Electrohydrodynamic Printing of a Dielectric Elastomer Actuator and Its Application in Tunable Lenses

Optical lenses driven by dielectric elastomer (DE) actuators with tunable focal lengths are presented here. They are inspired by the architecture of the crystalline lens and the ciliary muscle of the human eye and have prompted a growing interest. The most commonly used DEs in tunable lenses have often required highly transparent films and also the need to encapsulate clear liquid silicone to act as the lens. There is a restriction on the properties of the tunable lens imposed by materials limitations. Here, the fabrication of a fully 3D printed tunable lens with an inhomogeneous structure is described. It exhibited a 29% change in focal length from 33.6 mm to 26.1 mm under a dynamic driving voltage signal control. Furthermore, it displayed excellent stability when the focal length was tuned from far to near (30.1 mm to 25.3 mm) for 200 cycles. The tunable lens obtained mimics the working principle of the human eye in auto adjusting the focal length and has evident potential applications in imaging, information storage, beam steering and bifocal technology

Anticonvulsant activities of α-asaronol ((E)-3'-hydroxyasarone), an active constituent derived from α-asarone.

BACKGROUND: Epilepsy is one of chronic neurological disorders that affects 0.5-1.0% of the world's population during their lifetime. There is a still significant need to develop novel anticonvulsant drugs that possess superior efficacy, broad spectrum of activities and good safety profile. METHODS: α-Asaronol and two current antiseizure drugs (α-asarone and carbamazepine (CBZ)) were assessed by in vivo anticonvulsant screening with the three most employed standard animal seizure models, including maximal electroshock seizure (MES), subcutaneous injection-pentylenetetrazole (PTZ)-induced seizures and 3-mercaptopropionic acid (3-MP)-induced seizures in mice. Considering drug safety evaluation, acute neurotoxicity was assessed with minimal motor impairment screening determined in the rotarod test, and acute toxicity was also detected in mice. RESULTS: In our results, α-asaronol displayed a broad spectrum of anticonvulsant activity (ACA) and showed better protective indexes (PI = 11.11 in MES, PI = 8.68 in PTZ) and lower acute toxicity (LD50 = 2940 mg/kg) than its metabolic parent compound (α-asarone). Additionally, α-asaronol displayed a prominent anticonvulsant profile with ED50 values of 62.02 mg/kg in the MES and 79.45 mg/kg in the sc-PTZ screen as compared with stiripentol of ED50 of 240 mg/kg and 115 mg/kg in the relevant test, respectively. CONCLUSION: The results of the present study revealed α-asaronol can be developed as a novel molecular in the search for safer and efficient anticonvulsants having neuroprotective effects as well as low toxicity. Meanwhile, the results also suggested that α-asaronol has great potential to develop into another new aromatic allylic alcohols type anticonvulsant drug for add-on therapy of Dravet's syndrome

Quantifying the effects of external factors on the behavior of vertical wicking in a warp stretch woven fabric

Wicking ability of textiles is a key indicator in determining the physiological comfort provided by a fabric. The property is shaped by various factors internal and external to the fabric. Herein, the effects of some external factors such as the degree of (fabric) extension, the wetting liquid’s temperature and relative humidity on the vertical wicking behavior of a previously prepared warp stretch woven fabric were investigated. The fabric, which could be reversibly extended up to 60%, was prepared using a nylon/spandex air-covered yarn in the warp and cotton yarn in the weft. The results indicated that these external factors had a great influence on the vertical wicking equilibrium height with the degree of fabric extension having a more pronounced effect compared with the other two factors. Furthermore, extension and relative humidity were negatively related to the height of the vertical wicking, whilst an increase in liquid temperature resulted in an increase in vertical wicking height. The underlying mechanisms associated with these effects were examined using a specially constructed test chamber and tensioning device. The experimental data were also verified using the classical Laughlin-Davies model, and the results demonstrated the proposed wicking model could be used to predict the changes in fabric wicking height. These findings provide a more in-depth understanding of the wicking behavior of stretchable textiles in a comprehensive and objective manner

Impact behavior of nylon kernmantle ropes for high-altitude fall protection

Aiming at the problem that the existing rope falling device can only detect the impact force and cannot synchronously detect the impact displacement, this paper introduces a large-range high-precision displacement sensor and constructs a rope impact force-displacement detection device. Taking the nylon kernmantle rope for high-altitude fall protection commonly used in aerial work and rock climbing as the research object, the impact response behavior of the rope when drop mass is dropped once and repeatedly is systematically studied, and the impact force and impact displacement are discussed. Further, the evolution of the elastic modulus of the rope is discussed and this could provide theoretical support for the design of the impact-resistant rope structure and the rope impact protection

Discovery of anti-inflammatory dihydroxylated phenolic acids in patients with severe cardiac symptoms and conditions associated with inflammation and hypoxia

Our initial studies detected elevated levels of 3,4-dihydroxyphenyllactic acid (DHPLA) in urine samples of patients with severe cardiac symptoms when compared with healthy subjects. In view of the reported anti-inflammatory properties of DHPLA and related dihydroxylated phenolic acids (DPAs), we embarked on a multi-centre investigation to establish the possible pathophysiological significance and therapeutic implications of these findings. Chinese and Caucasian patients with severe cardiac symptoms and those being treated for conditions associated with inflammation (WBC ≥ 10×109/L or hsCRP ≥ 3.0 mg/L) and/or hypoxia (PaO2 ≤ 75 mmHg) were enrolled, their urine samples were analyzed by HPLC, HPLC-MS, GC-MS and biotransformation assays. DHPLA was detected in urine samples of patients, but undetectable in healthy volunteers. Dynamic monitoring of inpatients undergoing treatment showed their DHPLA levels declined in proportion to their clinical improvement. Proteus vulgaris and P. mirabilis were significantly more abundant in DHPLA-positive patients’ fecal samples than healthy volunteers. In culture, these bacteria were capable of reversible interconversion between DOPA and DHPLA. Furthermore, porcine and rodent organs were able to metabolize DOPA to DHPLA and related phenolic acids. The elevated levels of DHPLA in these patients suggest anti-inflammatory DPAs are generated de novo as part of a human’s defense mechanism against disease. Given that DHPLA isolated from Radix Salvia miltiorrhizae has multi-dimensional pharmacological activities, these data demonstrate not only scientific basis of the ethnopharmacological uses of this medicinal plant but also highlight the therapeutic potential of endogenous, natural or synthetic DPAs and their derivatives in humans