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










Intervalo de año de publicación
1.
Edumecentro ; 152023.
Artículo en Español | LILACS | ID: biblio-1448145

RESUMEN

Fundamento: el nivel académico superior en la atención primaria de salud tiene importante repercusión en la formación de los futuros profesionales, por lo que es necesario atender las necesidades de superación pedagógica con vistas a perfeccionar la competencia y desempeño en esta tarea. Objetivo: diagnosticar las necesidades de superación pedagógica en médicos de la atención primaria de salud pertenecientes al Policlínico Universitario "Juana Naranjo León" de Sancti Spíritus, Cuba. Métodos: se realizó un estudio observacional, descriptivo, de corte transversal. Su contexto fueron los escenarios docentes asistenciales del Policlínico Universitario "Juana Naranjo León" de Sancti Spíritus, en el período comprendido de 2020-2021. Para fundamentar la investigación se utilizaron métodos teóricos (análisis-síntesis e inducción-deducción) y empíricos (revisión documental y cuestionario). Se emplearon procedimientos de estadística descriptiva (frecuencia absoluta y relativa), para el análisis e interpretación de los resultados. Resultados: se evidenció limitada preparación docente e insuficiente desempeño en la formación educativa para garantizar la calidad del proceso enseñanza aprendizaje, a partir de la baja categorización y el escaso número de actividades e investigaciones de corte académico. Conclusiones: el estudio realizado permitió conocer el estado actual de los conocimientos y preparación docente-metodológica del claustro de la institución en el primer nivel de atención médica. Estos profesionales requieren atención prioritaria para el desempeño formativo, y alcanzar con ello la excelencia en el proceso docente-educativo.


Background: the higher academic level in primary health care has an important impact on the training of future professionals, so it is necessary to meet the needs of pedagogical improvement with a view to improving competence and performance in this task. Objective: to diagnose the needs for pedagogical improvement in PHC doctors belonging to the "Juana Naranjo León" University Polyclinic in Sancti Spíritus, Cuba. Methods: an observational, descriptive, cross-sectional study was carried out. Its context was the teaching assistance scenarios of the "Juana Naranjo León" University Polyclinic in Sancti Spíritus, from 2020 to 2021. Theoretical methods were used to support the research: (analysis-synthesis and induction-deduction) and empirical ones (documentary review and questionnaire). Descriptive statistical procedures (absolute and relative frequency) were used for the analysis and interpretation of the results. Results: limited teaching preparation and insufficient performance in educational training were evidenced to guarantee the quality of the teaching-learning process, taking into account the low categorization and the small number of activities and academic research. Conclusions: the study allowed us to know the current state of knowledge and teaching-methodological preparation of the teaching staff of the institution at the first level of medical care, which require priority attention for training performance, and thereby achieve excellence in the teaching-learning process.


Asunto(s)
Educación Médica , Educación Profesional , Programas de Posgrado en Salud , Capacitación Profesional
2.
Artículo en Español | LILACS, CUMED | ID: biblio-1441611

RESUMEN

Introducción: La creciente necesidad de una piel de aspecto juvenil impulsa innovaciones continuas con procedimientos mínimamente invasivos. El plasma rico en plaquetas autólogo representa una terapéutica regenerativa incluida en el novedoso arsenal de intervenciones que buscan este efecto. Objetivo: Evaluar los resultados de la terapéutica con plasma rico en plaquetas autólogo en pacientes con envejecimiento facial. Métodos: La muestra estuvo constituida por 68 pacientes valorados con la escala para valoración clínica de fotoenvejecimiento cutáneo al inicio del tratamiento. Se sometieron a cuatro sesiones de plasma rico en plaquetas cada 15 días y una sesión adicional a los 3 meses de concluir el tratamiento inicial. Los pacientes fueron seguidos durante 6 meses al cabo de los cuales se volvieron a evaluar con el mismo instrumento. Resultados: Las edades estuvieron comprendidas entre 21 y 73 años con una media de 46,80 años, predominó el sexo femenino (89,9 %). Los resultados significativos en el tratamiento de las arrugas, los surcos, la textura de la piel y las lesiones cutáneas estuvieron relacionados con la mesoterapia con plasma rico en plaquetas. El procedimiento produjo una mejoría valorada a través de la escala para valoración clínica de fotoenvejecimiento cutáneo. Conclusiones: La terapia con plasma rico en plaquetas tiene buenos resultados en el tratamiento de pacientes con envejecimiento facial.


Introduction: The growing need for youthful looking skin drives continued innovations with minimally invasive procedures. Autologous platelet-rich plasma represents a regenerative therapeutic included in the new arsenal of interventions that seek this effect. Objective: Assess the results of platelet-rich plasma therapy in patients with facial aging. Methods: The sample consisted of 68 patients assessed with the scale for the clinical assessment of cutaneous photoaging (SCACPH). They underwent four PRP sessions every 15 days and an additional session 3 months after completing the initial treatment. The patients were followed up for 6 months, after which they were reevaluated which the same instrument. Results: The ages of the patients were between 21 and 73 years with a mean of 46.80 years, the female sex predominated (89.9%). Significant results in the treatment of wrinkles, furrows, and skin texture and skin lesions were related to PRP mesotherapy. The procedure produced an improvement assessed with the SCACPH. Conclusions: Autologous PRP therapy has good results in the treatment of patients with facial aging.


Asunto(s)
Humanos , Rejuvenecimiento/fisiología , Mesoterapia/métodos
3.
Pharmaceutics ; 14(9)2022 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-36145602

RESUMEN

Herein, we report the synthesis of Au nanoparticles (AuNPs) in chitosan (CTS) solution by chemically reducing HAuCl4. CTS was further functionalized with glycidyl methacrylate (chitosan-g-glycidyl methacrylate/AuNP, CTS-g-GMA/AuNP) to improve the mechanical properties for cellular regeneration requirements of CTS-g-GMA/AuNP. Our nanocomposites promote excellent cellular viability and have a positive effect on cytokine regulation in the inflammatory and anti-inflammatory response of skin cells. After 40 days of nanocomposite exposure to a skin wound, we showed that our films have a greater skin wound healing capacity than a commercial film (TheraForm®), and the presence of the collagen allows better cosmetic ave aspects in skin regeneration in comparison with a nanocomposite with an absence of this protein. Electrical percolation phenomena in such nanocomposites were used as guiding tools for the best nanocomposite performance. Our results suggest that chitosan-based Au nanocomposites show great potential for skin wound repair.

4.
Rev Sci Instrum ; 93(1): 013906, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-35104972

RESUMEN

A near-field electrospinning configuration has been developed to fabricate 3D structures by layer-by-layer stacking. The system or experimental setup consists of a high voltage source, a syringe pump, and the electrospinning equipment which has been designed and built. It works with Arduino Uno as a controller for adjusting the procedural parameters through OpenBuilds CONTROL software using a firmware preloaded on the Arduino Uno. The proposed experimental configuration consists of a collinear arrangement between the spinner and the sharp electrode, which move in the XY directions, keeping the same disposition; this arrangement is designed with the aim of manipulating the electric field (EF) and reducing instabilities associated with the process. The displacement speed (DS) and the distance of work adjust automatically to modify nanofiber features, which improves the flexibility of the system. In order to be efficient and set the EF profile, this was simulated using COMSOL Multiphysics® software. Nylon 6,6 polymeric fiber films have been electrospun to evaluate the efficiency of the system setup and the influence of parameters. The fiber morphology is studied by scanning electron microscopy and the chemical structure features are studied by infrared spectroscopy. Parameters such as voltage and DS are studied experimentally and analyzed to determine their effects on the control of fiber deposition. Stacking of up to 15 layers was obtained where the structural characteristics notably depend on the operating parameters.

5.
Rev. Finlay ; 11(4)dic. 2021.
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1406815

RESUMEN

RESUMEN Fundamento: la cirugía plástica ayuda a la mejora de la calidad de vida de las pacientes con cáncer de mama. La reconstrucción mamaria ha evolucionado no solo en las cuestiones estéticas, sino también, a favor de lograr menor morbilidad en las pacientes afectadas. Objetivo: describir los resultados obtenidos con la aplicación de técnicas oncoplásticas en pacientes con cáncer de mama. Método: se realizó un estudio descriptivo de una serie de 41 pacientes en el Hospital Provincial General Camilo Cienfuegos de Sancti Spíritus desde marzo de 2018 hasta octubre de 2020. La muestra incluyó a todas las pacientes intervenidas por cáncer de mama a las que se realizaron técnicas oncológicas conservadoras y radicales, así como, cirugía plástica. Fueron analizadas variables demográficas, clínicas y terapéuticas. Se utilizaron los procedimientos aritméticos y tabulares de la estadística descriptiva. Se mostraron las variables cuantitativas como promedios y desviación estándar, los datos cualitativos como frecuencias y porcentajes. Resultados: la edad media fue de 45 años, con una mínima de 26 años y una máxima de 67. En las pacientes sin deformidad mamaria previa se aplicaron tratamientos radicales, conservadores, reconstrucción con cirugía ahorradora de piel y mastoplastias con mínimas incisiones. En las pacientes con deformidades mayores el tratamiento que predominó fue conservador y las reconstrucciones con mastoplastias. Los estadios tumorales que prevalecieron fueron los T2N1M0 y T1N1M0. El mayor número de complicaciones se observó en las pacientes sometidas a cirugía ahorradora de piel y en aquellas con tratamientos radicales. Conclusiones: la cirugía oncoplástica es una alternativa de tratamiento quirúrgico que actualmente se emplea con más frecuencia en las pacientes con cáncer de mama. Se obtienen resultados similares a los de la cirugía convencional en cuanto a incidencia de complicaciones, recidivas y muerte.


