Biomedical subjects

D F Lee

Publications and source records attributed to D F Lee.

14 recordsLinked to original sources

PubMed2006

High-performance high-TC superconducting wires.

We demonstrated short segments of a superconducting wire that meets or exceeds performance requirements for many large-scale applications of high-temperature superconducting materials, especially those requiring a high supercurrent and/or a high engineering critical current density in applied magnetic fields. The performance requirements for these varied applications were met in 3-micrometer-thick YBa2Cu3O(7-delta) films epitaxially grown via pulsed laser ablation on rolling assisted biaxially textured substrates. Enhancements of the critical current in self-field as well as excellent retention of this current in high applied magnetic fields were achieved in the thick films via incorporation of a periodic array of extended columnar defects, composed of self-aligned nanodots of nonsuperconducting material extending through the entire thickness of the film. These columnar defects are highly effective in pinning the superconducting vortices or flux lines, thereby resulting in the substantially enhanced performance of this wire.

Journal Article↗

PubMed2000

A baculovirus superinfection system: efficient vehicle for gene transfer into Drosophila S2 cells.

The baculovirus expression vector system is considered to be a safe, powerful, but cell-lytic heterologous protein expression system in insect cells. We show here that there is a new baculovirus system for efficient gene transfer and expression using the popular and genetically well-understood Drosophila S2 cells. The recombinant baculovirus was constructed to carry an enhanced green fluorescent protein under the control of polyhedrin promoter as a fluorescent selection marker in the Sf21 cell line. Recombinant baculoviruses were then used to transduce S2 cells with target gene expression cassettes containing a Drosophila heat shock protein 70, an actin 5C, or a metallothionein promoter. Nearly 100% of the S2 cells showed evidence of gene expression after infection. The time course for the optimal protein expression peaked at 24 to 36 h postinfection, which is significantly earlier than a polyhedrin-driven protein expression in Sf21 cells. Importantly, S2 cells did not appear to be lysed after infection, and the protein expression levels are comparable to those of proteins under the control of polyhedrin promoter in several lepidopteran cell lines. Most surprisingly, S2 cells permit repetitive infections of multiple baculoviruses over time. These findings clearly suggest that this baculovirus-S2 system may effect the efficient gene transfer and expression system of the well-characterized Drosophila S2 cells.

Animals↗

PubMed1999

Severe intrapulmonary shunting associated with metastatic carcinoid.

A 37-year-old woman with a 10-year history of metastatic carcinoid presented to her oncologist with increased dyspnea. Further evaluation revealed hypoxemia and intrapulmonary vasodilatation. We describe a case of hepatopulmonary-like physiology associated with metastatic carcinoid in a patient with intact liver function. To our knowledge, this is the first documented case of intrapulmonary shunting and hepatopulmonary-like physiology associated with metastatic carcinoid.

Adult↗

PubMed1995

Mitral valve prolapse causing severe mitral regurgitation in a patient with absent right pulmonary artery.

A 33-year-old man was investigated for dyspnea on exertion and the presence of a pansystolic murmur. Physical examination revealed dextrocardia confirmed by chest radiograph, which also showed oligemic right lung field. Subsequent cardiac catheterization revealed secundum atrial septal defect, persistent left sided superior vena cava, and severe mitral valve prolapse causing severe mitral regurgitation with pulmonary hypertension. The right pulmonary artery was absent. It is the first report of the association between severe mitral valve prolapse and absent right pulmonary artery.

Adult↗

PubMed1986