Reinforced Nacre-Like MXene/Sodium Alginate Composite Films for Bioinspired Actuators Driven by Moisture and Sunlight.

MXene-based soft actuators have attracted increasing attention and shown competitive performance in various intelligent devices such as supercapacitors, bionic robots and artificial muscles. However, the development of robust MXene-based actuators with multi-stimuli responsiveness remains challenging. In this study, a nacre-like structure soft actuator based on MXene and sodium alginate (SA) composite films is prepared using a straightforward solvent casting self-assembly method, which not only enhances the mechanical performance (tensile strength of 72 MPa) but also diversifies the stimuli responsiveness of the material. The composite actuators can be powered by external stimuli from renewable energy sources, from moisture inducing a maximum bending angle of 190 degrees at a relative humidity (RH) of 91%, and sunlight irradiation generating a maximum curvature of 1.45 cm-1 under 100 mW cm-2. The feasibility of practical applications, including moisture-responsive flowers and walkers, sunlight-responsive oscillators, and smart switches, is demonstrated through comprehensive experimental characterization and performance evaluation. The work presented here provides insight into the design of robust actuators via the utilization and conversion of environmentally renewable energy sources.

The critical role of hydroxyl groups in water vapor sensing of graphene oxide.

Excellent adsorption of water vapor on the surface of graphene oxide (GO), which contains several inherited functional groups, leads to the development of improved humidity monitoring systems that can urgently meet the high industrial demand. In this study, we fabricated a GO-based humidity sensor and investigated the influence of hydroxyl group concentration on its performance. The sensor exhibited excellent humidity sensing performance in terms of sensitivity (sensor response ∼40 for 90% RH), selectivity, stability (both long-term and short-term) and reaction time (τ res = 8.5 s and τ rec = 13 s). Additionally, this sensor does not require external power consumption for heating; thus, the aforementioned performance (recorded at room temperature) with an applied voltage of 0.1 V can significantly reduce the power/energy consumption to about ∼1.314 × 10-4 kW h per year. In the future, this type of sensor can be integrated into smart humidity monitoring systems to not only monitor but also control the humidity levels on a specific application area. Based on complementary characterization techniques, such as XRD, AFM, Raman and electrical measurement, here, we propose a physical-chemical sensing model to elucidate the aforementioned sensor characteristics.

Inhibition of keratin 17 expression with antisense and RNAi strategies: exploring novel therapy for psoriasis.

Psoriasis is now considered to be a chronic, immune-mediated and inflammatory skin disease. As the precise cause of psoriasis remains unknown, its treatment is challenging for dermatologists. Keratin 17 (K17), an intermediate filament protein, is highly expressed in psoriatic lesions, while not normally expressed in healthy epidermis. Studies have suggested that K17 plays a role in the pathogenesis of psoriasis. However, no study has been performed to determine the potential application of K17 down-regulation as a treatment option for psoriatic lesions. We hypothesized that anti-K17 interference may suppress the development and progression of psoriasis and potentially serve as a novel strategy for the treatment of psoriasis. Therefore, we down-regulated and silenced K17 gene expression in keratinocytes (KCs) using antisense and RNA interference (RNAi) techniques. We found that K17-specific antisense oligonucleotides (ASODN) or siRNAs inhibited proliferation and induced apoptosis in KCs as well as down-regulated K17 expression at both mRNA and protein levels. For our in vivo study, we constructed the SCID-hu xenogeneic transplantation psoriasis mouse model by grafting psoriatic lesions onto SCID mice and topically applied K17-specific ASODN and liposome-encapsulated siRNA to the grafts. We observed morphological and histological improvement in the treated psoriatic grafts. As a result, K17 mRNA and protein expression was significantly decreased in the grafts of the mouse model. Taken together, we conclude that anti-K17 therapy is an effective treatment option for psoriasis, and the K17 molecule, as a new target, may hold tremendous potential for the treatment of psoriasis in the future.

Optimal frequency of treatment with the 308-nm excimer laser for vitiligo on the face and neck.

OBJECTIVES: This study was designed to determine the optimal treatment frequency with the 308-nm excimer laser for vitiligo and identify key clinical variable(s) associated with treatment efficacy at the optimal frequency. BACKGROUND DATA: Optimal clinical parameters for excimer laser treatment of vitiligo have not been fully determined. Data about the influence on treatment frequency of different clinical variables of vitiligo are needed to facilitate effective treatment regimens. METHODS: A total of 187 patients were treated with the 308-nm excimer laser for 20 sessions at different frequencies (0.5, 1.0, 2.0, and 3.0 per week). The repigmentation rate was graded on a six-point scale and was blindly evaluated by independent physicians. RESULTS: The final percentage of repigmentation for group 0.5 was statistically lower than those for group 1.0, 2.0, and 3.0, and percentages of final levels of repigmentation among these three groups were not statistically different. The clinical variables showed no statistical differences in the final repigmentation effect. Repigmentation occurred fastest with treatment frequencies of 2.0 and 3.0 and there was no statistically significant difference between them. The onset of repigmentation correlated with the area of vitiliginous patches treated, not with the other clinical variables. CONCLUSIONS: The 308-nm excimer laser is effective for therapy to treat vitiligo on the face and neck. The ultimate laser-induced repigmentation effect does not correlate with treatment frequency and repigmentation occurs faster with treatment frequencies of 2.0 and 3.0 than that of 1.0. It appears that the onset of repigmentation correlates with the total area of vitiliginous patches and the optimal treatment frequency. Monitored studies on a larger population with long-term follow-up would be needed to confirm and extend our findings.

[Reactivity of IgG class of anti-keratin autoantibodies in healthy human sera].

AIM: To analyze the reaction patterns of IgG class of anti-keratin autoantibodies (AK auto Abs) in normal human sera before and after purification, and to explore the effects of serum non-IgG components on the reaction patterns of IgG class of AK auto Abs. METHODS: Titers of IgG AK auto Abs in healthy human sera before and after purification were measured by indirect ELISA, and the reaction patterns of the AK auto Abs to a group of keratins with different relative molecule mass were analysed by Western blot. RESULTS: Titers of purified IgG class of AK auto Abs were higher than those of unpurified sera. Western blot analysis showed purified AK auto Abs recognized more keratins with stronger avidity than unpurified AK auto Abs. The reaction patterns of AK auto Abs from different individuals tended to be homogenous after purification. CONCLUSION: The reaction patterns of serum IgG class of AK auto Abs are influenced by some non-IgG components in sera. The homogeneity of reaction patterns of AK auto Abs from different individuals indicated that B cells producing IgG class of AK auto Abs may be selected by a set of conserved self-antigens, and this process may have no relationship with an individual's exposure to foreign antigens.