scholarly journals The full evolution of supernova remnants in low- and high-density ambient media

2019 ◽  
Vol 488 (1) ◽  
pp. 978-990
Author(s):  
Santiago Jiménez ◽  
Guillermo Tenorio-Tagle ◽  
Sergiy Silich
Keyword(s):  
Supernova Remnants ◽  
High Density ◽  
Radiative Cooling ◽  
Ambient Media ◽  
Reverse Shock ◽  
Rapid Fall ◽  
Wide Range ◽  
Supernova Explosions ◽  
Formation And Evolution ◽  
Shell Approximation

ABSTRACT Supernova explosions and their remnants (SNRs) drive important feedback mechanisms that impact considerably the galaxies that host them. Then, the knowledge of the SNRs evolution is of paramount importance in the understanding of the structure of the interstellar medium and the formation and evolution of galaxies. Here, we study the evolution of SNRs in homogeneous ambient media from the initial, ejecta-dominated phase, to the final, momentum-dominated stage. The numerical model is based on the Thin-Shell approximation and takes into account the configuration of the ejected gas and radiative cooling. It accurately reproduces well-known analytic and numerical results and allows one to study the SNR evolution in ambient media with a wide range of densities n0. It is shown that in the high-density cases, strong radiative cooling alters noticeably the shock dynamics and inhibits the Sedov-Taylor stage, thus limiting significantly the feedback that SNRs provide to such environments. For n0 > 5 × 105 cm−3, the reverse shock does not reach the centre of the explosion due to the rapid fall of the thermal pressure in the shocked gas caused by strong radiative cooling.

Influence of Polypropylene Fiber in Strength of Foamed Concrete

2012 ◽  
Vol 488-489 ◽  
pp. 253-257 ◽  
Author(s):  
Josef Hadipramana ◽  
Abdul Aziz Abdul Samad ◽  
Zi Jun Zhao ◽  
Noridah Mohammad ◽  
W. Wirdawati
Keyword(s):  
Tensile Strength ◽  
Mechanical Test ◽  
Polypropylene Fiber ◽  
High Density ◽  
Splitting Tensile Strength ◽  
Normal Concrete ◽  
Wide Range ◽  
Foamed Concrete ◽  
Strength Result ◽  
And Behavior

Foamed concrete is material that can be used in wide range of constructions and produced in high density. This investigation examined effect of chopped Polypropylene Fiber (PF) that mixed into admixture concerning strength of foamed concrete high density. Mechanical test were performed to measure effect of PF on improving compressive and splitting tensile strength. Result indicate that PF significantly improving compressive strength and behavior of PF where drawn into foamed concrete similarly with normal concrete. The fibrillated PF has been occurred and reduced the micro crack of matrix and prevented propagation crack growth. The presence of PF improved splitting tensile strength was not significantly. Influence of porous of foamed concrete is considered. Scanning Electron Microscope (SEM) exhibits condition microstructure of foamed concrete reinforced PF that alter microstructure, especially interfacial bonding due to PF presence.

MiR-145-5p modulates lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating β-catenin signaling in hyperlipidemia

2021 ◽  
pp. 1-7
Author(s):  
Huijun Chen ◽  
Jing Gao ◽  
Qian Xu ◽  
Dongmei Wan ◽  
Wenji Zhai ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
High Density Lipoprotein ◽  
Macrophage Polarization ◽  
Density Lipoprotein ◽  
High Density ◽  
M2 Macrophage ◽  
Cardiac Tissues ◽  
Potential Biomarker ◽  
Wide Range ◽  
M2 Macrophage Polarization

The present study aims to explore the role of microRNA 145-5p (miR-145-5p) in hyperlipidemia. Using bioinformatics tools and a wide range of function and mechanism assays, we attempted to understand the specific function and potential mechanism of miR-145-5p in hyperlipidemia. A cholesterol-enriched diet induced an increase of serum cholesterol and triacylglycerol but a decrease of serum high-density lipoprotein. MiR-145-5p level was decreased in hyperlipidemia rat models. MiR-145-5p regulated lipid metabolism by antagonizing the alteration of high-density lipoprotein, cholesterol, and triacylglycerol in serum mediated by a cholesterol-enriched diet. In mechanism, miR-145-5p directly bound with p21 protein (RAC1)-activated kinase 7 (PAK7) and negatively regulated mRNA and protein levels of PAK7 in THP-1 cells. Furthermore, miR-145-5p level was negatively associated with PAK7 level in rat cardiac tissues. Finally, overexpression of PAK7 reversed the effects of miR-145-5p on β-catenin activation and M2 macrophages polarization in THP-1 cells. In conclusion, MiR-145-5p modulated lipid metabolism and M2 macrophage polarization by targeting PAK7 and regulating β-catenin signaling in hyperlipidemia, which may provide a potential biomarker for the treatment of hyperlipidemia-induced cardiovascular diseases.

