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1.
DNA Res ; 31(3)2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38600880

RESUMEN

We report the complete telomere-to-telomere genome assembly of Oldenlandia diffusa which renowned in traditional Chinese medicine, comprising 16 chromosomes and spanning 499.7 Mb. The assembly showcases 28 telomeres and minimal gaps, with a total of only five. Repeat sequences constitute 46.41% of the genome, and 49,701 potential protein-coding genes have been predicted. Compared with O. corymbosa, O. diffusa exhibits chromosome duplication and fusion events, diverging 20.34 million years ago. Additionally, a total of 11 clusters of terpene synthase have been identified. The comprehensive genome sequence, gene catalog, and terpene synthase clusters of O. diffusa detailed in this study will significantly contribute to advancing research in this species' genetic, genomic, and pharmacological aspects.


Asunto(s)
Genoma de Planta , Telómero , Telómero/genética , Transferasas Alquil y Aril/genética , Duplicación Cromosómica
2.
Nat Commun ; 15(1): 1747, 2024 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-38409100

RESUMEN

Energy transfer is a ubiquitous phenomenon that delivers energy from a blue-shifted emitter to a red-shifted absorber, facilitating wide photonic applications. Two-dimensional (2D) semiconductors provide unique opportunities for exploring novel energy transfer mechanisms in the atomic-scale limit. Herein, we have designed a planar optical microcavity-confined MoS2/hBN/WS2 heterojunction, which realizes the strong coupling among donor exciton, acceptor exciton, and cavity photon mode. This configuration demonstrates an unconventional energy transfer via polariton relaxation, brightening MoS2 with a record-high enhancement factor of ~440, i.e., two-order-of-magnitude higher than the data reported to date. The polariton relaxation features a short characteristic time of ~1.3 ps, resulting from the significantly enhanced intra- and inter-branch exciton-exciton scattering. The polariton relaxation dynamics is associated with Rabi energies in a phase diagram by combining experimental and theoretical results. This study opens a new direction of microcavity 2D semiconductor heterojunctions for high-brightness polaritonic light sources and ultrafast polariton carrier dynamics.

3.
Nat Commun ; 14(1): 3374, 2023 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-37291124

RESUMEN

The ligand effects of atomically precise metal nanoclusters on electrocatalysis kinetics have been rarely revealed. Herein, we employ atomically precise Au25 nanoclusters with different ligands (i.e., para-mercaptobenzoic acid, 6-mercaptohexanoic acid, and homocysteine) as paradigm electrocatalysts to demonstrate oxygen evolution reaction rate-determining step switching through ligand engineering. Au25 nanoclusters capped by para-mercaptobenzoic acid exhibit a better performance with nearly 4 times higher than that of Au25 NCs capped by other two ligands. We deduce that para-mercaptobenzoic acid with a stronger electron-withdrawing ability establishes more partial positive charges on Au(I) (i.e., active sites) for facilitating feasible adsorption of OH- in alkaline media. X-ray photo-electron spectroscopy and theoretical study indicate a profound electron transfer from Au(I) to para-mercaptobenzoic acid. The Tafel slope and in situ Raman spectroscopy suggest different ligands trigger different rate-determining step for these Au25 nanoclusters. The mechanistic insights reported here can add to the acceptance of atomically precise metal nanoclusters as effective electrocatalysts.


Asunto(s)
Electrones , Metales , Ligandos , Oxidación-Reducción , Transporte de Electrón , Adsorción
4.
Zhongguo Zhong Yao Za Zhi ; 48(9): 2490-2499, 2023 May.
Artículo en Chino | MEDLINE | ID: mdl-37282878

RESUMEN

The effect of Tujia medicine Berberidis Radix on endogenous metabolites in the serum and feces of mice with ulcerative colitis(UC) induced by dextran sulfate sodium(DSS) was analyzed by metabolomics technology to explore the metabolic pathway and underlying mechanism of Berberidis Radix in the intervention of UC. The UC model was induced in mice by DSS. Body weight, disease activity index(DAI), and colon length were recorded. The levels of tumor necrosis factor-α(TNF-α) and interleukin-10(IL-10) in colon tissues were determined by ELISA. The levels of endogenous metabolites in the serum and feces were detected by ultra-high-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry(UPLC-Q-TOF-MS). Principal component analysis(PCA) and orthogonal partial least squares-discriminant analysis(OPLS-DA) were employed to characterize and screen differential metabolites. The potential metabolic pathways were analyzed by MetaboAnalyst 5.0. The results showed that Berberidis Radix could significantly improve the symptoms of UC mice and increase the level of the anti-inflammatory factor IL-10. A total of 56 and 43 differential metabolites were identified in the serum and feces, respectively, belonging to lipids, amino acids, fatty acids, etc. After the intervention by Berberidis Radix, the metabolic disorder gradually recovered. The involved metabolic pathways included biosynthesis of phenylalanine, tyrosine, and tryptophan, linoleic acid metabolism, phenylalanine metabolism, and glycerophospholipid metabolism. Berberidis Radix can alleviate the symptoms of mice with DSS-induced UC, and the mechanism may be closely related to the re-gulation of lipid metabolism, amino acid metabolism, and energy metabolism.


Asunto(s)
Colitis Ulcerosa , Ratones , Animales , Colitis Ulcerosa/inducido químicamente , Colitis Ulcerosa/tratamiento farmacológico , Interleucina-10 , Metabolómica/métodos , Cromatografía Líquida de Alta Presión
5.
Molecules ; 27(12)2022 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-35744927

RESUMEN

Optimal synthesis of distillation sequence is a complex problem in chemical processes engineering, which involves process structure optimization and operation parameters optimization. The study of the synthesis of distillation sequence is a crucial step toward improving the efficiency of chemical processes and reducing greenhouse gas emissions. This work introduced the concept of binary tree to encode the distillation sequence. The performance of the six evolutionary algorithms was evaluated by solving a 14-component distillation sequence synthesis problem. The best algorithm was used to optimize the operation parameters of a triple-column distillation process. The total annual cost and CO2 emissions were considered as the metrics to evaluate the performance of triple-column distillation processes. As a result, NSGA-II-DE was found to be the best one of the six tested evolutionary algorithms. Then, NSGA-II-DE was applied to the distillation sequence optimization to find the best operating parameters, which led to a significant reduction in CO2 emission and total annual costs.


Asunto(s)
Dióxido de Carbono , Destilación , Algoritmos
6.
Micromachines (Basel) ; 13(4)2022 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-35457799

RESUMEN

The dissimilar materials bonding of NiTi alloy with shape memory effect (SME) and CuSn10 alloy with good ductility, electrical conductivity, and thermal conductivity can be used in aerospace, circuits, etc. In order to integrate NiTi and CuSn10 with greatly different physical and chemical properties by selective laser melting (SLM), the effects of forming interlayers with different SLM process parameters were explored in this study. The defects, microstructure, and component diffusion at the interface were also analyzed. Columnar grain was found along the molten pool boundary of the interfacial region, and grains in the interfacial region were refined. Elements in the interfacial region had a good diffusion. Phase identifying of the interface showed that Ni4Ti3 was generated. The analysis showed that the columnar grain, refined grains in the interfacial region, and a certain amount of Ni4Ti3 could strengthen the interfacial bonding. This study provides a theoretical basis for forming NiTi/CuSn10 dissimilar materials structural members.

7.
Chem Biodivers ; 18(11): e2100343, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34460996

RESUMEN

One new siaresinolic acid saponin (1) and three new rotundic acid saponins (2-4) were isolated from the roots of Ilex centrochinensis. Their structures were confirmed by detailed analysis of standard spectroscopic data (IR, MS, 1D and 2D NMR). Compounds 1-4 exhibited anti-inflammatory activity by inhibiting nitric oxide production in a lipopolysaccharide-induced RAW264.7 cell inflammatory model. However, they showed no significant lipid-lowering activity against the production of triglycerides in the lipid-accumulation model of HepG2 cells induced by oleic acid.


Asunto(s)
Antiinflamatorios/farmacología , Ilex/química , Óxido Nítrico/antagonistas & inhibidores , Raíces de Plantas/química , Saponinas/farmacología , Triterpenos/farmacología , Animales , Antiinflamatorios/química , Antiinflamatorios/aislamiento & purificación , Células Hep G2 , Humanos , Lípidos/antagonistas & inhibidores , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Ratones , Óxido Nítrico/biosíntesis , Células RAW 264.7 , Saponinas/química , Saponinas/aislamiento & purificación , Triterpenos/química , Triterpenos/aislamiento & purificación
8.
Nano Lett ; 21(10): 4461-4468, 2021 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-33970625

RESUMEN

Moiré superlattices of van der Waals structures offer a powerful platform for engineering band structure and quantum states. For instance, Moiré superlattices in magic-angle twisted bilayer graphene, ABC trilayer graphene have been shown to harbor correlated insulating and superconducting states, while in transition metal dichalcogenide (TMD) twisted bilayers, Moiré excitons have been identified. Here we show that the effects of a Moiré superlattice on the band structure are general: In TMD twisted bilayers, excitons and exciton complexes can be trapped in the superlattice in a manner analogous to ultracold bosonic or Fermionic atoms in optical lattices. Using twisted MoSe2 homobilayers as a model system, we present evidence for Moiré trions. Our results thus open possibilities for designer van der Waals structures hosting arrays of Fermionic or bosonic quasiparticles, which can be used to realize tunable many-body states crucial for quantum simulation and quantum information processing.

9.
ACS Nano ; 14(10): 13470-13477, 2020 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-32966063

RESUMEN

van der Waals two-dimensional layered heterostructures have recently emerged as a platform, where the interlayer couplings give rise to interesting physics and multifunctionalities in optoelectronics. Such couplings can be rationally controlled by dielectric, separation, and stacking angles, which affect the overall charge or energy-transfer processes, and emergent potential landscape for twistronics. Herein, we report the efficient Förster resonance energy transfer (FRET) in WS2/hBN/MoSe2 heterostructure, probed by both steady-state and time-resolved optical spectroscopy. We clarified the evolution behavior of the electron-hole pairs and free electrons from the trions, that is, ∼59.9% of the electron-hole pairs could transfer into MoSe2 by FRET channels (∼38 ps) while the free electrons accumulate at the WS2/hBN interface to photogate MoSe2. This study presents a clear picture of the FRET process in two-dimensional transition-metal dichalcogenides' heterojunctions, which establishes the scientific foundation for developing the related heterojunction optoelectronic devices.

10.
Psychopharmacology (Berl) ; 237(12): 3591-3602, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32820390

RESUMEN

RATIONALE: Opioids remain the drugs of choice for treating moderate to severe pain, although adverse effects often limit use. Drugs acting concomitantly as agonists at µ opioid receptors and antagonists at δ opioid receptors produce antinociceptive effects with a reduced profile of adverse effects; one such drug, benzylideneoxymorphone (BOM), might further limit adverse effects because it appears to have lower pharmacological efficacy than other µ opioid receptor agonists. OBJECTIVES: The current study compared the acute behavioral effects of BOM with the effects of other µ opioid receptor agonists. METHODS: Discriminative stimulus and rate-decreasing effects were studied in 1 group of 7 rats discriminating 3.2 mg/kg morphine while responding under a fixed-ratio 10 schedule of food presentation. Antinociceptive effects were determined in a second group of 8 rats using a warm water tail withdrawal procedure. Reinforcing effects were evaluated in a third group of 12 rats with a history of remifentanil self-administration. RESULTS: BOM produced morphine-lever responding and both discriminative stimulus and rate-decreasing effects were antagonized by naltrexone. BOM did not markedly increase tail-withdrawal latencies from water maintained at 50 °C and did not substantially attenuate the antinociceptive effects of morphine. BOM was not self-administered and did not change remifentanil self-administration. CONCLUSIONS: Some effects of BOM (e.g., discriminative stimulus effects) appear to be mediated by µ opioid receptors; however, BOM is not self-administered by rats, suggesting that it might have limited abuse liability and a reduced profile of adverse effects compared with currently prescribed opioids.


Asunto(s)
Analgésicos Opioides/farmacología , Oximorfona/análogos & derivados , Dolor/tratamiento farmacológico , Receptores Opioides delta/antagonistas & inhibidores , Receptores Opioides mu/agonistas , Animales , Relación Dosis-Respuesta a Droga , Masculino , Morfina/farmacología , Naltrexona/farmacología , Antagonistas de Narcóticos/farmacología , Oximorfona/farmacología , Dimensión del Dolor/efectos de los fármacos , Ratas , Refuerzo en Psicología , Autoadministración
11.
Nano Lett ; 20(7): 5359-5366, 2020 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-32543201

RESUMEN

Two-dimensional (2D) van der Waals heterostructures have attracted enormous research interests due to their emergent electrical and optical properties. The comprehensive understanding and efficient control of interlayer couplings in such devices are crucial for realizing their functionalities, as well as for improving their performance. Here, we report a successful manipulation of interlayer charge transfer between 2D materials by varying different stacking layers consisting of graphene, hexagonal boron nitride, and tungsten disulfide. Under visible-light excitation, despite being separated by few-layer boron nitride, the graphene and tungsten disulfide exhibit clear modulation of their doping level, i.e., a change of the Fermi level in graphene as large as 120 meV and a net electron accumulation in WS2. By using a combination of micro-Raman and photoluminescence spectroscopy, we demonstrate that the modulation is originated from simultaneous manipulation of charge and/or energy transfer between each of the two adjacent layers.

12.
Chemistry ; 26(29): 6576-6582, 2020 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-31917501

RESUMEN

In this work, a heterostructure obtained by vacuum evaporation of a strong molecular n-dopant, [RuCp*(mes)]2 , onto black phosphorus (BP) is reported, along with the systematic investigation of the interfacial structure and properties by various in situ characterization techniques. Ultraviolet photoelectron spectra (UPS) showed a large decrease in the work function of BP and a new peak within the bandgap, which is attributed to electron transfer from dopants to the underlying BP. The electrons trapped at the interface act as hole traps and induce photogating effect so that a photodetector based on BP-organoruthenium complex heterostructure demonstrates a photoresponsivity of 5.5 mA W-1 and an EQE of 1.3 % at 515 nm, a tenfold improvement compared to the pristine BP device.

13.
Nat Prod Res ; 34(6): 855-858, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30394110

RESUMEN

Epicatechin (EC) is the most effective compound in Euonymus alatus (Thunb.)Sieb, and possesses a series of benefits, including anti-inflammatory, antioxidant, antiobesity and anticancer effects. In this study, we investigated the protective effects of EC in Acetaminophen(N-acetyl-p-aminophenol, APAP)-induced acute liver injury in C57BL/6J mice and explored the possible mechanisms involved in these effects.[Formula: see text].


Asunto(s)
Apoptosis/efectos de los fármacos , Catequina/uso terapéutico , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Inflamación/prevención & control , Acetaminofén/efectos adversos , Animales , Antioxidantes/farmacología , Catequina/farmacología , Inflamación/metabolismo , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Sustancias Protectoras/farmacología , Sustancias Protectoras/uso terapéutico
14.
Nat Prod Res ; 34(19): 2703-2708, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29553829

RESUMEN

A pair of new diastereoisomeric flavan, containing an additional phenylpropanoid (C6-C3) unit in the molecule, has been isolated from the leaves of Ilex centrochinensis. Their structures were identified by extensive spectral analysis and comparison with the data of known analogues.


Asunto(s)
Flavonas/química , Ilex/química , Fenilpropionatos/química , Hojas de la Planta/química , Dicroismo Circular , Espectroscopía de Resonancia Magnética , Estructura Molecular , Propanoles/química , Espectrometría de Masa por Ionización de Electrospray , Estereoisomerismo
15.
Nanoscale ; 11(34): 16122-16129, 2019 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-31433425

RESUMEN

Vapor transportation is the core process in growing transition-metal dichalcogenides (TMDCs) by chemical vapor deposition (CVD). One inevitable problem is the spatial inhomogeneity of vapors. The non-stoichiometric supply of transition-metal precursors and chalcogens leads to poor control in the products' location, morphology, crystallinity, uniformity and batch to batch reproducibility. The vapor-liquid-solid (VLS) growth method often involves molten precursors (e.g., non-volatile Na2MoO4) at growth temperatures higher than their melting points. The liquid Na2MoO4 can precipitate out solid MoS2 monolayers when saturated with sulfur vapor. Taking advantage of the VLS growth, we attained three kinds of important achievements: (i) a 4-inch-wafer-scale uniform growth of MoS2 flakes on SiO2/Si substrates, (ii) a 2-inch-wafer-scale growth of continuous MoS2 film with the grain size exceeding 100 µm on sapphire substrates, and (iii) a patterned (site-controlled) growth of MoS2 flakes and films. We clarified that the VLS growth thus paves a new way for the high-efficient and scalable synthesis of two-dimensional TMDC monolayers.

16.
Nano Lett ; 19(8): 5340-5346, 2019 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-31274321

RESUMEN

Practical applications of two-dimensional (2D) black phosphorus (BP) are limited by its fast degradation under ambient conditions, for which many different mechanisms have been proposed; however, an atomic level understanding of the degradation process is still hindered by the absence of bottom-up methods for the growth of large-scale few-layer black phosphorus. Recent experimental success in the fabrication of single-layer blue phosphorus provides a model system to probe the oxidation mechanism of two-dimensional (2D) phosphorene down to single-layer thicknesses. Here, we report an atomic-scale investigation of the interaction between molecular oxygen and blue phosphorus. The atomic structure of blue phosphorus and the local binding sites of oxygen have been precisely identified using qPlus-based noncontact atomic force microscopy. A combination of low-temperature scanning tunneling microscopy and X-ray photoelectron spectroscopy measurements reveal a thermally reversible oxidation process of blue phosphorus in a pure oxygen atmosphere. Our study clearly demonstrates the essential role of oxygen in the initial oxidation process, and it sheds further light on the fundamental pathways of the degradation mechanism.

17.
J Asian Nat Prod Res ; 21(1): 86-92, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30973279

RESUMEN

A new para-quinone-type flavan, (2S)-7-methoxy-3',4'-dihydroxy-5,8-quinoflavan (1), together with three known compounds, were isolated from the leaves of Ilex centrochinensis. Their structures were elucidated by detailed spectroscopic analyses for new structure and in comparison with published data for known compounds. Moreover, the new compound was evaluated its cytotoxic and anti-inflammatory activities in vitro on LPS induced RAW 264.7 cells and the results showed that 1 has promising anti-inflammatory activities.


Asunto(s)
Antiinflamatorios/farmacología , Flavonoides/aislamiento & purificación , Ilex/química , Animales , Flavonoides/química , Flavonoides/farmacología , Ratones , Hojas de la Planta/química , Células RAW 264.7
18.
Am J Transl Res ; 11(1): 106-119, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30787972

RESUMEN

This study aimed to investigate the protective effects, effective constituents and preliminary mechanisms of Euonymus alatus on liver fibrosis and screen new high-efficacy drug for fibrosis. 112 male C57BL/6 mice were randomly divided into 14 groups: control group (CG), CCL4 group (CTG), low/medium/high dose of Euonymus alatus ethanol extracts (EAE), catechin (CA), dihydroquercetin (DHQ) and kaempferol (KA) groups. The study lasted for 30 days by injecting CCL4 in peritoneal cavity to make fibrosis model, all mice were sacrificed to observe morphological changes and collagenous fiber by HE and Masson staining, to test liver index, ALT, AST, to measure the expression of α-SMA and collagen I by immunohistochemistry and western blotting, to discuss the pathways of TßR1-Smad2/3 and TNF-α-NF-κB by WB and Elisa; after being evaluated the efficacy, anti-fibrosis drug of highest efficacy was chosen to repeat these indexes in human hepatic stellate cells-LX2. Results showed that EAE/CA/DHQ/KA prevented increases in liver index, ALT, AST, α-SMA, collagen I, TßR1, Smad2/3, TNF-α and p-NF-κB caused by CCL4 in dose-dependence, they also improved the liver morphology, decreased inflammatory cell infiltration and collagenous fiber in dose-dependence, CA' efficacy was best in mice; in LX-2, CA also decreased the expression of α-SMA, collagen I, TGF-ß, Smad2/3. All findings suggested that Euonymus alatus could alleviate liver inflammation and fibrosis by inhibiting TßR1-Smad2/3 and TNF-α-NF-κB pathways, flavonoid were effective constituents and catechin was screened as a new star for its best performance.

19.
Nanoscale ; 10(46): 21575-21603, 2018 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-30457619

RESUMEN

Phosphorus, one of the most abundant elements in the Earth (∼0.1%), has attracted much attention in the last five years since the rediscovery of two-dimensional (2D) black phosphorus (BP) in 2014. The successful scaling down of BP endows this 'old material' with new vitality, resulting from the intriguing semiconducting properties in the atomic scale limit, i.e. layer-dependent bandgap that covers from the visible light to mid-infrared light spectrum as well as hole-dominated ambipolar transport characteristics. Intensive research effort has been devoted to the fabrication, characterization, functionalization and application of BP and other phosphorus allotropes. In this review article, we summarize the fundamental properties and fabrication techniques of BP, with particular emphasis on the recent progress in molecular beam epitaxy growth of 2D phosphorus. Subsequently, we highlight recent progress in BP (opto)electronic device applications achieved via customized manipulation methods, such as interface, defect and bandgap engineering as well as forming Lego-like stacked heterostructures.

20.
Adv Mater ; 30(47): e1802207, 2018 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30101443

RESUMEN

Black phosphorus (BP), first synthesized in 1914 and rediscovered as a new member of the family of 2D materials in 2014, combines many extraordinary properties of graphene and transition-metal dichalcogenides, such as high charge-carrier mobility, and a tunable direct bandgap. In addition, it displays other distinguishing properties, e.g., ambipolar transport and highly anisotropic properties. The successful application of BP in electronic and optoelectronic devices has stimulated significant research interest in other allotropes and alloys of 2D phosphorene, a class of 2D materials consisting of elemental phosphorus. As an atomically thin sheet, the various interfaces presented in 2D phosphorene (substrate/phosphorene, electrode/phosphorene, dielectric/phosphorene, atmosphere/phosphorene) play dominant roles in its bottom-up synthesis, and determine several key characteristics for the devices, such as carrier injection, carrier transport, carrier concentration, and device stability. The rational design/engineering of interfaces provides an effective way to manipulate the growth of 2D phosphorene, and modulate its electronic and optoelectronic properties to realize high-performance multifunctional devices. Here, recent progress of the interface engineering of 2D phosphorene is highlighted, including the epitaxial growth of single-layer blue phosphorus on different substrates, surface functionalization of BP for high-performance complementary devices, and the investigation of the BP degradation mechanism in ambient air.

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