Search

Ammonia (NH

Indirectly monitoring Listeria monocytogenes (LMs) via gas sensor detecting metabolites 3-hydroxy-2-butanone (3H-2B) biomarker is a newly-emerged strategy. However, such sensors are required to simultaneously endow with outstanding selectivity, high sensitivity and ppb-level detection limit, which remains technologically challenging. Herein, we have developed highly selective and sensitive 3H-2B sensors with zinc oxide nanorods decorated with cobaltosic oxide nanoparticles (ZnO NRs / Co3O4 NPs), which have been synthesized by an optimized hydrothermal and annealing process. Specifically, the ZnO NRs / Co3O4 NPs exhibit ultrahigh sensitivity toward 5 ppm 3H-2B (Ra / Rg = 550 at 260 oC). Meanwhile, the sensor prototypes enable to detect as low as 10 ppb 3H-2B, show excellent long-term stability, and present remarkable selectivity through interfering selectivity survey and principal component analysis (PCA). Such outstanding sensing performance is attributed to the the modulated electron depletion layer by n / p heterojunction and abundant gas diffusion pathways of radial architectures, which is testified via electrochemical impedance spectroscopy test, Mott-Schottky measurement and ultraviolet-visible absorption analysis. Our highly selective and sensitive ZnO NRs / Co3O4 NPs are potential in real-time detection of 3H-2B biomarker of LMs.

Nobiletin was found to mitigate nonalcoholic fatty liver disease by enhancing TFEB-mediated lipophagy, alleviating NLRP3 inflammasome and modulating macrophages polarization.

Nonalcoholic fatty liver disease (NAFLD), an increasingly serious health issue around the world, is characterized as a lipid metabolic disorder without any satisfactory treatment. Nobiletin (NOB), a citrus flavonoid, is considered a promising candidate for NAFLD prevention although there is limited research towards its exact mechanism. In this study, the preventative effect of NOB on NAFLD was investigated using high fat diet-fed ApoE

Indirectly monitoring halitosis via the detection of hydrogen sulfide (H2S) biomarkers using gas sensors is a newly emerging technique. However, such H2S sensors are required with critically high selectivity and sensitivity, as well as a ppb-level detection limit, which remains technologically challenging. To address such issues, here, we have developed highly sensitive and selective H2S sensors with NiO/WO3 nanoparticles (NPs), which have been synthesized by firstly hydrolyzing WO3 NPs and subsequently decorating with NiO NPs in a hydrothermal process. Theoretically, the NiO/WO3 NPs assist in forming a thicker electron depletion layer, adsorbing more oxygen species O2- to oxidize H2S and finally release more electrons. Beneficially, 2.1 wt % NiO/WO3 NPs show high sensitivity to H2S (Ra/Rg = 15031 ± 1370 @ 10 ppm, 100 °C), which is 42.6-fold higher than that of the pristine WO3 NPs (Ra/Rg = 353 ± 5.6 @ 10 ppm, 100 °C). Further, the H2S sensor shows ppb-level detection limit (Ra/Rg = 4.95 ± 2.9 @ 0.05 ppm, 100 °C) and high selectivity. Practically, NiO/WO3 NP sensor prototype has been employed to detect the simulated exhaled halitosis compared with that of gas chromatography, revealing a close concentration of H2S. Our investigation offers an experimental base in future intelligent medical applications.

This paper presents a deep reinforcement learning (DRL)-based three-dimensional path tracking control algorithm of an underwater robot to learn the path-tracking capability by interacting with the environment. To be specific, a hybrid path tracking guidance and controller based on three-dimensional line-of-sight (3D LOS) guidance and twin delayed deep deterministic policy gradient (TD3) algorithm is applied to complete kinematics and dynamics controller design. The reference angle is obtained by LOS algorithm, and TD3 algorithm is used to output the control laws. Aiming at the chattering problem in the output of the reinforcement learning controller, the commands filter and chattering penalty term are designed respectively. The tracking experiment of ten waypoints proves the feasibility of the algorithm proposed in this paper.

