Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Appl Mater Interfaces ; 10(37): 31580-31585, 2018 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-30136570

RESUMO

One promising route toward encoding information is to utilize the two stable electronic states of a spin crossover molecule. Although this property is clearly manifested in transport across single molecule junctions, evidence linking charge transport across a solid-state device to the molecular film's spin state has thus far remained indirect. To establish this link, we deploy materials-centric and device-centric operando experiments involving X-ray absorption spectroscopy. We find a correlation between the temperature dependencies of the junction resistance and the Fe spin state within the device's [Fe(H2B(pz)2)2(NH2-phen)] molecular film. We also factually observe that the Fe molecular site mediates charge transport. Our dual operando studies reveal that transport involves a subset of molecules within an electronically heterogeneous spin crossover film. Our work confers an insight that substantially improves the state-of-the-art regarding spin crossover-based devices, thanks to a methodology that can benefit device studies of other next-generation molecular compounds.

2.
Adv Mater ; 29(19)2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28295696

RESUMO

Materials science and device studies have, when implemented jointly as "operando" studies, better revealed the causal link between the properties of the device's materials and its operation, with applications ranging from gas sensing to information and energy technologies. Here, as a further step that maximizes this causal link, the paper focuses on the electronic properties of those atoms that drive a device's operation by using it to read out the materials property. It is demonstrated how this method can reveal insight into the operation of a macroscale, industrial-grade microelectronic device on the atomic level. A magnetic tunnel junction's (MTJ's) current, which involves charge transport across different atomic species and interfaces, is measured while these atoms absorb soft X-rays with synchrotron-grade brilliance. X-ray absorption is found to affect magnetotransport when the photon energy and linear polarization are tuned to excite FeO bonds parallel to the MTJ's interfaces. This explicit link between the device's spintronic performance and these FeO bonds, although predicted, challenges conventional wisdom on their detrimental spintronic impact. The technique opens interdisciplinary possibilities to directly probe the role of different atomic species on device operation, and shall considerably simplify the materials science iterations within device research.

3.
J Phys Chem Lett ; 7(13): 2310-5, 2016 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-27266579

RESUMO

A high spin polarization of states around the Fermi level, EF, at room temperature has been measured in the past at the interface between a few molecular candidates and the ferromagnetic metal Co. Is this promising property for spintronics limited to these candidates? Previous reports suggested that certain conditions, such as strong ferromagnetism, i.e., a fully occupied spin-up d band of the ferromagnet, or the presence of π bonds on the molecule, i.e., molecular conjugation, needed to be met. What rules govern the presence of this property? We have performed spin-resolved photoemission spectroscopy measurements on a variety of such interfaces. We find that this property is robust against changes to the molecule and ferromagnetic metal's electronic properties, including the aforementioned conditions. This affirms the generality of highly spin-polarized states at the interface between a ferromagnetic metal and a molecule and augurs bright prospects toward integrating these interfaces within organic spintronic devices.

4.
Acta Neurol Belg ; 114(3): 167-78, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24915752

RESUMO

Natalizumab (Tysabri(®)) is highly efficacious in controlling disease activity in relapsing multiple sclerosis (MS) patients. As it is one of the more recent therapies for MS, there remains a need for long-term safety and efficacy data of natalizumab in a clinical practice setting. The Tysabri observational program (TOP) is an open-label, multicenter, multinational, prospective observational study, aiming to recruit up to 6,000 patients with relapsing-remitting MS from Europe, Canada and Australia. The objectives of this study are to collect long-term safety and efficacy data on disease activity and disability progression. We report here the interim results of the 563 patients included in TOP between December 2007 and 2012 from Belgium. This patient cohort was older at baseline, had longer disease duration, higher neurological impairment, and a higher baseline annualized relapse rate, when compared to patients included in the pivotal phase III AFFIRM trial. Nevertheless, the efficacy of natalizumab was comparable. The annualized relapse rate on treatment was reduced by 90.70 % (p < 0.0001) with a cumulative probability of relapse of 26.87 % at 24 months. The cumulative probabilities of sustained disability improvement and progression at 24 months were 25.68 and 9.01 %, respectively. There were no new safety concerns over the follow-up period. Two cases of progressive multifocal leukoencephalopathy were diagnosed. Our results are consistent with other observational studies in the post-marketing setting.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Fatores Imunológicos/uso terapêutico , Esclerose Múltipla/tratamento farmacológico , Adolescente , Adulto , Distribuição por Idade , Idoso , Bélgica/epidemiologia , Estudos de Coortes , Avaliação da Deficiência , Feminino , Humanos , Cooperação Internacional , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Natalizumab , Vigilância de Produtos Comercializados , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do Tratamento , Adulto Jovem
5.
Acta Neurol Belg ; 112(2): 119-31, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22544726

RESUMO

In 2008, a group of Belgian epilepsy experts published recommendations for antiepileptic drug (AED) treatment of epilepsies in adults and children. Selection of compounds was based on the registration and reimbursement status in Belgium, the level of evidence for efficacy, common daily practice and the personal views and experiences of the authors. In November 2011 the validity of these recommendations was reviewed by the same group of Belgian epilepsy experts who contributed to the preparation of the original paper. The recommendations made in 2008 for initial monotherapy in paediatric patients were still considered to be valid, except for the first choice treatment for childhood absence epilepsy. This update therefore focuses on the treatment recommendations for initial monotherapy and add-on treatment in adult patients. Several other relevant aspects of treatment with AEDs are addressed, including considerations for optimal combination of AEDs (rational polytherapy), pharmacokinetic properties, pharmacodynamic and pharmacokinetic interaction profile, adverse effects, comorbidity, treatment of elderly patients, AED treatment during pregnancy, and generic substitution of AEDs.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Medicina Geral/normas , Guias como Assunto/normas , Adolescente , Adulto , Bélgica , Comorbidade , Bases de Dados Factuais/estatística & dados numéricos , Epilepsia/epidemiologia , Feminino , Humanos , Masculino , Adulto Jovem
6.
Acta Neurol Belg ; 108(4): 118-30, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19239040

RESUMO

The large choice of antiepileptic drugs (AEDs) in Belgium complicates the selection of the appropriate product for the individual patient. International guidelines on the treatment of epilepsy have been published, but are not tailored to the Belgian situation. This publication presents recommendations from a group of Belgian epilepsy experts for the practical management of epilepsy in general practice in Belgium. It includes recommendations for initial monotherapy and add-on treatment in adult patients (> or = 16 years) and initial monotherapy in paediatric patients (< 16 years). For these three situations a first choice AED is recommended. One or more alternative first choice AEDs are defined for patients in which certain patient- or AED-related factors preclude the use of the first choice product. Selection of compounds was based on the registration and reimbursement status in Belgium, the level of evidence of efficacy, common daily practice and the personal views and experiences of the authors. The paper reflects the situation in 2008. In addition to the treatment recommendations, other relevant points to consider in the treatment of epilepsy with AEDs are addressed, including comorbidity and age of the patient, the interaction potential, pharmacokinetic properties and safety profile of the AEDs, and generic substitution.


Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Medicina de Família e Comunidade , Fatores Etários , Bélgica , Comorbidade , Humanos , Convulsões/tratamento farmacológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...