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1.
J Ethnopharmacol ; 330: 118212, 2024 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-38636577

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: The combination of Aconitum carmichaelii Debx (Chuanwu, CW) and Pinellia ternata (Thunb.) Breit (Banxia, BX) forms an herbal pair within the eighteen incompatible medicaments (EIM), indicating that BX and CW are incompatible. However, the scientific understanding of this incompatibility mechanism, especially the corresponding drug-drug interaction (DDI), remains complex and unclear. AIM OF THE STUDY: This study aims to explain the DDI and potential incompatibility mechanism between CW and BX based on pharmacokinetics and cocktail approach. MATERIALS AND METHODS: Ultraperformance liquid chromatography-tandem mass spectrometry methods were established for pharmacokinetics and cocktail studies. To explore the DDI between BX and CW, in the pharmacokinetics study, 10 compounds were determined in rat plasma after administering CW and BX-CW herbal pair extracts. In the cocktail assay, the pharmacokinetic parameters of five probe substrates were utilized to assess the influence of BX on cytochrome P450 (CYP) isoenzyme (dapsone for CYP3A4, phenacetin for CYP1A2, dextromethorphan for CYP2D6, tolbutamide for CYP2C9, and omeprazole for CYP2C19). Finally, the DDI and incompatibility mechanism of CW and BX were integrated to explain the rationality of EIM theory. RESULTS: BX not only enhances the absorption of aconitine and benzoylaconine but also accelerates the metabolism of mesaconitine, benzoylmesaconine, songorine, and fuziline. Moreover, BX affects the activity of CYP enzymes, which regulate the metabolism of toxic compounds. CONCLUSIONS: BX altered the activity of CYP enzymes, consequently affecting the metabolism of toxic compounds from CW. This incompatibility mechanism may be related to the increased absorption of these toxic compounds in vivo.


Asunto(s)
Aconitum , Interacciones de Hierba-Droga , Pinellia , Ratas Sprague-Dawley , Aconitum/química , Pinellia/química , Animales , Masculino , Ratas , Sistema Enzimático del Citocromo P-450/metabolismo , Espectrometría de Masas en Tándem , Extractos Vegetales/farmacocinética , Extractos Vegetales/farmacología , Extractos Vegetales/química , Medicamentos Herbarios Chinos/farmacocinética , Medicamentos Herbarios Chinos/química , Interacciones Farmacológicas
2.
Biomed Chromatogr ; 38(5): e5847, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38368628

RESUMEN

Cnidii Fructus, derived from the dried ripe fruit of Cnidium monnieri (L.) Cuss, has the effect of warming kidneys and invigorating Yang. This study established the spectrum-effect relationships between ultra-high-performance liquid chromatography (UHPLC) fingerprints and the antitumor activities of Cnidii Fructus on human hepatocellular carcinoma (HepG2) cells. In UHPLC fingerprints, 19 common peaks were obtained, and 17 batches of herbs had similarity >0.948. In Cell Counting Kit-8 (CCK-8) test, 17 batches of Cnidii Fructus extract significantly inhibited the proliferation of HepG2 cells to different degrees, showing different half-maximal inhibitory concentration (IC50) values. Furthermore, gray correlation analysis, Pearson's analysis, and orthogonal partial least squares discriminant analysis were performed to screen out eight components. The analysis of mass spectrum data and a comparison with standards revealed that the eight components were methoxsalen, isopimpinellin, osthenol, imperatorin, osthole, ricinoleic acid, linoleic acid, and oleic acid. The verification experiments by testing single compounds indicated that these eight compounds were the major anti-hepatoma compounds in Cnidii Fructus. This work provides a model combining UHPLC fingerprints and antitumor activities to study the spectrum-effect relationships of Cnidii Fructus, which can be used to determine the principal components responsible for the bioactivity.


