1,174 research outputs found
DNA double-strand breaks induced by high NaCl occur predominantly in gene deserts
High concentration of NaCl increases DNA breaks both in cell culture and in vivo. The breaks remain elevated as long as NaCl concentration remains high and are rapidly repaired when the concentration is lowered. The exact nature of the breaks, and their location, has not been entirely clear, and it has not been evident how cells survive, replicate, and maintain genome integrity in environments like the renal inner medulla in which cells are constantly exposed to high NaCl concentration. Repair of the breaks after NaCl is reduced is accompanied by formation of foci containing phosphorylated H2AX (γH2AX), which occurs around DNA double-strand breaks and contributes to their repair. Here, we confirm by specific comet assay and pulsed-field electrophoresis that cells adapted to high NaCl have increased levels of double-strand breaks. Importantly, γH2AX foci that occur during repair of the breaks are nonrandomly distributed in the mouse genome. By chromatin immunoprecipitation using anti-γH2AX antibody, followed by massive parallel sequencing (ChIP-Seq), we find that during repair of double-strand breaks induced by high NaCl, γH2AX is predominantly localized to regions of the genome devoid of genes (“gene deserts”), indicating that the high NaCl-induced double-strand breaks are located there. Localization to gene deserts helps explain why the DNA breaks are less harmful than are the random breaks induced by genotoxic agents such as UV radiation, ionizing radiation, and oxidants. We propose that the universal presence of NaCl around animal cells has directly influenced the evolution of the structure of their genomes
Microcotyle omanae n. sp. (Monogenea: Microcotylidae), a parasite of Cheimerius nufar (Valenciennes) (Sparidae) from the Arabian Sea
Microcotyle omanae n. sp. (Monogenea: Microcotylidae) is described from the gills of Cheimerius nufar (Valenciennes) (Sparidae) from the Arabian Sea. The new species closely resembles Microcotyle arripis Sandars, 1945, M. helotes Sandars, 1944, M. caudata Goto, 1984 and M. sebastis Goto, 1984, which have also been found in the Indo-Pacific. Microcotyle omanae n. sp. differs from M. arripis, M. helotes and M. caudata by its greater number of testes, from M. arripis, M. helotes by its greater length of the genital atrium, length/width ratio of the genital atrium and length of the eggs, and from M. helotes also in greater width of the clamps, from M. caudata and M. sebastis in its greater number of clamps and additionally from M. sebastis by its smaller genital atrial spines and clamps and by the ratio between length and width of the genital atrium. Moreover, the mature specimens of the new species have greater average body length than all above mentioned species. Correlations between 15 morphometric characters and body length are analysed in the new species, and their significance for species differentiation is discussed
Local activation of cannabinoid CB1 receptors in the urinary bladder reduces the inflammation-induced sensitization of bladder afferents
<p>Abstract</p> <p>Background</p> <p>Systemic administration of cannabinoid agonists is known to reduce pain induced by bladder inflammation and to modulate cystometric parameters <it>in vivo</it>. We have previously reported that intravesical administration of a cannabinoid agonist reduces the electrical activity of bladder afferents under normal conditions. However, the effects of local activation of bladder cannabinoid receptors on afferent activity during inflammation are unknown. This study was aimed to assess the effects of intravesical administration of a cannabinoid agonist on the discharges of afferent fibers in inflamed bladders <it>ex vivo</it>. We also characterized the expression of CB<sub>1 </sub>receptors in the bladder and their localization and co-expression with TRPV1, a marker of nociceptive afferents.</p> <p>Results</p> <p>Compared to untreated animals, afferent fiber activity in inflamed bladders was increased for intravesical pressures between 10 and 40 mmHg. Local treatment with a non selective cannabinoid agonist (AZ12646915) significantly reduced the afferent activity at intravesical pressures above 20 mmHg. This effect was blocked by AM251 but not by AM630 (selective for CB<sub>1 </sub>and CB<sub>2 </sub>respectively). Finally, CB<sub>1 </sub>was co-expressed with TRPV1 in control and inflamed bladders.</p> <p>Conclusion</p> <p>These results demonstrate that sensitization of bladder afferents induced by inflammation is partly suppressed by intravesical activation of cannabinoid receptors, an effect that appears to be mediated by CB<sub>1 </sub>receptors. Also, TRPV1 positive fibers were found to co-express CB<sub>1</sub>, supporting the hypothesis of a direct action of the cannabinoid agonist on nociceptive afferents. Taken together, these results indicate a peripheral modulation by the cannabinoid system of bladder hypersensitivity during inflammation.</p
Measurements of integral muon intensity at large zenith angles
High-statistics data on near-horizontal muons collected with Russian-Italian
coordinate detector DECOR are analyzed. Precise measurements of muon angular
distributions in zenith angle interval from 60 to 90 degrees have been
performed. In total, more than 20 million muons are selected. Dependences of
the absolute integral muon intensity on zenith angle for several threshold
energies ranging from 1.7 GeV to 7.2 GeV are derived. Results for this region
of zenith angles and threshold energies have been obtained for the first time.
