[Intraoperative ultrasound-assisted surgery of spinal tumors].

Objective: To improve technique of intraoperative ultrasound-assisted microsurgery of spinal tumors.

Material And Methods: There were 68 patients with 70 spinal tumors who underwent intraoperative ultrasound-assisted resection between 2007 and 2018. Age of patients varied from 21 to 80 (mean 48.

External Multicenter Study of Reliability and Reproducibility for Lower Cervical Spine Injuries Classification Systems-Part 1: A Comparison of Morphological Schemes.

Study Design: Multicenter observational survey study.

Objectives: To quantify and compare the inter- and intraobserver reliability of Allen-Fergusson (A-F), Harris, Argenson, and AOSpine (AOS) classifications for cervical spine injuries, in a multicentric survey of neurosurgeons with different levels of experience.

Methods: We used data of 64 consecutive patients.

Optimization of the Photon Path Length Probability Density Function-Simultaneous (PPDF-S) Method and Evaluation of CO₂ Retrieval Performance Under Dense Aerosol Conditions.

The photon path length probability density function-simultaneous (PPDF-S) algorithm is effective for retrieving column-averaged concentrations of carbon dioxide (XCO₂) and methane (XCH₄) from Greenhouse gases Observing Satellite (GOSAT) spectra in Short Wavelength InfraRed (SWIR). Using this method, light-path modification attributable to light reflection/scattering by atmospheric clouds/aerosols is represented by the modification of atmospheric transmittance according to PPDF parameters. We optimized PPDF parameters for a more accurate XCO₂ retrieval under aerosol dense conditions based on simulation studies for various aerosol types and surface albedos.

Simultaneous retrieval of atmospheric CO2 and light path modification from space-based spectroscopic observations of greenhouse gases: methodology and application to GOSAT measurements over TCCON sites.

This paper presents an improved photon path length probability density function method that permits simultaneous retrievals of column-average greenhouse gas mole fractions and light path modifications through the atmosphere when processing high-resolution radiance spectra acquired from space. We primarily describe the methodology and retrieval setup and then apply them to the processing of spectra measured by the Greenhouse gases Observing SATellite (GOSAT). We have demonstrated substantial improvements of the data processing with simultaneous carbon dioxide and light path retrievals and reasonable agreement of the satellite-based retrievals against ground-based Fourier transform spectrometer measurements provided by the Total Carbon Column Observing Network (TCCON).

Retrieval of atmospheric methane from high spectral resolution satellite measurements: a correction for cirrus cloud effects.

We assessed the accuracy of methane (CH(4)) retrievals from synthetic radiance spectra particular to Greenhouse Gases Observing Satellite observations. We focused on estimating the CH(4) vertical column amount from an atmosphere that includes thin cirrus clouds, taking into account uncertain meteorological conditions. A photon path-length probability density function (PPDF)-based method was adapted to correct for atmospheric scattering effects in CH(4) retrievals.

Inverse scattering problem for mixed-phase and ice clouds. I. Numerical simulation of particle sizing from phase-function measurements.

We propose a new method of particle size retrieval for mixed-phase and ice crystal clouds. The method enables us to identify each component of a bicomponent cloud composed of water droplets and ice crystals and to retrieve a size distribution separately for each cloud component. We explore the method's capability by using sythetic multiangular data of scattered-light intensity.

Parameterization of aerosol and cirrus cloud effects on reflected sunlight spectra measured from space: application of the equivalence theorem.

An original methodology to account for aerosol and cirrus cloud contributions to reflected sunlight is described. This method can be applied to the problem of retrieving greenhouse gases from satellite-observed data and is based on the equivalence theorem with further parameterization of the photon path-length probability density function (PPDF). Monte Carlo simulation was used to validate this parameterization for a vertically nonhomogeneous atmosphere including an aerosol layer and cirrus clouds.

Simultaneous stratospheric gas and aerosol retrievals from broadband infrared occultation measurements.

The inversion method for simultaneous gas (O3, NO2, HNO3, N2O, CH4, H2O, CFC-11, CFC-12, N2O5, and ClONO2) and aerosol retrievals from broadband continuous IR spectra of occultation measurements is described. Both gas and aerosol physical modeling with consideration of the multicomponent character of aerosol and polar stratospheric clouds (PSCs) are used to minimize the difference between measured and modeled transmittance spectra under smoothness constraints imposed on particle-size distributions for each PSC component and positive constraints on all gas and aerosol parameters. The method is tested by numerical simulations in which synthetic occultation measurements inherent to the improved limb atmospheric spectrometer are used.

New method for simultaneous gas and aerosol retrievals from space limb-scanning spectral observation of the atmosphere.

This study concerns the development of a new inversion method for simultaneous gas and aerosol retrievals in the upper layers of the atmosphere from limb-viewing multiwavelength-transmission infrared measurements. In this method, concentrations of gas species such as O3, NO2, HNO3, N2O, CH4, and H2O, and spectral dependences of the aerosol extinction coefficient are retrieved simultaneously. When this is done, smoothness constraints on the desired spectral dependencies of the aerosol extinction coefficient are used as an a priori assumption.

Optical Sizing of Ultrafine Metallic Particles: Retrieval of Particle Size Distribution from Spectral Extinction Measurements.

The inverse problem of optical sizing of ultrafine metallic particles from the spectral extinction measurements in the visible range is investigated. Solving the inverse problem becomes possible due to the strong size effect which in the framework of classical electrodynamics can be described by the dependence of complex refractive index on the particle size. It is shown that the size effect leads to the considerable increase of information content of spectral extinction data with respect to desired size composition of the particles.

Improved technique for data inversion: optical sizing of multicomponent aerosols.

Estimation of particle-size distribution is analyzed for the complicated case of compound aerosols, in which particles are distinguished by sizes and optical constants. This task arises in a number of interesting practical situations when aerosol scatterers cannot be described with a common refractive index. This is an inverse problem with a large number of variables, and questions of formal inversion are of great importance here.