Theory of multiwave mixing and decoherence control in qubit array system

We develop a theory to analyze the decoherence effect in a charged qubit array system with photon echo signals in the multiwave mixing configuration. We present how the decoherence suppression effect by the {\it bang-bang} control with the $\pi$ pulses can be demonstrated in laboratory by using a bulk ensemble of exciton qubits and optical pulses whose pulse area is even smaller than $\pi$. Analysis is made on the time-integated multiwave mixing signals diffracted into certain phase matching directions from a bulk ensemble. Depending on the pulse interval conditions, the cross over from the decoherence acceleration regime to the decoherence suppression regime, which is a peculiar feature of the coherent interaction between a qubit and the reservoir bosons, may be observed in the time-integated multiwave mixing signals in the realistic case including inhomogeneous broadening effect. Our analysis will successfully be applied to precise estimation of the reservoir parameters from experimental data of the direction resolved signal intensities obtained in the multiwave mixing technique.Comment: 19 pages, 11 figure

Studies on the mechanism of subcellular distribution of basic drugs based on their lipophilicity

金沢大学医学部附属病院薬剤部This paper described the studies on the mechanism of subcellular distribution of lipophilic weak bases. Although the tissue distribution of basic drugs appeared to decrease with time simply in parallel with their plasma concentration, their subcellular distribution in various tissues exhibited a variety of patterns. Basic drugs were distributed widely in various tissues, but were concentrated in lung granule fraction, where their accumulation was dependent on their lipophilicity and lysosomal uptake. As the plasma concentration of drugs decreased after maximum level, the contribution of lysosomes to their subcellular distribution increased. The uptake of the basic drugs into lysosomes depended both on their intralysosomal pH and on the drug lipophilicity. As the lipophilicity of the basic drugs increased, they accumulated more than the values predicted from the pH-partition theory and raised the intralysosomal pH more potently, probably owing to their binding with lysosomal membranes with or without additional intralysosomal aggregation. These phenomena should be considered as a basis of drug interaction in clinical treatments

Send reprint requests to: A PHYSIOLOGICALLY BASED PHARMACOKINETIC MODEL FOR (-)-QUINUCLIDINYL BENZYLATE USING NONLINEAR IRREVERSIBLE TISSUE BINDING PARAMETERS IN RATS

ABSTRACT: The disposition characteristics of (-)

Determination of a pain substance produced by the photodegradation of dacarbazine

The anticancer drug, dacarbazine, is known to be photosensitive, and its photodegradation products have been pointed out as the causes of side effects including local venous pain of injection site. In this study, we attempted to clarify the causative substance of pain after photodegradation of dacarbazine. We synthesized five photodegradation products of dacarbazine; dimethylamine, 5-diazoimidazole-4-carboxamide (Diazo-IC), 4-carbamoylimidazolium-5-olate, 4-carbamoyl-2-(4-carbamoylimidazol-5-ylazo) imidazolium-5-olate and 2-azahypoxanthine, and examined pain reactions induced by these substances in mice. Mice were intraperitoneally administered each photodegradation product, then number of stretching reactions or writhing reactions as types of pain behaviors was counted. Only Diazo-IC clearly induced the pain reactions in mice in a concentration-dependent manner: the other products caused no pain reaction. The pain threshold of Diazo-IC in mice was estimated at between 0.1 mg/ml and 0.2 mg/ml. While diclofenac sodium significantly reduced acetic acid-induced pain reactions in mice, it did not influence the reactions induced by Diazo-IC. This result suggests that Diazo-IC-induced pain reactions represent a different mechanism from acetic acid-induced inflammatory pain. Degradation rate constant of 0.1 mg/ml of dacarbazine solution was 10 times larger than 1 mg/ml of dacarbazine. Dacarbazine solution for drip infusion should be sufficiently shielded from light