1,358,162 research outputs found
Three distinct mechanisms generate oxygen free radicals in neurons and contribute to cell death during anoxia and reoxygenation
No full textIschemia is a major cause of brain damage, and patient management is complicated by the paradoxical injury that results from reoxygenation. We have now explored the generation of reactive oxygen species (ROS) in hippocampal and cortical neurons in culture in response to oxygen and glucose deprivation or metabolic inhibition and reoxygenation. Fluorescence microscopy was used to measure the rate of ROS generation using hydroethidine, dicarboxyfluorescein diacetate, or MitoSOX. ROS generation was correlated with changing mitochondrial potential (rhodamine 123), [Ca2+]c (fluo-4, fura-2, or Indo-1), or ATP consumption, indicated by increased [Mg2+]c. We found that three distinct mechanisms contribute to neuronal injury by generating ROS and oxidative stress, each operating at a different stage of ischemia and reperfusion. In response to hypoxia, mitochondria generate an initial burst of ROS, which is curtailed once mitochondria depolarize or prevented by previous depolarization with uncoupler. A second phase of ROS generation that followed after a delay was blocked by the xanthine oxidase (XO) inhibitor oxypurinol. This phase correlated with a rise in [Mg2+]c, suggesting XO activation by accumulating products of ATP consumption. A third phase of ROS generation appeared at reoxygenation. This was blocked by NADPH oxidase inhibitors and was absent in cells from gp91phox–/– knock-out mice. It was Ca2+ dependent, suggesting activation by increased [Ca2+]c during anoxia, itself partly attributable to glutamate release. Inhibition of either the NADPH oxidase or XO was significantly neuroprotective. Thus, oxidative stress contributes to cell death over and above the injury attributable to energy deprivation
Abramov glacier data base
No full textAbramov glacier data base
Data base compiled by F. Pertziger. Parts of this dataset were published in the Abramov Glacier Data Reference Book (Pertziger, 1996). Please refer to the reference book and to Kronenberg et al. (2021,2022) and Kronenberg (2022) for more details about the data and their acquisition.
The mdb file contains monthly mass balance measurements from 165 stake and nine snow pit locations, daily runoff measurements and meteorological observations. Please note, that the reported coordinates are given in a local coordinate system. Coordinates were transferred to WGS84 / UTM Zone 42N as described in Kronenberg et al. (2021) and are available in a separate file.
References
Kronenberg Marlene. (2022). Changing glacier firn in Central Asia and its impact on glacier mass balance. PhD Thesis. University of Fribourg. https://doi.org/10.51363/unifr.sth.2022.005
Kronenberg, M., Machguth, H., Eichler, A., Schwikowski, M., & Hoelzle, M. (2021). Comparison of historical and recent accumulation rates on Abramov Glacier, Pamir Alay. Journal of Glaciology, 67(262), 253–268. https://doi.org/10.1017/jog.2020.103
Kronenberg, M., Machguth, H., Pelt, W. van, Fiddes, J., Hoelzle, M., & Pertziger, F. (2022). Long-term mass balance and firn modelling for Abramov glacier, Pamir Alay. The Cryosphere Discussions, 2021–380, 1–33. https://doi.org/10.5194/tc-2021-380
Pertziger, F. I. (1996). Abramov Glacier Data Reference Book: Climate, Runoff, Mass Balance. Central Asian Hydrometeorlogical Institute
Crocidura phuquocensis Abramov 2008
No full text<p>266.</p> <p>Phu Quoc White-toothed Shrew</p> <p> <i>Crocidura phuquocensis</i></p> <p> <b>French:</b> Crocidure de Phu Quoc / <b>German:</b> Phu-Quoc-WeiRzahnspitzmaus / <b>Spanish:</b> Musarana de Phu Quoc</p> <p> <b>Taxonomy.</b> Crocidura phuquocensis Abramov et al., 2008,</p> <p>“ Northern part of Phu Quoc Island, 5 km west of Bai Thom Village, near the road Duong Dong-Bai Thom, close to the northern part of Mount Chua area, Kien Giang Province, Vietnam, 10°22°53” N, 104°00°19” E, altitude near 30 m a.s.l.”</p> <p>Molecular data showed that C. phuquocensis forms a distinct lineage. Monotypic.</p> <p> <b>Distribution.</b> Phu Quoc I, Kien Giang</p> <p>Province, S Vietnam.</p> <p> <b>Descriptive notes.</b> Head—body 68-72 mm, tail 49-59 mm, hindfoot 12-12-5 mm. No specific data are available for body weight. Condylo-basal lengths are 17-6-18-2 mm. The Phu Quoc White-toothed Shrew is medium-sized. Tail is 69-87% of head-body length. Pelage is short and dense, dark gray dorsally and ventrally, with slight brownish hue. Tail is bicolored, dark gray dorsally, and slightly paler below. Bristle hairs are present on basal 60% oftail. Skull has broad and deep rostrum.</p> <p> <b>Habitat.</b> Only known from a dipterocarp forest, near fallen trees at bottom of a mountain, at elevations of 25-40 m.</p> <p> <b>Food and Feeding.</b> No information.</p> <p> <b>Breeding.</b> No information.</p> <p> <b>Activity patterns.</b> No information.</p> <p> <b>Movements, Home range and Social organization.</b> No information.</p> <p> <b>Status and Conservation.</b> Classified as Data Deficient on The IUCN Red List.</p> <p> <b>Bibliography.</b> Abramov, Bannikova & Rozhnov (2012), Abramov, Dang Ngoc Can et al. (2013), Abramov, Jenkins et al. (2008), Abramov, Kalinin & Morozov (2007), Bannikova et al. (2011).</p>Published as part of <i>Russell A. Mittermeier & Don E. Wilson, 2018, Soricidae, pp. 332-551 in Handbook of the Mammals of the World – Volume 8 Insectivores, Sloths and Colugos, Barcelona :Lynx Edicions</i> on page 491, DOI: <a href="http://zenodo.org/record/6870843">10.5281/zenodo.6870843</a>
Inpatient Diuretic Management of Acute Heart Failure: A Practical Review
