Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 49
Filtrar
1.
Rev. colomb. cardiol ; 28(5): 473-477, sep.-oct. 2021. graf
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1357215

RESUMO

Resumen Se presenta el caso de un hombre de 31 años, con historia de fibrilación auricular paroxística, a quien se realizó exitosamente una ablación por radiofrecuencia de venas pulmonares guiada por un sistema de mapeo tridimensional EnSite™. Tres meses después del procedimiento presentó hemoptisis y dolor torácico de características pleuríticas, motivo por el cual se le realizó una angiotomografía computarizada coronaria que evidenció una estenosis grave de la vena pulmonar superior izquierda y una estenosis moderada de la vena inferior izquierda. El paciente fue sometido a angioplastia con balón, con la cual se normalizó la perfusión pulmonar.


Abstract We report the case of a 31-year-old male patient with a history of paroxysmal atrial fibrillation, who underwent a successful radiofrequency pulmonary vein ablation using EnSite™ three-dimensional mapping system. Three months after the procedure, patient presented with hemoptysis and pleuritic chest pain. A coronary computed tomography angiography was performed, which showed a severe left superior pulmonary vein stenosis and a moderate left inferior pulmonary vein stenosis. A balloon angioplasty was performed with subsequent restoration of pulmonary perfusion.


Assuntos
Humanos , Veias Pulmonares , Angioplastia , Fibrilação Atrial , Ablação por Cateter
2.
Nano Lett ; 21(15): 6432-6440, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34283622

RESUMO

Artificial intelligence and machine learning are growing computing paradigms, but current algorithms incur undesirable energy costs on conventional hardware platforms, thus motivating the exploration of more efficient neuromorphic architectures. Toward this end, we introduce here a memtransistor with gate-tunable dynamic learning behavior. By fabricating memtransistors from monolayer MoS2 grown on sapphire, the relative importance of the vertical field effect from the gate is enhanced, thereby heightening reconfigurability of the device response. Inspired by biological systems, gate pulses are used to modulate potentiation and depression, resulting in diverse learning curves and simplified spike-timing-dependent plasticity that facilitate unsupervised learning in simulated spiking neural networks. This capability also enables continuous learning, which is a previously underexplored cognitive concept in neuromorphic computing. Overall, this work demonstrates that the reconfigurability of memtransistors provides unique hardware accelerator opportunities for energy efficient artificial intelligence and machine learning.


Assuntos
Inteligência Artificial , Molibdênio , Algoritmos , Computadores , Redes Neurais de Computação
3.
Adv Mater ; 33(34): e2100994, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34270835

RESUMO

The growing demand for ubiquitous data collection has driven the development of sensing technologies with local data processing. As a result, solution-processed semiconductors are widely employed due to their compatibility with low-cost additive manufacturing on a wide range of substrates. However, to fully realize their potential in sensing applications, high-performance scalable analog amplifiers must be realized. Here, ohmic-contact-gated transistors (OCGTs) based on solution-processed semiconducting single-walled carbon nanotubes are introduced to address this unmet need. This new device concept enables output current saturation in the short-channel limit without compromising output current drive. The resulting OCGTs are used in common-source amplifiers to achieve the highest width-normalized output current (≈30 µA µm-1 ) and length-scaled signal gain (≈230 µm-1 ) to date for solution-processed semiconductors. The utility of these amplifiers for emerging sensing technologies is demonstrated by the amplification of complex millivolt-scale analog biological signals including the outputs of electromyography, photoplethysmogram, and accelerometer sensors. Since the OCGT design is compatible with other solution-processed semiconducting materials, this work establishes a general route to high-performance, solution-processed analog electronics.

4.
Repert. med. cir ; 30(1): 13-21, 2021. Ilus., tab.
Artigo em Inglês | COLNAL, LILACS | ID: biblio-1281415

RESUMO

El gen AIP (proteína moduladora de la actividad del receptor de aril hidrocarburos) se localiza en la región 11q13.2 y codifica para una proteína de 330 aminoácidos que interactúa con el factor de transcripción AhR (receptor para aril hidrocarburos). Las mutaciones en este gen se han asociado con adenomas pituitarios aislados de tipo familiar (APAF). Se caracterizan por una presentación temprana (alrededor de 20 años), por lo regular producen hormona de crecimiento y/o prolactina, tienen un comportamiento clínico agresivo y poca respuesta a análogos de somatostatina.


