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2.
Nat Commun ; 12(1): 211, 2021 01 11.
Artículo en Inglés | MEDLINE | ID: mdl-33431878

RESUMEN

Graphene active sensors have demonstrated promising capabilities for the detection of electrophysiological signals in the brain. Their functional properties, together with their flexibility as well as their expected stability and biocompatibility have raised them as a promising building block for large-scale sensing neural interfaces. However, in order to provide reliable tools for neuroscience and biomedical engineering applications, the maturity of this technology must be thoroughly studied. Here, we evaluate the performance of 64-channel graphene sensor arrays in terms of homogeneity, sensitivity and stability using a wireless, quasi-commercial headstage and demonstrate the biocompatibility of epicortical graphene chronic implants. Furthermore, to illustrate the potential of the technology to detect cortical signals from infra-slow to high-gamma frequency bands, we perform proof-of-concept long-term wireless recording in a freely behaving rodent. Our work demonstrates the maturity of the graphene-based technology, which represents a promising candidate for chronic, wide frequency band neural sensing interfaces.


Asunto(s)
Encéfalo/fisiología , Grafito/química , Tecnología Inalámbrica , Animales , Conducta Animal , Ritmo Gamma/fisiología , Ensayo de Materiales , Ratas Long-Evans , Procesamiento de Señales Asistido por Computador , Sueño/fisiología , Factores de Tiempo , Transistores Electrónicos
3.
Actas Dermosifiliogr (Engl Ed) ; 109(8): 712-721, 2018 Oct.
Artículo en Inglés, Español | MEDLINE | ID: mdl-30293553

RESUMEN

BACKGROUND AND OBJECTIVES: Amputation is the conventional treatment for malignant subungual tumors (MSUTs), namely, subungual squamous cell carcinoma (SUSCC) and subungual melanoma (SUM). Functional surgery consisting of wide local excision (WLE) of the nail unit can preserve function without modifying prognosis in such cases. We present a series of MSUTs treated with WLE of the nail unit, describe the technique, and review its indications. MATERIAL AND METHODS: Retrospective observational study of MSUTs treated with WLE of the nail unit between 2008 and 2017. The technique consisted of en bloc supraperiosteal excision of the nail unit with a margin of 5mm followed by repair with a full-thickness graft. RESULTS: Eleven MSUTs were treated in the study period: 7 SUMs (4 in situ; mean thickness, 1.17mm; range, 0-4mm) and 4 SUSCCs (mean thickness, 3.4mm; range, 1.6-6mm). WLE of the nail unit was performed in 9 patients and amputation in 2 patients with invasive SUM. Mean follow-up was 39 months (range, 12-96 months) and no local or regional recurrences were detected. One of the 2 patients who underwent amputation developed metastasis to the brain and died. In our review of the literature, we identified 5 series of patients with SUSCC treated with WLE of the nail unit (105 patients) and 14 series of patients with SUM (243 patients). Based on an analysis of these cases and ours, it would appear that WLE of the nail unit is associated with a very low rate of local recurrence (<7%) and offers better functional and cosmetic outcomes than amputation. CONCLUSIONS: WLE of the nail unit is the treatment of choice for SUSCC without bone involvement and for thin noninvasive SUM (Breslow depth <1mm). It is also feasible in intermediate-thickness SUMs when detailed histologic examination of the margins confirms complete resection. Amputation, by contrast, is the treatment of choice for SUSCCs with bone involvement, very thick SUMs (>4mm), and recurrent tumors.


