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H Bruus

Publications and source records attributed to H Bruus.

5 recordsLinked to original sources
PubMed2006

Frequency response in surface-potential driven electrohydrodynamics.

Using a Fourier approach we offer a general solution to calculations of slip velocity within the circuit description of the electrohydrodynamics in a binary electrolyte confined by a plane surface with a modulated surface potential. We consider the case with a spatially constant intrinsic surface capacitance where the net flow rate is, in general, zero while harmonic rolls as well as time-averaged vortexlike components may exist depending on the spatial symmetry and extension of the surface potential. In general, the system displays a resonance behavior at a frequency corresponding to the inverse time of the system. Different surface potentials share the common feature that the resonance frequency is inversely proportional to the characteristic length scale of the surface potential. For the asymptotic frequency dependence above resonance we find a omega(-2) power law for surface potentials with either an even or an odd symmetry. Below resonance we also find a power law omega(alpha) with alpha being positive and dependent of the properties of the surface potential. Comparing a tanh potential and a sech potential we qualitatively find the same slip velocity, but for the below-resonance frequency response the two potentials display different power-law asymptotics with alpha=1 and alpha approximately 2, respectively.

Journal Article↗
PubMed2003

Individualized medicine - implementation of pharmacogenetic diagnostics in antidepressant drug treatment of major depressive disorders.

Antidepressant drug therapy is characterized by a high rate of therapeutic failure. There is increasing evidence that genetic factors are contributing to the inter-individual variability in antidepressant drug response. Genetic variability is described in both the pharmacokinetic part of drug action as well as in pharmacodynamic structures mediating drug effects. Genetic polymorphisms in drug metabolizing enzymes are well characterized and have large effects on oral clearances or elimination half-lives of antidepressant drugs. These differences can be compensated by adapting the individual dose to genotype in addition to other factors such as gender, weight, age, liver and kidney function. On the part of drug action, genetic variability is described in molecular structures of antidepressant effects. Several studies on response of antidepressants have revealed influences of polymorphisms in neurotransmitter receptors and transporters changing sensitivity of patients to treatment with antidepressants; however, results were often contradictory. A pharmacogenomic approach to individualize antidepressant drug treatment is recommended to be based on several levels: 1) identifying and validating the candidate genes involved in drug-response; 2) providing therapeutic guidelines; and 3) developing a pharmacogenetic test-system for bedside-genotyping.

Age Factors↗