6,946 research outputs found
Peroxynitrite decomposition catalyst ameliorates renal damage and protein nitration in cisplatin-induced nephrotoxicity in rats
BACKGROUND: Oxidative stress is involved in cisplatin-nephrotoxicity. However, it has not completely established if reactive nitrogen species and nitrosative stress are involved in this experimental model. The purpose of this work was to study the role of peroxynitrite, a reactive nitrogen specie, in cisplatin-nephrotoxicity using the compound 5,10,15,20-tetrakis (4-sulfonatophenyl) porphyrinato iron (III) (FeTPPS), a soluble complex able to metabolize peroxynitrite. RESULTS: In rats treated with cisplatin (a single intraperitoneal dose of 7.5 mg/kg body weight), renal nitrosative stress was made evident by the increase in 3-nitrotyrosine on day 3. In addition, cisplatin-induced nephrotoxicity was evident by the histological damage of proximal tubular cells and by the increase in (a) serum creatinine, (b) blood urea nitrogen, and (c) urinary excretion of N-acetyl-β-D-glucosaminidase and total protein. Cisplatin-induced nitrosative stress and nephrotoxicity were attenuated by FeTPPS-treatment (15 mg/kg body weight, intraperitoneally, every 12 hours for 3 days). CONCLUSIONS: Nitrosative stress is involved in cisplatin-induced nephrotoxicity in rats. Our data suggest that peroxynitrite is involved, at least in part, in cisplatin-induced nephrotoxicity and protein nitration
Geodesics of Hayward black hole surrounded by quintessence
Basing on the ideas used by Kiselev, we study the Hayward black hole
surrounded by quintessence. By setting for the quintessence state parameter at
the special case of , using the metric of the black hole
surrounded by quintessence and the definition of the effective potential, we
analyzed in detail the null geodesics for different energies. We also analyzed
the horizons of the Hayward black hole surrounded by quintessence as well as
the shadow of the black hole
Stereoscopic vision in the absence of the lateral occipital cortex
Both dorsal and ventral cortical visual streams contain neurons sensitive to binocular disparities, but the two streams may underlie different aspects of stereoscopic vision. Here we investigate stereopsis in the neurological patient D.F., whose ventral stream, specifically lateral occipital cortex, has been damaged bilaterally, causing profound visual form agnosia. Despite her severe damage to cortical visual areas, we report that DF's stereo vision is strikingly unimpaired. She is better than many control observers at using binocular disparity to judge whether an isolated object appears near or far, and to resolve ambiguous structure-from-motion. DF is, however, poor at using relative disparity between features at different locations across the visual field. This may stem from a difficulty in identifying the surface boundaries where relative disparity is available. We suggest that the ventral processing stream may play a critical role in enabling healthy observers to extract fine depth information from relative disparities within one surface or between surfaces located in different parts of the visual field
Controlled Irradiative Formation of Penitentes
Spike-shaped structures are produced by light-driven ablation in very
different contexts. Penitentes 1-4 m high are common on Andean glaciers, where
their formation changes glacier dynamics and hydrology. Laser ablation can
produce cones 10-100 microns high with a variety of proposed applications in
materials science. We report the first laboratory generation of
centimeter-scale snow and ice penitentes. Systematically varying conditions
allows identification of the essential parameters controlling the formation of
ablation structures. We demonstrate that penitente initiation and coarsening
requires cold temperatures, so that ablation leads to sublimation rather than
melting. Once penitentes have formed, further growth of height can occur by
melting. The penitentes intially appear as small structures (3 mm high) and
grow by coarsening to 1-5 cm high. Our results are an important step towards
understanding and controlling ablation morphologies.Comment: Accepted for publication in Physical Review Letter
Assessing the green transition priorities of SMEs: A large scale web mining approach
[EN] Company websites are a rich source of data that exhibit the activities,
intentions, and strategies of the respective companies. Aggregating that
information at a sector, company size, and country level has the potential to
reveal the underlying behavior of the different units. This paper presents a
pilot study in which a sample of more than 32,000 companies from Germany,
France, Italy, and Spain has been analyzed to assess their evolution in the
sustainability transition over the last 15 years.Doménech I De Soria, J.; Vicente, M.; MartÃnez Cabanes, H.; De Pedraza GarcÃa, P. (2022). Assessing the green transition priorities of SMEs: A large scale web mining approach. En 4th International Conference on Advanced Research Methods and Analytics (CARMA 2022). Editorial Universitat Politècnica de València. 278-278. http://hdl.handle.net/10251/18976027827
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