The AIP gene (aryl hydrocarbon receptor interacting protein) is located on chromosome 11q13.2 and encodes a 330 amino acid protein which interacts with the aryl hydrocarbon receptor (AHR) transcription factor. Mutations in the AIP gene have been associated with familial isolated pituitary adenomas (FIPA). They characterize by an early-onset (around the age of 20 years old) and for being aggressive, growth hormone and/or prolactin-secreting tumors, with poor response to somatostatin analogues.


Assuntos
Neoplasias Hipofisárias/genética , Peptídeos e Proteínas de Sinalização Intercelular , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Doenças da Hipófise/genética , Doenças da Hipófise/metabolismo , Neoplasias Hipofisárias/metabolismo , Adenoma/genética , Adenoma/metabolismo
5.
Rev Peru Med Exp Salud Publica ; 37(1): 148-154, 2020.
Artigo em Espanhol | MEDLINE | ID: mdl-32520178

RESUMO

The involvement in the use of alcohol represents a significant risk for the mental and physical development of adolescents. The objective of this article is to describe the evolution of alcohol consumption in male and female secondary school students in Peru during the 2007-2017 period, emphasizing the findings on the reduction of differences in the usage magnitudes between both genders and recent information on high prevalence in the adolescent female population. Recommendations are proposed aimed at expanding coverage and quality of preventive programs in the school, adaptation of gender-sensitive content and pre ventive strategies, creation of articulated mechanisms for early detection, referral and brief intervention, development of specific guidelines and protocols for treatment for adolescents, and strengthening of the intersectoral articulation for the reduction of alcohol consumption in adolescents.


El involucramiento en el uso de alcohol representa un riesgo significativo para el desarrollo mental y físico de los adolescentes. El objetivo de este artículo es describir la evolución del consumo de alcohol en escolares hombres y mujeres de nivel secundario del Perú durante el periodo 2007-2017, haciendo énfa sis en los hallazgos sobre la reducción de las diferencias en las magnitudes de uso entre ambos géneros y la información reciente sobre mayor prevalencia en la población femenina adolescente. Se proponen recomendaciones dirigidas a la ampliación de cobertura y calidad de los programas preventivos en el ámbito escolar, adaptación de contenidos y estrategias preventivas sensibles al género, conformación de mecanismos articulados de detección temprana, derivación e intervención breve, elaboración de guías y protocolos específicos de tratamiento para adolescentes, y fortalecimiento de la articulación intersecto rial para la reducción del consumo del alcohol en menores de edad.


Assuntos
Consumo de Bebidas Alcoólicas , Estudantes , Adolescente , Consumo de Bebidas Alcoólicas/epidemiologia , Feminino , Humanos , Masculino , Peru/epidemiologia , Prevalência , Instituições Acadêmicas , Distribuição por Sexo , Estudantes/psicologia , Estudantes/estatística & dados numéricos
6.
Preprint em Espanhol | SciELO Preprints | ID: pps-868

RESUMO

Human behavior has a decisive influence on the transmission of COVID-19 and must play a main role in national public health efforts. This article analyzes variables of psychosocial intervention that have shown a relationship with the performance of protective behaviors in pandemic contexts. These variables has been organized according to the following intervention objectives: increasing risk perception and self-efficacy, reducing invulnerability bias, managing anxiety and uncertainty, promoting healthy social norms, promoting social capital, promoting behaviors prosocial, and build trust in the authorities and science. Finally, a framework is proposed for the design and implementation of behavioral public health interventions to reduce the spread of COVID-19 in Peru.


La conducta humana influye de manera decisiva en la transmisión del COVID-19 y debe tener un rol protagónico en los esfuerzos nacionales de salud pública. Este artículo analiza variables de intervención psicosocial que han mostrado relación con la realización de conductas de protección en contextos de pandemia. Estas variables se han organizado en función de los siguientes objetivos de intervención: incrementar la percepción de riesgo y la autoeficacia, reducir el sesgo de invulnerabilidad, gestionar la ansiedad y la incertidumbre, promover normas sociales promotoras de salud, promover el capital social, promover conductas prosociales, y generar confianza en las autoridades y la ciencia. Finalmente, se propone un marco de referencia para el diseño e implementación de intervenciones conductuales de salud pública para reducir la propagación del COVID-19 en el Perú.

