355 research outputs found
Analysis of Synovial Fluid for Study of Diseases of Joints Using the Method of Raman Spectroscopy
This paper presents the results of experimental studies using the synovial fluid Raman spectroscopy method, which was obtained from the joint cavity during the operation. By analyzing the composition of the synovial fluid, it was found that with the development of the degenerative-dystrophic process in the synovial fluid of the affected joint, the total number of components at wave numbers: 1155 cm-1 (Hyaluronic acid (C-O, C-C)) and 1250 cm-1 (Amide III). The introduced optical coefficients allow estimating the synovial fluid in osteoarthritis and further this method of Raman spectroscopy can become a new diagnostic screening for the detection of articular pathology.
Keywords: Raman spectroscopy, osteoarthrosis, synovial flui
Spectral Studies of Rat Bone Tissue in Modeling Osteoporosis and Effectiveness of Treatment By Hydroxyapatite
Presents the result of experiments on the study of the model of osteoporosis in rats using Raman spectroscopy and the effectiveness of its treatment with hydroxyapatite. Were revealed spectral differences between groups of samples (control group, group with the model of osteoporosis and a group with the model of osteoporosis after treatment with hydroxyapatite). In addition, optical coefficients were introduced to evaluate the effectiveness of treatment.
Keywords: Raman spectroscopy, optical coefficients, osteoporosis, hydroxyapatite, collagen matri
Analysis of micro- and nano-structures of the corneal surface of Drosophila and its mutants by atomic force microscopy and optical diffraction.
Drosophila melanogaster is a model organism instrumental for numerous biological studies. The compound eye of this insect consists of some eight hundred individual ommatidia or facets, ca. 15 µm in cross-section. Each ommatidium contains eighteen cells including four cone cells secreting the lens material (cornea). High-resolution imaging of the cornea of different insects has demonstrated that each lens is covered by the nipple arrays--small outgrowths of ca. 200 nm in diameter. Here we for the first time utilize atomic force microscopy (AFM) to investigate nipple arrays of the Drosophila lens, achieving an unprecedented visualization of the architecture of these nanostructures. We find by Fourier analysis that the nipple arrays of Drosophila are disordered, and that the seemingly ordered appearance is a consequence of dense packing of the nipples. In contrast, Fourier analysis confirms the visibly ordered nature of the eye microstructures--the individual lenses. This is different in the frizzled mutants of Drosophila, where both Fourier analysis and optical imaging detect disorder in lens packing. AFM reveals intercalations of the lens material between individual lenses in frizzled mutants, providing explanation for this disorder. In contrast, nanostructures of the mutant lens show the same organization as in wild-type flies. Thus, frizzled mutants display abnormal organization of the corneal micro-, but not nano-structures. At the same time, nipples of the mutant flies are shorter than those of the wild-type. We also analyze corneal surface of glossy-appearing eyes overexpressing Wingless--the lipoprotein ligand of Frizzled receptors, and find the catastrophic aberration in nipple arrays, providing experimental evidence in favor of the major anti-reflective function of these insect eye nanostructures. The combination of the easily tractable genetic model organism and robust AFM analysis represents a novel methodology to analyze development and architecture of these surface formations
Isomeric pair in photonuclear reactions on Mo at end-point bremsstrahlung energy of 35-95 MeV
The Nb photonuclear reaction
was studied using the electron beam from the NSC KIPT linear accelerator
LUE-40. Experiment was performed using the activation and off-line -ray
spectrometric technique. The experimental isomeric yield ratio was
determined for the reaction products at the end-point
bremsstrahlung energy range of 35-95 MeV. The obtained
values of are in satisfactory agreement with the
results of other authors and extend the range of previously known data. The
theoretical values of the yields and the
isomeric yield ratio for the isomeric pair from the reaction were
calculated using the partial cross-sections from the TALYS1.95 code
for six different level density models . The comparison showed a noticeable
excess (more than 3.85 times) of the experimental isomeric yield ratio over all
theoretical estimates. At the investigated range of the
theoretical dependence of on energy was confirmed -
the isomeric yield ratio smoothly decreases with increasing energy.Comment: 9 pages, 9 figures, 1 tabl
Electrophysical methods of separation of metal cations in the moving salts solution
