[Brain Fog: A Concept Analysis].

Brain fog is a symptom that has gained increasing attention worldwide since the start of the COVID-19 pandemic, as patients affected by COVID-19 may experience cognitive dysfunction, colloquially known as brain fog, for a period of time after recovery. Brain fog affects activities of daily living and work performance and has the potential to negatively impact society and the economy. However, a clear definition and concept analysis of brain fog is lacking in the literature. In this article, a concept analysis of brain fog is conducted using Walker and Avant's concept analysis steps to verify the source and definition of brain fog, clarify related concepts similar to brain fog, and establish the defining attributes, antecedents, and consequences of this condition. Model, borderline, contrary, and related cases are listed to illustrate and provide related empirical references in the literature. The authors hope this article will provide a clearer understanding of brain fog, which then may be applied in nursing clinical practice and future research to develop strategies and care methods for improving brain fog symptoms.

Fluorimetric liquid chromatographic analysis of amantadine in urine and pharmaceutical formulation.

A simple and sensitive liquid chromatographic method is described for the analysis of amantadine and memantine. The method is based on the derivatization of amantadine and memantine extracted from alkalified samples with (2-naphthoxy)acetyl chloride at mild conditions. The resulting derivatives were analyzed by isocratic HPLC with a fluorimetric detector (lambdaex, 227 nm; lambdaem, 348 nm). The linear range for the determination of amantadine or memantine spiked in urine (1.0 ml) was 1.0-10.0 nmol with a detection limit of about 0.2 nmol (S/N = 3; injected sample 20 microl). Only amantadine preparations are available on our local market, and application of the method to the analysis of amantadine in formulation and in the urine of a dosed subject was demonstrated and proved feasible. Quantitation of AT in tablets or capsules is capable in the linear range of 2.0-50.0 microM. Toluene was used as the solvent for extracting amantadine or memantine in samples and the resulting toluene extract was directly subjected to subsequent derivatization without solvent replacement leading to a simpler analytical procedure.