Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 21
Filtrar
1.
ACS Appl Mater Interfaces ; 16(15): 18608-18626, 2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38565551

RESUMO

Hypoxia, chronic inflammation, and elevated reactive oxygen species (ROS) production induced by hyperglycemia pose formidable challenges to the healing of diabetic chronic wounds, often resulting in impaired recovery. Currently, sustainable and eco-friendly therapeutic approaches targeting this multifaceted problem remain uncharted. Herein, we develop a unique three-functional covalent organic framework (COF)-modified microalgae gel designed for the preparation and treatment of chronic diabetic wounds. The gel comprises an oxygen-releasing basic fibroblast growth factor (bFGF) microalgae matrix, augmented by an ROS-responsive COF. Although two of these components have been reported to be used in wound healing, the combination of all three functions represents an innovative approach to synergize the treatment of chronic diabetic wounds. Therefore, we propose a new concept of "ligand interlocking" with three functional synergistic effects. Specifically, the COF has a similar effect to the "double Excalibur", which binds bFGF to promote angiogenesis and proliferation and inhibit the inflammatory response of chronic wounds and binds live microalgae to eliminate ROS and release dissolved oxygen to alleviate the hypoxia of wounds. Moreover, in vivo experiments and RNA sequencing analyses similarly demonstrated that the COF-modified microalgae gel reduced the inflammatory cascade cycle in the wound site and promoted vascular and tissue regeneration. We posit that the COF-modified microalgae gel represents a promising strategy for the active in vivo delivery of therapeutics to the wound body in intensive care unit settings.


Assuntos
Diabetes Mellitus , Estruturas Metalorgânicas , Microalgas , Humanos , Fator 2 de Crescimento de Fibroblastos , Espécies Reativas de Oxigênio , Géis , Hipóxia , Oxigênio , Hidrogéis
2.
J Ethnopharmacol ; 330: 118205, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-38641079

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng is a valuable herb in traditional Chinese medicine. Modern research has shown that it has various benefits, including tonifying vital energy, nourishing and strengthening the body, calming the mind, improving cognitive function, regulating fluids, and returning blood pressure, etc. Rg1 is a primary active component of ginseng. It protects hippocampal neurons, improves synaptic plasticity, enhances cognitive function, and boosts immunity. Furthermore, it exhibits anti-aging and anti-fatigue properties and holds great potential for preventing and managing neurodegenerative diseases (NDDs). AIM OF THE STUDY: The objective of this study was to examine the role of Rg1 in treating chronic inflammatory NDDs and its molecular mechanisms. MATERIALS AND METHODS: In vivo, we investigated the protective effects of Rg1 against chronic neuroinflammation and cognitive deficits in mice induced by 200 µg/kg lipopolysaccharide (LPS) for 21 days using behavioral tests, pathological sections, Western blot, qPCR and immunostaining. In vitro experiments involved the stimulation of HT22 cells with 10 µg/ml of LPS, verification of the therapeutic effect of Rg1, and elucidation of its potential mechanism of action using H2DCFDA staining, BODIPY™ 581/591 C11, JC-1 staining, Western blot, and immunostaining. RESULTS: Firstly, it was found that Rg1 significantly improved chronic LPS-induced behavioral and cognitive dysfunction in mice. Further studies showed that Rg1 significantly attenuated LPS-induced neuronal damage by reducing levels of IL-6, IL-1ß and ROS, and inhibiting AIM2 inflammasome. Furthermore, chronic LPS exposure induced the onset of neuronal ferroptosis by increasing the lipid peroxidation product MDA and regulating the ferroptosis-associated proteins Gpx4, xCT, FSP1, DMT1 and TfR, which were reversed by Rg1 treatment. Additionally, Rg1 was found to activate Nrf2 and its downstream antioxidant enzymes, such as HO1 and NQO1, both in vivo and in vitro. In vitro studies also showed that the Nrf2 inhibitor ML385 could inhibit the anti-inflammatory, antioxidant, and anti-ferroptosis effects of Rg1. CONCLUSIONS: This study demonstrated that Rg1 administration ameliorated chronic LPS-induced cognitive deficits and neuronal ferroptosis in mice by inhibiting neuroinflammation and oxidative stress. The underlying mechanisms may be related to the inhibition of AIM2 inflammasome and activation of Nrf2 signaling. These findings provide valuable insights into the treatment of chronic neuroinflammation and associated NDDs.