Asunto(s)
Carcinoma de Células Escamosas/cirugía , Melanoma/cirugía , Enfermedades de la Uña/cirugía , Tratamientos Conservadores del Órgano/métodos , Neoplasias Cutáneas/cirugía , Anciano , Anciano de 80 o más Años , Amputación Quirúrgica , Femenino , Dedos/cirugía , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Retrospectivos , Trasplante de Piel , Dedos del Pie/cirugía , Resultado del Tratamiento
5.
ACS Appl Mater Interfaces ; 6(16): 13909-16, 2014 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-25029037

RESUMEN

The modification of the diamond surface with organic molecules is a crucial aspect to be considered for any bioapplication of this material. There is great interest in broadening the range of linker molecules that can be covalently bound to the diamond surface. In the case of protein immobilization, the hydropathicity of the surface has a major influence on the protein conformation and, thus, on the functionality of proteins immobilized at surfaces. For electrochemical applications, particular attention has to be devoted to avoid that the charge transfer between the electrode and the redox center embedded in the protein is hindered by a thick insulating linker layer. This paper reports on the grafting of 6-phosphonohexanoic acid on OH-terminated diamond surfaces, serving as linkers to tether electroactive proteins onto diamond surfaces. X-ray photoelectron spectroscopy (XPS) confirms the formation of a stable layer on the surface. The charge transfer between electroactive molecules and the substrate is studied by electrochemical characterization of the redox activity of aminomethylferrocene and cytochrome c covalently bound to the substrate through this linker. Our work demonstrates that OH-terminated diamond functionalized with 6-phosphonohexanoic acid is a suitable platform to interface redox-proteins, which are fundamental building blocks for many bioelectronics applications.


Asunto(s)
Diamante/química , Electrodos , Organofosfonatos/química , Citocromos c/química , Espectroscopía de Fotoelectrones
6.
J Community Genet ; 4(3): 321-34, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23904211

RESUMEN

Dissemination of knowledge in genetics to be applied in medicine has created a growing need for capacity building in health care workers. The CAPABILITY ARGENTINA outreach project protocol was designed as a model to introduce genetics in areas without genetic services. Our aim was for genetic health care to become part of primary care in an Argentine province lacking genetic services. The program was innovative as professionals from the referral center (Garrahan Hospital S.A.M.I.C.) traveled to remote areas to train professionals through problem-based education. A logical framework was designed for a local needs assessment. Teaching materials (Powerpoint presentations, printed syllabus, and CD) and a web page were developed. A demonstration project was carried out in the Province of Chaco, Argentina. A total of 485 health workers were trained. The number of consultations increased significantly in participating areas comparing before and after the training period. To support this increase, a complementary project was set up from a public hospital sponsored from within Argentina to build a cytogenetic laboratory in the capital of the Province of Chaco. The model was improved for reproduction in other areas in Argentina. CAPABILITY ARGENTINA is a capacity building model for training of primary care professionals in genetics that may be applied to other medical specialties. The outcomes of the programme have a direct impact on clinical practice.

7.
J Neural Eng ; 10(4): 046019, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23883543

RESUMEN

OBJECTIVE: Fine touch sensing relies on peripheral-to-central neurotransmission of somesthetic percepts, as well as on active motion policies shaping tactile exploration. This paper presents a novel neuroengineering framework for robotic applications based on the multistage processing of fine tactile information in the closed action-perception loop. APPROACH: The integrated system modules focus on (i) neural coding principles of spatiotemporal spiking patterns at the periphery of the somatosensory pathway, (ii) probabilistic decoding mechanisms mediating cortical-like tactile recognition and (iii) decision-making and low-level motor adaptation underlying active touch sensing. We probed the resulting neural architecture through a Braille reading task. MAIN RESULTS: Our results on the peripheral encoding of primary contact features are consistent with experimental data on human slow-adapting type I mechanoreceptors. They also suggest second-order processing by cuneate neurons may resolve perceptual ambiguities, contributing to a fast and highly performing online discrimination of Braille inputs by a downstream probabilistic decoder. The implemented multilevel adaptive control provides robustness to motion inaccuracy, while making the number of finger accelerations covariate with Braille character complexity. The resulting modulation of fingertip kinematics is coherent with that observed in human Braille readers. SIGNIFICANCE: This work provides a basis for the design and implementation of modular neuromimetic systems for fine touch discrimination in robotics.


