Flexible metallic core-shell nanostructured electrodes for neural interfacing.

Electrodes with nanostructured surface have emerged as promising low-impedance neural interfaces that can avoid the charge-injection restrictions typically associated to microelectrodes. In this work, we propose a novel approximation, based on a two-step template assisted electrodeposition technique, to obtain flexible nanostructured electrodes coated with core-shell Ni-Au vertical nanowires. These nanowires benefit from biocompatibility of the Au shell exposed to the environment and the mechanical properties of Ni that allow for nanowires longer and more homogeneous in length than their only-Au counterparts. The nanostructured electrodes show impedance values, measured by electrochemical impedance spectroscopy (EIS), at least 9 times lower than those of flat reference electrodes. This ratio is in good accordance with the increased effective surface area determined both from SEM images and cyclic voltammetry measurements, evidencing that only Au is exposed to the medium. The observed EIS profile evolution of Ni-Au electrodes over 7 days were very close to those of Au electrodes and differently from Ni ones. Finally, the morphology, viability and neuronal differentiation of rat embryonic cortical cells cultured on Ni-Au NW electrodes were found to be similar to those on control (glass) substrates and Au NW electrodes, accompanied by a lower glial cell differentiation. This positive in-vitro neural cell behavior encourages further investigation to explore the tissue responses that the implantation of these nanostructured electrodes might elicit in healthy (damaged) neural tissues in vivo, with special emphasis on eventual tissue encapsulation.

A Platform for Addressing Individual Magnetite Islands Grown Epitaxially on Ru(0001) and Manipulating Their Magnetic Domains.

We have grown high-quality magnetite micrometric islands on ruthenium stripes on sapphire through a combination of magnetron sputtering (Ru film), high-temperature molecular beam epitaxy (oxide islands), and optical lithography. The samples have been characterized by atomic force microscopy, Raman spectroscopy, X-ray absorption and magnetic circular dichroism in a photoemission microscope. The magnetic domains on the magnetite islands can be modified by the application of current pulses through the Ru stripes in combination with magnetic fields. The modification of the magnetic domains is explained by the Oersted field generated by the electrical current flowing through the stripes underneath the magnetite nanostructures. The fabrication method is applicable to a wide variety of rock salt and spinel oxides.

Electrodeposition as a Tool for Nanostructuring Magnetic Materials.

Electrodeposition has appeared in the last year as a non-expensive and versatile technique for the growth of nanomaterials. We review the main characteristics of electrodeposition that make this technique very suitable for its combination with different nanofabrication tools and the possibilities that this combination offers to fabricate nanowires and more complex tridimensional nanostructures. Finally, we overview the present and future impact of electrodeposition on the fabrication of a novel generation of nanomaterials with potential impact in nanomagnetism and spintronics.

Electrodeposited Magnetic Nanowires with Radial Modulation of Composition.

In the last few years, magnetic nanowires have gained attention due to their potential implementation as building blocks in spintronics applications and, in particular, in domain-wall- based devices. In these devices, the control of the magnetic properties is a must. Cylindrical magnetic nanowires can be synthesized rather easily by electrodeposition and the control of their magnetic properties can be achieved by modulating the composition of the nanowire along the axial direction. In this work, we report the possibility of introducing changes in the composition along the radial direction, increasing the degrees of freedom to harness the magnetization. In particular, we report the synthesis, using template-assisted deposition, of FeNi (or Co) magnetic nanowires, coated with a Au/Co (Au/FeNi) bilayer. The diameter of the nanowire as well as the thickness of both layers can be tuned at will. In addition to a detailed structural characterization, we report a preliminary study on the magnetic properties, establishing the role of each layer in the global collective behavior of the system.

Scaling Up the Production of Electrodeposited Nanowires: A Roadmap towards Applications.

The use of metallic nanowires is mostly reduced to scientific areas where a small quantity of nanostructures are needed. In order to broaden the applicability of these nanomaterials, it is necessary to establish novel synthesis protocols that provide a larger amount of nanowires than the conventional laboratory fabrication processes at a more competitive cost. In this work, we propose several modifications to the conventional electrochemical synthesis of nanowires in order to increase the production with considerably reduced production time and cost. To that end, we use a soft anodization procedure of recycled aluminum at room temperature to produce the alumina templates, followed by galvanostatic growth of CoFe nanowires. We studied their morphology, composition and magnetic configuration, and found that their properties are very similar to those obtained by conventional methods.

Helical surface magnetization in nanowires: the role of chirality.

