Controlled Integration of Interconnected Pores under Polymeric Surfaces for Low Adhesion and Antiscaling Performance.

Low-adhesive surfaces have been highlighted due to the potentials to mitigate fouling issues by preventing unwanted substances from adhering. Realizing superhydrophobicity with 3D surface structures/chemical modifiers or fabricating lubricant-assisted slippery surfaces has been demonstrated to realize low-adhesive surfaces. However, they still need to overcome the transition to Wenzel from Cassie states of droplets on 3D surface structures or the lubricant depletion issues of slippery surfaces for sustainable operations. Herein, we report the fabrication of low-adhesive polymeric surfaces, neither assisted by 3D surface structures/chemical modifiers nor lubricants, which is realized by embedding the interconnected pore networks underneath the top smooth surface using a water steaming method. The fabricated silicone surfaces exhibit low-adhesive properties due to the stress concentration effects generated by the subsurface-structured pores, favorable for easy detachment of the adherent from the surface. Our platform can be exploited to lower adhesion of superhydrophilic surfaces or to achieve ultralow-adhesive properties upon combination with superhydrophobicity. Finally, scale precipitation tests reveal 4.2 times lower scale accumulation of our low-adhesive polymeric surfaces than that in control samples.

Water-repellent Hybrid Nanowire and Micro-scale Denticle Structures on Flexible Substrates of Effective Air Retention.

The air retention capability of a superhydrophobic surface plays the crucial role of drag reduction in an aqueous environment. Here, fabrication of water-repellent hybrid structural surfaces by synthesizing superhydrophobic nanowires with a high aspect ratio on micro-scale denticle structures to improve their air holding capacity in water is reported. The hybrid structure is realized by carrying out polymer molding of denticle structures on flexible substrates, hydrothermal growth of nanowires, and subsequent ultra-thin film coating. This technique is readily applicable to large areas, and the fabricated substrates are attachable onto curved surfaces. Our engineered, super water-repellent hybrid structures are found to effectively maintain air bubbles on their surfaces in a highly shear flow condition with a wall shear stress of up to 33.4 Pa, due to the combined effects of the micro-scale denticle structure, which reduces flow resistance, and the superhydrophobic, high-aspect-ratio nanowire structure, which enhances the capillary force to maintain the air bubbles. Our results show the importance of developing superhydrophobic structures of improved air retention capability.

Six weeks of combined aerobic and resistance exercise using outdoor exercise machines improves fitness, insulin resistance, and chemerin in the Korean elderly: A pilot randomized controlled trial.

BACKGROUND: The aim of this study was to investigate the effect of a six-week-long exercise program using outdoor exercise equipment on fitness, insulin resistance and adipocytokines among Korean elderly. METHODS: A total of 47 participants were randomized into one of the following three groups; control, resistance exercise or combined exercise (aerobic and resistance exercise). The resistance exercise group completed three resistance types of exercise. The combined exercise group completed five exercises, including three resistance types of exercise and two aerobic types of exercise. Participants' body composition, fitness level, homeostasis model assessment of insulin resistance (HOMA-IR), and adipocytokines were measured at baseline and at the end of six weeks. RESULTS: After six weeks of exercise training, participants in the combined exercise group exhibited significant reduction in insulin, HOMA-IR and chemerin levels, while significant reduction was observed in HOMA-IR only in the resistance exercise group compared with the control group. Meanwhile, six weeks of exercise training, whether resistance exercise alone or combined, significantly improved upper body muscular strength/endurance and physical function compared to the control group. CONCLUSIONS: Six weeks of combined exercise using outdoor exercise equipment was effective in improving fitness, HOMA-IR, circulating chemerin levels, and other known risk factors of chronic diseases.

Ultrasonic, chemical stability and preparation of self-assembled fullerene[C60]-gold nanoparticle films.

C(60)-functionalized gold nanoparticle films were self-assembled on the reactive surface of glass slides functionalized with 3-aminopropyltrimethoxysilane. The functionalized glass slides were alternately soaked in the solutions containing unmodified C(60) and 4-aminothiophenoxide/hexane thiolate-protected gold nanoparticles. Organic reaction (amination) facilitated the layer-by-layer multilayer film assembly. C(60)-functionalized gold nanoparticle films have grown up to several layers (upto 5 layers were examined) depending on the immersion time. The assembled nanoparticle films were characterized using UV-vis spectroscopy. The chemical stability of C(60)-gold nanoparticle films was studied by monitoring the changes in absorbance after the immersion of the films in acidic solutions. The ultrasonic stability of these nanoparticle films was studied by exposing them to ultrasonic irradiated surrounding, which results in the aggregation of nanoparticles on solid surfaces.