134 results match your criteria: "Institute of Atmospheric Optics[Affiliation]"

Electrospun poly(ε-caprolactone) (PCL)-based scaffolds are widely used in tissue engineering. However, low cell adhesion remains the key drawback of PCL scaffolds. It is well known that nitrogen-doped diamond-like carbon (N-DLC) coatings deposited on the surface of various implants are able to enhance their biocompatibility and functional properties.

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The far-infrared absorption spectrum of monodeuterated water vapor, HDO, is analyzed using three high-sensitivity absorption spectra recorded by high-resolution Fourier transform spectroscopy at the SOLEIL synchrotron facility. The gas sample was obtained using a 1:1 mixture of HO and DO leading to a HDO abundance close to 50%. The room temperature spectra recorded in the 50-720 cm range cover most of the rotational band.

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A standard measuring gas cell used in absorption spectrometers is a cylinder enclosed by two transparent windows. The Fabry-Perot effects caused by multiple reflections of terahertz waves between these windows produce significant variations in the transmitted radiation intensity. Therefore, the Fabry-Perot effects should be taken into account to correctly measure absorption spectra in Bouguer law-based absorption spectroscopy.

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First Line Lists for Triatomic Sulfur-Containing Molecules: SO and S.

J Phys Chem A

September 2024

Groupe de Spectrométrie Moléculaire et Atmosphérique UMR CNRS 7331, UFR Sciences BP 1039, Reims Cedex 2 51687, France.

Article Synopsis
  • This paper introduces the first line lists for disulfur monoxide (SO) and thiozone (S) at room temperature, providing important data for potential detection in the Venusian atmosphere where sulfur chemistry is significant.
  • The researchers used advanced computational methods to create accurate potential energy and dipole moment surfaces, enabling a detailed analysis of the complex infrared spectra for these short-lived molecules, which is lacking in experimental data.
  • The study provides line intensities and simulations for the rotation-vibration patterns of SO and S, using comparisons to recent experimental spectra, aiming to enhance the understanding and application of these molecules in atmospheric studies.
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Rovibrational Line Lists of Triplet and Singlet Methylene.

J Phys Chem A

August 2024

Laboratory of Theoretical Spectroscopy, V.E. Zuev Institute of Atmospheric Optics SB RAS 1, Akademician Zuev Sq., Tomsk 634055, Russia.

The methylene molecule (CH) is a short-lived radical with lacking data on its spectral line intensities. Although the lifetime of CH is extremely short under Earth's conditions, it exists in a free form in interstellar media. CH is an important intermediate species in chemical reactions associated with the formation and destruction of complex hydrocarbons.

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Optical spectroscopy is studied to contribute to skin cancer diagnosis. Indeed, optical spectra are modified along cancer progression and provide complementary information (e.g.

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The infrared absorption spectrum of radioactive water isotopologue HO.

Spectrochim Acta A Mol Biomol Spectrosc

April 2024

Instituto de Fisica Gleb Wataghin, Universidade Estadual de Campinas, Campinas, SP, 13083-859, Brazil.

A room temperature line list for the HO radioactive isotopologue of the water molecule is computed using the variational nuclear-motion DVR3D program suite and an empirical high-precision potential energy function. The line list consists of rotation-vibrational energies and Einstein-A coefficients, covering a wide spectral range from 0 to 25000 cm and the total angular momenta J up to 30. Estimates of air-broadening coefficients are provided.

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This treatise studies a microoptoelectromechanical accelerometer (MOEMA) with an optical measuring transducer built according to the optical tunneling principle (evanescent coupling). The work discusses the design of the accelerometer's microelectromechanical sensing element (MSE) and states the requirements for the design to achieve a sensitivity threshold of 1 µg m/s at a calculated eigenvalue of the MSE. The studies cover the selection of the dimensions, mass, eigenfrequency and corresponding stiffness of the spring suspension, gravity-induced cross-displacements.

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Energies and lifetimes of vibrational resonances were computed for O-enriched isotopologue O = {OOO and OOO} of the ozone molecule using hyperspherical coordinates and the method of complex absorbing potential. Various types of scattering resonances were identified, including roaming OO-O rotational states, the series corresponding to continuation of bound vibrational resonances of highly excited bending or symmetric stretching vibrational modes. Such a series become metastable above the dissociation limit.

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The high resolution absorption spectrum of methane in the 10 800-14 000 cm region: literature review, new results and perspectives.

Phys Chem Chem Phys

December 2023

Laboratoire de Météorologie Dynamique/IPSL, CNRS, Sorbonne Université, École Normale Supérieure, Université PSL, Ecole Polytechnique, Institut Polytechnique de Paris, 75005 Paris, France.

The recent development of high resolution spectrographs for exoplanetary research in the visible range makes suitable an improvement of our knowledge of the high resolution spectrum of methane. In this contribution, the weak and highly congested absorption spectrum of methane in the 10 800-14 000 cm region (0.71-0.

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Article Synopsis
  • Ozone plays a vital role in atmospheric chemistry, climate change, and human health due to its strong absorption of Earth's outgoing radiation, particularly in the THz range.
  • This study presents the first high-resolution analysis of ozone spectra in the THz range using SOLEIL's Synchrotron light source, showcasing the detection of numerous ozone transitions and improvements over previous data.
  • New measurements have revealed significant deviations from existing databases, especially for high quantum number energy levels, leading to the creation of updated linelists for better atmospheric modeling and transmittance predictions.
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Wildfire plume ageing in the Photochemical Large Aerosol Chamber (PHOTO-LAC).

Environ Sci Process Impacts

January 2024

Department of Analytical and Technical Chemistry, Chair of Analytical Chemistry, Joint Mass Spectrometry Centre (JMSC), University of Rostock, 18059, Rostock, Germany.

Plumes from wildfires are transported over large distances from remote to populated areas and threaten sensitive ecosystems. Dense wildfire plumes are processed by atmospheric oxidants and complex multiphase chemistry, differing from processes at typical ambient concentrations. For studying dense biomass burning plume chemistry in the laboratory, we establish a Photochemical Large Aerosol Chamber (PHOTO-LAC) being the world's largest aerosol chamber with a volume of 1800 m and provide its figures of merit.

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The analysis and modeling of high-resolution spectra of nonrigid molecules require a specific Hamiltonian and group-theoretical formulation that differs significantly from that of more familiar rigid systems. Within the framework of Hougen-Bunker-Johns (HBJ) theory, this paper is devoted to the construction of a nonrigid Hamiltonian based on a suitable combination of numerical calculations for the nonrigid part in conjunction with the irreducible tensor operator method for the rigid part. For the first time, a variational calculation from ab initio potential energy surfaces is performed using the HBJ kinetic energy operator built from vibrational, large-amplitude motion, and rotational tensor operators expressed in terms of curvilinear and normal coordinates.

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In this work, we report rovibrational energy levels for four isotopologues of methylene (CH , CHD, CD , and CH ) in their ground triplet electronic state ( B ) from variational calculation up to ~10,000 cm and using a new accurate ab initio potential energy surface (PES). Triplet methylene exhibits a large-amplitude bending vibration and can reach a quasilinear configuration due to its low barrier (~2000 cm ). To construct the ab initio PES, the Dunning's augmented correlation-consistent core-valence orbital basis sets were employed up to the sextuple-ζ quality [aug-cc-pCVXZ, X = T, Q, 5, and 6] combined with the single- and double-excitation unrestricted coupled cluster approach with a perturbative treatment of triple excitations [RHF-UCCSD(T)].

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Prolonged and Controllable Release of Doxorubicin Hydrochloride from the Composite Electrospun Poly(ε-Caprolactone)/Polyvinylpyrrolidone Scaffolds.

J Pharm Sci

November 2023

B.P. Veinberg Research and Educational Center, Tomsk Polytechnic University, Tomsk, Russian Federation; V.E. Zuev Institute of Atmospheric Optics, Siberian Branch of the Russian Academy of Sciences, Tomsk, Russian Federation. Electronic address:

Burst release, typical for the drug-loaded electrospun poly(ε-caprolactone) (PCL) scaffolds is unfavorable in case of cytostatics due to the toxic levels reached during the initial implantation period. In the present short communication, we report an unexpected ability of the composite scaffolds made of PCL and water-soluble polyvinylpyrrolidone (PVP) to provide long-term release of widely used anti-cancer drug doxorubicin hydrochloride (DOX-HCl). That effect was observed for electrospun DOX-HCl-loaded composite scaffolds based on PCL and PVP with various mass ratios (100/0, 95/5, 90/10, 75/25 and 50/50).

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The review is aimed on the analysis the abilities of noninvasive diagnostics and monitoring of diabetes mellitus (DM) and DM-associated complications through volatile molecular biomarkers detection in the exhaled breath. The specific biochemical reactions in the body of DM patients and their associations with volatile molecular biomarkers in the breath are considered. The applications of optical spectroscopy methods, including UV, IR, and terahertz spectroscopy for DM-associated volatile molecular biomarkers measurements, are described.

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Analysis of experimental spectra of phosphine in the Tetradecad range near 2.3 μm using ab initio calculations.

