Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Small ; 19(25): e2300289, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-36929092

RESUMEN

Dual single atoms catalysts have promising application in bifunctional electrocatalysis due to their synergistic effect. However, how to balance the competition between rate-limiting steps (RDSs) of reversible oxygen reduction and oxygen evolution reaction (OER) and fully expose the active centers by reasonable structure design remain enormous challenges. Herein, Fe/N4 and Ni/N4 sites separated on different sides of the carbon nanosheets with Janus structure (FeNijns /NC) is synthesized by layer-by-layer assembly method. Experiments and calculations reveal that the side of Fe/N4 is beneficial to oxygen reduction reaction (ORR) and the Ni/N4 side is preferred to OER. Such Janus structure can take full advantage of two separate-sides of carbon nanosheets and balance the competition of RDSs during ORR and OER. FeNijns /NC possesses superior ORR and OER activity with ORR half-wave potential of 0.92 V and OER overpotential of 440 mV at J = 10 mA cm-2 . Benefiting from the excellent bifunctional activities, FeNijns /NC assembled aqueous Zn-air battery (ZAB) demonstrates better maximum power density, and long-term stability (140 h) than Pt/C+RuO2 catalyst. It also reveals superior flexibility and stability in solid-state ZAB. This work brings a novel perspective for rational design and understanding of the catalytic mechanisms of dual single atom catalysts.

2.
BMC Complement Altern Med ; 18(1): 51, 2018 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-29402262

RESUMEN

BACKGROUND: In China, Panax notoginseng has been used to treat oxidative stress-related diseases for a long time. Panax notoginseng saponins is an extract from Panax notoginseng Ledeb. Its therapeutic potential is related to antioxidant activity, but related mechanisms are still unclear. The study aims to assess the protection effects of Panax notoginseng saponins in the taurocholate-induced rat model of acute pancreatitis (AP) and explore underlying mechanisms. METHODS: A rat model of severe acute pancreatitis (SAP) was established in rats induced with taurocholate. Panax notoginseng saponins was firstly administered in the treatment group via intravenous injection. After 2 h, taurocholate administration was performed. After 24 h, the expression levels of miR-181b, Beclin1, LC3-II, Akt and mTOR from pancreas tissues were measured by Western Blotting and RT-PCR. Then the expression levels of Caspase-3 and Blc-2 were determined by immunohistochemistry. Apoptosis was assessed by the TUNEL assay. Amylase and lipase in serum were determined by ELISA and pancreatic water contents in pancreatic tissue were measured. After eosin and hematoxylin staining, the histologic analysis was performed. RESULTS: After SAP induction by taurocholate and the treatment with Panax notoginseng saponins for 24 h, we detected the up-regulated miR-181b, the reduced Bcl-2 expression, the increased activity of mTOR/Akt, the blocked Beclin1 and LC3-II expressions, and the enhanced Caspase-3 expression. Serum lipase and amylase levels were significantly decreased in the treatment group of Panax notoginseng saponins compared to the control group. Histological analysis results verified the attenuation effects of Panax notoginseng saponins on taurocholate-induced pancreas injury, apoptosis, and autophagy. CONCLUSION: By up-regulating the miR-181b expression level, Panax notoginseng saponins significantly reduced taurocholate-induced pancreas injury and autophagy and increased apoptosis. The significant protection effects of Panax notoginseng saponins suggested its potential in treating taurocholate induced-acute pancreatitis.


Asunto(s)
Caspasa 3/metabolismo , MicroARNs/metabolismo , Panax notoginseng , Pancreatitis/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Saponinas/farmacología , Serina-Treonina Quinasas TOR/metabolismo , Animales , Línea Celular , Modelos Animales de Enfermedad , Masculino , MicroARNs/genética , Páncreas/efectos de los fármacos , Páncreas/patología , Pancreatitis/patología , Extractos Vegetales , Ratas , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Ácido Taurocólico/efectos adversos
3.
J Colloid Interface Sci ; 672: 329-337, 2024 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-38850860

