ABSTRACT
Oral chemotherapy is increasingly used in oncology. Poor adherence, that is, non-respect of medical advice about taking the therapy and surveillance of adverse effects, is the main risk associated with this administration route. Poor adherence may be explained by non-adherence by the patient to the treatment, misunderstanding the advice or it could also reflect the poor adaptation of the healthcare team to a new administration route. Here we report the results from a qualitative study that aimed to describe and understand existing practice for capecitabine, an oral chemotherapy, which is used for the treatment of metastatic breast and colon cancer. We interviewed 42 patients who were receiving oral capecitabine in groups and individually as well as 10 prescribers. This study was carried out in two specialist cancer centres. The results showed a wide diversity in the prescribers' practices, who make decisions based on their experience of practice guidelines for intravenous chemotherapies. Although the results for the patients do not suggest deliberate non-adherence, they show poor observance of the dose schedule. The most important result of this study is the patient's inability to identify and to report important signs of harmful toxicity.
Subject(s)
Antineoplastic Agents/administration & dosage , Breast Neoplasms/drug therapy , Colonic Neoplasms/drug therapy , Deoxycytidine/analogs & derivatives , Fluorouracil/analogs & derivatives , Medication Adherence , Administration, Oral , Aged , Aged, 80 and over , Capecitabine , Deoxycytidine/administration & dosage , Drug Administration Schedule , Female , Fluorouracil/administration & dosage , Humans , Male , Middle Aged , Practice Patterns, Physicians' , Qualitative Research , Risk FactorsABSTRACT
A high-sensitivity polarimeter is demonstrated for application to gas-phase chirality measurement. This device is based on the physics of the eigenstates of a Fabry-Perot cavity, permitting improvement in the sensitivity with respect to the usual polarimeters. Typical measurements of rotations of 50 (±1) × 10(-)(5)° induced by the optical activity of (R)-(+)-limonene and (S)-(-)-limonene in the vapor phase are shown. A noise level corresponding to a rotation of 10(-)(6)° is experimentally demonstrated. Application to the polarimetric monitoring of an enantiomer mixing racemization of limonene in the gas phase is also presented.
ABSTRACT
The reflection coefficient of the Faraday isolator-mirror system in the presence of internal reflections of the incident Gaussian beam is theoretically and experimentally explored for three different architectures of a Faraday isolator. In every case, these internal reflections are shown to alter widely the behavior of the system. In particular, we propose and test a design using a quarter-wave plate that can, in some experiments, give better isolation ratios than conventional isolators.
ABSTRACT
The Jones matrix of a quarter-wave plate is studied theoretically and experimentally, taking into account internal reflections, the ellipsoid of the indices, geometric defects, the tilt angle, and the characteristics of the incident Gaussian beam. The influence of the different parameters is isolated, and large discrepancies are observed with respect to results obtained from the Jones matrix that are usually given in textbooks. It is shown that the effective Jones matrix of the plate does not depend on the longitudinal position of the plate on the Gaussian beam but only on the beam-waist size. This leads to a method of characterization of the defects of a quarter-wave plate that is more precise than the usual methods. Different procedures to optimize the efficiency of a given plate are discussed, taking the plate defects into account. In all cases, a good agreement between experiments and theory is obtained.