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Oxidative stress damage caused by free radicals around the moist microenvironment of wound has been a clinical challenge in skin tissue healing. Here, a novel chitosan-based bioinspired asymmetric wound repair composite (BAWRC) film was designed by facilitated endogenous tissue engineering strategy through layer-by-layer self-assembly technology for accelerated wound healing. The asymmetric characteristics were skillfully reflected by two different functional layers: hydrophilic chitosan (CS)/silk fibroin (SF) repair layer, and a hydrophobic bacteriostatic tea tree oil (TTO) layer with a rough surface. Simultaneously, sodium ascorbate (SA)-entrapped poly (lactic-co-glycolic acid) (PLGA) microspheres are distributed homogeneously in the hydrophilic layer to induce antioxidant response for skin repair. The distinctive asymmetric structure of BAWRC film endows it with synergistic effects, i.e., protects against the risk of infection from the external environment and facilitates deep skin wound healing. Results show that the minimum inhibition and bactericidal concentration of the BAWRC film were 1.25 and 6.25 mg/mL, respectively, demonstrating good antibacterial properties. The content of biofilm formation was significantly reduced when the concentration of TTO exceeds 5 mg/mL, indicating TTO shows a positive effect on bacteriostasis. In addition, the DPPH rates of BAWRC film were up to 64.7 % after incubation for 12 h, which was ascribed to that the release of SA and TTO as a natural product could accelerate free radical scavenging. The BAWRC film exhibited excellent biocompatibility, and good antibacterial capacity, enhancing adhesion and proliferation of the NIH3T3 cell in vitro, further facilitating the healing of a rat full-thickness skin wounds model. Herein, this versatile asymmetric film possesses great potential for clinical management of wound healing and related soft tissue regeneration.

Photothermal therapy (PTT) has gained extensive interest in tumor treatments due to its non-invasive and low-toxic nature. However, the currently available photothermal agents (PTAs) mostly show unsatisfactory photothermal conversion efficiency (PCE). Besides, as a local cancer treatment modality, PTT fails to inhibit metastasis of tumors. To address these issues, in this study, two aza-boron-dipyrromethene (aza-BODIPY)-based organic photothermal agents (OPTAs), Fc-aza-BODIPY and TPA-aza-BODIPY, were rationally coined by introducing two strong electron-donating ferrocene (Fc) moieties and two triphenylamine (TPA) rotors, which could boost intramolecular photo-induced electron transfer (PET) and molecular rotation respectively, thereby improving the PCE of aza-BODIPY dyes. After encapsulation of hydrophobic Fc-aza-BODIPY (or TPA-aza-BODIPY) and quercetin with biodegradable PLGA and DSPE-mPEG2000, the resulting nanoparticles (FAQ NPs and TAQ NPs) showed excellent optical properties with PCE of ∼72.0% and ∼79.7% and specific tumor accumulations through enhanced permeability and retention (EPR) effects. Consequently, these two NPs possessed prominent antitumor effects under 880 nm laser irradiation. Moreover, both FAQ NPs and TAQ NPs loaded with quercetin could inhibit tumor metastasis efficiently. These two multifunctional nanomaterials integrating OPTAs and anti-metastasis agents constructed a cooperative treatment program, which may provide a potential opportunity for future clinical cancer treatment.

A highly efficient, green and sustainable protocol for rhodium(III)-catalyzed C-H alkylation of heterocycles with allylic alcohols has been achieved, which affords a series of β-aryl ketones in high yields. The reaction proceeds smoothly in water under air, and works well with heterocycles such as indoles, indolines, pyrroles and carbazoles. Notably, the expensive rhodium catalyst in water could be easily separated from the organic products, and reused for at least five times without loss of its catalytic activity and selectivity, which is a promising, green and sustainable pathway for the synthesis of β-aryl ketones. To the best of our knowledge, this is the first example for the reuse of expensive rhodium catalyst in water.

Osteoarthritis disease can easily lead to articular cartilage degeneration and subchondral bone damage, so the demand for suitable articular substitutes is gradually increasing. In order to simulate the complex environment of different layers in natural joint, we fabricate the continuous one-phase gradient scaffold. In the study, CS (chitosan) was modified with SH (sodium hyaluronate) and GO (graphene oxide) to form the whole scaffold. nHAP (Nano-hydroxyapatite) was in situ generated with gradient distribution in the scaffold. Continuous interface can better imitate the combination style of cartilage and subchondral bone at joint. The diverseness of scaffold’s different layer in water absorption/retention rate and mechanical property is similar to the difference of articular cartilage and subchondral bone. Meanwhile, the cell experiments demonstrated that the bionic scaffold can well promote the proliferation of bone marrow mesenchymal stem cell. Articular defect model further confirmed that the scaffold can better induce articular regeneration. Herein, the prepared scaffold might be an excellent candidate for endogenous articular repair.

In this work, the degradation of GaN-based packaged white light-emitting diodes (LEDs) caused by accelerated humidity testing will be investigated using non-destructive failure analysis tools, namely the mixed statistical distribution, spectrum analysis and parameters extraction. Physical failure analysis techniques are then used to verify and conclude the deduced failure mechanisms obtained by the non-destructive failure analysis tools.

Phase conjugation reflectivity greater than unity has been obtained in BSO in the wavelength range 570–590 nm via degenerate four-wave mixing in the usual retroreflection geometry by applying an audio-frequency ac-sinusoidal electric field. An intensity modulation at twice the field frequency in the generated signals was observed for the first time.