Assuntos
Disfunção Cognitiva , Ferroptose , Ginsenosídeos , Fator 2 Relacionado a NF-E2 , Neurônios , Transdução de Sinais , Animais , Ginsenosídeos/farmacologia , Fator 2 Relacionado a NF-E2/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/metabolismo , Transdução de Sinais/efeitos dos fármacos , Camundongos , Masculino , Ferroptose/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Lipopolissacarídeos/toxicidade , Camundongos Endogâmicos C57BL , Inflamação/tratamento farmacológico , Inflamação/metabolismo , Doenças Neuroinflamatórias/tratamento farmacológico , Doenças Neuroinflamatórias/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Linhagem Celular , Anti-Inflamatórios/farmacologia , Proteínas de Ligação a DNA
3.
J Hazard Mater ; 466: 133619, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38310841

RESUMO

Soil remediation techniques are promising approaches to relieve the adverse environmental impacts in soils caused by neonicotinoids application. This study systematically investigated the remediation mechanisms for peanut shell biochar (PSB) and composted chicken manure (CCM) on neonicotinoid-contaminated soils from the perspective of transformation of geochemical fractions by combining a 3-step sequential extraction procedure and non-steady state model. The neonicotinoid geochemical fractions were divided into labile, moderate-adsorbed, stable-adsorbed, bound, and degradable fractions. The PSB and CCM addition stimulated the neonicotinoid transformation in soils from labile fraction to moderate-adsorbed and stable-adsorbed fractions. Compared with unamended soils, the labile fractions decreased from 47.6% ± 11.8% of the initial concentrations to 12.1 ± 9.3% in PSB-amended soils, and 7.1 ± 4.9% in PSB and CCM-amended soils, while the proportions of moderate-adsorbed and stable-adsorbed fractions correspondingly increased by 1.8-2.4 times and 2.3-4.8 times, respectively. A small proportion (<4.8%) in bound fractions suggested there were rather limited bound-residues after 48 days incubation. The PSB stimulated the -NO2-containing neonicotinoid-degraders, which promoted the degradable fractions of corresponding neonicotinoids by 8.2 ± 6.3%. Degradable fraction of neonicotinoids was the dominant fate in soils, which accounted for 58.3 ± 16.7%. The findings made beneficial theoretical supplements and provided valuable empirical evidence for the remediation of neonicotinoid-contaminated soils.


Assuntos
Arachis , Poluentes do Solo , Animais , Esterco , Galinhas , Poluentes do Solo/análise , Carvão Vegetal/química , Solo/química , Neonicotinoides
4.
J Ethnopharmacol ; 324: 117794, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38244950

