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1.
Chemphyschem ; : e202400133, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38624189

RESUMO

Electrochemistry-based light-emitting devices have gained considerable attention in different applications such as sensing and optical imaging. In particular, such systems are an interesting alternative for the development of multimodal light-emitting platforms. Herein we designed a multicolor light-emitting array, based on the electrochemical switch-on of light-emitting diodes (LEDs) with a different intrinsic threshold voltage. Thermodynamically and kinetically favored coupled redox reactions, i.e. the oxidation of Mg and the reduction of protons on Pt, act as driving force to power the diodes. Moreover, this system enables to trigger an additional light emission based on the interfacial reductive-oxidative electrochemiluminescence (ECL) mechanism of the Ru(bpy)32+/S2O82- system. The synergy between these light-emission pathways offers a multimodal platform for the straightforward optical readout of physico-chemical information based on composition changes of the solution.

2.
Chemistry ; : e202400078, 2024 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-38470292

RESUMO

Water splitting has become a sustainable and clean alternative for hydrogen production. Commonly, the efficiency of such reactions is intimately related to the physico-chemical properties of the catalysts that constitute the electrolyzer. Thus, the development of simple and fast methods to evaluate the electrocatalytic efficiency of an electrolyzer is highly required. In this work, we present an unconventional method based on the combination of bipolar electrochemistry and light-emitting diodes, which allows the evaluation of the electrocatalytic performance of the two types of catalysts, composing an electrolyzer, namely for oxygen and hydrogen evolution reactions, respectively. The integrated light emission of the diode acts as an optical readout of the electrocatalytic information, which simultaneously depends on the composition of the anode and the cathode. The electrocatalytic activity of Au, Pt, and Ni electrodes, connected to the LED in multiple anode/cathode configurations, towards the water splitting reactions has been evaluated. The efficiency of the electrolyzer can be represented in terms of the onset electric field (ϵonset) for light emission, obtaining variations that are in agreement with data reported with conventional electrochemistry. This work introduces a straightforward method for evaluating electrocatalysts and underscores the importance of material characterization in developing efficient electrolyzers for hydrogen production.

3.
Int J Cancer ; 154(12): 2106-2120, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38353495

RESUMO

Mutations in histone H3.3-encoding genes causing mutant histone tails are associated with specific cancers such as pediatric glioblastomas (H3.3-G34R/V) and giant cell tumor of the bone (H3.3-G34W). The mechanisms by which these mutations promote malignancy are not completely understood. Here we show that cells expressing H3.3-G34W exhibit DNA double-strand breaks (DSBs) repair defects and increased cellular sensitivity to ionizing radiation (IR). Mechanistically, H3.3-G34W can be deposited to damaged chromatin, but in contrast to wild-type H3.3, does not interact with non-homologous end-joining (NHEJ) key effectors KU70/80 and XRCC4 leading to NHEJ deficiency. Together with defective cell cycle checkpoints reported previously, this DNA repair deficiency in H3.3-G34W cells led to accumulation of micronuclei and cytosolic DNA following IR, which subsequently led to activation of the cyclic GMP-AMP synthase/stimulator of interferon genes (cGAS/STING) pathway, thereby inducing release of immune-stimulatory cytokines. These findings suggest a potential for radiotherapy for tumors expressing H3.3-G34W, which can be further improved by combination with STING agonists to induce immune-mediated therapeutic efficacy.


Assuntos
Distúrbios no Reparo do DNA , Histonas , Criança , Humanos , Histonas/genética , Nucleotidiltransferases/genética , Imunidade , DNA
4.
Chem ; 10(2): 660-674, 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38344168

RESUMO

Chirality plays a crucial role in different research fields, ranging from fundamental physico-chemistry to applied aspects in materials science and medicine. In this context, enantioselective loading and pumping of chiral analytes for analysis, separation, and cargo delivery applications is an interesting scientific challenge. Herein, we introduce artificial chiral soft electromechanical pumps based on a bi-layer film built up by electrodepositing polypyrrole and an inherently chiral conducting oligomer at its internal surface. The enantioselective device can be driven by bipolar electrochemistry to act as a pump, allowing the selective loading and separation of different chiral analytes injected as pure enantiomers and in racemic form (i.e., doxorubicin, a chemotherapy drug, limonene, carvone, and a chiral ferrocene). The synergy between wireless electromechanical actuation and inherent enantiodiscrimination features makes these actuators excellent candidates for the controlled handling of chiral molecules in the frame of potential applications ranging from analysis to drug delivery.