scholarly journals Infrared nebulae around bright massive stars as indicators for binary interactions

2018 ◽  
Vol 618 ◽  
pp. A110 ◽  
Author(s):  
J. Bodensteiner ◽  
D. Baade ◽  
J. Greiner ◽  
N. Langer
Keyword(s):  
Supernova Remnants ◽  
Binary Systems ◽  
Massive Stars ◽  
Space Velocity ◽  
Be Stars ◽  
Global Risk ◽  
Wide Range ◽  
Bow Shocks ◽  
Binary Evolution ◽  
Stellar Properties

Context. Recent studies show that more than 70% of massive stars do not evolve as effectively single stars, but as members of interacting binary systems. The evolution of these stars is thus strongly altered compared to similar but isolated objects. Aims. We investigate the occurrence of parsec-scale mid-infrared nebulae around early-type stars. If they exist over a wide range of stellar properties, one possible overarching explanation is non-conservative mass transfer in binary interactions, or stellar mergers. Methods. For ∼3850 stars (all OBA stars in the Bright Star Catalogue (BSC), Be stars, BeXRBs, and Be+sdO systems), we visually inspect WISE 22 μm images. Based on nebular shape and relative position, we distinguish five categories: offset bow shocks structurally aligned with the stellar space velocity, unaligned offset bow shocks, and centered, unresolved, and not classified nebulae. Results. In the BSC, we find that 28%, 13%, and 0.4% of all O, B, and A stars, respectively, possess associated infrared (IR) nebulae. Additionally, 34/234 Be stars, 4/72 BeXRBs, and 3/17 Be+sdO systems are associated with IR nebulae. Conclusions. Aligned or unaligned bow shocks result from high relative velocities between star and interstellar medium (ISM) that are dominated by the star or the ISM, respectively. About 13% of the centered nebulae could be bow shocks seen head- or tail-on. For the rest, the data disfavor explanations as remains of parental disks, supernova remnants of a previous companion, and dust production in stellar winds. The existence of centered nebulae also at high Galactic latitudes strongly limits the global risk of coincidental alignments with condensations in the ISM. Mass loss during binary evolution seems a viable mechanism for the formation of at least some of these nebulae. In total, about 29% of the IR nebulae (2% of all OBA stars in the BSC) may find their explanation in the context of binary evolution.

scholarly journals Full exploration of the giant planet population around β Pictoris

2018 ◽  
Vol 612 ◽  
pp. A108 ◽  
Author(s):  
A.-M. Lagrange ◽  
M. Keppler ◽  
N. Meunier ◽  
J. Lannier ◽  
H. Beust ◽  
...  
Keyword(s):  
Extrasolar Planets ◽  
Giant Planet ◽  
Young Stars ◽  
Giant Planets ◽  
Close Orbit ◽  
Wide Range ◽  
Detection Probabilities ◽  
Solar Type ◽  
Formation And Evolution ◽  
The One

Context. The search for extrasolar planets has been limited so far to close orbit (typ. ≤5 au) planets around mature solar-type stars on the one hand, and to planets on wide orbits (≥10 au) around young stars on the other hand. To get a better view of the full giant planet population, we have started a survey to search for giant planets around a sample of carefully selected young stars. Aims. This paper aims at exploring the giant planet population around one of our targets, β Pictoris, over a wide range of separations. With a disk and a planet already known, the β Pictoris system is indeed a very precious system for studies of planetary formation and evolution, as well as of planet–disk interactions. Methods. We analyse more than 2000 HARPS high-resolution spectra taken over 13 years as well as NaCo images recorded between 2003 and 2016. We combine these data to compute the detection probabilities of planets throughout the disk, from a fraction of au to a few dozen au. Results. We exclude the presence of planets more massive than 3 MJup closer than 1 au and further than 10 au, with a 90% probability. 15+ MJup companions are excluded throughout the disk except between 3 and 5 au with a 90% probability. In this region, we exclude companions with masses larger than 18 (resp. 30) MJup with probabilities of 60 (resp. 90) %.

scholarly journals Next-Generation Sequencing Identification and Characterization of MicroRNAs in Dwarfed Citrus Trees Infected With Citrus Dwarfing Viroid in High-Density Plantings

2021 ◽  
Vol 12 ◽  
Author(s):  
Tyler Dang ◽  
Irene Lavagi-Craddock ◽  
Sohrab Bodaghi ◽  
Georgios Vidalakis
Keyword(s):  
Next Generation Sequencing ◽  
Target Genes ◽  
Quantitative Polymerase Chain Reaction ◽  
High Density ◽  
Poncirus Trifoliata ◽  
Next Generation ◽  
Developmental Processes ◽  
Wide Range ◽  
Generation Sequencing ◽  
Citrus Trees