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Ginseng (Panax ginseng C. A. Meyer) is a precious traditional Chinese medicine with multiple pharmacological effects. Ginsenoside Rg1 is a main active ingredient extracted from ginseng, which is known for its age-delaying and antioxidant effects. Increasing evidence indicates that Rg1 exhibits anti-inflammatory properties in numerous diseases and may ameliorate oxidative damage and inflammation in many chronic liver diseases. AIM OF THE STUDY: Chronic inflammatory injury in liver cells is an important pathological basis of many liver diseases. However, its mechanism remains unclear and therapeutic strategies to prevent its development need to be further explored. Thus, our study is to delve the protective effect and mechanism of Rg1 against chronic hepatic inflammatory injuries induced by lipopolysaccharide (LPS). MATERIALS AND METHODS: The chronic liver damage model in mice was build up by injecting intraperitoneally with LPS (200 µg/kg) for 21 days. Serum liver function indicators and levels of IL-1ß, IL-6 and TNF-α were examined by using corresponding Kits. Hematoxylin and Eosin (H&E), Periodic acid-Schiff (PAS), and Masson stains were utilized to visualize hepatic histopathological damage, glycogen deposition, and liver fibrosis. The nuclear import of p-Nrf2 and the generation of Col4 in the liver were detected by IF, while IHC was employed to detect the expressions of NLRP3 and AIM2 in the hepatic. The Western blot and q-PCR were used to survey the expressions of proteins and mRNAs of fibrosis and apoptosis, and the expressions of Keap1, p-Nrf2 and NLRP3, NLRP1, AIM2 inflammasome-related proteins in mouse liver. The cell viability of human hepatocellular carcinoma cells (HepG2) was detected by Cell Counting Kit-8 to select the action concentration of LPS, and intracellular ROS generation was detected using a kit. The expressions of Nuclear Nrf2, HO-1, NQO1 and NLRP3, NLRP1, and AIM2 inflammasome-related proteins in HepG2 cells were detected by Western blot. Finally, the feasibility of the molecular interlinking between Rg1 and Nrf2 was demonstrated by molecular docking. RESULTS: Rg1 treatment for 21 days decreased the levels of ALT, AST, and inflammatory factors of serum IL-1ß, IL-6 and TNF-α in mice induced by LPS. Pathological results indicated that Rg1 treatment obviously alleviated hepatocellular injury and apoptosis, inflammatory cell infiltration and liver fibrosis in LPS stimulated mice. Rg1 promoted Keap1 degradation and enhanced the expressions of p-Nrf2, HO-1 and decreased the levels of NLRP1, NLRP3, AIM2, cleaved caspase-1, IL-1ß and IL-6 in livers caused by LPS. Furthermore, Rg1 effectively suppressed the rise of ROS in HepG2 cells induced by LPS, whereas inhibition of Nrf2 reversed the role of Rg1 in reducing the production of ROS and NLRP3, NLRP1, and AIM2 expressions in LPS-stimulated HepG2 cells. Finally, the molecular docking illustrated that Rg1 exhibits a strong affinity towards Nrf2. CONCLUSION: The findings indicate that Rg1 significantly ameliorates chronic liver damage and fibrosis induced by LPS. The mechanism may be mediated through promoting the dissociation of Nrf2 from Keap1 and then activating Nrf2 signaling and further inhibiting NLRP3, NLRP1, and AIM2 inflammasomes in liver cells.


Assuntos
Ginsenosídeos , Inflamassomos , Hepatopatias , Humanos , Camundongos , Animais , Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Lipopolissacarídeos/farmacologia , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Interleucina-6/metabolismo , Simulação de Acoplamento Molecular , Fígado , Hepatócitos/metabolismo , Hepatopatias/tratamento farmacológico , Hepatopatias/prevenção & controle , Hepatopatias/metabolismo , Cirrose Hepática/metabolismo , Fibrose
5.
Environ Pollut ; 343: 123187, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38123113

RESUMO

The widespread presence of thiacloprid (THI), a neonicotinoid, raises concerns for human health and the aquatic environment due to its persistence, toxicity, and bioaccumulation. The fate of THI in paddy multimedia systems is mainly governed by irrigation practices, but the potential impacts remain poorly documented. This study investigated the effects of water management practices on THI spatiotemporal dynamics in paddy multimedia systems by combining soil column experiments and a non-steady-state multimedia model. The results indicated the wetting-drying cycle (WDC) irrigation reduced THI occurrences in environmental phases (i.e., soil, interstitial water, and overlying water) and accelerated the THI loss through the THI aerobic degradation process. THI occurrences in the soil and water phases decreased from 18.8% for conventional flooding (CF) treatment to 9.2% for severe wetting-drying cycle (SW) treatment after 29 days, while the half-lives shortened from 11.1 days to 7.3 days, respectively. Meanwhile, the WDC decreased THI outflow from leakage water, which reduced the THI risk of leaching. There was no significant difference in THI plant uptake and volatilization between CF and WDC treatments. The mean proportions of THI fate in paddy multimedia systems followed the order: THI degradation (57.7%), outflow from leakage water (25.5%), occurrence in soil (12.4%), plant uptake (3.4%), occurrence in interstitial water (0.7%), occurrence in overlying water (0.3%), volatilization (<0.1%) after 29 days. The sensitivity analysis identified the soil organic carbon partition coefficient (KOC) as the most sensitive parameter affecting THI's fate. In addition, the topsoil layers of 0-4 cm were the main sink of THI, holding 67% of THI occurrence in the soil phase. The THI occurrence in interstitial water was distributed evenly throughout the soil profile. These findings made beneficial theoretical supplements and provided valuable empirical evidence for water management practices to reduce the THI ecological risk.