The results of experiments on the excitation of the phenomenon of selective drift of solvated ions under the influence of an external "asymmetric" electric field to the circulating solution of calcium chloride and magnesium salts in a polar liquid dielectric - water are shown. The purpose of the experiments was to determine the influence of the field frequency and amplitude of the field strength on the excitation phenomenon, and the study of the operating characteristics of the testing apparatus - a dividing cell. The dependences of the separation efficiency of solvated cations from the frequency of the external field and the excitation threshold of the phenomenon from the field strength in the separation cell are defined
Photonuclear reactions cross-sections at energies up to 100 MeV for different experimental setups
In experiments on the electron linac LUE-40 of RDC "Accelerator" NSC KIPT,
the flux-averaged cross-sections of photonuclear reactions
,
,
,
, and
were measured using the
-activation technique. The theoretical flux-average cross-sections
were computed using the
partial cross-section values from the TALYS1.9-1.95 codes and
bremsstrahlung -flux calculated using GEANT4.9.2. Two different
experimental setups were used in the experiments: an aluminum electron absorber
and a deflecting magnet to clean the bremsstrahlung -flux from
electrons. A comparison of the flux-average cross-sections measured for two
experimental setups was performed. The possibility of using the reactions
,
,
,
, and
as monitors of the bremsstrahlung
-flux for the energy range 30-100 MeV was investigated.Comment: 8 pages, 6 figures, 1 tabl
Production of Hf in photoproton reaction Ta at energy = 35-95 MeV
The production of the nuclei in the photoproton
reaction was studied at end-point bremsstrahlung
energies = 35-95 MeV. The experiment was performed at the
electron linear accelerator LUE-40 NSC KIPT with the use of the
activation and off-line -ray spectroscopy.
The experimental values of the bremsstrahlung flux-averaged cross-sections
for the
reaction were determined, and at
MeV obtained for the first time.
The measured values, also as the literature data, are significantly exceed
the theoretical flux-averaged cross-sections . The values were calculated using the cross-section
computed with the TALYS1.95 code for six different level density
models.
A comparative analysis of the calculated total cross-sections for the
reactions and
was performed. It was shown that the
photoproton to photoneutron strength ratio is
consistent with the estimates based on the isospin selection rules and the
value from the experiment.Comment: 9 pages, 4 figures, 2 table
Magnetic system for cleaning the gamma beam at the LUE-40 electron linac output
The bremsstrahlung of accelerated electrons passing through a converter is
used to study multiparticle photo-nuclear reactions. The results of
calculations, numerical modeling, design, and testing of a special magnetic
cleaning system to obtain a "pure" beam of bremsstrahlung quanta when studying
the cross-sections of such reactions at the LUE-40 linac are presented. The
system is based on commercially available permanent magnets of rectangular
cross-sections. The maximum on-axis field is 0.9 T, which provides sufficient
separation of the electron beam and gamma rays at a distance of more than 90 mm
from the magnet.Comment: 9 pages, 8 figure
Expression of a Dominant Negative CELF Protein In Vivo Leads to Altered Muscle Organization, Fiber Size, and Subtype
CUG-BP and ETR-3-like factor (CELF) proteins regulate tissue- and developmental stage-specific alternative splicing in striated muscle. We previously demonstrated that heart muscle-specific expression of a nuclear dominant negative CELF protein in transgenic mice (MHC-CELFΔ) effectively disrupts endogenous CELF activity in the heart in vivo, resulting in impaired cardiac function. In this study, transgenic mice that express the dominant negative protein under a skeletal muscle-specific promoter (Myo-CELFΔ) were generated to investigate the role of CELF-mediated alternative splicing programs in normal skeletal muscle.Myo-CELFΔ mice exhibit modest changes in CELF-mediated alternative splicing in skeletal muscle, accompanied by a reduction of endomysial and perimysial spaces, an increase in fiber size variability, and an increase in slow twitch muscle fibers. Weight gain and mean body weight, total number of muscle fibers, and overall muscle strength were not affected.Although these findings demonstrate that CELF activity contributes to the normal alternative splicing of a subset of muscle transcripts in vivo, the mildness of the effects in Myo-CELFΔ muscles compared to those in MHC-CELFΔ hearts suggests CELF activity may be less determinative for alternative splicing in skeletal muscle than in heart muscle. Nonetheless, even these small changes in CELF-mediated splicing regulation were sufficient to alter muscle organization and muscle fiber properties affected in myotonic dystrophy. This lends further evidence to the hypothesis that dysregulation of CELF-mediated alternative splicing programs may be responsible for the disruption of these properties during muscle pathogenesis
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