7.
Adv Mater ; 32(41): e1905654, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32255238

RESUMO

For the past half century, silicon has served as the primary material platform for integrated circuit technology. However, the recent proliferation of nontraditional electronics, such as wearables, embedded systems, and low-power portable devices, has led to increasingly complex mechanical and electrical performance requirements. Among emerging electronic materials, single-walled carbon nanotubes (SWCNTs) are promising candidates for next-generation computing as a result of their superlative electrical, optical, and mechanical properties. Moreover, their chirality-dependent properties enable a wide range of emerging electronic applications including sub-10 nm complementary field-effect transistors, optoelectronic integrated circuits, and enantiomer-recognition sensors. Here, recent progress in SWCNT-based computing devices is reviewed, with an emphasis on the relationship between chirality enrichment and electronic functionality. In particular, after highlighting chirality-dependent SWCNT properties and chirality enrichment methods, the range of computing applications that have been demonstrated using chirality-enriched SWCNTs are summarized. By identifying remaining challenges and opportunities, this work provides a roadmap for next-generation SWCNT-based computing.

8.
Nat Commun ; 11(1): 1565, 2020 03 26.
Artigo em Inglês | MEDLINE | ID: mdl-32218433

RESUMO

Spiking neural networks exploit spatiotemporal processing, spiking sparsity, and high interneuron bandwidth to maximize the energy efficiency of neuromorphic computing. While conventional silicon-based technology can be used in this context, the resulting neuron-synapse circuits require multiple transistors and complicated layouts that limit integration density. Here, we demonstrate unprecedented electrostatic control of dual-gated Gaussian heterojunction transistors for simplified spiking neuron implementation. These devices employ wafer-scale mixed-dimensional van der Waals heterojunctions consisting of chemical vapor deposited monolayer molybdenum disulfide and solution-processed semiconducting single-walled carbon nanotubes to emulate the spike-generating ion channels in biological neurons. Circuits based on these dual-gated Gaussian devices enable a variety of biological spiking responses including phasic spiking, delayed spiking, and tonic bursting. In addition to neuromorphic computing, the tunable Gaussian response has significant implications for a range of other applications including telecommunications, computer vision, and natural language processing.

9.
Rev. peru. med. exp. salud publica ; 37(1): 148-154, ene.-mar. 2020. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1101797

RESUMO

RESUMEN El involucramiento en el uso de alcohol representa un riesgo significativo para el desarrollo mental y físico de los adolescentes. El objetivo de este artículo es describir la evolución del consumo de alcohol en escolares hombres y mujeres de nivel secundario del Perú durante el periodo 2007-2017, haciendo énfa sis en los hallazgos sobre la reducción de las diferencias en las magnitudes de uso entre ambos géneros y la información reciente sobre mayor prevalencia en la población femenina adolescente. Se proponen recomendaciones dirigidas a la ampliación de cobertura y calidad de los programas preventivos en el ámbito escolar, adaptación de contenidos y estrategias preventivas sensibles al género, conformación de mecanismos articulados de detección temprana, derivación e intervención breve, elaboración de guías y protocolos específicos de tratamiento para adolescentes, y fortalecimiento de la articulación intersecto rial para la reducción del consumo del alcohol en menores de edad.


ABSTRACT The involvement in the use of alcohol represents a significant risk for the mental and physical development of adolescents. The objective of this article is to describe the evolution of alcohol consumption in male and female secondary school students in Peru during the 2007-2017 period, emphasizing the findings on the reduction of differences in the usage magnitudes between both genders and recent information on high prevalence in the adolescent female population. Recommendations are proposed aimed at expanding coverage and quality of preventive programs in the school, adaptation of gender-sensitive content and pre ventive strategies, creation of articulated mechanisms for early detection, referral and brief intervention, development of specific guidelines and protocols for treatment for adolescents, and strengthening of the intersectoral articulation for the reduction of alcohol consumption in adolescents.


Assuntos
Adolescente , Feminino , Humanos , Masculino , Estudantes , Consumo de Bebidas Alcoólicas , Peru/epidemiologia , Instituições Acadêmicas , Estudantes/psicologia , Estudantes/estatística & dados numéricos , Consumo de Bebidas Alcoólicas/epidemiologia , Prevalência , Distribuição por Sexo
10.
Repert. med. cir ; 29(2): 127-130, 2020. ilus., tab.
Artigo em Inglês, Espanhol | COLNAL, LILACS | ID: biblio-1147880

RESUMO

Es una lesión quística que surge del remanente epitelial de la bolsa de Rathke, casi siempre su diagnóstico es un hallazgo incidental ya que en la mayoría de los casos es asintomático. Cuando se manifiesta se debe a que ha aumentado lo suficiente su volumen hasta comprimir estructuras vecinas causando cefalea, alteraciones visuales y disfunción pituitaria. En su mayoría ocurre en adultos entre la cuarta y quinta década de vida. Presentamos el caso de una paciente femenina de 9 años de edad que consultó por talla baja al servicio de endocrinología, por lo cual se inició tratamiento con hormona de crecimiento y se solicitó una resonancia magnética nuclear (RMN) la cual reportó quiste de la bolsa de Rathke versus adenoma hipofisario.