Assuntos
Oryza , Solo , Tiazinas , Humanos , Multimídia , Carbono , Água , Neonicotinoides
6.
Micromachines (Basel) ; 14(8)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37630033

RESUMO

In high-integration electronic components, the insulated-gate bipolar transistor (IGBT) power module has a high working temperature, which requires reasonable thermal analysis and a cooling process to improve the reliability of the IGBT module. This paper presents an investigation into the heat dissipation of the integrated microchannel cooling plate in the silicon carbide IGBT power module and reports the impact of the BL series micropump on the efficiency of the cooling plate. The IGBT power module was first simplified as an equivalent-mass block with a mass of 62.64 g, a volume of 15.27 cm3, a density of 4.10 g/cm3, and a specific heat capacity of 512.53 J/(kg·K), through an equivalent method. Then, the thermal performance of the microchannel cooling plate with a main channel and a secondary channel was analyzed and the design of experiment (DOE) method was used to provide three factors and three levels of orthogonal simulation experiments. The three factors included microchannel width, number of secondary inlets, and inlet diameter. The results show that the microchannel cooling plate significantly reduces the temperature of IGBT chips and, as the microchannel width, number of secondary inlets, and inlet diameter increase, the junction temperature of chips gradually decreases. The optimal structure of the cooling plate is a microchannel width of 0.58 mm, 13 secondary inlets, and an inlet diameter of 3.8 mm, and the chip-junction temperature of this structure is decreased from 677 °C to 77.7 °C. In addition, the BL series micropump was connected to the inlet of the cooling plate and the thermal performance of the microchannel cooling plate with a micropump was analyzed. The micropump increases the frictional resistance of fluid flow, resulting in an increase in chip-junction temperature to 110 °C. This work demonstrates the impact of micropumps on the heat dissipation of cooling plates and provides a foundation for the design of cooling plates for IGBT power modules.

7.
Sensors (Basel) ; 23(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37177521

RESUMO

For the demand of rapid monitoring of pollution gas disorganized emissions in industrial parks, this paper studies the solar fast tracker system of vehicle-mounted SOF-FTIR (Solar Occultation Flux Fourier Transform Infrared Spectroscopy) system, where the spectrometer directly measures the broadband absorption spectrum of solar radiation light. A fast portable solar tracking system based on PSD (position sensitive detector) is designed, the mathematical model of solar spot position on the PSD surface source is established, and the optimal optical design parameters are simulated using the model. The dead-zone integral separation PID (Proportion Integration Differentiation) control algorithm is used to track the trajectory of the solar, and the light spot position model is used to nonlinearly compensate the output of PID control so that the PID controller has the same control precision and response speed in different error areas. Experimental analysis of the solar tracking performance of the vehicle-mounted SOF-FTIR under static and dynamic conditions, as well as the spectral effects on the measurements under static vehicle, constant speed, and turning driving conditions. The remote sensing application experiment of vehicle-mounted SOF-FTIR pollution gas emission flux was carried out in a tire factory in Hefei City, Anhui Province. A vehicle-mounted SOF-FTIR system realized the qualitative and quantitative analysis of the pollution gas at the boundary of the tire plant and calculated the flux of each component pollution gas. The emission flux of pollution gas was highly consistent with the actual pollution distribution of the tire plant. The results show that the positioning accuracy of PSD in the vehicle tracking experiment can also meet SOF-FTIR requirements for solar tracking. The remote sensing system will be useful in the field of atmospheric environment monitoring, and the mobile monitoring of regional pollutant gases based on solar infrared spectroscopy has application value.

