jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: C. M. Raghavan | Mohammed Thofike Ahmed Choudhury | Aleksey Rozhin
Source: Food Chemistry (article, 2023-03-06)
Field: Chemistry — Analytical Chemistry

2D excitation-emission fluorescence mapping analysis of plant food pigments Homogeneous dispersion of plant food pigments is indispensable to study their characteristic fluorescence features for non-destructive rapid monitoring of food systems. However, it is highly challenging to obtain such optical grade homogenized stable dispersion of various plant pigments in aqueous media for tracing their precise fluorescence signatures. Herein, we demonstrate a unique strategy to disperse various pigments, such as chlorophylls, carotenoids and phenolic compounds by the high-speed shear-force mixing of fresh green and red bell peppers (Capsicum annuum) in an aqueous medium with followed centrifugation and filtration. An advanced FLuorescence Excitation-emission (FLE) mapping and optical absorption analysis from the optical grade aqueous bell peppers dispersion allow simultaneous probing of chlorophylls, phenolic compounds and carotenoids by their characteristic electronic transitions. The demonstrated sampling protocols and spectroscopic analysis will be highly beneficial to obtain advanced spectroscopic databases from different food materials for rapid food analysis and quality control. Fluorescence ; Pigment ; Chemistry ; Aqueous solution ; Dispersion (optics) ; Analytical Chemistry (journal) ; Centrifugation ; Chromatography ; Optics ; Organic chemistry ; Physics Dye analysis and toxicity ; Electrochemical Analysis and Applications ; Spectroscopy and Chemometric Analyses
Authors: Laura Carlini | F. Montorsi | Yingxuan Wu | P. Bolognesi | Rocío Borrego‐Varillas | A. Casavola | Mattea Carmen Castrovilli | Jacopo Chiarinelli | D. Mocci | Federico Vismarra | Matteo Lucchini | M. Nisoli | Shaul Mukamel | Marco Garavelli | Robert Richter | Artur Nenov | L. Avaldi
Source: The Journal of Chemical Physics (article, 2023-01-17)
Field: Materials Science — Materials Chemistry

Electron and ion spectroscopy of azobenzene in the valence and core shells Azobenzene is a prototype and a building block of a class of molecules of extreme technological interest as molecular photo-switches. We present a joint experimental and theoretical study of its response to irradiation with light across the UV to x-ray spectrum. The study of valence and inner shell photo-ionization and excitation processes combined with measurement of valence photoelectron-photoion coincidence and mass spectra across the core thresholds provides a detailed insight into the site- and state-selected photo-induced processes. Photo-ionization and excitation measurements are interpreted via the multi-configurational restricted active space self-consistent field method corrected by second order perturbation theory. Using static modeling, we demonstrate that the carbon and nitrogen K edges of azobenzene are suitable candidates for exploring its photoinduced dynamics thanks to the transient signals appearing in background-free regions of the NEXAFS and XPS. Azobenzene ; Valence (chemistry) ; Ionization ; X-ray photoelectron spectroscopy ; Ion ; Spectroscopy ; Atomic physics ; Excitation ; Valence electron ; Molecular physics ; Chemistry ; Materials science ; Molecule ; Electron ; Physics ; Nuclear magnetic resonance Photochromic and Fluorescence Chemistry ; Photoreceptor and optogenetics research ; Photochemistry and Electron Transfer Studies
Authors: Nuwandi M. Ariyasingha | Anna Samoilenko | Jonathan R. Birchall | Md Raduanul H. Chowdhury | Oleg G. Salnikov | Larisa M. Kovtunova | V. I. Bukhtiyarov | David C. Zhu | Chunqi Qian | M. Scott Bradley | Juri G. Gelovani | Igor V. Koptyug | Boyd M. Goodson | Eduard Y. Chekmenev
Source: ACS Sensors (article, 2023-09-29)
Field: Chemistry — Spectroscopy

