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1.
EMBO Rep ; 23(11): e54686, 2022 11 07.
Artigo em Inglês | MEDLINE | ID: mdl-36094741

RESUMO

N6-methyladenosine (m6 A) and alternative polyadenylation (APA) are important regulators of gene expression in eukaryotes. Recently, it was found that m6 A is closely related to APA. However, the molecular mechanism of this new APA regulation remains elusive. Here, we show that YTHDC1, a nuclear m6 A reader, can suppress proximal APA sites and produce longer 3' UTR transcripts by binding to their upstream m6 A sites. YTHDC1 can directly interact with the 3' end processing factor FIP1L1 and interfere with its ability to recruit CPSF4. Binding to the m6 A sites can promote liquid-liquid phase separation of YTHDC1 and FIP1L1, which may play an important role in their interaction and APA regulation. Collectively, YTHDC1 as an m6 A "reader" links m6 A modification with pre-mRNA 3' end processing, providing a new mechanism for APA regulation.


Assuntos
Núcleo Celular , Poliadenilação , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Núcleo Celular/metabolismo , Adenosina/metabolismo , Regiões 3' não Traduzidas
2.
Inorg Chem ; 57(5): 2447-2454, 2018 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-29437388

RESUMO

Temperature plays a crucial role in both scientific research and industry. However, traditional temperature sensors, such as liquid-filled thermometers, thermocouples, and transistors, require contact to obtain heat equilibrium between the probe and the samples during the measurement. In addition, traditional temperature sensors have limitations when being used to detect the temperature change of fast-moving samples at smaller scales. Herein, the carbon quantum dots (C-QDs) functionalized metal-organic framework (MOF) composite film, a novel contactless solid optical thermometer, has been prepared via electrophoretic deposition (EPD). Instead of terephthalic acid (H2BDC), 1',2',4',5'-benzenetetracarboxylic (H4BTEC) acid was employed to construct a UiO-66 framework to present two uncoordinated carboxylic groups decorated on the pore surface. The uncoordinated carboxylic groups can generate negative charges, which facilitates the deposition of film on the positive electrode during the EPD process. Moreover, UiO-66-(COOH)2 MOFs can absorb C-QDs from the solution and prevent C-QDs from aggregating, and the well-dispersed C-QDs impart fluorescence characteristics to composites. As-synthesized composite film was successfully used to detect temperature change in the range of 97-297 K with a relative sensitivity up to 1.3% K-1 at 297 K.

3.
Langmuir ; 33(50): 14238-14243, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29172529

RESUMO

Until now, it has been a challenge to prepare lanthanide metal-organic framework films on traditional substrates, like zinc plate, indium oxide (ITO), and fluorine-doped tin oxide (FTO) glasses in a rapid and facile method. In this paper, continuous and dense Ln-BTC MOFs films on unmodified low-cost substrates have been rapidly and easily fabricated though the newly developed electrophoretic deposition (EPD) method in 5 min. Moreover, the as-prepared luminescent films were successfully used for the detection of nitrobenzene (NB), trinitrotoluene (TNT) in gas phases, as well as NB, Cr3+ ions for detection in solution.

4.
Inorg Chem ; 55(5): 2641-9, 2016 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-26886437

RESUMO

Organic dye pollutants become a big headache due to their toxic nature to the environment, and it should be one of the best solutions if we can separate and reuse them. Here, we report the synthesis and characterization of a microporous anion metal-organic framework (MOF) with Lewis basic sites-rich based on TDPAT (2,4,6-tris(3,5-dicarboxylphenylamino)-1,3,5-triazine) ligand, FJI-C2, which shows high adsorption and separation of cationic dye based on the charge-exclusive effect. Compared to other MOF materials, FJI-C2 shows the largest adsorption amount of methylene blue (1323 mg/g) at room temperature due to the nature of the anion frameworks and high surface area/pore volume. Furthermore, motivated by the adsorption properties of large guest molecules, we proceeded to investigate the catalytic behaviors of FJI-C2, not only because the large pore facilitates the mass transfer of guest molecules but also because the high density of Lewis basic sites can act as effective catalytic sites. As expected, FJI-C2 exhibits excellent catalytic performance for size-selective Knoevenagel condensation under mild conditions and can be reused several times without a significant decrease of the activity.