8.
Acta Pharmacol Sin ; 44(1): 157-168, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35655095

RESUMO

Hepatic steatosis plays a detrimental role in the onset and progression of alcohol-associated liver disease (ALD). Mesencephalic astrocyte-derived neurotrophic factor (MANF) is an evolutionarily conserved protein related to the unfolded protein response. Recent studies have demonstrated that MANF plays an important role in liver diseases. In this study, we investigated the role of MANF in ethanol-induced steatosis and the underlying mechanisms. We showed that the hepatic MANF expression was markedly upregulated in mouse model of ALD by chronic-plus-single-binge ethanol feeding. Moreover, after chronic-plus-binge ethanol feeding, hepatocyte-specific MANF knockout (HKO) mice displayed more severe hepatic steatosis and liver injury than wild-type (WT) control mice. Immunoprecipitation-coupled MS proteomic analysis revealed that arginosuccinate synthase 1 (ASS1), a rate-limiting enzyme in the urea cycle, resided in the same immunoprecipitated complex with MANF. Hepatocyte-specific MANF knockout led to decreased ASS1 activity, whereas overexpression of MANF contributed to enhanced ASS1 activity in vitro. In addition, HKO mice displayed unique urea cycle metabolite patterns in the liver with elevated ammonia accumulation after ethanol feeding. ASS1 is known to activate AMPK by generating an intracellular pool of AMP from the urea cycle. We also found that MANF supplementation significantly ameliorated ethanol-induced steatosis in vivo and in vitro by activating the AMPK signaling pathway, which was partly ASS1 dependent. This study demonstrates a new mechanism in which MANF acts as a key molecule in maintaining hepatic lipid homeostasis by enhancing ASS1 activity and uncovers an interesting link between lipid metabolism and the hepatic urea cycle under excessive alcohol exposure.


Assuntos
Fígado Gorduroso , Hepatopatias Alcoólicas , Animais , Camundongos , Proteínas Quinases Ativadas por AMP/metabolismo , Astrócitos/metabolismo , Etanol/toxicidade , Fígado Gorduroso/induzido quimicamente , Hepatócitos/metabolismo , Fígado/metabolismo , Camundongos Knockout , Fatores de Crescimento Neural/metabolismo , Proteômica , Ureia/metabolismo
9.
Opt Express ; 30(14): 25581-25596, 2022 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-36237085

RESUMO

Remote sensing imaging technology is one of the most powerful tools for gas leak monitoring in chemical industrial parks. In the case of leaks, it is necessary to quickly and accurately obtain detailed information of the gas cloud (volume, distribution, diffusion situation and location). This paper proposes a 3-D quantitative reconstruction method for gas clouds. Two scanning Fourier transform infrared (FTIR) remote-sensing imaging systems were used to perform telemetry experiments in a monitored space with a total volume of 314.9 m3, and the released gases were SF6 and CH4. One scanning FTIR remote-sensing imaging system can only measure a 2-D concentration-path-length product (CL) image of a 3-D gas cloud, where each pixel has attitude information of elevation and azimuth. Geometric methods are applied to locate the monitored space and construct a 3-D grid (longitude, latitude, altitude). The optical path length (OPL) sparse matrix of each layer is generated, and the concentration distribution of each layer is reconstructed by the simultaneous algebraic reconstruction technique (SART). The reconstructed results of each layer are stacked into a 3-D gas cloud and displayed on the 3-D Earth software at a set threshold. Three-dimensional leaking gas clouds (CH4, SF6) with geometric information and concentration distribution has been generated through the above processes from measurement, localization to reconstruction and display. On the premise that the gas cloud is completely covered by the field of view of each scanning system, the localization and quantification of the gas cloud is available. Then weighted concentration centers can be calculated from these gas clouds to approximate the leak source. The proposed method effectively extends the online leak monitoring application of the scanning FTIR remote-sensing imaging system.

10.
Biomed Pharmacother ; 150: 112943, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35405395

RESUMO

Acute lung injury (ALI) is an urgent respiratory disease without effective treatment. Mesencephalic astrocyte-derived neurotrophic factor (MANF)has been demonstrated to play a suppressive role in some inflammatory conditions. However, the effect of MANF on ALI has not yet been reported. In this study, we collected bronchoalveolar lavage fluid (BALF) from the patients with or without pulmonary inflammation, and used lipopolysaccharide (LPS) to induce mice ALI model. Mono-macrophage-specific MANF knockout (MKO) mice were constructed and recombinant human MANF protein was used to ALI mice. We found that the endogenous MANF protein in both human BALF and mice lung tissues was increased in inflammatory conditions. MANF level in the macrophages of inflammatory lung was higher than that in normal controls in both human and mice. MANF deficiency in macrophages induced lung inflammation and aggravated LPS-induced lung injury. MANF lowered LPS-induced lung injury, inhibited macrophage polarization to M1 functional type. Meanwhile, MANF inhibited-LPS induced activation of NF-κB signal pathway by down regulating phosphorylated p65in lung tissue and macrophages. These results indicate that MANF acts as a suppressor in ALI via negatively regulating NF-κB activation and macrophages polarization, which may be a novel potential target and shed light on ALI therapy.


