Efficient fabrication of tilt micro/nanopillars on polypropylene surface with robust superhydrophobicity for directional water droplet rebound.

The directional rebound and transport of water droplets plays an important role in microfluidic devices, anti-fogging, and water harvesting. Herein, an extrusion compression molding and directional stretch demolding method was used to prepare a polypropylene (PP) surface with tilt micro/nanopillars with a contact angle of 157 ± 3°. The rolling angle is the highest (9 ± 4°) when the direction of rotation is opposite the tilt direction of the micro/nanopillars, showing excellent water repellency and anisotropy of the surface. Compared with the position of the first collision of the water droplet, the position of the second collision shifted ∼1.5 mm along the tilt direction of the micro/nanopillars, driven by the surface tension component during the collision. The directional rebound behavior is controlled by the droplet energy and the tilt angle. The micro/nanopillars demonstrate excellent self-cleaning property and mechanical durability, which shows the possibility of their practical engineering applications.

[Effect of resveratrol on body composition in adult catch-up growth rats and its mechanism].

OBJECTIVE: To observe the effects of resveratrol on body composition in adult catch-up growth rats and to explore the possible mechanism. METHODS: Eight-week-old male SD rats were randomly divided into 6 groups: normal controls for 4 weeks (NC4) group, caloric restriction for 4 weeks (R4) group, calorie restriction meanwhile resveratrol treatment for 4 weeks (R4E) group, normal controls for 12 weeks (NC12) group, catch-up growth (CUG) group and catch-up growth meanwhile resveratrol treatment for 8 weeks (CUGE) group. At the end of the four-week and twelve-week experimental period, the body weight, muscle and fat content of trunk and whole body, the ratio of trunk to whole body fat were detected, and at the end of twelve-week experimental period, the expression of SIRT1 in skeletal muscle and epididymal adipose tissue, and the expression of PPARγ in epididymal adipose tissue were detected. RESULTS: Compared with NC12 group, the fat content of trunk and whole body and trunk to whole body fat ratio in CUG group were increased significantly, along with the expression of PPARγ in epididymal adipose tissue was increased significantly (P＜0.05), while the muscle content of trunk and whole body, the expression of SIRT1 in skeletal muscle and epididymal adipose tissue in CUG group were decreased significantly compared with NC12 group (P＜0.05 or P＜0.01); compared with CUG group, oral administration of resveratrol distinctly reduced the body fat content and trunk to whole body fat ratio in the CUGE groups, and the expression of PPARγ in epididymal adipose tissue of CUGE group was also significantly decreased (P＜0.05). Meanwhile, the muscle content and the expression of SIRT1 in skeletal muscle and epididymal adipose tissue in CUGE group were significantly increased compared with the CUG group (P＜0.05). CONCLUSION: Resveratrol can decrease body fat content, increase muscle content and improve abdominal fat accumulation in adult catch-up growth rats, and its mechanism may be associated with increasing SIRT1 expression in skeletal muscle and visceral adipose tissue, decreasing PPARγ expression in visceral adipose tissue.

The role of expression imbalance between adipose synthesis and storage mediated by PPAR-γ/FSP27 in the formation of insulin resistance in catch up growth.

BACKGROUND: Catch up growth (CUG) motivated by under-nutrition can lead to insulin resistance (IR) and visceral fat over-accumulation. However, the precise mechanisms on IR induced by adipose tissue changes during CUG remain unresolved. METHODS: Experimental rats were divided into three groups: normal chow group, catch up growth group and resveratrol administrated group. The whole experiment was carried out in four stages: 4, 6, 8 and 12 weeks. Peroxisome-proliferator activated receptor gamma (PPAR-γ) and fat-specific protein 27 (FSP27) expression level in epididymal adipose tissues (EAT) and subcutaneous adipose tissues (SAT) were detected along with other IR indicators. RESULTS: Calorie restriction (CR) significantly increased PPAR-γ expression in EAT while decreased FSP27 expression. During re-feeding, both of the expression of PPAR-γ and FSP27 increased, even FSP27 returned to normal level when CUG for 4 weeks. Although PPAR-γ expression declined slightly at 8 weeks, it was still much stronger than normal chow groups. However, no changes were seen in SAT. Relative insufficiency of FSP27 expression in EAT results in a decrease in lipid storage capacity, causing a series of path physiological changes that led to the formation of IR. Resveratrol inhibited the expression of PPAR-γ and promoted FSP27 expression, thus fundamentally improving IR. CONCLUSIONS: The imbalance between adipose synthesis and storage mediated by PPAR-γ / FSP27 in the EAT plays a pivotal role in the formation of IR during CUG. Resveratrol can correct fat formation and storage imbalance status by up-regulating FSP27 and down-regulating PPAR-γ expression level, ameliorating insulin sensitivity.