Biomedical subjects

SK Kim

Publications and source records attributed to SK Kim.

At least 19 recordsLinked to original sources

PubMed2000

Direct observation of self-focusing with subdiffraction limited resolution using near-field scanning optical microscope

The self-focusing effect in As2S3 glass has been studied using a near-field scanning optical microscope. Optical images of fine features in the self-focused beam were directly measured at the self-focus with approximately 100 nm spatial resolution. Because of the unusually large nonlinear refractive index at 690 nm, filaments with minimum size of 0.3 &mgr;m were observed in a 1.6 mW beam propagating through the 1.7 &mgr;m thin film. A qualitative analysis of our experimental results is presented. We show that nonparaxiality is responsible for arresting self-focusing, as predicted by recent theories.

Journal Article↗

PubMed2000

Resonant formation of d&mgr;t molecules in deuterium: An atomic beam measurement of muon catalyzed dt fusion

Resonant formation of d&mgr;t molecules in collisions of muonic tritium ( &mgr;t) on D2 was investigated using a beam of &mgr;t atoms, demonstrating a new direct approach in muon catalyzed fusion studies. Strong epithermal resonances in d&mgr;t formation were directly revealed for the first time. From the time-of-flight analysis of 2036+/-116 dt fusion events, a formation rate consistent with 0.73+/-(0.16)(meas)+/-(0.09)(model) times the theoretical prediction was obtained. For the largest peak at a resonance energy of 0.423+/-0.037 eV, this corresponds to a rate of (7.1+/-1.8)x10(9) s(-1), more than an order of magnitude larger than those at low energies.

Journal Article↗

PubMed2000

Growth with surface curvature on quenched potentials

A discrete growth model driven by the Laplacian of the surface curvature in quenched random media is discussed. The interface width W at the saturated regime obeys scaling W approximately Lalpha with alpha approximately 2.3, where L is the system size. Starting from an initial sine wave condition of a selected wavelength, we measure an autocorrelation function, and obtain the dynamic critical exponent z approximately 3.1. The model is expected to be described by the quenched Mullins-Herring equations.

Journal Article↗

PubMed1999

Complementary DNA Encoding nm23/NDP Kinase Gene from the Korean Tiger Shark Scyliorhinus torazame.

: A new tumor suppressor gene, snm23, homologous to the gene for human nucleoside diphosphate kinase nm23/NDP was first cloned from Korean tiger shark (Scyliorhinus torazame) skin lambda ZAP-II complementary DNA library. The gene (named snm23) containing the tumor metastasis suppressor protein was sequenced. The nucleotide and deduced amino acid sequences of snm23 revealed an open reading frame of 450 bp that corresponded to a protein of 150 amino acid residues, with a calculated molecular mass of 16.8 kDa. Sequence comparison of snm23 with nm23/NDP kinases was performed. In order to determine tissue specificity, reverse transcription-polymerase chain reaction was used. The expression of snm23/NDP kinase was detected in tissues from skin, cartilage, and liver of Korean tiger shark.

Journal Article↗

PubMed1996