3-L split-dose is superior to 2-L polyethylene glycol in bowel cleansing in Chinese population: a multicenter randomized, controlled trial.

Large volume (4 L) of polyethylene glycol (PEG) solution would ensure a better quality of bowel cleansing but might be poorly tolerated. Due to the smaller body size, lower body weight, and different diet habits, the large volume of 4-L PEG might be poorly tolerated by the Chinese population. In view of this, a balance should be made between the volume and effectiveness. This study aimed to compare the effectiveness, compliance, and safety between 3-L split-dose and 2-L PEG in Chinese population. Consecutive patients scheduled for colonoscopy were recruited from 5 tertiary medical centers in South China between April and July, 2014. Patients were prospectively randomized into 2 groups: 3-L split-dose PEG (3L-group) and 2 L PEG (2L-group). The primary endpoint was bowel cleansing and was defined according to Ottawa Bowel Preparation Scale (OBPS). The safety and compliance were also evaluated. A total of 318 patients were included in the analysis. The mean total OBPS score was significantly higher in 2L-group than in 3L-group (4.4 ±â€Š2.7 vs 2.9 ±â€Š2.4, P < 0.001). Both the intention-to-treat and per-protocol analysis found that rates of successful and excellent bowel preparation were much higher in 3L-group (89.9% and 78.0%) than 2L-group (79.2% and 48.4%), respectively (P < 0.001). The average cecum intubation time was significantly shorter in 3L-group (8.2 ±â€Š3.7 min) than in 2L-group (10.3 ±â€Š4.2 min) (P = 0.04). Adenoma detection rate in right colon was slightly higher in 3L-group than in 2L-group (17.6% vs 12.6%, P = 0.21). The safety and compliance including the taste, smell, and dosage of PEG were similar between 2 groups (P > 0.05). 3-L split-dose PEG is superior to 2-L PEG by better bowel cleansing, improved safety and compliance, shorter cecum intubation time, and potentially higher adenoma detection rate in rightward colon in Chinese population.

Electrochemical characterization of self-assembled thiol-porphyrin monolayers on gold electrodes by SECM.

Herein, the scanning electrochemical microscopy (SECM) approach is applied to study the formation of thiol-porphyrin self-assembled monolayer (SAMs). Using cyclic voltammetry (CV), the formation process is characterized adopting different probe molecules. The observed phenomena indicate that the formation process is affected by solution properties and the molecular structure of the probe molecules. In K(3)Fe(CN)(6) , the SAMs show a strong electron-transfer (ET) blocking effect on a pure porphyrin-modified electrode. However, addition of metal ions to the porphyrin molecules leads to ET. A consistent tendency is observed throughout the modification process using CV and SECM methods. Furthermore, k(eff) values, the apparent heterogeneous rate constants, obtained for different modification periods affirm the validity of these results. SECM images are used to collect surface information in the course of the modification process when the substrate potential is 0.5 V versus Ag/AgCl. The effect of the substrate potential indicates that the oxidation of the porphyrin molecules is supported by more positive potentials because of the similar bimolecular reaction of the porphyrin ring with positive charge and the probe molecules with negative charge.