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1.
Nano Lett ; 24(35): 10883-10891, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39172995

RESUMEN

The development of electronic skin (e-skin) emulating the human skin's three essential functions (perception, protection, and thermoregulation) has great potential for human-machine interfaces and intelligent robotics. However, existing studies mainly focus on perception. This study presents a novel, eco-friendly, mechanically robust e-skin replicating human skin's three essential functions. The e-skin is composed of Ti3C2Tx MXene, polypyrrole, and bacterial cellulose nanofibers, where the MXene nanoflakes form the matrix, the bacterial cellulose nanofibers act as the filler, and the polypyrrole serves as a conductive "cross-linker". This design allows customization of the electrical conductivity, microarchitecture, and mechanical properties, integrating sensing (perception), EMI shielding (protection), and thermal management (thermoregulation). The optimal e-skin can effectively sense various motions (including minuscule artery pulses), achieve an EMI shielding efficiency of 63.32 dB at 78 µm thickness, and regulate temperature up to 129 °C in 30 s at 2.4 V, demonstrating its potential for smart robotics in complex scenarios.


Asunto(s)
Conductividad Eléctrica , Polímeros , Dispositivos Electrónicos Vestibles , Humanos , Polímeros/química , Pirroles/química , Nanofibras/química , Celulosa/química , Piel/química , Regulación de la Temperatura Corporal , Titanio/química , Robótica
2.
Small ; : e2404822, 2024 Aug 03.
Artículo en Inglés | MEDLINE | ID: mdl-39096107

RESUMEN

Selective photocatalytic CO2 reduction to high-value hydrocarbons using graphitic carbon nitride (g-C3N4) polymer holds great practical significance. Herein, the cyano-functionalized g-C3N4 (CN-g-C3N4) with a high local electron density site is successfully constructed for selective CO2 photoreduction to CH4 and C2H4. Wherein the potent electron-withdrawing cyano group induces a giant internal electric field in CN-g-C3N4, significantly boosting the directional migration of photogenerated electrons and concentrating them nearby. Thereby, a high local electron density site around its cyano group is created. Moreover, this structure can also effectively promote the adsorption and activation of CO2 while firmly anchoring *CO intermediates, facilitating their subsequent hydrogenation and coupling reactions. Consequently, using H2O as a reducing agent, CN-g-C3N4 achieves efficient and selective photocatalytic CO2 reduction to CH4 and C2H4 activity, with maximum rates of 6.64 and 1.35 µmol g-1 h-1, respectively, 69.3 and 53.8 times higher than bulk g-C3N4 and g-C3N4 nanosheets. In short, this work illustrates the importance of constructing a reduction site with high local electron density for efficient and selective CO2 photoreduction to hydrocarbons.

3.
Phys Chem Chem Phys ; 26(28): 19564-19572, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-38980004

RESUMEN

As an emerging two-dimensional material, MXene has shown a wide range of applications, which has triggered the demand for efficient exfoliation of nanoflakes with large size and specific surface area. Here, we took advantage of the efficient photo-thermal conversion of Ti3C2Tx and employed 532 nm continuous wave laser irradiation to assist the traditional ultrasonic exfoliation, with no need for complex equipment and an expensive femtosecond or picosecond laser. This approach greatly improves the exfoliation efficiency, increases the size, uniformity and specific surface area of the Ti3C2Tx nanoflakes, and reduces energy consumption as well. The electrical conductivity of Ti3C2Tx film is also significantly enhanced (from 3135 to 7433 S m-1). It is demonstrated that the laser promotes the formation of Ti-OH and enhances the solubility of Ti3C2Tx in water, facilitating the exfoliation and preventing oxidation as a result.

4.
J Insect Sci ; 152015.
Artículo en Inglés | MEDLINE | ID: mdl-26163666

RESUMEN

Autophagy is associated with multiple biological processes and has protective and defensive functions with respect to immunity, inflammation, and resistance to microbial infection. In this experiment, we wished to investigate whether autophagy is a factor in the midgut cell response of Bombyx mori to infection by the B. mori cytoplasmic polyhedrosis virus (BmCPV). Our results indicated that the expression of three autophagy-related genes (BmAtg8, BmAtg5, and BmAtg7) in the midgut did not change greatly after BmCPV infection in B. mori. Basal ATG8/ATG8PE protein expression was detected in different B. mori tissues by using western blot analysis. Immunohistochemistry showed that the ATG8/ATG8PE proteins were located mainly in the cytoplasm. ATG8/ATG8PE protein levels decreased at 12 and 16 h after BmCPV infection. Our results indicate that autophagy responded slightly to BmCPV infection, but could not prevent the invasion and replication of the virus.


