The theoretical diffraction-limit of resolution for ultrasound imaging has recently been bypassed in-vitro and in-vivo. However, in the context of ultrasound therapy, the precision of therapeutic beams remains bound to the half-wavelength limit. By combining acoustic vaporization of composite droplets and rapid ultrasound monitoring, we demonstrate that ultrasound drug-delivery can be restricte...

Endoscopic ultrasound was developed in the early 1980s to overcome the limitations of transabdominal ultrasound in imaging the gastrointestinal wall and retroperitoneum.[1] The ultrasound transducer (positioned at the endoscope tip) is applied directly against the duodenal or gastric wall. This enhances the image quality by minimizing intervening adipose tissue and air that must be traversed by...

Case 1. A 60-year-old man was treated with 72 Gy. external beam radiation therapy for Gleason score 4 3 adenocarcinoma of the prostate diagnosed by transrectal ultrasound guided biopsy. After treatment prostate speci c antigen (PSA) decreased to 1.3 ng./ml. One year later PSA had increased to 2.0 ng./ml. Transrectal ultrasound guided biopsy revealed recurrent prostatic adenocarcinoma. Salvage c...

The effect of ultrasound on the rate of fibrinolysis has been investigated using an in vitro system. Plasma or blood clots containing a trace label of 125I fibrin were suspended in plasma containing plasminogen activator and intermittently exposed to continuous wave 1-MHz ultrasound at intensities up to 8 W/cm2. Plasma clot lysis at 1 h with 1 microgram/ml recombinant tissue plasminogen activat...

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In this paper, we study the solutions of the initial-value problem (IVP) for the quasi-geostrophic equations, namely ∂tθ + u.∇θ + κ (−∆) θ = 0, on R × ]0,+∞[ , θ (x, 0) = θ0(x), x ∈ R. Our goal is to establish the existence and uniqueness of regulars solutions for the two-dimentional dissipative quasi-geostrophic equation with initial data in a Sobolev space H satisfying suitable conditions wit...

By the simple finite element method, we study the symplectic, multisymplectic structures and relevant preserving properties in some semi-linear elliptic boundary value problem in one-dimensional and two-dimensional spaces respectively. We find that with uniform mesh, the numerical schemes derived from finite element method can keep a preserved symplectic structure in one-dimensional case and a ...

We obtain the following characterization of Hilbert spaces. Let E be a Banach space whose unit sphere S has a hyperplane of symmetry. Then E is a Hilbert space iff any of the following two conditions is fulfilled: a) the isometry group Iso E of E has a dense orbit in S; b) the identity component G 0 of the group Iso E endowed with the strong operator topology acts topologically irreducible on E...