Rathke pouch cysts are epithelium-lined cysts arising from the embryological remnants of Rathke ́s pouch. They are usually incidentally identified since the majority are asymptomatic. They become symptomatic when they enlarge enough to compress neighbor structures causing headache, visual disturbances and pituitary dysfunction. They occur mostly in adults in the fourth to fifth decades of life. A case is presented in a 9-year-old female patient who consulted for growth retardation to the endocrinology service. She was treated with growth hormone and a magnetic resonance imaging (MRI) scan reported Rathke ́s pouch cyst versus pituitary adenoma.


Assuntos
Humanos , Feminino , Criança , Doenças da Hipófise , Cefaleia , Quiasma Óptico , Cistos do Sistema Nervoso Central , Insuficiência de Crescimento
11.
Repert. med. cir ; 29(2): 127-130, 2020. Ilus., tab.
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-1222615

RESUMO

Es una lesión quística que surge del remanente epitelial de la bolsa de Rathke, casi siempre su diagnóstico es un hallazgo incidental ya que en la mayoría de los casos es asintomático. Cuando se manifiesta se debe a que ha aumentado lo suficiente su volumen hasta comprimir estructuras vecinas causando cefalea, alteraciones visuales y disfunción pituitaria. En su mayoría ocurre en adultos entre la cuarta y quinta década de vida. Presentamos el caso de una paciente femenina de 9 años de edad que consultó por talla baja al servicio de endocrinología, por lo cual se inició tratamiento con hormona de crecimiento y se solicitó una resonancia magnética nuclear (RMN) la cual reportó quiste de la bolsa de Rathke versus adenoma hipofisario.


Rathke pouch cysts are epithelium-lined cysts arising from the embryological remnants of Rathke ́s pouch. They are usually incidentally identified since the majority are asymptomatic. They become symptomatic when they enlarge enough to compress neighbor structures causing headache, visual disturbances and pituitary dysfunction. They occur mostly in adults in the fourth to fifth decades of life. A case is presented in a 9-year-old female patient who consulted for growth retardation to the endocrinology service. She was treated with growth hormone and a magnetic resonance imaging (MRI) scan reported Rathke ́s pouch cyst versus pituitary adenoma.


Assuntos
Feminino , Criança , Doenças da Hipófise , Cefaleia , Quiasma Óptico , Cistos do Sistema Nervoso Central , Insuficiência de Crescimento
12.
Repert. med. cir ; 29(2): 131-134, 2020.
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-1222626

RESUMO

Los autoanticuerpos son proteínas producidas en el organismo por la inducción de un antígeno propio del individuo el cual no reconocen y rechazan. Su aparición en sangre puede iniciarse tiempo antes de la presentación de síntomas o signos. El deterioro funcional de dos o más glándulas es una afectación endocrinológica múltiple que puede asociarse con otras patologías autoinmunes no endocrinas, tales como vitiligo, alopecia areata, gastritis autoinmune y anemia perniciosa. Se clasifica en tres síndromes poliendocrinos autoinmunes (SPA). En Europa la incidencia del tipo I es menor a 1:100000 por año y los 2 y 3 varían entre 1­2:100000 por año. Colombia no cuenta con registros que permitan calcularla. Se reporta el caso de un hombre de 18 años diagnosticado con hipotiroidismo autoinmune, a los 15 años de edad debutó con cetoacidosis diabética y a los 17 con posterior aparición de vitiligo. El manejo inicial se realizó con levotiroxina sódica y análogos de insulina. Este caso corresponde a un SPA tipo IIIA, ya que cursa con hipotiroidismo autoinmune, diabetes mellitus y como último hallazgo cronológico la asociación con vitiligo. La detección de una endocrinopatía autoinmune en pacientes jóvenes debe alertar sobre la posible existencia de un SPA