5.
Small Methods ; : e2401083, 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39194386

RESUMO

Covalent organic frameworks (COFs), with their accessible nanoscale porosity, selectable building blocks, and precisely engineered topology, offer unique benefits in the design of room-temperature phosphorescent (RTP) materials. However, their potential has been limited by phosphorescence quenching caused by interlayer π-π stacking interactions. This paper presents a novel strategy to enhance RTP in heavy-atom-free COFs by employing a donor-acceptor (D-A) system that leverages the Förster resonance energy transfer (FRET) and Dexter energy transfer (DET) mechanisms. Among the materials investigated, the best-performing COF exhibits a phosphorescence lifetime of 4.35 ms at room temperature. Spectral analysis, structural analysis, and theoretical calculations indicate the presence of intralayer FRET processes as well as interlayer DET processes within the D-A COF system. Potential anti-counterfeiting applications are explored by exploiting the unique phosphorescent properties of these materials. Additionally, the inherent permanent porosity of COFs presents new opportunities for future development and application. This strategy offers many promising prospects for advancing the RTP technology in COF materials and broadens their potential applications in various fields.

6.
JACS Au ; 4(7): 2514-2522, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39055143

RESUMO

CO2 electroreduction (CO2RR) to generate valuable chemicals in acidic electrolytes can improve the carbon utilization rate in comparison to that under alkaline conditions. However, the thermodynamically more favorable hydrogen evolution reaction under an acidic electrolyte makes the CO2RR a big challenge. Herein, robust metal phthalocyanine(Pc)-based (M = Ni, Co) conductive metal-covalent organic frameworks (MCOFs) connected by strong metal tetraaza[14]annulene (TAA) linkage, named NiPc-NiTAA and NiPc-CoTAA, are designed and synthesized to apply in the CO2RR in acidic electrolytes for the first time. The optimal NiPc-NiTAA exhibited an excellent Faradaic efficiency (FECO) of 95.1% and a CO partial current density of 143.0 mA cm-2 at -1.5 V versus the reversible hydrogen electrode in an acidic electrolyte, which is 3.1 times that of the corresponding metal-organic framework NiPc-NiN4. The comparison tests and theoretical calculations reveal that in-plane full π-d conjugation MCOF with a good conductivity of 3.01 × 10-4 S m-1 accelerates migration of the electrons. The NiTAA linkage can tune the electron distribution in the d orbit of metal centers, making the d-band center close to the Fermi level and then activating CO2. Thus, the active sites of NiPc and NiTAA collaborate to reduce the *COOH formation energy barrier, favoring CO production in an acid electrolyte. It is a helpful route for designing outstanding conductive MCOF materials to enhance CO2 electrocatalysis under an acidic electrolyte.

7.
Adv Mater ; 36(35): e2313608, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38970535

RESUMO

Metal-organic frameworks (MOFs), characterized by tunable porosity, high surface area, and diverse chemical compositions, offer unique prospects for applications in optoelectronic devices. However, the prevailing research on thin-film devices utilizing MOFs has predominantly focused on aspects such as information storage and photosensitivity, often neglecting the integration of the advantages inherent in both photonics and electronics to enhance optical memory. This work demonstrates a light-mediated resistive memory device based on a highly oriented porphyrin-based MOFs film, in which the resistance state of the memristor is modulated by light, realizing the integration of the perception and storage of optical information. The memristor shows excellent performance with a wide light range of 405-785 nm and a persistent photoconductivity phenomenon up to 8.3 × 103 s. Further mechanistic studies have revealed that the resistive switching effect in the memristor is primarily associated with the reversible formation and annihilation of Ag conductive filaments.

