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1.
Apoptosis ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38743191

RESUMO

Lenvatinib is a commonly used first-line drug for the treatment of advanced hepatocellular carcinoma (HCC). However, its clinical efficacy is limited due to the drug resistance. EVA1A was a newly identified tumor suppressor, nevertheless, the impact of EVA1A on resistance to lenvatinib treatment in HCC and the potential molecular mechanisms remain unknown. In this study, the expression of EVA1A in HCC lenvatinib-resistant cells is decreased and its low expression was associated with a poor prognosis of HCC. Overexpression of EVA1A reversed lenvatinib resistance in vitro and in vivo, as demonstrated by its ability to promote cell apoptosis and inhibit cell proliferation, invasion, migration, EMT, and tumor growth. Silencing EVA1A in lenvatinib-sensitive parental HCC cells exerted the opposite effect and induced resistance to lenvatinib. Mechanistically, upregulated EVA1A inhibited the PI3K/AKT/MDM2 signaling pathway, resulting in a reduced interaction between MDM2 and p53, thereby stabilizing p53 and enhancing its antitumor activity. In addition, upregulated EVA1A suppressed the PI3K/AKT/mTOR signaling pathway and promoted autophagy, leading to the degradation of mutant p53 and attenuating its oncogenic impact. On the contrary, loss of EVA1A activated the PI3K/AKT/MDM2 signaling pathway and inhibited autophagy, promoting p53 proteasomal degradation and mutant p53 accumulation respectively. These findings establish a crucial role of EVA1A loss in driving lenvatinib resistance involving a mechanism of modulating PI3K/AKT/p53 signaling axis and suggest that upregulating EVA1A is a promising therapeutic strategy for alleviating resistance to lenvatinib, thereby improving the efficacy of HCC treatment.

2.
Biosens Bioelectron ; 257: 116299, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38636318

RESUMO

Skin-interfaced microfluidic patch has become a reliable device for sweat collection and analysis. However, the intractable problems of emptying the microchannel for reuse, and the channel's volumetric capacity limited by the size of the patch, directly hinder the practical application of sweat sensors. Herein, we report an adaptively resettable microfluidic sweat patch (Art-Sweat patch) capable of continuously monitoring both sweat rate (0.2-4.0 µL min-1) and total ionic charge concentration (10-200 mmol L-1). We develop a platform with a vertical and horizontal microchannel combined strategy, enabling repeatedly filling sweat and emptying the microchannel for autonomously resetting and detecting. The variation in the emptied volume is designed to be adaptively identified by the sensor, resulting in enhanced stability and an enlarged volumetric capacity of over 300 µL. By integrating with self-designed wireless transmission modules, the proposed Art-Sweat patch shows product-level wearability and high performance in monitoring variations in regional sweat rate and concentration for hydration status assessment.


Assuntos
Técnicas Biossensoriais , Eletrólitos , Suor , Suor/química , Humanos , Técnicas Biossensoriais/instrumentação , Eletrólitos/química , Dispositivos Eletrônicos Vestíveis , Desenho de Equipamento , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação
3.
Metabolism ; 155: 155905, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38548128

RESUMO

CD36, a scavenger receptor B2 that is dynamically distributed between cell membranes and organelle membranes, plays a crucial role in regulating lipid metabolism. Abnormal CD36 activity has been linked to a range of metabolic disorders, such as obesity, nonalcoholic fatty liver disease, insulin resistance and cardiovascular disease. CD36 undergoes various modifications, including palmitoylation, glycosylation, and ubiquitination, which greatly affect its binding affinity to various ligands, thereby triggering and influencing various biological effects. In the context of tumors, CD36 interacts with autophagy to jointly regulate tumorigenesis, mainly by influencing the tumor microenvironment. The central role of CD36 in cellular lipid homeostasis and recent molecular insights into CD36 in tumor development indicate the applicability of CD36 as a therapeutic target for cancer treatment. Here, we discuss the diverse posttranslational modifications of CD36 and their respective roles in lipid metabolism. Additionally, we delve into recent research findings on CD36 in tumors, outlining ongoing drug development efforts targeting CD36 and potential strategies for future development and highlighting the interplay between CD36 and autophagy in the context of cancer. Our aim is to provide a comprehensive understanding of the function of CD36 in both physiological and pathological processes, facilitating a more in-depth analysis of cancer progression and a better development and application of CD36-targeting drugs for tumor therapy in the near future.