Spectrochim Acta A Mol Biomol Spectrosc

December 2023

Laboratory of Theoretical Spectroscopy, V.E. Zuev Institute of Atmospheric Optics, SB RAS, 1, Academician Zuev square, 634021 Tomsk, Russia.

Due to its major interest for the chemistry of planetary atmospheres and exobiology, accurate spectroscopy data of phosphine are required for the search of signatures of this molecule in astronomical observations. In this work, high resolution infrared laboratory spectra of phosphine were analyzed for the first time in the full Tetradecad region (3769-4763 cm) involving 26 rotationally resolved bands. Overall, 3242 lines were assigned in spectra previously recorded by Fourier transform spectroscopy at temperatures 200 K and 296 K, using a combined theoretical model based on ab initio calculations.

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This study presents the results of the classification of diffuse reflectance (DR) spectra and multiexcitation autofluorescence (AF) spectra that were collected in vivo from precancerous and benign skin lesions at three different source detector separation (SDS) values. Spectra processing pipeline consisted of dimensionality reduction, which was performed using principal component analysis (PCA), followed by classification step using such methods as support vector machine (SVM), multilayered perceptron (MLP), linear discriminant analysis (LDA), and random forest (RF). In order to increase the efficiency of lesion classification, several data fusion methods were applied to the classification results: majority voting, stacking, and manual optimization of weights.

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The most commonly occurring malignant brain tumors are gliomas, and among them is glioblastoma multiforme. The main idea of the paper is to estimate dependency between glioma tissue and blood serum biomarkers using Raman spectroscopy. We used the most common model of human glioma when continuous cell lines, such as U87, derived from primary human tumor cells, are transplanted intracranially into the mouse brain.

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Adipose tissue (AT) optical properties for physiological temperatures and in vivo conditions are still insufficiently studied. The AT is composed mainly of packed cells close to spherical shape. It is a possible reason that AT demonstrates a very complicated spatial structure of reflected or transmitted light.

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The results of a rigorous study of the two first pure rotational transitions of CO perturbed by Ar are presented. The experimental part is based on the use of three different spectrometers covering together the pressure range from 0.02 up to 1500 torr.

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The surface hydrophobicity of poly(ε-caprolactone) electrospun scaffolds prevents their interactions with cells and tissue integration. Although plasma treatment of scaffolds enhances their hydrophilicity, this effect is temporary, and the hydrophobicity of the scaffolds is restored in about 30 days. In this communication, we report a method for hydrophilization of poly(ε-caprolactone) electrospun scaffolds for more than 6 months.

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Nonlinear Propagation and Filamentation on 100 Meter Air Path of Femtosecond Beam Partitioned by Wire Mesh.

Sensors (Basel)

August 2022

Institute of Modern Optics, Tianjin Key Laboratory of Micro-Scale Optical Information Science and Technology, Nankai University, Tianjin 300350, China.

High-intensity (∼1 TW/cm2 and higher) region formed in the propagation of ∼60 GW, 90 fs Ti:Sapphire laser pulse on a ∼100 m path in air spans for several tens of meters and includes a plasma filament and a postfilament light channel. The intensity in this extended region is high enough to generate an infrared supercontinuum wing and to initiate laser-induced discharge in the gap between the electrodes. In the experiment and simulations, we delay the high-intensity region along the propagation direction by inserting metal-wire meshes with square cells at the laser system output.

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New Theoretical Infrared Line List for the Methyl Radical with Accurate Vibrational Band Origins from High-Level Ab Initio Calculations.

J Phys Chem A

September 2022

Groupe de Spectrométrie Moléculaire et Atmosphérique UMR CNRS 7331, UFR Sciences BP 1039, 51687 Reims Cedex 2, France.

In the present work, high-level ab initio calculations were carried out for the ground electronic state of the methyl radical (CH). Dunning's augmented correlation-consistent orbital basis sets were employed up to the quintuple-ζ valence quality with the core-valence electron correlation [aug-cc-pCV5Z] combined with the single- and double-excitation unrestricted coupled-cluster approach with a perturbative treatment of triple excitations [RHF-UCCSD(T)]. The explicitly correlated version of the coupled-cluster approach [RHF-UCCSD(T)-F12x{x = a, b}] was additionally applied with the core-valence cc-pCVQZ-F12 basis set in order to study convergence with respect to the basis set size.

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The MD method for modeling vermiculite containing Na, Rb, Cs, Mg, and Ba cations shows the following: With a weak swelling of clay, the temperature has no significant effect on the diffusion of water and cations through vermiculite. With a high content of water in vermiculite, the effect of temperature on the diffusion coefficient of water is greater than that of cations. We studied the structure of RDF ions in Na-vermiculite, in which some of the cations are replaced by Rb, Cs, Mg, and Ba.

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