Ultra-Low-Cost Disposable Hand-Held Clinical-Scale Propane Gas Hyperpolarizer for Pulmonary Magnetic Resonance Imaging Sensing Hyperpolarized magnetic resonance imaging (MRI) contrast agents are revolutionizing the field of biomedical imaging. Hyperpolarized Xe-129 was recently FDA approved as an inhalable MRI contrast agent for functional lung imaging sensing. Despite success in research settings, modern Xe-129 hyperpolarizers are expensive (up to $1M), large, and complex to site and operate. Moreover, Xe-129 sensing requires specialized MRI hardware that is not commonly available on clinical MRI scanners. Here, we demonstrate that proton-hyperpolarized propane gas can be produced on demand using a disposable, hand-held, clinical-scale hyperpolarizer via parahydrogen-induced polarization, which relies on parahydrogen as a source of hyperpolarization. The device consists of a heterogeneous catalytic reactor connected to a gas mixture storage can containing pressurized hyperpolarization precursors: propylene and parahydrogen (10 bar total pressure). Once the built-in flow valve of the storage can is actuated, the precursors are ejected from the can into a reactor, and a stream of hyperpolarized propane gas is ejected from the reactor. Robust operation of the device is demonstrated for producing proton sensing polarization of 1.2% in a wide range of operational pressures and gas flow rates. We demonstrate that the propylene/parahydrogen gas mixture can retain potency for days in the storage can with a monoexponential decay time constant of 6.0 ± 0.5 days, which is limited by the lifetime of the parahydrogen singlet spin state in the storage container. The utility of the produced sensing agent is demonstrated for phantom imaging on a 3 T clinical MRI scanner located 100 miles from the agent/device preparation site and also for ventilation imaging of excised pig lungs using a 0.35 T clinical MRI scanner. The cost of the device components is less than $35, which we envision can be reduced to less than $5 for mass-scale production. The hyperpolarizer device can be reused, recycled, or disposed. Spin isomers of hydrogen ; Hyperpolarization (physics) ; Propane ; Magnetic resonance imaging ; Scanner ; Induced polarization ; Nuclear magnetic resonance ; Imaging phantom ; Chemistry ; Materials science ; Hydrogen ; Optics ; Nuclear magnetic resonance spectroscopy ; Electrical engineering Advanced NMR Techniques and Applications ; Atomic and Subatomic Physics Research ; Solid-state spectroscopy and crystallography
Authors: Noriki Terada | Hiroaki Mamiya | Hiraku Saito | Taro Nakajima | Takafumi D. Yamamoto | Kensei Terashima | Hiroyuki Takeya | Osamu Sakai | Shinichi Itoh | Yoshihiko Takano | Masashi Hase | Hideaki Kitazawa
Source: Communications Materials (article, 2023-02-15)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Crystal electric field level scheme leading to giant magnetocaloric effect for hydrogen liquefaction Abstract In recent years, magnetic refrigeration has attracted considerable attention for hydrogen liquefaction. Most materials used for magnetic refrigeration contain heavy rare earth ions with complex crystalline electric field energy splittings, whose effect on the magnetic entropy change Δ S M has not been systematically studied. In particular, the theoretical upper limits of ∣Δ S M ∣ for general heavy earth cases are unknown. Here, we show that the crystalline electric field level schemes result in a large Δ S M for general heavy rare earth cases. We provide a specific example of the magnetic refrigeration material HoB 2 using inelastic neutron scattering experiments combined with mean-field calculations with crystal field splitting and exchange interactions. The relationship between Δ S M and crystal field parameters presented in this study can be useful for developing compounds with a large ∣Δ S M ∣ and advancing the design of magnetic refrigeration materials. Magnetic refrigeration ; Liquefaction ; Electric field ; Refrigeration ; Magnetic field ; Inelastic neutron scattering ; Condensed matter physics ; Magnetization ; Hydrogen ; Materials science ; Ion ; Hydrogen storage ; Neutron ; Physics ; Neutron scattering ; Thermodynamics ; Nuclear physics Magnetic and transport properties of perovskites and related materials ; Rare-earth and actinide compounds ; Advanced Condensed Matter Physics
Authors: Muhammad Asif | Qiong Wang | Zhengbiao Ouyang | Mi Lin | Zixian Liang
Source: Crystals (article, 2023-12-25)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Ultra-Wideband Terahertz Wave Absorber Using Vertically Structured IGIGIM Metasurface Achieving perfect absorption of electromagnetic waves across a wide range of frequencies is crucial for various applications, including sensing, imaging, and energy capture. In this study, we introduced a new concept for metasurfaces and proposed a six-layer vertically structured IGIGIM metasurface consisting of gold (Au), silicon (Si), graphene (G1), silica (SiO2), a second layer of graphene (G2), and polymethyl methacrylate (PMMA), which demonstrates ultra-wideband absorptance in the terahertz (THz) region. Through theoretical analysis and numerical simulations, we obtained broadband absorptance over 80% with the average absorptance of 92.6% and a bandwidth of 8.22 THz, from 1.78 to 10.0 THz. Whereas, dual broadband absorptance was obtained for above 90% with the bandwidth of 5.63 THz in the two sub-bands of 2.09–3.5 THz and 5.78–10 THz and above 95% with the bandwidth of 3.63 THz in the two sub-bands of 2.32–3.12 THz and 6.35–9.9 THz. Moreover, the proposed structure exhibits a polarization-independent absorption property. Also, it demonstrates a tolerance for the incident angle of 40 degrees, maintaining a wide absorption band. This remarkable feature is attributed to the multiple Fabry–Pérot resonance absorptions in the structure. Our study presents a convenient method for designing high-quality terahertz wave absorbers with outstanding broadband absorptance. Terahertz radiation ; Absorptance ; Materials science ; Optoelectronics ; Broadband ; Wideband ; Optics ; Bandwidth (computing) ; Absorption (acoustics) ; Graphene ; Electromagnetic radiation ; Physics ; Reflectivity ; Nanotechnology ; Telecommunications Metamaterials and Metasurfaces Applications ; Advanced Antenna and Metasurface Technologies ; Antenna Design and Analysis
Authors: Benjamin Yang | Forwood Wiser | V. Faye McNeill | Arlene M. Fiore | Madankui Tao | Daven K. Henze | Siddhartha Sen | Daniel M. Westervelt
Source: Environmental Science Atmospheres (article, 2023-01-01)
Field: Materials Science — Materials Chemistry