Gas sensors built with metal oxide semiconductors have attracted tremendous attention due to the growing demand for the detection of inflammable, explosive and toxic gases. Herein, to improve the sensing response, WO3 nanoparticles decorated with Ag and Pt bimetals (Ag and Pt/WO3 NPs) have been developed via combined hydrolysis and hydrothermal strategies. Such sensors prototypes show high response to acetone (Ra/Rg = 250 @ 100 × 10–6, 140 °C), which is 6.1 fold as high as that of the pristine WO3 NPs (Ra/Rg = 41 @ 100 × 10–6, 140 °C). Moreover, the recovery time of Ag and Pt/WO3 NPs was reduced from 138 to 13 s compared with that of the pristine WO3 NPs. The improved acetone sensing performance may be attributed to that the chemical and electronic sensitization of Ag and Pt to WO3 NPs increases adsorbed oxygen species, speeds up the reaction and thus boosts the sensing response. Our strategy that decoration of dual precious metals onto WO3 NPs improves the acetone sensing performance may be applied to the gas sensors of other sensing materials.

Hydrogen sensing simultaneously endowed with fast response, high sensitivity and selectivity is highly desired in detecting hydrogen leakages such as in hydrogen-driven vehicles and space rockets. Here, hydrogen sensing reined via a hydrogen spillover effect has been developed using palladium nanoparticles photochemically decorated on WO3 nanoparticles (Pd-NPs@WO3-NPs). Theoretically, the Pd-NP catalysts and WO3-NP support are used to construct the hydrogen spillover system, in which Pd NPs possess high catalytic activity, promoting the electron transfer and therefore the reaction kinetics. Beneficially, the Pd-NPs@WO3-NP sensor prototypes toward 500 ppm hydrogen simultaneously exhibit fast response time (∼1.2 s), high response (Ra/Rg = 22 867) and selectivity at a working temperature of 50 °C. Such advanced hydrogen sensing provides an experimental basis for the smart detection of hydrogen leakage in the future hydrogen economy.

Hydrogen (H

The newly-emerged breath sensing detection of disease biomarkers (e.g., H2S and acetone) offers rapid and noninvasive early diagnosis of diseases (e.g., halitosis and diabetes). Utilizing a single sensor to monitor dual biomarkers may contribute to both miniaturized size and multi-detection if implemented, but remains challenging. Here, interconnected BiFeO3/Bi25FeO40 nanoparticles (NPs, ∼22.5 nm in diameter) synthesized via combined microwave hydrothermal and annealing methods have been developed to selectively detect dual biomarkers of halitosis and diabetes. The selective detection has been modulated by an n/p semiconducting transformation, and has been experimentally observed and theoretically interpreted, in which electron–hole pairs are modulated due to the synergistic effect of temperature-dependent adsorbed oxygen molecules and semiconducting band bending. Remarkably, the sensor prototypes enable the selective detection of both H2S (n-type mode) and acetone (p-type mode) biomarkers with superior stability and a ppb-level detection limit. Furthermore, practical human breath has been experimentally simulated. Critically, the sensors with a waterproof membrane have been tested by immersing them into water. Our strategy of the detection of dual exhaled biomarkers by a single gas sensor may contribute to the integration and miniaturization of sensors, for upcoming intelligent medical treatment.

Indirect monitoring of

Hydrogen sensing simultaneously endowed with fast response, high sensitivity and selectivity is highly desired in detecting hydrogen leakages such as in hydrogen-driven vehicles and space rockets. Here, hydrogen sensing reined via a hydrogen spillover effect has been developed using palladium nanoparticles photochemically decorated on WO

The stability for a hydrogen sensor is of crucial importance under a low-temperature range (e.g., 200-400 K), especially in critical environments (e.g., aerospace). However, the "reverse sensing behavior" of Pd-based sensing materials at low temperatures limits their wide application. Herein, a three-dimensional (3D) hydrogen-sensing material of interconnected Pd nanoparticles supported on zeolite-AFI (zeolite-AFI@Pd NPs) is designed for the hydrogen sensor at low temperature. The interconnected Pd NPs of ∼15 nm in diameter are achieved onto the zeolite-AFI framework by reduction-controlled self-assembly growth, followed by partially etching-off zeolite. The 3D structure provides a larger surface ratio for improving hydrogen adsorption onto Pd, and more space for PdHx intermediate expansion, which effectively facilitates response to hydrogen and suppresses the α-β phase transition. Remarkably, there is no "reverse sensing behavior" observed in zeolite-AFI@Pd NPs, though temperature is as low as to 200 K compared with that of pristine Pd nanowires at 287 K. Furthermore, the zeolite-AFI@Pd NPs sensors yield excellent sensing response and high stability to hydrogen at temperature from 200 to 400 K. Such Zeolite-AFI@Pd NPs sensors are expected to detect hydrogen leakage, especially in critical environments of low temperature.