ABSTRACT Background: plastic surgery helps to improve the quality of life of patients with breast cancer. Breast reconstruction has evolved not only in aesthetic matters, but also in favor of achieving less morbidity in each patient affected. Objective: to describe the results obtained with the application of oncoplastic techniques in patients with breast cancer. Method: a descriptive study of a series of 41 patients was carried out at the Camilo Cienfuegos Provincial General Hospital in Sancti Spíritus from March 2018 to October 2020. The sample included all the patients operated on for breast cancer in which techniques were performed. Conservative and radical oncology, as well as, plastic surgery. Demographic, clinical and therapeutic variables were analyzed. The arithmetic and tabular procedures of descriptive statistics were used. Quantitative variables were shown as means and standard deviation. Qualitative data such as frequencies and percentages. Results: the mean age was 45 years, with a minimum of 26 years and a maximum of 67. In patients without previous breast deformity, radical and conservative treatments, reconstruction with skin-sparing surgery and mastoplasties with minimal incisions were applied. In patients with major deformities, the predominant treatment was conservative and reconstructions with mastoplasties. The tumor stages that prevailed were T2N1M0 and T1N1M0. The highest number of complications was observed in patients undergoing skin-sparing surgery and in those with radical treatments. Conclusions: oncoplastic surgery is an alternative surgical treatment that is currently used more frequently in patients with breast cancer. Similar results are obtained to conventional surgery in terms of incidence of complications, recurrences and death.

6.
Front Neurosci ; 15: 643391, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34220415

RESUMEN

α-synuclein (αSyn) is the main protein component of Lewy bodies, intracellular inclusions found in the brain of Parkinson's disease (PD) patients. Neurotoxic αSyn species are broadly modified post-translationally and, in patients with genetic forms of PD, carry genetically encoded amino acid substitutions. Mutations and C-terminal truncation can increase αSyn oligomerization and fibrillization. Although several genetic mouse models based on αSyn mutations and/or truncations exist, there is still a lack of mouse models for synucleinopathies not relying on overexpression. We report here two synucleinopathy mouse models, which are based on a triple alanine to proline mutation and a C-terminal truncation of αSyn, but do not overexpress the mutant protein when compared to the endogenous mouse protein. We knocked hαSyn TP or hαSynΔ119 (h stands for "human") into the murine αSyn locus. hαSynTP is a structure-based mutant with triple alanine to proline substitutions that favors oligomers, is neurotoxic and evokes PD-like symptoms in Drosophila melanogaster. hαSynΔ119 lacks 21 amino acids at the C-terminus, favors fibrillary aggregates and occurs in PD. Knocking-in of hαSyn TP or hαSynΔ119 into the murine αSyn locus places the mutant protein under the control of the endogenous regulatory elements while simultaneously disrupting the mαSyn gene. Mass spectrometry revealed that hαSyn TP and hαSynΔ119 mice produced 12 and 10 times less mutant protein, compared to mαSyn in wild type mice. We show phenotypes in 1 and 1.5 years old hαSyn TP and hαSynΔ119 mice, despite the lower levels of hαSynTP and hαSynΔ119 expression. Direct comparison of the two mouse models revealed many commonalities but also aspects unique to each model. Commonalities included strong immunoactive state, impaired olfaction and motor coordination deficits. Neither model showed DAergic neuronal loss. Impaired climbing abilities at 1 year of age and a deviant gait pattern at 1.5 years old were specific for hαSynΔ119 mice, while a compulsive behavior was exclusively detected in hαSyn TP mice starting at 1 year of age. We conclude that even at very moderate levels of expression the two αSyn variants evoke measurable and progressive deficiencies in mutant mice. The two transgenic mouse models can thus be suitable to study αSyn-variant-based pathology in vivo and test new therapeutic approaches.