5.
ChemMedChem ; 19(7): e202300557, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38233349

RESUMO

The development of new pharmaceutical compounds is challenging because most of them are based on enantiopure chiral molecules, which exhibit unique properties for therapy. However, the synthesis of pharmaceutical compounds in the absence of a chiral environment naturally leads to a racemic mixture. Thus, to control their synthesis, an asymmetric environment is required, and chiral homogeneous catalysts are typically used to synthesize enantiopure pharmaceutical compounds (EPC). Nevertheless, homogeneous catalysts are difficult to recover after the reaction, generating additional problems and costs in practical processes. Thus, the development of chiral heterogeneous catalysts is a timely topic. In a more general context, such chiral materials cannot only be used for synthesis, but also to recognize and separate enantiomers. In the frame of these different challenges, we give in this review a short introduction to strategies to extrinsically and intrinsically modify heterogeneous metal matrixes for the enantioselective synthesis, recognition, and separation of chiral pharmaceutical compounds.


Assuntos
Metais , Estereoisomerismo , Preparações Farmacêuticas
6.
Resusc Plus ; 17: 100528, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38178963

RESUMO

Objective: Public health surveillance is essential for improving community health. The Cardiac Arrest Registry to Enhance Survival (CARES) is a surveillance system for out-of-hospital cardiac arrest (OHCA). We describe results of the organized statewide implementation of Ohio CARES. Methods: We performed a retrospective analysis of CARES enactment in Ohio. Key elements included: establishment of statewide leadership, appointment of a dedicated coordinator, conversion to a statewide subscription, statewide dissemination of information, fundraising from internal and external stakeholders, and conduct of resuscitation academies. We identified all adult (≥18 years) OHCA reported in the registry during 2013-2020. We evaluated OHCA characteristics before (2013-2015) and after (2016-2019) statewide implementation using chi-square test. We evaluated trends in OHCA outcomes using the Cochran-Armitage test of trend. Results: Statewide CARES promotion increased participation from 2 (urban) to 136 (129 urban, 7 rural) EMS agencies. Covered population increased from 1.2 M (10% of state) to 4.8 M (41% of state). After statewide implementation, OHCA populations increased male (58.1% vs 60.8%, p < 0.01), white (50.1% vs 63.7%, p < 0.01), bystander witnessed (26.9% vs 32.9%, p < 0.01) OHCAs. Bystander CPR (34.7% vs 33.2%, p = 0.22), bystander AED (13.5% vs 12.3%, p = 0.55) and initial rhythm (shockable 18.0% vs 18.3%, p = 0.32) did not change. From 2013 to 2019 there were temporal increases in ROSC (29.7% to 31.9%, p-trend = 0.028), survival (7.4% to 12.3%, p-trend < 0.001) and survival with good neurologic outcome (5.6% to 8.6%, p-trend = 0.047). Conclusion: The organized statewide implementation of CARES in Ohio was associated with marked increases in community uptake and concurrent observed improvements in patient outcomes. These results highlight key lessons for community-wide fostering of OHCA surveillance.

7.
Rofo ; 196(3): 273-282, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37944940

RESUMO

PURPOSE: To utilize 4 D flow MRI to acquire normal values of "conventional 2 D flow MRI parameters" in healthy volunteers in order to replace multiple single 2 D flow measurements with a single 4 D flow acquisition. MATERIALS AND METHODS: A kt-GRAPPA accelerated 4 D flow sequence was used. Flow volumes were assessed by forward (FFV), backward (BFV), and net flow volumes (NFV) [ml/heartbeat] and flow velocities by axial (VAX) and absolute velocity (VABS) [m/s] in 116 volunteers (58 females, 43 ±â€Š13 years). The aortic regurgitant fraction (RF) was calculated. RESULTS: The sex-neutral mean FFV, BFV, NFV, and RF in the ascending aorta were 93.5 ±â€Š14.8, 3.6 ±â€Š2.8, 89.9 ±â€Š0.6 ml/heartbeat, and 3.9 ±â€Š2.9 %, respectively. Significantly higher values were seen in males regarding FFV, BFV, NFV and RF, but there was no sex dependency regarding VAX and VABS. The mean maximum VAX was lower (1.01 ±â€Š0.31 m/s) than VABS (1.23 ±â€Š0.35 m/s). We were able to determine normal ranges for all intended parameters. CONCLUSION: This study provides quantitative 4 D flow-derived thoracic aortic normal values of 2 D flow parameters in healthy volunteers. FFV, BFV, NFV, and VAX did not differ significantly from single 2 D flow acquisitions and could therefore replace time-consuming multiple single 2 D flow acquisitions. VABS should not be used interchangeably. KEY POINTS: · 4 D flow MRI can be used to replace 2 D flow MRI measurements.. · The parameter absolute velocities can be assessed by 4 D flow MRI.. · There are sex-dependent differences regarding forward, backward, net aortic blood flow and the aortic valve regurgitant fraction..


