Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Nat Commun ; 14(1): 5127, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37620348

RESUMO

The phase separation dynamics in graphitic anodes significantly affects lithium plating propensity, which is the major degradation mechanism that impairs the safety and fast charge capabilities of automotive lithium-ion batteries. In this study, we present comprehensive investigation employing operando high-resolution optical microscopy combined with non-equilibrium thermodynamics implemented in a multi-dimensional (1D+1D to 3D) phase-field modeling framework to reveal the rate-dependent spatial dynamics of phase separation and plating in graphite electrodes. Here we visualize and provide mechanistic understanding of the multistage phase separation, plating, inter/intra-particle lithium exchange and plated lithium back-intercalation phenomena. A strong dependence of intra-particle lithiation heterogeneity on the particle size, shape, orientation, surface condition and C-rate at the particle level is observed, which leads to early onset of plating spatially resolved by a 3D image-based phase-field model. Moreover, we highlight the distinct relaxation processes at different state-of-charges (SOCs), wherein thermodynamically unstable graphite particles undergo a drastic intra-particle lithium redistribution and inter-particle lithium exchange at intermediate SOCs, whereas the electrode equilibrates much slower at low and high SOCs. These physics-based insights into the distinct SOC-dependent relaxation efficiency provide new perspective towards developing advanced fast charge protocols to suppress plating and shorten the constant voltage regime.

2.
J Med Internet Res ; 25: e42621, 2023 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-37436815

RESUMO

BACKGROUND: Machine learning and artificial intelligence have shown promising results in many areas and are driven by the increasing amount of available data. However, these data are often distributed across different institutions and cannot be easily shared owing to strict privacy regulations. Federated learning (FL) allows the training of distributed machine learning models without sharing sensitive data. In addition, the implementation is time-consuming and requires advanced programming skills and complex technical infrastructures. OBJECTIVE: Various tools and frameworks have been developed to simplify the development of FL algorithms and provide the necessary technical infrastructure. Although there are many high-quality frameworks, most focus only on a single application case or method. To our knowledge, there are no generic frameworks, meaning that the existing solutions are restricted to a particular type of algorithm or application field. Furthermore, most of these frameworks provide an application programming interface that needs programming knowledge. There is no collection of ready-to-use FL algorithms that are extendable and allow users (eg, researchers) without programming knowledge to apply FL. A central FL platform for both FL algorithm developers and users does not exist. This study aimed to address this gap and make FL available to everyone by developing FeatureCloud, an all-in-one platform for FL in biomedicine and beyond. METHODS: The FeatureCloud platform consists of 3 main components: a global frontend, a global backend, and a local controller. Our platform uses a Docker to separate the local acting components of the platform from the sensitive data systems. We evaluated our platform using 4 different algorithms on 5 data sets for both accuracy and runtime. RESULTS: FeatureCloud removes the complexity of distributed systems for developers and end users by providing a comprehensive platform for executing multi-institutional FL analyses and implementing FL algorithms. Through its integrated artificial intelligence store, federated algorithms can easily be published and reused by the community. To secure sensitive raw data, FeatureCloud supports privacy-enhancing technologies to secure the shared local models and assures high standards in data privacy to comply with the strict General Data Protection Regulation. Our evaluation shows that applications developed in FeatureCloud can produce highly similar results compared with centralized approaches and scale well for an increasing number of participating sites. CONCLUSIONS: FeatureCloud provides a ready-to-use platform that integrates the development and execution of FL algorithms while reducing the complexity to a minimum and removing the hurdles of federated infrastructure. Thus, we believe that it has the potential to greatly increase the accessibility of privacy-preserving and distributed data analyses in biomedicine and beyond.


Assuntos
Algoritmos , Inteligência Artificial , Humanos , Ocupações em Saúde , Software , Redes de Comunicação de Computadores , Privacidade
3.
Infect Disord Drug Targets ; 22(3): e050122199975, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34986775

RESUMO

Hantaviruses are rodent viruses that have been identified as etiologic agents of 2 diseases in humans: Hemorrhagic Fever with Renal Syndrome (HFRS) and Nephropathiaepidemica (NE) in the Old World and Hantavirus Pulmonary Syndrome (HPS) in the New World. Orthohantavirus is a genus of single-stranded, enveloped, negative-sense RNA viruses in the family Hantaviridae of the order Bunyavirales. The important reservoir of Hantaviruses is rodents. Each virus serotype has its unique rodent host species and is transmitted to human beings with the aid of aerosolized virus, which is shed in urine, faeces and saliva and hardly by a bite of the contaminated host. Andes virus is the only Hantavirus identified to be transmitted from human-to-human and its major signs and symptoms include fever, headache, muscle aches, lungs filled with fluid, etc. In early 1993, this viral syndrome appeared in the Four Corner location in the southwestern United States. The only accepted therapeutics for this virus is Ribavirin. Recently, serological examinations to identify Hantavirus antibodies have become most popular for investigation among humans and rodent reservoirs.