Asunto(s)
Biorretroalimentación Psicológica/instrumentación , Biorretroalimentación Psicológica/fisiología , Biomimética/instrumentación , Mecanorreceptores/fisiología , Mecanotransducción Celular/fisiología , Robótica/instrumentación , Tacto/fisiología , Simulación por Computador , Diseño de Equipo , Análisis de Falla de Equipo , Retroalimentación Fisiológica/fisiología , Humanos , Modelos Biológicos , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Procesamiento de Señales Asistido por Computador/instrumentación
8.
Med Intensiva ; 37(4): 259-83, 2013 May.
Artículo en Español | MEDLINE | ID: mdl-23507335

RESUMEN

Since allogeneic blood transfusion (ABT) is not harmless, multiple alternatives to ABT (AABT) have emerged, though there is great variability in their indications and appropriate use. This variability results from the interaction of a number of factors, including the specialty of the physician, knowledge and preferences, the degree of anemia, transfusion policy, and AABT availability. Since AABTs are not harmless and may not meet cost-effectiveness criteria, such variability is unacceptable. The Spanish Societies of Anesthesiology (SEDAR), Hematology and Hemotherapy (SEHH), Hospital Pharmacy (SEFH), Critical Care Medicine (SEMICYUC), Thrombosis and Hemostasis (SETH) and Blood Transfusion (SETS) have developed a Consensus Document for the proper use of AABTs. A panel of experts convened by these 6 Societies have conducted a systematic review of the medical literature and have developed the 2013 Seville Consensus Document on Alternatives to Allogeneic Blood Transfusion, which only considers those AABT aimed at decreasing the transfusion of packed red cells. AABTs are defined as any pharmacological or non-pharmacological measure aimed at decreasing the transfusion of red blood cell concentrates, while preserving patient safety. For each AABT, the main question formulated, positively or negatively, is: « Does this particular AABT reduce the transfusion rate or not?¼ All the recommendations on the use of AABTs were formulated according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) methodology.


Asunto(s)
Transfusión Sanguínea/normas , Terapias Complementarias , Humanos , Seguridad del Paciente , Procedimientos Quirúrgicos Operativos
9.
Rev Esp Anestesiol Reanim ; 60(5): 263.e1-263.e25, 2013 May.
Artículo en Español | MEDLINE | ID: mdl-23415109

RESUMEN

Since allogeneic blood transfusion (ABT) is not harmless, multiple alternatives to ABT (AABT) have emerged, though there is great variability in their indications and appropriate use. This variability results from the interaction of a number of factors, including the specialty of the physician, knowledge and preferences, the degree of anemia, transfusion policy, and AABT availability. Since AABTs are not harmless and may not meet cost-effectiveness criteria, such variability is unacceptable. The Spanish Societies of Anesthesiology (SEDAR), Hematology and Hemotherapy (SEHH), Hospital Pharmacy (SEFH), Critical Care Medicine (SEMICYUC), Thrombosis and Hemostasis (SETH) and Blood Transfusion (SETS) have developed a Consensus Document for the proper use of AABTs. A panel of experts convened by these 6 Societies have conducted a systematic review of the medical literature and have developed the 2013 Seville Consensus Document on Alternatives to Allogeneic Blood Transfusion, which only considers those AABT aimed at decreasing the transfusion of packed red cells. AABTs are defined as any pharmacological or non-pharmacological measure aimed at decreasing the transfusion of red blood cell concentrates, while preserving patient safety. For each AABT, the main question formulated, positively or negatively, is: "Does this particular AABT reduce the transfusion rate or not?" All the recommendations on the use of AABTs were formulated according to the Grades of Recommendation Assessment, Development and Evaluation (GRADE) methodology.


Asunto(s)
Procedimientos Médicos y Quirúrgicos sin Sangre/normas , Humanos , Guías de Práctica Clínica como Asunto
12.
Int J Neural Syst ; 21(5): 385-401, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21956931

RESUMEN

This work evaluates the capability of a spiking cerebellar model embedded in different loop architectures (recurrent, forward, and forward&recurrent) to control a robotic arm (three degrees of freedom) using a biologically-inspired approach. The implemented spiking network relies on synaptic plasticity (long-term potentiation and long-term depression) to adapt and cope with perturbations in the manipulation scenario: changes in dynamics and kinematics of the simulated robot. Furthermore, the effect of several degrees of noise in the cerebellar input pathway (mossy fibers) was assessed depending on the employed control architecture. The implemented cerebellar model managed to adapt in the three control architectures to different dynamics and kinematics providing corrective actions for more accurate movements. According to the obtained results, coupling both control architectures (forward&recurrent) provides benefits of the two of them and leads to a higher robustness against noise.