Nanomagnetism is nowadays expanding into three dimensions, triggered by the discovery of new magnetic phenomena and their potential use in applications. This shift towards 3D structures should be accompanied by strategies and methodologies to map the tridimensional spin textures associated. We present here a combination of dichroic X-ray transmission microscopy at different angles and micromagnetic simulations allowing to determine the magnetic configuration of cylindrical nanowires. We have applied it to permalloy nanowires with equispaced chemical barriers that can act as pinning sites for domain walls. The magnetization at the core is longitudinal and generates at the surface of the wire helical magnetization. Different types of domain walls are found at the pinning sites, which respond differently to applied fields depending on the relative chirality of the adjacent domains.

Disfunción crónica de órganos en pacientes con drepanocitosis. Parte II: manifestaciones renales, neurológicas y sensoriales / Chronic organ dysfunction in patients with sickle cell disease. Part II: renal, neurological and sensory manifestations

Introducción: El aumento de la expectativa de vida de pacientes con drepanocitosis, provoca que se sumen comorbilidades y disfunción crónica de órganos a las manifestaciones clínicas de la enfermedad. Objetivos: Analizar las alteraciones renales, neurológicas y sensoriales que aparecen en pacientes con drepanocitosis como manifestaciones de la disfunción orgánica crónica. Métodos: Se realizó una revisión de artículos publicados en los últimos 10 años con el uso de los buscadores PubMed, SciELO y Google Académico. Los términos de búsqueda fueron: drepanocitosis, disfunción orgánica, mortalidad, proteinuria, enfermedad renal crónica, infarto cerebral silente, trastornos neurocognitivos, retinopatía, sordera neurosensorial. Análisis y síntesis de la información: El efecto combinado de afectación glomerular, tubular e intersticial acarrea una disminución paulatina de la función renal. La progresión a la enfermedad renal crónica terminal es común y se asocia a incremento de la mortalidad. Las complicaciones del sistema nervioso central también pueden tener un impacto negativo en la supervivencia o provocar secuelas que influyen en la calidad de vida de los enfermos. Las afectaciones sensoriales tienen repercusiones biopsicosociales. Se describen aspectos relacionados con la prevalencia, diagnóstico y tratamiento de estas complicaciones. Conclusiones: Un seguimiento de los pacientes basado en estrategias para prevenir y diagnosticar de forma precoz las manifestaciones de disfunción crónica de órganos, puede disminuir las consecuencias desfavorables de estas complicaciones(AU)

Introduction: The increase in life expectancy of patients with sickle cell disease causes co-morbidities and chronic organ dysfunction to be added to the clinical manifestations of the disease. Objectives: To analyze the renal, neurological and sensory alterations that appear in patients with sickle cell disease as manifestations of chronic organic dysfunction. Methods: A review of the articles published in the last ten years was carried out using the search engines PubMed, SciELO and Google Scholar. The search terms were: sickle cell disease, organ dysfunction, mortality, proteinuria, chronic kidney disease, silent cerebral infarction, neurocognitive disorders, retinopathy, sensorineural deafness Analysis and synthesis of information: The combined effect of glomerular, tubular and interstitial involvement leads to a gradual decline in kidney function. Progression to end-stage chronic kidney disease is common and is associated with increased mortality. Central nervous system complications can also have a negative impact on survival or cause sequelae that influence the quality of life of patients. Sensory impairments have biopsychosocial repercussions. Aspects related to the prevalence, diagnosis and treatment of these complications are described. Conclusions: A follow-up of patients based on strategies to prevent and diagnose early the manifestations of chronic organ dysfunction can reduce the unfavorable consequences of these complications(AU)

Disfunción crónica de órganos en pacientes con drepanocitosis. Parte I: manifestaciones cardiorrespiratorias / Chronic organ dysfunction in patients with sickle cell anemia. Part I: cardiorespiratory manifestations

Introducción: En la actualidad la mayoría de los pacientes con anemia falciforme alcanzan la adultez. La disfunción crónica de órganos constituye la causa primaria de muerte y representa un desafío en el manejo de estos enfermos. Objetivo: Analizar los aspectos generales de la disfunción orgánica crónica en pacientes con drepanocitosis y profundizar en las alteraciones cardiorrespiratorias. Métodos: Se realizó una revisión de los artículos publicados en los últimos diez años con el uso de los buscadores PubMed, SciELO y Google Académico. Los términos de búsqueda fueron: anemia de células falciformes, disfunción orgánica, mortalidad, hipertensión pulmonar, enfermedad pulmonar crónica, asma, apnea obstructiva del sueño. Análisis y síntesis de la información: Con el aumento de la expectativa de vida, en el manejo de los pacientes con drepanocitosis, gana en relevancia el diagnóstico precoz y el tratamiento oportuno de la disfunción crónica de órganos. Este es un proceso que comienza en la infancia, pero se hace más evidente en la etapa adulta. Las manifestaciones cardiorrespiratorias más comunes y con impacto en la morbilidad y en la mortalidad son: la hipertensión pulmonar y la enfermedad pulmonar crónica. Se describen aspectos relacionado con la prevalencia, diagnóstico, implicaciones en la evolución de los enfermos y aspectos relacionados con su tratamiento. Conclusiones: La hipertensión pulmonar y la enfermedad pulmonar crónica son frecuentes en pacientes con drepanocitosis. Ambas complicaciones tienen un impacto negativo en la evolución de estos enfermos y se asocian a aumento de la mortalidad. La detección temprana de estas afecciones, permite tomar acciones terapéuticas para disminuir sus consecuencias(AU)