RESUMEN

Mussel-inspired polydopamine (PDA) coating has been utilized extensively as versatile deposition strategies that can functionalize surfaces of virtually all substrates. However, the strong adhesion, stability and intermolecular interaction of PDA make it inefficient in certain applications. Herein, a green and efficient photocatalytic method was reported to remove adhesion and degrade PDA by using TiO2-H2O2 as photocatalyst. The photodegradation process of the PDA spheres was first undergone nanoscale disassembly to form soluble PDA oligomers or well-dispersed nanoparticles. Most of the disassembled PDA can be photodegraded and finally mineralized to CO2 and H2O. Various PDA coated templates and PDA hollow structures can be photodegraded by this strategy. Such process provides a practical strategy for constructing the patterned and gradient surfaces by the "top-down" method under the control of light scope and intensity. This sequential degradation strategy is beneficial to achieve the decomposition of highly crosslinked polymers.

4.
ACS Appl Mater Interfaces ; 16(15): 18703-18712, 2024 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-38591147

RESUMEN

Atomically dispersed dual-site catalysts can regulate multiple reaction processes and provide synergistic functions based on diverse molecules and their interfaces. However, how to synthesize and stabilize dual-site single-atom catalysts (DACs) is confronted with challenges. Herein, we report a facile high-temperature gas-migration strategy to synthesize Fe-Ni DACs on nitrogen-doped carbon nanosheets (FeNiSAs/NC). FeNiSAs/NC exhibits a high half-wave potential (0.88 V) for the oxygen reduction reaction (ORR) and a low overpotential of 410 mV at 10 mA cm-2 for the oxygen evolution reaction (OER). As an air electrode for Zn-air batteries (ZABs), it shows better performances in aqueous ZABs and excellent stability and flexibility in solid-state ZABs. The high specific surface area (1687.32 m2/g) of FeNiSAs/NC is conducive to electron transport. Density functional theory (DFT) reveals that the Fe sites are the active center, and Ni sites can significantly optimize the free energy of the oxygen-containing intermediate state on Fe sites, contributing to the improvement of ORR and the corresponding OER activities. This work can provide guidance for the rational design of DACs and understand the structure-activity relationship of SACs with multiple active sites for electrocatalytic energy conversion.

5.
J Colloid Interface Sci ; 650(Pt A): 934-942, 2023 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-37453317

RESUMEN

Single atoms catalysts (SACs) have promising development in electrocatalytic energy conversion. Nevertheless, rational design SACs with reversible oxygen electrocatalysis still remain challenge. Herein, we synthesized atomically dispersed Zn with N defect on three-dimensional (3D) biomimetic carbon nanotubes by secondary pyrolysis (Zn-N-C-2), which possesses excellent oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) bifunctional catalytic activities. The biomimetic 3D structure and unique "leaf-branch" system are beneficial to fully expose the active sites. Density functional theory (DFT) calculations show that Zn-N3-D can optimize the charge distribution and facilitate electron transfer step of OH*→O*. Zn-N-C-2 exhibits higher ORR activity than commercial Pt/C with a half-wave potential (E1/2) of 0.85 V and OER overpotential of 450 mV at 10 mA cm-2. After being assembled into the air cathode of aqueous Zn-air battery (ZAB), it demonstrates superior performances with long-term charge and discharge for more than 200 h. This work not only clarifies the controlled synthesis of N-defects Zn SACs with excellent bifunctional electrocatalyst, but also provide in-depth understanding of structural-performance relationships by regulating local microenvironments.

