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1.
Chemphyschem ; 20(15): 1908-1911, 2019 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-31207038

RESUMO

The purpose of this research idea is to develop a method to electrochemically convert carbon dioxide into higher alcohol chains such as ethanol to be used as fuel. Electrochemical CO2 reduction has low yields and poor product selectivity, being able to improve this reaction would have an impact in the energy and food market. We propose the use of a modified nanofluidic transistor to block reaction steps that are thermodynamically favored by constraining the kinetics of the reaction when the reaction takes place in a geometrically restricted environment with different double layer properties to those found in conventional planar electrosynthesis.

2.
Chemphyschem ; 20(22): 3147-3153, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31173447

RESUMO

We demonstrate a fit-for-purpose accelerated durability test (ADT) of a high-surface-area catalyst for the alkaline oxygen evolution reaction (OER). Using an automatized electrochemical setup enabled us to run a complex ADT protocol including online detection of the effective solution resistance as well as linear voltammetry, cyclic voltammetry, cyclic galvanograms, and electrochemical impedance spectroscopy (EIS) for 55 h in total. Using this protocol, we tested the service life stability of a nickel oxyhydroxide (NiOx) catalyst based on Raney Ni. The catalyst was prepared by growing nickel oxyhydroxide on high-surface-area Raney Ni and subsequent formation of the active phase. The successful synthesis of the active NiOx phase is supported by cyclic voltammetry and Raman spectroscopy. The as prepared and activated Raney NiOx exhibits an overpotential for the OER of 304 mV at 10 mA cm-2 with a Tafel slope of 53 mV dec-1 and roughness factors as high as 4515 determined by EIS during OER. By concentrating for the ADT protocol on current densities relevant for coupling water electrolysis to photovoltaics, it is demonstrated that Raney NiOx is a promising anode material candidate as it is earth abundant and its active phase exhibits high OER activity as well as stability.

3.
Acta neurol. colomb ; 39(4)dic. 2023.
Artigo em Espanhol | LILACS | ID: biblio-1533511

RESUMO

Introducción: El síndrome de Balint es un trastorno neurológico infrecuente, de etiología diversa, cuya presentación incluye la triada clásica de: simultagnosia, ataxia óptica y apraxia oculomotora, síntomas secundarios asociados a lesiones parieto-occipitales, con pronóstico variable según la etiología que se encuentre. A continuación, se reporta un caso secundario a una trombosis de senos venosos. Presentación del caso: Mujer de 66 años que ingresa a urgencias por cefalea aguda asociada a síntomas neurológicos progresivos con compromiso visual. Presentó tensión arterial elevada, simultagnosia, ataxia óptica y apraxia oculomotora. Los estudios imagenológicos reportaron hemorragia subaracnoidea por trombosis de seno sigmoideo izquierdo, por lo que se inició anticoagulación, antihipertensivo, con adecuada evolución del cuadro clínico. Discusión: A pesar de que el síndrome de Balint es un trastorno poco común, de etiología diversa, con escasos reportes a escala global, el caso comentado concordó con las características descritas en la literatura. El abordaje de la paciente en su atención inicial permitió la sospecha diagnóstica oportuna y la indicación de ayudas diagnósticas imagenológicas pertinentes. Tales ayudas soportaron un manejo temprano y la adecuada evolución y resolución del cuadro, en el contexto de la asociación del síndrome a una trombosis de senos venosos cerebrales (una etiología infrecuente). Conclusión: Mediante una historia clínica completa y minuciosa, junto a un adecuado examen neurológico, es posible hacer un acercamiento diagnóstico temprano que permita generar la sospecha del síndrome de Balint y la solicitud temprana de imágenes diagnósticas que orienten en el estudio de su etiología y manejo oportuno, con mejores desenlaces en el paciente.


Introduction: Balint Syndrome is a rare neurological disorder with multiple etiologies. The physical signs include a classic triad (simultagnosia, optic ataxia, and oculomotor apraxia). These symptoms are associated with parieto-occipital lesions, and the prognosis depends on the etiology. This article reports a case secondary to venous sinus thrombosis. Presentation of the case: A 66-year-old woman presented to the emergency room with acute headache associated with progressive neurological symptoms and visual impairment. She had high blood pressure, simultanagnosia, optic ataxia, and oculomotor apraxia. Imaging studies revealed subarachnoid hemorrhage due to thrombosis of the left sigmoid sinus, for which anticoagulation and antihypertensive therapy were started. The patient had a favorable clinical outcome. Discussion: Although Balint syndrome is a rare disorder of diverse etiology with few clinical cases reported globally, the case discussed here was consistent with the characteristics described in the literature. The patient's initial assessment allowed for timely diagnostic suspicion and appropriate imaging studies, which supported early management and the appropriate evolution and resolution of the condition, given the association of the syndrome with an uncommon cause as cerebral venous sinus thrombosis. Conclusion: A complete and thorough medical history, along with a proper neurological exam, can lead to an early diagnostic approach that raises suspicion of Balint's syndrome and prompts timely imaging studies to guide the investigation of its etiology and management, ultimately leading to better outcomes for the patient.


