Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 16 de 16
Filtrar
1.
Sci Rep ; 14(1): 13450, 2024 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862584

RESUMO

This study tested if a high-resolution, multi-modal, multi-scale retinal imaging instrument can provide novel information about structural abnormalities in vivo. The study examined 11 patients with very mild to moderate non-proliferative diabetic retinopathy (NPDR) and 10 healthy subjects using fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), adaptive optics scanning laser ophthalmoscopy (AO-SLO), adaptive optics OCT and OCTA (AO-OCT(A)). Of 21 eyes of 11 patients, 11 had very mild NPDR, 8 had mild NPDR, 2 had moderate NPDR, and 1 had no retinopathy. Using AO-SLO, capillary looping, inflections and dilations were detected in 8 patients with very mild or mild NPDR, and microaneurysms containing hyperreflective granular elements were visible in 9 patients with mild or moderate NPDR. Most of the abnormalities were seen to be perfused in the corresponding OCTA scans while a few capillary loops appeared to be occluded or perfused at a non-detectable flow rate, possibly because of hypoperfusion. In one patient with moderate NPDR, non-perfused capillaries, also called ghost vessels, were identified by alignment of corresponding en face AO-OCT and AO-OCTA images. The combination of multiple non-invasive imaging methods could identify prominent microscopic abnormalities in diabetic retinopathy earlier and more detailed than conventional fundus imaging devices.


Assuntos
Capilares , Retinopatia Diabética , Oftalmoscopia , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Retinopatia Diabética/diagnóstico por imagem , Retinopatia Diabética/patologia , Feminino , Masculino , Oftalmoscopia/métodos , Pessoa de Meia-Idade , Capilares/diagnóstico por imagem , Capilares/patologia , Adulto , Vasos Retinianos/diagnóstico por imagem , Vasos Retinianos/patologia , Idoso , Angiofluoresceinografia/métodos
2.
Foods ; 13(1)2023 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-38201064

RESUMO

The objective of this work was to carry out a preliminary study of the fractionation by supercritical CO2 (sc-CO2) extraction of two varieties of Peruvian beans (Phaseolus vulgaris L.), white (WB) and red (RB), to obtain two novel products: an oil rich in essential fatty acids and tocopherols and a defatted flour with high nutritional value and amino acids. The extraction temperature and pressure were optimized using the response surface methodology (RSM) and the extraction kinetics were optimized using the Spline equation. The results revealed that the best extraction conditions for WB and RB were 396.36 Bar, 40.46 °C, with an efficiency of 1.65%; and 391.995 Bar, 44.00 °C, with an efficiency of 1.12%, respectively. The WB and RB oils presented a high degree of polyunsaturation (63.2 and 52.8%, respectively), with oleic, linoleic, and linolenic fatty acids prevailing. Gamma-tocopherol was the predominant antioxidant in both oils. The residual flours (WB and RB) obtained after extraction with sc-CO2 had a high average content of proteins (23%), carbohydrates (61%), and minerals (3%). The limiting amino acids of WB were: Fen + Tyr, Leu, Lys, and in RB, only Leu was limiting. The viscosity of the solutions (20%) of the WB and RB flours mainly adjusted to the Waele's Ostwald model (r = 0.988). It is concluded that both products (oil and bean flour) obtained in an optimized manner using an eco-friendly technology with sc-CO2 have high nutrient and bioactive component content and can be used in the development of new ingredients and healthy foods of plant origin.

3.
Sci Rep ; 12(1): 9577, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35688890

RESUMO

We present a compact multi-modal and multi-scale retinal imaging instrument with an angiographic functional extension for clinical use. The system integrates scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT) and OCT angiography (OCTA) imaging modalities and provides multi-scale fields of view. For high resolution, and high lateral resolution in particular, cellular imaging correction of aberrations by adaptive optics (AO) is employed. The entire instrument has a compact design and the scanning head is mounted on motorized translation stages that enable 3D self-alignment with respect to the subject's eye by tracking the pupil position. Retinal tracking, based on the information provided by SLO, is incorporated in the instrument to compensate for retinal motion during OCT imaging. The imaging capabilities of the multi-modal and multi-scale instrument were tested by imaging healthy volunteers and patients.


