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1.
Nanomaterials (Basel) ; 14(2)2024 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-38251099

RESUMO

Nanoparticles have many advantages as active materials, such as a short diffusion length, low charge transfer resistance, or a reduced probability of cracking. However, their low packing density makes them unsuitable for commercial battery applications. Hierarchically structured microparticles are synthesized from nanoscale primary particles by targeted aggregation. Due to their open accessible porosity, they retain the advantages of nanomaterials but can be packed much more densely. However, the intrinsic porosity of the secondary particles leads to limitations in processing properties and increases the overall porosity of the electrode, which must be balanced against the improved rate stability and increased lifetime. This is demonstrated for an established cathode material for lithium-ion batteries (LiNi0.33Co0.33Mn0.33O2, NCM111). For active materials with low electrical or ionic conductivity, especially post-lithium systems, hierarchically structured particles are often the only way to produce competitive electrodes.

2.
Med Teach ; 45(9): 1012-1018, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-36706166

RESUMO

BACKGROUND: To ensure high qualification standards in medical institutions, a questionnaire has been developed to evaluate the postgraduate medical education in Switzerland. AIM: This article describes the development and longitudinal analysis of a questionnaire using eight scales to assess the quality of postgraduate medical education. METHOD: The questionnaire has been administered to all residents every year since 2003. In 2020, 8,745 residents returned the questionnaire, resulting in a response rate of 70%. In addition, a survey is conducted annually among the directors of medical institutions. RESULTS: We present results of the directors' survey and the resident evaluation from 2020, as well as longitudinal data over 16 years. The mean values of the eight scales remained stable or increased slightly over the years. The decision-making culture scale is generally rated best by the residents, while the evidence-based medicine scale is rated as the least good. The most important drivers of residents' satisfaction with a training site are the work environment and leadership culture scales. The directors perceive the evaluation to be fair and useful. CONCLUSIONS: The questionnaire represents a reliable and useful tool for the quality control in postgraduate medical training. It provides yearly feedback to the directors regarding how the residents perceive their training giving insights for improvments.


Assuntos
Educação Médica , Internato e Residência , Humanos , Suíça , Inquéritos e Questionários , Controle de Qualidade
3.
Adv Sci (Weinh) ; 9(7): e2104605, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35001546

RESUMO

Magnesium-Sulfur batteries are one of most appealing options among the post-lithium battery systems due to its potentially high energy density, safe and sustainable electrode materials. The major practical challenges are originated from the soluble magnesium polysulfide intermediates and their shuttling between the electrodes, which cause high overpotentials, low sulfur utilization, and poor Coulombic efficiency. Herein, a functional Mo6 S8 modified separator is designed to effectively address these issues. Both the experimental results and density functional theory calculations show that the electrochemically active Mo6 S8 layer has a superior adsorption capability of polysulfides and simultaneously acts as a mediator to accelerate the polysulfide conversion kinetics. Remarkably, the magnesium-sulfur cell assembled with the functional separator delivers a high specific energy density (942.9 mA h g-1 in the 1st cycle) and can be cycled at 0.2 C for 200 cycles with a Coulombic efficiency of 96%. This work demonstrates a new design concept toward high-performance metal-sulfur batteries.

4.
iScience ; 24(5): 102437, 2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-33997708

RESUMO

Lithium-ion batteries (LIBs) have been proven as an enabling technology for consumer electronics, electro mobility, and stationary storage systems, and the steadily increasing demand for LIBs raises new challenges regarding their sustainability. The rising demand for comprehensive assessments of this technology's environmental impacts requires the identification of energy and materials consumed for its production, on lab to industrial scale. There are no studies available that provide a detailed picture of lab scale cell production, and only a few studies provide detailed analysis of the actual consumption, with large deviations. Thus, the present work provides an analysis of the energy flows for the production of an LIB cell. The analyzed energy requirements of individual production steps were determined by measurements conducted on a laboratory scale lithium-ion cell production and displayed in a transparent and traceable manner. For the comparison with literature values a distinction is made between the different production scales.

5.
Adv Mater ; 30(22): e1707100, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29611238

RESUMO

Fused silica glass is one of the most important high-performance materials for scientific research, industry, and society. However due to its high chemical and thermal resistance as well as high hardness, fused silica glass is notoriously difficult to structure. This work introduces Glassomer, a solid nanocomposite, which can be structured using polymer molding and subtractive technologies at submicrometer resolution. After polymer processing Glassomer is turned into optical grade fused silica glass during a final heat treatment. The resulting glass has the same optical transparency as commercial fused silica and a smooth surface with a roughness of a few nanometers. This work makes high-performance fused silica glass components accessible to high-throughput fabrication technologies and will enable numerous optical, photonic and medical applications in science and industry.