Autoantibodies are blood proteins produced in response to and counteracting a specific antigen. Autoantibodies may be present before signs and symptoms occur. A polyendocrinopathy is characterized by the coexistence of at least two endocrine glands insufficiency and may be associated with another non-endocrine autoimmune illness including vitiligo, alopecia areata, autoimmune gastritis and pernicious anemia. It is classified into three types of autoimmune polyglandular syndromes (APS). In Europe the incidence of APS-1 is less than one new case per 100000 persons per year and the incidence of the other two APS types vary between1 to 2 new cases per 100000 persons per year. APS incidence in Colombia cannot be estimated due to lack of records on this subject. We report the case of an 18-year-old male with autoimmune hypothyroidism diagnosed at 15 years of age, with onset of diabetic ketoacidosis at 17 followed by vitiligo. Therapy with levothyroxine 100 mcg daily and insulin glargine 10 units daily did not yield successful correction of APS in the patient. This patient was affected by APS- IIIA, characterized by the association of autoimmune hypothyroidism, diabetes mellitus and vitiligo, as the last manifestation. Detecting an autoimmune polyendocrinopathy in young patients should raise the suspicion of APS.


Assuntos
Humanos , Masculino , Adolescente , Doenças do Sistema Endócrino , Hipotireoidismo , Vitiligo , Poliendocrinopatias Autoimunes , Diabetes Mellitus Tipo 1
13.
Rev. Fac. Med. (Bogotá) ; 67(4): 623-628, Oct.-Dec. 2019. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1091988

RESUMO

Abstract Introduction: Papillary thyroid carcinoma is the most common endocrine neoplasm; therefore, markers with possible prognostic utility have been evaluated. Objective: To analyze the presence of RET/PTC1 rearrangement, lymphocytic thyroiditis and associated clinical features in patients with papillary thyroid cancer treated at the Hospital de San José in Bogotá, Colombia. Materials and methods: Clinical records of patients with complete thyroidectomy and diagnosis of papillary cancer were retrospectively identified. RNA was extracted from tumor tissue, and cDNA was obtained using inverse transcriptase to detect the rearrangement of the RET/PTC1 gene by means of qPCR. Results: 55 patients with papillary thyroid cancer were selected; 93% were females, and the mean age was 45.8 years. The most frequent histological variant was classic (49%). A relationship was found between lymphocytic thyroiditis and the number of positive nodes in segments other than central draining, as well as thyroiditis and antithyroid antibody value. No RET/PTC1 rearrangement expression was found. Conclusions: A relationship between lymphocytic thyroiditis and the number of positive nodes in segments other than central draining was found. Other molecular markers should be searched to differentiate the prognosis of these patients.


Resumen Introducción. El carcinoma papilar de tiroides es la neoplasia endocrina más común, por lo que se han evaluado marcadores con posible utilidad pronóstica. Objetivo. Analizar la presencia del rearreglo del RET/PTC1, tiroiditis linfocítica y características clínicas asociadas en pacientes con cáncer papilar de tiroides en el Hospital de San José de Bogotá D.C., Colombia. Materiales y métodos. Los casos con diagnóstico de cáncer papilar y tiroidectomía completa fueron seleccionados utilizando el registro de historias clínicas; el ARN se extrajo a partir del tejido tumoral y el ADNc se obtuvo utilizando una transcriptasa inversa para luego detectar el rearreglo del gen RET/PTC1 por medio de qPCR. Resultados. Se seleccionaron 55 pacientes con cáncer papilar de tiroides; 93% correspondió a género femenino, la edad promedio fue de 45.8 años y la variante histológica más frecuente fue la clásica (49%). Se evidenció una relación entre tiroiditis linfocítica y la cantidad de ganglios positivos en segmentos distintos al vaciamiento central, así como la tiroiditis y el valor de los anticuerpos antitiroideos. No se identificó la expresión del rearreglo RET/PTC1 en las muestras analizadas. Conclusiones. Se muestra una relación entre tiroiditis linfocítica y la cantidad de ganglios positivos en segmentos distintos al vaciamiento central. Se debe continuar la búsqueda de otros marcadores moleculares que permitan diferenciar el pronóstico en estos pacientes.

14.
Repert. med. cir ; 27(2): 109-113, 2018. ilus., tab.
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-981875

RESUMO

La anemia hemolítica autoinmune (AHAI) es un trastorno con autoanticuerpos dirigidos contra los glóbulos rojos lo que acorta su supervivencia. Su etiología es diversa, puede ser idiopática o secundaria a consumo de medicamentos o a enfermedades autoinmunes. La fisiopatología exacta sigue sin estar clara en los casos en que se ha descrito secundaria a enfermedad tiroidea, siendo la mayoría de los pacientes hipertiroideos en el momento del diagnóstico de AHAI. Presentamos un caso con antecedente de AHAI idiopática con múltiples exacerbaciones, que ingresa por síntomas sugestivos de tirotoxicosis vs tormenta tiroidea, manejado con metimazol, propanolol, corticoides y colestiramina. Se concluye que el paciente desarrolló una AHAI secundaria a un hipertiroidismo, por lo que es importante evaluar las causas secundarias y realizar un seguimiento estricto debido al componente autoinmune de su enfermedad