Asunto(s)
Autofagia , Bombyx/fisiología , Bombyx/virología , Regulación de la Expresión Génica , Reoviridae/fisiología , Animales , Bombyx/genética , Sistema Digestivo/virología , Fenómenos Fisiológicos del Sistema Digestivo
5.
Nat Commun ; 15(1): 6138, 2024 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-39033166

RESUMEN

Integration of functional fillers into liquid metals (LM) induces rheology modification, enabling the free-form shaping of LM at the micrometer scale. However, integrating non-chemically modified low-dimensional materials with LM to form stable and uniform dispersions remain a great challenge. Herein, we propose a solvent-assisted dispersion (SAD) method that utilizes the fragmentation and reintegration of LM in volatile solvents to engulf and disperse fillers. This method successfully integrates MXene uniformly into LM, achieving better internal connectivity than the conventional dry powder mixing (DPM) method. Consequently, the MXene/LM (MLM) coating exhibits high electromagnetic interference (EMI) shielding performance (105 dB at 20 µm, which is 1.6 times that of coatings prepared by DPM). Moreover, the rheological characteristic of MLM render it malleable and facilitates direct printing and adaptation to diverse structures. This study offers a convenient method for assembling LM with low-dimensional materials, paving the way for the development of multifunctional soft devices.

6.
ACS Appl Mater Interfaces ; 15(37): 44205-44211, 2023 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-37672356

RESUMEN

Liquid crystal elastomers (LCEs) have been optimized by combining cross-linkers and dynamic bonds to achieve a reversible actuation behavior comparable to living skeletal muscles. In this study, one unique type of segment with 2-fold dynamic properties was introduced into LCEs, which offered not only dynamic diselenide covalent bonds for thermo-/photoplasticity but also H-bond arrays for dynamic cross-linking and mechanical robustness. Besides self-healing, self-welding, and recyclability, the LCEs were reprogrammable with elevated temperature or intensive visible light irradiation. The resultant LCEs gave an actuation blocking stress of 1.96 MPa and an elastic modulus of 14.4 MPa at 80 °C. The actuation work capacity reached 135.2 kJ m-3. When incorporating the Joule electrode or photothermal materials, the LCEs could be programmed as the electricity-driven and photothermal artificial muscles and thereby promised the application both as a biomimetic artificial hand and as an energy collector from sunlight. Thus, the 2-fold dynamic LCEs offered the pathway of enabling the reversible actuation behavior comparable to living skeletal muscles and promising applications in sustainable actuators, artificial muscles, and soft robots.


Asunto(s)
Cristales Líquidos , Músculo Esquelético , Biomimética , Módulo de Elasticidad , Elastómeros
7.
Mitochondrial DNA B Resour ; 7(8): 1548-1549, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36081829

RESUMEN

Clematoclethra scandens subsp. actinidioides (Actinidiaceae) is an endemic medicinal species in China. Here, we first sequenced and characterized the complete chloroplast genome of C. scandens subsp. actinidioides. The chloroplast genome was 159,341 bp in length, containing a large single-copy of 88,351 bp and a small single-copy of 21,580 bp separated by a pair of identical inverted repeat regions of 24,705 bp each. A total of 131 genes were identified, including 84 protein-coding genes, 39 tRNA, and eight rRNA genes. The phylogenetic analysis of C. scandens subsp. actinidioides showed a relatively close relationship with Clematoclethra scandens subsp. hemsleyi.