8.
Small Methods ; : e2301807, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38856023

RESUMO

Electrochemical reduction of CO2 to multicarbon (C2+) products with added value represents a promising strategy for achieving a carbon-neutral economy. Precise manipulation of the catalytic interface is imperative to control the catalytic selectivity, particularly toward C2+ products. In this study, a unique Cu/UIO-Br interface is designed, wherein the Cu(111) plane is co-modified simultaneously by Br and O from UIO-66-Br support. Such Cu/UIO-Br catalytic interface demonstrates a superior Faradaic efficiency of ≈53% for C2+ products (ethanol/ethylene) and the C2+ partial current density reached 24.3 mA cm-2 in an H-cell electrolyzer. The kinetic isotopic effect test, in situ attenuated total reflection Fourier transform infrared spectroscopy and density functional theory calculations have been conducted to elucidate the catalytic mechanism. The Br, O co-modification on the Cu(111) interface enhanced the adsorption of CO2 species. The hydrogen-bond effect from the doped Br atom regulated the kinetic processes of *H species in CO2RR and promoted the formation of *COH intermediate. The formed *COH facilitates the *CO-*COH coupling and promotes the C2+ selectivity finally. This comprehensive investigation not only provides an in-depth study and understanding of the catalytic process but also offers a promising strategy for designing efficient Cu-based catalysts with exceptional C2+ products.

9.
Langmuir ; 29(27): 8657-64, 2013 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-23745713

RESUMO

New porous metal-organic framework (MOF) films based on the flexible ligand 1,3,5-tris[4-(carboxyphenyl)oxamethyl]-2,4,6-trimethylbenzene (H3TBTC) were fabricated on α-Al2O3 substrates under solvent thermal conditions. The factors affecting the fabrication of films, such as the temperature of pre-activation and the dosage of the reagents, were investigated. Tuning the subtle factors on film fabrications, a series of MOF thin films with different morphologies and grain sizes were prepared. The morphology and grain size of the films are monitored by scanning electron microscopy (SEM). X-ray diffraction (XRD) and attenuated total reflection infrared (ATR-IR) were also used to characterize the MOF films. The results indicate that the temperature of pre-activation and the dosage of the reagents are the key parameters during the process of film formation. The properties of the films, especially the sensing and sorption behavior, have been studied by an optical digital cameral and ultraviolet-visible (UV-vis) spectra. The evidence shows that the films are sensitive to small organic molecules, such as methanol and pyridine. Meanwhile, the films can adsorb small dye molecules. Thus, the films may have potential applications in either organic vapor sensing or storage of small dye molecules.


Assuntos
Compostos Organometálicos/síntese química , Adsorção , Gases/química , Modelos Moleculares , Estrutura Molecular , Compostos Organometálicos/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície
10.
ACS Appl Mater Interfaces ; 15(30): 36334-36343, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37475107

RESUMO

Halogenated organic compounds are a kind of common environmental pollutants. Photocatalytic dehalogenation of C-halogen (C-X) bonds to C-H bonds can not only control environmental pollution but also realize important organic conversion reactions. However, the electron transfer kinetics of photocatalytic reduction of the C-X bond for semiconductor/MOF composites has remained unexplored. Herein, we successfully synthesized CdS/Zn(impim) (MOF) dots-on-rods composite photocatalyst under mild conditions. Zn(impim) MOF consists of Zn(µ-N)4 clusters and imidazole derivative ligands. Zn(impim), as a carrier, is beneficial to the dispersion of CdS nanoparticles and avoiding the agglomeration of CdS nanoparticles. The photocatalytic performance of CdS/Zn(impim) composites for the reduction of the C-X bond is much higher than that of pure CdS or Zn(impim). This high activity is due to the high electron separation efficiency of CdS assisted by Zn(impim). Under visible light irradiation, Zn(impim) is not excited due to its wide band gap of 3.26 eV. Through metal-to-ligand charge transfer of Zn(µ-N)4 clusters, Zn(impim) accepts excited electrons from CdS because the Fermi energy level of CdS is more negative by Kelvin probe force microscopy. Moreover, fluorescence spectrum and femtosecond transient absorption spectroscopy reveal the related electron transfer kinetics in detail. In addition, the inherent porous structure of MOFs is beneficial to the adsorption of halogenated hydrocarbons, providing a suitable environment for the dehalogenation reaction, thus improving the activity. This work can further understand the electron transfer mechanism in semiconductor/MOF composites for photocatalytic halide dehalogenation.

11.
Adv Mater ; 35(47): e2305344, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37540191

RESUMO

The integration of hydrogen-bonded organic frameworks (HOFs) into electronic devices holds great promise due to their high crystallinity, intrinsic porosity, and easy regeneration. However, despite their potential, the utilization of HOFs in electronic devices remains largely unexplored, primarily due to the challenges associated with fabricating high-quality films. Herein, a controlled synthesis of HOF nanofilms with smooth surface, good crystallinity, and high orientation is achieved using a solution-processed approach. The memristors exhibit outstanding bipolar switching performance with a low set voltage of 0.86 V, excellent retention of 1.64 × 104 s, and operational endurance of 60 cycles. Additionally, these robust memristors display remarkable thermal stability, maintaining their performance even at elevated temperatures of up to 200 °C. More strikingly, scratched HOF films can be readily regenerated through a simple solvent rinsing process, enabling their reuse for the fabrication of new memristors, which is difficult to achieve with traditional resistive switching materials. Additionally, a switching mechanism based on the reversible formation and annihilation of conductive filaments is revealed. This work provides novel and invaluable insights that have a significant impact on advancing the widespread adoption of HOFs as active layers in electronic devices.

12.
Chemistry ; 18(41): 12978-85, 2012 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-22961988

RESUMO

Three sub-10 nm platinum nanoparticles (PtNPs) with distinctive morphologies were developed by using cucurbit[6]uril (CB[6]) as stabilizing agent and support. Both the size and shape of the PtNPs were simultaneously controlled by tuning the reducing agents. The prepared NPs have been comprehensively characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and cyclic voltammetry. On account of the presence of CB[6] and its unique structural features, the as-prepared PtNPs are homogeneous in morphologies and exhibit higher activities toward methanol electrooxidation than commercial Pt/C. CB[6] has the ability to bind small molecules that can promote CO oxidation, therefore, all the three PtNPs showed enhanced poisoning tolerance. Such unique abilities of CB[6] can even promote the poisoning tolerance of commercial Pt/C through simple physical mixing.

13.
Phys Chem Chem Phys ; 14(22): 8051-7, 2012 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-22555145

RESUMO

Aiming at investigating the effect of structure on electrocatalytic properties, Pd(50)Ru(50) nanoparticles (NPs) with three different structures were carefully designed in a one-pot polyol process for application in formic acid electrooxidation. The three structures are: (1) single-phase PdRu nanodendrites (denoted as PR-1), (2) a mixed-phase mixture of PdRu nanodendrites and monometallic Ru NPs (denoted as PR-2), and (3) a mixed-phase mixture of monometallic Pd and Ru NPs (denoted as PR-3). From PR-1 to PR-3, the structure was varied from single-phase to mixed-phase. The relative position of Ru was altered from completely Pd-connected (PR-1), to a mixture of Pd-connected and monometallic (PR-2), and completely monometallic (PR-3). All PdRu NPs outperform the commercial Pd/C. PR-2 exhibits the highest peak current density, but its stability is slightly lower than that of PR-3. When both the current density and the durability are taken into consideration, PR-2 is the best choice of catalyst for formic acid oxidation. It indicates that both the Pd-connected Ru NPs and monometallic Ru NPs in the mixed-phase PR-2 are essential to improve the electrocatalytic properties. Our study also illustrates that the electrochemical active surface area (ECSA) and hydrogen storage capacity of the as-prepared PdRu NPs are greatly enhanced after several hundred scans in formic acid, indicating the possibility for highly restorable catalysts in direct formic acid fuel cells.

