Novel quat/di-N-halamines silane unit with enhanced synergism polymerized on cellulose for development of superior biocidability.

A silane unit with enhanced synergism that is realized using one cationic quaternary ammonium salt (QAS) to draw anionic bacteria to two N-halamine functionalities was designed and polymerized on cellulose for superior biocidability. A monomer containing one tertiary amine, one amide N-H, and one imide N-H, was synthesized via alcoholysis of 3-triethoxysilylpropyl succinic anhydride with 2-(dimethylamino)ethan-1-ol and following esterification with 5-(4-hydroxyphenyl)hydantoin. The triethoxysilyl groups of the monomer were hydrolyzed to silanol groups to condense with counterparts in different hydrolyzates and with hydroxyl groups on cellulose to form a polymeric modifier. Each silane unit of the modifier has one QAS and two N-halamine functionalities (quat/di-N-halamines) after quaternization of the tertiary amine and chlorination of the amide and imide hydrogens. The resultant cellulose suppressed (7 logs) both Staphylococcus aureus and Escherichia coli within 3 min, demonstrating an enhanced synergism since the inactivation rate is faster than counterparts decorated with only N-halamine and with synergistic units of one cationic center and one N-halamine. The modifier exhibited promising stability and rechargeability toward washings, UV irradiation, and long-term storage. The proved enhanced synergism from the integration of one cationic center with multiple N-halamines directs the synthesis of more powerful biocides for developing antibacterial polymers.

Doppler Characteristics of Cavernosal-Spongiosal Communications in Patients with Erectile Dysfunction.

The goal of this work was to characterize the blood flow in cavernosal-spongiosal communications (CSCs) in patients with erectile dysfunction using color Doppler ultrasound. Peak systolic velocity was measured in the CSCs, cavernosal artery and urethral artery in 72 erectile dysfunction patients of the Han ethnic group in southern China. Blood in the CSCs was observed to flow from the cavernosal artery to the urethral artery in all except 5 patients with arteriogenic insufficiency whose blood flow was bidirectional. Peak systolic velocity in erectile dysfunction patients with normal vascular function or veno-occlusive dysfunction was significantly lower in the CSCs than in the cavernosal artery (p < 0.01), but significantly higher than in the urethral artery (p < 0.05). Peak systolic velocities in CSCs in patients with arteriogenic insufficiency were significantly lower than those in the cavernosal (p < 0.01) and urethral (p < 0.01) arteries. The direction of blood flow in the CSCs is determined by the pressure gradient between the cavernosal and urethral arteries.