Assuntos
Lesão Pulmonar Aguda , Lipopolissacarídeos , Macrófagos , Fatores de Crescimento Neural , Lesão Pulmonar Aguda/genética , Lesão Pulmonar Aguda/imunologia , Lesão Pulmonar Aguda/metabolismo , Lesão Pulmonar Aguda/patologia , Animais , Astrócitos/metabolismo , Astrócitos/patologia , Modelos Animais de Doenças , Humanos , Lipopolissacarídeos/farmacologia , Pulmão , Ativação de Macrófagos , Macrófagos/imunologia , Macrófagos/patologia , Camundongos , Camundongos Knockout , NF-kappa B/metabolismo , Fatores de Crescimento Neural/genética , Fatores de Crescimento Neural/imunologia , Fatores de Crescimento Neural/metabolismo
11.
Appl Opt ; 60(30): 9396-9403, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34807078

RESUMO

The concentration-path-length product (CL) image of the leaking gas cloud measured by the passive Fourier transform infrared (FTIR) scanning remote-sensing imaging system has a low resolution. Gas cloud diffusion is affected by wind speed and direction, which makes it difficult to trace the source of a leakage. Therefore, we propose a method to reconstruct the CL image of the leaking gas cloud applied to the passive FTIR scanning remote-sensing imaging system. First, bicubic interpolation is employed to upsample the low-resolution CL image of gas clouds. Second, the maximum noise-equivalent concentration-path-length (NECL) product is used as a threshold to segment the high-resolution gas cloud image. Third, image morphology processing and the evaluation criteria of the leaking gas cloud are applied to detect the leaking gas cloud. Finally, the high-resolution CL image of the leaking gas cloud is superimposed onto the background image. The effectiveness of the reconstruction method is proven by the SF6 remote-sensing experiment and simulation. The results show that the proposed method should be effectively implemented to reconstruct the high-resolution CL image of the leaking gas cloud. The reconstructed leaking gas cloud plume, as well as the location of the leakage source, are quite obvious. The reconstruction method has been successfully applied to passive FTIR scanning remote-sensing imaging systems, with high accuracy, in real time, and with robustness.

12.
ACS Appl Mater Interfaces ; 12(44): 49830-49839, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-33095577

RESUMO

A broadband photodetector with high performance is highly desirable for the optoelectric and sensing application. Herein, we report a "photo-thermo-electric" (PTE) detector based on an ultrathin SnTe film. The (001)-oriented SnTe films with the wafer size scale are epitaxially grown on the surface of sodium chloride crystals by a scalable sputtering method. Due to the giant PTE effect under laser spot excitation on the asymmetric position between two terminals, a built-in electrical field is produced to drive bulk carriers for a self-powered photodetector, leading to a broad spectral response in the wavelength range from 404 nm to 10.6 µm far beyond the limitation of the energy band gap. Significantly, the photodetector displays a high on/off photoswitching ratio of over 105 with a suppressed dark current, which is 4-5 orders of magnitude higher than that of other reported SnTe-based detectors. Under zero external bias, the device yields the highest detectivity of ∼1.3 × 1010 cm Hz1/2 W-1 with a corresponding responsivity of ∼3.9 mA W-1 and short rising/falling times of ∼78/84 ms. Furthermore, the photodetector transferred onto the flexible template exhibits excellent mechanical flexibility over 300 bending cycles. These findings offer feasible strategies toward designing and developing low-power-consumption wearable optoelectronics with competitive performance.

