Absorption and reduced scattering coefficients (μ(a) and μ'(s)) of adult heads have been noninvasively determined by time-resolved reflectance measurements. The finite difference time domain (FDTD) analysis was used to calculate time-resolved reflectance from realistic adult head models with brain grooves containing a non-scattering layer. In vivo time-resolved reflectances of human heads were measured by a system composed of a time-correlated single photon counter and a diode laser. By minimizing the objective functions that compare theoretical and experimental time resolved reflectances, μ(a) and μ'(s) of brain were determined. It became clear that time-resolved measurements have enough sensitivity to determine both μ(a) and μ'(s) for superficial tissues, gray matter and white matter, except μ(s) for white matter.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1109/EMBC.2014.6944217 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Cortical encoding of spatial structure and semantic content in 3D natural scenes.
J Neurosci
January 2025
Department of Neuroscience and Biomedical Engineering, Aalto University, Espoo FI-00076, Finland.
Our visual system enables us to effortlessly navigate and recognize real-world visual environments. Functional magnetic resonance imaging (fMRI) studies suggest a network of scene-responsive cortical visual areas, but much less is known about the temporal order in which different scene properties are analysed by the human visual system. In this study, we selected a set of 36 full-colour natural scenes that varied in spatial structure and semantic content that our male and female human participants viewed both in 2D and 3D while we recorded magnetoencephalography (MEG) data.
View Article and Find Full Text PDFPiezochromic Luminescence of Pyrene Derivatives Polymorphism around Excimer Forming Processs.
Chemistry
January 2025
Northeastern University, Department of Materials Physics and Chemistry, No.11, Wenhua Road, Lane 3,Heping District, 110819, Shenyang, CHINA.
Pyrene aggregates, as classic luminescent materials, are of great interest from a scientific viewpoint owing to the development of optoelectronic materials. In this study, we designed a compound 1,4,5-triphenyl-2-(pyren-1-yl)-4,5-dihydro-1H-imidazole (IM-PY) which was achieved with two crystalline polymorphs (IMPY-G and IMPY-B). They exhibit the green emission and the blue emission, respectively, both with pyrene serving as the luminescent core.
View Article and Find Full Text PDFParticle Markov Chain Monte Carlo Approach to Inference in Transient Surface Kinetics.
J Chem Theory Comput
January 2025
Department of Electrical & Computer Engineering, Stony Brook University, Stony Brook, New York 11794, United States.
In this work, we develop a novel Bayesian approach to study the adsorption and desorption of CO onto a Pd(111) surface, a process of great importance in natural sciences. The motivation for this work comes from the recent availability of time-resolved infrared spectroscopy data and the need for model interpretability and uncertainty quantification in chemical processes. The objective is to learn the relevant parameters that characterize the process: coverage with time, rate constants, activation energies, and pre-exponential factors.
View Article and Find Full Text PDFSpectroscopy and Dynamics of the Dipole-Bound States of -, -, and -Methylphenolate Anions.
J Phys Chem A
January 2025
Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea.
A photodetachment and photoelectron spectroscopic study by employing a cryogenically cooled ion trap combined with a velocity-map imaging setup has been carried out to unravel the vibrational structures and autodetachment dynamics of the dipole-bound states (DBSs) of -, -, and -methylphenolate anions (-, -, and -CHPhO). The electron binding energy of the DBS increases monotonically with the increase of the neutral dipole moment to give respective values of 66 ± 15, 123 ± 18, or 154 ± 14 cm for the -, -, or -isomer. The different electron-donating effects of the methyl moieties in the three geometrically different isomers seem to be reflected in the experiment.
View Article and Find Full Text PDFTime-resolved Coulomb explosion imaging of vibrational wave packets in alkali dimers on helium nanodroplets.
J Chem Phys
December 2024
Department of Chemistry, Aarhus University, Langelandsgade 140, 8000 Aarhus C, Denmark.
Vibrational wave packets are created in the lowest triplet state 13Σu+ of K2 and Rb2 residing on the surface of helium nanodroplets, through non-resonant stimulated impulsive Raman scattering induced by a moderately intense near-infrared laser pulse. A delayed, intense 50-fs laser pulse doubly ionizes the alkali dimers via multiphoton absorption and thereby causes them to Coulomb explode into a pair of alkali ions Ak+. From the kinetic energy distribution P(Ekin) of the Ak+ fragment ions, measured at a large number of delays, we determine the time-dependent internuclear distribution P(R, t), which represents the modulus square of the wave packet within the accuracy of the experiment.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!