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1.
Rev Sci Instrum ; 93(11): 113542, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36461474

RESUMO

Magnetization of inertial confinement implosions is a promising means of improving their performance, owing to the potential reduction of energy losses within the target and mitigation of hydrodynamic instabilities. In particular, cylindrical implosions are useful for studying the influence of a magnetic field, thanks to their axial symmetry. Here, we present experimental results from cylindrical implosions on the OMEGA-60 laser using a 40-beam, 14.5 kJ, 1.5 ns drive and an initial seed magnetic field of B0 = 30 T along the axes of the targets, compared with reference results without an imposed B-field. Implosions were characterized using time-resolved x-ray imaging from two orthogonal lines of sight. We found that the data agree well with magnetohydrodynamic simulations, once radiation transport within the imploding plasma is considered. We show that for a correct interpretation of the data in these types of experiments, explicit radiation transport must be taken into account.

2.
Phys Rev E ; 106(3-2): 035206, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36266806

RESUMO

Investigating the potential benefits of the use of magnetic fields in inertial confinement fusion experiments has given rise to experimental platforms like the Magnetized Liner Inertial Fusion approach at the Z-machine (Sandia National Laboratories) or its laser-driven equivalent at OMEGA (Laboratory for Laser Energetics). Implementing these platforms at MegaJoule-scale laser facilities, such as the Laser MegaJoule (LMJ) or the National Ignition Facility (NIF), is crucial to reaching self-sustained nuclear fusion and enlarges the level of magnetization that can be achieved through a higher compression. In this paper, we present a complete design of an experimental platform for magnetized implosions using cylindrical targets at LMJ. A seed magnetic field is generated along the axis of the cylinder using laser-driven coil targets, minimizing debris and increasing diagnostic access compared with pulsed power field generators. We present a comprehensive simulation study of the initial B field generated with these coil targets, as well as two-dimensional extended magnetohydrodynamics simulations showing that a 5 T initial B field is compressed up to 25 kT during the implosion. Under these circumstances, the electrons become magnetized, which severely modifies the plasma conditions at stagnation. In particular, in the hot spot the electron temperature is increased (from 1 keV to 5 keV) while the density is reduced (from 40g/cm^{3} to 7g/cm^{3}). We discuss how these changes can be diagnosed using x-ray imaging and spectroscopy, and particle diagnostics. We propose the simultaneous use of two dopants in the fuel (Ar and Kr) to act as spectroscopic tracers. We show that this introduces an effective spatial resolution in the plasma which permits an unambiguous observation of the B-field effects. Additionally, we present a plan for future experiments of this kind at LMJ.

6.
J Eur Acad Dermatol Venereol ; 34(8): 1672-1683, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32012377

RESUMO

Folliculitis is an inflammatory process involving the hair follicle, frequently attributed to infectious causes. Malassezia, an established symbiotic yeast that can evolve to a skin pathogen with opportunistic attributes, is a common source of folliculitis, especially when intrinsic (e.g. immunosuppression) or extrinsic (high ambient temperature and humidity, clothing) impact on the hair follicle and the overlying skin microenvironment. Our aim was to critically review the pathophysiology and clinical characteristics of Malassezia folliculitis, to describe laboratory methods that facilitate diagnosis and to systematically review treatment options. Malassezia folliculitis manifests as a pruritic, follicular papulopustular eruption distributed on the upper trunk. It commonly affects young to middle-aged adults and immunosuppressed individuals. Inclusion into the differential diagnosis of folliculitis is regularly oversighted, and the prerequisite-targeted diagnostic procedures are not always performed. Sampling by tape stripping or comedo extractor and microscopic examination of the sample usually identifies the monopolar budding yeast cells of Malassezia without the presence of hyphae. However, confirmation of the diagnosis with anatomical association with the hair follicle is performed by biopsy. For systematic review of therapies, PubMed was searched using the search string "(malassezia" [MeSH Terms] OR "malassezia" [All Fields] OR pityrosporum [All Fields]) AND "folliculitis" [MeSH Terms] and EMBASE was searched using the search string: 'malassezia folliculitis.mp OR pityrosporum folliculitis.mp'. In total, 28 full-length studies were assessed for eligibility and 21 were selected for inclusion in therapy evaluation. Conclusively Malassezia folliculitis should be considered in the assessment of truncal, follicular skin lesions. Patient's history, comorbidities and clinical presentation are usually indicative, but microscopically and histological examination is needed to confirm the diagnosis. Adequate samples obtained with comedo extractor and serial sections in the histological material are critical for proper diagnosis. Therapy should include systemic or topical measures for the control of the inflammation, as well as the prevention of recurrences.


Assuntos
Acne Vulgar , Dermatomicoses , Foliculite , Malassezia , Adulto , Dermatomicoses/diagnóstico , Dermatomicoses/tratamento farmacológico , Foliculite/diagnóstico , Foliculite/tratamento farmacológico , Humanos , Pessoa de Meia-Idade , Pele
7.
Musculoskelet Surg ; 103(1): 15-21, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29845407

RESUMO

Hamate fractures are exceedingly rare clinical entities. However, the diagnosis and treatment of these injuries are often delayed and can severely handicap the performance of affected laborers or athletes. This review focuses on fractures of the hamate and provides an update on the current consensus as to mechanism, diagnosis, management, and complications after such injuries.


Assuntos
Fraturas Ósseas , Hamato/lesões , Traumatismos em Atletas/diagnóstico por imagem , Traumatismos em Atletas/etiologia , Traumatismos em Atletas/terapia , Diagnóstico Diferencial , Fixação de Fratura/métodos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/etiologia , Fraturas Ósseas/terapia , Humanos , Imobilização , Tomografia Computadorizada por Raios X
9.
Br J Dermatol ; 167(3): 496-505, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22533375

RESUMO

BACKGROUND: The aryl hydrocarbon receptor (AhR) is a nuclear receptor and transcriptional regulator with pleiotropic effects. The production of potent AhR ligands by Malassezia yeasts, such as indirubin, indolo[3,2-b]carbazole (ICZ), tryptanthrin and malassezin, has been associated with the pathogenesis of seborrhoeic dermatitis and pityriasis versicolor. Antigen-presenting cells in the skin can encounter microbes in the presence of these bioactive metabolites that could potentially modulate their function. OBJECTIVES: To study the effects of the aforementioned naturally occurring ligands on AhR activation and Toll-like receptor (TLR)-induced maturation in human monocyte-derived dendritic cells (moDCs). METHODS: These indoles were screened for AhR activation capacity in moDCs employing CYP1A1 and CYP1B1 induction as read out and for their effects on the function of moDCs after TLR-ligand stimulation. RESULTS: Indirubin and ICZ were the most potent AhR ligands and were selected for subsequent experiments. Concurrent exposure of moDCs to indirubin or ICZ together with TLR agonists significantly augmented the AhR-mediated CYP1A1 and CYP1B1 gene expression. Additionally, mature DCs that were subsequently stimulated with AhR ligands showed increased AhR target gene expression. Moreover, these ligands limited TLR-induced phenotypic maturation (CD80, CD83, CD86, MHC II upregulation) of moDCs, reduced secretion of the inflammatory cytokines interleukin (IL)-6 and IL-12, and decreased their ability to induce alloreactive T-lymphocyte proliferation. CONCLUSIONS: These results demonstrate that AhR agonists of yeast origin are able to inhibit moDC responses to TLR ligands and that moDCs can adapt through increased transcription of metabolizing enzymes such as CYP1A1 and CYP1B1.


Assuntos
Células Dendríticas/efeitos dos fármacos , Indóis/farmacologia , Malassezia , Receptores de Hidrocarboneto Arílico/efeitos dos fármacos , Receptores Toll-Like/antagonistas & inibidores , Hidrocarboneto de Aril Hidroxilases/metabolismo , Carbazóis/farmacologia , Células Cultivadas , Senescência Celular/fisiologia , Citocromo P-450 CYP1A1/metabolismo , Citocromo P-450 CYP1B1 , Células Dendríticas/metabolismo , Humanos , Interleucina-12/biossíntese , Interleucina-6/biossíntese , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Quinazolinas/farmacologia
10.
Biosystems ; 84(1): 49-72, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16386355