13.
Sensors (Basel) ; 20(13)2020 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-32630795

RESUMO

This paper proposes a novel capacitive liquid metal microelectromechanical system (MEMS) inclinometer sensor and introduces its design, fabrication, and signal measurement. The sensor was constructed using three-layer substrates. A conductive liquid droplet was rolled along an annular groove of the intermediate substrate to reflect angular displacement, and capacitors were used to detect the position of the droplet. The numerical simulation work provides the working principle and structural design of the sensor, and the fabrication process of the sensor was proposed. Furthermore, the static capacitance test and the dynamic signal test were designed. The sensor had a wide measurement range from ±2.12° to ±360°, and the resolution of the sensor was 0.4°. This sensor further expands the measurement range of the previous liquid droplet MEMS inclinometer sensors.

14.
ACS Appl Mater Interfaces ; 12(31): 35250-35258, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32660231

RESUMO

A broad spectral response is highly desirable for radiation detection in modern optoelectronics; however, it still remains a great challenge. Herein, we report a novel ultrabroadband photodetector based on a high-quality tin monoselenide (SnSe) thin film, which is even capable of detecting photons with energies far below its optical band gap. The wafer-size SnSe ultrathin films are epitaxially grown on sodium chloride via the 45° in-plane rotation by employing a sputtering method. The photodetector delivers sensitive detection to ultraviolet-visible-near infrared (UV-Vis-NIR) lights in the photoconductive mode and shows an anomalous response to long-wavelength infrared at room temperature. Under the mid-infrared light of 10.6 µm, the fabricated photodetector exhibits a large photoresponsivity of 0.16 A W-1 with a fast response rate, which is ∼3 orders of magnitude higher than other results. The thermally induced carriers from the photobolometric effect are responsible for the sub-bandgap response. This mechanism is confirmed by a temperature coefficient of resistance of -2.3 to 4.4% K-1 in the film, which is comparable to that of the commercial bolometric detectors. Additionally, the flexible device transferred onto polymer templates further displays high mechanical durability and stability over 200 bending cycles, indicating great potential toward developing wearable optoelectronic devices.

15.
Biosensors (Basel) ; 10(6)2020 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-32526910

RESUMO

Microelectromechanical system (MEMS) liquid sensors may be used under large acceleration conditions. It is important to understand the deformation of the liquid droplets under acceleration for the design and applications of MEMS liquid sensors, as this will affect the performance of the sensors. This paper presents an investigation into the deformation of a mercury droplet in a liquid MEMS sensor under accelerations and reports the relationship between the deformation and the accelerations. The Laminar level set method was used in the numerical process. The geometric model consisted of a mercury droplet of 2 mm in diameter and an annular groove of 2.5 mm in width and 2.5 mm in height. The direction of the acceleration causing the droplet to deform is perpendicular to the direction of gravity. Fabrication and acceleration experiments were conducted. The deformation of the liquid was recorded using a high-speed camera. Both the simulation and experimental results show that the characteristic height of the droplets decreases as the acceleration increases. At an acceleration of 10 m/s2, the height of the droplet is reduced from 2 to 1.658 mm, and at 600 m/s2 the height is further reduced to 0.246 mm. The study finds that the droplet can deform into a flat shape but does not break even at 600 m/s2. Besides, the properties of the material in the domain surrounding the droplet and the contact angle also affect the deformation of the droplet. This work demonstrates the deformation of the liquid metal droplets under acceleration and provides the basis for the design of MEMS droplet acceleration sensors.


Assuntos
Aceleração , Técnicas Biossensoriais , Mercúrio/análise , Sistemas Microeletromecânicos , Tamanho da Partícula
16.
Sensors (Basel) ; 20(9)2020 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-32375233

RESUMO

Metallic waste classification benefits the environment, resource reuse and industrial economy. This paper provides a fast, non-contact and convenient method based on eddy current to classify metals. The characteristic phase to characterize different conductivity is introduced and extracted from mutual inductance in the form of amplitude and phase. This characteristic phase could offer great separation for non-tilting metals. Although it is hard to classify tilting metals by only using the characteristic phase, we propose the technique of phase compensation utilizing photoelectric sensors to obtain the rectified phase corresponding to the non-tilting situation. Finally, we construct a classification algorithm involving phase compensation. By conducting a test, a 95 % classification rate is achieved.

