RESUMEN
The effect of a magnetic field on the steady-state and time-resolved optical emission of a custom fullerene-linked photosensitizer (PS) in liposome cell phantoms was studied at various oxygen concentrations (0.19-190 microM). Zeeman splitting of the triplet state and hyperfine coupling, which control intersystem crossing between singlet and triplet states, are altered in the presence of low magnetic fields (B < 320 mT), perturbing the luminescence intensity and lifetime as compared to the triplet state at B = 0. Measurements of the luminescence intensity and lifetime were performed using a time-domain apparatus integrated with a magnet. We propose that by probing magnet-affected optical emissions, one can monitor the state of oxygenation throughout the course of photodynamic therapy. Since the magnetic field effect (MFE) operates primarily by affecting the radical ion pairs related to type I photodynamic action, the enhancement or suppression of the MFE can be used as a measure of the dynamic equilibrium between the type I and II photodynamic pathways. The unique photo-initiated charge-transfer properties of the PS used in this study allow it to serve as both cytotoxic agent and oxygen probe that can provide in situ dosimetric information at close to real time.
Asunto(s)
Sustancias Luminiscentes/química , Magnetismo , Oxígeno/análisis , Fotoquimioterapia , Fármacos Fotosensibilizantes/química , Fulerenos/química , Sustancias Luminiscentes/síntesis química , Fantasmas de Imagen , Fármacos Fotosensibilizantes/síntesis química , Factores de TiempoRESUMEN
We show that the generalized nonlinear Schrödinger equation admits of an analytical solution for a bright optical soliton in the presence of fourth-order dispersion. The soliton envelope is expressed as the square of a hyperbolic secant. The peak power and the duration of the soliton are uniquely defined. Numerical simulations tend to show that the temporal shape and the peak power of the soliton are stable when a weak third-order dispersion is introduced.
RESUMEN
We show that thermal aberration in optically pumped solid-state lasers can lead to the breakup of the beam profile. Kerr lensing present in the self-mode-locked regime tends to reduce the beam size in the laser material; such a beam is less sensitive to the thermal aberration, and its shape becomes free of secondary lobes. The thermal aberration has also the effect of moving the optimal operation point for self-mode locking. Experimental results obtained with a Ti:sapphire laser support our theoretical results.
Asunto(s)
Terapia Conductista/métodos , Ingestión de Líquidos , Trastornos Psicóticos/rehabilitación , Esquizofrenia/rehabilitación , Psicología del Esquizofrénico , Intoxicación por Agua/prevención & control , Adulto , Enfermedad Crónica , Internamiento Obligatorio del Enfermo Mental , Humanos , Masculino , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Factores de Riesgo , Esquizofrenia/diagnóstico , Régimen de Recompensa , Intoxicación por Agua/psicología , Aumento de PesoRESUMEN
The synthesis of two silyl-linked hexanucleotide analogues is described. Hypochromicity and CD measurements indicate that the thymidine hexanucleotide analogue bears a strong resemblance to its phosphodiester-linked counterpart.
Asunto(s)
Oligonucleótidos/síntesis química , Silanos , Silicio , Dicroismo Circular , Indicadores y Reactivos , Conformación de Ácido Nucleico , Relación Estructura-Actividad , TimidinaRESUMEN
A program for routine pharmacokinetic interpretation of serum analyses of gentamicin, tobramycin, amikacin, phenytoin, phenobarbital, theophylline, lidocaine, digoxin, quinidine, and procainamide at the Medical University of South Carolina Hospital is described. Results of all analyses of serum for the drugs listed are evaluated by a pharmacist trained in clinical pharmacokinetics. Patient variables relevant to the determination of drug serum concentrations, drug elimination, distribution, and dosage are given appropriate consideration in each evaluation. A summary of the pharmacokinetic interpretation and any necessary modification of drug dosage regimens are then written into the progress notes of the patients' medical records. Approximately 12 patients and 20 drug concentrations are evaluated each day. The average charge for te service is +35. This service, which is reimbursed by third-party carriers, has resulted in improved use of laboratory personnel, equipment, and time and has provided a framework for education and research as well as a mechanism for direct contributions to patient care by the pharmacist.