Asunto(s)
Potenciales de Acción/fisiología , Cerebelo/fisiología , Modelos Neurológicos , Plasticidad Neuronal/fisiología , Robótica , Fenómenos Biomecánicos , Cerebelo/anatomía & histología , Simulación por Computador , Humanos , Red Nerviosa , Redes Neurales de la Computación , Neuronas/fisiología , Transmisión Sináptica/fisiología
14.
Phys Rev Lett ; 106(19): 196103, 2011 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-21668176

RESUMEN

The hydrophobic interaction of surfaces with water is a well-known phenomenon, but experimental evidence of its influence on biosensor devices has been lacking. In this work we investigate diamond field-effect devices, reporting on Hall effect experiments and complementary simulations of the interfacial potential at the hydrogen-terminated diamond/aqueous electrolyte interface. The interfacial capacitance, derived from the gate-dependent Hall carrier concentration, can be modeled only when considering the hydrophobic nature of this surface and its influence on the structure of interfacial water. Our work demonstrates how profoundly the performance of potentiometric biosensor devices can be affected by their surfaces' hydrophobicity.


Asunto(s)
Técnicas Biosensibles/instrumentación , Diamante/química , Electrólitos/química , Modelos Químicos , Agua/química , Interacciones Hidrofóbicas e Hidrofílicas , Programas Informáticos , Propiedades de Superficie
16.
Clin Exp Dermatol ; 35(3): 311-7, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19874323

RESUMEN

BACKGROUND: Studies on the reliability of teledermatology have shown considerable variability in results. Only one study has compared asynchronous and synchronous methods. OBJECTIVES: This report describes DERMATEL, a prospective, randomized diagnostic-concordance study that sought to evaluate the relative advantages, in terms of reliability, of two remote consultation techniques. METHODS: Patients referred by 18 general practitioners were randomized (4 : 4 : 2) to three study groups: store and forward (SF), hybrid videoconferencing-SF (VC-SF), and a control group. In total, 457 patients were assigned: 192 to the SF group, 176 to the VC-SF group and 89 to the control group. High-quality still images were used throughout, with additional use of standard web-camera (webcam) videoconferencing in the VC-SF group. All patients were also seen by the same dermatologist in a face-to-face (FTF) consultation, considered the practical reference standard. Two different dermatologists assessed concordances between the teledermatology and FTF consultations. RESULTS: There were no significant differences in age, gender or diagnostic category between the three groups, and the images (82%), clinical history (91%) and diagnostic confidence (89%) were high-quality. Online management was possible for 70% of cases. Agreement between teledermatology and the FTF consultation was high for both diagnosis (> 0.85) and treatment (> 0.78). Concordance in diagnosis was influenced by image quality (P < 0.001), confidence in diagnosis (P < 0.001) and need for conventional consultation (P < 0.001), rather than by quality of clinical history (P = 0.58) or method of teleconsultation (P = 0.340). CONCLUSIONS: Intraobserver reliability is very high in teledermatology. When history taking and training in digital photography are standardised, a hybrid system with audio is no better than SF alone.


Asunto(s)
Dermatología/métodos , Enfermedades de la Piel/diagnóstico , Telemedicina/métodos , Comunicación por Videoconferencia/normas , Adolescente , Adulto , Anciano , Niño , Preescolar , Dermatología/normas , Femenino , Humanos , Lactante , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Satisfacción del Paciente , Estudios Prospectivos , Telemedicina/normas , Adulto Joven
17.
Actas Dermosifiliogr ; 99(7): 506-22, 2008 Sep.
Artículo en Español | MEDLINE | ID: mdl-18682163

RESUMEN

Telemedicine refers to the use of telecommunications technology to provide health care and medical information. The practice of medicine--and dermatology in particular--is undergoing a great upheaval due to advances in information technology. This article briefly reviews the origin, development, applications, benefits, methodology, and components of telemedicine. Specifically, we will analyze the types and applications of teledermatology, paying particular attention to technical, organizational, and legal aspects.


