INTRODUCTION Achalasia cardia is characterized by failure of the lower esophageal sphincter to relax in response to swallowing and by an absence of peristalsis in the esophageal body. Absence of a gastric air bubble is a well known radiological finding. Pneumatic balloon dilatation results in reappearance of the gastric bubble. CASE PRESENTATION We report the case of a 43-year-old Indian man ...

Air injected into the epidural space may spread along the nerves of the paravertebral space. Depending on the location of the air, neurologic complications such as multiradicular syndrome, lumbar root compression, and even paraplegia may occur. However, cases of motor weakness caused by air bubbles after caudal epidural injection are rare. A 44-year-old female patient received a caudal epidural...

Four patients developed inferior retinal redetachment following initially successful surgery which included intraocular injection of air and sulphahexafluoride (SF6) mixture. In each case the intravitreal gas bubble produced vitreoretinal traction which opened inferior retinal breaks and led to retinal separation. Cautious use of intraocular gas is advised when bullous upper rhegmatogenous reti...

The pinch-off of an axisymmetric air bubble surrounded by an inviscid fluid is compared in four physical realizations: (i) cavity collapse in the wake of an impacting disk, (ii) gas bubbles injected through a small orifice, (iii) bubble rupture in a straining flow, and (iv) a bubble with an initially necked shape. Our boundary-integral simulations suggest that all systems eventually follow the ...

We report an experimental and theoretical study of two most critical yet still to-be-answered issues in dispensing-based nanoimprint lithography (D-NIL): air bubble formation and absorption, and discuss their impact on NIL yield and throughput. Using real-time observation via video, we found two different mechanisms for air bubble formation (feature pinning and multi-droplet encircling), and st...

BACKGROUND AND PURPOSE Injected air bubbles are a well-accepted cause of stroke during cerebral angiography. We used an in vitro model to determine the frequency of occurrence of air emboli during catheter flushing using conventional hardware and techniques. METHODS Two experimental models were used in this study. The first incorporated an in-line bubble trap. Ten members of our angiography s...

This work presents a 3D numerical study of the bubble generation process into a bubble generator obtained with the commercial Computational Fluid Dynamics solver ANSYS Fluent v15.0.7, and its comparison with experimental data reproducing the same conditions [1]. The bubble generator is formed by two perpendicular capillaries in which liquid and gas are injected at perpendicular directions into ...

When a liquid drop impacts a solid surface, air is generally entrapped underneath. Using ultrafast x-ray phase-contrast imaging, we directly visualized the profile of an entrapped air film and its evolution into a bubble during drop impact. We identified a complicated evolution process that consists of three stages: inertial retraction of the air film, contraction of the top air surface into a ...

in this research, the effect of surface roughness and bubble injection on skin friction and hydrodynamic drag force has been numerically considered. this research is based on taylor-couette flow. considered flow includes two concentric cylinders which internal cylinder is movable and external is immovable. the effective equations on the flow includes: equations of momentum, continuous, turbulen...