Adsorption of cationic surfactants (dodecyltrimethylammonium bromide, 1RQ; 1,2-bis(dodecyldimethylammonio)ethane dibromide, 2RenQ) has been investigated on titanium dioxide with a dodecyl chain anchor. The adsorbed amounts of 1RQ and 2RenQ increase with increasing concentration of the dodecyl chain anchor on titanium dioxide, where the adsorbed amounts of 1RQ at saturation are considerably greater than those of 2RenQ. Changes in the dispersion stabilities and the ζ potentials of the titanium dioxide suspensions are well correlated with the adsorption behaviors of the surfactants. The adsolubilized amounts of 2-naphthol in the surfactant-adsorbed layer also increase with increasing concentration of the dodecyl chain anchor for 1RQ and 2RenQ, whereas those with 2RenQ are greater than those with 1RQ even though there is a smaller amount of adsorbed 2RenQ. These differences in the adsolubilization are attribued to the surfactant compactness in the adsorbed layer estimated by ESR.

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Background: As the second-line chemotherapy for stage IV recurrent or nonresectable colorectal cancer, our hospital started a modified treatment regimen comprising of irinotecan plus S-1 (IRIS) [tegafur/ gimeracil/oteracil (S-1)] plus molecular targeting agents (MTAs), i.e., an epidermal growth factor receptor (EGFR) inhibitor such as panitumumab (P-mab) or cetuximab (C-mab) or vascular endothelial growth factor (VEGF) inhibitor such as bevacizumab (B-mab) since October 2012. The purpose of this study is to evaluate the efficacy and safety of this modified regimen.Methods: This retrospective study included 41 patients with advanced recurrent colorectal cancer at our hospital whom at least 3 courses of chemotherapy were conducted from January 2015 to December 2021.Based on the location of the primary tumor, patients were classified into two group (right-sided group, proximal to the splenic curve, and left-sided, distal to the splenic curve). We assessed archived data on RAS and BRAF status and UGT1A1 polymorphisms and use of the VEGF inhibitor bevacizumab (B-mab) and the EGFR inhibitors panitumumab (P-mab) and cetuximab (C-mab). In addition, progression-free survival rate (36M-PFS) and the overall survival rate (36M-OS) were calculated. Furthermore, the respective median survival time (MST), the median number of treatment courses; the objective response rate (ORR) and clinical benefit rate (CBR) and the incidence of adverse events (AEs) were assessed as well.Results: There were 11 patients (26.8%) in the right-sided group, and 30 patients (73.2%) in the left-sided group. There were 19 patients with RAS wild type (46.3%) (1 in the right sided group and 18 in the left sided group). P-mab was used for 16 of these patients (84.2%), C-mab for 2 (10.5%), and B-mab for 1 (5.3%); the remaining 22 patients (53.7%). Ten (10 patients) in the right group and 12 patients in the left group were a mutated type and received B-mab. BRAF testing was performed in 17 patients (41.5%); as more than 50% of patients (58.5%) were included before the assay's introduction. 5 patients in the right-sided group and 12 patients in the left-sided group had wild type. There was no mutated type. UGT1A1 polymorphism was tested in 16/41 patients: Eight were wild type (8/41 patients, 19.5%) and 8, mutated type. Regarding the *6/*28 double heterozygous type, there was only 1 patient in the right-sided group and the remaining 7 patients were in the left-sided group. The total number of chemotherapy courses was 299, and the median number, 6.0 (range, 3-20). PFS, OS, and MST were as follows: 36M-PFS (total/Rt/Lt), 6.2%/0.0%/8.5%