Assuntos
Aorta , Imageamento por Ressonância Magnética , Masculino , Feminino , Humanos , Valores de Referência , Voluntários Saudáveis , Velocidade do Fluxo Sanguíneo/fisiologia , Aorta/diagnóstico por imagem , Imageamento Tridimensional , Reprodutibilidade dos Testes , Aorta Torácica/diagnóstico por imagem
8.
Adv Mater ; 36(6): e2307539, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37805916

RESUMO

Asymmetric modification of particles with various patches of different composition and size at predefined positions is an important challenge in contemporary surface chemistry, as such particles have numerous potential applications, ranging from materials science and (photo)catalysis to self-assembly and drug delivery. However, approaches allowing the synthesis of this kind of complex objects in the bulk of a solution in a straightforward way are currently lacking. In this context, bipolar electrochemistry (BE) is a powerful technique for the asymmetric modification of conducting objects. Herein, this approach is used for the highly controlled modification of particles with different metal patches, generated at specific locations of isotropic objects. The synthesis is carried out in the bulk of the solution and leads to predefined patterns of increasing complexity, including even a specific chiral arrangement of the patches.

9.
Angew Chem Int Ed Engl ; 63(6): e202312647, 2024 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-38018379

RESUMO

Cable bacteria are multicellular, filamentous bacteria that use internal conductive fibers to transfer electrons over centimeter distances from donors within anoxic sediment layers to oxygen at the surface. We extracted the fibers and used them as free-standing bio-based electrodes to investigate their electrocatalytic behavior. The fibers catalyzed the reversible interconversion of oxygen and water, and an electric current was running through the fibers even when the potential difference was generated solely by a gradient of oxygen concentration. Oxygen reduction as well as oxygen evolution were confirmed by optical measurements. Within living cable bacteria, oxygen reduction by direct electrocatalysis on the fibers and not by membrane-bound proteins readily explains exceptionally high cell-specific oxygen consumption rates observed in the oxic zone, while electrocatalytic water oxidation may provide oxygen to cells in the anoxic zone.


Assuntos
Sedimentos Geológicos , Sulfetos , Transporte de Elétrons , Sedimentos Geológicos/microbiologia , Sulfetos/metabolismo , Oxirredução , Bactérias/metabolismo , Oxigênio/metabolismo , Água/metabolismo , Eletrodos
10.
Adv Sci (Weinh) ; 11(9): e2306635, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38126582

RESUMO

Electromagnetically induced rotation is a key process of many technological systems that are used in daily life, especially for energy conversion. In this context, the Lorentz force-induced deviation of charges is a crucial physical phenomenon to generate rotation. Herein, they combine the latter with the concept of bipolar electrochemistry to design a wireless magnetoelectrochemical rotor. Such a device can be considered as a wet analog of a conventional electric motor. The main driving force that propels this actuator is the result of the synergy between the charge-compensating ion flux along a bipolar electrode and an external magnetic field applied orthogonally to the surface of the object. The trajectory of the wirelessly polarized rotor can be controlled by the orientation of the magnetic field relative to the direction of the global electric field, producing a predictable clockwise or anticlockwise motion. Fine-tuning of the applied electric field allows for addressing conducting objects having variable characteristic lengths.

11.
Chemistry ; 29(61): e202303308, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37857579

RESUMO

Invited for the cover of this issue are the groups of Chularat Wattanakit and Alexander Kuhn at the Vidyasirimedhi Institute of Science and Technology and the University of Bordeaux. The two tunnels in the image illustrate the entrance into a porous heterogeneous catalyst for the stereoselective transformation of adrenalone into the desired epinephrine stereoisomer. Read the full text of the article at 10.1002/chem.202302054.

16.
Nat Commun ; 14(1): 6390, 2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37828004

RESUMO

Artificial actuators have been extensively studied due to their wide range of applications from soft robotics to biomedicine. Herein we introduce an autonomous bi-enzymatic system where reversible motion is triggered by the spontaneous oxidation and reduction of glucose and oxygen, respectively. This chemo-mechanical actuation is completely autonomous and does not require any external trigger to induce self-sustained motion. The device takes advantage of the asymmetric uptake and release of ions on the anisotropic surface of a conducting polymer strip, occurring during the operation of the enzymes glucose oxidase and bilirubin oxidase immobilized on its surface. Both enzymes are connected via a redox polymer at each extremity of the strip, but at the opposite faces of the polymer film. The time-asymmetric consumption of both fuels by the enzymatic reactions produces a double break of symmetry of the film, leading to autonomous actuation. An additional break of symmetry, introduced by the irreversible overoxidation of one extremity of the polymer film, leads to a crawling-type motion of the free-standing polymer film. These reactions occur in a virtually unlimited continuous loop, causing long-term autonomous actuation of the device.