Assuntos
Pupila , Retina , Humanos , Oftalmoscopia/métodos , Óptica e Fotônica , Retina/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos
4.
Rev. med. Chile ; 150(6): 821-827, jun. 2022. ilus, tab
Artigo em Espanhol | LILACS | ID: biblio-1424124

RESUMO

The accelerated scientific, technological, and social advances in recent years have posed new challenges for professional training institutions, where universities play a leading role. Medical schools have not been oblivious to this process. This is how Pontificia Universidad Católica de Chile implemented in 2015 a curricular reform derived from the joint work of academics, students and graduates. For this purpose, a model consisting of stages was followed, including the identification of the problem, general assessment of needs, definition of purpose and learning objectives. We worked with surveys, focus groups and committees of academics and students to identify and map content within the mesh, review terminal learning objectives while creating and reviewing courses for the vertically and horizontally integrated delivery of content and competencies. The first cohort of the new curriculum entered in 2015, consisting of 126 students. The implementation required constant follow-up and monitoring, establishing changes and adjustments according to educational needs and unforeseen conditions such as the COVID-19 pandemic. The implementation process of the new curriculum has been positive, adjusting to the defined strategic planning and responding to unexpected events.


Assuntos
Humanos , Estudantes de Medicina , Educação de Graduação em Medicina , Faculdades de Medicina , Currículo , Pandemias
5.
Rev Med Chil ; 150(6): 821-827, 2022 Jun.
Artigo em Espanhol | MEDLINE | ID: mdl-37906916

RESUMO

The accelerated scientific, technological, and social advances in recent years have posed new challenges for professional training institutions, where universities play a leading role. Medical schools have not been oblivious to this process. This is how Pontificia Universidad Católica de Chile implemented in 2015 a curricular reform derived from the joint work of academics, students and graduates. For this purpose, a model consisting of stages was followed, including the identification of the problem, general assessment of needs, definition of purpose and learning objectives. We worked with surveys, focus groups and committees of academics and students to identify and map content within the mesh, review terminal learning objectives while creating and reviewing courses for the vertically and horizontally integrated delivery of content and competencies. The first cohort of the new curriculum entered in 2015, consisting of 126 students. The implementation required constant follow-up and monitoring, establishing changes and adjustments according to educational needs and unforeseen conditions such as the COVID-19 pandemic. The implementation process of the new curriculum has been positive, adjusting to the defined strategic planning and responding to unexpected events.


Assuntos
Educação de Graduação em Medicina , Estudantes de Medicina , Humanos , Faculdades de Medicina , Pandemias , Currículo
6.
J Technol Transf ; 47(2): 556-579, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-33814697

RESUMO

This study explores the emergence of a new entrepreneurship phenomenon (digital social entrepreneurship) as a result of the collaboration among many agents (N-Helix), given the government's limited capacity to respond to the stakeholders' needs satisfaction related to an exogenous event (e.g., the COVID-19 pandemic). Our theory development is based on three ongoing academic debates related to (a) the unrepresentativeness of the stakeholder theory in entrepreneurship research; (b) the emergence of digital social entrepreneurship (DSE) as a bridge between stakeholders' needs, socio-economic actors, and digital-social initiatives; and (c) the role of N-Helix collaborations to facilitate the emergence of global knowledge-intensive initiatives and the rapid adoptions of open innovations. Our results support our assumptions about the positive mediation effect of DSE in the relationship between N-Helix collaborations and stakeholders' satisfaction. Notably, results show how pandemic has intensified these relationships and how DSE in N-Helix collaborations can generate social impacts globally. Some implications for policy-makers have emerged from our results that should be considered during/post-COVID-19 pandemic.

