A model theory of passive-targeted drug delivery in sphere-shaped solid tumors is introduced on the basis of Fick's law of diffusion, with appropriate boundary and initial conditions. For a uniform initial concentration inside the tumor, the concentration is obtained as a function of time and radial position. The concentration is shown to approach the equilibrium distribution as the time elapses, as is expected by the Gedanken Experiment. The time-evolution rate is found to be determined by the diffusion coefficient of the drug in the tissue, the size of the tumor, the volume of the drug-injected region, and the concentration gradient at the boundary.
Diffusion ; Jurisprudence

BACKGROUND AND OBJECTIVES: Although tonsillectomy is one of the most often performed surgeries in Otorhinolaryngology, there has not been any long-term postoperative follow-up studies until now. The authors aimed to validate once more, in a long-term follow up study, the need for performing tonsillectomy. MATERIALS AND METHODS: Medical records of 180 adult patients who have received tonsillectomy were retrospectively studied, and telephone surveys were made to the patients. The telephone questionnaire was designed to find out the postoperative pain, complications such as bleeding, the time each patient took to return to the normal diet and social life, the degree of improvement in the symptoms and the satisfactory rate. RESULTS: The chief complaints were recurrent sore throat. There was no immediate postoperative bleeding, but secondary bleeding occurred in 12.8% of the patients. The postoperative pain scored 7.4 in a scale of one to ten. The average time in returning to the normal diet and the normal life was 17.9, 21.1 days, respectively. Studies in the symptomatic improvement showed almost no or minimal residual symptom in 99% of the patients and about 95% of the patients answered positively in satisfactory category. CONCLUSION: Tonsillectomy caused great pain postoperatively in most of the patients and returning to the normal diet and life took fairly a long time. However, the positive answers about the symptomatic improvement and the high satisfaction rate validates tonsillectomy as an effective surgical treatment for patients with recurrent tonsillitis.
Adult* ; Diet ; Follow-Up Studies ; Hemorrhage ; Humans ; Medical Records ; Otolaryngology ; Pain, Postoperative ; Palatine Tonsil ; Pharyngitis ; Surveys and Questionnaires ; Retrospective Studies ; Telephone ; Tonsillectomy* ; Tonsillitis