Implementation and evaluation of the automated model reduction (AMORE) version 1.1 isoprene oxidation mechanism in GEOS-Chem A chemical transport model with a graph theory-based isoprene oxidation mechanism is used to simulate ozone and fine particulate matter distributions needed to quantify health and climate impacts. Isoprene ; Mechanism (biology) ; Particulates ; Ozone ; Reduction (mathematics) ; Reaction mechanism ; Environmental science ; Chemistry ; Biochemical engineering ; Environmental chemistry ; Organic chemistry ; Physics ; Mathematics ; Catalysis ; Engineering ; Polymer Machine Learning in Materials Science ; Analytical Chemistry and Chromatography ; Computational Drug Discovery Methods
Authors: Henry Webel | Lili Niu | Annelaura Bach Nielsen | Marie Locard‐Paulet | Matthias Mann | Lars Juhl Jensen | Simon Rasmussen
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-01-13)
Field: Chemistry — Spectroscopy

Imputation of label-free quantitative mass spectrometry-based proteomics data using self-supervised deep learning Abstract Imputation techniques provide means to replace missing measurements with a value and are used in almost all downstream analysis of mass spectrometry (MS) based proteomics data using label-free quantification (LFQ). Here we demonstrate how collaborative filtering, denoising autoencoders, and variational autoencoders can impute missing values in the context of LFQ at different levels. We applied our method, proteomics imputation modeling mass spectrometry (PIMMS), to an alcohol-related liver disease (ALD) cohort with blood plasma proteomics data available for 358 individuals. Removing 20 percent of the intensities we were able to recover 15 out of 17 significant abundant protein groups using PIMMS-VAE imputations. When analyzing the full dataset we identified 30 additional proteins (+13.2%) that were significantly differentially abundant across disease stages compared to no imputation and found that some of these were predictive of ALD progression in machine learning models. We, therefore, suggest the use of deep learning approaches for imputing missing values in MS-based proteomics on larger datasets and provide workflows for these. Imputation (statistics) ; Missing data ; Proteomics ; Computer science ; Label-free quantification ; Artificial intelligence ; Mass spectrometry ; Quantitative proteomics ; Machine learning ; Chromatography ; Chemistry Advanced Proteomics Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Mass Spectrometry Techniques and Applications
Authors: Bikash Kanungo | Jeffrey Hatch | Paul M. Zimmerman | Vikram Gavini
Source: The Journal of Physical Chemistry Letters (article, 2023-11-01)
Field: Chemistry — Spectroscopy