7.
Gac. méd. espirit ; 21(3): 112-121, sept.-dic. 2019. tab, graf
Artículo en Español | LILACS | ID: biblio-1090449

RESUMEN

RESUMEN Fundamento: La técnica del tonel de Schuchardt, está indicada cuando el defecto en el labio compromete del 30-75 % del labio, de localización central y paramedial que afecta bermellón y piel; en este caso se usó el colgajo para reconstruir una lesión tumoral más lateral. La técnica aparece descrita para extraer el tonel de espesor parcial, sin embargo, teniendo en cuenta el margen oncológico recomendado en este caso la excéresis abarcó todo el espesor del labio. Objetivo: Presentar un caso de un paciente con un carcinoma epidermoide del 40 % en el labio inferior intervenido en el Hospital General Camilo Cienfuegos. Presentación del caso: Paciente masculino de 43 años de edad tratado durante un año por queilitis actínica, portador de una lesión exofítica, infiltrante que ocupaba el 40 % del labio inferior. Se estableció como impresión diagnóstica un carcinoma epidermoide y se decidió el tratamiento quirúrgico. Atendiendo a las características individuales del paciente y a las de la lesión, se eligió la técnica del tonel descrita por Schuchardt. Conclusiones: Las lesiones malignas de los labios pueden incidir enmascaradas por el cuadro clínico de lesiones premalignas como la queilitis actínica por lo que es importante mantener un seguimiento estrecho de estos casos. Al aplicar el método clínico puede decidirse la intervención quirúrgica con diagnóstico presuntivo de carcinoma epidermoide, deben respetarse entonces los márgenes oncológicos recomendados. La técnica del tonel inicialmente descrita para pérdidas de tejidos mediales y paramediales del labio, de espesor parcial puede emplearse en defectos de localización más lateral y de espesor total con resultados satisfactorios.


ABSTRACT Background: The barrel of Schuchardt technique, is indicated when the defect in the lip compromises 30-75 % of it, from central to paramedial location which affects both, vermilion and skin; in this case, the flap was used for rebuilding a more lateral tumor lesion. The technique is described to extract the partial thickness barrel; however, taking into account the oncological margin recommended in this case, the hysteresis covered the entire thickness of the lip. Objective: To present a case of a patient with 40 % squamous cell carcinoma in the lower lip intervened at Camilo Cienfuegos General Hospital. Case report: A 43-year-old male patient treated for a year having actinic cheilitis, with an infiltrated exophytic lesion, occupying 40 % of the lower lip. A squamous cell carcinoma was diagnosed, so surgical treatment. Based on the individual characteristics of the patient and those of the lesion, the barrel technique described by Schuchardt was chosen. Conclusions: Malignant lesions of the lips can affect masked by the clinical picture of premalignant lesions such as actinic cheilitis, so it is important to keep a close follow-up of these cases. When applying the clinical method, the surgical intervention with presumptive diagnosis of squamous cell carcinoma can be decided, then the recommended oncological margins must be respected. The barrel technique initially described for losses of medial and paramedial tissues of the lip, of partial thickness can be used in defects of more lateral location and of total thickness with satisfactory results.


Asunto(s)
Neoplasias de los Labios/cirugía , Carcinoma de Células Escamosas/cirugía , Queilitis/cirugía
8.
Gac. méd. espirit ; 21(3): 112-121, sept.-dic. 2019. tab, graf
Artículo en Español | CUMED | ID: cum-76882

RESUMEN

RESUMEN Fundamento: La técnica del tonel de Schuchardt, está indicada cuando el defecto en el labio compromete del 30-75 % del labio, de localización central y paramedial que afecta bermellón y piel; en este caso se usó el colgajo para reconstruir una lesión tumoral más lateral. La técnica aparece descrita para extraer el tonel de espesor parcial, sin embargo, teniendo en cuenta el margen oncológico recomendado en este caso la excéresis abarcó todo el espesor del labio. Objetivo: Presentar un caso de un paciente con un carcinoma epidermoide del 40 % en el labio inferior intervenido en el Hospital General Camilo Cienfuegos. Presentación del caso: Paciente masculino de 43 años de edad tratado durante un año por queilitis actínica, portador de una lesión exofítica, infiltrante que ocupaba el 40 % del labio inferior. Se estableció como impresión diagnóstica un carcinoma epidermoide y se decidió el tratamiento quirúrgico. Atendiendo a las características individuales del paciente y a las de la lesión, se eligió la técnica del tonel descrita por Schuchardt. Conclusiones: Las lesiones malignas de los labios pueden incidir enmascaradas por el cuadro clínico de lesiones premalignas como la queilitis actínica por lo que es importante mantener un seguimiento estrecho de estos casos. Al aplicar el método clínico puede decidirse la intervención quirúrgica con diagnóstico presuntivo de carcinoma epidermoide, deben respetarse entonces los márgenes oncológicos recomendados. La técnica del tonel inicialmente descrita para pérdidas de tejidos mediales y paramediales del labio, de espesor parcial puede emplearse en defectos de localización más lateral y de espesor total con resultados satisfactorios.


ABSTRACT Background: The barrel of Schuchardt technique, is indicated when the defect in the lip compromises 30-75 % of it, from central to paramedial location which affects both, vermilion and skin; in this case, the flap was used for rebuilding a more lateral tumor lesion. The technique is described to extract the partial thickness barrel; however, taking into account the oncological margin recommended in this case, the hysteresis covered the entire thickness of the lip. Objective: To present a case of a patient with 40 % squamous cell carcinoma in the lower lip intervened at Camilo Cienfuegos General Hospital. Case report: A 43-year-old male patient treated for a year having actinic cheilitis, with an infiltrated exophytic lesion, occupying 40 % of the lower lip. A squamous cell carcinoma was diagnosed, so surgical treatment. Based on the individual characteristics of the patient and those of the lesion, the barrel technique described by Schuchardt was chosen. Conclusions: Malignant lesions of the lips can affect masked by the clinical picture of premalignant lesions such as actinic cheilitis, so it is important to keep a close follow-up of these cases. When applying the clinical method, the surgical intervention with presumptive diagnosis of squamous cell carcinoma can be decided, then the recommended oncological margins must be respected. The barrel technique initially described for losses of medial and paramedial tissues of the lip, of partial thickness can be used in defects of more lateral location and of total thickness with satisfactory results.