No full textThe inpatient treatment of acute heart failure (AHF) is aimed at achieving euvolemia, relieving symptoms, and reducing rehospitalization. Adequate treatment of AHF is rooted in understanding the pharmacokinetics and pharmacodynamics of select diuretic agents used to achieve decongestion. While loop diuretics remain the primary treatment of AHF, the dosing strategies of loop diuretics and the use of adjunct diuretic classes to augment clinical response can be complex. This review examines the latest strategies for diuretic management in patients with AHF, including dosing and monitoring strategies, interaction of diuretics with other medication classes, use adjunctive therapies, and assessing endpoints for diuretic. The goal of the review is to guide the reader through commonly encountered clinical scenarios and pitfalls in the diuretic management of patients with AHF.Frederik H.Verbrugge is supported by the Special Research Fund (BOF) of Hasselt University (BOF19PD04).Abramov, D (corresponding author), Loma Linda Univ, Sch Med, Div Cardiol, 11234 Anderson St,Schuman Pavil,SP-1617, Loma Linda, CA 92354 USA.
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Beam dynamics studies for the FCC-ee collimation system design
Get PDFThe electron-positron Future Circular Collider (FCC-ee) foresees stored beam energies up to 20.7 MJ, a value almost two orders of magnitude higher than any previous lepton collider. Considering the intrinsic damage potential of the FCC-ee beams, a halo collimation system is under study to protect the most sensitive equipment from unavoidable losses. Beam dynamics and tracking studies are key aspects to evaluate the cleaning performance of the collimation system, as they help in an iterative process to converge on an optimum performance. The first results of such studies, exploring various configurations of materials and collimator lengths, are presented, including also estimated beam loss distributions around the ring. In addition, an impact parameter scan on the primary collimators is studied to identify the most critical case for the protection of sensitive equipment
Anatoliy Petrovich Abramov, patriarch of economic transport science
Get PDFIntroduction. The article is devoted to the 100th anniversary of the birth of a major railway economist, Doctor of Economic Sciences, Professor Anatoliy Petrovich Abramov, who made a great contribution to the development of national economic science. The economists works reflect an extraordinary bright personality who left an indelible trace in the memory of those who worked with this outstanding person.Materials and methods. The article uses facts of Anatoliy Abramov biography, memories of his colleagues at the institute, and his achievements in the form of numerous scientific publications.Results. The article outlines the outstanding economist life journey, explores his contribution to the development of economic science in railway transport, reveals his multifaceted talent.Discussion and conclusion. This article is an opportunity to pay tribute to the memory of Anatoliy Abramov, famous railway economist, founder and head of a scientific school and remarkable person
Verbalization of Bacchic Actions in the Artistic World of Fyodor Abramov
Get PDFThe features of verbalization of Bacchic actions in the works of Fyodor Abramov (tetralogy “Brothers and Sisters”, novels “Pelageya”, “Alka”, “Mamonikha”, “Wooden Horses” and stories) are considered. The linguistic means of the individual author’s interpretation of the “Wine Drinking” sphere as a fragment of the semantic field of a literary text are analyzed. Bacchic action from the point of view of manifestation of one or another cultural semantics in it (according to M. L. Kovshova): utilitarian, functional, aesthetic, social hierarchical, ideological and spiritual is studied. It is noted that in the artistic world of Abramov, the utilitarian and functional aspects generally correspond to the general cultural ones, reflected in the paremias. It was revealed that the social-hierarchical cultural layer has its own specificity, which manifests itself in two oppositions: “village — city”, “collective farmer-peasant — rural intellectuals”. The author notes that the ideological and spiritual component in understanding the situation of wine drinking is associated with the expression of the author’s attitude, his worldview through the prism of the character’s opinion. It is concluded that the verbalization of Bacchic action is distinguished by figurative interpretation, the attraction of components from various spheres: the use of expressions containing somatisms, animalisms, perceptual vocabulary, verbs of physical impact, etc. When analyzing the social component of some Bacchic expressions, it is noted that the objects of wine drinking (vessels) are interpreted as subjects of interpersonal relationships
The Abramov-Rokhlin entropy addition formula for amenable group actions
Get PDFIn this note we show that the entropy of a skew product action of a countable amenable group satisfies the classical formula of Abramov and Rokhlin
The Catalytic Asymmetric Abramov Reaction
No full textThe first catalytic enantioselective Abramov reaction is described. The process is based on the utilization of a chiral disulfonimide catalyst, which efficiently avoids the difficulties encountered with metal-based catalysts. Several functionalized α-hydroxy phosphonates were synthesized in good yields and with excellent enantiomeric ratios of up to >99:1. The process was shown to be scalable and up to 1 g of starting material could be employed under mild reaction conditions
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