Asunto(s)
Proliferación Celular , Cnidium , Cromatografía Líquida de Alta Presión/métodos , Humanos , Células Hep G2 , Proliferación Celular/efectos de los fármacos , Cnidium/química , Frutas/química , Medicamentos Herbarios Chinos/farmacología , Medicamentos Herbarios Chinos/química , Neoplasias Hepáticas/tratamiento farmacológico , Carcinoma Hepatocelular/tratamiento farmacológico , Extractos Vegetales/farmacología , Extractos Vegetales/química , Reproducibilidad de los Resultados , Antineoplásicos Fitogénicos/farmacología , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/análisis , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/análisis , Furocumarinas/farmacología , Furocumarinas/análisis , Furocumarinas/química
3.
Int J Biol Macromol ; 256(Pt 1): 128431, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38029896

RESUMEN

In this study, carboxymethyl chitosan (CMCS) with excellent biocompatibility was used as the "gatekeeper" to design and fabricate a pH-responsive drug delivery system (CMCS-DFNS) as paclitaxel carriers. Characterization results showed that CMCS-DFNS was successfully prepared and the nanocarriers displayed excellent drug loading efficiency of 19.8 %, and the results of the adsorption mechanism revealed that the adsorption of PTX was consistent with the Freundlich isotherm and pseudo-second-order kinetic model. Furthermore, the pH-responsive controlled release behavior at different pH (pH = 7.4, 6.5, and 5.0) was evaluated, and the results demonstrated that the cumulative release at pH 5.0 was 58.8 %, which was 2.7 times higher than that at pH 7.4, suggesting that the carrier exhibited a good pH sensitivity. The results of in vitro cellular experiments further indicated that CMCS-DFNS significantly improved the drug uptake efficiency in breast cancer MCF-7 cells. Importantly, the results of in vivo and cellular pharmacokinetic revealed that CMCS-DFNS can improve the circulation time and enhance the relative bioavailability of paclitaxel. Therefore, the fabricated pH-responsive drug delivery system has potential applications in the delivery of anti-tumor drugs, and provides a new delivery pathway for other compounds with low bioavailability.


Asunto(s)
Antineoplásicos , Quitosano , Humanos , Paclitaxel/farmacocinética , Preparaciones de Acción Retardada/farmacología , Quitosano/química , Dióxido de Silicio , Antineoplásicos/química , Sistemas de Liberación de Medicamentos , Portadores de Fármacos/química , Concentración de Iones de Hidrógeno
4.
3 Biotech ; 13(8): 274, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37457870

RESUMEN

Mesoporous silica nanoparticles (MSN) have attracted widespread attention in the field of drug delivery and biomedicine due to their unique structure and physicochemical properties. However, MSN still have shortcomings, such as premature drug release, poorly controlled release ability and poor targeting. Therefore, in order to reduce the damage of anti-cancer drugs to normal cells, improve their utilization rate and realize their selective release in tumor cells, "gated" stimuli-responsive mesoporous silicon nanomaterials as antitumor drug delivery carriers have attracted widespread interest among researchers. The "gated" stimuli-responsive nanovalves drug delivery system can only be removed under certain specific stimuli, which makes the drug maintain "zero release" before reaching the lesion site and achieve drug accumulation in tumor cells, effectively reducing the toxic and side effects on normal cells or tissues, and greatly exerting the efficacy of anti-cancer drugs. Therefore, the construction of stimuli-responsive nano-drug delivery systems have great application potential and significance in cancer treatment and controlled release of anti-cancer drugs. This review article emphasizes the research progress of the "gated" stimuli-responsive MSN (e.g. pH, redox potential, enzyme, temperature and light) or controlled drug release and cancer treatment since 2019.

5.
J Ethnopharmacol ; 313: 116589, 2023 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-37142149

RESUMEN

ETHNOPHARMACOLOGICAL RELEVANCE: Perilla Folium (PF), is a traditional medicinal material with the homology of medicine and food in China and has been widely used due to its rich nutritional content and medicinal value. The hepatoprotective effects of PF extract include their protection against acute hepatic injury, tert-butylhydroperoxide (t-BHP) induced oxidative damage, and Lipopolysaccharide (LPS) and D-galactosamine (D-GalN) induced hepatic injury have been well studied. However, there are few reports on the pharmacokinetics studies of PF extract in acute hepatic injury model rats, and the anti-hepatic injury activity of PF is still unclear. AIM OF THE STUDY: The differences in the plasma pharmacokinetic of 21 active compounds between the normal and model groups were compared, and established pharmacokinetics/pharmacodynamics (PK/PD) modeling was to analyze the hepatoprotective effects of PF. MATERIALS AND METHODS: The acute hepatic injury model was induced with an intraperitoneal injection of lipopolysaccharide (LPS) and D-galactosamine (D-GalN), and the plasma pharmacokinetics of 21 active compounds of PF were analyzed in the normal and model groups using ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS). The correlation between plasma components and hepatoprotective effects indicators (the alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactic dehydrogenase (LDH)) in the model group was also investigated and established a Pharmacokinetic/pharmacodynamic (PK/PD) correlation analysis of the hepatoprotective effects of PF. RESULTS: The results revealed that organic acid compounds possessed the characteristics of faster absorption, shorter peak time and slower metabolism, while the flavonoid compounds had slower absorption and longer peak time, and the pharmacokinetics of various components were significantly affected after modeling. The results of PK/PD modeling analysis demonstrated that the plasma drug concentration of each component existed a good correlation with the three AST, ALT, and LDH, and the lag time of the efficacy of each component is relatively long. CONCLUSIONS: The plasma drug concentration of each component existed a good correlation with the three AST, ALT, and LDH, and the lag time of the efficacy of each component is relatively long in vivo.


