Stimuli-responsive hydrogel actuators have promising applications in various fields. However, the typical hydrogel actuation relies on the swelling and de-swelling process caused by osmotic-pressure ...changes, which is slow and normally requires the presence of water environment. Herein, we report a light-powered in-air hydrogel actuator with remarkable performances, including ultrafast motion speed (up to 1.6 m/s), rapid response (as fast as 800 ms) and high jumping height (~15 cm). The hydrogel is operated based on a fundamentally different mechanism that harnesses the synergetic interactions between the binary constituent parts, i.e. the elasticity of the poly(sodium acrylate) hydrogel, and the bubble caused by the photothermal effect of the embedded magnetic iron oxide nanoparticles. The current hydrogel actuator exhibits controlled motion velocity and direction, making it promising for a wide range of mobile robotics, soft robotics, sensors, controlled drug delivery and other miniature device applications.
Abstract
Microcatheters have enabled diverse minimally invasive endovascular operations and notable health benefits compared with open surgeries. However, with tortuous routes far from the arterial ...puncture site, the distal vascular regions remain challenging for safe catheter access. Therefore, we propose a wireless stent-shaped magnetic soft robot to be deployed, actively navigated, used for medical functions, and retrieved in the example M4 segment of the middle cerebral artery. We investigate shape-adaptively controlled locomotion in phantoms emulating the physiological conditions here, where the lumen diameter shrinks from 1.5 mm to 1 mm, the radius of curvature of the tortuous lumen gets as small as 3 mm, the lumen bifurcation angle goes up to 120
°
, and the pulsatile flow speed reaches up to 26 cm/s. The robot can also withstand the flow when the magnetic actuation is turned off. These locomotion capabilities are confirmed in porcine arteries ex vivo. Furthermore, variants of the robot could release the tissue plasminogen activator on-demand locally for thrombolysis and function as flow diverters, initiating promising therapies towards acute ischemic stroke, aneurysm, arteriovenous malformation, dural arteriovenous fistulas, and brain tumors. These functions should facilitate the robot’s usage in new distal endovascular operations.
was originally isolated from the 'Wangkumbae' pear (
Nakai), and it encodes for cinnamyl alcohol dehydrogenase (CAD), which is a key enzyme in the lignin biosynthesis pathway. In order to verify the ...function of
, transgenic tomato (
) 'Micro-Tom' plants were generated using over-expression constructs via the agrobacterium-mediated transformation method. The results showed that the
over-expression transgenic tomato plant had a strong growth vigor. Furthermore, these
over-expression transgenic tomato plants contained a higher lignin content and CAD enzymatic activity in the stem, leaf and fruit pericarp tissues, and formed a greater number of vessel elements in the stem and leaf vein, compared to wild type tomato plants. This study clearly indicated that overexpressing
increased the lignin deposition of transgenic tomato plants, and thus validated the function of
in lignin biosynthesis.
Wireless small-scale soft-bodied devices are capable of precise operation inside confined internal spaces, enabling various minimally invasive medical applications. However, such potential is ...constrained by the small output force and low work capacity of the current miniature soft actuators. To address this challenge, we report a small-scale soft actuator that harnesses the synergetic interactions between the coiled artificial muscle and radio frequency-magnetic heating. This wirelessly controlled actuator exhibits a large output force (~3.1 N) and high work capacity (3.5 J/g). Combining this actuator with different mechanical designs, its tensile and torsional behaviors can be engineered into different functional devices, such as a suture device, a pair of scissors, a driller, and a clamper. In addition, by assuming a spatially varying magnetization profile, a multilinked coiled muscle can have both magnetic field-induced bending and high contractile force. Such an approach could be used in various future untethered miniature medical devices.
Abstract
Light-driven actuators have great potential in different types of applications. However, it is still challenging to apply them in flying devices owing to their slow response, small ...deflection and force output and low frequency response. Herein, inspired by the structure of vine maple seeds, we report a helicopter-like rotary flying photoactuator (in response to 0.6 W/cm
2
near-infrared (NIR) light) with ultrafast rotation (~7200 revolutions per minute) and rapid response (~650 ms). This photoactuator is operated based on a fundamentally different mechanism that depends on the synergistic interactions between the photothermal graphene and the hygroscopic agar/silk fibroin components, the subsequent aerodynamically favorable airscrew formation, the jet propulsion, and the aerodynamics-based flying. The soft helicopter-like photoactuator exhibits controlled flight and steering behaviors, making it promising for applications in soft robotics and other miniature devices.
