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The Morpho butterfly is famous for its typical structural color and has increasingly attracted the interest of scholars in a wide variety of research fields. Herein, it was found that the color of Morpho menelaus butterfly wings is not only structure-based but also viewing-angle-dependent. Firstly, the discoloration effect of this typical butterfly was confirmed by a series of experiments. Then, the general form, arrangements, and geometrical dimensions of the scales were observed using a stereomicroscope. Scanning electron microscopy was also used to examine the two-dimensional morphologies and structures of a single scale. Afterwards, one model with the optimized three-dimensional profile of the structure was described using Pro-engineer software. The associate model was then analyzed to reconstruct the process between the incident light and the model surface. Finally, the mechanism of the angle-dependent discoloration effect was analyzed by theoretical calculation and optical simulation. Different light propagation paths and the length of the incident light at different angles caused destructive or constructive interference between the light reflected from the different layers. The different spectra of the reflected light make the wings appear with different structural colors, thereby endowing the angle-dependent discoloration effect. The consistency of the calculation and simulation results confirms that these structures possess an excellent angle-dependent discoloration effect. This functional “biomimetic structure” would not only be of great scientific interest but could also have a great impact in a wide range of applications such as reflective displays, credit card security, and military stealth technology.

The morphology and wettability of Water Bamboo Leaves (WBL) and their biomimetic replicas were investigated. The particular morphology structures of samples were characterized by Scanning Electron Microscopy (SEM) and Confocal Laser Scanning Microscopy (CLSM). The static wettability of samples was assessed by contact angle measurements, while the dynamic wettability was analyzed by high speed camera system. The wettability mechanism of WBL was also explained by Cassie model. Artificial surfaces were fabricated by duplicating WBL surface microstructures using PDMS in large area (5 cm × 3 cm). The results show the main structure characteristics of this leaf surface are sub-millimeter groove arrays, micron-scale papillae and a superimposed layer with 3D epicuticular wax sculptures hierarchical structure, and the static Water Contact Angle (WCA) of 151°±2° and Water Sliding Angle (WSA) of 4°–6° indicate that WBL surface is superhydrophobic. The combination of wax film and microstructure of WBL surface gives its surface excellent superhydrophobic property. Complex hierarchical patterns with features from sub-millimeter to micron-scale range are well reproduced. The reason for the absence of nanostructures is melting of plant epidermal wax during the curing process. The WCA values on artificial WBL and negative PDMS replica are 146° ± 3° and 137° ± 2°, respectively, demonstrating preferable hydrophobicity. Differences in wetting behavior between natural leaves and artificial leaves originate from an inaccurate replication of the chemistry and structures of the three-dimensional wax projections on the leaf surface. Nevertheless, the morphological features of the leaf transferred to the replica improve significantly the hydrophobic properties of the replica when compared with the smooth PDMS reference. This study may provide an inspiration for the biomimetic design and construction of large area roughness-induced hydrophobic and anti-sticking material surface.

ObjectiveTo investigate the effect of sorafenib and/or thalidomide on angiogenesis in chick chorioallantoic membrane (CAM). MethodsWhite eggs incubated for 7 days were used to establish a CAM model. The model eggs were randomly divided blank control group, sorafenib group, thalidomide group, and sorafenib/thalidomide group. After treatment, each egg was incubated for another 2 days. The CAM samples were collected and fixed to take their pictures under a microscope, and the vascular coverage of each sample was calculated. Comparison between these groups was made by analysis of variance, and comparison between each two groups was made by SNK-q test. ResultsThe thalidomide group or sorafenib group had significantly lower vascular coverage than the blank control group (30.2%±2.9% or 26.5%±2.1% vs 38.3%±2.7%, P＜0.05). The sorafenib/thalidomide group had significantly lower vascular coverage than the thalidomide group or sorafenib group (12.6%±1.5% vs 30.2%±2.9% or 26.5%±2.1%, P＜0.05). ConclusionBoth sorafenib and thalidomide have a good anti-angiogenic effect on CAM, but a combination of the two drugs shows better efficacy.

Butterflies are famous for their brilliant iridescent colors, which arise from the unparalleled photonic nanostructures of the scales on their wings. In this paper, the sensitivity characteristics of the photonic structures in butterfly wings to surrounding media were found. First, it was shown that the iridescent scales of Morpho menelaus butterfly give a different optical response to surrounding vapours of water, ether and ethanol. Then, the ultra-depth three-dimensional microscope and FESEM were used to observe the morphology and nanostructures of butterfly wing scales. The high spectral response characteristics were identified by using an Ocean Optics spectrometer USB4000. It was found that the reflectance spectra of the Morpho menelaus butterfly scales could provide information about the nature of the surrounding vapours. Afterwards, the theory of multilayer-thin-film interference was used to analyse the mechanism of this sensitivity. It was determined that the multilayer-thin-film interference structure constituted by alternating films with high and low refractive indexes, leading to the sensitivity of butterfly wings. The refractive indexes of surrounding media play an important role in gas sensitivity. These characteristics dramatically outperform those of existing nano-engineered photonic sensors and may have potential in the design of efficient and high sensitivity optical gas sensors.