14.
Inorg Chem ; 49(2): 736-44, 2010 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-20025263

RESUMO

A series of silver complexes of polyoxometalates (POMs), formulated as, [Ag(2)(4,4'-bpy)(2)(4,4'-Hbpy)(H(2)O)][PW(12)O(40)] (4,4'-bpy = 4,4'-bipyridine, 1), [Ag(4)(4,4'-bpy)(4)][4,4'-H(2)bpy][P(2)W(18)O(62)].4H(2)O (2), [Ag(4)(4,4'-bpy)(4)][H(2)P(2)W(18)O(62)].7H(2)O (3), and Na(8)[Ag(3)(4,4'-bpy)(3)][PW(10)Ag(2)O(39)].6H(2)O (4), have been hydrothermally synthesized in situ at different pH. Complex 1, based on saturated Keggin POM building blocks and silver coordination compounds, exhibits an interesting 3-fold interpenetration of diamondlike network in the POM chemistry. Different from complex 1, complexes 2-3 consist of Wells-Dawson polyoxoanions and silver coordination compounds. Complex 2 represents the highest coordination number of Wells-Dawson polyoxoanions, which helps to form a high-dimensional framework with (4.6(4).8)(4)(4(4).6(16).8(8)) topology. Thee-dimensional (3D) Wells-Dawson phosphotungstate 3 reveals another new topology (4.6(4).7)(4.6(4).8)(2)(4(3).6(8).7(2).8(2)). Complex 4 forms a 3D framework constructed from divacant Keggin polyoxoanions and silver coordination compounds. Their structural differences indicate that the pH value of the reaction system plays a key role on the structures and topologies of these complexes, and the whole self-assembly process is pH-dependent.

15.
J Colloid Interface Sci ; 565: 436-448, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31982710

RESUMO

A novel sandwich-like structure material was exploited for the fabrication of an effective corrosion resistance system. An environmentally friendly composite material was synthesized by installing 8-hydroxyquinoline (8-HQ) on the surface of graphene oxide (GO). In order to prevent leakage of corrosion inhibitor 8-HQ, GO/8-HQ was modified by polydopamine (PDA), denoted as GO/8-HQ/PDA. A sandwich-like structure (GO/8-HQ/PDA) enables long-term stable storage of corrosion inhibitor in the protective matrix. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were utilized to verify the sandwich-like structure of GO/8-HQ/PDA. The electrochemical tests in a 3.5 wt% NaCl solution showed that the addition of well-dispersed GO/8-HQ/PDA into epoxy system (GO/8-HQ/PDA-EP) remarkably improved corrosion protection of AZ31b magnesium alloy compared with pure epoxy (EP) coating. The sandwich structure protects the activity and structural integrity of the corrosion inhibitor (8-HQ). The corrosion inhibitor (8-HQ) of the GO/8-HQ/PDA sandwich structure cuts off the ion exchange between the metal alloy and the electrolyte solution, which hinders the electrochemical corrosion of the metal. A possible corrosion resistance mechanism of GO/8-HQ/PDA is fully discussed. This study provides feasibilities for the immobilization of corrosion inhibitors on the metal surface.