Assuntos
Autofagia , Antígenos CD36 , Progressão da Doença , Metabolismo dos Lipídeos , Neoplasias , Humanos , Antígenos CD36/metabolismo , Antígenos CD36/fisiologia , Autofagia/fisiologia , Metabolismo dos Lipídeos/fisiologia , Neoplasias/metabolismo , Neoplasias/patologia , Animais
4.
Adv Mater ; 36(15): e2310260, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38116707

RESUMO

The evaporation-induced hydrovoltaic effect based on ion-selective nanochannels can theoretically be employed for high-performance ion sensing; yet, the indeterminate ion-sensing properties and the acquisition of high sensing performance are rarely explored. Herein, a controllable nanochannel regulation strategy for flexible hydrovoltaic devices with highly sensitive ion-sensing abilities is presented across a wide concentration range. By multiple dip-coating of silk fibroin (SF) on an electrospinning nylon-66 nanofiber (NNF) film, the surface polarity enhancement, the fibers size regulation with a precision of ≈25 nm, and the nanostructure firm binding are achieved simultaneously. The resultant flexible freestanding hydrovoltaic device exhibits an open circuit voltage up to 4.82 V in deionized water, a wide ion sensing range of 10-7 to 100 m, and ultrahigh sensitivity as high as 1.37 V dec-1, which is significantly higher than the sensitivity of the traditional solid-contact ion-selective electrodes (SC-ISEs). The fabricated flexible ion-sensitive hydrovoltaic device is successfully applied for wearable human sweat electrolyte sensing and for environmental trace-ion monitoring, thereby confirming the potential application of the hydrovoltaic effect for ion sensing.

5.
Adv Mater ; 35(40): e2304099, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37401733

RESUMO

The lack of a strong binding mechanism between nanomaterials severely restricts the advantages of the evaporation-driven hydrovoltaic effect in wearable sensing electronics. It is a challenging task to observably improve the mechanical toughness and flexibility of hydrovoltaic devices to match the wearable demand without abandoning the nanostructures and surface function. Here, a flexible tough polyacrylonitrile/alumina (PAN/Al2 O3 ) hydrovoltaic coating with both good electricity generation (open-circuit voltage, Voc  ≈ 3.18 V) and sensitive ion sensing (2285 V M-1 for NaCl solutions in 10-4 to 10-3  m) capabilities is developed. The porous nanostructure composed of Al2 O3 nanoparticles is firmly locked by the strong binding effect of PAN, giving a critical binding force 4 times that of Al2 O3 film to easily deal with 9.92 m s-1 strong water-flow impact. Finally, skin-tight and non-contact device structures are proposed to achieve wearable multifunctional self-powered sensing directly using sweat. The flexible tough PAN/Al2 O3 hydrovoltaic coating breaks through the mechanical brittleness limitation and broadens the applications of the evaporation-induced hydrovoltaic effect in self-powered wearable sensing electronics.


Assuntos
Nanoestruturas , Dispositivos Eletrônicos Vestíveis , Eletrônica , Fenômenos Mecânicos , Eletricidade
6.
Biosens Bioelectron ; 237: 115504, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37406481

RESUMO

Epidermal microfluidic devices are continuously being developed for efficient sweat collection and sweat rate detection. However, most microfluidic designs ignore the use of airtight/adhesive substrate will block the natural perspiration of the covered sweat pores, which will seriously affect normal sweat production and long-term wearable comfort. Herein, we present a Janus textile-embedded microfluidic sensor platform with high breathability and directional sweat permeability for synchronous sweat rate and total electrolyte concentration detection. The device consists of a hollowed-out serpentine microchannel with interdigital electrodes and Janus textile. The dual-mode signal of the sweat rate (0.2-4.0 µL min-1) and total ionic charge concentration (10-200 mmol L-1) can be obtained synchronously by decoupling conductance step signals generated when sweat flows through alternating interdigitated spokes at equal intervals in the microchannel. Meanwhile, the hollowed-out microchannel structure significantly reduces the coverage area of the sensor on the skin, and the Janus textile-embedded device ensures a comfortable skin/device interface (fewer sweat pores are blocked) and improves breathability (503.15 g m-2 d-1) and sweat permeability (directional liquid transportation) during long-term monitoring. This device is washable and reusable, which shows the potential to integrate with clothing and smart textile, and thus facilitate the practicality of wearable sweat sensors for personalized healthcare.


