Self-Powered and Self-Healable Extraocular-Muscle-Like Actuator Based on Dielectric Elastomer Actuator and Triboelectric Nanogenerator.

Although dielectric elastomer actuators (DEAs) are promising artificial muscles for use as visual prostheses in patients with oculomotor nerve palsy (ONP), high driving voltage coupled with vulnerable compliant electrodes limits their safe long-term service. Herein, a self-healable polydimethylsiloxane compliant electrode based on reversible imine bonds and hydrogen bonds is prepared and coated on an acrylic ester film to develop a self-healable DEA (SDEA), followed by actuation with a high-output triboelectric nanogenerator (TENG) to construct a self-powered DEA (TENG-SDEA). Under 135.9 kV mm-1 , the SDEA exhibits an elevated actuated strain of 50.6%, comparable to the actuation under DC power. Moreover, the mechanically damaged TENG-SDEA displays a self-healing efficiency of over 90% for 10 cycles. The TENG ensures the safe using of TENG-SDEAs and an extraocular-muscle-like actuator with oriented motion ability integrated by several TENG-SDEAs is constructed. Additionally, the SDEA is directly used as a flexible capacitive sensor for real-time monitoring of the patient's muscle movement. Accordingly, a medical aid system based on a conjunction of the extraocular-muscle-like actuator and a flexible capacitive sensor is manufactured to help the patients suffering from ONP with physical rehabilitation and treatment.

Ozone-Induced Rapid and Green Synthesis of Polydopamine Coatings with High Uniformity and Enhanced Stability.

The development of green, controllable, and simplified pathways for rapid dopamine polymerization holds significant importance in the field of polydopamine (PDA) surface chemistry. In this study, a green strategy is successfully devised to accelerate and control the polymerization of dopamine through the introduction of ozone (O3 ). The findings reveal that ozone serves as an eco-friendly trigger, significantly accelerating the dopamine polymerization process across a broad pH range, spanning from 4.0 to 10.0. Notably, the deposition rate of PDA coatings on a silicon wafer reaches an impressive value of ≈64.8 nm h-1 (pH 8.5), which is 30 times higher than that of traditional air-assisted PDA and comparable to the fastest reported method. Furthermore, ozone exhibits the ability to accelerate dopamine polymerization even under low temperatures. It also enables control over the inhibition-initiation of the polymerization process by regulating the "ON/OFF" mode of the ozone gas. Moreover, the ozone-induced PDA coatings demonstrate exceptional characteristics, including high homogeneity, good hydrophilicity, and remarkable chemical and mechanical stability. Additionally, the ozone-induced PDA coatings can be rapidly and effectively deposited onto a wide range of substrates, particularly those that are adhesion-resistant, such as polytetrafluoroethylene (PTFE).

Clinical and muscle magnetic resonance image findings in patients with late-onset multiple acyl-CoA dehydrogenase deficiency.

BACKGROUND: Late-onset multiple acyl-coA dehydrogenase deficiency (MADD) is an autosomal recessive inherited metabolic disorder. It is still unclear about the muscle magnetic resonance image (MRI) pattern of the distal lower limb pre- and post-treatment in patients with late-onset MADD. This study described the clinical and genetic findings in a cohort of patients with late-onset MADD, and aimed to characterize the MRI pattern of the lower limbs. METHODS: Clinical data were retrospectively collected from clinic centers of Peking University People's Hospital between February 2014 and February 2018. Muscle biopsy, blood acylcarnitines, and urine organic acids profiles, and genetic analysis were conducted to establish the diagnosis of MADD in 25 patients. Muscle MRI of the thigh and leg were performed in all patients before treatment. Eight patients received MRI re-examinations after treatment. RESULTS: All patients presented with muscle weakness or exercise intolerance associated with variants in the electron transfer flavoprotein dehydrogenase gene. Muscle MRI showed a sign of both edema-like change and fat infiltration selectively involving in the soleus (SO) but sparing of the gastrocnemius (GA) in the leg. Similar sign of selective involvement of the biceps femoris longus (BFL) but sparing of the semitendinosus (ST) was observed in the thigh. The sensitivity and specificity of the combination of either "SO+/GA-" sign or "BFL+/ST-" sign for the diagnosis of late-onset MADD were 80.0% and 83.5%, respectively. Logistic regression model supported the findings. The edema-like change in the SO and BFL muscles were quickly recovered at 1 month after treatment, and the clinical symptom was also relieved. CONCLUSIONS: This study expands the clinical and genetic spectrums of late-onset MADD. Muscle MRI shows a distinct pattern in the lower limb of patients with late-onset MADD. The dynamic change of edema-like change in the affected muscles might be a potential biomarker of treatment response.