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The physics and astrophysics of Type Ia supernova explosions

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Frontiers of physics 2013年第2期8卷 111-115页

作者： Mike Guidry Bronson messer Dcparlment of Physics and Astronomy University of Tennessee. KnoxvilleUSA TN 37996 Physies Division Oak Ridge National Laboratory Oak RidgeUSA TN 37830 Computer Science and Mathematics Division Oak Ridge National Laboratory Oak RidgeUSA TN 37830 National Center for Computational Sciences Oak Ridge National Laboratory Oak Ridgv USA TN 37831

Asupernowt is a transient astronomical event of spectacular peak brightness that is associ-a ted with an exploding star. Supernovae exhibit a range of observational characteristics that historically h^ts led to a rich set of classsifications and sub-clmssifications. Despite the complex- ity of the obscrwttionally-based supernova, taxonomy, we now believe that all supernovae are caused by just one of two basic inechanisms：（i） the collapse of the core of a inassive star late in its litb, or （ii） a runaway thermonuclear explosion in a white dwarf. The former is terlned tile cor^-collapsc mechanism, and is powered by gravitational energy

关键词： astrophysics an exploding star the observationally-based

Tribological performance and microstructural evolution ofα-brass alloys as a function of zinc concentration

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Friction 2020年第6期8卷 1117-1136页

作者： Zhilong LIU Philipp messer-HANNEMANN Stephan LAUBE Christian GREINER Institute for Applied Materials(IAM) Karlsruhe Institute of Technology(KIT)Karlsruhe 76131Germany KIT IAM-CMS MikroTribologie CentrumμTC Karlsruhe 76131Germany

Tailoring a material's properties for low friction and little wear in a strategic fashion is a long-standing goal of materials *** deformation plays a major role when metals are employed in a sliding contact;therefore,the effects of stacking fault energy and mode of dislocation glide need to be ***,we investigated how a decrease in the stacking fault energy affects friction,wear,and the ensuing sub-surface microstructure *** samples with increasing zinc concentrations of 5,15,and 36 wt%were tested in non-lubricated sphere-on-plate contacts with a reciprocating linear tribometer against Si3N4 *** the sliding distance from 0.5(single trace)to 5,000 reciprocating cycles covered different stages in the lifetime of a sliding *** the results among the three alloys revealed a profound effect of the zinc concentration on the tribological ***15 and CuZn36 showed similar friction and wear results,whereas CuZn5 had a roughly 60%higher friction coefficient(COF)than the other two ***15 and CuZn36 had a much smaller wear rate than *** dislocation motion in CuZn5 and CuZn15 allowed for dislocation self-organization into a horizontal line about 150 nm beneath the contact after a single trace of the *** feature was absent in CuZn36 where owing to planar dislocation slip band-like features under a 45°angle to the surface were *** results hold the promise to help guide the future development of alloys tailored for specific tribological applications.

关键词： brass tribology sliding contact microstructure stacking fault energy electron microscopy

Significance of intercellular communication for neurodegenerative diseases

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Neural Regeneration Research 2022年第5期17卷 1015-1017页

作者： Hilal Cihankaya Carsten Theiss veronika Matschke Ruhr University Bochum Medical FacultyInstitute of AnatomyDepartment of CytologyBochumGermany International Graduate School of Neuroscience(IGSN) Ruhr-University BochumBochumGermany

The nervous system is a highly complex organization composed of its basicunit,the neuronal cells,and specialized supporting cells,the glial *** main glial cells in the central nervous system(CNS)are astrocytes,microgl... 详细信息

关键词： cytes diseases degenerative

Geometrical Deposits on Microstructured Surfaces

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Journal of Bionic Engineering 2020年第4期17卷 851-865页

作者： veronika Kubyshkina Daniel Orejon Coinneach Mackenzie Dover Khellil Sefiane University of Edinburgh School of EngineeringKings BuildingsMayfield RoadEdinburghEH93JLUK Oden Institute for Computational Engineering and Sciences The University of Texas at AustinTexas TX 78712USA Tianjin Key Lab of Refrigeration Technology Tianjin University of CommerceTianjin 300134China