Assuntos
Técnicas Biossensoriais , Suor , Suor/química , Microfluídica , Eletrólitos , Têxteis
7.
Nanomicro Lett ; 15(1): 139, 2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37245163

RESUMO

Hydrogels offer tissue-like softness, stretchability, fracture toughness, ionic conductivity, and compatibility with biological tissues, which make them promising candidates for fabricating flexible bioelectronics. A soft hydrogel film offers an ideal interface to directly bridge thin-film electronics with the soft tissues. However, it remains difficult to fabricate a soft hydrogel film with an ultrathin configuration and excellent mechanical strength. Here we report a biological tissue-inspired ultrasoft microfiber composite ultrathin (< 5 µm) hydrogel film, which is currently the thinnest hydrogel film as far as we know. The embedded microfibers endow the composite hydrogel with prominent mechanical strength (tensile stress ~ 6 MPa) and anti-tearing property. Moreover, our microfiber composite hydrogel offers the capability of tunable mechanical properties in a broad range, allowing for matching the modulus of most biological tissues and organs. The incorporation of glycerol and salt ions imparts the microfiber composite hydrogel with high ionic conductivity and prominent anti-dehydration behavior. Such microfiber composite hydrogels are promising for constructing attaching-type flexible bioelectronics to monitor biosignals.

8.
Biosens Bioelectron ; 210: 114351, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35569269

RESUMO

Epidermal microfluidic devices with long microchannels have been developed for continuous sweat analysis, which are crucial to assess personal hydration status and underlying health conditions. However, the flow resistance in long channels and the ionic concentration variation significantly affect the accuracy of both the sweat rate and electrolyte concentration measurements. Herein, we present a novel fluidic-controlled wearable platform for synchronously dropwise-detecting the sweat rate and total electrolyte concentration. The unconventional platform consisting of a vertically shortened channel, a pair of embedded electrodes and an absorption layer, is designed to minimize the flow resistance and transform sweat fluidics into uniform micro-droplets for chronological and dropwise detection. Real-time sweat conductance is decoupled from a square-wave-like curve, where the sweat rate and electrolyte concentration can be derived from the interval time and peak value, respectively. Flexible and wearable band devices are demonstrated to show their potential application for hydration status assessment during exercises.


Assuntos
Técnicas Biossensoriais , Dispositivos Eletrônicos Vestíveis , Eletrólitos , Dispositivos Lab-On-A-Chip , Suor
9.
ACS Appl Mater Interfaces ; 14(22): 25093-25103, 2022 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-35606333

RESUMO

Articular cartilage, which exhibits toughness and ultralow friction even under high squeezing pressures, plays an important role in the daily movement of joints. However, joint soft tissue lesions or injuries caused by diseases, trauma, or human functional decline are inevitable. Poly(vinyl alcohol) (PVA) hydrogels, which have a water content and compressive strength similar to those of many tissues and organs, have the potential to replace tough connective tissues, including cartilage. However, currently, PVA hydrogels are not suitable for complex dynamic environments and lack rebound resilience, especially under long-term or multicycle mechanical loads. Inspired by biological tissues that exhibit increased mechanical strength after swelling, we report a tough engineered hydrogel (TEHy) fabricated by swelling and freeze-thaw methods with a high compressive strength (31 MPa), high toughness (1.17 MJ m-3), a low friction coefficient (0.01), and a low energy loss factor (0.22). Notably, the TEHy remained remarkably resilient after 100 000 cycles of contact extrusion and remains intact after being compressed by an automobile with a weight of approximately 1600 kg. The TEHy also exhibited excellent water swelling resistance (volume and weight changes less than 5%). Moreover, skeletal muscle cells were able to readily attach and proliferate on the surface of TEHy-6, suggesting its outstanding biocompatibility. Overall, this swelling and freeze-thaw strategy solves the antifatigue and stability problems of PVA hydrogels under large static loads (>10 000 N) and provides an avenue to fabricate engineering hydrogels with strong antifatigue and antiswelling properties and ultralow friction for potential use as biomaterials in tissue engineering.


Assuntos
Cartilagem Articular , Hidrogéis , Materiais Biocompatíveis , Força Compressiva , Humanos , Álcool de Polivinil , Água
10.
Nat Commun ; 13(1): 1043, 2022 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-35210414

RESUMO

Restricted ambient temperature and slow heat replenishment in the phase transition of water molecules severely limit the performance of the evaporation-induced hydrovoltaic generators. Here we demonstrate a heat conduction effect enhanced hydrovoltaic power generator by integrating a flexible ionic thermoelectric gelatin material with a porous dual-size Al2O3 hydrovoltaic generator. In the hybrid heat conduction effect enhanced hydrovoltaic power generator, the ionic thermoelectric gelatin material can effectively improve the heat conduction between hydrovoltaic generator and near environment, thus increasing the water evaporation rate to improve the output voltage. Synergistically, hydrovoltaic generator part with continuous water evaporation can induce a constant temperature difference for the thermoelectric generator. Moreover, the system can efficiently achieve solar-to-thermal conversion to raise the temperature difference, accompanied by a stable open circuit voltage of 6.4 V for the hydrovoltaic generator module, the highest value yet.

11.
Small ; 18(12): e2106477, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35092161

RESUMO

Epidermal electronics have been developed with gas/sweat permeability for long-term wearable electrophysiological monitoring. However, the state-of-the-art breathable epidermal electronics ignore the sweat accumulation and immersion at the skin/device interface, resulting in serious degradation of the interfacial conformality and adhesion, leading to signal artifacts with unstable and inaccurate biopotential measurements. Here, the authors present an all-nanofiber-based Janus epidermal electrode endowed with directional sweat transport properties for artifact-free biopotential monitoring. The designed Janus multilayered membrane (≈15 µm) of superhydrophilic-hydrolyzed-polyacrylonitrile (HPAN)/polyurethane (PU)/Ag nanowire (AgNW) can quickly (less than 5 s) drive sweat away from the skin/electrode interface while resisting its penetration in the reverse direction. Along with the medical adhesive (MA)-reinforced junction-nodes, the adhesion strength among the heterogeneous interfaces can be greatly enhanced for robust mechanical-electrical stability. Therefore, their measured on-body electromyography (EMG) and electrocardiography (ECG) signals are free of sweat artifacts with negligible degradation and baseline drift compared to commercial Ag/AgCl gel electrodes and hydrophilic textile electrodes. This work paves a way to design novel directional-sweat-permeable epidermal electronics that can be conformally attached under sweaty conditions for long-term biopotential monitoring and shows the potential to apply epidermal electronics to many challenging conditions.


Assuntos
Nanofibras , Suor , Artefatos , Eletrodos , Permeabilidade
12.
Soft Matter ; 17(40): 9057-9065, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34581395

RESUMO

Hydrogel-based soft and stretchable materials with skin/tissue-like mechanical properties provide new avenues for the design and fabrication of wearable sensors. However, synthesizing multifunctional hydrogels that simultaneously possess excellent mechanical, electrical and electromagnetic interference (EMI) shielding effectiveness is still a great challenge. In this work, the freeze-casting method is employed to fabricate a multifunctional hydrogel by filling Fe3O4 clusters into poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid) (PEDOT:PSS) and polyvinyl alcohol (PVA) composite aqueous solution. The hydrogel possesses superior electrical and mechanical properties as well as great electromagnetic wave shielding properties. Benefiting from the high stretchability (∼904.5%) and fast sensing performance (response time ∼9 ms and self-recovery time ∼12 ms within the strain range ∼100%), the monitoring of human activities and manipulation of a remote-controlled toy car using the hydrogel-based stretchable strain sensors are successfully demonstrated. In addition, a great EMI shielding effectiveness with more than 46 dB in the frequencies of 8-12.5 GHz can be obtained, which provides an alternative strategy for designing next-generation EMI shielding materials. These results indicate that the multifunctional hydrogels can be used as flexible and stretchable sensing electronics requiring effective EMI shielding.

13.
Angew Chem Int Ed Engl ; 59(52): 23800-23809, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-32945080

RESUMO

A 2D boron nanosheet that exhibits high theoretical capacitance, around four times that of graphene, is a significant supercapacitor electrode. However, its bulk structure with low interlaminar conduction and porosity restricts the charge transfer, ion diffusion, and energy density. Herein, we develop a new 2D hetero-nanosheet made of anisotropic boron-carbon nanosheets (ABCNs) by B-C chemical bonds via gas-phase exfoliation and condensation bottom-up strategy. The ABCNs are constructed into high flexible supercapacitor electrode by microfluidic electrospinning. The ABCN electrode greatly promotes smooth migration and excessive storage of electrolyte ions due to large interlayer conductivity, ionic pathways, and accessible surfaces. The flexible supercapacitor delivers ultrahigh volumetric energy density of 167.05 mWh cm-3 and capacitance of 534.5 F cm-3 . A wearable energy-sensor system is designed to stably monitor physiological signals.