Asunto(s)
Humanos , Neoplasias de los Labios/cirugía , Carcinoma de Células Escamosas/cirugía , Queilitis/cirugía
9.
Brain Struct Funct ; 224(4): 1609-1625, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-30903359

RESUMEN

Noradrenaline is a neurotransmitter involved in general arousal, selective attention, memory, inflammation, and neurodegeneration. The purpose of this work was to delineate noradrenergic neurons in vivo by T1-weighted MRI with magnetization transfer (MT). In the brainstem of human and mice, MRI identified the locus coeruleus, dorsal motor vagus nucleus, and nucleus tractus solitarius. Given (1) the long T1 and low magnetization transfer ratio for the noradrenergic cell groups compared to other gray matter, (2) significant correlation between MT MRI signal intensity and proton density, and (3) no correlation between magnetization transfer ratio (or R1) and iron, copper, or manganese in human brain, the high MRI signal of the noradrenergic neurons must be attributed to abundant water protons interacting with any T1-shortening paramagnetic ions in active cells rather than to specific T1-shortening molecules. The absence of a high MRI signal from the locus coeruleus of Ear2(-/-) mice lacking noradrenergic neurons confirms that cell bodies of noradrenergic neurons are the source of the bright MRI appearance. The observation of this high signal in DBH(-/-) mice, in 3-week-old mice, and in mice under hyperoxia/hypercapnia/hypoxia together with the general absence of neuromelanin (NM) in noradrenergic neurons of young rodents further excludes that it is due to NM, dopamine ß-hydroxylase, their binding to paramagnetic ions, blood inflow, or hemoglobin. Instead, these findings indicate a high density of water protons whose T1 is shortened by paramagnetic ions as the relevant source of the high MRI signal. In the brain of APP/PS1/Ear2(-/-) mice, a transgenic model of Alzheimer's disease, MRI detected noradrenergic neuron loss in the locus coeruleus. Proton magnetic resonance spectroscopy revealed that a 60-75% reduction of noradrenaline is responsible for a reduction of N-acetylaspartate and glutamate in the hippocampus as well as for a shortening of the water proton T2 in the frontal cortex. These results suggest that a concurrent shortage of noradrenaline in Alzheimer's disease accelerates pathologic processes such as inflammation and neuron loss.


Asunto(s)
Neuronas Adrenérgicas , Encéfalo/anatomía & histología , Encéfalo/diagnóstico por imagen , Locus Coeruleus/anatomía & histología , Locus Coeruleus/diagnóstico por imagen , Imagen por Resonancia Magnética/métodos , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/patología , Animales , Tronco Encefálico/anatomía & histología , Tronco Encefálico/diagnóstico por imagen , Modelos Animales de Enfermedad , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Espectroscopía de Resonancia Magnética , Masculino , Ratones Transgénicos , Relación Señal-Ruido
10.
Materials (Basel) ; 11(1)2018 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-29329275

RESUMEN

The aim of this study is to analyze the properties of a series of polysaccharide composite films, such as apparent density, color, the presence of functional groups, morphology, and thermal stability, as well as the correlation between them and their antimicrobial and optical properties. Natural antioxidants such as anthocyanins (from cranberry; blueberry and pomegranate); betalains (from beetroot and pitaya); resveratrol (from grape); and thymol and carvacrol (from oregano) were added to the films. Few changes in the position and intensity of the FTIR spectra bands were observed despite the low content of extract added to the films. Due to this fact, the antioxidants were extracted and identified by spectroscopic analysis; and they were also quantified using the Folin-Denis method and a gallic acid calibration curve, which confirmed the presence of natural antioxidants in the films. According to the SEM analysis, the presence of natural antioxidants has no influence on the film morphology because the stretch marks and white points that were observed were related to starch presence. On the other hand, the TGA analysis showed that the type of extract influences the total weight loss. The overall interpretation of the results suggests that the use of natural antioxidants as additives for chitosan-starch film preparation has a prominent impact on most of the critical properties that are decisive in making them suitable for food-packing applications.

11.
Polymers (Basel) ; 10(3)2018 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-30966316

RESUMEN

A hybrid nanocomposites based on epoxy reinforced with a combination of 1D and 2D carbon nanomaterials for improving impact resistance are reported. Multi-walled carbon nanotubes and oxidized-multi-walled carbon nanotubes are used as 1D nanoreinforcements, and graphene derivative materials such as graphene oxide and reduced graphene oxide are utilized as 2D nanoreinforcements. In this research, the impact resistance of epoxy matrix reinforced with 1D or 2D and the mixture of both nanomaterials is studied. The research is focused on evaluation of the influence of adding different combinations of nanomaterials into epoxy resin and their Izod impact response. Moreover, fracture surface of nanocomposites is observed by scanning electron microscopy. Images show differences between the surfaces of brittle nature on thermoset epoxy polymer and tough nanocomposites. Synergy created with 1D and 2D nanomaterials produces stable dispersions in the processing, reflected in the interface. The interactions in nanocomposites are evidenced by infrared spectra, principally on the peaks related to oxygenated functional groups present in nanomaterials and absent in polymer matrix. Consequently, an increase of 138% in fracture strength of nanocomposites is exhibited, in comparison to the neat epoxy matrix. In addition, hybrid nanocomposites were synthesized in two different methods to evaluate the influence of manufacturing method on final properties of nanocomposites.

12.
EMBO Mol Med ; 10(1): 32-47, 2018 01.
Artículo en Inglés | MEDLINE | ID: mdl-29208638

RESUMEN

Alzheimer's disease is a devastating neurodegenerative disease eventually leading to dementia. An effective treatment does not yet exist. Here we show that oral application of the compound anle138b restores hippocampal synaptic and transcriptional plasticity as well as spatial memory in a mouse model for Alzheimer's disease, when given orally before or after the onset of pathology. At the mechanistic level, we provide evidence that anle138b blocks the activity of conducting Aß pores without changing the membrane embedded Aß-oligomer structure. In conclusion, our data suggest that anle138b is a novel and promising compound to treat AD-related pathology that should be investigated further.


Asunto(s)
Enfermedad de Alzheimer/tratamiento farmacológico , Péptidos beta-Amiloides/metabolismo , Benzodioxoles/uso terapéutico , Hipocampo/efectos de los fármacos , Pirazoles/uso terapéutico , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/fisiopatología , Péptidos beta-Amiloides/genética , Animales , Benzodioxoles/farmacología , Modelos Animales de Enfermedad , Hipocampo/metabolismo , Hipocampo/fisiopatología , Masculino , Ratones , Ratones Endogámicos C57BL , Plasticidad Neuronal/efectos de los fármacos , Fenotipo , Pirazoles/farmacología , Memoria Espacial/efectos de los fármacos , Transcriptoma/efectos de los fármacos
13.
Int J Mol Sci ; 18(5)2017 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-28475151

RESUMEN

Natural extracts possess several kinds of antioxidants (anthocyanins, betalains, thymol, carvacrol, and resveratrol) that have also demonstrated antimicrobial properties. In order to study these properties, extracts from cranberry, blueberry, beetroot, pomegranate, oregano, pitaya, and resveratrol (from grapes) were obtained. Growth inhibition tests of mesophilic aerobes, coliforms, and fungi were conducted in films prepared from the extracts in accordance with Mexican Official Norms (NOM). Optical properties such as transparency and opacity, mechanical properties, and pH were also analyzed in these materials. The films with beetroot, cranberry, and blueberry extracts demonstrated the best antimicrobial activity against various bacteria and fungi in comparison with unmodified chitosan-starch film. This study shows that the addition of antioxidants improved the antimicrobial performance of these films. It was also found that antimicrobial properties are inherent to the films. These polymers combined with the extracts effectively inhibit or reduce microorganism growth from human and environmental contact; therefore, previous sterilization could be unnecessary in comparison with traditional plastics. The presence of extracts decreased transmittance percentages at 280 and 400 nm, as well as the transparency values, while increasing their opacity values, providing better UV-VIS light barrier properties. Despite diminished glass transition temperatures (Tg), the values obtained are still adequate for food packaging applications.


Asunto(s)
Antiinfecciosos/farmacología , Quitosano/química , Frutas/química , Extractos Vegetales/farmacología , Almidón/química , Antiinfecciosos/síntesis química , Antiinfecciosos/química , Aspergillus/efectos de los fármacos , Enterobacteriaceae/efectos de los fármacos , Fenómenos Mecánicos , Fenómenos Ópticos , Penicillium/efectos de los fármacos , Extractos Vegetales/química
14.
Artículo en Inglés | MEDLINE | ID: mdl-25922685

RESUMEN

Graphite and graphene oxides have been studied amply in the last decade, due to their diverse properties and possible applications. Recently, their functionality as photocatalytic materials in water splitting was reported. Research in these materials is increasing due to their band gap values around 1.8-4 eV, and therefore, these are comparable with other photocatalysts currently used in heterogeneous photocatalytic processes. Thus, this research reports the photocatalytic effectiveness of graphite oxide (GO) and graphene oxide (GEO) in the degradation of 4-chlorophenol (4-CP) in water. Under the conditions defined for this research, 92 and 97% of 4-CP were degraded with GO and GEO respectively, also 97% of total organic carbon was removed. In addition, by-products of 4-CP that produce a yellow solution obtained only using photolysis are eliminated by photocatalyst process with GO and GEO. The degradation of 4-CP was monitored by UV-Vis spectroscopy, High Performance Liquid Chromatography (HPLC) and Chemical Oxygen Demand (COD). Thus, photocatalytic activity to remove 4-CP from water employing GO and GEO without doping is successfully showed, and therefore, a new gate in research for these materials is opened.