Assuntos
Transtornos da Personalidade , Transtornos da Visão , Trombose Venosa , Agnosia , Síndrome , Exame Neurológico
4.
Univ. salud ; 24(1): 102-107, ene.-abr. 2022. tab, graf
Artigo em Espanhol | LILACS, COLNAL | ID: biblio-1361191

RESUMO

Introducción: La enfermedad de cambios mínimos es una causa rara de síndrome nefrótico en el adulto, y su relación con el hipotiroidismo es más rara aún. Se considera que esta patología renal responde favorablemente al manejo con glucocorticoides y tiene una baja frecuencia de resistencia. Su abordaje hoy en día es objeto de investigación. Objetivo: Describir una rara etiología de síndrome nefrótico en el adulto con presentación, tratamiento y desenlace infrecuentes. Presentación del caso: Paciente femenino de 53 años quien inicia con síndrome nefrótico por enfermedad de cambios mínimos cortico-resistente y su asociación con un hipotiroidismo descontrolado, quien requiere manejo con rituximab y control de la enfermedad endocrinológica asociada, como enfermedad de base. Conclusiones: En este caso clínico se muestra como las enfermedades citadas pueden coexistir y el tratamiento en conjunto es necesario. El establecimiento de nuevas terapias en la población adulta como el rituximab podría mostrar beneficio, como en este caso. Sin embargo, aún existe la necesidad de estudios de mayor evidencia que validen firmemente la efectividad de los diferentes tratamientos en este tipo de pacientes.


Introduction: Minimal change disease is a rare cause of nephrotic syndrome in adults, and its association with hypothyroidism is even more exceptional. This renal pathology is considered to respond favorably to glucocorticoid management and has a low resistance frequency. How to approach this disease is currently under investigation. Objective: To describe a rare etiology of adult nephrotic syndrome with unusual presentation, treatment, and outcome. Case presentation: A 53 years-old female patient who initially experienced nephrotic syndrome due to steroid-resistant minimal change disease, which was also associated with uncontrolled hypothyroidism. She required management with rituximab and control of the associated endocrinological disease, which was considered as the underlying disease. Conclusions: This clinical case shows (i) how the two aforementioned diseases can coexist and (ii) that a joint treatment is necessary. Establishing new therapies may be beneficial for adult populations, such as the benefits seen in this case with the use of rituximab. However, further studies are needed to strongly validate the effectiveness of the different treatments for these types of patients.


Assuntos
Humanos , Pessoa de Meia-Idade , Doenças da Glândula Tireoide , Nefrose , Hipotireoidismo , Nefrose Lipoide , Síndrome Nefrótica
5.
Med. UIS ; 35(2): e504, mayo-ago. 2022. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1422053

RESUMO

Resumen La fístula carótido-cavernosa es cualquier comunicación anómala entre la arteria carótida y el seno cavernoso que genera un shunt arteriovenoso patológico, se manifiesta en forma anterógrada a la órbita, causa ceguera y oftalmoparesia. Su asociación con trauma craneoencefálico leve es escasa y poco reportada, por lo que se desconoce su prevalencia. Se reporta un paciente masculino de 54 años proveniente de Cali, Colombia, con antecedente de trauma craneoencefálico leve 2 meses antes del ingreso, quien presenta cuadro de cefalea holocraneal y alteraciones visuales. Al examen físico presentó oftalmoparesia, con ptosis palpebral bilateral asimétrica y proptosis pulsátil izquierda; se realizó resonancia magnética cerebral simple y angioresonancia, con hallazgos sugestivos de fístula carótido-cavernosa. El paciente fue llevado a arteriografía más embolización, logrando un resultado favorable. La presencia de cefalea con banderas rojas, alteraciones visuales, proptosis pulsátil y el antecedente de trauma craneoencefálico, sin importar su grado, pueden hacer sospechar la presencia de esta entidad.


Abstract The carotid-cavernous fistula is any abnormal communication between the carotid artery and the cavernous sinus, generating a pathological arteriovenous shunt manifesting anterograde to the orbit, causing blindness and ophthalmoparesis. Its association with mild head trauma is scarce and underreported, its prevalence being unknown. A 54-year-old male patient from Cali - Colombia is reported, with a history of mild cranioencephalic trauma 2 months ago, who consulted for a holocranial headache and visual disturbances. On physical examination he presented ophthalmoparesis, with bilateral asymmetric palpebral ptosis with left pulsatile proptosis. A simple brain magnetic resonance and angio-MRI was performed, with findings suggestive of a carotid-cavernous fistula. The patient was taken to arteriography plus embolization, achieving a favorable result. The presence of headache with red flags, visual disturbances, pulsatile proptosis, and a history of head trauma, regardless of its degree, can lead to suspect the presence of this entity.


Assuntos
Humanos , Pessoa de Meia-Idade
6.
Sci Rep ; 5: 15208, 2015 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-26469204

RESUMO

An efficient electrocatalyst comprising inexpensive and earth-abundant materials for the oxygen evolution reaction (OER) is crucial for the development of water electrolysis. In this work, in-situ addition of cobalt/molybdenum ions to the electrolytic manganese dioxide has been shown to be beneficial for the OER in acid solution as its overpotential performed better (305 mV) than that of the commercial DSA(®) (341 mV) at 100 mA cm(-2). The OER was investigated at ambient temperature in 2 M H2SO4 solution on the modified EMD (MnMoCoO) electrodes. The energy efficiency of the MnMoCoO electrodes improved significantly with the amount of Co in the plating solution. For the electrodeposited catalysts, physico-chemical and electrochemical measurements were conducted including static overpotentials. The better performance of the modified EMD was attributed to an improved charge transfer resistance (Rct; 0.290 Ω cm(2)), average roughness factor (rf; 429) and decrease in water content in the electrodeposited catalysts. The kinetic parameters obtained on MnMoCoO catalysts were compared and discussed according to the cobalt concentration.

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