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Dana Kamp

Publications and source records attributed to Dana Kamp.

3 recordsLinked to original sources

Thermodynamic control of non-equilibrium systems

We study the thermodynamic cost associated with driving systems between different non-equilibrium steady states. In particular, we combine a linear-response framework for non-equilibrium Markov systems with Lagrangian techniques to minimize the dissipation associated with driving processes. We then apply our framework to a simple toy model. Our results show several remarkable properties for the optimal protocol, such as diverging parameters and finite entropy production in the slow-driving limit.

cond-mat.stat-mech

A physical perspective on lithium therapy

Lithium salts have strong medical properties in neurological disorders such as bipolar disorder and lithium-responsive headaches. They have recently gathered attention due to their potential preventive effect in viral infections. Though the therapeutic effect of lithium was documented by Cade in the late 1940s, its underlying mechanism of action is still disputed. Acute lithium exposure has an activating effect on excitable organic tissue and organisms, and is highly toxic. Lithium exposure is associated with a strong metabolic response in the organism, with large changes in phospholipid and cholesterol expression. Opposite to acute exposure, this metabolic response alleviates excessive cellular activity. The presence of lithium ions strongly affects lipid conformation and membrane phase unlike other alkali ions, with consequences for membrane permeability, buffer property and excitability. This review investigates how lithium ions affect lipid membrane composition and function, and how lithium response might in fact be the body's attempt to counteract the physical presence of lithium ions at cell level. Ideas for further research in microbiology and drug development are discussed.

physics.bio-ph

Effects and side-effects of plasmonic photothermal therapy in brain tissue

Heat generated from plasmonic nanoparticles can be utilized in plasmonic photothermal therapy. A combination of near-infrared laser and metallic nanoparticles are compelling for the treatment of brain cancer, due to their efficient light-to-heat conversion and bio-compatibility. However, one of the challenges of plasmonic photothermal therapy is to minimize the damage of the surrounding brain tissue. The adjacent tissue can be damaged as the results of either absorption of laser light, thermal conductivity, nanoparticles diffusing from the tumor, or a combination hereof. Hence, we still lack the full understanding about the light-tissue interaction and, in particular, the thermal response. We tested the temperature change in three different porcine cerebral tissues, i.e., the stem, the cerebrum, and the cerebellum, under laser treatment. We find that the different tissues have differential optical and thermal properties and confirm the enhancement of heating from adding plasmonic nanoparticles. Furthermore, we measure the loss of laser intensity through the different cerebral tissues and stress the importance of correct analysis of the local environment of a brain tumor.

physics.med-ph