Introduction: Currently, most patients with sickle cell disease reach adulthood. Chronic organ dysfunction constitutes the primary cause of death and represents a challenge in the management of these patients. Objectives: To analyze the general aspects of chronic organic dysfunction in patients with sickle cell disease and to delve into the cardiorespiratory ones. Methods: A review of the articles published in the last ten years was carried out using the PubMed, SciELO and Google Scholar search engines. The search terms were: sickle cell anemia, organ dysfunction, mortality, pulmonary hypertension, chronic lung disease, asthma, obstructive sleep apnea. Information analysis and synthesis: With the increase in life expectancy, in the management of patients with sickle cell disease, early diagnosis and timely treatment of chronic organ dysfunction gain relevance. This is a process that begins in childhood, but becomes more apparent in adulthood. The most common cardiorespiratory manifestations with an impact on morbidity and mortality are: pulmonary hypertension and chronic lung disease. Aspects related to prevalence, diagnosis, implications in the evolution of patients and aspects related to their treatment are described. Conclusions: Pulmonary hypertension and chronic lung disease are frequent in patients with sickle cell disease. Both complications have a negative impact on the evolution of these patients and are associated with increased mortality. Early detection of these conditions allows therapeutic actions to be taken to reduce their consequences(AU)

Estimación del filtrado glomerular por valores séricos de creatinina y cistatina C en adultos con drepanocitosis / Estimation of glomerular filtration rate using serum creatinine and cystatin C in adults with sickle cell anemia

Introducción: La estimación del filtrado glomerular a partir de la concentración sérica de creatinina en pacientes con drepanocitosis, es anormal cuando hay un deterioro extenso de la función renal. Objetivos: Evaluar la estimación del filtrado glomerular con el uso de creatinina, de cistatina C y de ambas determinaciones, en adultos con drepanocitosis. Métodos: Estudio observacional, descriptivo de corte transversal. Se incluyeron 44 adultos con drepanocitosis en quienes se estimó el filtrado glomerular, con el uso de creatinina, de cistatina C y de ambas, según las fórmulas de CDK-EPI. Resultados: Se encontraron discrepancias en el filtrado glomerular estimado por creatinina, por cistatina C y por ambas (medias: 112,2 ± 28,4; 55,7 ± 23,1 y 75,1 ± 24,7 mL/min/ 1,73 m2; respectivamente). Los porcentajes más elevados de pacientes con hiperfiltración por creatinina corresponden al genotipo SS y todos los que tiene enfermedad renal crónica en estadio 4 (filtrado estimado por cistatina C y mediante la combinación de ambos marcadores), tienen este tipo de hemoglobinopatía. La hiperfiltración fue más común en los más jóvenes y la disminución del filtrado en los mayores de 40 años. Conclusiones: La estimación del filtrado glomerular muestra diferencias entre los tres métodos estudiados. Con el uso de creatinina está sobrestimado y una elevada proporción de pacientes son clasificados como con hiperfiltración. El uso de la cistatina C o la combinación de ambas determinaciones, pudieran ofrecer una estimación más exacta del filtrado glomerular en pacientes con drepanocitosis(AU)

Introduction: The estimation of the glomerular filtration rate from the serum concentration of creatinine in patients with sickle cell disease is abnormal when there is an extensive deterioration of renal function. Objective: To estimate the glomerular filtration rate with the use of creatinine, cystatin C and both determinations, in adults with sickle cell disease. Determine if there are differences between these methods. Methods: Observational, descriptive cross-sectional study. Forty-four adults with sickle cell disease were included in whom the glomerular filtration rate was estimated using creatinine, cystatin C and both, according to the CDK-EPI formulas. Results: Discrepancies were found in the glomerular filtration rate estimated by creatinine, by cystatin C and by both (means: 112.2 ± 28.4; 55.7 ± 23.1 and 75.1 ± 24.7 mL/min/1.73 m2; respectively). The highest percentages of patients with creatinine hyperfiltration correspond to the SS genotype and all those with stage 4 chronic kidney disease (estimated filtration by cystatin C and by the combination of both markers), have this type of hemoglobinopathy. Hyperfiltration was more common in the youngest and decreased filtration in those older than 40 years. Conclusions: The estimation of the glomerular filtration rate shows differences between the three methods studied. With the use of creatinine, it is overestimated and a high proportion of patients are classified as having hyperfiltration. The use of cystatin C or the combination of both determinations could offer a more accurate estimate of glomerular filtration rate in patients with sickle cell disease(AU)

Evolución clínico-epidemiológica de pacientes con diagnóstico de dengue. Enero-junio 2017 / Clinical-epidemiological evolution of patients diagnosed with dengue. January-June 2017

RESUMEN Fundamento: El estudio del dengue como entidad clínica y epidemiológica cobra cada día mayor importancia dada la creciente tendencia al incremento del número casos y de la tasa de complicaciones reportadas que presentan los pacientes. Objetivo: caracterizar la evolución clínico-epidemiológica de pacientes con diagnóstico de dengue. Métodos: se realizó un estudio descriptivo retrospectivo de serie de casos en el Hospital General de Cienfuegos, en el período enero-junio de 2017. Se incluyeron todos los pacientes con diagnóstico confirmado de dengue por IgM (N=83). Resultados: la media de la edad fue de 42 años. El grupo etario más representado fue el de 40-49 años (28,9 %). Predominaron los pacientes con color blanco de la piel (74,7 %), y del sexo femenino (59,0 %). El municipio con más casos fue Cienfuegos. La fiebre fue el principal motivo de consulta (96,4 %), seguido por la cefalea (78,3 %) y el dolor retroocular (64,4 %). El 36,1 % de los casos presento algún signo de alarma. El hallazgo paraclínico más frecuente fue el predominio linfocitario (95,2 %). No se reportaron alteraciones ultrasonográficas. Conclusión: la totalidad de los pacientes estudiados presentó una evolución favorable, menos de la mitad de ellos presentó algún signo de alarma, y ninguno desarrolló alguna de las llamadas formas graves de la enfermedad.

ABSTRACT Foundation: The study of dengue as a clinical and epidemiological entity is becoming increasingly important given the tendency to increase the number of cases and the rate of reported complications presented by patients suffering from it. Objective: to characterize the clinical-epidemiological evolution of patients diagnosed with dengue. Methods: a retrospective descriptive study of a series of cases was carried out at the General Hospital of Cienfuegos, in the period January-June 2017. All patients with a confirmed diagnosis of dengue by IgM (N = 83) were included. Results: the average age was 42 years. The most represented age group was 40-49 years (28.9%). Patients with white skin color (74.7%), and female sex (59.0%) predominated. The municipality with the most cases was Cienfuegos. Fever was the main reason for consultation (96.4%), followed by headache (78.3%) and retroocular pain (64.4%). 36.1% of the cases presented an alarm sign. The most frequent paraclinical finding was lymphocyte predominance (95.2%). No ultrasonographic abnormalities were reported.Conclusion: all the patients studied presented a favorable evolution. Less than half of them presented some warning sign, and none developed any of the so-called serious forms of the disease.

Enfermedad de Still del adulto. Presentación de un caso / Still´s disease in adults. Case presentation

La enfermedad de Still del adulto es una entidad de posible origen autoinmune, de etología desconocida y presentación infrecuente. Se caracteriza por fiebre alta, artritis, leucocitosis neutrofílica y exantema evanescente. Los valores de ferritina sérica por encima de 3 000 ng/mL son de gran valor para establecer el diagnóstico. En el presente artículo se describe el caso de un paciente de 28 años de edad, masculino, con un síndrome febril crónico, erupción cutánea, odinofagia y artritis. Se realizaron exámenes complementarios mediante los que se demostró la existencia de leucocitosis, elevación de los niveles de enzimas hepáticas y de ferritina sérica. La baja incidencia de la enfermedad, su complicada forma de presentación, así como la inexistencia de algún complementario confirmatorio para su diagnóstico, motivó a los autores a describir un paciente con enfermedad de Still del adulto. 

Still´s disease in adults is an entity with a possible autoimmune origin, of unknown etiology and infrequent presentation. It is characterized by high fever, netrophylic leukocytosis, and transient exanthema. The values of seric ferritin over 3 000 ng/mL are of great value to determine the diagnosis. It is described the case of a 28 year old male patient with chronic febrile syndrome, cutaneous rash, odynophagia and arthritis. Laboratory tests were performed which showed leukocytosis, high level of hepatic enzymes and seric ferritin. The low incidence of this disease, its complicated form of presentation, so as the non- existence of any confirming test for its diagnosis, motivated the authors to describe a patient with Still´s disease of the adult.