Sodium hydroxide solution

After macroscopic examination, the bony characteristics of the aponeurotic attachment of the external oblique–adductor longus and that of the rectus abdominis–pyramidalis–gracilis–adductor brevis on the pubis were analyzed in two specimens using micro-CT (inspeXio SMX-100CT; Shimadzu Corp., Kyoto, Japan) with 200-μm resolution and ImageJ (version 1.52; National Institutes of Health, Bethesda, MD, USA). After collecting the three-dimensional (3D) images, to ensure that the 3D-CT image configuration accurately represented the bony surface without dissection artifacts, the soft tissues were chemically removed from the same specimens using a 1% sodium hydroxide solution (Wako Pure Chemical Industries, Osaka, Japan).

κ-Carrageenan (κ-CRG), potassium chloride, methylene blue trihydrate (Mb), pentasodium triphosphate (TPP), acetic acid, hydrochloric acid, sodium hydroxide solution, and toluene were purchased from Wako Pure Chemical Industries (Osaka, Japan). ι-Carrageenan (ι-CRG) and poly-l-lysine (405 kDa, PLL) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Sodium 2-naphthalenesulfonate (Ns) was purchased from Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). Chitosan (100 kDa, CS) was obtained from Dainichiseika Color & Chemicals Mfg. Co., Ltd. (Tokyo, Japan). Poly(ethylene glycol)-b-poly(ε-caprolactone) block copolymer (PEG-b-PCL) was synthesized as a polymeric surfactant according to a previously reported method [28 (link),29 (link)] with slight modifications (M_ns of the PEG and PCL units were 3500 and 4300, respectively; M_w/M_n ratios of PEG and PEG-b-PCL were 1.09 and 1.35, respectively). All other reagents were of analytical grade and used without further purification. The chemical structures of κ-CRG, ι-CRG, CS, PLL, TPP, Mb, and Ns are shown in Figure S1.

First, to confirm the effect of temperature, 0.05 g of adsorbents samples, namely Lig and Lig800, were mixed with a Cd(II) solution of 50 mL at 5, 10, 20, 30, 40, 50, 80, 100, and 300 mg/L. The reaction mixtures were shaken at 100 rpm for 24 h at 25 and 50 °C. Second, to confirm the effect of contact time, the same adsorbent samples (0.05 g) were mixed with a Cd(II) solution of 50 mL at 100 mg/L. The reaction mixtures were then shaken at 100 rpm for 1 and 10 min as well as for 0.5, 1, 2, 6, 22, and 24 h at 25 °C. Finally, to confirm the effect of pH, the same adsorbent samples (0.05 g) were mixed with a Cd(II) solution of 50 mL at 100 mg/L. The solution pH was adjusted from 3 to 6 by adding either hydrochloric acid or sodium hydroxide solution (FUJIFILM Wako Pure Chemical Co., Osaka, Japan). The reaction mixtures were shaken at 100 rpm for 24 h at 25 °C. The adsorption capacity on Cd(II) was calculated using the levels before and after each experiment. The student's t-test was used for a comparative analysis of two groups. A minimum p-value of 0.05 (p < 0.05) was chosen as the significance level.