Autoimmune hemolytic anemia (AIHA) results from the formation of autoantibodies against red blood cells reducing their lifetime. Etiology of AIHA may be idiopathic, drug-induced or secondary to other autoimmune disorders. The pathophysiology of AIHA secondary to thyroid diseases remains unclear. Most patients have hyperthyroidism at the time of diagnosis of AIHA. We present a case of idiopathic AIHA with multiple exacerbations, who was admitted with symptoms suggestive of thyrotoxicosis or thyroid storm and was treated with methimazole, propranolol, corticoids and cholestyramine. We concluded the patient developed an AIHA secondary to hyperthyroidism, thus it is important to assess the secondary causes and conduct a close follow-up due to the autoimmune component of his disease


Assuntos
Humanos , Masculino , Adulto , Anemia Hemolítica Autoimune , Autoimunidade , Hipertireoidismo
15.
Repert. med. cir ; 27(3): 180-183, 2018.
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-982036

RESUMO

La hipoglicemia en pacientes no diabéticos se define como un nivel sérico menor de 55 mg/dL que puede ser parte de la tríada de Whipple (síntomas de hipoglicemia, niveles bajos de glucosa sérica y resolución de la sintomatología tras la normalización de la glicemia). Puede ser mediada o no por insulina, dando manifestaciones en ayunas (posabsorptiva) o posprandiales (reactiva). Con el aumento de la cirugía bariátrica se ha observado una mayor incidencia de complicaciones como la hipoglicemia posprandial por el síndrome de dumping. Presentación del caso: paciente con antecedente de cirugía bariátrica y evidencia posoperatoria de hipoglicemia posprandial. Las pruebas de ayuno y de alimentos mixtos confirmó el síndrome de dumping. Discusión y conclusiones: la hipoglicemia es una urgencia médica frecuente, en la mayoría de los casos secundaria al uso de medicamentos en pacientes con diabetes mellitus. No obstante, en los no diabéticos puede presentarse de forma espontánea y estar relacionada con múltiples condiciones clínicas. En el posoperatorio de cirugía bariátrica, la aparición del síndrome de dumping puede ser incapacitante, con manifestaciones tempranas o tardías. El diagnóstico se basa en la clínica y en estudios funcionales e imagenológicos que confirmen la presencia de hipoglicemia posprandial y un rápido vaciamiento gástrico. El tratamiento inicial se basa en cambios en la alimentación, aunque pueden ser necesarios fármacos e incluso procedimientos quirúrgicos cuando hay refractariedad. Es por esto que la elección de los pacientes llevados a cirugía bariátrica debe ser realizado por un grupo multidisciplinario.


Hypoglycemia in non-diabetics has been defined as a post-prandial glucose level of less than 55 mg/dl which may be part of Whipple ́s triad (symptoms of hypoglycemia, low plasma glucose and relief of symptoms with the correction of low glucose). It may be mediated by insulin or may not be mediated by insulin, with fasting (postabsorbative) or postprandial (reactive) manifestations. The incidence of complications, such as, postprandial hypoglycemia related to dumping syndrome, has increased with the use of bariatric surgery. A case is presented in a patient who underwent bariatric surgery experiencing postoperative postprandial hypoglycemia. Dumping syndrome was confirmed by fasting and mixed-meal tests. Discussion and Conclusions: hypoglycemia is a common medical emergency and is usually secondary to medications used to treat diabetes. However, it may be spontaneous in non-diabetics and may be associated with multiple clinical disorders. Postoperative dumping syndrome following bariatric surgery may be disabling, with early or late manifestations. Diagnosis is based on symptoms and functional and imaging studies which confirm postprandial hypoglycemia and a rapid gastric emptying. Initial treatment is based on dietary modification, although medical therapy or surgical intervention may be required in refractory cases. Thus, the selection of candidates to undergo bariatric surgery must be conducted by a multidisciplinary group.