Research into evaporating droplets on patterned surfaces has grown exponentially,since the capacity to control droplet morphology has proven to have significant technological utility in emerging areas of fundamental research and industrial ***,we incorporate two interest domains-complex wetting patterns of droplets on structured surfaces and the ubiquitous coffee-ring phenomenon of nanofluids containing dispersed aluminium oxide *** lay out the surface design criteria by quantifying the effect of pillar density and shape on the wetting footprint of droplets,yielding complex polygon droplet *** work is not constrained to pure liquids only,as we delve into the shape selection of particle-laden droplets of different *** visualise the deposition patterns through microscopy on surfaces exhibiting different features and further establish the ordering of particles on microscale surface *** a high nanofluid concentration,we observe intriguing self-assembly of particles into highly ordered intricate *** collective findings of this work have the potential to enhance many industrial technologies,particularly attractive for high performance optical and electrical devices.

关键词： geometrical wetting tuneable surface topography nanosuspensions deposition patterns particle assembly

Oxidative stress: the lowest common denominator of multiple diseases

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Neural Regeneration Research 2019年第2期14卷 238-241页

作者： veronika Matschke Carsten Theiss Johann Matschke Institute of Anatomy Department of Cytology Ruhr University Bochum Institute of Cell Biology (Cancer Research) University of Duisburg-Essen University Hospital Essen

Oxygen is essential to the human life and life of all aerobic organisms. The complete oxidation of nutrients for the biological energy supply is one of the most important prerequisites for the formation of higher life forms. However, cells that benefit from oxidative respiration also suffer from reactive oxygen species because they adapted to oxygen as an energy source. Healthy cells balance the formation and elimination of reactive oxygen species thereby creating and keeping reactive oxygen species-homeostasis. When the concentration of free radicals exceeds a critical level and homeostasis is disturbed, oxidative stress occurs leading to damage of multiple cellular molecules and compartments. Therefore, oxidative stress plays an important role in the physiology and pathology of various diseases. Often, the antioxidant protection system becomes pathologically unbalanced in the genesis of several diseases, leading to functional losses of the organism, as in the case of amyotrophic lateral sclerosis, or cells develop metabolic mechanisms to use this system as protection against external influences, such as in the case of glioblastoma cells. Either way, understanding the underlying deregulated mechanisms of the oxidative protection system would allow the development of novel treatment strategies for various diseases. Thus, regardless of the direction in which the reactive oxygen species-homeostasis disequilibrate, the focus should be on the oxidative protection system.

关键词： neurodegenerative disease amyotrophic lateral sclerosis cancer glioblastoma reactive oxygen species metabolism antioxidant protection system

Chronic active and atrophic gastritis as significant contributing factor to the development of gastric cystica profunda

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World Journal of Gastroenterology 2024年第17期30卷 2308-2310页

作者： veronika Papp Pál Miheller Department of Surgery Transplantation and GastroenterologySemmelweis UniversityBudapest 1082Hungary

Gastric cystica profunda(GCP)is an uncommon but underestimated gastric *** precancerous potential determines its *** addition to previous mucosa injury due to operations,biopsy or polypectomy,chronic active and atrophic gastritis may also lead to the development of *** carefully examining the stomach and taking biopsy samples from the susceptible regions,the stage of atrophy can be *** atrophic gastritis is a risk factor for cancer evolvement and it can also contribute to GCPs *** frequently occur close to early gastric cancers(EGCs)or EGC can arise from the cystic *** resection is an effective and minimally invasive treat-ment in GCP.

关键词： Gastric cystica profunda Chronic active gastritis Atrophic gastritis Operative Link for Gastritis Assessment staging Early gastric cancer Endoscopic resection

Forest Disturbance Enhanced the Activity of Epedaphic Collembola in Windthrown Stands of the High Tatra Mountains

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Journal of Mountain Science 2014年第2期11卷 449-463页

作者： veronika URBANOVIOVá Dana MIKLISOVá Lubomír KOVá Institute of Biology and Ecology Faculty of Science P.J. Safárik UniversityMoyzesova 11 Kosice 04001 Slovakia Institute of Parasitology Slovak Academy of SciencesHlinkova 3 Kosice 04001 Slovakia