14.
Adv Sci (Weinh) ; 7(14): 2000261, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32714750

RESUMO

The rapid progress of Internet of things (IoT) technology raises an imperative demand on human machine interfaces (HMIs) which provide a critical linkage between human and machines. Using a glove as an intuitive and low-cost HMI can expediently track the motions of human fingers, resulting in a straightforward communication media of human-machine interactions. When combining several triboelectric textile sensors and proper machine learning technique, it has great potential to realize complex gesture recognition with the minimalist-designed glove for the comprehensive control in both real and virtual space. However, humidity or sweat may negatively affect the triboelectric output as well as the textile itself. Hence, in this work, a facile carbon nanotubes/thermoplastic elastomer (CNTs/TPE) coating approach is investigated in detail to achieve superhydrophobicity of the triboelectric textile for performance improvement. With great energy harvesting and human motion sensing capabilities, the glove using the superhydrophobic textile realizes a low-cost and self-powered interface for gesture recognition. By leveraging machine learning technology, various gesture recognition tasks are done in real time by using gestures to achieve highly accurate virtual reality/augmented reality (VR/AR) controls including gun shooting, baseball pitching, and flower arrangement, with minimized effect from sweat during operation.

15.
Talanta ; 214: 120869, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32278417

RESUMO

Development of stretchable potentiometric ion sensors has the observable potential for wearable devices to continuously monitoring of electrolytes in body fluids. However, the mechanical mismatch between soft elastomeric substrate and ion-selective electrode components greatly hinders sensor's fabrication and its stretching stability for long-term use. Here, we propose a new strategy to construct a potentiometric ion sensor on a surface strain redistributed elastic fiber (SSRE-fiber) with both high stretchability and high sensing stability. The SSRE-fiber is designed with a unique unilateral bead structure, which significantly changes its surface strain distribution during deformation. Benefit from this platform, the active sensing materials with high Young's modulus fabricated on the unilateral bead region can keep unchanged during stretching (0-200%). Thus, the as-prepared potentiometric sensors (ion-selective electrode and polymer/inorganic salt membrane-coated reference electrode) can perform with stable functions ignoring the stretching of the fiber. This new SSRE-fiber platform paves a way for the design of highly stretchable and stable electrochemical sensor capable of integrating into textiles for wearable biochemical detection applications.

16.
Materials (Basel) ; 13(3)2020 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-31991923

RESUMO

Effects of different Y contents (0, 0.3, 0.7, 1.5, 3, 5 and 10 wt.%) on the microstructure, thermal stability and mechanical properties of Mg-3Zn-1Mn (ZM31) alloys were systematically studied. The existence form and action mechanism of Y in the experimental alloys were investigated. The results revealed that with the change of Y content, the main phases of the ZM31-xY alloys changed from Mg7Zn3 phase, I-phase, I + W-phase, W-phase, W + LPSO phase to LPSO phase. When Y content was low (≤1.5%), hot extrusion could break up the residual phases after homogenization to form dispersed fine rare-earth phase particles, and fine second phases would also precipitate in the grain, which could inhibit the grain growth. When Y content was high (≥3%), the experimental alloys were only suitable for high-temperature extrusion due to the formation of the high heat stable rare-earth LPSO phase. In addition, Y could evidently enhance the mechanical properties of the as-extruded ZM31 alloy, of which the ZM31-10Y alloy had the best mechanical properties, that is, the tensile and yield strengths are 403 MPa and 342 MPa. The high strengths of the alloys were mainly determined by fine grain strengthening, rare-earth phase strengthening and dispersion strengthening of fine α-Mn particles.

17.
Microsyst Nanoeng ; 6: 31, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34567645

RESUMO

Manufacture of large-scale patterned nanomaterials via top-down techniques, such as printing and slurry coating, have been used for fabrication of miniaturized gas sensors. However, the reproducibility and uniformity of the sensors in wafer-scale fabrication are still a challenge. In this work, a "top-down" and "bottom-up" combined strategy was proposed to manufacture wafer-scaled miniaturized gas sensors with high-throughput by in-situ growth of Ni(OH)2 nanowalls at specific locations. First, the micro-hotplate based sensor chips were fabricated on a two-inch (2") silicon wafer by micro-electro-mechanical-system (MEMS) fabrication techniques ("top-down" strategy). Then a template-guided controllable de-wetting method was used to assemble a porous thermoplastic elastomer (TPE) thin film with uniform micro-sized holes (relative standard deviation (RSD) of the size of micro-holes <3.5 %, n > 300), which serves as the patterned mask for in-situ growing Ni(OH)2 nanowalls at the micro-hole areas ("bottom-up" strategy). The obtained gas microsensors based on this strategy showed great reproducibility of electric properties (RSD < 0.8%, n = 8) and sensing response toward real-time H2S detection (RSD < 3.5%, n = 8).