In this study, hematite (α-Fe2O3) micro-spheres coated with ultrafine particles (MSUPs) have been obtained for sensitive acetone sensors via first hydrothermal process with NH4F as the morphological regulator and then annealing of akaganeite. The role of fluoride ion concentration in precursor solution on the morphology has been demonstrated, and the corresponding reaction mechanism was discussed as well. The α-Fe2O3 MSUPs with 0.45 M NH4F (F0.5) in the precursor solution showed the highest response towards acetone compared to other α-Fe2O3 samples. Our α-Fe2O3 MSUPs sensors have potential in sensitive acetone detection.

Listeria monocytogenes (LMs) that release 3-hydroxy-2-butanone (3H-2B) biomarker, can cause serious human illness and even death; in this regard, conventional techniques for the smart detection of LMs are of vital importance; however, they still suffer from the requirement of either sophisticated techniques or complicated instrumentation. Herein, we report a metal-oxide semiconductor (MOS) sensor, built with 3D mesoporous nickel oxide nanocuboids (M-NiO NCs), for the detection of LMs. The M-NiO NCs were obtained by directly sacrificing nickel foam in oxalic acid, followed by subsequent annealing. The M-NiO NCs have a rough surface and many multichannel pathways. Impressively, gas sensors built with M-NiO NCs display excellent sensing performance towards the 3H-2B biomarker, exhibiting an ultrahigh sensitivity (Rg/Ra = 302 at 50 ppm) and excellent selectivity. Moreover, the 3H-2B sensor presents excellent long-term stability and, particularly, a low limit of detection (LOD = 0.5 ppm) at 120 °C. The multichannel pathways of the M-NiO NCs contribute to gas adsorption and diffusion, thus enhancing the sensing behavior. Our study provides an ingenious and low-cost strategy to produce mesoporous NiO nanostructures as well as new insights for the detection of pathogenic microbes in food.

The metallic dopants in palladium (Pd) sensing materials enable modification of the d-band center of Pd, which is expected to tune the α–β phase transitions of the PdHx intermediate, thus improve the sensing stability to hydrogen. Here, the boosted hydrogen-sensing stability at ultra-low temperatures has been achieved with palladium/cobalt nanowires (PdCo NWs) as the sensing material. The various Co contents in PdCo NWs were modulated via AAO-template-confined electrodeposition. The temperature-dependent sensing evaluations were performed in 0.1–3 v/v% hydrogen. Such sensors integrated with PdCo NWs are able to stably detect hydrogen as low as 0.1 v/v%, even when the temperature is lowered to 273 K. In addition, the critical temperatures of “reverse sensing behavior” of the PdCo NWs (Pd82Co18: Tc = 194 K; Pd63Co37: Tc = 180 K; Pd33Co67: Tc = 184 K) are observed much lower than that of pristine Pd NWs (Tc = 287 K). Specifically, the Pd63Co37 NWs (∼37 at% Co content) sensor shows outstanding stability of sensing hydrogen against α–β phase transitions within the wide temperature range of 180–388 K, which is attributed to both the electronic interactions between Pd and Co and the lattice compression strain caused by Co dopants. Moreover, the “reverse sensing behavior” of the PdCo NWs is explicitly interpreted using the α–β phase transition model.

An ideal way to boost the selectivity of sensing materials is that improving the sensitivity of the target gas while suppressing that of other interfering ones. Here, the "screening behavior" of the Li doped WO

Indirectly monitoring halitosis via the detection of hydrogen sulfide (H

Gaseous ammonia (NH3) under high concentration (e.g., larger than 25 ppm) is usually harmful to human organs. Instead, lower - concentration NH3 that is generated from human metabolism may serve as a biomarker for exhaled diagnosis of kidney disease. Ideally, wearable NH3 sensors integrated over cloths are highly desired for real-time monitoring. Here, twistable and tailorable nanocomposites (NCPs) textile has been developed for yielding wearable NH3 sensing, by which graphene oxide was firstly mixed with aniline monomer, and subsequently this mixture was in-situ polymerized by vanadium pentoxide to obtain a ternary NCPs of vanadium oxide, polyaniline and graphene oxide (V2O5/PANI/GO NCPs). Benefiting from the incorporation of PANI, V2O5 and GO, the V2O5/PANI/GO NCPs textile shows enhanced response (Rg/Ra −1 = 31.2 ± 1.8% @10 ppm NH3, room temperature), high stability that maintains 91.5% response after 56 days and excellent interfering selectivity. Remarkably, the V2O5/PANI/GO NCPs textile displays excellent twistability and tailorability. This strategy to V2O5/PANI/GO NCPs textile might be extended to nanosensing materials that could be integrated onto other textiles.