RESUMO

This paper presents an approach to ecological/evolutionary modelling that is inspired by natural bacterial ecosystems and bacterial evolution. An individual-based artificial ecosystem model is proposed, which is designed to explore the evolvability of adaptive behavioural strategies in artificial bacteria represented by rule-based learning classifier systems. The proposed ecosystem model consists of a n-dimensional environmental grid, which can contain different types of artificial resources in arbitrary arrangements. The resources provide the energy that is necessary for the organisms to sustain life, and can trigger different types of behaviour in the organisms, such as movement towards nutrients and away from toxic substances, growth, and the controlled release of signalling resources. The balance between energy and material is modelled carefully to ensure that the ecosystem is dissipative. Those organisms that are able to efficiently exploit the available resources gradually accumulate enough energy to reproduce (by binary fission) and generate copies of themselves in the environment. Organisms are also able to produce their own resources, which can potentially be used as markers to send signals to other organisms (a behaviour known as quorum sensing). The complex relationships between stimuli and actions in the organisms are stochastically altered by means of mutations, thus enabling the organisms to adapt to their environment and maximise their lifespan and reproductive success. In this paper, the proposed bacterial ecosystem model is defined formally and its structure is discussed in detail. This is followed by results from simulation experiments that illustrate the model's operation and how it can be used in evolutionary modelling/computing scenarios.


Assuntos
Fenômenos Fisiológicos Bacterianos , Ecossistema , Modelos Biológicos , Bactérias/genética , Evolução Biológica , Simulação por Computador , Metabolismo Energético , Mutação , Interface Usuário-Computador
11.
Comp Funct Genomics ; 5(1): 100-4, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-18629041

RESUMO

This paper presents two approaches to the individual-based modelling of bacterial ecologies and evolution using computational tools. The first approach is a fine-grained model that is based on networks of interactivity between computational objects representing genes and proteins. The second approach is a coarser-grained, agent-based model, which is designed to explore the evolvability of adaptive behavioural strategies in artificial bacteria represented by learning classifier systems. The structure and implementation of these computational models is discussed, and some results from simulation experiments are presented. Finally, the potential applications of the proposed models to the solution of real-world computational problems, and their use in improving our understanding of the mechanisms of evolution, are briefly outlined.

12.
Am J Orthod Dentofacial Orthop ; 113(3): 271-5, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9517717

RESUMO

Direct bonding of brackets has become a routine procedure in clinical orthodontics. Many techniques and materials are currently advocated and used, the most recent being light-cured composites. Advantages of the light-cured systems are their relative ease of use, improved bracket placement, and more rapid set of the composite. For a new system to be clinically viable, it must possess properties that are at least as reliable as existing systems. The purpose of this longitudinal clinical study was to evaluate and compare the rate of success and/or failure between a visible light-cured bonding material (Sequence) and a chemically cured bonding material (System 1+), using both systems in every patient. Contralateral quadrants were bonded with each system respectively. A total of 32 patients were followed for a mean period of 11 months (range of 3 to 21 months), with a total of 531 brackets bonded, 265 with visible light-cured and 266 with chemically cured resins. Failures for each system were recorded and failure rates calculated. The failure rate of the visible light-cured composite was 11.3% and that of the chemically cured composite was 12%. A Chi-squared (chi2) test did not reveal any statistically significant differences between the failure rates of the two systems, (chi2 = 0.014, df-1, P > 0.9).


Assuntos
Colagem Dentária/métodos , Braquetes Ortodônticos , Cimentos de Resina/química , Condicionamento Ácido do Dente , Dente Pré-Molar , Fenômenos Químicos , Físico-Química , Distribuição de Qui-Quadrado , Resinas Compostas/química , Dente Canino , Falha de Equipamento , Estudos de Avaliação como Assunto , Feminino , Fluoretos/química , Seguimentos , Humanos , Incisivo , Luz , Estudos Longitudinais , Masculino , Metacrilatos/química , Poliuretanos/química , Reprodutibilidade dos Testes
13.
Artigo em Inglês | MEDLINE | ID: mdl-9456615

RESUMO

Condylar position between centric occlusion (CO) and centric relation (CR) was compared for 24 adolescent orthodontic patients at pretreatment, posttreatment, and during the retention phase of orthodontic treatment. Models were mounted using a face-bow transfer and CR interocclusal registrations. Differences in CO-CR were then measured at the condylar level in the x, y, and z dimensions. The data were analyzed statistically to determine the mean CO-CR differences in the sample as well as the magnitude and direction of the CO-CR differences from one time period to the next. Results showed that the mean three-dimensional distance between CO and CR tended to increase from pretreatment to the retention phase for the right and left sides, the left side showing a greater increase. Intraexaminer variability accounted for 20% to 25% of the total variability when all possible sources of variability were considered. Correlation with a second examiner in recording CR was in the range of .61 and .75 for the right and left sides, respectively. Interexaminer variability was found to be similar to the variability associated with the CO-CR discrepancies over time. Consequently, the differences in measurements obtained could be the result of changes in the CO-CR relationship, examiner variability, or a combination of both.


Assuntos
Relação Central , Oclusão Dentária Central , Má Oclusão/terapia , Ortodontia Corretiva , Adolescente , Criança , Feminino , Humanos , Registro da Relação Maxilomandibular , Masculino , Variações Dependentes do Observador , Aparelhos Ortodônticos , Avaliação de Resultados em Cuidados de Saúde , Planejamento de Assistência ao Paciente , Recidiva , Reprodutibilidade dos Testes , Fatores de Tempo
14.
Semin Orthod ; 2(3): 197-204, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9161289

RESUMO

This article is an overview of the treatment possibilities and the role of the orthodontist in the management of patients with cleft palate. Orthodontic intervention and treatment may be indicated soon after birth (infant orthopedics), in the deciduous, mixed, and permanent dentitions and also in the adult patient. This article focuses primarily on decision-making and procedural steps performed by the orthodontist during the permanent dentition stage. The need for coordinated interaction with other team members is emphasized.


Assuntos
Fissura Palatina/terapia , Má Oclusão/terapia , Ortodontia Corretiva , Adolescente , Fatores Etários , Anodontia/terapia , Transplante Ósseo , Criança , Pré-Escolar , Fissura Palatina/cirurgia , Terapia Combinada , Humanos , Lactente , Recém-Nascido , Má Oclusão/etiologia , Maxila/cirurgia , Osteotomia de Le Fort , Palato Mole/cirurgia , Equipe de Assistência ao Paciente
15.
Dent Clin North Am ; 39(2): 363-78, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7781832

RESUMO

Morphologic and functional requirements of the orthodontically treated occlusion are discussed in this article. In the past, orthodontic treatment has been viewed as both a cause and a cure for temporomandibular disorders. This article reviews the literature, orthodontic implications of occlusal appliance therapy, and case reports.


Assuntos
Má Oclusão/terapia , Ortodontia Corretiva , Adulto , Cefalometria , Feminino , Humanos , Má Oclusão/complicações , Placas Oclusais , Aparelhos Ortodônticos , Ortodontia Corretiva/efeitos adversos , Ortodontia Corretiva/métodos , Avaliação de Processos e Resultados em Cuidados de Saúde , Transtornos da Articulação Temporomandibular/etiologia , Transtornos da Articulação Temporomandibular/terapia
16.
Clin Exp Immunol ; 19(3): 485-97, 1975 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1166

RESUMO

A method is described for detecting the simultaneous presence of Fc and C3 receptors on mouse spleen cells. A proportion of both T cells and non-T cells bear both receptors. Both T-cell and non-T-cell Fc receptors were blocked by aggregated mouse IgG2 to the same degree. C3, but not Fc, receptors were blocked by factors present in the serum of irradiated mice or mice undergoing graft-versus-host reaction. Thymocytes activated by injection into irradiated F1 hybrid mice, and thymocytes regenerating after irradiation and bone marrow injection, appeared to have increased Fc receptors. A general role for Fc and C3 receptors in T cell-B cell co-operation is suggested.


Assuntos
Complemento C3 , Proteínas do Sistema Complemento , Fragmentos Fc das Imunoglobulinas , Linfócitos/imunologia , Animais , Sítios de Ligação , Células da Medula Óssea , Transplante de Medula Óssea , Feminino , Imunofluorescência , Reação Enxerto-Hospedeiro , Reação de Imunoaderência , Camundongos , Baço/imunologia , Linfócitos T/imunologia , Timo/imunologia , Transplante Homólogo
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