15 research outputs found
Blood flow oscillations as a signature of microvascular abnormalities
Laser Doppler flowmetry (LDF) was utilized for blood ow measurements. Wavelet analysis was used to identify spectral characteristics of the LDF signal in patients with rheumatic diseases and diabetes mellitus. Baseline measurements were applied for both pathological groups. Blood flow oscillations analyses were performed by means of the wavelet transform. Higher baseline perfusion was observed in both pathological groups in comparison to controls. Differences in the spectral properties between the groups studied were revealed. The results obtained demonstrated that spectral properties of the LDF signal collected in basal conditions may be the signature of microvasculature functional state
Original Russian Text c
Abstract-The applicability of contour-crossing statistics to radio polarized intensity maps of the interstellar medium is discussed with the aim of extracting physical information on interstellar turbulence. We determine to what extent contour-crossing statistics is right for the description of narrow regions of low polarization (so-called canals), whose existence has been discussed recently by some researchers. Contour-crossing statistics can yield the characteristic sizes of small scale structures on the maps, and be used to estimate the scale of fluctuations in the interstellar medium. PACS numbers: 98.38.A
Role of Cross Helicity in Cascade Processes of MHD turbulence
The purpose of this work is to investigate the spectral properties of the
developed isotropic (non-Alfven) MHD turbulence stationary excited by an
external force, which injects the cross helicity into the flow simultaneously
with the energy. It is shown that the cross helicity blocks the spectral energy
transfer in MHD turbulence and results in energy accumulation in the system.
This accumulation proceeds until the vortex intensification compensates the
decreasing efficiency of nonlinear interactions. The formula for estimating the
average turbulence energy is obtained for the set ratio between the injected
helicity and energy. It is remarkable that the turbulence accumulates the
injected cross helicity at its low rate injection -- the integral correlation
coefficient significantly exceeds the ratio between the injected helicity and
the energy. It is shown that the spectrum slope gradually increases from "5/3"
to "2" with the cross helicity level.Comment: 4 page
Biophotonics methods for functional monitoring of complications of diabetes mellitus
The prevalence of diabetes complications is a significant public health problem with a considerable economic cost. Thus, the timely diagnosis of complications and prevention of their development will contribute to increasing the length and quality of patient life, and reducing the economic costs of their treatment. This article aims to review the current state-of-the-art biophotonics technologies used to identify the complications of diabetes mellitus and assess the quality of their treatment. Additionally, these technologies assess the structural and functional properties of biological tissues, and they include capillaroscopy, laser Doppler flowmetry and hyperspectral imaging, laser speckle contrast imaging, diffuse reflectance spectroscopy and imaging, fluorescence spectroscopy and imaging, optical coherence tomography, optoacoustic imaging and confocal microscopy. Recent advances in the field of optical noninvasive diagnosis suggest a wider introduction of biophotonics technologies into clinical practice and, in particular, in diabetes care units