6.
Photodiagnosis Photodyn Ther ; 29: 101649, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-31911237

RESUMEN

OBJECTIVE: To observe the efficiency and safety of hematoporphyrin mono-methylether photodynamic therapy (HMME-PDT) in treating port-wine stains (PWS) with Chinese patients, and to evaluate the advantage of photograph,VISIA Complexion Analysis System, and dermoscopy in efficacy evaluation.Analyzing changes of pain during treatment and related adverse reactions. METHOD: 62 patients were treated in our department during2017-2019 with HMME-PDT, among which, 20 cases were pink type, 32 cases were purple type and remain 11 cases were nodular thickening type. Initially, all patients received an intravenous injection of 5 mg/kg HMME, and then the lesion areas of the patients were exposed to 532 nm LED green light after 10 min. The irradiation power density was range between 80-100 mW/cm2. By utilization of photograph,VISIA system, and dermoscopy to evaluate the clearance after treatments, and then informing the patients to value the pain level during the treatment via visual analogue scale(VAS), and recording the adverse reactions. RESULT: After 2 times treatments, 11 of the 62 cases were cured (17.74 %), 17 cases showed a good efficacy (27.42 %), 20 cases indicated alleviation (32.26 %), while 14 cases displayed no efficacy (22.58 %).By observation, The VISIA system combined with image analysis software is an excellent technique in assessing efficacy. Dermoscopy helps to classify PWS types.It showed that the pain level each patient could endure was distinct, and it's remarkable that when receiving consecutive 12.09 ± 3.74 min of treatment, most of patients have showed severe pain.Patients with severe pain except young children who couldn't value the pain, had better efficacy.The side effects after treatment mainly displayed with edema, crust, hyperpigmentation. No recurrence within 2 years. CONCLUSION: It shows that after treating with HMME-PDTt efficacy is remarkable, with advantage of safety and fewer side effects. HMME_PDT should undergo further research and promotion. VISIA system combined with image analysis software and dermoscopy are excellent techniques for evaluating efficacy.


Asunto(s)
Hematoporfirinas/administración & dosificación , Fármacos Fotosensibilizantes/administración & dosificación , Mancha Vino de Oporto/tratamiento farmacológico , Adolescente , Adulto , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Fotoquimioterapia/métodos , Factores de Riesgo
7.
Int J Immunopathol Pharmacol ; 34: 2058738420923911, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32462952

RESUMEN

Intravenous Xuebijing (XBJ) therapy suppresses paraquat (PQ)-induced pulmonary fibrosis. However, the mechanism underlying this suppression remains unknown. This work aimed to analyze the miR-140-5p-induced effects of XBJ injection on PQ-induced pulmonary fibrosis in mice. The mice were arbitrarily assigned to four groups. The model group was administered with PQ only. The PQ treatment group was administered with PQ and XBJ. The control group was administered with saline only. The control treatment group was administered with XBJ only. The miR-140-5p and miR-140-5p knockout animal models were overexpressed. The gene expression levels of miR-140-5p, transglutaminase-2 (TG2), ß-catenin, Wnt-1, connective tissue growth factor (CTGF), mothers against decapentaplegic homolog (Smad), and transforming growth factor-ß1 (TGF-ß1) in the lungs were assayed with quantitative reverse transcription polymerase chain reaction (qRT-PCR) and Western blot analysis. The levels of TGF-ß1, CTGF, and matrix metalloproteinase-9 (MMP-9) in the bronchoalveolar lavage fluid were assessed by enzyme-linked immunosorbent assay (ELISA). Hydroxyproline (Hyp) levels and pulmonary fibrosis were also scored. After 14 days of PQ induction of pulmonary fibrosis, AdCMV-miR-140-5p, and XBJ upregulated miR-140-5p expression; blocked the expressions of TG2, Wnt-1, and ß-catenin; and decreased p-Smad2, p-Smad3, CTGF, MMP-9, and TGF-ß1 expressions. In addition, Hyp and pulmonary fibrosis scores in XBJ-treated mice decreased. Histological results confirmed that PQ-induced pulmonary fibrosis in XBJ-treated lungs was attenuated. TG2 expression and the Wnt-1/ß-catenin signaling pathway were suppressed by the elevated levels of miR-140-5p expression. This inhibition was pivotal in the protective effect of XBJ against PQ-induced pulmonary fibrosis. Thus, XBJ efficiently alleviated PQ-induced pulmonary fibrosis in mice.


Asunto(s)
Medicamentos Herbarios Chinos/uso terapéutico , MicroARNs/biosíntesis , Paraquat/toxicidad , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/prevención & control , Células A549 , Animales , Líquido del Lavado Bronquioalveolar/química , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , MicroARNs/efectos de los fármacos , MicroARNs/genética , Fibrosis Pulmonar/patología , Transducción de Señal/efectos de los fármacos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA