Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
RSC Adv ; 13(19): 13177-13182, 2023 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-37124008

RESUMEN

Tungsten oxide is regarded as the most promising electrochromic material owing to its continuously tunable optical properties, low cost, and high coloration efficiency. Further improving its optical modulation, switching speed, and coloration efficiency is important to electrochromic smart windows and related devices. Here, we demonstrate an enhanced electrochromic film composed of a WO3 nanosheet and ITO nanoparticles developed by an all-solution technology. The WO3 nanosheet is fabricated by an acid-assisted hydrothermal process with high product efficiency. The introduction of an ITO into the WO3 nanosheets significantly improved the electrochemical activity and the conductivity of the composite film. Compared with a reported electrochromic film without ITO doping, our synthesized composite WO3 film exhibited optical modulation up to 88% and a high coloration efficiency of 154.16 cm2 C-1. Particularly, our electrochromic film was based on the dispersant solution and spin-coating technology, which may also be realized with nano-spray coating for large scale applications. The results offer an effective way to develop large-area electrochromic film and devices.

2.
Opt Lett ; 48(3): 644-647, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36723553

RESUMEN

In this Letter, we theoretically study the topological plasmons in Su-Schrieffer-Heeger (SSH) model-based graphene nanoribbon (GNR) layers. We find that for the one-dimensional (1D) stacked case, only two topological modes with the field localized in the top or bottom layer are predicted to exist by the Zak phase. When we further expand the stacked 1D GNR layers to two-dimensional (2D) arrays in the in-plane direction, the topology is then characterized by the 2D Zak phase, which predicts the emergence of three kinds of topological modes: topological edge, surface, and corner modes. For a 2D ribbon array with Nx × Ny units, there are 4(Ny - 1), 4(Nx - 1), and 4 topological edge, surface, and corner modes, and the field is highly localized at the edge/surface/corner ribbons. This work offers a platform to realize topological modes in GNRs and could be important for the design of topological photonic devices such as lasers and sensors.

3.
ACS Appl Mater Interfaces ; 15(9): 12109-12118, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36813758

RESUMEN

The charge transfer between the donor and acceptor determines the photogenerated carrier density in organic solar cells. However, a fundamental understanding regarding the charge transfer at donor/acceptor interfaces with high-density traps has not been fully addressed. Herein, a general correlation between trap densities and charge transfer dynamics is established by adopting a series of high-efficiency organic photovoltaic blends. It is found that the electron transfer rates are reduced with increased trap densities, while the hole transfer rates are independent of trap states. The local charges captured by traps can induce potential barrier formation around recombination centers, leading to the suppression of electron transfer. For the hole transfer process, the thermal energy provides a sufficient driving force, which ensures an efficient transfer rate. As a result, a 17.18% efficiency is obtained for PM6:BTP-eC9-based devices with the lowest interfacial trap densities. This work highlights the importance of interfacial traps in charge transfer processes and proposes an underlying insight into the charge transfer mechanism at nonideal interfaces in organic heterostructures.

5.
Arab J Gastroenterol ; 23(1): 20-25, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-35153173

RESUMEN

BACKGROUND AND STUDY AIMS: This study aims to assess the value of endoscopic ultrasound (EUS) for acquiring a pathological diagnosis of gastrointestinal lymphoma (GIL). PATIENTS AND METHODS: We retrospectively reviewed all GIL patients who underwent EUS from November 2011 to July 2020 at Fudan University Shanghai Cancer Center. All patients with pathologically confirmed GIL were included. The characteristics of the lesions were recorded, and the efficacy for acquiring pathologic diagnosis between white light endoscopy (WLE) and EUS was analyzed. RESULTS: In total, 404 patients with GIL who underwent EUS examination were included in this study. GIL was confirmed in 143 cases by after EUS judgment biopsy (AEJ biopsy), 11 cases by endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA), 293 cases by WLE biopsy, and 10 cases by surgical pathology for repeated negative pathologic results from EUS and WLE. Among all cases, 78.71% (318/404) were T1-T2, whereas 32.18% (130/404) were determined to have multiple lesions in the digestive tract wall. The positive rates of the WLE biopsy and AEJ biopsy of the involved gastric wall were 77.93% (293/376) and 89.38% (143/160), respectively. Twelve cases showed diffuse thickening of the gastric wall, and the total positive rate of EUS was 91.67% but 0% for WLE with this type of GIL. The total positive rate and positive rate during the first examination of EUS were all significantly higher than those of WLE. Moreover, 19.68% of the patients showed negative results during their WLE examination and then received a positive pathologic diagnosis upon EUS examination, but none had the opposite process. CONCLUSIONS: EUS was found to be a better tool for acquiring a pathological diagnosis of GIL than conventional WLE, especially for GIL similar to linitis plastica.


Asunto(s)
Linitis Plástica , Linfoma , Neoplasias Gástricas , China , Humanos , Linfoma/diagnóstico por imagen , Estudios Retrospectivos , Neoplasias Gástricas/patología
6.
Adipocyte ; 10(1): 658-669, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34872433

RESUMEN

Important candidate genes that regulate lipid metabolism have the potential to increase the content of intramuscular fat (IMF) and improve meat quality. Secreted protein acidic and rich in cysteine like 1(SPARCL1) is a secreted glycoprotein with important physiological functions and is involved in the proliferation and differentiation of various cells. However, the role of the SPARCL1 gene in sheep preadipocytes and its regulatory mechanism is still unclear. In this study, we explored the effect of SPARCL1 on the proliferation and differentiation of sheep preadipocytes. The results showed that the expression level of the SPARCL1 gene is higher in fat tissue than in other tissues, and the gene was significantly increased on the 6th day of preadipocyte differentiation. In the preadipocyte proliferation stage, interference of SPARCL1 gene reduced cell viability and increased cell apoptosis. In preadipocyte differentiation stage, SPARCL1 overexpression significantly inhibited lipid droplets accumulation and triglyceride content by increasing Wnt10b, Fzd8, IL6, and ß-catenin and inhibiting PPARγ, C/EBPα, LPL, and IGF1 genes expression, whereas SPARCL1 deficiency significantly promoted cell differentiation by inhibiting ß-catenin and increasing GSK3ß, PPARγ, C/EBPα, and LPL. The results of this study suggest that SPARCL1 plays a negative role during preadipocyte differentiation and may become a novel target for regulating preadipocyte differentiation and improving IMF.Abbreviations:IMF: Intramuscular fat SPARCL1: Secreted protein acidic and rich in cysteine like 1 PPARγ: Peroxisome proliferator-activated receptor γ C/EBPα: CCAAT/enhancer-binding protein-α LPL: Lipoprotein lipase IGF1: Insulin-like growth factor 1 Wnt10b: Wnt family member 10B Fzd8: Frizzled class receptor 8 IL6: Interleukin 6 ß-catenin: Catenin beta interacting protein 1 GSK3ß: Glycogen synthase kinase 3 beta LRP5/6: Low-density lipoprotein receptor-related protein 5/6.


Asunto(s)
Adipocitos , Proteínas de Unión al Calcio/metabolismo , Proliferación Celular , Proteínas de la Matriz Extracelular/metabolismo , Adipocitos/citología , Adipogénesis , Animales , Proteína alfa Potenciadora de Unión a CCAAT/metabolismo , Diferenciación Celular , Ovinos
7.
Front Genet ; 12: 662143, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34394181

RESUMEN

Many local sheep breeds in China have poor meat quality. Increasing intramuscular fat (IMF) content can significantly improve the quality of mutton. However, the molecular mechanisms of intramuscular adipocyte formation and differentiation remain unclear. This study compared differences between preadipocytes and mature adipocytes by whole-transcriptome sequencing and constructed systematically regulatory networks according to the relationship predicted among the differentially expressed RNAs (DERs). Sequencing results showed that in this process, there were 1,196, 754, 100, and 17 differentially expressed messenger RNAs (mRNAs), long non-coding RNAs (lncRNAs), microRNAs (miRNAs), and circular RNAs (circRNAs), respectively. Gene Ontology analysis showed that most DERs enriched in Cell Part, Cellular Process, Biological Regulation, and Binding terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis found that the DERs primarily focused on Focal adhesion, phosphoinositide 3-kinase (PI3K)-Akt, mitogen-activated protein kinase (MAPK), peroxisome proliferator-activated receptor (PPAR) signaling pathways. Forty (40) DERs were randomly selected from the core regulatory network to verify the accuracy of the sequence data. The results of qPCR showed that the DER expression trend was consistent with sequence data. Four novel promising candidate miRNAs (miR-336, miR-422, miR-578, and miR-722) played crucial roles in adipocyte differentiation, and they also participated in multiple and important regulatory networks. We verified the expression pattern of the miRNAs and related pathways' members at five time points in the adipocyte differentiation process (0, 2, 4, 6, 8, 10 days) by qPCR, including miR-336/ACSL4/LncRNA-MSTRG71379/circRNA0002331, miR-422/FOXO4/LncRNA-MSTRG54995/circRNA0000520, miR-578/IGF1/LncRNA-MSTRG102235/circRNA0002971, and miR-722/PDK4/LncRNA-MSTRG107440/circ RNA0002909. In this study, our data provided plenty of valuable candidate DERs and regulatory networks for researching the molecular mechanisms of sheep adipocyte differentiation and will assist studies in improving the IMF.

8.
ACS Appl Mater Interfaces ; 13(9): 11134-11143, 2021 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-33625840

RESUMEN

Achieving high-efficiency thick-film bulk heterojunction (BHJ) organic solar cells (OSCs) with thickness-independent power conversion efficiencies (PCEs) in a wide thickness range is still a challenge for the roll-to-roll printing techniques. The concept of diluting the transport sites within BHJ films with insulating polymers can effectively eliminate charge trapping states and optimize the charge transport. Herein, we first adopted the concept with insulating polypropylene (PP) in the efficient non-fullerene system (PM6:Y6) and demonstrated its potential to fabricate thick-film OSCs. The PP can form an insulating matrix prior to PM6 and Y6 within the BHJ film, resulting in an enhanced molecular interaction and isolated charge transport by expelling Y6 molecules. We thus observed reduced trap state density and improved charge transport properties in the PP-blended device. At around 300 nm, the PM6:Y6:PP device enjoys a high PCE of 15.5% and achieves over 100% of the efficiency of the optimal thin-film device, which is significantly improved compared to the binary PM6:Y6 counterpart. This research promotes an effective strategy with insulating polymers and provides knowledge of commercial production with response to the roll-to-roll technique demands.

10.
Dalton Trans ; 46(44): 15178-15180, 2017 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-29067379

RESUMEN

An unusual Cu(ii) coordination polymer [Cu(Him)2(L)] (1) having a 4,4'-{[1,2-phenylene bis-(methylene)]bis(oxy)}dibenzoic acid ligand and an imidazole ligand possessing a 1D zig-zag chain was constructed and its magnetic behaviour was investigated, which indicated a magnetic phase transition below 25 K as well as long-range magnetic ordering.

11.
Opt Lett ; 42(15): 3052-3055, 2017 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-28957243

RESUMEN

We propose to achieve multi-band perfect plasmonic absorptions with peak absorptivity >99% via the excitation of standing-wave graphene surface plasmon polaritons using single-layer graphene-based rectangular gratings. For the case with continuous gratings, perfect absorptions are only allowed for even-order modes, while the absorptions are quite low for odd-order modes because the fields are out-of-phase. However, for gratings with bottom-open configuration, four-band perfect absorptions containing both the even- and odd-order modes can be realized, which are found to be highly sensitive to the incident angle. The simulated results agree very well with the theoretical analyses by considering the phase path of the plasmonic waves. This multi-band absorber is a promising candidate for future plasmonic devices.

12.
Opt Express ; 24(16): 17886-99, 2016 Aug 08.
Artículo en Inglés | MEDLINE | ID: mdl-27505756

RESUMEN

To achieve plasmonically induced transparency (PIT), general near-field plasmonic systems based on couplings between localized plasmon resonances of nanostructures rely heavily on the well-designed interantenna separations. However, the implementation of such devices and techniques encounters great difficulties mainly to due to very small sized dimensions of the nanostructures and gaps between them. Here, we propose and numerically demonstrate that PIT can be achieved by using two graphene layers that are composed of a upper sinusoidally curved layer and a lower planar layer, avoiding any pattern of the graphene sheets. Both the analytical fitting and the Akaike Information Criterion (AIC) method are employed efficiently to distinguish the induced window, which is found to be more likely caused by Autler-Townes splitting (ATS) instead of electromagnetically induced transparency (EIT). Besides, our results show that the resonant modes cannot only be tuned dramatically by geometrically changing the grating amplitude and the interlayer spacing, but also by dynamically varying the Fermi energy of the graphene sheets. Potential applications of the proposed system could be expected on various photonic functional devices, including optical switches, plasmonic sensors.

13.
Chempluschem ; 81(12): 1299-1304, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31964061

RESUMEN

Luminescent metal-organic frameworks (LMOFs) containing fluorescent probes for the detection of pollutants such as organic solvents and heavy metals are becoming increasingly important, with lanthanide-MOF (Ln-MOF) materials receiving greater attention owing to the possibility of achieving fine-tuned luminescent properties. Herein, two unusual isostructural nanocage-based three-dimensional Ln-MOFs, 1-Ln (Ln=Tb, Eu), are constructed, using a new diisophthalate ligand with active Lewis basic triazole sites. Selective gas adsorption, especially the removal of CO2 from CH4 , a primary component of natural gas and biogas, is desirable in terms of both economic and environmental considerations. 1-Eu is found to exhibit highly efficient luminescent sensing for Fe3+ cations and Cr2 O7 2- anions, as well as selective CO2 capture over CH4 .

14.
Chempluschem ; 81(8): 885-892, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31968818

RESUMEN

A new ZnII metal-organic framework, [Zn6 (L)3 (DMA)4 ]⋅5 DMA (H4 L=[1,1':3',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid, DMA=dimethylacetamide), has been synthesized and characterized. The structure contains a three-dimensional 3,4,4,6-connected net with (4.62 )2 (66 )(66 )(42 .610 .83 ) topology and displays selective detection of nitrobenzene, CrO4 2- and Fe3+ ions. The present work thus indicates that this metal-organic framework could be a prospective candidate for developing novel luminescence sensors for the selective sensing of nitrobenzene, which can be used as a precursor for explosives. Furthermore, the photoluminescent properties of this material in different solvents and with various analytes were investigated and corroborated by theoretical calculations. The results were in good agreement with the experimental solvent-dependent luminescence behavior.

15.
Oncol Lett ; 10(3): 1481-1486, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26622695

RESUMEN

The present study aimed to investigate the association between five common small nucleotide polymorphisms (SNPs) in the VEGF gene and the risk of osteosarcoma. An additional aim was to investigate the role of these five SNPs on the prognosis of osteosarcoma. A total of 186 patients with osteosarcoma and 186 age- and sex-matched healthy controls were enrolled into the present study. A polymerase chain reaction-restriction fragment length polymorphism assay was conducted to determine the incidence of the VEGF-2578 C/A, -1156 G/A, +1612 G/A, +936 C/T and -634 G/C polymorphisms. Conditional logistic regression analyses revealed that individuals carrying the -634 GG genotype possessed a significantly increased risk of osteosarcoma, with an adjusted odds ratio [(95% confidence interval (CI)] of 2.00 (1.07-3.75). In the Cox proportional hazards model, subsequent to adjusting for potential confounding factors, patients with osteosarcoma carrying the -634 GG genotype were found to demonstrate a shorter overall survival time (hazard ratio, 3.10; 95% CI, 1.17-8.38). The VEGF-634 G/C polymorphism may therefore be used as a genetic marker for the prediction of the risk and clinical outcome of osteosarcoma.

16.
Dalton Trans ; 44(44): 19370-82, 2015 11 28.
Artículo en Inglés | MEDLINE | ID: mdl-26501793

RESUMEN

Three new metal organic frameworks (MOFs) with chemical formulae [(CH3)2NH2] [Sm3(L1)2(HCOO)2(DMF)2(H2O)]·2DMF·18H2O (1), [Cu2(L2)(H2O)2]·2.22DMA (2) and [Zn2(L1)(DMA)]·1.75DMA were synthesized and structurally characterized. 1 and 2 show a classical NbO-like topology and have two types of interconnected cages. 3 exhibits an uncommon zzz topology and has two types of interconnected cages. These MOFs can adsorb large amounts of the drug 5-fluorouracil (5-FU) and release it in a progressive way. 5-FU was incorporated into desolvated 1, 2 and 3 with loadings of 0.40, 0.42, and 0.45 g g(-1), respectively. The drug release rates were 72%, 96% and 79% of the drug after 96 hours in 1, 120 hours in 2 and 96 hours in 3, respectively. Grand Canonical Monte Carlo (GCMC) simulations were performed to investigate the molecular interactions during 5-FU adsorption to the three novel materials. The GCMC simulations reproduced the experimental trend with respect to the drug loading capacity of each material. They also provided a structural description of drug packing within the frameworks, helping to explain the load capacity and controlled release characteristics of the materials. 5-FU binding preferences to 1, 2 and 3 reflect the diversity in pore types, chemistry and sizes. The calculated drug load is more related to the molecular properties of accessible volume Vacc than to the pore size.


Asunto(s)
Sistemas de Liberación de Medicamentos , Nanopartículas/química , Compuestos Organometálicos/síntesis química , Compuestos Organometálicos/farmacología , Adsorción , Antimetabolitos Antineoplásicos/administración & dosificación , Antimetabolitos Antineoplásicos/química , Simulación por Computador , Cristalografía por Rayos X , Fluorouracilo/administración & dosificación , Fluorouracilo/química , Cromatografía de Gases y Espectrometría de Masas , Modelos Moleculares , Método de Montecarlo
17.
Inorg Chem ; 54(14): 6719-26, 2015 Jul 20.
Artículo en Inglés | MEDLINE | ID: mdl-26146847

RESUMEN

By using a strategy of introducing hydrophobic groups to the linkers, a hydrostable MOF was constructed based on 5-nitroisophthalate and 2,2'-dimethyl-4,4'-bipyridine coligands, revealing a 3D dia topology structure with a 1D channel parallel to the c axis. TGA, PXRD, and water vapor sorption results show high thermal and water stability for the framework. The framework is very porous and possesses not only high busulfan payloads with an encapsulation efficiency up to 21.5% (17.2 wt %) but also very high CO2 selective capture compared with that of other small gases (i.e., CH4, N2, O2, CO, and H2) at 298 K based on molecular simulations due to the pore surface being populated by methyl and nitryl groups. Furthermore, in vitro MTT assays were conducted on four different cells lines with increasing concentrations of the framework, and the results showed that the framework was nontoxic (cell viability >80%) in spite of the concentrations up to 500 µg/mL.


Asunto(s)
Dióxido de Carbono/aislamiento & purificación , Portadores de Fármacos/química , Nitritos/química , Compuestos Organometálicos/química , Ácidos Ftálicos/química , Piridinas/química , Adsorción , Animales , Antineoplásicos Alquilantes/administración & dosificación , Busulfano/administración & dosificación , Supervivencia Celular , Cristalografía por Rayos X , Portadores de Fármacos/toxicidad , Humanos , Ratones , Modelos Moleculares , Nitritos/toxicidad , Compuestos Organometálicos/toxicidad , Ácidos Ftálicos/toxicidad , Porosidad , Piridinas/toxicidad
18.
Opt Express ; 23(10): 12524-32, 2015 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-26074507

RESUMEN

We numerically demonstrate dynamically tuneable plasmon-induced transparency in a π-shaped metamolecules made of graphene nanostrips by applying external static magnetic field. It is shown that for graphene nanostrips with appropriate Fermi energy, the resonant wavelength, line-shape, and the polarization of transmitted light in the mid-infrared can be effectively controlled by magnetic field. In particular, giant polarization rotation exceeding 20° has been observed in asymmetric graphene metamolecules, which is further enhanced to almost 40° due the Faraday effect in the applied magnetic field, at around 9 µm wavelength, much higher frequency than the Faraday rotation observed in a semi-infinite graphene microribbons. The results offer a flexible approach for the development of compact, tunable graphene-based photonic devices.

19.
Dalton Trans ; 43(46): 17265-73, 2014 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-25310496

RESUMEN

Two isoreticular metal-organic frameworks with chemical formulae [Cu(L)(4,4'-bipy)(H2O)]n 1.5nCH3CN (1) and [Cu(L)(4,4'-bipy)(H2O)]n·4nH2O (2) (H2L = diphenylmethane-4,4'-dicarboxylic acid) were synthesized and structurally characterized. They show the CdSO4 (6(5) 8) net and have an obvious 1D channel that is spread along the crystallographic c axis. More importantly, 1 shows high selectivity for H2 over N2 and CO2 at low pressure, which could be confirmed via computational calculations using the Connolly algorithm to reveal the size and shape of accessible voids. The incorporation of the drug 5-fluorouracil (5-FU) into the desolvated 1 was around 27.5 wt% per gram of the dehydrated 1. 5-FU is released in a highly controlled and progressive fashion with 61% of the drug released after 95 hours. In addition, we have applied molecular docking calculations to investigate the preferred conformation of 5-FU molecules upon binding to MOF 1. These calculations provide a structural basis to explain the 5-FU release from MOF 1.


Asunto(s)
Compuestos de Cadmio/química , Simulación por Computador , Sistemas de Liberación de Medicamentos , Compuestos Organometálicos/química , Sulfatos/química , Adsorción , Cristalografía por Rayos X , Gases/química , Modelos Moleculares , Estereoisomerismo
20.
Opt Express ; 22(6): 6680-90, 2014 Mar 24.
Artículo en Inglés | MEDLINE | ID: mdl-24664017

RESUMEN

We find that a stacked pair of graphene ribbon arrays with a lateral displacement can excite plasmon waveguide mode in the gap between ribbons, as well as surface plasmon mode on graphene ribbon surface. When the resonance wavelengthes of plasmon waveguide mode and surface plasmon mode are close to each other, there is a strong electromagnetic interaction between the two modes, and then they contribute together to transmission dip. The plasmon waveguide mode resonance can be manipulated by the lateral displacement and longitudinal interval between arrays due to their influence on the manner and strength of electromagnetic coupling between two arrays. The findings expand our understanding of electromagnetic resonances in graphene-ribbon array structure and may affect further engineering of nanoplasmonic devices and metamaterials.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...