7.
Neuroimage ; 215: 116541, 2020 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31987995

RESUMO

Behavioral and cognitive tests in individuals who were malnourished as children have revealed malnutrition-related deficits that persist throughout the lifespan. These findings have motivated recent neuroimaging investigations that use highly portable functional near-infrared spectroscopy (fNIRS) instruments to meet the demands of brain imaging experiments in low-resource environments and enable longitudinal investigations of brain function in the context of long-term malnutrition. However, recent studies in healthy subjects have demonstrated that high-density diffuse optical tomography (HD-DOT) can significantly improve image quality over that obtained with sparse fNIRS imaging arrays. In studies of both task activations and resting state functional connectivity, HD-DOT is beginning to approach the data quality of fMRI for superficial cortical regions. In this work, we developed a customized HD-DOT system for use in malnutrition studies in Cali, Colombia. Our results evaluate the performance of the HD-DOT instrument for assessing brain function in a cohort of malnourished children. In addition to demonstrating portability and wearability, we show the HD-DOT instrument's sensitivity to distributed brain responses using a sensory processing task and measurements of homotopic functional connectivity. Task-evoked responses to the passive word listening task produce activations localized to bilateral superior temporal gyrus, replicating previously published work using this paradigm. Evaluating this localization performance across sparse and dense reconstruction schemes indicates that greater localization consistency is associated with a dense array of overlapping optical measurements. These results provide a foundation for additional avenues of investigation, including identifying and characterizing a child's individual malnutrition burden and eventually contributing to intervention development.


Assuntos
Encéfalo/diagnóstico por imagem , Transtornos da Nutrição Infantil/diagnóstico por imagem , Neuroimagem/instrumentação , Neuroimagem/métodos , Tomografia Óptica/instrumentação , Tomografia Óptica/métodos , Encéfalo/fisiopatologia , Criança , Transtornos da Nutrição Infantil/fisiopatologia , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Processamento de Sinais Assistido por Computador , Dispositivos Eletrônicos Vestíveis
8.
Rev. colomb. radiol ; 30(3): 5194-5198, Sept. 2019. ilus, graf
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-1290943

RESUMO

Los informes estructurados contextualizados cumplen tres características fundamentales: tienen una estructura uniforme que responde una pregunta clínica, son el producto de listas de chequeo estandarizadas o de árboles de conocimiento previamente concertados con equipos clínicos multidisciplinarios y se construyen a partir de cuadros de selección de atributos incorporados en los sistemas de informe electrónicos, adicionalmente, el atributo contextualizado hace referencia a la capacidad del informe de responder las preguntas clínicas de la situación actual del paciente, otorgando información relevante de forma concisa y clara a los médicos tratantes. Dentro de las principales ventajas de migrar hacia el informe estructurado se encuentran la uniformidad y la alta calidad del informe, el aumento en la concordancia intra e interobservador, así como la reducción de las tasas de error diagnóstico y una mejora significativa en la comunicación con los médicos tratantes. Se presenta una revisión temática que abarca las características esenciales del informe estructurado contextualizado, los argumentos a favor y en contra de este, los pasos recomendados para su implementación y las oportunidades de mejora hacia el futuro.


Structured reporting in radiology fulfill three fundamental characteristics: they have a uniform structure that answers a clinical question, they are the product of standardized checklists or of knowledge trees previously arranged with multidisciplinary clinical teams, and they are incorporated in option-selection boxes available in electronic reporting systems. Among the main advantages of migrating towards structured reporting are the uniformity and high quality of the report, the increase in intra and interobserver concordance, as well as the reduction of the diagnostic error rates and a significant improvement in communication with the clinical practitioner. This thematic review covers the essential characteristics of the structured report, the arguments for and against it, the recommended steps for its implementation, and the future opportunities for improvement.


Assuntos
Humanos , Sistemas de Informação em Radiologia , Informática Médica , Diagnóstico por Computador
10.
Neuroimage ; 153: 283-292, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28389382

RESUMO

High-density speckle contrast optical tomography (SCOT) utilizing tens of thousands of source-detector pairs, was developed for in vivo imaging of blood flow in small animals. The reduction in cerebral blood flow (CBF) due to local ischemic stroke in a mouse brain was transcanially imaged and reconstructed in three dimensions. The reconstructed volume was then compared with corresponding magnetic resonance images demonstrating that the volume of reduced CBF agrees with the infarct zone at twenty-four hours.