17.
Chem Sci ; 14(39): 10664-10670, 2023 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-37829015

RESUMO

Multimodal imaging is a powerful and versatile approach that integrates and correlates multiple optical modalities within a single device. This concept has gained considerable attention due to its potential applications ranging from sensing to medicine. Herein, we develop several wireless multimodal light-emitting chemical systems by coupling two light sources based on different physical principles: electrochemiluminescence (ECL) occurring at the electrode interface and a light-emitting diode (LED) switched on by an electrochemically triggered electron flow. Endogenous (thermodynamically spontaneous redox process) and exogenous (requiring an external power source) bipolar electrochemistry acts as a driving force to trigger both light emissions at different wavelengths. The results presented here interconnect optical imaging and electrochemical reactions, providing a novel and so far unexplored alternative to design autonomous hybrid systems with multimodal and multicolor optical readouts for complex bio-chemical systems.

18.
J Phys Chem C Nanomater Interfaces ; 127(30): 14704-14710, 2023 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-37554549

RESUMO

Rotation is an interesting type of motion that is currently involved in many technological applications. In this frame, different and sophisticated external stimuli to induce rotation have been developed. In this work, we have designed a simple and original self-propelled bimetallic Janus rotor powered by the synergy between a spontaneous electric and ionic current, produced by two coupled redox reactions, and a magnetic field, placed orthogonal to the surface of the device. Such a combination induces a magnetohydrodynamic vortex at each extremity of the rotor arm, which generates an overall driving force able to propel the rotor. Furthermore, the motion of the self-polarized object can be controlled by the direction of the spontaneous electric current or the orientation of the external magnetic field, resulting in a predictable clockwise or anticlockwise motion. In addition, these devices exhibit directional corkscrew-type displacement, when representing their displacement as a function of time, producing time-space specular behavior. The concept can be used to design alternative self-mixing systems for a variety of (micro)fluidic equipment.

19.
Chemistry ; 29(61): e202302054, 2023 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-37555292

RESUMO

Enantioselective catalysis is of crucial importance in modern chemistry and pharmaceutical science. Although various concepts have been used for the development of enantioselective catalysts to obtain highly pure chiral compounds, most of them are based on homogeneous catalytic systems. Recently, we successfully developed nanostructured metal layers imprinted with chiral information, which were applied as electrocatalysts for the enantioselective synthesis of chiral model compounds. However, so far such materials have not been employed as heterogeneous catalysts for the enantioselective synthesis of real pharmaceutical products. In this contribution, we report the asymmetric synthesis of chiral pharmaceuticals (CPs) with chiral imprinted Pt-Ir surfaces as a simple hydrogenation catalyst. By fine-tuning the experimental parameters, a very high enantioselectivity (up to 95 % enantiomeric excess) with good catalyst stability can be achieved. The designed materials were also successfully used as catalytically active stationary phases for the continuous asymmetric flow synthesis of pharmaceutical compounds. This illustrates the possibility of producing real chiral pharmaceuticals at such nanostructured metal surfaces for the first time.


Assuntos
Metais , Estereoisomerismo , Metais/química , Hidrogenação , Catálise , Preparações Farmacêuticas
20.
Nano Lett ; 23(17): 8180-8185, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37642420

RESUMO

Graphene monolayers have interesting applications in many fields due to their intrinsic physicochemical properties, especially when they can be postmodified with high precision. Herein, we describe the highly site-selective functionalization of freestanding graphene monolayers with platinum (Pt) clusters by bipolar electrochemistry. The deposition of such metal spots leads to catalytically active hybrid two-dimensional (2D) nanomaterials. Their catalytic functionality is illustrated by the spatially controlled decomposition of hydrogen peroxide, inducing motion at the water/air interface due to oxygen bubble evolution. A series of such 2D Janus structures with Pt deposition at predefined positions (corners and edges) is studied with respect to the generation of autonomous motion. The type and speed of motion can be fine-tuned by controlling the deposition time and location of the Pt clusters. These proof-of-principle experiments indicate that this type of hybrid 2D object opens up interesting perspectives in terms of applications, such as environmental detection or remediation.

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