A Skin-Inspired Self-Adaptive System for Temperature Control During Dynamic Wound Healing.

The thermoregulating function of skin that is capable of maintaining body temperature within a thermostatic state is critical. However, patients suffering from skin damage are struggling with the surrounding scene and situational awareness. Here, we report an interactive self-regulation electronic system by mimicking the human thermos-reception system. The skin-inspired self-adaptive system is composed of two highly sensitive thermistors (thermal-response composite materials), and a low-power temperature control unit (Laser-induced graphene array). The biomimetic skin can realize self-adjusting in the range of 35-42 °C, which is around physiological temperature. This thermoregulation system also contributed to skin barrier formation and wound healing. Across wound models, the treatment group healed ~ 10% more rapidly compared with the control group, and showed reduced inflammation, thus enhancing skin tissue regeneration. The skin-inspired self-adaptive system holds substantial promise for next-generation robotic and medical devices.

Inhibitory effect and mechanism of algicidal bacteria on Chaetomorpha valida.

Chaetomorpha valida, filamentous green tide algae, poses a significant threat to both aquatic ecosystems and aquaculture. Vibrio alginolyticus Y20 is a new algicidal bacterium with an algicidal effect on C. valida. This study aimed to investigate the physiological and molecular responses of C. valida to exposure to V. alginolyticus Y20. The inhibitory effect of V. alginolyticus Y20 on C. valida was content dependent, with the lowest inhibitory content being 3 × 105 CFU mL-1. The microscopic results revealed that C. valida experienced severe morphological damage under the influence of V. alginolyticus Y20, with a dispersion of intracellular pigments. V. alginolyticus Y20 caused the decrease in chlorophyll-a content and Fv/Fm in C. valida. At the molecular level, V. alginolyticus Y20 downregulated the expression of genes related to photosynthetic pigment synthesis, light capture, and electron transport. Furthermore, V. alginolyticus Y20 induced oxidative damage to algal cells. The production of reactive oxygen species significantly increased after 11 days of exposure. Malondialdehyde content significantly increased, and the cell membranes were severely damaged by lipid peroxidation. The content of superoxide dismutase and peroxidase also markedly increased, whereas catalase content decreased significantly. Additionally, peroxisomes were inhibited due to the downregulation of PEX expression, leading to irreversible oxidative damage to algal cells. Our findings provided a new theoretical basis for exploring the interaction between algicidal bacteria and green tide algae at the molecular level.

Piezoresistive Fibers with Large Working Factors for Strain Sensing Applications.

Piezoresistive fibers with large working factors remain of great interest for strain sensing applications involving large strains, yet difficult to achieve. Here, we produced strain-sensitive fibers with large working factors by dip-coating nanocomposite piezoresistive inks on surface-modified polyether block amide (PEBA) fibers. Surface modification of neat PEBA fibers was carried out with polydopamine (PDA) while nanocomposite conductive inks consisted of styrene-ethylene-butylene-styrene (SEBS) elastomer and carbon black (CB). As such, the deposition of piezoresistive coatings was enabled through nonconventional hydrogen-bonding interactions. The resultant fibers demonstrated well-defined piezoresistive linear relationships, which increased with CB filler loading in SEBS. In addition, gauge factors decreased with increasing CB mass fractions from ∼15 to ∼7. Furthermore, we used the fatigue theory to predict the endurance limit (Ce) of our fibers toward resistance signal stability. Such a piezoresistive performance allowed us to explore the application of our fibers as strain sensors for monitoring the movement of finger joints.

Preparation and Characterization of Esterified Bamboo Flour by an In Situ Solid Phase Method.

Bamboo plastic composites have become a hot research topic and a key focus of research. However, many strong, polar, hydrophilic hydroxyl groups in bamboo flour (BF) results in poor interfacial compatibility between BF and hydrophobic polymers. Maleic anhydride-esterified (MAH-e-BF) and lactic acid-esterified bamboo flour (LA-e-BF) were prepared while using an in situ solid-phase esterification method with BF as the raw material and maleic anhydride or lactic acid as the esterifying agent. Fourier transform infrared spectroscopy results confirmed that BF esterification with maleic anhydride and lactic acid was successful, with the esterification degrees of MAH-e-BF and LA-e-BF at 21.04 ± 0.23% and 14.28 ± 0.17%, respectively. Esterified BF was characterized by scanning electron microscopy, contact angle testing, X-ray diffractometry, and thermogravimetric analysis. The results demonstrated that esterified BF surfaces were covered with graft polymer and the surface roughness and bonding degree of MAH-e-BF clearly larger than those of LA-e-BF. The hydrophobicity of esterified BF was significantly higher than BF and the hydrophobicity of MAH-e-BF was better than LA-e-BF. The crystalline structure of esterified BF showed some damage, while MAH-e-BF exhibited a greater decrease in crystallinity than LA-e-BF. Overall, the esterification reaction improved BF thermoplasticity, with the thermoplasticity of MAH-e-BF appearing to be better than LA-e-BF.