We report zinc oxide (core) coated with alumina (shell) single-shelled nanocables (ZnO@Al2O3 NCBs) for detection of 3-hydroxy-2-butanone (3H-2B) biomarker, which was prepared via aluminum-anodic-oxide (AAO) template confined electrodeposition, chemical etching and leaving thin AAO-channel wall with broken surface. In the core/shell nanostructure, the outer Al2O3 layer protects ZnO from interference gases, while the pores allow the target gas to react with the oxygen specie on the surface of ZnO. For as-built ZnO@Al2O3 NCBs sensors, the detection limit is as low as 1 ppm, and the response value to 50 ppm 3H-2B is 37.2 at 300 °C. Moreover, the ZnO@Al2O3 NCBs show excellent selectivity and cyclic stability. Our ZnO@Al2O3 NCBs sensors in future monitoring Listeria monocytogenes.

An ideal way to boost the selectivity of sensing materials is that improving the sensitivity of the target gas while suppressing that of other interfering ones. Here, the “screening behavior” of the Li doped WO3 nanofibers (Li/WO3 NFs) have been discovered in suppressing the response from interfering gases, while elevating the H2S sensing response. Beneficially, the H2S response of Li/WO3 NFs sensor prototype is three times (Ra / Rg = 64@10 ppm) as high as that of the pristine WO3 ones (Ra / Rg = 21@10 ppm) at ~75% relative humidity and 260 °C. Moreover, Li/WO3 NFs sensor prototype presents the detection limit as low as 100 ppb. Particularly, the Li/WO3 NFs sensors detect simulated halitosis breath, of which the accuracy is comparable with gas chromatography. Theoretically, the decrease of the responses of Li/WO3 NFs to interfering gases is ascribed to the enhancement of the adsorption of water molecules by Li dopant. While the improved response to H2S is attributed to stronger adsorption of H2S and WO3 and to the increased defect oxygen. The “screening behavior” of Li doped into WO3 NFs provides a new strategy that might improve the selectivity of other gas sensing.

Ski is an evolutionarily conserved protein and widely participates in the regulation of various pathological and physiological processes such as wound healing, liver regeneration, development of the embryonic nervous system, muscle differentiation, and progression of many kinds of tumors. However, the distribution and function of Ski in central nervous system lesion and disease remain unclear. In this study, we investigated the spatiotemporal expression of Ski in a spinal cord injury (SCI) model in adult rats. Western Blot analysis indicated that Ski was expressed in both normal and injured spinal cord, and showed a significant upregulation after SCI compared with the sham group. Double-labeled immunofluorescence staining showed that Ski was significantly expressed in astrocytes, but not in the neurons. Western Blot analyses of glial fibrillary acidic protein (GFAP) and BBB scores were carried out and correlation analysis showed a positive correlation between them. In addition, the relative expression level of Ski was also positively correlated with the relative expression level of GFAP. Moreover, the conspicuous co-expression band of Ski and GFAP at the lesion border was found in the results of immunofluorescence staining combined with the pattern of glial scar formation reflected by HE staining; in addition, it was found that Ski was also highly associated with glial scar. On the basis of our data, we speculated that Ski might play an important role in the process of reactive astrogliosis after SCI and our study might provide a basis for further study on the detailed role of Ski in astrocytes.

As a high-energy-density, renewable and green energy carrier, hydrogen has recently received increasing attention. However, the reliable detection for hydrogen leakage, especially in harsh environmental conditions, and the efficient high-purity hydrogen production are still challenging issues. Here, we report that uniform palladium-nickel nanowires (PdNi NWs) arrays, which have been synthesized via anode-aluminum-oxide (AAO) template-confined electrodeposition as bi-functional material for hydrogen leakage detection and hydrogen evolution reaction (HER). PdNi NWs arrays exhibit rough surface with the diameter of ~60 nm and present alloyed crystallization. Benefited from the synergic effect of the rough surface of PdNi NWs etched during synthesis and the electronic structure of Pd modified by Ni, PdNi NWs enable to stably work within the wide temperature range of 153–388 K, in which the Pd-Ni alloying decreases the critical temperature of “reverse sensing behavior” to 153 K. Meanwhile, the PdNi NWs show the overpotential of 91 mV at 10 mA/cm2, and the Tafel slope of 96 mV/dec in 0.5 M H2SO4. The PdNi NWs show great potential in both hydrogen leakage detection and hydrogen evolution reaction.

The newly emerged gas sensing detection of 3-hydroxy-2-butanone (3H-2B) biomarker is deemed as an effective avenue to indirectly monitor Listeria monocytogenes (LM). However, 3H-2B sensing materials requiring critically high sensitivity and selectivity, and ppb-level detection limit, remain challenging. Here, we report the advanced gas sensors built with bismuth vanadate microdecahedron (BiVO4 MDCD) {010} facets selectively decorated with Pd nanoparticles (Pd NPs, Pd-{010}BiVO4 MDCDs) for boosted detection of the 3H-2B biomarker. Meanwhile, BiVO4 MDCDs with overall facets are randomly deposited with Pd NPs (Pd-BiVO4 MDCDs). Comparatively, Pd-{010}BiVO4 MDCD sensors show 1 order of magnitude higher response toward the 3H-2B biomarker at 200 °C. Further, Pd-{010}BiVO4 MDCD sensors enable to detect as low as 0.2 ppm 3H-2B and show best selectivity and stability, and fastest response and recovery. Density functional theory calculations reveal a lower adsorption energy of 3H-2B onto Pd-{010}BiVO4 MDCDs than those of pristine and Pd-BiVO4 MDCDs. The extraordinary Pd-{010}BiVO4 sensing performance is ascribed to the Pd NP-assisted synergetic effect of the preferential adsorption of 3H-2B target molecules, accumulated sensing agent of ionic oxygen species, and concentrated catalysts on the {010} facets. This strategy offers rapid and noninvasive detection of LMs and is thus of great potential in the upcoming Internet of Things.

Detection of 3-hydroxy-2-butanone (3H-2B) biomarker is a newly emerging and feasible way to monitor Listeria monocytogenes (LMs). Although progress has been made in gas-sensing methodology, the long-term adsorption of the reactive products onto the sensing materials leads to a decrease in stability and selectivity. Herein, we report highly selective and stable 3H-2B sensors, which are developed from a core / shell structure of tin oxide nanowire coated with alumina (SnO2@Al2O3 NCBs), via combining AAO template-confined electrodeposition and wet-chemical etching. As-built sensors exhibit high sensitivity of Ra/Rg = 43.3 to 5 ppm 3H-2B at 120 °C, which is around 6–40 times against other interfering gases. Also, our sensors exhibit excellent stability after 42 days′ evaluation. Furthermore, the sensors can detect as low as 0.1 ppm 3H-2B (Ra/Rg = 2.4; 120 °C), and the sensitivity reach Ra/Rg = 27.2 at 50 °C. Our SnO2@Al2O3 NCBs sensors are endowed with ppb-level detection limit, excellent selectivity and stability at low temperature, which is of great potential in future detection of LMs.

Spinal cord ischemia and reperfusion (SCIR) injury can lead to neurologic dysfunction and paraplegia, which are serious complications after shock or thoracoabdominal aortic surgery. Autophagy is a fundamental cellular process in eukaryotes, and homeostasis of autophagic activities in the cytoplasm is critical for the maintenance of neuronal function. To date, no studies have addressed the involvement of autophagy in the regulation of motor neurons in the ventral horn of the spinal cord area following SCIR-induced spastic paralysis or the underlying mechanisms of this process. In this study, we investigated spastic paralysis in rats following SCIR injury. The number of autophagosomes increased 3 h following the injury, and subsequently decreased slowly to near-normal levels in the sham group as indicated by the autophagy markers microtubule-associated protein 1 light chain 3 (LC3), beclin-1, and p62. Furthermore, after treatment with the autophagy inhibitor 3-Methyladenine (3-MA) and autophagy activator rapamycin following SCIR, autophagy in the SCIR-3-MA group decreased significantly, while that in the SCIR-Rap group increased, compared with SCIR-DMSO controls group. Moreover, the assessment of motor neurons function, using Reuter’s score and motor evoked potentials (MEP) and somatosensory evoked potentials (SEP), indicated that promoting autophagy reduced scores compared with SCIR controls, while inhibiting autophagy increased the scores, and hence motor neurons function. Autophagy in the SCIR model protected motor neurons function and morphology. These results would provide more evidences for better understanding function of autophagy in motor neurons degeneration and mechanisms underlying spastic paralysis. Autophagy would be a novel target for prevention and therapy in SCIR damage.