Linear and nonlinear convection in a rotating annular cylinder, under experimental boundary conditions, heated from below and rotating about a vertical axis are investigated. In addition to the usual physical parameters such as the Rayleigh and Taylor number, an important geometric parameter, the ratio of the inner to outer radius, enters into the problem. For intermediate ratios, linear stability analysis reveals that there exist two countertraveling convective waves which are nonlinearly significant: a retrograde wave located near the outer sidewall and a prograde wave adjacent to the inner sidewall. Several interesting phenomena of nonlinear convection are found: (i) tempospatially modulated countertraveling waves caused by an instability of the Eckhaus-Benjamin-Feir type, (ii) destructive countertraveling waves in which the existence or disappearance of the prograde wave is determined by its relative phase to the retrograde wave, and (iii) a saddle-node-type bifurcation in which the prograde wave takes an infinite amount of time to pass over the retrograde wave.
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Nat Commun
December 2024
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Currently there are no effective treatments for an array of neurodegenerative disorders to a large part because cell-based models fail to recapitulate disease. Here we develop a reproducible human iPSC-based model where laser axotomy causes retrograde axon degeneration leading to neuronal cell death. Time-lapse confocal imaging revealed that damage triggers an apoptotic wave of mitochondrial fission proceeding from the site of injury to the soma.
View Article and Find Full Text PDFEur Heart J Case Rep
December 2024
Department of Cardiology, Hyogo Prefectural Awaji Medical Center, 1-1-137 Shioya, Sumoto 656-0021, Japan.
Background: Atrial standstill is characterized by the absence of atrial activity. We report a case of a patient with extensive atrial fibrosis who underwent electrophysiologic study (EPS) and electroanatomical mapping (EAM) to identify surviving atrial sites amenable for pacemaker lead implantation.
Case Summary: A 72-year-old man with persistent atrial fibrillation (AF) and atrial functional mitral regurgitation/tricuspid regurgitation (MR/TR) underwent a Cox-Maze surgery, mitral and tricuspid valve repair, and biatrial plication.
Med Rev (2021)
December 2024
Department of Gastroenterology, Changhai Hospital , Naval Medical University, Shanghai, China.
Chronic pancreatitis (CP) is characterized by irreversible destruction of pancreatic parenchyma, inflammatory cell infiltration and progressive fibrosis of pancreatic tissue. Obstruction of pancreatic duct by pancreatic stone is the common pathological change in the course of CP with the incidence of over 50 % at the diagnosis of CP. These ductal stones would cause pancreatic parenchymal hypertension and local ischemia, which was eventually followed by recurrent episodes of painful pancreatitis or other manifestations of pancreatic exocrine and endocrine insufficiency.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
December 2024
Applied Physics Laboratory, Johns Hopkins University, MP3-E169, 11100 Johns Hopkins Road, Laurel, MD 20723, USA.
Triton, the largest satellite of Neptune, is in a retrograde orbit and is likely a captured Kuiper Belt Object (KBO). Triton has a mean density of only 2.061 gm/cm and is therefore believed to have a 250-400 km thick hydrosphere.
View Article and Find Full Text PDFHepatobiliary Pancreat Dis Int
November 2024
Department of Gastroenterology, Changhai Hospital, Naval Medical University, Shanghai 200433, China; Shanghai Institute of Pancreatic Diseases, Shanghai 200000, China; Changhai Clinical Research Unit, Changhai Hospital, Naval Medical University, Shanghai 200433, China. Electronic address:
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