15.
EMBO J ; 33(17): 1912-27, 2014 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-25024434

RESUMEN

Neuronal histone acetylation has been linked to memory consolidation, and targeting histone acetylation has emerged as a promising therapeutic strategy for neuropsychiatric diseases. However, the role of histone-modifying enzymes in the adult brain is still far from being understood. Here we use RNA sequencing to screen the levels of all known histone acetyltransferases (HATs) in the hippocampal CA1 region and find that K-acetyltransferase 2a (Kat2a)--a HAT that has not been studied for its role in memory function so far--shows highest expression. Mice that lack Kat2a show impaired hippocampal synaptic plasticity and long-term memory consolidation. We furthermore show that Kat2a regulates a highly interconnected hippocampal gene expression network linked to neuroactive receptor signaling via a mechanism that involves nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). In conclusion, our data establish Kat2a as a novel and essential regulator of hippocampal memory consolidation.


Asunto(s)
Regulación de la Expresión Génica , Redes Reguladoras de Genes , Histona Acetiltransferasas/metabolismo , Memoria , Animales , Región CA1 Hipocampal/enzimología , Perfilación de la Expresión Génica , Histona Acetiltransferasas/genética , Ratones , Ratones Noqueados
16.
Materials (Basel) ; 6(3): 911-926, 2013 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-28809348

RESUMEN

Carbon nanostructures have played an important role in creating a new field of materials based on carbon. Chemical modification of carbon nanostructures through grafting has been a successful step to improve dispersion and compatibility in solvents, with biomolecules and polymers to form nanocomposites. In this sense carbohydrates such as chitosan are extremely valuable because their functional groups play an important role in diversifying the applications of carbon nanomaterials. This paper reports the covalent attachment of chitosan onto graphene oxide, taking advantage of this carbohydrate at the nanometric level. Grafting is an innovative route to modify properties of graphene, a two-dimensional nanometric arrangement, which is one of the most novel and promising nanostructures. Chitosan grafting was achieved by redox reaction using different temperature conditions that impact on the morphology and features of graphene oxide sheets. Transmission Electron Microscopy, Fourier Transform Infrared, Raman and Energy Dispersive spectroscopies were used to study the surface of chitosan-grafted-graphene oxide. Results show a successful modification indicated by the functional groups found in the grafted material. Dispersions of chitosan-grafted-graphene oxide samples in water and hexane revealed different behavior due to the chemical groups attached to the graphene oxide sheet.

17.
Materials (Basel) ; 6(8): 3494-3513, 2013 Aug 14.
Artículo en Inglés | MEDLINE | ID: mdl-28811448

RESUMEN

Electrospun one dimensional (1D) and two dimensional (2D) carbon based polymer nanocomposites are studied in order to determine the effect provided by the two differently structured nanofillers on crystallinity and thermo-mechanical properties of the nanofibres. The nanomaterials studied are pristine carbon nanotubes, oxidised carbon nanotubes, reduced graphene oxide and graphene oxide. Functional groups associated with the order structure of the polymers are analysed by infrared and Raman spectroscopies; the morphology is studied by scanning electron microscopy and the crystallinity properties are investigated by differential scanning calorimetry and X-ray diffraction. Differences in crystallisation behaviour between 1D and 2D carbon based nanofibres are shown by their crystallinity degree and their crystal sizes. The nanocomposite crystal sizes perpendicular to the plane (100) decrease with nanofiller content in all cases. The crystallinity trend and crystal sizes are in accordance with storage modulus response. The results also suggest that functionalisation favours interfacial bonding and dispersion of the nanomaterials within the polymer matrix. As a consequence the number of nucleating sites increases which in turn decreases the crystal size in the nanocomposites. These features explain the improved thermo-mechanical properties in the nanocomposites.