6.
Nature ; 544(7650): 337-339, 2017 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-28425999

RESUMO

Glass is one of the most important high-performance materials used for scientific research, in industry and in society, mainly owing to its unmatched optical transparency, outstanding mechanical, chemical and thermal resistance as well as its thermal and electrical insulating properties. However, glasses and especially high-purity glasses such as fused silica glass are notoriously difficult to shape, requiring high-temperature melting and casting processes for macroscopic objects or hazardous chemicals for microscopic features. These drawbacks have made glasses inaccessible to modern manufacturing technologies such as three-dimensional printing (3D printing). Using a casting nanocomposite, here we create transparent fused silica glass components using stereolithography 3D printers at resolutions of a few tens of micrometres. The process uses a photocurable silica nanocomposite that is 3D printed and converted to high-quality fused silica glass via heat treatment. The printed fused silica glass is non-porous, with the optical transparency of commercial fused silica glass, and has a smooth surface with a roughness of a few nanometres. By doping with metal salts, coloured glasses can be created. This work widens the choice of materials for 3D printing, enabling the creation of arbitrary macro- and microstructures in fused silica glass for many applications in both industry and academia.

7.
Adv Mater ; 28(23): 4646-50, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27060964

RESUMO

Liquid glass is a photocurable amorphous silica nanocomposite that can be structured using soft replication molds and turned into glass via thermal debinding and sintering. Simple polymer bonding techniques allow the fabrication of complex microsystems in glass like microfluidic chips. Liquid glass is a step toward prototyping of glass microstructures at low cost without requiring cleanroom facilities or hazardous chemicals.

9.
Nanotechnology ; 25(12): 125706, 2014 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-24577219

RESUMO

The development of highly conductive metallic electrodes with long-term reliability is in great demand for real industrialization of flexible electronics, which undergo repeated mechanical deformation during service. In the case of vacuum-deposited metallic electrodes, adequate conductivity is provided, but it degrades gradually during cyclic mechanical deformation. Here, we demonstrate a long-term reliable Ag electrode by inkjet printing. The electrical conductivity and the mechanical reliability during cyclic bending are investigated with respect to the nanoporous microstructure caused by post heat treatment, and are compared to those of evaporated Ag films of the same thickness. It is shown that there is an optimized nanoporous microstructure for inkjet-printed Ag films, which provides a high conductivity and improved reliability. It is argued that the nanoporous microstructure ensures connectivity within the particle network and at the same time reduces plastic deformation and the formation of fatigue damage. This concept provides a new guideline to develop an efficient method for highly conductive and reliable metallic electrodes for flexible electronics.

12.
Pol Arch Med Wewn ; 115(6): 612-6, 2006 Jun.
Artigo em Polonês | MEDLINE | ID: mdl-17263235

RESUMO

What will be the future of internal medicine in Europe? Because of rapidly growing concerns regarding the position of internal medicine in many European countries, the European Federation of Internal Medicine (EFIM) has established a working group to analyze the situation. Being well aware of the variation in working practices in the different countries, the members of the group used an "all-European" approach to answer the following questions: Are there problems for internal medicine? If so, what are these problems and why? Why do the health care systems in the European countries need internal medicine? Why do patients need internal medicine? What needs to be done? Internal medicine is the modern, clinical, and scientific medical discipline that is responsible for the care of adult patients with one or more complex, acute, or chronic illnesses. Internal medicine is the cornerstone of an integrated health care delivery service that is needed today. Decision-makers in politics and hospitals, insurers, journalists, and the general public need a better understanding of what internal medicine can offer to the health care system and to the individual patient.


Assuntos
Atenção à Saúde/tendências , Medicina Interna/tendências , Política , Sociedades Médicas/tendências , Adulto , Prestação Integrada de Cuidados de Saúde/tendências , Europa (Continente) , Medicina de Família e Comunidade/tendências , Previsões , Humanos , Medicina , Especialização
13.
Acta Clin Belg ; 60(3): 157-60, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16156377

RESUMO

What will be the future of Internal Medicine in Europe? Because of rapidly growing concerns regarding the position of Internal Medicine in many European countries, the European Federation of Internal Medicine has established a working group to analyze the situation. Being well aware of the variation of working practices in the different countries, the members of the group used an "all-European" approach to answer the following questions: Are there problems for Internal Medicine, what problems and why? Why do the health care systems of the European countries need Internal Medicine? Why do the patients need Internal Medicine? What needs to be done? Internal Medicine is the modern, clinical and scientific medical discipline taking care of adult patients with one or more complex, acute or chronic illnesses. Internal Medicine is the cornerstone of integrated health care delivery service that is needed today. Decision-makers in politics and hospitals, insurers, journalists and the general public need a better understanding of what Internal Medicine can offer to the health care system and to the individual patient.


Assuntos
Medicina Interna , Europa (Continente) , Previsões , Humanos , Medicina Interna/tendências , Política
14.
Eur J Intern Med ; 16(3): 214-217, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15967343

RESUMO

What will be the future of internal medicine in Europe? Because of rapidly growing concerns regarding the position of internal medicine in many European countries, the European Federation of Internal Medicine (EFIM) has established a working group to analyze the situation. Being well aware of the variation in working practices in the different countries, the members of the group used an "all-European" approach to answer the following questions: Internal medicine is the modern, clinical, and scientific medical discipline that is responsible for the care of adult patients with one or more complex, acute, or chronic illnesses. Internal medicine is the cornerstone of an integrated health care delivery service that is needed today. Decision-makers in politics and hospitals, insurers, journalists, and the general public need a better understanding of what internal medicine can offer to the health care system and to the individual patient.

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