3,317 research outputs found
Knots and Classical 3-Geometries
It has been conjectured by Rovelli that there is a correspondence between the
space of link classes of a Riemannian 3-manifold and the space of 3-geometries
(on the same manifold). An exact statement of his conjecture will be
established and then verified for the case when the 3-manifold is compact,
orientable and closed.Comment: 14p. type-set in AmS-TeX version 2.
Bubble transport by electro-magnetophoretic forces at anode bottom of aluminium cells
Electrically conducting and nonconducting particles and bubbles experience additional forcing in a liquid which carries electric current. These so called electro-magnetophoretic forces are well known in metallurgical applications, like metal purification in vacuum-arc remelting, electro-slag processes, impurity removal or
concentration change in special castings. However, the effect of electro-magnetophoretic forces has never been considered for aluminium cells where the gas bubbles evolving in the liquid electrolyte are surrounded by an electric current and significant magnetic fields. We present models to estimate the effect of electric current flow in the vicinity of the bubbles and the additional
pressure distribution resulting from the magnetic forces in the surrounding liquid electrolyte. According to the estimates, this force becomes important for bubbles exceeding 2 mm in size, and could be sufficient to overcome the typical drag force associated with electrolyte flow thereby opposing motion of the bubble along the base of the anode when it is inclined at a slight angle. The effect
could explain certain features of the anode effect onset.
Mathematical models and numerical results are presented and a further implementation in the general MHD code for the aluminium cell design is discussed
Minimally invasive glaucoma surgery: comparison of iStent with iStent inject in primary open angle glaucoma
Importance:Minimally invasive glaucoma surgery has gained significant traction in recent years. This study evaluates the firstâ and secondâgeneration trabecular microâbypass stents âiStentâ and âiStent injectâ.Background:To evaluate and compare the effect of a single iStent and double iStent inject in primary open angle glaucoma.Design:Prospective comparative case series.Participants:Primary open angle glaucoma patients undergoing trabecular microâbypass stent insertion combined with cataract surgery.Methods:Baseline demographic information, preoperative, intraoperative and postoperative outcomes including intraocular pressure (IOP), visual acuity, reliance on glaucoma medication and complications were collected and analysed.Main Outcome Measures:Primary, secondary and tertiary outcome measures were consecutively defined as an IOP of â€18âmmHg with zero medications, an IOP of â€18âmmHg with reduced medications or a 20% reduction in IOP with or without medication.Results:The study comprised 145 eyes in the iStent and 100 eyes in the iStent inject group. At 12âmonths, 56.0% of the iStent and 51.3% of the iStent inject eyes had achieved primary success and 63.1% and 57.7% secondary success. The mean postoperative IOP was 16.6 mmHg in iStent and 16.9 mmHg in iStent inject. Survival analysis demonstrated a greater incidence of failure in the iStent inject beyond 5 months.Conclusions and Relevance:Both trabecular microâbypass stents in this study were effective in reducing IOP and the burden of medication when combined with cataract surgery. There was no statistically significant difference between the two groups across our outcome measures although the iStent inject required earlier recommencement of medications for optimal IOP control
Myc inhibition impairs autophagosome formation
Autophagy, a major clearance route for most long-lived proteins and organelles, has long been implicated in cancer development. Myc is a proto-oncogene often found to be deregulated in many cancers, and thus presents as an attractive target for design of cancer therapy. Therefore, understanding the relationship between anti-Myc strategies and autophagy will be important for development of effective therapy. Here we show that Myc depletion inhibits autophagosome formation and impairs clearance of autophagy substrates. Myc suppression has an inhibitory effect on autophagy via reduction of JNK1 and Bcl2 phosphorylation. Additionally, the decrease in JNK1 phosphorylation observed with Myc knockdown is associated with a reduction in ROS production. Our data suggest that targeting Myc in cancer therapy might have the additional benefit of inhibiting autophagy in the case of therapy resistance associated with chemotherapy-induced autophagy
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