Asunto(s)
Enfermedad Hepática Inducida por Sustancias y Drogas , Lipopolisacáridos , Ratas , Animales , Lipopolisacáridos/farmacología , Cromatografía Liquida , Espectrometría de Masas en Tándem , Hígado , Galactosamina/toxicidad , Galactosamina/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Enfermedad Hepática Inducida por Sustancias y Drogas/metabolismo , Aspartato Aminotransferasas , Alanina Transaminasa
6.
Curr Drug Deliv ; 20(9): 1337-1350, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-35713141

RESUMEN

BACKGROUND: Mesoporous silica nanoparticles (MSNs) are one of the most promising carriers for drug delivery. MSNs have been widely used in pharmaceutical research as drug carriers because of their large pore volume, high surface area, excellent biocompatibility, nontoxicity, ease to functionalize, and sustained release effects. MSNs have attracted much attention during drug delivery because of their special structure. OBJECTIVE: The present study aimed to synthesize mesoporous silica nanoparticles (MSNs), dendritic mesoporous silica nanoparticles (DMSN), and hollow mesoporous silica nanoparticles (HMSN) through facile methods, and to compare the drug release properties of nano-porous silica with different pore structures as a stroma for PUE drug. METHODS: MSN, DMSN, and HMSN were characterized by SEM, TEM, FT-IR, nitrogen adsorptiondesorption isotherms, XRD, and zeta potential methods. Subsequently, puerarin (PUE) was used as the active ingredient and loaded into the three mesoporous materials, respectively. And, the drug delivery behavior was measured in PBS solution with different pH values. The sustained-release properties of MSN, DMSN, and HMSN loaded with PUE were investigated. Finally, the biocompatibility and stability of MSN, DMSN, and HMSN were studied by MTT assay and hemolysis assay. RESULTS: Our results showed that MSN, DMSN, and HMSN were successfully synthesized and the three types of mesoporous silica nanoparticles had higher drug loading and encapsulation efficiency. According to the first-order release equation curve and Higuchi equation parameters, the results showed that the PUE-loaded MSN, DMSN, and HMSN exhibited sustained-release properties. Finally, MTT and hemolysis methods displayed that MSN, DMSN, and HMSN had good biocompatibility and stability. CONCLUSION: In this study, MSN, DMSN, and HMSN were successfully synthesized, and to compare the drug release properties of nano-porous silica with different pore structures as a stroma for PUE drug, we provided a theoretical and practical basis for the application of PUE.


Asunto(s)
Neuropatía Hereditaria Motora y Sensorial , Nanopartículas , Humanos , Portadores de Fármacos/química , Preparaciones de Acción Retardada/química , Dióxido de Silicio/química , Espectroscopía Infrarroja por Transformada de Fourier , Hemólisis , Microesferas , Sistemas de Liberación de Medicamentos/métodos , Nanopartículas/química , Liberación de Fármacos , Porosidad
7.
Front Pharmacol ; 13: 954692, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36210842

RESUMEN

Prunus mume fructus (MF) is used in traditional Chinese medicine and food, as it exerts pharmacological effects, such as antibacterial, antioxidant, antitumour, thirst-relieving, and antidiarrheal effects. In the present study, a reliable and sensitive ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the simultaneous determination of 16 prototype components (L-(-)-malic acid, 3,4-dihydroxybenzaldehyde, protocatechuic acid, vanillic acid, caffeic acid, D-(-)-quinic acid, citric acid, ferulic acid, syringic acid, cryptochlorogenic acid, neochlorogenic acid, chlorogenic acid, amygdalin, maslinic acid, corosolic acid, and rutin) in rat plasma after oral administration of the MF extract. Plasma samples were prepared via protein precipitation using acetonitrile. The 16 components were separated on an ACQUITY UPLC BEH C18 column (2.1 × 100 mm, 1.7 µm) with a gradient mobile phase system of methanol and 0.1% (v/v) formic acid aqueous solution at a flow rate of 0.3 ml/min. All components were quantitated using Agilent Jet Stream electrospray ionisation in negative ion mode. The intra-day and inter-day accuracies ranged from-9.4 to 9.4%, and the precision of the analytes was less than 14.8%. The extraction recovery rate of the analytes ranged from 63.59 to 109.44% and the matrix effects ranged from 49.25 to 109.28%. Stability studies proved that the analytes were stable under the tested conditions, with a relative standard deviation lower than 13.7%. Hence, the developed method was successfully applied to evaluate the pharmacokinetics of 16 components in the MF extract after oral administration in rats using UPLC-MS/MS.

8.
Molecules ; 27(19)2022 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-36234881

RESUMEN

Mume Fructus is a well-known herbal medicine and food with a long history of processing and application. Different processing methods impact the intrinsic quality of Mume Fructus. Thus, it is of great significance to investigate the changes in chemical components during processing (i.e., raw compared to the pulp and charcoal forms). In this study, plant metabolomics methods based on mass spectrometry detection were established to analyze the chemical ingredients of Mume Fructus comprehensively. Chemometric strategies were combined to analyze the profile differences of Mume Fructus after different processing methods. The established strategy identified 98 volatile and 89 non-volatile compounds of Mume Fructus by gas chromatography-mass spectrometry (GC-MS) and ultra-high performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UHPLC-Q-TOF-MS/MS), respectively. Moreover, the orthogonal partial least squares discriminant analysis (OPLS-DA) indicated that raw Mume Fructus and the Mume Fructus pulp and charcoal were distributed in three regions. Subsequently, 19 volatile and 16 non-volatile components were selected as potential chemical component markers with variable importance in the projection using (VIP) >1 as the criterion, and the accuracy was verified by a Back Propagation Neural Network (BP-NN). To further understand the difference in the content of Mume Fructus before and after processing, 16 non-volatile chemical component markers were quantitatively determined by ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS/MS). The results revealed that, compared with raw Mume Fructus, the total content of 16 components in the pulp of Mume Fructus increased while it decreased in the charcoal. Therefore, this study used GC-MS, UHPLC-Q-TOF-MS/MS and UHPLC-MS/MS modern technology to analyze the differences in chemical components before and after the processing of Mume Fructus and provided a material basis for further research on the quality evaluation and efficacy of Mume Fructus.


Asunto(s)
Medicamentos Herbarios Chinos , Espectrometría de Masas en Tándem , Carbón Orgánico , Quimiometría , Cromatografía Líquida de Alta Presión/métodos , Medicamentos Herbarios Chinos/química , Metabolómica/métodos , Espectrometría de Masas en Tándem/métodos
9.
ACS Appl Mater Interfaces ; 14(33): 38302-38310, 2022 Aug 24.
Artículo en Inglés | MEDLINE | ID: mdl-35943401

RESUMEN

Localized surface plasmon resonance (LSPR) has been demonstrated to be highly effective in the initialization or acceleration of chemical reactions because of its unique optical properties. However, because of the ultrashort lifetime (fs to ps) of plasmon-generated hot carriers, the potential of LSPR in photochemical reactions has not been fully exploited. Herein, we demonstrate an acceleration of the plasmon-mediated reduction of p-nitrothiophenol (PNTP) molecules on the surface of silver nanoparticles (AgNPs) with in situ Raman spectroscopy. p-Mercaptophenylboronic acid (PMPBA) molecules coadsorbed on AgNP surfaces act as a molecular cocatalyst in the plasmon-mediated reaction, resulting in a boosting of the PNTP reduction. This boosting is attributed to the improved transfer and separation of the plasmon-generated hot carriers at the interface of the AgNPs and coadsorbed PMPBA molecules. Our finding provides a highly simple, cost-effective, and highly effective strategy to promote plasmonic photochemistry by introducing a molecular cocatalyst, and this strategy can be extended to promote various plasmon-mediated reactions.