17.
Nanoscale ; 12(13): 7358-7365, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32207508

RESUMO

Due to its excellent electrical and optical properties, tin selenide (SnSe), a typical candidate of two-dimensional (2D) semiconductors, has attracted great attention in the field of novel optoelectronics. However, the large-area growth of high-quality SnSe films still remains a great challenge, which limits their practical applications. Here, wafer-size SnSe ultrathin films with high uniformity and crystallization were deposited via a scalable magnetron sputtering method. The results showed that the SnSe photodetector was highly sensitive to a broad range of wavelengths in the UV-visible-NIR range, especially showing an extremely high responsivity of 277.3 A W-1 with the corresponding external quantum efficiency of 8.5 × 104% and detectivity of 7.6 × 1011 Jones. These figures of merits are among the best performances for the sputter-fabricated 2D photodetector devices. The photodetecting mechanisms based on a photogating effect induced by the trapping effect of localized defects are discussed in detail. The results indicate that the few-layered SnSe films obtained from sputtering growth have great potential in the design of high-performance photodetector arrays.

18.
Appl Opt ; 57(20): 5794-5799, 2018 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-30118050

RESUMO

Removing the baseline from the spectra, which are measured by a Fourier transform infrared spectrometer (FTIR), is an important preprocessing step for further spectra analysis such as quantitative and qualitative analysis. An automatic baseline correction method named iterative averaging, which is based on the basic knowledge of moving average, is presented. We also compared it to other methods, such as rubber band, adaptive iterative reweight penalized least squares, automatic iterative moving average, and morphological weighted penalized least squares, using simulated and experimental spectra with different signal-to-noise ratios (SNRs) to evaluate the performance of these methods by performance metrics and to select an appropriate method to analyze FTIR spectra. Performance metrics such as root-mean-square error, goodness-of-fit coefficient, and chi-square are calculated. The iterative averaging method achieves the best results, which are judged by performance metrics values, when it is applied to the FTIR spectra with different SNRs. It also can correct the baseline of the FTIR spectra automatically, and improve the capability and adaptability of the unsupervised online analysis of the FTIR system effectively.

19.
Opt Express ; 26(10): A609-A614, 2018 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-29801329

RESUMO

It's necessary to remove the baseline from the spectra, which measured by open-path Fourier transform infrared spectrometry, for further spectral analysis such as qualitative and quantitative analysis. An automatic baseline correction method, the Iterative Averaging method, is presented. Baseline corrected by this method is accurate, and it also shows more precise than other methods when it is applied to Fourier Transform Infrared experimental spectra and simulated data. This method solves the key technology of the real-time on-line spectral analysis of OP-FTIR and improves the capability and adaptability of the unsupervised on-line system effectively.

20.
Environ Sci Technol ; 50(15): 8214-22, 2016 08 02.
Artigo em Inglês | MEDLINE | ID: mdl-27384928

RESUMO

Scanning electron microscopy (SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS) depth profiling were employed to characterize the aged zerovalent iron (AZVI) samples incubated in synthetic groundwater. The AZVI samples prepared under different conditions exhibited the passive layers of different morphologies, amounts, and constituents. Owing to the accumulation of iron oxides on their surface, all the prepared AZVI samples were much less reactive than the pristine ZVI for Se(IV) removal. However, the reactivity of all AZVI samples toward Se(IV) sequestration could be significantly enhanced by applying a uniform magnetic field (UMF). Moreover, the flux intensity of UMF necessary to depassivate an AZVI sample was strongly dependent on the properties of its passive layer. The UMF of 1 mT was strong enough to restore the reactivity of the AZVI samples with Fe3O4 as the major constituent of the passive film or with a thin layer of α-Fe2O3 and γ-FeOOH in the external passive film. The flux intensity of UMF necessary to depassivate the AZVI samples would increase to 2 mT or even 5 mT if the AZVI samples were covered with passive films being thicker, denser, and contained more γ-FeOOH and α-Fe2O3. Furthermore, increasing the flux intensity of UMF facilitated the reduction of Se(IV) to Se(0) by AZVI samples.


Assuntos
Ferro/química , Espectroscopia Fotoeletrônica , Compostos Férricos , Água Subterrânea , Campos Magnéticos , Poluentes Químicos da Água/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA