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1.
Angew Chem Int Ed Engl ; 62(32): e202218850, 2023 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-36637348

RESUMO

Hydrogen (H2 ) produced from renewables will have a growing impact on the global energy dynamics towards sustainable and carbon-neutral standards. The share of green H2 is still too low to meet the net-zero target, while the demand for high-quality hydrogen continues to rise. These factors amplify the need for economically viable H2 generation technologies. The present article aims at evaluating the existing technologies for high-quality H2 production based on solar energy. Technologies such as water electrolysis, photoelectrochemical and solar thermochemical water splitting, liquid metal reactors and plasma conversion utilize solar power directly or indirectly (as carbon-neutral electrons) and are reviewed from the perspective of their current development level, technical limitations and future potential.

2.
Sci Rep ; 13(1): 9345, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37291122

RESUMO

In this study, we present a method for directly coating monoliths with a CeO2/CuO catalyst using the urea-nitrate combustion method. The catalyst was characterized by means of XRD, SEM/EDX, and EPR measurements. Experimental results are described, when this catalyst was used for the preferential oxidation of CO. The catalytic activity for the CO-PrOx-reaction was measured by recording CO conversion as a function of the reaction temperature in a hydrogen-rich gas mixture in the presence and absence of water vapor. In a long-term test of over 310 h, the catalyst's long-term stability was demonstrated. Direct coating is shown to be a promising approach by which a larger amount of catalyst can be deposited onto the monolith in a single step than would be possible with washcoats.


Assuntos
Cério , Cobre , Oxirredução , Catálise
3.
Membranes (Basel) ; 13(2)2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36837623

RESUMO

In this study, we aim to adapt a solid oxide cell (SOC) to a membrane reactor for general chemical reactions to leverage the readily available multichannel design of the SOC. As a proof-of-concept, the developed reactor is tested for syngas production by the partial oxidation of methane using oxygen ion transport membranes (ITMs) to achieve oxygen separation and permeation. A La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) membrane and Ni/MgAl2O4 catalyst are used for oxygen permeation and the partial oxidation of methane, respectively. ANSYS Fluent is used to assess the reactor performance with the help of computational fluid dynamics (CFD) simulations. The membrane permeation process is chemical kinetics achieved by user-defined functions (UDFs). The simulation results show that the oxygen permeation rate depends on the temperature, air, and fuel flow rates, as well as the occurrence of reactions, which is consistent with the results reported in the literature. During isothermal operation, the product composition and the species distribution in the reactor change with the methane flow rate. When the molar ratio of fed methane to permeated oxygen is 2.0, the methane conversion and CO selectivity reach a high level, namely 95.8% and 97.2%, respectively, which agrees well with the experimental data reported in the literature. Compared to the isothermal operation, the methane conversion of the adiabatic operation is close to 100%. Still, the CO selectivity only reaches 61.6% due to the hot spot formation of 1491 K in the reactor. To reduce the temperature rise in the adiabatic operation, reducing the methane flow rate is an approach, but the price is that the productivity of syngas is sacrificed as well. In conclusion, the adaption of the SOC to a membrane reactor is achieved, and other reaction applications can be explored in the same way.

4.
Sci Rep ; 12(1): 1911, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-35115587

RESUMO

Many critical advances in research utilize techniques that combine high-resolution with high-content characterization at the single cell level. We introduce the MICS (MACSima Imaging Cyclic Staining) technology, which enables the immunofluorescent imaging of hundreds of protein targets across a single specimen at subcellular resolution. MICS is based on cycles of staining, imaging, and erasure, using photobleaching of fluorescent labels of recombinant antibodies (REAfinity Antibodies), or release of antibodies (REAlease Antibodies) or their labels (REAdye_lease Antibodies). Multimarker analysis can identify potential targets for immune therapy against solid tumors. With MICS we analysed human glioblastoma, ovarian and pancreatic carcinoma, and 16 healthy tissues, identifying the pair EPCAM/THY1 as a potential target for chimeric antigen receptor (CAR) T cell therapy for ovarian carcinoma. Using an Adapter CAR T cell approach, we show selective killing of cells only if both markers are expressed. MICS represents a new high-content microscopy methodology widely applicable for personalized medicine.


Assuntos
Biomarcadores Tumorais/metabolismo , Molécula de Adesão da Célula Epitelial/metabolismo , Imunofluorescência , Imunoterapia Adotiva , Neoplasias/metabolismo , Neoplasias/terapia , Fotodegradação , Análise de Célula Única , Antígenos Thy-1/metabolismo , Morte Celular , Citotoxicidade Imunológica , Ensaios de Triagem em Larga Escala , Humanos , Neoplasias/imunologia , Neoplasias/patologia , Receptores de Antígenos Quiméricos/genética , Receptores de Antígenos Quiméricos/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Linfócitos T/transplante
5.
Environ Int ; 152: 106474, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33711760