Assuntos
Isquemia Encefálica/diagnóstico por imagem , Córtex Cerebral/irrigação sanguínea , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Óptica/métodos , Algoritmos , Animais , Isquemia Encefálica/fisiopatologia , Córtex Cerebral/fisiopatologia , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Camundongos Endogâmicos C57BL , Processamento de Sinais Assistido por Computador , Acidente Vascular Cerebral/fisiopatologia
11.
Rev Med Chil ; 144(1): 102-7, 2016 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-26998988

RESUMO

The career of Medicine at the Pontificia Universidad Católica de Chile was established from the beginning (1929), with a classical Flexner curriculum design. In seven years, the career is divided in three cycles: basic sciences, clinics and internship. It obtained Chilean accreditation and fulfilled American Association of Medical Colleges accreditation requirements. Changes in the Chilean epidemiological profile and health system, and new teaching methods in medicine, stimulated a process of deep curricular analysis, identifying strengths and weaknesses of the medical career. The curricular strengths were well-developed scientific and clinical components, fully committed students and faculties, well defined learning objectives and excellent clinical campuses. Curricular weaknesses included a poor vertical and horizontal integration, few student centered methodologies and a weak emphasis concerning doctor’s professionalism. Subsequently, the whole community of teachers, students and medical educators worked on the design of a new curriculum, establishing a new graduate profile and designed it oriented by learning objectives, of six years of duration, with an optimized course sequence that melds basic science and clinical concepts, with strong emphasis on humanities and professionalism. It prioritizes an early contact with patients from the first year and expands teaching methods. The main objective of this process was to achieve a new curriculum with an integrative structure. This was implemented in 2015 with an approved protocol to evaluate the outcomes.


Assuntos
Currículo/normas , Educação de Graduação em Medicina/normas , Chile , Educação Baseada em Competências , Currículo/tendências , Educação de Graduação em Medicina/tendências , Avaliação Educacional , Humanos , Estudantes de Medicina
12.
Biomed Opt Express ; 6(8): 2865-76, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26309751

RESUMO

Laser speckle contrast imaging (LSCI) has emerged as a valuable tool for cerebral blood flow (CBF) imaging. We present a multi-exposure laser speckle imaging (MESI) method which uses a high-frame rate acquisition with a negligible inter-frame dead time to mimic multiple exposures in a single-shot acquisition series. Our approach takes advantage of the noise-free readout and high-sensitivity of a complementary metal-oxide-semiconductor (CMOS) single-photon avalanche diode (SPAD) array to provide real-time speckle contrast measurement with high temporal resolution and accuracy. To demonstrate its feasibility, we provide comparisons between in vivo measurements with both the standard and the new approach performed on a mouse brain, in identical conditions.

13.
Biomed Opt Express ; 5(8): 2769-84, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25136500

RESUMO

We introduce a new, non-invasive, diffuse optical technique, speckle contrast optical spectroscopy (SCOS), for probing deep tissue blood flow using the statistical properties of laser speckle contrast and the photon diffusion model for a point source. The feasibility of the method is tested using liquid phantoms which demonstrate that SCOS is capable of measuring the dynamic properties of turbid media non-invasively. We further present an in vivo measurement in a human forearm muscle using SCOS in two modalities: one with the dependence of the speckle contrast on the source-detector separation and another on the exposure time. In doing so, we also introduce crucial corrections to the speckle contrast that account for the variance of the shot and sensor dark noises.

14.
Biomed Opt Express ; 5(4): 1275-89, 2014 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24761306

RESUMO

A novel tomographic method based on the laser speckle contrast, speckle contrast optical tomography (SCOT) is introduced that allows us to reconstruct three dimensional distribution of blood flow in deep tissues. This method is analogous to the diffuse optical tomography (DOT) but for deep tissue blood flow. We develop a reconstruction algorithm based on first Born approximation to generate three dimensional distribution of flow using the experimental data obtained from tissue simulating phantoms.