Exact and Model Exchange-Correlation Potentials for Open-Shell Systems The conventional approaches to the inverse density functional theory problem typically assume nondegeneracy of the Kohn-Sham (KS) eigenvalues, greatly hindering their use in open-shell systems. We present a generalization of the inverse density functional theory problem that can seamlessly admit degenerate KS eigenvalues. Additionally, we allow for fractional occupancy of the Kohn-Sham orbitals to also handle noninteracting ensemble-v-representable densities, as opposed to just noninteracting pure-v-representable densities. We present the exact exchange-correlation (XC) potentials for six open-shell systems─four atoms (Li, C, N, and O) and two molecules (CN and CH<sub>2</sub>)─using accurate ground-state densities from configuration interaction calculations. We compare these exact XC potentials with model XC potentials obtained using nonlocal (B3LYP, SCAN0) and local/semilocal (SCAN, PBE, PW92) XC functionals. Although the relative errors in the densities obtained from these DFT functionals are of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>O</mml:mi></mml:math>(10<sup>-3</sup> to 10<sup>-2</sup>), the relative errors in the model XC potentials remain substantially large─<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>O</mml:mi></mml:math>(10<sup>-1</sup> to 10<sup>0</sup>). Open shell ; Degenerate energy levels ; Eigenvalues and eigenvectors ; Generalization ; Density functional theory ; Kohn–Sham equations ; Atomic orbital ; Inverse ; Physics ; Shell (structure) ; Quantum mechanics ; Statistical physics ; Molecular physics ; Computational chemistry ; Mathematics ; Mathematical analysis ; Chemistry ; Materials science ; Geometry Advanced NMR Techniques and Applications ; Solid-state spectroscopy and crystallography ; Advanced Chemical Physics Studies
Authors: Eman M. Morgan | Shereen A. Boltia | Yasmin M. Fayez | M. A. Abdelkawy | Hayam M. Lotfy
Source: Heliyon (article, 2023-05-18)
Field: Chemistry — Analytical Chemistry

Coupling of physical extraction and mathematical filtration in spectrophotometric analysis of natural therapy essential for prophylaxis and treatment of COVID-19 infection - Comparative study along with greenness evaluation Diosmin (DIO) and hesperidin (HSP) are important classes of flavonoid glycoside effectively used to prevent comorbid diseases that are commonly associated with COVID-19. An innovative, green, ccurate, effective, cost, and timeless spectrophotometric strategy was established to analyze such challengeable mixture in a co-formulated tablet namely Diosed C® tablets that comprises DIO, HSP and vitamin C (VIT. C) in the ratio of (450 mg: 50 mg: 100 mg) necessary for prevention and treatment of COVID-19. Vitamin C was resolved through physical extraction using de-ionized water while DIO and HSP were extracted via spectrophotometric methods using two different solvents [0.1 M NaOH or solvent blend consisting of DMSO and methanol (1:1)]. Mathematical filtration technique is successfully applied to recover the parent spectra of both DIO and HSP via three methods which are absorbance resolution (AR), Induced absorbance resolution (IAR) and ratio extraction (RE). VIT. C was successfully analyzed in de-ionized water using its maxima at 266.0 nm in a linearity range 2.0-20.0 μg/mL, DIO was effectively determined in 0.1 M NaOH at 372.0 nm in a linearity range of 7.0-70.0 μg/mL as well as in solvent blend at 344.0 nm in linearity range of 5.0-55.0 μg/mL while HSP was accurately analyzed in 0.1 M NaOH at 240.0 nm in linearity range of 3.5-50.0 μg/mL as well as in solvent blend at 285.0 nm in linearity range of 4.0-50.0 μg/mL. Satisfactory results were accomplished when conducting ICH guidelines for assuring the methods validation. Comparative study was introduced in the analysis of such critical combination and was prosperously devoted for the effective analysis of pharmaceutical dosage form. The proposed extraction pathways undergo the guidelines of green analytical chemistry using Analytical Eco-Scale (AES), AGREE and GAPI greenness assessment tools which confirmed their eco-friendly nature with priority to 0.1 M NaOH. The obtained results of the suggested methods were set side by side with those of official/reported methods statistically and show satisfactory implications. The presented methods were simple, affordable, smoothly applicable and their results were acceptable that enhances their usage and application in the quality control laboratories. Coronavirus disease 2019 (COVID-19) ; Extraction (chemistry) ; Medicine ; Filtration (mathematics) ; Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ; 2019-20 coronavirus outbreak ; Intensive care medicine ; Virology ; Chromatography ; Internal medicine ; Chemistry ; Infectious disease (medical specialty) ; Mathematics ; Statistics ; Disease Analytical Methods in Pharmaceuticals ; Medicinal Plants and Neuroprotection ; Psidium guajava Extracts and Applications
Authors: Yalei Fu | Rui Zhang | Jiangnan Xia | A.L. Gough | Stuart Clark | Abhishek Upadhyay | Godwin Enemali | Ian Armstrong | Ihab Ahmed | Mohamed Pourkashanian | Paul Wright | Krikor Ozanyan | Michael Lengden | Walter Johnstone | Nick Polydorides | H. McCann | Chang Liu
Source: IEEE Transactions on Instrumentation and Measurement (article, 2023-01-01)
Field: Chemistry — Spectroscopy