16.
J Colloid Interface Sci ; 579: 842-852, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32679381

RESUMO

The metal corrosion possesses a serious threat to the safety and loss of property. The anticorrosion study on metal-organic frameworks (MOFs) remains rarely reported. Therefore, it is desirable to build MOFs-based anticorrosion coating with long-term corrosion resistance. Herein, we prepared a novel MOF-polymer anticorrosion composite PANI@MIL-101 by encapsulating polyaniline (PANI) within the pores of MIL-101 with in-situ polymerization of aniline monomer. The N2 adsorption-desorption and transmission electron microscopy (TEM) of PANI@MIL-101 illustrate that PANI is successfully encapsulated in the pores of MIL-101 with in-situ polymerization. PANI@MIL-101 was dispersed in epoxy resin (EP) to prepare anti-corrosive coatings. The Tafel potentiodynamic polarization measurements and electrochemical impedance spectroscopy show that PANI@MIL-101/EP coating system has superior corrosion protection with the lowest icorr value and the highest |Z|0.01 value compared with MIL-101/EP coating, PANI/EP coating and EP coating. A possible anticorrosion mechanism of PANI@MIL-101 was discussed. This work reveals that MOF-polymer composite materials are superb candidates for high-performance corrosion protection.

17.
Inorg Chem ; 47(13): 5612-5, 2008 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-18533627

RESUMO

A novel pentadecatungstate, [H 6Ce 2(H 2O)Cl(W 5O 18) 3] (7-) ( 1), constructed by a dinuclear cerium unit and 15-member ring WO 6 units was prepared and characterized by single-crystal X-ray diffraction. Polyanion 1 exhibits blue photoluminescence with an emission maximum at 488 nm, which is characteristic of cerium(III) transitions from 5d to (2)F 5/2 states. Furthermore, the study of the electrochemical property investigation of 1 shows two reversible redox peaks ascribing to two-electron processes.


Assuntos
Cério/química , Compostos Organometálicos/síntese química , Compostos de Tungstênio/química , Cristalização , Luminescência , Oxirredução , Difração de Raios X
18.
ACS Appl Mater Interfaces ; 10(24): 20854-20861, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-29846055

RESUMO

A novel dual-emitting metal-organic framework based on Zr and Eu, named as UiO-66(Zr&Eu), was built using a clever strategy based on secondary building units. With the use of polymers, the obtained UiO-66(Zr&Eu) was subsequently deposited as thin films that can be utilized as smart thermometers. The UiO-66(Zr&Eu) polymer films can be used for the detection of temperature changes in the range of 237-337 K due to the energy transfer between the lanthanide ions (Eu in clusters) and the luminescent ligands, and the relative sensitivity reaches 4.26% K-1 at 337 K. Moreover, the sensitivity can be improved to 19.67% K-1 by changing the film thickness. In addition, the temperature-sensing performance of the films is superior to that of the powders, and the sensor can be reused 3 times without loss of performance.

19.
ACS Appl Mater Interfaces ; 10(6): 6014-6023, 2018 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-29359915

RESUMO

Engineering novel dual-emitting metal-organic frameworks (MOFs) with wide emission ranges for application as ratiometric temperature sensors is still a challenge. In this paper, two novel dual-emitting MOFs with intergrated lanthanide metals and luminescent ligand in a UiO-66-type structure, named Ln@UiO-66-Hybrid, were prepared via the combination of postsynthetic modification and postsynthetic exchange methods. Subsequently, the as-synthesized MOFs were deposited onto fluorine tin oxide substrates through electrophoretic deposition by taking advantage of the charges from the unmodified carboxylic groups of the MOFs. The as-prepared Tb@UiO-66-Hybrid and Eu@UiO-66-Hybrid films were applied to detect temperature changes. The resulting Tb@UiO-66-Hybrid film exhibited good temperature-sensing properties with a relative sensitivity of up to 2.76% K-1 in the temperature range of 303-353 K. In addition, the Eu@UiO-66-Hybrid film showed excellent temperature-sensing performance based on the energy transfer between the luminescent ligand (H2NDC) and europium ions with a relative sensitivity of up to 4.26% K-1 in the temperature range of 303-403 K.

20.
Chem Commun (Camb) ; (18): 1813-5, 2007 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-17476396

RESUMO

Multilayer films composed of single-component and positively-charged tetraaminocalix[4]arenes are formed through hydrogen bonding.

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