Assuntos
Doenças Transmissíveis , Infecções por Hantavirus , Síndrome Pulmonar por Hantavirus , Orthohantavírus , Animais , Orthohantavírus/genética , Infecções por Hantavirus/diagnóstico , Infecções por Hantavirus/epidemiologia , Síndrome Pulmonar por Hantavirus/epidemiologia , Humanos , Roedores
4.
Drug Deliv Transl Res ; 11(5): 1849-1877, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33403646

RESUMO

Gastro-retentive drug delivery systems are some of the best technologies delivered through oral route. These mainly came into picture for their effective local action in the GI region, specifically for the drugs with narrow absorption window. In the recent decades, several technologies have evolved showing different mechanisms for retaining the drug in GI region for longer duration with increased bioavailability. Floatable, mucoadhesive, swelable, magnetic, nanofibrous, high-density, and expandable systems have been investigated extensively as the potential gastro-retentive strategies. The advances in the technologies studied, their clinical pertinence, and methods of drug delivery are described in this review with their immense future utilities. Their entry into the pharmaceutical market is a huge matter to look into as most of the studied strategies are facing problems and hence are underrated to overcome the clinical trials. Their success in the clinical trials are enormously required for gaining their access into the pharmaceutical market. Selection of the right technology for the right purpose through the right mechanism of action is to be done for obtaining the system with desired activity.


Assuntos
Sistemas de Liberação de Medicamentos , Nanofibras , Administração Oral , Disponibilidade Biológica , Preparações de Ação Retardada , Sistemas de Liberação de Medicamentos/métodos , Preparações Farmacêuticas
5.
Curr Mol Pharmacol ; 14(3): 306-320, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33172383

RESUMO

BACKGROUND: Vitiligo is an auto-immune disease with white-coloured disfiguring patches or spots on the skin surface. It is highly prevalent in several corners of the world. This disease spreads in different age groups. AIM: The main aim of this review is to provide an overview of pathophysiology and lipid-based nano-carriers for the treatment of vitiligo. METHODS: The conventional delivery systems available have limited efficacy due to less retention of the drug in the epidermal layer where melanocytes reside. In order to overcome these issues, an advanced delivery system with lipid-based nano-carriers for the treatment of vitiligo was proven to be better as per the literature explored. RESULTS: This review summarizes the pathophysiology along with novel lipid-based nano-carriers for the treatment of vitiligo. CONCLUSION: Though various treatment regimens are present for the disease, nano-lipid carrier systems are significantly gaining importance nowadays, due to their high effectivity in topically acting on the target site. Nano-lipid carrier systems such as liposomes, ethosomes, transethosomes and transferosomes can be said to be at the top of the list in acting effectively against vitiligo or several other tropical diseases.


Assuntos
Absorção Cutânea , Vitiligo , Sistemas de Liberação de Medicamentos , Humanos , Lipossomos , Pele/metabolismo , Vitiligo/tratamento farmacológico , Vitiligo/metabolismo
7.
Nano Lett ; 19(8): 5140-5148, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31322896

RESUMO

The stability of modern lithium-ion batteries depends critically on an effective solid-electrolyte interphase (SEI), a passivation layer that forms on the carbonaceous negative electrode as a result of electrolyte reduction. However, a nanoscopic understanding of how the SEI evolves with battery aging remains limited due to the difficulty in characterizing the structural and chemical properties of this sensitive interphase. In this work, we image the SEI on carbon black negative electrodes using cryogenic transmission electron microscopy (cryo-TEM) and track its evolution during cycling. We find that a thin, primarily amorphous SEI nucleates on the first cycle, which further evolves into one of two distinct SEI morphologies upon further cycling: (1) a compact SEI, with a high concentration of inorganic components that effectively passivates the negative electrode; and (2) an extended SEI spanning hundreds of nanometers. This extended SEI grows on particles that lack a compact SEI and consists primarily of alkyl carbonates. The diversity in observed SEI morphologies suggests that SEI growth is a highly heterogeneous process. The simultaneous emergence of these distinct SEI morphologies highlights the necessity of effective passivation by the SEI, as large-scale extended SEI growths negatively impact lithium-ion transport, contribute to capacity loss, and may accelerate battery failure.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...