Asunto(s)
Dermatología , Telemedicina , Dermatología/métodos , Dermatología/tendencias , Predicción , Salud Global , Servicios de Salud/provisión & distribución , Accesibilidad a los Servicios de Salud , Humanos , Difusión de la Información , Internet , Educación del Paciente como Asunto/métodos , Consulta Remota , Factores Socioeconómicos , Telemedicina/clasificación , Telemedicina/instrumentación , Telemedicina/legislación & jurisprudencia , Telemedicina/métodos , Telemedicina/organización & administración , Telemedicina/tendencias , Teléfono , Comunicación por Videoconferencia
18.
Proc Natl Acad Sci U S A ; 105(8): 2842-7, 2008 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-18287007

RESUMEN

The hydrophobic effect, i.e., the poor solvation of nonpolar parts of molecules, plays a key role in protein folding and more generally for molecular self-assembly and aggregation in aqueous media. The perturbation of the water structure accounts for many aspects of protein hydrophobicity. However, to what extent the dispersion interaction between molecular entities themselves contributes has remained unclear. This is so because in peptide folding interactions and structural changes occur on all length scales and make disentangling various contributions impossible. We address this issue both experimentally and theoretically by looking at the force necessary to peel a mildly hydrophobic single peptide molecule from a flat hydrophobic diamond surface in the presence of water. This setup avoids problems caused by bubble adsorption, cavitation, and slow equilibration that complicate the much-studied geometry with two macroscopic surfaces. Using atomic-force spectroscopy, we determine the mean desorption force of a single spider-silk peptide chain as F = 58 +/- 8 pN, which corresponds to a desorption free energy of approximately 5 k(B)T per amino acid. Our all-atomistic molecular dynamics simulation including explicit water correspondingly yields the desorption force F = 54 +/- 15 pN. This observation demonstrates that standard nonpolarizable force fields used in classical simulations are capable of resolving the fine details of the hydrophobic attraction of peptides. The analysis of the involved energetics shows that water-structure effects and dispersive interactions give contributions of comparable magnitude that largely cancel out. It follows that the correct modeling of peptide hydrophobicity must take the intimate coupling of solvation and dispersive effects into account.


Asunto(s)
Modelos Químicos , Péptidos/química , Péptidos/metabolismo , Seda/química , Arañas/química , Adsorción , Secuencia de Aminoácidos , Animales , Simulación por Computador , Interacciones Hidrofóbicas e Hidrofílicas , Datos de Secuencia Molecular , Solubilidad , Espectrofotometría Atómica , Propiedades de Superficie
19.
Arch Soc Esp Oftalmol ; 81(7): 401-4, 2006 Jul.
Artículo en Español | MEDLINE | ID: mdl-16888693

RESUMEN

PURPOSE: To determine the effects of phothodynamic therapy using verteporfin in the treatment of patients with retinal angiomatous proliferation (RAP) and the incidence of this retinal disease in our area. METHODS: We performed a retrospective study of 11 cases of RAP who were treated with photodynamic therapy using verteporfin (PDT). RESULTS: The incidence of RAP in the group of eyes with minimally classic or occult subfoveal choroidal neovascularization was 8%. The mean follow-up time after treatment was 15 months. The visual acuity improved in 3, remained the same in 4, and decreased in 4. In 4 patients, angiomatous lesions were observed in both eyes. CONCLUSIONS: There is no method proven to be effective for the treatment of retinal angiomatous proliferation. Our results suggest that PDT may be useful therapy in patients with RAP as it appeared to reduce the risk of visual loss.


Asunto(s)
Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Porfirinas/uso terapéutico , Neovascularización Retiniana/tratamiento farmacológico , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Estudios Retrospectivos , Verteporfina
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