18.
Microsyst Nanoeng ; 6: 84, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-34567694

RESUMO

The memristor has been regarded as a promising candidate for constructing a neuromorphic computing platform that is capable of confronting the bottleneck of the traditional von Neumann architecture. Here, inspired by the working mechanism of the G-protein-linked receptor of biological cells, a novel double-layer memristive device with reduced graphene oxide (rGO) nanosheets covered by chitosan (an ionic conductive polymer) as the channel material is constructed. The protons in chitosan and the functional groups in rGO nanosheets imitate the functions of the ligands and receptors of biological cells, respectively. Smooth changes in the response current depending on the historical applied voltages are observed, offering a promising pathway toward biorealistic synaptic emulation. The memristive behavior is mainly a result of the interaction between protons provided by chitosan and the defects and functional groups in the rGO nanosheets. The channel current is due to the hopping of protons through functional groups and is limited by the traps in the rGO nanosheets. The transition from short-term to long-term potentiation is achieved, and learning-forgetting behaviors of the memristor mimicking those of the human brain are demonstrated. Overall, the bioinspired memristor-type artificial synaptic device shows great potential in neuromorphic networks.

19.
Sensors (Basel) ; 19(21)2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31661821

RESUMO

Behavioral assessment, such as systematic scoring or biomechanical measurement, is often used to evaluate the extent of the damage and the degree of recovery after spinal cord injury. However, the use of these methods in standardized evaluation is limited because they are subjective and require complex test systems to implement. Here, we report a novel, flexible, microstructure-based pressure sensor and demonstrate its superior sensitivity (235.12 kPa-1 for 5.5~135 Pa and 2.24 kPa-1 for 0.6~25 kPa), good waterproofness, fast response and recovery times (response time: 8 ms, recovery time: 12 ms), stable response over 8000 loading/unloading cycles, and wide sensing range. These features readily allow the sensor to be comfortably attached to the hindlimbs of mice for full-range, real-time detection of their behavior, such as crawling and swimming, helping to realize quantitative evaluation of animal motor function recovery after spinal cord injury.


Assuntos
Eletrônica/métodos , Pressão , Traumatismos da Medula Espinal/fisiopatologia , Animais , Modelos Animais de Doenças , Eletrodos , Eletrônica/instrumentação , Extremidade Inferior/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Músculo Esquelético/fisiologia , Recuperação de Função Fisiológica , Natação
20.
Nano Lett ; 19(8): 5544-5552, 2019 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-31348665

RESUMO

Flexible self-powered multifunctional sensing systems provide a promising direction for the development of wearable electronics. Although increased efforts have been devoted to developing self-powered integrated devices, the development of flexible and adaptable sensing systems with miniaturized stable power supplies is highly desirable yet greatly challenging. Herein, an ambient moisture-induced self-powered wearable sensing system was fabricated by integrating a porous polydopamine layer with a hydroxy group gradient (called g-PDA) based moisture-enabled power generator and a flexible pressure sensor. Due to the large amount of gradient-distributed free cations (H+) and locally confined anions produced in wide electrode spaces during hydration of the thin porous g-PDA film, the moisture-induced potential and effective output power density of the g-PDA-based power generator rapidly reaches up to 0.52 V and 0.246 mW cm-2, respectively. Importantly, the voltage output within 120 s only has 6% change, and a continuously open-circuit voltage can be maintained after 1900 s of attenuation, which is a breakthrough for the duration of humidity generation. Finally, a self-powered wearable multifunctional sensing system has been demonstrated to be able to provide real-time monitoring of human physiological signals, without an external power supply, which opens new opportunities for future self-powered multifunctional sensing systems.


Assuntos
Fontes de Energia Elétrica , Dispositivos Eletrônicos Vestíveis , Eletrodos , Desenho de Equipamento , Humanos , Indóis/química , Polímeros/química , Pressão , Água/química
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