Biosurface and Biotribology最新文献

The anti-friction function of superwetting surfaces with superhydrophobicity has been demonstrated. However, the influence regularity of wettability to tribological performance, and the underlying mechanism are still unclear. Here, two kinds of microstructured surfaces with different wettability are fabricated on the substrate of steel by controlling surface chemical compositions. The water contact angles on these surfaces range from 0° to 151°. The ball-plate tribological tests are performed under water lubrication. The results show that the tribological performance is closely related to surface wettability. The friction coefficient increases with the increase of contact angles when the surfaces are hydrophilic rather than superhydrophilic. In contrast, the friction coefficient on the hydrophobic surfaces decreases with the increase of contact angles. Furthermore, the best anti-friction capability is obtained on the superhydrophobic surfaces, and the anti-friction mechanism is elucidated. The lowest friction coefficient was 0.12 under the load of 10 N. This work provides strong evidence of an association between tribological property and wettability, which may inspire the fabrication and application of special wetting surfaces in friction control.

In recent years, the need for the capability of decelerating the ripening process has increased significantly, especially in countries such as India where the post-harvest loss is ∼630 billion dollars annually. The ripening process primarily starts with transpiration and respiration through microscopic pores present on the fruit. Accordingly, edible coatings can act as barriers, reducing the acceleration of these biochemical processes and enhance the shelf-life of the fruit. For this study, 2% chitosan enriched with peel extracts from Citrus limon and leaf extracts from Ocimum tenuiflorum were used as an edible coating and the quality of bananas was evaluated over time. The ripening process was found to be delayed for a significant amount of time. The study also revealed increased anti-oxidant activity based on absorbance changes of 2,2-diphenyl-1-picrylhydrazyl, which correlated with the phytochemical content of the fruit.

Volleyball activities involve several factors such as asymmetrical movements, muscle imbalance, and continual overloading that damage body posture. This study aimed to determine postural changes of volleyball players in spike overhand front set, overhand pass ball, and mat ball motions, and if there is any postural variation difference between short training and long training volleyball players. Methods: Fifteen long training and short training male volleyball players aged 21–23 years were recruited in this study. The upper-thoracic angle, thoracic-lumbar segment angle, lower lumbar-sacral segment, pelvic inclination, and inclination of the acromion were measured using DIERS formetric 3D device in a dynamic way. During the overhand pass motion, long training participants showed a significant larger peak upper-thoracic and peak thoracic-lumbar angles than short training participants. During the mat ball motion, the long training volleyball players demonstrated a significant higher peak upper-thoracic angle, but a smaller peak inclination of the acromion than short trainers. During the spike overhand front set motion, long trainers showed a significant smaller peak upper-thoracic angle than short trainers. Athletes should consider developing an appropriate dynamic trunk stabilization to reduce posture imbalance during volleyball activities.

The lubricity and anti-wear ability of ionic liquids (ILs) were studied by a current-carrying friction test on IL-lubricated carbon brushes. The results indicated that the conductivity and wear resistance of different ILs are different, and may vary for different carbon brushes. The E468e carbon brush was found to be more sensitive to IL lubrication than D172 carbon brush. Importantly, an analysis of the wear surfaces of the D172 and E468e carbon brushes revealed that, due to the different materials of the two carbon brushes and the composition of the IL, the lubrication effect on the carbon brushes was different. The viscosity of the IL will affect its wettability on the carbon brush surface. The better the wettability, the easier the movement of ions on the surface, which makes it easier to form a conductive physical adsorption film. Therefore, in practice, a better IL must be selected by considering the wettability of IL and carbon brushes.

Hybrid interfaces between living cells and organic conjugated polymers play a pivotal role in bioelectronics medicine. Currently, conjugated polymers are widely utilised for optical stimulation of living cells and other bio-interface applications such as neural probes, cellular scaffolds and biosensors for drug release. In such a work, the authors fabricated and characterised the Nano Photodiode array device for the subretinal implant. However, the authors did not discuss in their report about the biocompatibility of this new device. In this work, the authors manifest that the quintessential graphene electrode and polymer blend of semiconducting single-wall carbon nanotube and C₆₀ fullerene (S-SWCNT:C₆₀) sustains its optoelectronic properties all through the various strides for neural preparation. Further, the studies show that these materials can provide a favourable environment for cell proliferation and a high degree of biocompatibility. PC-12 cells used as a valuable model to validate the biocompatibility were grown successfully onto the S-SWCNT:C₆₀ active layer still preserving its optical and electrical properties. The improved electrical performance of nano photodiode made of graphene, S-SWCNT:C₆₀ established in the previous studies and the excellent bio-interface performance of this nano photodiode shows that the nano photodiode array proposed by the authors is a strong candidate for subretinal implants.

Exogenous grit adherent to the surface of food items and food fracture properties have each been considered important factors contributing to pattern and degree of tooth wear in mammals. However, the interactions between these two factors in generating distinctive microwear textures have remained understudied. Here the authors revisit in-vitro results from simulated chewing to explore how adherent grit and physical properties of foods act together to create dental microwear textures on occlusal enamel surfaces. Results suggest that the effect of exogenous grit on microwear texture is dependent on the material properties foods to which they adhere. Grit in the absence of food causes more complex microwear surface textures than foods covered with similar levels and types of grit (for a given number of chews and angle of approach between opposing teeth). Different foods covered in grit also yield different complexity values. Grit-laden, pliant meat, for example, results in a less complex texture than does resistant, grit-laden raw carrot. This work implied that tooth wear assessment can benefit from considering grit load and food material properties together.