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Neural style transfer, as a new auxiliary means for digital art design, can reduce the threshold of technical design and improve the efficiency of creation. The existing methods have achieved good results in terms of speed and style quantity, but most of them change or erase the semantic information of the original content image to varying degrees during the process of stylization, resulting in the loss of most of the original content features and emotion; although some methods can maintain specific original semantic mentioned above, they need to introduce a corresponding semantic description network, leading to a relatively complex stylization framework. In this paper, we propose a multi-semantic preserving fast style transfer approach based on Y channel information. By constructing a multi-semantic loss consisting of a feature loss and a structure loss derived from a pre-trained VGG network with the input of Y channel image and content image, the training of stylization model is constrained to realize the multi-semantic preservation. The experiments indicate that our stylization model is relatively light and simple, and the generated artworks can effectively maintain the original multi-semantic information including salience, depth and edge semantics, emphasize the original content features and emotional expression and show better visual effects. [ABSTRACT FROM AUTHOR]

Neural style transfer has effectively assisted artistic design in recent years, but it has also accelerated the tampering, synthesis, and dissemination of a large number of digital image resources without permission, resulting in a large number of copyright disputes. Image steganography can hide secret information in cover images to realize copyright protection, but the existing methods have poor robustness, which is hard to extract the original secret information from stylized steganographic (stego) images. To solve the above problem, we propose an improved image steganography framework for neural style transfer based on Y channel information and a novel structural loss, composed of an encoder, a style transfer network, and a decoder. By introducing a structural loss to restrain the process of network training, the encoder can embed the gray-scale secret image into Y channel of the cover image and then generate steganographic image, while the decoder can directly extract the above secret image from a stylized stego image output by the style transfer network. The experimental results demonstrate that the proposed method can effectively recover the original secret information from the stylized stego image, and the PSNR of the extracted secret image and the original secret image can reach 23.4 and 27.29 for the gray-scale secret image and binary image with the size of 256×256, respectively, maintaining most of the details and semantics. Therefore, the proposed method can not only preserve most of the secret information embedded in a stego image during the stylization process, but also help to further hide secret information and avoid steganographic attacks to a certain extent due to the stylization of a stego image, thus protecting secret information like copyright. [ABSTRACT FROM AUTHOR]

Bombyx mori silk fibroin has potential applications in the biomedical field owing to its satisfactory biocompatibility. In the present work, a tyrosine-rich polypeptide (P) with the sequence of GKGYGGYGK was grafted onto fibroin molecules using a natural cross-linking agent of genipin (GP), aiming at improving the reactivity of the fibroin-based materials. Incubation of the polypeptide-grafted fibroin membrane was subsequently carried out, with a mushroom tyrosinase (MT) and a model functional macromolecule of ε-poly-l-lysine (ε-PL). The changes in the structure and composition of the silk fibroin before and after polypeptide grafting were examined by means of size exclusion chromatography and amino acid analysis. The results indicated that the polypeptide was covalently bonded to fibroin chains and evidently promoted the succeeding enzymatic coupling of ε-PL with fibroins, resulting in a higher content of ε-PL compared to the control. The obtained antibacterial activities against S. aureus and E. coli for the fibroin membrane treated with GP/P and MT/ε-PL was more satisfactory than others. Cytotoxicity testing reveals that polypeptide grafting did less impact on the biocompatibility of silk fibroins. The present work provides a novel method to improve the reactivity of silk fibroins and it can be utilized for bio-functionalization of silk fibroin. [ABSTRACT FROM AUTHOR]

During enzymatic modifications of silk fibroins, the accessibility of tyrosinases to the reactive sites was limited owing to the steric hindrance of tyrosine residues in the fibroin proteins. To improve the reactivity of silk fibroin, a tyrosine-containing peptide (TyrP) was covalently grafted onto the fibroin surfaces using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). Enzymatic oxidation of the modified fibroins was subsequently carried out with a mushroom tyrosinase, followed by coupling of ε-polylysine (ε-PL) with the generated o-quinone residues of silk fibroins. The efficacy of grafting reaction was examined by means of SDS-PAGE and amine acid analysis. The results indicated EDC treatment might cause the direct self-crosslinks of silk fibroins and TyrP-bridged cross-links of fibroin molecules as well, which led to a noticeable increase in the molecular weight of fibroin proteins. TyrP-grafted fibroins displayed higher reactivity compared to the untreated, and more ε-PL was bonded to the fibroin surfaces when incubating with tyrosinase, resulting in improved wettability and mechanical property. The presented work offers an efficient alternative for the enzymatic modification of the fibroin-based materials with tyrosinase. [ABSTRACT FROM AUTHOR]

Elastin has characteristics of elasticity, biological activity, and mechanical stability. In the present work, tyrosinase-mediated construction of a bioscaffold with silk fibroin and elastin was carried out, aiming at developing a novel medical biomaterial. The efficiency of enzymatic oxidation of silk fibroin and the covalent reaction between fibroin and elastin were examined by spectrophotometry, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and size exclusion chromatography (SEC). The properties of composite air-dried and nanofiber scaffolds were investigated. The results reveal that elastin was successfully bonded to silk fibroins, resulting in an increase in molecular weight of fibroin proteins. ATR-FTIR spectra indicated that tyrosinase treatment impacted the conformational structure of fibroin-based membrane. The thermal behaviors and mechanical properties of the tyrosinase-treated scaffolds were also improved compared with the untreated group. NIH/3T3 cells exhibited optimum densities when grown on the nanofiber scaffold, implying that the nanofiber scaffold has enhanced biocompatibility compared to the air-dried scaffold. A biological nanofiber scaffold constructed from tyrosinase-treated fibroin and elastin could potentially be utilized in biomedical applications. [ABSTRACT FROM AUTHOR]