In this study, the influencing factors of Hantzsch reaction have been investigated and a simple spectrofluorimetric method for the determination of acyclovir, ganciclovir, famciclovir, oxiracetam, ...and prazosin hydrochloride developed. The proposed method is based on the Hantzsch reaction of acetyl acetone-formaldehyde reagent with drugs. The results indicate that the drugs fluorescence in H
2
O is inhibited and enhanced in DMSO.
Rural tourism (RT) and cloud computing are important forces in implementing the rural revitalization strategy, and they play a key role in accelerating agriculture and rural area modernization, ...urban-rural integration, poverty alleviation in impoverished areas, and so on. RT’s development is influenced by a variety of factors due to its high industrial relevance and strong driving function. The development of RT is examined from the perspectives of data mining and cloud computing in this paper, and a data mining model of the RT development’s driving mechanism is built. Five driving modes of RT development are simulated by adjusting the parameters of industrial economy, resources, environment, and social culture in H city as an example. The simulation results are compared and analyzed in various modes. Finally, the coordinated development model of industrial economy, social culture, resources, and environment is found to be the best model of RT development in H city, and countermeasures and suggestions for RT development in H city are proposed based on the analysis results.
A phototactic liquid micromotor Zhang, Dongmei; Sun, Yunyu; Li, Mingtong ...
Journal of materials chemistry. C, Materials for optical and electronic devices,
2018, Letnik:
6, Številka:
45
Journal Article
Recenzirano
In recent years, micromotors, which possess unique autonomous moving properties inside a solution, have shown great potential in a variety of applications ranging from environmental remediation to ...the biomedical field. However, most of the micromotors are based on solid materials. In this paper, we report a liquid (water, serum or urine) micromotor, which exhibits self-propelling behavior in an oil solution upon white light irradiation. Interestingly, the liquid micromotor exhibits both positive and negative phototaxis, which relies on the photochromism of the surrounding spiropyran molecules dissolved in oil or the thermal effect, respectively. In addition, light shows great versatility in controlling the motion behavior of the liquid micromotor so that it can move in a desired fashion. Furthermore, we have demonstrated that the liquid-based micromotor has great advantages over the solid ones. It not only enables fusion and reaction between different reactant-loaded liquid micromotors based on the combined positive and negative phototaxis, but also allows controlled cargo capture and transportation. We thus believe the liquid micromotor reported in the current study may have potential applications in various fields such as glucose detection.
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•B. subtilis co-expressing ADH and ALDH was successfully constructed.•It decreased increase of blood alcohol content in alcohol-treated mice.•It restored the microbial composition, in ...particular pathogenic H. hepaticus.•It could act as a novel candidate probiotic to alleviate acute alcoholic liver injury.
Alcohol consumption increases the risk of liver disease. Here, we investigated the effects of Bacillus subtilis co-expressing alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH), key enzymes in ethanol degradation, on acute alcohol-induced liver injury. Recombinant B. subtilis significantly alleviated alcohol-induced increase in the liver index, blood alcohol content, and serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activities. Furthermore, administration of ADH/ALDH-expressing B. subtilis inhibited lipid peroxidation and oxidative stress in the liver of alcohol-treated mice as evidenced by significant reduction of malondialdehyde and induction of total antioxidant capacity and glutathione and superoxide dismutase levels. Caecal microbiota diversity analysis indicated that administration of recombinant B. subtilis reversed alcohol-induced decrease in Firmicutes and increase in Proteobacteria, in particular pathogenic Helicobacter hepaticus, restoring the microbial composition in alcohol-treated mice. In conclusion, recombinant B. subtilis expressing ADH and ALDH could act as a novel candidate probiotic for prevention of alcohol-induced acute liver injury.