Citrus dwarfing viroid (CDVd) induces stunting on sweet orange trees [Citrus sinensis (L.) Osbeck], propagated on trifoliate orange rootstock [Citrus trifoliata (L.), syn. Poncirus trifoliata (L.) Raf.]. MicroRNAs (miRNAs) are a class of non-coding small RNAs (sRNAs) that play important roles in the regulation of tree gene expression. To identify miRNAs in dwarfed citrus trees, grown in high-density plantings, and their response to CDVd infection, sRNA next-generation sequencing was performed on CDVd-infected and non-infected controls. A total of 1,290 and 628 miRNAs were identified in stem and root tissues, respectively, and among those, 60 were conserved in each of these two tissue types. Three conserved miRNAs (csi-miR479, csi-miR171b, and csi-miR156) were significantly downregulated (adjusted p-value < 0.05) in the stems of CDVd-infected trees compared to the non-infected controls. The three stem downregulated miRNAs are known to be involved in various physiological and developmental processes some of which may be related to the characteristic dwarfed phenotype displayed by CDVd-infected C. sinensis on C. trifoliata rootstock field trees. Only one miRNA (csi-miR535) was significantly downregulated in CDVd-infected roots and it was predicted to target genes controlling a wide range of cellular functions. Reverse transcription quantitative polymerase chain reaction analysis performed on selected miRNA targets validated the negative correlation between the expression levels of these targets and their corresponding miRNAs in CDVd-infected trees. Our results indicate that CDVd-responsive plant miRNAs play a role in regulating important citrus growth and developmental processes that may participate in the cellular changes leading to the observed citrus dwarf phenotype.

scholarly journals A Comparison between Two Sonic Measuring Systems for Demersal Fish

1970 ◽  
Vol 27 (4) ◽  
pp. 737-742 ◽  
Author(s):  
R. G. Dowd ◽  
E. Bakken ◽  
O. Nakken
Keyword(s):  
Linear Relation ◽  
Demersal Fish ◽  
High Density ◽  
Measuring Systems ◽  
Fish Stocks ◽  
Digital Counter ◽  
Schooling Fish ◽  
Wide Range ◽  
Two Systems

Two sonic methods for estimation of abundance of fish stocks, the echo integrator and the digital counter methods, were compared on single and schooling fish in the Lofoten area of Norway during March 1969. Good correlation was obtained between the two systems for both situations, but the slopes of the regressions of integrated values on the digital counter differed significantly between low and high density fish concentrations. This suggests that the two systems treated the echo information differently, but nevertheless maintained a linear relation between themselves over a wide range of counts.

Advanced barrier and seed layer deposition enabling multiple type of TSVs integration

2019 ◽  
Vol 2019 (DPC) ◽  
pp. 000077-000103
Author(s):  
Thierry Mourier ◽  
Mathilde Gottardi ◽  
Pierre-Emile Philip ◽  
Sophie Verrun ◽  
Gilles Romero ◽  
...  
Keyword(s):  
Aspect Ratio ◽  
Seed Layer ◽  
Process Development ◽  
High Density ◽  
Process Equipment ◽  
Integration Schemes ◽  
Step Coverage ◽  
Wide Range ◽  
Silicon Thickness ◽  
Very High

TSV integration is a key technology allowing heterogeneous devices 3D integration. However, depending on the targeted application, various TSV sizes and integration schemes exist, all requesting very high aspect ratio. The most common integration is the Mid-process TSV for which aspect ratio is required to be higher than 10:1 whatever application. In the case of large interposers, silicon thickness has to be increased to limit the deformation of the substrate due to highly stressed devices. Same requirements are made by photonic interposers which use thick SOI substrate leading to high warpage during integration. In the opposite, imagers requires to save silicon surface thus reduce TSV size and keep out zone. Silicon thickness has to be kept in the 100 μm range leading then the aspect ratio of the TSV to increase. Recently, Hybrid bonding progresses allowed a new type of TSV to be introduced : High Density TSVs for imagers. In this application, micrometer range TSV have to be filled with a Silicon thickness reduction limited to 10 μm by grinding process control. In order to allow the metal filling of all those type of structures, we have developed a highly conformal barrier and seed layer processes using standard materials for easier integration. The process is based on the use of MOCVD TiN as a barrier. This material is deposited using TDMAT precursor which allows low temperature deposition (200 °C)[1] which extends also the polyvalence of the process toward polymer bonded integrations. The very high step coverage of this process, reported at more than 30% in 20:1 aspect ratio coupled to high resistance to copper diffusion allows as thin as 20 nm barrier thickness which appears relevant economically (for deposition and CMP) and for stress consideration, compared to the well known but thicker PVD TaN process. Considering seed layer, the eG3D process[2] was brought to a high maturity allowing it to be integrated in an applied material raider tool coupled to TSV filling reactors. This process, based on electrografting of copper has already proved a step coverage of more than 50% in 12:1 aspect ratio structures. The presented work shows that the same process requires only deposition parameters change to be able to fully cover 10×150 μm Mid-process TSV as well as 1×10 μm High density ones. The excellent step coverage of this process allowed as thin as 200 nm (for 10×120 μm TSVs) and 100 nm (for (1×10 μm ones) deposited thicknesses to ensure perfect coverage of the structures. eG3D process also has the ability to be used as a repair process for non-continuous widely used PVD Cu seed layers but also be deposited directly on the barrier material. These 2 layers were evaluated together in a 300mm TSV integration schemes of both 10×120 mid process and 1×10 μm High Density structures and qualified electrically. The paper will discuss the deposition process development leading to simultaneously allow copper filling of the very wide range of TSVs on the same process equipment and using the same chemicals. We will then present integration results as well as electrical test of TSV daisy chains of both mid and High density TSVs showing excellent yield for all TSV size and integration schemes.