18.
Mutat Res ; 731(1-2): 68-74, 2012 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-22119781

RESUMEN

Malnutrition is a serious public health problem that affects approximately one third of all children. Developing countries have the highest incidence of malnourished children, and approximately 60% of deaths that occur in children under five are directly related to malnutrition and associated diseases. The relationship between malnutrition and genetic damage has been widely studied in humans and animal models. The micronucleus (MN) assay is useful in detecting chromosome damage induced by several factors. The aim of this study was to evaluate the effects of infection and malnutrition on the frequency of MN in erythrocytes from the peripheral blood of well-nourished, uninfected (WN) and well-nourished, infected (WNI) children, and moderately malnourished (UNM) and severely malnourished (UNS) children, both with infection, using a flow cytometric analysis technique. The percentage of reticulocytes (RETs) was significantly higher (1.5-fold) in WNI children than well-nourished controls. In addition, the UNS group had a 2.2-fold increase in the percentage of RETs compared to the WNI group. The frequency of micronucleated reticulocytes (MN-RETs) was 2.5 times greater, in WNI group compared to the WN group. These frequencies were significantly higher (1.7- and 2.1-fold) in UNM and UNS, respectively, compared to the WNI group. The results suggest that infection and malnutrition induce DNA damage in children.


Asunto(s)
Infecciones Bacterianas/genética , Daño del ADN , Desnutrición/genética , Micronúcleos con Defecto Cromosómico , Reticulocitos , Infecciones Bacterianas/sangre , Recuento de Células Sanguíneas , Niño , Trastornos de la Nutrición del Niño/genética , Preescolar , Femenino , Citometría de Flujo , Humanos , Lactante , Masculino , Desnutrición/sangre
19.
Int J Mol Sci ; 12(3): 1908-20, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21673930

RESUMEN

Chitosan is an amino polysaccharide found in nature, which is biodegradable, nontoxic and biocompatible. It has versatile features and can be used in a variety of applications including films, packaging, and also in medical surgery. Recently a possibility to diversify chitosan properties has emerged by combining it with synthetic materials to produce novel natural-synthetic hybrid polymers. We have studied structural and thermophysical properties of chitosan + starch + poly(ethylene terephthalate) (Ch + S + PET) fibers developed via electrospinning. Properties of these hybrids polymers are compared with extant chitosan containing hybrids synthesized by electrospinning. Molecular interactions and orientation in the fibers are analyzed by infrared and Raman spectroscopies respectively, morphology by scanning electron microscopy and thermophysical properties by thermogravimetric analysis and differential scanning calorimetry. Addition of PET to Ch + S systems results in improved thermal stability at elevated temperatures.


Asunto(s)
Materiales Biocompatibles/química , Quitosano/química , Polietilenglicoles/química , Polímeros/química , Almidón/química , Materiales Biocompatibles/síntesis química , Rastreo Diferencial de Calorimetría , Microscopía Electrónica de Rastreo , Tereftalatos Polietilenos , Polímeros/síntesis química , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Temperatura , Termogravimetría
20.
Proc Natl Acad Sci U S A ; 107(13): 6058-63, 2010 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-20231476

RESUMEN

Locus ceruleus (LC)-supplied norepinephrine (NE) suppresses neuroinflammation in the brain. To elucidate the effect of LC degeneration and subsequent NE deficiency on Alzheimer's disease pathology, we evaluated NE effects on microglial key functions. NE stimulation of mouse microglia suppressed Abeta-induced cytokine and chemokine production and increased microglial migration and phagocytosis of Abeta. Induced degeneration of the locus ceruleus increased expression of inflammatory mediators in APP-transgenic mice and resulted in elevated Abeta deposition. In vivo laser microscopy confirmed a reduced recruitment of microglia to Abeta plaque sites and impaired microglial Abeta phagocytosis in NE-depleted APP-transgenic mice. Supplying the mice the norepinephrine precursor L-threo-DOPS restored microglial functions in NE-depleted mice. This indicates that decrease of NE in locus ceruleus projection areas facilitates the inflammatory reaction of microglial cells in AD and impairs microglial migration and phagocytosis, thereby contributing to reduced Abeta clearance. Consequently, therapies targeting microglial phagocytosis should be tested under NE depletion.


Asunto(s)
Enfermedad de Alzheimer/metabolismo , Enfermedad de Alzheimer/patología , Locus Coeruleus/metabolismo , Locus Coeruleus/patología , Microglía/metabolismo , Norepinefrina/metabolismo , Enfermedad de Alzheimer/genética , Péptidos beta-Amiloides/metabolismo , Precursor de Proteína beta-Amiloide/genética , Precursor de Proteína beta-Amiloide/metabolismo , Animales , Encéfalo/metabolismo , Encéfalo/patología , Línea Celular , Movimiento Celular/efectos de los fármacos , Movimiento Celular/fisiología , Quimiocinas/biosíntesis , Citocinas/biosíntesis , Modelos Animales de Enfermedad , Femenino , Humanos , Técnicas In Vitro , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Ratones , Ratones Transgénicos , Microglía/efectos de los fármacos , Microglía/patología , Norepinefrina/deficiencia , Norepinefrina/farmacología , Fagocitosis/efectos de los fármacos , Fagocitosis/fisiología , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Transcripción Genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...