8.
J Phys Chem Lett ; 13(7): 1636-1643, 2022 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-35143214

RESUMEN

In this work, a hybrid structure of multilayer transition-metal dichalcogenides (TMDs) and a ferroelectric polymer is designed to achieve passive control of optical properties in situ. The electrical polarization in the ferroelectric poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) polymer can regulate the photoluminescence (PL) in bilayer WSe2. The total PL emission intensity is substantially suppressed or enhanced under large gate voltage in bilayer WSe2. This is because electrons transfer between the conduction band K valley and the conduction band Λ valley by the electrostatic field in the P(VDF-TrFE) polymer. This electron transfer further adjusts the proportion of direct and indirect excitons and, in turn, changes the overall optical radiation efficiency. We also illustrate that the engineered PL originates from the external electric-field-dependent transferred electron effect. The theoretical result matches the experimental data well. This work demonstrates a device platform in which passive regulation is achieved using 2D TMDs modulated by polarized ferroelectric materials.

9.
Mater Horiz ; 9(10): 2603-2612, 2022 10 03.
Artículo en Inglés | MEDLINE | ID: mdl-35942798

RESUMEN

Braille recognition is of great significance for the visually impaired and blind people to achieve convenient communication and learning. A self-powered Braille recognition sensing system with long-term survivability and phonic function could provide those people with greatly enhanced access to information and thus improve their living quality. Herein, we develop a skin-like self-powered Braille recognition sensor with self-healing, temperature-resistant and stretchable properties, which is further connected with the designed audio system to realize real-time conversion from mechanical stimulus to electrical signals and then to audio signals. The sensor is fabricated using dynamic interaction-based self-healing materials, which constitute an imine bond-based cross-linked polymer for the triboelectric layer and a hydrogen bond-based organohydrogel for the electrode layer. Moreover, the conductive organohydrogel-based electrode is provided with stretchable, anti-freezing, and non-drying properties. Consequently, minimized impact on the output performance of the sensor is found under mechanical impact, harsh environments and large deformation, enabling a long lifespan, high durability, and good stability. The self-powered sensor can be applied in a Braille recognition system, in which the Braille characters can be further decoded and read out. This work shows a reliable and flexible device with promising prospects in information technology.


Asunto(s)
Personas con Daño Visual , Electrodos , Humanos , Iminas , Polímeros , Temperatura
10.
Mitochondrial DNA B Resour ; 6(2): 413-414, 2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33659696

RESUMEN

The complete chloroplast (cp) genome sequence of Actinidia arguta var. giraldii (Diels) Vorosch. was assembled and characterized by Illumina pair-end sequencing date. The complete plastid genome was 156,729 bp in length, containing a large single-copy (LSC) of 89,647 bp, and a small single-copy (SSC) of 22,482 bp, which was separated by a pair of 22,300 bp inverted repeat regions (IR). A total of 131 unique genes were identified, including 84 protein-coding genes, 39 tRNA genes, and 8 rRNA genes. The phylogenetic position based on the chloroplast genome of 11 species showed that A. arguta var. giraldii was sister to Actinidia kolomikta.

11.
IEEE Trans Image Process ; 27(6): 2731-2746, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29553926

RESUMEN

The implementation of automatic image registration is still difficult in various applications. In this paper, an automatic image registration approach through line-support region segmentation and geometrical outlier removal is proposed. This new approach is designed to address the problems associated with the registration of images with affine deformations and inconsistent content, such as remote sensing images with different spectral content or noise interference, or map images with inconsistent annotations. To begin with, line-support regions, namely a straight region whose points share roughly the same image gradient angle, are extracted to address the issues of inconsistent content existing in images. To alleviate the incompleteness of line segments, an iterative strategy with multi-resolution is employed to preserve global structures that are masked at full resolution by image details or noise. Then, geometrical outlier removal is developed to provide reliable feature point matching, which is based on affine-invariant geometrical classifications for corresponding matches initialized by scale invariant feature transform. The candidate outliers are selected by comparing the disparity of accumulated classifications among all matches, instead of conventional methods which only rely on local geometrical relations. Various image sets have been considered in this paper for the evaluation of the proposed approach, including aerial images with simulated affine deformations, remote sensing optical and synthetic aperture radar images taken at different situations (multispectral, multisensor, and multitemporal), and map images with inconsistent annotations. Experimental results demonstrate the superior performance of the proposed method over the existing approaches for the whole data set.

12.
Genome Announc ; 3(1)2015 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-25657267

RESUMEN

Listeria monocytogenes is a facultative intracellular foodborne pathogen that can cause listeriosis in humans and animals. L. monocytogenes LM201 was isolated from foodstuff. The draft genome sequence of strain LM201 provides the genetic basis for the application of this strain in biotechnological vaccine production.

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