Biomedical subjects

G Rosenblum

Publications and source records attributed to G Rosenblum.

13 recordsLinked to original sources

PubMed2005

Adiabatic mode multiplexer for evanescent-coupling-insensitive optical switching.

A novel adiabatic mode multiplexer enables a 2 x 2 optical switch whose operation does not depend on accumulated phase due to evanescent coupling between waveguides. The adiabatic mode multiplexer has a negligible insertion loss over C+L bands and modal cross talk better than -40 dB for any polarization state. Mode multiplexing is achieved by adiabatic transition from the fundamental mode of the single-mode waveguide to the higher mode of the multimode waveguide. Experimental measurement results for a device realized in silica-on-silicon technology are presented. By directly measuring the nonadiabatic transition probability, we show that the adiabatic mode multiplexer operates in the Landau-Zener regime.

Journal Article↗

PubMed2001

Ribosomal crystallography: from poorly diffracting microcrystals to high-resolution structures.

The cellular organelles translating the genetic code into proteins, the ribosomes, are large, asymmetric, flexible, and unstable ribonucleoprotein assemblies, hence they are difficult to crystallize. Despite two decades of intensive effort and thorough searches for suitable sources, so far only three crystal types have yielded high-resolution structures: two large subunits (from an archaean and from a mesophilic eubacterium) and one thermophilic small subunit. These structures have added to our understanding of decoding, have revealed dynamic aspects of the biosynthetic process, and have indicated the strategies adopted by ribosomes for interacting between themselves as well as with inhibitors, factors and substrates.

Archaea↗

PubMed1984

Computed tomography of diverticulitis.

Six cases of diverticulitis were studied by means of pelvic computed tomography (CT) and contrast enema. CT is effective in defining the intramural and extracolonic component of diverticulitis; abscess formation in the extracolonic space resulted in consistent changes in the contour of the opacified urinary bladder. Inflammatory extracolonic masses were imaged on CT as low or mixed-attenuation lesions frequently containing pockets of gas. Bladder wall thickening and edema, as well as contour asymmetry of the opacified and distended bladder, were reliable indicators of pericolonic or extracolonic extension of diverticular disease. Contrast enema and sigmoidoscopy are inherently limited in the evaluation of diverticulitis; CT of the pelvis reveals secondary changes outside the mucosa and bowel wall, CT directly images the inflammatory mass and associated changes in pelvic anatomic relationships. CT findings of pelvic inflammatory mass are not specific for abscess of diverticular origin; however, CT interpretation is reliable and confident since it is directed by the supporting findings on contrast enema. Integrated study by CT and contrast enema effectively defines the extent of disease in patients with diverticulitis. Summary evaluation of these studies has a serious impact on the choice of medical or surgical management.

Aged↗

PubMed1984