15.
Stroke ; 45(5): 1453-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24676774

RESUMO

BACKGROUND AND PURPOSE: Several lines of evidence support the involvement of mannose-binding lectin (MBL) in stroke brain damage. The lectin pathway of the complement system facilitates thrombin activation and clot formation under certain experimental conditions. In the present study, we examine whether MBL promotes thrombosis after ischemia/reperfusion and influences the course and prognosis of ischemic stroke. METHODS: Middle cerebral artery occlusion/reperfusion was performed in MBL-deficient (n=85) and wild-type (WT; n=83) mice, and the brain lesion was assessed by MRI at days 1 and 7. Relative cerebral blood flow was monitored up to 6 hours after middle cerebral artery occlusion with laser speckle contrast imaging. Fibrin(ogen) was analyzed in the brain vasculature and plasma, and the effects of thrombin inhibitor argatroban were evaluated to assess the role of MBL in thrombin activation. RESULTS: Infarct volumes and neurological deficits were smaller in MBL knockout mice than in WT mice. Relative cerebral blood flow values during middle cerebral artery occlusion and at reperfusion were similar in both groups, but decreased during the next 6 hours in the WT group only. Also, the WT mice showed more fibrin(ogen) in brain vessels and a better outcome after argatroban treatment. In contrast, argatroban did not improve the outcome in MBL knockout mice. CONCLUSIONS: MBL promotes brain damage and functional impairment after brain ischemia/reperfusion in mice. These effects are secondary to intravascular thrombosis and impaired relative cerebral blood flow during reperfusion. Argatroban protects WT mice, but not MBL knockout mice, emphasizing a role of MBL in local thrombus formation in acute ischemia/reperfusion.


Assuntos
Isquemia Encefálica/fisiopatologia , Infarto da Artéria Cerebral Média/fisiopatologia , Lectina de Ligação a Manose/fisiologia , Traumatismo por Reperfusão/fisiopatologia , Trombose/etiologia , Animais , Antitrombinas/administração & dosagem , Arginina/análogos & derivados , Isquemia Encefálica/genética , Isquemia Encefálica/metabolismo , Circulação Cerebrovascular/genética , Modelos Animais de Doenças , Fibrinogênio/antagonistas & inibidores , Fibrinogênio/metabolismo , Infarto da Artéria Cerebral Média/genética , Infarto da Artéria Cerebral Média/metabolismo , Imageamento por Ressonância Magnética , Masculino , Lectina de Ligação a Manose/deficiência , Lectina de Ligação a Manose/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microcirculação/genética , Ácidos Pipecólicos/administração & dosagem , Traumatismo por Reperfusão/genética , Traumatismo por Reperfusão/metabolismo , Sulfonamidas , Trombose/genética
16.
Rev. chil. neuro-psiquiatr ; 39(2): 121-31, abr.-jun. 2001. tab, graf
Artigo em Espanhol | LILACS | ID: lil-295289

RESUMO

Con el objetivo de mejorar la calidad de la atención secundaria en psicoterapia en el consultorio externo del Instituto Psiquiátrico José Horwitz B., se evaluó el Manual de Psicoterapia Dinámica de Strupp y Binder para entrenar a terapeutas inexpertos. Ocho terapeutas estuvieron expuestos a: 1) un período de formación general (un año de preentrenamiento), 2) 8 seminarios teóricos con el manual y sesiones de observación de videos de terapias de terapeutas expertos, 3) grupos de supervisión (material y videos) y 4) la monitorización de la terapia por un observador externo que, a su vez, era un terapeuta inexperto. El proceso de aprendizaje se evaluó a través de las Escalas Vanderbilt de indicadores Negativos y la Escala de Estrategias Terapéuticas, las que también se usaron como herramientas de aprendizaje. De 27 pacientes evaluados para recibir la psicoterapia (de 20-25 sesiones de duración) sólo 1/3 terminó la terapia. Las características y resultados de los pacientes, los rasgos de los terapeutas, el proceso de supervisión y aprendizaje fueron evaluados con las Escalas Howard-Orlinsky y la Evaluación Cualitativa de Lincoln y Guba. Los resultados mostraton una mejoría estadísticamente significativa en los 9 pacientes que terminaron la terapia. Las Escalas Vanderbilt, evaluadas por jueces independientes, mostraron que los terapeutas noveles no adhirieron a las estrategias específicas del manual; las escalas de supervisión no dieron cuenta del aprendizaje de los terapeutas en el trabajo con herramientas psicodinámicas básicas. No obstante, los puntajes totales en las escalas de supervisión mostraron un incremento estadísticamente significativo en el proceso de aprendizaje (t=2,9 p<0,05 pre-post training; t= 4,7 p<0,01 antes y durante el proceso). El análisis de los resultados muestra al manual (y al programa de entrenamiento asociado) como un catalizador el entrenamiento en psicoterapia, especialmente en lo que se refiere a la incorporación de aspectos interaccionales del acto psicoterapéutico


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Psicoterapia/educação , Manual de Referência , Padrões de Prática Médica , Psicometria/educação , Psicoterapia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA