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2.
Sci Rep ; 12(1): 2905, 2022 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-35190619

RESUMO

We present a comprehensive analysis of the out-of-equilibrium Casimir pressure between two high-[Formula: see text] superconducting plates, each kept at a different temperature. Two interaction regimes can be distinguished. While the zero-point energy dominates in the near field, thermal effects become important at large interplate separations causing a drop in the force's magnitude compared with the usual thermal-equilibrium case. Our detailed calculations highlight the competing role played by propagating and evanescent modes. Moreover, as one of the plates undergoes the superconducting transition, we predict an abrupt change in the force for any plate distance, which has not been previously observed in other systems. The sensitivity of the dielectric function of the high-[Formula: see text] superconductors makes them ideal systems for a possible direct measurement of the out-of-equilibrium Casimir pressure.

3.
Sci Rep ; 10(1): 16066, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32999404

RESUMO

Near-field radiative heat transfer (NFRHT) management can be achieved using high-temperature superconductors. In this work, we present a theoretical study of the radiative heat transfer between two [Formula: see text] (YBCO) slabs in three different scenarios: Both slabs either in the normal or superconducting state, and only one of them below the superconductor critical temperature [Formula: see text]. The radiative heat transfer is calculated using Rytov's theory of fluctuating electrodynamics, while a two-fluid model describes the dielectric function of the superconducting materials. Our main result is the significant suppression of the NFRHT when one or both of the slabs are superconducting, which is explained in terms of the detailed balance of the charge carriers density together with the sudden reduction of the free electron scattering rate. A critical and unique feature affecting the radiative heat transfer between high-temperature superconductors is the large damping of the mid-infrared carriers which screens the surface plasmon excitation.

4.
Chaos ; 30(9): 093132, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33003944

RESUMO

In order to elucidate central elements underlying type 2 diabetes, we constructed a regulatory network model involving 37 components (molecules, receptors, processes, etc.) associated to signaling pathways of pancreatic beta-cells. In a first approximation, the network topology was described by Boolean rules whose interacting dynamics predicted stationary patterns broadly classified as health, metabolic syndrome, and diabetes stages. A subsequent approximation based on a continuous logic analysis allowed us to characterize the progression of the disease as transitions between these states associated to alterations of cell homeostasis due to exhaustion or exacerbation of specific regulatory signals. The method allowed the identification of key transcription factors involved in metabolic stress as essential for the progression of the disease. Integration of the present analysis with existent mathematical models designed to yield accurate account of experimental data in human or animal essays leads to reliable predictions for beta-cell mass, insulinemia, glycemia, and glycosylated hemoglobin in diabetic fatty rats.


Assuntos
Diabetes Mellitus Tipo 2 , Células Secretoras de Insulina , Animais , Redes Reguladoras de Genes , Homeostase , Humanos , Ratos , Transdução de Sinais
6.
Rev. chil. radiol ; 25(2): 67-70, jun. 2019. ilus
Artigo em Espanhol | LILACS | ID: biblio-1013851

RESUMO

El tumor desmoides es un tumor benigno raro, de origen fibroblastico no inflamatorio, algunas veces referido como fibromatosis no agresiva. Su etiología aún no está completamente clara, sin embargo, se asocia habitualmente a trauma previo y/o procedimientos quirúrgicos. La ubicación más frecuente es abdominal, el cual posee características imagenologicas claras, al igual que su presentación musculo esquelética plantar. La presentación fuera de estos lugares es infrecuente y difícil de diagnosticar. Presentamos un caso de un tumor desmoides cervical que genero un gran desafío diagnóstico, identificando sus claves diagnósticas y realizando una revisión de la bibliografía al respecto para esta ubicación.


Desmoid tumours are a rare benign tumour of fibroblastic non inflammatory origin, sometimes referred as non aggressive fibromatosis.The etiology is not yet completely clear, however, it is usually associated with previous trauma and / or surgical procedures. The most frequent location is in the abdomen, which has typical images characteristics, as well as its skeletal muscle presentation at the plantar level. The presentation outside these places is infrequent and difficult to diagnose. We present a case of a cervical desmoid tumour that generated a great diagnostic challenge, identifying its key imaging characteristics and performing a literature review of the bibliography regarding this location.


Assuntos
Humanos , Masculino , Adulto , Fibroma/cirurgia , Fibroma/diagnóstico por imagem , Neoplasias de Cabeça e Pescoço/cirurgia , Neoplasias de Cabeça e Pescoço/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Fibroma/patologia , Neoplasias de Cabeça e Pescoço/patologia
10.
Biociencias ; 14(1): 27-39, 2019. tab, fig
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1006762

RESUMO

Introducción:El principal mecanismo patogénico que subyace la génesis y desarrollo de enfermedades del sistema circulatorio es la aterosclerosis. Es un proceso patológico complejo y progresivo de la pared arterial que afecta especialmente a las arterias coronarias, cerebrales y periféricas.Actualmente se habla sobre "La hipótesis infecciosa de la aterosclerosis". La infección por Helicobacter pyloriha sido una de las más investigadas a nivel global. Objetivo:Identificar H. pyloria partir de lesiones ateroscleróticas de pacientes que acuden a los servicios de cirugía cardiovascular y angiología de la ciudad de Barranquilla.Métodos:Se realizó un estudio descriptivo de corte transversal.En una muestra de 102 participantes.Los ateromas fueron tomados por personal experto en endarterectomía y disección de vasos sanguíneos. Los especímenes fueron embebidos en solución formaldehído al 4%.Se realizó extracción de ADN a partir de ateromas. El diagnóstico molecular de H. Pylorise realizó por PCR ANIDADA, evidenciando un fragmento de 120 pb posterior a la electroforesis en gel de agarosa al 3,5% en TBE 0,5X. Resultados:Se obtuvieron 102 muestras de ateromas. Una muestra resultó positiva para H. pylori(Muestra #14; 1/102).El tejido aterosclerótico fue obtenido a partir de arteria coronaria derecha. Conclusión: La hipótesis infecciosa de la aterosclerosis ha sido uno de los principales temas de investigación a nivel mundial en las últimas décadas. La infección por H. pylori es un factorde riesgo, sin embargo, varios estudios son necesarios para poder concluir de manera más precisa.


Introduction:The main pathogenic mechanism underlying the genesis and development of diseases of the circulatory system is atherosclerosis. It is a complex and progressive pathological process of the arterial wall that affects especially the coronary, cerebral and peripheral arteries. Currently, there is talk about "The infectious hypothesis of atherosclerosis". Helicobacter pyloriinfection has been one of the most researched worldwide. Objective:To identify H. pylori from atherosclerotic lesions of patients who attend the cardiovascular and angiology services of the city of Barranquilla. Methods:A descriptive cross-sectional study was carried out. In a sample of 102 participants. The atheromas were taken by expert personnel in endarterectomy and dissection of blood vessels. The specimens were embedded in 4% formaldehyde solution. DNA extraction was performed from atheromas. The molecular diagnosis of H. pyloriwas performed by ANIDADA PCR, evidencing a 120 bp fragment after electrophoresis in a 3.5% agarose gel in 0.5X TBE. Results:102 samples of atheromas were obtained. One sample was positive for H. pylori (Sample # 14, 1/102). The atherosclerotic tissue was obtained from the right coronary artery. Conclusion:The infectious hypothesis of atherosclerosis has been one of the main research topics worldwide in recent decades. H. pyloriinfection is a risk factor, however, several studies are necessary to be able to conclude more accurately


Assuntos
Humanos , Química Ambiental , Sistema Cardiovascular , Coração
12.
Biociencias ; 13(2018): 97-110, 2018. fig
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-981189

RESUMO

Introducción:Las enfermedades del sistema circulatorio representan uno de los mayores problemas de salud pública a nivel mundial, nacional y regional. Elmecanismo patogénico que subyace esta patología es la aterosclerosis. Existenvarios factores que favorecen la etiopatogeniade la lesión aterosclerótica.Las infecciones, juegan un papel importante.La infección por el Virus del Herpes Simplexse ha considerado como un factor de riesgo emergente. Objetivo:Realizar diagnósticomolecular de infección porVirus Herpes Simplex tipo 1 y tipo 2en tejido aterosclerótico humano.Método:Se realizó extracción de ADN viral a partir de ateromas usando el kit comercial PureGenomeTM Tissue DNA Extraction.La amplificación delmaterial genético viralse realizó porPCR en tiempo real (qPCR) con el kit comercial "Human Herpes Virus 2 (Herpes simplex type 2)UL36 region genesig Standard Kit y Human Herpes Virus 1 (Herpes simplex type 1) Capsid assembly and DNA maturation gene. Genesig Standard Kit".Resultados:En total se obtuvieron 102 muestras de ateromas, extraídas de diferentes fuentes anatómicas. Tresmuestras resultaronpositivas para VHS tipo 1(3/102).Ninguna muestra evidenció material genético para VHS tipo 2 (0/102). Conclusión:La etiopatogenia de la aterosclerosis es un proceso altamente complejo.Los virus juegan un papel importante, en especial la infección por Virus del herpes simplex tipo 1. La infección por estevirus genera cambios a nivel de las células vasculares y no vasculares, favoreciendo el acumulo de lipoproteínas de baja densidad químicamente oxidadas, importantespara la aterogénesis


Introduction:Diseases of the circulatory system represent one of the greatest public health problems worldwide, nationally and regionally. The pathogenic mechanism that underlies this pathology is atherosclerosis. There are several factors that favor the etiopathogeny of the atherosclerotic lesion. Infections play an important role. Infection with Herpes Simplex Virus has been considered as an emerging risk factor. Objective: To perform molecular diagnosis of infection by Herpes Simplex virus type 1 and type 2 in human atherosclerotic tissue. Method:Viral DNA extraction was performed from atheromas using the commercial PureGenomeTM Tissue DNA Extraction kit. The amplification of the viral genetic material was performed by real-time PCR (qPCR) with the commercial kit "Human Herpes Virus 2 (Herpes simplex type 2) UL36 region genesig Standard Kit and Human Herpes Virus 1 (Herpes simplex type 1) Capsid assembly and DNA maturation gene Genesig Standard Kit ". Results:A total of 102 samples of atheromas were obtained, extracted from different anatomicalsources. Three samples were positive for HSV type 1 (3/102). No sample showed genetic material for HSV type 2 (0/102). Conclusion:The etiopathogenesis of atherosclerosis is a highly complex process. Viruses play an important role, especially the infection by Herpes simplex virus type 1. The infection by this virus generates changes at the level of vascular and non-vascular cells, favoring the accumulation of chemically oxidized low density lipoproteins, important for the atherogenesis


Assuntos
Humanos , Vírus , Herpes Zoster , Biologia Molecular
13.
Actas Dermosifiliogr ; 107(5): 369-78, 2016 Jun.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-26826881

RESUMO

Sweet syndrome is the most representative entity of febrile neutrophilic dermatoses. It typically presents in patients with pirexya, neutrophilia, painful tender erytomatous papules, nodules and plaques often distributed asymmetrically. Frequent sites include the face, neck and upper extremities. Affected sites show a characteristical neutrophilic infiltrate in the upper dermis. Its etiology remains elucidated, but it seems that can be mediated by a hypersensitivity reaction in which cytokines, followed by infiltration of neutrophils, may be involved. Systemic corticosteroids are the first-line of treatment in most cases. We present a concise review of the pathogenesis, classification, diagnosis and treatment update of this entity.


Assuntos
Síndrome de Sweet , Algoritmos , Humanos , Síndrome de Sweet/diagnóstico , Síndrome de Sweet/terapia
15.
J Am Coll Surg ; 209(4): 446-452.e4, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19801317

RESUMO

BACKGROUND: We conducted a survey to determine the state of the trauma and critical care workforce and compensation for such surgeons. STUDY DESIGN: We sent questionnaires to 460 directors of Level I and Level II trauma centers in the US to gather information about their current and expected resource needs and compensation packages. RESULTS: We received responses from 117 directors (25%). Midlevel faculty mean salary was $282,000 +/- $85,000; with a mean bonus of $33,000 +/- $34,000; and a mean trauma call stipend of $1,690 +/- $900. Mean of the yearly representative value units of work was 7,845 +/- 3,154. An average of 1.7 +/- 1.4 trauma surgeon positions per center are currently unfilled (mean vacancy duration of 19 +/- 20 months), with another 1.2 +/- 0.5 full-time equivalents expected to retire within 3 years. A mean of 0.9 +/- 0.9 additional positions are expected to be added within the next 3 years because of the growing workload. By 2012, the US might have 1,500 unfilled trauma surgeon positions (with 2,250 occupied). CONCLUSIONS: Trauma and critical care surgeons in the US are clinically busy and well compensated for their efforts, but a severe shortage of surgeons in this specialty appears imminent.


Assuntos
Cuidados Críticos , Cirurgia Geral , Corpo Clínico Hospitalar/estatística & dados numéricos , Médicos/economia , Médicos/provisão & distribuição , Salários e Benefícios , Centros de Traumatologia , Traumatologia , Adulto , Idoso , Feminino , Pesquisas sobre Atenção à Saúde , Hospitais Rurais , Hospitais Urbanos , Humanos , Masculino , Pessoa de Meia-Idade , Mecanismo de Reembolso , Projetos de Pesquisa , Inquéritos e Questionários , Centros de Traumatologia/economia , Estados Unidos , Recursos Humanos , Carga de Trabalho
16.
Rev Sci Tech ; 28(1): 261-5, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19618630

RESUMO

The outbreak of highly pathogenic avian influenza (HPAI) H5N2 in Mexico in 1994 led to a clear increase in biosecurity measures and improvement of intensive poultry production systems. The control and eradication measures implemented were based on active surveillance, disease detection, depopulation of infected farms and prevention of possible contacts (identified by epidemiological investigations), improvement of biosecurity measures, and restriction of the movement of live birds, poultry products, by-products and infected material. In addition, Mexico introduced a massive vaccination programme, which resulted in the eradication of HPAI in a relatively short time in two affected areas that had a high density of commercial poultry.


Assuntos
Vírus da Influenza A Subtipo H5N2 , Influenza Aviária/epidemiologia , Animais , Controle de Doenças Transmissíveis/economia , Controle de Doenças Transmissíveis/métodos , Emergências/economia , Emergências/epidemiologia , Emergências/veterinária , Humanos , Vírus da Influenza A Subtipo H5N2/imunologia , Vírus da Influenza A Subtipo H5N2/patogenicidade , Influenza Aviária/economia , Influenza Aviária/prevenção & controle , Influenza Humana/prevenção & controle , México/epidemiologia , Aves Domésticas , Vacinação/economia , Vacinação/veterinária , Vacinas/classificação
17.
Virus Res ; 123(2): 138-46, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17014923

RESUMO

Syncytia formation in HIV infections is driven by the virus fusion-active molecules (Env) interacting with membrane components of hosts cells. HIV-syncytia are usually interpreted as pathogenic entities and although they may potentially vary in size, numbers and types of constituent cells, little is known about the extent and significance of their diversity. Here, we describe numerically the cell population dynamics and the diversity of syncytia produced in the in vitro cell-fusion between two Jurkat T cell lines, one CD4(+) and the other Env(+). Cell-fusion partners were differentially stained with the lipophilic DiI and DiO, or with the cytoplasmic CMFDA and CMTMR tracers and syncytia showing double fluorescence were counted in a flow cytometer. The total number of syncytia formed, their size, cellular complexity and ratio of CD4(+)/Env(+) cells recruited, varied significantly in relation with time of reaction and initial proportions of fusion partners. The considerable structural diversity of syncytia formed, in so limited an in vitro cell fusion reaction, suggests that a greater heterogeneity may be formed in the natural course of disease. Identification of the main determinants of syncytia diversity allows for a detailed study of the relation between the syncytia structure and function.


Assuntos
Antígenos CD4/metabolismo , Células Gigantes/citologia , HIV-1/química , Proteínas do Envelope Viral/metabolismo , Contagem de Células , Fusão Celular , Tamanho Celular , Infecções por HIV/virologia , HIV-1/fisiologia , Humanos , Células Jurkat/fisiologia
18.
Dev Biol (Basel) ; 130: 53-60, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18416017

RESUMO

The outbreaks of highly pathogenic avian influenza (HPAI) in Canada in 1966, the USA in 1984 and Mexico in 1994 led to a clear increase in biosecurity measures and improved intensive poultry production systems. In the past 12 years (1994-2006), there have been four outbreaks of HPAI on the American continent: in Mexico in 1994 (H5N2), in Chile in 2002 (H7N3), in the USA in 2004 (H5N2) and in Canada in 2004 (H7N3). In all cases, the control and eradication measures were based on prompt detection, depopulation of infected farms and epidemiological contacts, increased biosecurity measures and control of the movement of live poultry and their products, by-products and infected material. In Mexico, in addition to the aforementioned measures, the use of massive vaccination allowed eradication of HPAI in a relatively short time in two affected areas of high-density commercial poultry.


Assuntos
Controle de Doenças Transmissíveis/métodos , Virus da Influenza A Subtipo H5N1 , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Agricultura , Animais , Aves , Chile/epidemiologia , Comércio , Surtos de Doenças , Influenza Aviária/virologia , Cooperação Internacional , América do Norte/epidemiologia
19.
Dev Biol (Basel) ; 124: 125-6, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16450453

RESUMO

In December 1994, a highly pathogenic (HP) avian influenza (AI) outbreak occurred in Mexico, caused by the subtype H5N2, affecting two main regions of egg and poultry-meat production. At that time, governmental actions included immediate stamping out of the affected flocks, disinfection of affected premises, quarantine measures in the region, strict movement controls on poultry and their products and vaccination. With these policies, the disease was eradicated in a relatively short time. The last case of HPAI was detected in June 1995 and the country was declared as free of HPAI virus in January 1996 to the World Animal Health Organisation (OIE). Since then, Mexico has maintained a control programme against low pathogenic (LP) AI virus that is based on a zoning classification, movement controls and other strategies.


Assuntos
Surtos de Doenças/veterinária , Vírus da Influenza A Subtipo H5N2/imunologia , Influenza Aviária/epidemiologia , Influenza Aviária/prevenção & controle , Animais , Surtos de Doenças/prevenção & controle , México/epidemiologia , Aves Domésticas , Vacinação/métodos
20.
Opt Lett ; 28(19): 1814-6, 2003 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-14514110

RESUMO

We present a new technique for measuring atomic lifetimes with a mode-locked laser. A single laser pulse excites the atoms and a subsequent frequency-doubled pulse ionizes the excited-state atoms. The ions are collected and counted. The measurement is repeated using excitation and detection pulses with different time separations, which determines the excited-state decay rate. We demonstrated this technique for the 6P(3/2) state of cesium. The measured lifetime was 30.5 ns and had a statistical uncertainty of 0.1 ns. Systematic effects limited the overall experimental uncertainty to approximately 0.6 ns in this initial experiment.

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