10.
J Agric Food Chem ; 70(28): 8838-8853, 2022 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-35801594

RESUMEN

Perilla frutescens (L.) Britt. is a plant that has been classified as one of the "One Root of Medicine and Food", and it can be used both as medicine and as food. To explore the influence of different varieties and harvest periods on the quality of different medicinal parts of P. frutescens, a comprehensive study on the chemical constituents of P. frutescens based on plant metabolomics was conducted. A total of 57 nonvolatile chemical components and 105 volatile chemical components of P. frutescens were characterized by ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) and gas chromatography-mass spectrometry (GC-MS). Furthermore, 35, 27, and 2 nonvolatile constituents as well as 16, 16, and 18 volatile constituents were identified as potential markers for discriminating P. frutescens between different medicinal parts, different varieties, and different harvest periods, respectively. Besides, 22 bioactive compounds of P. frutescens were quantitatively determined by a new sensitive UPLC-MS/MS method. This study comprehensively compares the differences and similarities of P. frutescens among the different medicinal parts, different varieties, and different harvest periods, and the results of this study may provide a theoretical basis and guidance for studying the quality evaluation and the optimization of the harvest period of this plant.


Asunto(s)
Perilla frutescens , Cromatografía Liquida , Cromatografía de Gases y Espectrometría de Masas , Perilla frutescens/química , Espectrometría de Masas en Tándem
11.
ChemSusChem ; 15(13): e202200352, 2022 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-35575041

RESUMEN

5-hydroxymethylfurfural (HMF) is considered to be one of the most pivotal multifunctional biomass platform chemicals. This Review discusses recent advances in catalytic oxidation of HMF towards high-value products. The reaction mechanism of different noble metals and the path of HMF oxidation to high-value products have been deeply investigated in the noble metal catalytic system. The reaction mechanisms of different noble metals and HMF conversion paths were compared in detail. Moreover, the factors affecting the performance of different noble metal catalysts were summarized. Finally, effective strategies were put forward to improve the catalytic performance of noble metal catalysts. The purpose is to provide a valuable reference for the academic research on the preparation of oxidation products from biomass-based HMF and the industrial application of noble metal catalysts.


Asunto(s)
Furaldehído , Metales , Catálisis , Furaldehído/análogos & derivados , Oxidación-Reducción
12.
Macromol Rapid Commun ; 43(17): e2200212, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35318764

RESUMEN

Organic electrochemical transistors (OECTs), especially the ones with high transconductance, are highly promising in sensitive detection of chemical and biological species. However, it is still a great challenge to design and fabricate OECTs with very high transconductance. Herein, an OECT with ultrahigh transconductance is reported by introducing ionic liquid and dodecylbenzenesulfonate (DBSA) simultaneously in poly(3,4-ethylenedioxythiophene): polystyrenesulfonate (PEDOT:PSS) as the semiconductive channel. Compared with the OECT based on pristine PEDOT:PSS, the OECT based on co-doped PEDOT:PSS demonstrates a significant enhancement of transconductance from 1.85 to 22.7 mS, because of the increase in volumetric capacitance and conductivity. The enhanced transconductance is attributed to the DBSA-facilitated phase separation between the ionic liquid and PEDOT:PSS, which helps to form conductive domains of ionic liquid in PEDOT:PSS matrix, and the partial dispersion of ionic liquid in the PEDOT:PSS phase. Furthermore, by using the interdigitated electrodes as the source and drain electrodes, an ultrahigh transconductance of 180 mS is obtained, which is superior to that of the state-of-the-art OECTs. Because of the ultrahigh transconductance, the obtained OECT demonstrates sensitive detection of hydrogen peroxide and glucose, making it promising in clinical diagnosis, health monitoring, and environmental surveillance.


Asunto(s)
Líquidos Iónicos , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Electrodos , Polímeros/química
13.
Phys Chem Chem Phys ; 23(46): 26385-26391, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34792049

RESUMEN

Effective charge separation is essential in plasmon-mediated photochemistry and is usually achieved by constructing plasmon-semiconductor interfaces, which is usually challenging. In this work, by monitoring the plasmon-mediated silver oxidation with in situ Raman spectroscopy, we demonstrate that the adsorbed thiophenol molecules could modulate the rate of photochemical reactions by tuning the charge separation at the plasmon-molecule interfaces. It is found that the thiophenol molecules with strong electron-withdrawing or donating functional groups could accelerate or decelerate the rate of plasmon-mediated silver oxidation, respectively. Owing to the easy tuning of the electronic structures of organic molecules via substitution, our method provides a versatile and convenient approach for the fine modulation of plasmon-mediated photochemical reactions.

14.
Nanoscale ; 13(36): 15151-15176, 2021 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-34486634

RESUMEN

In the family of Janus nanomaterials, Janus nanosheets possess not only the advantages of Janus nanomaterials, but also the advantages of two-dimensional nanosheets, endowing them with many extraordinary properties. Therefore, Janus nanosheets have great potential in the fields of interfacial engineering, catalysis, and molecular recognition. This review summarizes and discusses the recent advances in both the preparation and applications of freestanding Janus nanosheets. After a short introduction to different types of Janus nanosheets, a variety of methods for preparing freestanding Janus nanosheets are introduced, including the surface reaction, interface reaction, emulsion reaction, self-assembly, and stripping of non-Janus nanosheets, as well as selective grafting of existing Janus nanosheets. Then, the wide applications of Janus nanosheets in the fields of emulsification, catalysis, polymer reinforcement, nanomotors, and molecular recognition are summarized in detail. Finally, a discussion on the remaining challenges and future perspectives in this field is included. This review will not only deepen the understanding of Janus nanosheets, but also benefit the designs and fabrications of extraordinary and multi-functional Janus nanosheets.

15.
Chem Asian J ; 16(22): 3748-3753, 2021 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-34549536

RESUMEN

Bismuth-based compounds possess layered structures with a variety of stacking modes, endowing the compounds with diverse properties. As one type of bismuth oxysulfides, Bi9 O7.5 S6 nanocrystals has great applications in photodetection; however, the responsivity of bulky Bi9 O7.5 S6 is limited due to the poor charge separation. Herein, single-crystalline Bi9 O7.5 S6 thin nanosheets are successfully synthesized by using a solvothermal method. The thickness of the obtained Bi9 O7.5 S6 nanosheets is down to 15 nm and can be easily tuned by varying the reaction period. Moreover, the Bi9 O7.5 S6 nanosheets show strong light absorption in the visible and near infrared range, making it a promising candidate in optoelectronics. As a demonstration, the thin Bi9 O7.5 S6 nanosheets are used as active layer in an optoelectronic device, which exhibits sensitive photoelectric response to light in a wide range of 400-800 nm. The responsivity of the device reaches up to 1140 µA W-1 , and the performance of the device is stable after long-period illumination. This work demonstrates a great potential of the thin Bi9 O7.5 S6 nanosheets in optoelectronic devices, and these nanosheets may also be extended to various optoelectronic applications.

16.
ACS Nano ; 15(3): 5661-5670, 2021 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-33691064

RESUMEN

Single and a few atomic-layer molybdenum disulfide (MoS2) is a promising material in the fields of hydrogen generation, battery, supercapacitor, and environmental protection, owing to the outstanding electronic, optical, and catalytic properties. Although many approaches have been developed for exfoliation of MoS2 sheets, it is still essential to develop simple, convenient, and environmental friendly exfoliation methods. More importantly, the microscopic exfoliation process and the mechanism are still not clear, limiting a deeper understanding of the exfoliation. Herein, we develop a convenient and clean method for exfoliation of the 2H phase MoS2 (2H-MoS2) deposited on an indium tin oxide (ITO) surface. Importantly, the exfoliation process is observed directly and continuously under an optical microscope to reveal the detailed exfoliation process and mechanism. As illustrated, the light illumination triggers the exfoliation of the 2H-MoS2 sheets, and the presence of water is essential in this exfoliation process. The light intensity and wavelength, humidity, and bias all affect the exfoliation process obviously. The exfoliation is caused by the vaporization of the water molecules intercalated in 2H-MoS2 interlayers. By using this method, 2H-MoS2 nanosheets with different thicknesses are prepared on the ITO substrate, and microscopic catalysis mapping of the exfoliated sheets is demonstrated with single-molecule fluorescence microscopy, revealing that the prepared thin-layer 2H-MoS2 nanosheets show improved electrocatalysis activity (roughly 20 times). Our work will not only help deepen the understanding of exfoliation process of two-dimensional nanosheets but also provide an effective tool for the in situ study of various properties of the exfoliated sheets.

17.
World J Clin Cases ; 9(35): 10948-10955, 2021 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-35047605

RESUMEN

BACKGROUND: Serum gastrin-17 (G-17), pepsinogen I (PGI), and pepsinogen II (PGII) concentrations regulate gastric acid secretion, and hypersecretion of gastric acid increases the risks of peptic ulcer and upper gastrointestinal bleeding. These associations suggest that serum G-17, PGI, and (or) PGII may predict gastrointestinal bleeding risk among peptic ulcer patients. AIM: To evaluate the efficacies of serum G-17, PGI, PGII, and PGI/PGII ratio (PGR) for predicting upper gastrointestinal bleeding among peptic ulcer patients. METHODS: A total of 199 patients diagnosed with peptic ulcer confirmed by gastroscopy and positivity for Helicobacter pylori by the 14C-urea breath test were recruited, including 107 patients with simple peptic ulcer and 92 cases complicated by upper gastrointestinal bleeding. Serum PGI, PGII, G-17, and PGR were measured by immune methods and compared between bleeding and non-bleeding groups by univariate analysis. The specificity and sensitivity of PGs and G-17 for evaluating upper gastrointestinal bleeding risk were then assessed by constructing receiver operating characteristic (ROC) curves. RESULTS: Serum G-17 was significantly higher among peptic ulcer patients with upper gastrointestinal bleeding compared to simple peptic ulcer patients (25.34 ± 14.29 vs 8.84 ± 8.03 pmol/L, t = 9.822, P < 0.01), whereas serum PGI, PGII, and PGR did not differ significantly between bleeding and non-bleeding groups (all P > 0.05). The risk of bleeding was significantly higher among peptic ulcer patients with elevated serum G-17 (> 15 pmol/L) compared to patients with normal or low serum G-17 (73.2% vs 27.4%, χ 2 = 40.72, P < 0.01). The area under the ROC curve for serum G-17 was 0.866 ± 0.024, and a cut-off of 9.86 pmol/L yielded 90.2% sensitivity and 68.2% specificity for distinguishing peptic ulcer with and without upper gastrointestinal bleeding. CONCLUSION: Serum G-17 is significantly upregulated in peptic ulcer patients and higher levels are predictive of upper gastrointestinal bleeding. Conversely, serum PGI, PGII, and PGR have no predictive value. Further prospective studies are warranted to examine if high G-17 can be used to assess risk of bleeding prior to onset.

18.
J Phys Chem Lett ; 11(18): 7650-7656, 2020 Sep 17.
Artículo en Inglés | MEDLINE | ID: mdl-32820939

RESUMEN

A surface plasmon can drive many photochemical reactions, in which effective charge separation and migration is a key. In analogy to the plasmon-semiconductor interface, the plasmon-molecule interface may also be used to improve the separation and migration of hot carriers. In this work, by using in situ Raman spectroscopy, molecular grafting on silver nanostructures is found essential for modulating the charge separation and p-aminothiophenol (PATP) oxidation reaction. When the LUMO of the grafted molecules match well the energy distribution of the plasmon-generated hot electrons, the PATP oxidation process accelerates significantly. Moreover, compared with symmetrical grafting, asymmetrical grafting is more effective in regulating the charge separation and plasmon-mediated chemical reaction. This work provides an effective strategy for deep understanding and fine modulation of plasmon-mediated photochemistry.

19.
RSC Adv ; 8(55): 31594-31602, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-35548211

RESUMEN

Three-dimensional (3D) hierarchical CoMn2O4@Co3O4 core/shell nanoneedle/nanosheet arrays for high-performance supercapacitors were designed and synthesized on Ni foam by a two-step hydrothermal route. The hybrid nanostructure exhibits much more excellent capacitive behavior compared with either the pristine CoMn2O4 nanoneedle arrays alone or Co3O4 nanosheets alone. The formation of an interconnected pore hybrid system is quite beneficial for the facile electrolyte penetration and fast electron transport. The CoMn2O4@Co3O4 electrode can achieve a high specific capacitance of 1627 F g-1 at 1 A g-1 and 1376 F g-1 at 10 A g-1. In addition, an asymmetric supercapacitor (ASC) was assembled by using the CoMn2O4@Co3O4 core/shell hybrid nanostructure arrays on Ni foam as a positive electrode and activated carbon as a negative electrode in an aqueous 3 M KOH electrolyte. A specific capacitance of 125.8 F g-1 at 1 A g-1 (89.2% retention after 5000 charge/discharge cycles at a current density of 2 A g-1) and a high energy density of 44.8 W h kg-1 was obtained. The results indicate that the obtained unique integrated CoMn2O4@Co3O4 nanoarchitecture may show great promise as ASC electrodes for potential applications in energy storage.

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