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Cirurgia Bariátrica , Nesidioblastose , Síndrome de Esvaziamento Rápido , Hipoglicemia
16.
Nano Lett ; 17(8): 4976-4981, 2017 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-28671471

RESUMO

With the growing adoption of interconnected electronic devices in consumer and industrial applications, there is an increasing demand for robust security protocols when transmitting and receiving sensitive data. Toward this end, hardware true random number generators (TRNGs), commonly used to create encryption keys, offer significant advantages over software pseudorandom number generators. However, the vast network of devices and sensors envisioned for the "Internet of Things" will require small, low-cost, and mechanically flexible TRNGs with low computational complexity. These rigorous constraints position solution-processed semiconducting single-walled carbon nanotubes (SWCNTs) as leading candidates for next-generation security devices. Here, we demonstrate the first TRNG using static random access memory (SRAM) cells based on solution-processed SWCNTs that digitize thermal noise to generate random bits. This bit generation strategy can be readily implemented in hardware with minimal transistor and computational overhead, resulting in an output stream that passes standardized statistical tests for randomness. By using solution-processed semiconducting SWCNTs in a low-power, complementary architecture to achieve TRNG, we demonstrate a promising approach for improving the security of printable and flexible electronics.

17.
ACS Nano ; 11(3): 2992-3000, 2017 03 28.
Artigo em Inglês | MEDLINE | ID: mdl-28212000

RESUMO

Increasingly complex demonstrations of integrated circuit elements based on semiconducting single-walled carbon nanotubes (SWCNTs) mark the maturation of this technology for use in next-generation electronics. In particular, organic materials have recently been leveraged as dopant and encapsulation layers to enable stable SWCNT-based rail-to-rail, low-power complementary metal-oxide-semiconductor (CMOS) logic circuits. To explore the limits of this technology in extreme environments, here we study total ionizing dose (TID) effects in enhancement-mode SWCNT-CMOS inverters that employ organic doping and encapsulation layers. Details of the evolution of the device transport properties are revealed by in situ and in operando measurements, identifying n-type transistors as the more TID-sensitive component of the CMOS system with over an order of magnitude larger degradation of the static power dissipation. To further improve device stability, radiation-hardening approaches are explored, resulting in the observation that SWNCT-CMOS circuits are TID-hard under dynamic bias operation. Overall, this work reveals conditions under which SWCNTs can be employed for radiation-hard integrated circuits, thus presenting significant potential for next-generation satellite and space applications.

18.
Repert. med. cir ; 26(1): 35-38, 2017.
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: biblio-859059

RESUMO

Las parálisis periódicas primarias son canalopatías poco frecuentes, de las cuales hacen parte: la parálisis periódica hipocalémica, la parálisis periódica hipercalémica y el síndrome Andersen-Tawil; son caracterizadas por ataques de debilidad muscular generalizada, con recuperación de la fuerza entre los ataques. Presentamos el caso de una mujer de 21 años con el segundo episodio de parálisis y documentación de hipocalemia, sin antecedentes de importancia, sin factores clínicos o paraclínicos que expliquen el trastorno electrolítico, con recuperación posterior de la fuerza al realizar tratamiento de la hipocalemia. Posteriormente se lleva a cabo una revisión del tema.


Primary periodic paralyses are rare channelopathies which include: hypokalemic periodic paralysis, hyperkalemic periodic paralysis, and Andersen-Tawil Syndrome. These entities are characterized by attacks of generalized muscle weakness and recovery of muscle strength between attacks. A case is presented of a 21-year-old woman who presented a second episode of paralysis and documented hypokalemia, with no important antecedents, with no clinical or diagnostic test factors which explain her electrolyte disorder, with recovery of muscle strength after receiving treatment for hypokalemia. A review of the topic was conducted.


Assuntos
Humanos , Feminino , Adulto Jovem , Paralisias Periódicas Familiares , Paralisia Periódica Hipopotassêmica , Canalopatias
19.
Acta méd. colomb ; 40(1): 30-35, ene.-mar. 2015. ilus, tab
Artigo em Espanhol | LILACS, COLNAL | ID: lil-755565

