FADs of EtfAB/bcd to the spectral changes seen in the course of reduction, including the spectrally distinct anionic and neutral semiquinone states of electron-transferring and bcd flavins. We also demonstrate that, unlike similar systems, no charge-transfer complex is observed on titration of the reduced M. elsdenii EtfAB with NAD. Read More

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NMF-Based Spectral Deconvolution with a Web Platform GC Mixture Touch.

Yasuyuki Zushi

ACS Omega 2021 Feb 19;6(4):2742-2748. Epub 2021 Jan 19.

Research Institute of Science for Safety and Sustainability, National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaragi 305-8506, Japan.

Complete separation of chemicals in a complex mixture is far from being achieved even with the current high-performance separation technology, such as gas chromatography-mass spectrometry (GC-MS). Several deconvolution techniques based on multivariate curve resolution (MCR), or model peak methods, which are represented by AMDIS, have been developed to address the above-mentioned issue. The model peak methods have been developed to provide easy-to-use tools, including AMDIS, but are limited for MCR with approximation methods. Read More

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February 2021

Experimental and computational data on two-photon absorption and spectral deconvolution of the upper excited states of dye IR780.

Data Brief 2021 Apr 15;35:106752. Epub 2021 Jan 15.

Departamento de Física, Universidad Autónoma Metropolitana Iztapalapa, Av. San Rafael Atlixco No. 186 Col. Vicentina, C.P. 09340 México D.F., México.

Evaluating candidates for novel materials with high nonlinear absorption properties for applications as biomarkers is a very important field of research. In this context, experimental and computational information on the two-photon absorption (TPA) properties of the dye IR780 is shown. The two-photon absorption data from 850 to 1000 nm for IR780 and other two well-known dyes, taken as reference, are presented. Read More

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Raman spectroscopic detection of polyene-length distribution for high-sensitivity monitoring of photo- and thermal degradation of polyvinylchloride.

Spectrochim Acta A Mol Biomol Spectrosc 2021 May 22;252:119494. Epub 2021 Jan 22.

Physics and Earth Sciences, Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany. Electronic address:

The degradation of the ubiquitous polyvinylchloride (PVC) material under the influence of various factors is known to result commonly in polyene formation. Such polyene defects occur in the form of conjugated aliphatic chains with different lengths and contents, and their sensitive and length-specific monitoring is important for the assessment of PVC degradation. Here, we report on the resonance-enhanced Raman signatures of polyene sequences of varying lengths in photo- and thermally degraded PVC films. Read More

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PCA denoising and Wiener deconvolution of P 3D CSI data to enhance effective SNR and improve point spread function.

Magn Reson Med 2021 06 1;85(6):2992-3009. Epub 2021 Feb 1.

Department of Radiology, Imaging Division, University Medical Center Utrecht, Utrecht, The Netherlands.

Purpose: This study evaluates the performance of 2 processing methods, that is, principal component analysis-based denoising and Wiener deconvolution, to enhance the quality of phosphorus 3D chemical shift imaging data.

Methods: Principal component analysis-based denoising increases the SNR while maintaining spectral information. Wiener deconvolution reduces the FWHM of the voxel point spread function, which is increased by Hamming filtering or Hamming-weighted acquisition. Read More

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Ras-guanine nucleotide complexes: A UV spectral deconvolution method to analyze protein concentration, nucleotide stoichiometry, and purity.

Anal Biochem 2021 04 22;618:114066. Epub 2021 Jan 22.

Molecular Biophysics Program and Department of Biochemistry, University of Colorado, Boulder, CO, 80309-0596, United States. Electronic address:

The many members of the Ras superfamily are small GTPases that serve as molecular switches. These proteins bind the guanine nucleotides GTP and GDP with picomolar affinities, thereby stabilizing on- and off-signaling states, respectively. Quantitative in vitro Ras studies require accurate determination of total protein, its fractional occupancy with guanine nucleotide, and spectroscopic purity. Read More

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