RESUMO

The reduction of greenhouse gas emissions is one of the greatest global challenges through 2050. Besides greenhouse gas emissions, air pollution, such as nitrogen oxide and particulate matter emissions, has gained increasing attention in agglomerated areas with transport vehicles being one of the main sources thereof. Alternative fuels that fulfill the greenhouse gas reduction goals also offer the possibility of solving the challenge of rising urban pollution. This work focuses on the electric drive option for heavy and light duty vehicle freight transport. In this study, fuel cell-electric vehicles, battery-electric vehicles and overhead catenary line trucks were investigated, taking a closer look at their potential to reduce greenhouse gas emissions and air pollution and also considering the investment and operating costs of the required infrastructure. This work was conducted using a bottom-up transport model for the federal state of North Rhine-Westphalia in Germany. Two scenarios for reducing these emissions were analyzed at a spatial level. In the first of these, selected federal highways with the highest traffic volume were equipped with overhead catenary lines for the operation of diesel-hybrid overhead trucks on them. For the second spatial scenario, the representative urban area of the city of Cologne was investigated in terms of air pollution, shifting articulated trucks to diesel-hybrid overhead trucks and rigid trucks, trailer trucks and light duty vehicles to battery-electric or fuel cell-electric drives. For the economic analysis, the building up of a hydrogen infrastructure in the cases of articulated trucks and all heavy duty vehicles were also taken into account. The results showed that diesel-hybrid overhead trucks are only a cost-efficient solution for highways with high traffic volume, whereas battery overhead trucks have a high uncertainty in terms of costs and technical feasibility. In general, the broad range of costs for battery overhead trucks makes them competitive with fuel cell-electric trucks. Articulated trucks have the highest potential to be operated as overhead trucks. However, the results indicated that air pollution is only partially reduced by switching conventional articulated trucks to electric drive models. The overall results show that a comprehensive approach such as fuel cell-electric drives for all trucks would most likely be more beneficial.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Gases de Efeito Estufa , Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Alemanha , Veículos Automotores , Emissões de Veículos/análise
6.
Sci Total Environ ; 727: 138583, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32330716

RESUMO

Harmful emissions like nitrogen oxide and particulate matter are one of the big challenges facing modern society. These emissions are especially apparent in agglomerations. Possible solutions to overcome this challenge within the framework of the transformation of the transport sector are the change of the transport vehicles of freight and passenger transport or changing the fuel of the vehicles. Determining the viability of both approaches requires analyses to determine which vehicles are the main polluters in urban areas. This study outlines a bottom-up approach for the calculation of road transport emissions on street level in the representative model region of North Rhine-Westphalia in Germany, considering eight different vehicle classes as well as diesel and gasoline as fuel. Part of the approach is the development of a street-section traffic volume map considering all streets in the model region using a developed multivariate linear regression model for Germany and existing traffic counts. Using the approach developed here, the urban areas of Herne, Oberhausen and Bochum were identified as hotspots with the highest specific nitrogen oxide emissions, while the urban areas of Herne, Oberhausen and Gelsenkirchen were identified as hotspots with the highest specific particulate matter emissions. A detailed investigation of Oberhausen as a representative emission hotspot showed that 91% of road transport nitrogen oxide emissions are produced by vehicles that use diesel fuel and 9% from vehicles with gasoline fuel, while gasoline vehicles account for 43% of the total distance driven and diesel vehicles for 57%. With respect to particulate matter emissions in the urban area of Oberhausen, 29% are produced by gasoline vehicles and 71% by diesel vehicles. However, only 22% of particulate matter emissions are exhaust emissions, while 78% are produced due to the abrasion of tires, brakes and the road.

7.
Clin Chem ; 51(10): 1923-32, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16055433

RESUMO

BACKGROUND: Use of microfluidics in point-of-care testing (POCT) will require on-board fluidics, self-contained reagents, and multistep reactions, all at a low cost. Disposable microchips were studied as a potential POCT platform. METHODS: Micron-sized structures and capillaries were embedded in disposable plastics with mechanisms for fluidic control, metering, specimen application, separation, and mixing of nanoliter to microliter volumes. Designs allowed dry reagents to be on separate substrates and liquid reagents to be added. Control of surface energy to +/-5 dyne/cm2 and mechanical tolerances to < or = 1 microm were used to control flow propulsion into adsorptive, chromatographic, and capillary zones. Fluidic mechanisms were combined into working examples for urinalysis, blood glucose, and hemoglobin A(1c) testing using indicators (substances that react with analyte, such as dyes, enzyme substrates, and diazonium salts), catalytic reactions, and antibodies as recognition components. Optical signal generation characterized fluid flow and allowed detection. RESULTS: We produced chips that included capillary geometries from 10 to 200 microm with geometries for stopping and starting the flow of blood, urine, or buffer; vented chambers for metering and splitting 100 nL to 30 microL; specimen inlets for bubble-free specimen entry and containment; capillary manifolds for mixing; microstructure interfaces for homogeneous transfer into separation membranes; miniaturized containers for liquid storage and release; and moisture vapor barrier seals for easy use. Serum was separated from whole blood in <10 s. Miniaturization benefits were obtained at 10-200 microm. CONCLUSION: Disposable microchip technology is compatible with conventional dry-reagent technology and allows a highly compact system for complex assay sequences with minimum manual manipulations and simple operation.


Assuntos
Hemoglobinas Glicadas/análise , Técnicas Analíticas Microfluídicas/instrumentação , Técnicas Analíticas Microfluídicas/métodos , Microfluídica/instrumentação , Microfluídica/métodos , Glicemia/análise , Desenho de Equipamento , Humanos , Imunoensaio/instrumentação , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade , Propriedades de Superfície , Urinálise/instrumentação
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