Biomedical subjects

Jeremy Metz

Publications and source records attributed to Jeremy Metz.

3 recordsLinked to original sources

PubMed2006

Robust entanglement through macroscopic quantum jumps.

We propose an entanglement generation scheme that requires neither the coherent evolution of a quantum system nor the detection of single photons. Instead, the desired state is heralded by a macroscopic quantum jump. Macroscopic quantum jumps manifest themselves as a random telegraph signal with long intervals of intense fluorescence (light periods) interrupted by the complete absence of photons (dark periods). Here we show that a system of two atoms trapped inside an optical cavity can be designed such that a dark period prepares the atoms in a maximally entangled ground state. Achieving fidelities above 0.9 is possible even when the single-atom cooperativity parameter is as low as 10 and when using a photon detector with an efficiency as low as eta=0.2.

Journal Article↗

PubMed2006

Bovine albumin release and degradation analysis of dicalcium phosphate dihydrate cement.

Dicalcium phosphate dihydrate (DCPD) cement was effective in our prior study as a bone morphogenetic protein-2 (BMP-2) delivery vehicle in a rat segmental defect regeneration study. In this study, we investigated the effects of liquid-to-powder (L/P) ratio on the in vitro degradation and protein release behavior of this material. The L/P ratios used in this study ranged from 0.50 to 0.83. DCPD cylinders were formed with a diameter of 1/4" and a height of 1/4". The effect of L/P on the initial compressive strength was found to be related to the porosity of the material at different L/P level. The strength of the material in phosphate buffered solution was found to degrade roughly 20% in 14 days. The relation between the final porosity and the compressive strength after degradation was modeled with Ryshkewitch equation. A liquid-to-powder ratio of 0.55, 0.7, and 0.8 was then used to fabricate samples for the protein release kinetic study. The low porosity (L/P = 0.55) group was found to have the fastest release rate, while the L/P = 0.8 group had the lowest. More then 60% of the loaded protein was released after 10 hours in all three groups with a final total release ranging between 75% and 93%. The findings suggested that the protein release profile of DCPD cements can be adjusted by the L/P ratio.

Absorbable Implants↗

PubMed2006

Effect of crosslinking density on swelling and mechanical properties of PEGDA400/PCLTMA900 hydrogels.

A biodegradable polymer network hydrogel was fabricated and characterized for neural tissue engineering purposes. The proposed hydrogel contains both hydrophobic and hydrophilic components. The hydrophobic component is a three-arm poly(e-caprolactone) maleic acid with molecular weight of 900 (PCLTMA), and the hydrophilic component is poly(ethylene glycol) diacrylate macromer (PEGDA) with molecular weight of 400. A monolithic hard gel was generated by chemical photo-crosslinking. Three different networks, with varied ratios of PEGDA to PCLTMA including 25/75, 50/50 and 75/25, were characterized by compression testing, and the swelling properties were studied in phosphate-buffered saline (PBS, 7.4). The results of this study show that a wide-range of swelling data was obtained when the composition of PEGDA to PCLTMA was changed. The compressive modulus was measured for each composition, and the 75/25 gel was stiffer than the other compositions. These basic material properties will provide preliminary data for hydrogel development to be conducted in our laboratory.

Absorption↗