ABSTRACT
Nearly athermal colloid-polymer mixtures were studied in the "protein limit." A fluid-fluid transition was observed in mixtures of stearyl-alcohol-coated silica particles and large polystyrene coils in toluene. The ratios of the polymer radius of gyration to the particle radii were q=4.1 and q=5.2. The binodal curves and the critical points were determined. Turbidity measurements and analysis for one set of particles allowed the systems to be mapped onto hard sphere-polymer mixtures. A comparison with recent predictions for the miscibility of model mixtures shows that the experimental binodals lie between the two extreme results for ideal and interacting polymers. The critical colloid volume fraction is also found to decrease with increasing size ratios.
ABSTRACT
A retrospective study of a group of 51 patients who underwent surgery for squamous cell carcinoma of the pyriform sinus was performed. Primary tumors and lymph nodes were reviewed histologically. The primary tumors were also examined by flow cytometry for DNA ploidy and cell cycle analysis. Sixteen (33%) of the cases were aneuploid and 64% had a moderate or high S-phase fraction. The overall 3-year survival rate was 49% (25/51). In the univariate analysis, tumor size, lymphatic invasion, inflammatory infiltrate, presence of lymph node metastases, clinical and histologic N status, size and number of lymph nodes involved, and presence of extracapsular extension all correlated with survival. When multivariate analysis was used, the only independent prognostic factors were tumor size, lymphatic invasion, and histologic N status. Ploidy and S-phase fraction did not contribute further prognostic information.