scholarly journals High Resolution X-ray Spectra of Supernova Remnants

1983 ◽  
Vol 101 ◽  
pp. 205-211
Author(s):  
C. R. Canizares ◽  
P. F. Winkler ◽  
T. H. Markert ◽  
C. Berg
Keyword(s):  
Supernova Remnants ◽  
Abundance Ratio ◽  
Ionization Equilibrium ◽  
X Ray ◽  
Cygnus Loop ◽  
Doppler Shifts ◽  
Wide Range ◽  
Cas A ◽  
Einstein Observatory ◽  
Tycho’S Snr

We review results obtained with the Focal Plane Crystal Spectrometer (FPCS) on the Einstein Observatory. Clear evidence is found for departures from ionization equilibrium in the interior of Puppis A. This comes from the observed weakness of the forbidden lines relative to the resonance lines for the He - like triplets of O VII and Ne IX. However, it is shown that this departure from equilibrium does not alter our conclusion, based on previous FPCS results, that O and Ne are overabundant relative to Fe. The spectrum of N132D shows strong O VIII emission and very weak Fe emission, suggesting an even greater O/Fe abundance enhancement than in Puppis A. In the Cygnus Loop, the O to Ne abundance ratio is approximately solar; we have no information about Fe. The O VII triplet shows clear evidence for departures from ionization equilibrium in the Cygnus Loop. The spectrum of Tycho's SNR contains lines from ionization stages of Fe XVII through Fe XXIII and XXIV, indicating that a wide range of ionization conditions are present. Cas A and Kepler's SNR show relatively less emission from the higher ionization stages. For Tycho, we measured the strength of the strong Si XIII lines, and we find that a many-fold overabundance of Si relative to Fe is required regardless of the equilibrium state of the emitting plasma (confirming the Solid State Spectrometer results). On a separate topic, the completed analysis of X-ray Doppler shifts in Cas A suggests that the emitting material is concentrated in a ring that is inclined to the line of sight and is expanding at ~5000 km s−1.

scholarly journals Three routine methods for measuring high-density lipoprotein cholesterol compared with the Reference Method

1996 ◽  
Vol 42 (5) ◽  
pp. 738-743 ◽  
Author(s):  
N Harris ◽  
V Galpchian ◽  
N Rifai
Keyword(s):  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Dextran Sulfate ◽  
Direct Method ◽  
Density Lipoprotein ◽  
Reference Method ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
Direct Assay ◽  
Wide Range

Abstract We compared the performance of three methods for quantifying high-density lipoprotein cholesterol (HDL-C) with the Reference Method for HDL-C, using samples with a wide range of triglyceride (TG) concentrations (290-18000 mg/L). All three comparison assays-- utilizing a magnetic dextran sulfate precipitating reagent, a direct method, and a standard MgCl2-dextran sulfate reagent--were precise, with a run-to-run CV of less than or equal to 4.1%. However, the systematic error of these assays exceeded the National Cholesterol Education Program (NCEP) performance goal of less than or equal to 10% in half of the concentration ranges tested. Nevertheless, the total error of the assays generally meets the current 22% limit set by the NCEP. Although both the magnetic dextran sulfate precipitation reagent and the direct assay can be performed more rapidly than the MgCl2-dextran sulfate assay, the direct assay involves no sample preparation and requires only 4 microL of sample excluding the dead space. Although precipitation is frequently inadequate with the MgCl2-dextran sulfate reagent at TG concentrations >6000 mg/L, both the magnetic and the direct reagent show no interference from high TG concentrations as great as 18 000 mg/L.

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