Hybrid Model-Driven Spectroscopic Network for Rapid Retrieval of Turbine Exhaust Temperature Exhaust Gas Temperature (EGT) is a key parameter in diagnosing the health of gas turbine engines (GTEs). In this paper, we propose a model-driven spectroscopic network with strong generalizability to monitor the EGT rapidly and accurately. The proposed network relies on data obtained from a well-proven temperature measurement technique, i.e., wavelength modulation spectroscopy, with the novelty of introducing underlying physical absorption model and building a hybrid dataset from simulation and experiment. This hybrid model-driven network enables strong noise resistance of the neural network against real-world experimental data. The proposed network is assessed by <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in situ</i> measurements of EGT on an aero-GTE at millisecond-level temporal response. Experimental results indicate that the proposed network substantially outperforms previous neural-network methods in terms of accuracy and precision of the measured EGT when the GTE is steadily loaded. Artificial neural network ; Noise (video) ; Millisecond ; Temperature measurement ; Computer science ; Isothermal process ; Artificial intelligence ; Physics Spectroscopy and Laser Applications ; Advanced Combustion Engine Technologies ; Combustion and flame dynamics
Authors: Ying Liu | Pan Gao | Shu Wang | Hui Liu | Jiaojiao Yin | Wu Zhong | Chuanrong Hu | Dongping He | Xingguo Wang
Source: European Journal of Lipid Science and Technology (article, 2023-06-27)
Field: Chemistry — Organic Chemistry

Investigation of hotpot oil based on beef tallow and flavored rapeseed oil in commercial hotpot seasoning Abstract This study aimed to investigate the quality of hotpot oil from various hotpot seasonings. For this, 12 representative hotpot seasonings with beef tallow (BT) and flavored rapeseed oil (FRO) were collected before the hotpot oil was extracted. The oil content, sensory evaluation scores, physiochemical properties, fatty acid composition, harmful substances, and nutrient content of the hotpot oil were subsequently analyzed. The results showed that the oil content of the hotpot seasoning was 38.3%–58.2%. Furthermore, the BT hotpot oils produced better sensory scores (7–8.5), and their oxidative stability (12.08–13.17 h) was higher on average than that of the FRO hotpot oils. Additionally, the FRO hotpot oils had higher contents of unsaturated fatty acid (81.70%–97.32%), phytosterol (3466.07–6110.37 ppm), tocopherol (182.91–1276.17 mg kg −1 ), and polyphenol (34.48–61.94 mg kg −1 ). The factor analyses revealed that the FRO and BT hotpot oils were significantly different and were affected by the iodine value, acid value, and linoleic acid and phytosterol contents. Practical applications : It is necessary to improve the nutritional value and taste of hotpot oils to facilitate rapid development in the hotpot seasoning industry. This study showed FRO was a positive mediator of antioxidant, anti‐inflammatory, and anticancer effects owing to its richness of nutritional compounds, such as polyphenols, phytosterols, and tocopherols. In comparison, BT was found to have a lower nutritional value than FRO but added a unique taste and aroma to the hotpot. The use of blended oil as raw oil could also improve the quality of hotpot oil. This information will provide an important guide to the nutritional value and industrial production of hotpot oil. Blended oil is a promising raw oil for future use in hotpot seasoning processing to meet consumer demands for nutritious and pleasantly flavored hotpot oil. Food science ; Seasoning ; Iodine value ; Chemistry ; Menthol ; Organic chemistry ; Raw material Edible Oils Quality and Analysis ; Antioxidant Activity and Oxidative Stress ; Meat and Animal Product Quality