The dependence of integral intensity on zenith angle and threshold energy is
well fitted by a simple analytical formula.Comment: 4 pages, 4 figures, 1 tabl
Palladium Nanoparticles–Polypyrrole Composite as Effective Catalyst for Fluoroalkylation of Alkenes
© 2018, Springer Science+Business Media, LLC, part of Springer Nature. Abstract: Palladium nanoparticles–polypyrrole composite (Pd/PPy) catalyzes the addition of perfluoroalkyl halides to olefins to produce a variety of products with good yields. An effective fluoroalkylation technique tested with various olefins, fluoroalkyl halides and Pd/PPy was developed. The reaction proceeds highly efficient under mild phosphine-free reaction conditions with different substrates, easy catalyst recycling and provides a general and straightforward access to fluoroalkylated products. Furthermore, we were able to control whether the addition of perfluoroalkyl occurs with various monomer (fluoroalkylated alkene or alkane with RF and OH moieties) or dimer formation (under electrochemical conditions). Graphical Abstract: [Figure not available: see fulltext.]
One-Dimensional Discrete Stark Hamiltonian and Resonance Scattering by Impurities
A one-dimensional discrete Stark Hamiltonian with a continuous electric field
is constructed by extension theory methods. In absence of the impurities the
model is proved to be exactly solvable, the spectrum is shown to be simple,
continuous, filling the real axis; the eigenfunctions, the resolvent and the
spectral measure are constructed explicitly. For this (unperturbed) system the
resonance spectrum is shown to be empty. The model considering impurity in a
single node is also constructed using the operator extension theory methods.
The spectral analysis is performed and the dispersion equation for the
resolvent singularities is obtained. The resonance spectrum is shown to contain
infinite discrete set of resonances. One-to-one correspondence of the
constructed Hamiltonian to some Lee-Friedrichs model is established.Comment: 20 pages, Latex, no figure
System Approach to the Development of Intelligent Complexes of Oncological Diagnostics
The system approach to the development of intellectual complexes in cancer diagnosis are discussed in the article. Distinctive features of this approach: the participation of pathologist at the stage of description of recognizable images (the description is based on traditional assessments of quality informative features of tumors); the set of the most similar probabilistic diagnoses is forming on the classification stage of recognition; final histological diagnosis is made by pathologist. The proposed approach has been successfully tested in clinical practice.
Keywords: image processing, image description, image classification, pattern recognition, qualitative attributes of tumor images, interactive recognition, cancer diagnosis, decision support syste
Discrete Integrable Systems and Hodograph Transformations Arising from Motions of Discrete Plane Curves
We consider integrable discretizations of some soliton equations associated
with the motions of plane curves: the Wadati-Konno-Ichikawa elastic beam
equation, the complex Dym equation, and the short pulse equation. They are
related to the modified KdV or the sine-Gordon equations by the hodograph
transformations. Based on the observation that the hodograph transformations
are regarded as the Euler-Lagrange transformations of the curve motions, we
construct the discrete analogues of the hodograph transformations, which yield
integrable discretizations of those soliton equations.Comment: 19 page
EVALUATION OF CHANGES IN TUBERCULOSIS EPIDEMIOLOGICAL RATES AMONG PRISONERS IN THE PENITENTIARY SYSTEM OF RUSSIA AND SMOLENSK REGION
The article presents the results of retrospective analysis of tuberculosis epidemic situation among prisoners in Smolensk Region and its comparison with the same rates in the Russian Federation for 2007-2013. During those years positive changes had been observed in tuberculosis incidence, mortality and prevalence rates. The rates for the region were significantly lower compared to the rates in the penitentiary system for the whole country. Tuberculosis incidence in remand prisons of Smolensk Region was higher compared to the same in penal colonies and overall rate in the penitentiary system of Smolensk Region. Those in the age from 21 to 40 years prevailed among tuberculosis patients in Smolensk Region during the period being analyzed
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