RESUMO

Objetivo: describir las alteraciones ecocardiográficas de los pacientes con acromegalia del Servicio de Endocrinología del Hospital de San José. Metodología: serie de casos de pacientes que asistieron a la clínica de acromegalia del servicio. Se hizo una descripción de las características clínicas relacionadas con la patología de base y sus comorbilidades. El compromiso cardiaco se documentó mediante la toma de electrocardiograma, evaluando arritmias y la evaluación del QT prolongado. El estudio por ecocardiografía transtorácica identificó la fracción de eyección ventricular izquierda, la disfunción valvular, hipertensión pulmonar y el trastorno segmentario de la motilidad ventricular. Resultados: se obtuvo información de 26 pacientes, 69% sexo femenino, 61% mayores de 50 años, con una mediana de evolución de la enfermedad de cinco años. El 92% presentaba macroadenoma, la mayoría de ellos llevados a cirugía. En 21 reportes ecocardiográficos se identificó que 61% de pacientes tenía FEVI mayor a 60% y ninguno de ellos presentó FEVI menor a 45%; 38% de pacientes presentaba hipertrofia ventricular izquierda. La disfunción diastólica fue reportada en 21%, insuficiencia mitral leve en 14%, estenosis aórtica leve en 4%. Se realizaron 24 electrocardiogramas todos con evidencia de ritmo sinusal, extrasístoles ventriculares en 12.5%, sin prolongación del intervalo QT. Conclusión: no se detectó compromiso en la fracción de eyección ni trastornos de motilidad y hubo una baja frecuencia de disfunción diastólica; la hipertrofia ventricular y las alteraciones valvulares fueron menos frecuentes a lo reportado en la literatura y se documentaron extrasístoles ventriculares como única alteración electrocardiográfica. (Acta Med Colomb 2015; 40: 30-35).


Objective: to describe echocardiographic abnormalities in patients with acromegaly in the Hospital San José, Endocrinology Service. Methodology: case series of patients who attended the service acromegaly clinic. A description of the clinical features related to the underlying disease and its comorbidities was made. Cardiac involvement was documented by electrocardiogram, evaluating arrhythmias and prolonged QT. The study by transthoracic echocardiography identified left ventricular ejection fraction, valve dysfunction, pulmonary hypertension and ventricular segmental motility disorder. Results: data of 26 patients was obtained. 69% female, 61% over 50 years, with a median disease progression of five years. 92% showed macroadenoma and most of them underwent surgery. In 21 echocardiographic reports 61% of patients had LVEF greater than 60% and none had LVEF less than 45%; 38% of patients had left ventricular hypertrophy. Diastolic dysfunction was reported in 21%, mild mitral insufficiency in 14%, mild aortic stenosis in 4%. 24 electrocardiograms were performed, all with evidence of sinus rhythm, premature ventricular contractions in 12.5% without QT prolongation. Conclusion: no compromise on ejection fraction or motility disorders were detected and there was a low frequency of diastolic dysfunction; ventricular hypertrophy and valvular abnormalities were less frequent than that reported in the literature and ventricular premature beats as a single electrocardiographic abnormality were documented. (Acta Med Colomb 2015; 40: 30-35).


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Acromegalia , Ecocardiografia , Hormônio do Crescimento Humano , Fatores de Risco de Doenças Cardíacas , Cardiopatias
20.
Repert. med. cir ; 24(2): 152-156, 2015. tab
Artigo em Inglês, Espanhol | LILACS, COLNAL | ID: lil-795713

RESUMO

El feocromocitoma es una neoplasia neuroendocrina de células cromafines que biosintetiza, almacena, metaboliza y secreta concentraciones elevadas de catecolaminas y sus metabolitos. La incidencia es de dos a ocho casos por millón y es frecuente en la cuarta y quinta décadas de la vida. Presentación del caso: mujer de 19 años con cifras tensionales elevadas en controles médicos por antecedente de asma desde la niñez, que se estudia con análisis bioquímicos y TAC abdominal. Se llevó a cirugía ante la sospecha de un tumor adrenal y la neoplasia se caracteriza en el servicio de patología. Conclusiones: el diagnóstico de feocromocitoma y paragangliomas simpáticos que sintetizan y secretan catecolaminas (adrenalina, noradrenalina y dopamina) se basa en el examen físico y el estudio analítico; el principal síntoma es hipertensión arterial. El tratamiento es quirúrgico con curación completa en más del 90%...


Pheochromocytomas are neuroendocrine cromaffin cell tumors which synthetize store, and secrete high concentrations of catecholamines and their metabolytes. Incidence is two to eight cases per million and they are most common in the fourth and fifth decades of life. Case report: a 19-year-old woman with high blood pressure levels in medical follow-ups for presenting asthma since her childhood. She is studied by biochemical analyses and abdominal CT scan. She undergoes surgery due to suspicion of an adrenal tumor and the surgical specimen is characterized in the pathology service. Conclusions: the diagnosis of pheochromocytoma and simpathetic paragangliomas which synthetize and secrete catecholamines (adrenaline, noradrenaline and dopamine) is based on physical exam and complete analyses; the main symptom is arterial hypertension. Surgery is the basis of therapy with complete healing in more than 90% of cases...


Assuntos
Humanos , Feminino , Adulto Jovem , Feocromocitoma , Glândulas Suprarrenais , Hipertensão , Paraganglioma
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...