Biomedical subjects

Richard S Yoon

Publications and source records attributed to Richard S Yoon.

3 recordsLinked to original sources

PubMed2006

Publication rates of scientific presentations at the American Association of Hip and Knee Surgeons annual meetings from 1996 to 2001.

National orthopedic subspecialty meetings are a research forum where volumes of investigations are presented after a peer-reviewed selection process. The objective of this investigation was to determine the publication rate of recent scientific presentations presented at the American Association of Hip and Knee Surgeons (AAHKS) annual meetings. From 1996 to 2001, 168 (58%) of 292 podium abstracts presented at meetings were published. The average time to publication was 21.7 +/- 14.7 months. Three major orthopedic journals constituted 89% of the publications. The 58% publication rate for AAHKS ranks as one of the higher rates for orthopedic specialty meetings and validates the selection process for abstracts presented. In addition, AAHKS meetings are an excellent source for a wide array of quality research and scientific information.

Bibliometrics↗

PubMed2003

Measurement of thoracic current flow in pigs for the study of defibrillation and cardioversion.

Although defibrillation has been in clinical use for more than 50 years, the complete current flow distribution inside the body during a defibrillation procedure has never been directly measured. This is due to the lack of appropriate imaging technology to noninvasively monitor the current flow inside the body. The current density imaging (CDI) technique, using a magnetic resonance (MR) imager, provides a new approach to this problem [Scott et al. (1991)]. CDI measures the local magnetic field generated by the current and calculates the current density by computing its curl. In this study, CDI was used to measure current density at all points within a postmortem pig torso during an electrical current application through defibrillation electrodes. Furthermore, current flow information was visualized along the chest wall and within the chest cavity using streamline analysis. As expected, some of the highest current densities were observed in the chest wall. However, current density distribution varied significantly from one region to another, possibly reflecting underlying heterogeneous tissue conductivity and anisotropy. Moreover, the current flow analysis revealed many complex and unexpected current flow patterns that have never been observed before. This study has, for the first time, noninvasively measured the volume current measurement inside the pig torso.

Animals↗

PubMed2002

Why does MTR change with neuronal depolarization?

T1 and T2 relaxation, and magnetization transfer (MT) of the rat brain were measured during experimentally induced spreading depression (SD). All measured MR parameters changed during SD: T1 relaxation increased by approximately 13%, whereas the T2 increase was substantially larger (88%). MT results showed an MT ratio (MTR) decrease of 9%. The lack of change in the MT exchange rate indicated that the MT processes between water and macromolecular protons are not affected by neuronal depolarization. The observed decrease in MTR was only caused by changes in T1 and T2 relaxation.

Animals↗