The study aimed to assess the response of ep- and hemiedaphic Collembola communities(activity, richness, community structure) to a disturbance, the subsequent management regime and to the season(summer, winter) in a High Tatra Mountains spruce forest destroyed by a *** and clear-cut resulted in an initial increase in the activity of Collembola inhabiting open areas,opportunistic or generalist species, while forest specialists diminished in numbers or *** results indicated that treatment with nonextracted fallen trees(NEX) provided a better chance for forest species to survive compared with their survival in open habitats of extracted(EXT) and wildfire(FIR) treatments. Great species' potential of NEX treatment was indicated by Chao2 estimator and activity/species rarefaction curves. Communities of NEX treatment were more similar to the reference(REF) treatment, documented by ordination and cluster analyses. Thus, leaving fallen timber after a windthrow to natural process of succession is suitable for survival of forest species and maintenance of diversity in forests restoration than timber *** structure in wildfire(FIR) stands was the most dissimilar to the other treatments. Most of the species trapped in this treatment belonged to hemiedaphic life forms, while the activity of larger epedaphic species diminished. In contrast, the highest number of trapped Collembola in EXT treatment was connected with the larger-bodied epigeic species with fast dispersal ability. The trapping period affected both the number of individuals and species richness;Collembola activity and species diversity in the individual treatments were lower in winter compared with the summer period. Several species increased activity during the winter period, namely Folsomia penicula, Friesea mirabilis, F. truncata, Hypogastrura socialis and Protaphorura aurantiaca.

关键词： Wildfire Windstorm Clear-cutting Collembola Spruce forest

Decomposition of labile and recalcitrant coniferous litter fractions affected by temperature during the growing season

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Journal of Forestry Research 2020年第4期31卷 1115-1121页

作者： veronika Jílková Kristyna Dufková Tomás Cajthaml Na Sádkách 7CeskéBudějovice 37005Czech Republic Faculty of Science Masaryk UniversityKotlárská267/2Brno 61137Czech Republic Institute for Environmental Studies Charles University in PragueBenátská2Prague 12801Czech Republic Institute of Microbiology Czech Academy of SciencesVídeňská1083Prague 14220Czech Republic

Temperate coniferous forest soils are considered important sinks of soil organic carbon(C).Fresh C inputs may,however,affect soil microbial activity,leading to increased organic matter decomposition and carbon dioxide *** consists of labile and recalcitrant fractions which are thought to be utilized by distinct microbial communities and at different rates during the growing *** this study,we incubated the whole litter(LC+RC),the labile(LC)and the recalcitrant(RC)fractions with the coniferous soil at two temperatures representing spring/autumn(10℃)and summer(20℃)for one *** respiration and microbial community composition were regularly determined using phospholipid fatty acids as *** LC fraction greatly increased soil respiration at the beginning of the incubation period but this effect was rather *** effect of the RC fraction persisted longer and,together with the LC+RC fraction,respiration increased during the whole incubation *** of the RC fraction was more strongly affected by higher temperatures than decomposition of the more labile fractions(LC and LC+RC).However,when we consider the relative increase in soil respiration compared to the dH2 O treatment,respiration increased more at a lower temperature,suggesting that available C is more important for microbial metabolism at lower *** C was added only once in our study,no changes in microbial community composition were detected,possibly because the microbial community is adapted to relatively low amounts of additional C such as the amounts naturally found in litter.

关键词： Temperate forest Picea abies Soil respiration Hot water-extractable carbon PLFA (phospholipid fatty acids)

A phantom gallbladder on endoscopic retrograde cholangiopancreatography

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World Journal of Gastroenterology 2007年第46期13卷 6274-6276页

作者： Jeremy Rochester Caroline K messer Bruce P Reiter Mark A Korsten Gastroenterology and Radiology Programs James J.Peters VA Medical CenterBronxNY 10468Montefiore Medical CenterBronxNYMount Sinai School of MedicineNew YorkNY and Albert Einstein College of MedicineBronxNew York 10468United States

Various complications have been related to laparoscopic cholecystectomy but most occur shortly after the procedure. In this report, we present a case with very late complications in which an abscess developed within the gallbladder fossa 6 years after laparoscopic cholecystectomy. The abscess resolved after treatment with CT-guided extrahepatic aspiration. However, 4 years later, an endoscopic retrograde cholangiopancreatography （ERCP） performed for choledocholithiasis demonstrated a “gallbladder” which communicated with the common bile duct via a patent cystic duct. This unique case indicates that a cystic duct stump may communicate with the gallbladder fossa many years following cholecystectomy.

关键词： Laparoscopic cholecystectomy Complication Abscess Gallbladder Endoscopic retrograde cholangio-pancreatography