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A new paradigm for energy is underway demanding decarbonized energy systems. Some of them rely on emerging electrochemical devices, crucial in hydrogen technologies, including fuel cells, CO2 and water electrolysers, whose applications and performances depend on key components such as their separators/ion-exchange membranes. The most studied and already commercialized Nafion membrane shows great chemical stability, but its water content limits its high proton conduction to a limited range of operating temperatures. Here, we report the synthesis of a new series of triazinephosphonate derivatives and their use as dopants in the preparation of new modified Nafion membranes. The triazinephosphonate derivatives were prepared by substitution of chlorine atoms in cyanuric chloride. Diverse conditions were used to obtain the trisubstituted (4-hydroxyphenyl)triazinephosphonate derivatives and the (4-aminophenyl)triazinephosphonate derivatives, but with these amino counterparts, only the disubstituted compounds were obtained. The new modified Nafion membranes were prepared by casting incorporation of the synthesized 1,3,5-triazinephosphonate (TPs) derivatives. The evaluation of the proton conduction properties of the new membranes and relative humidity (RH) conditions and at 60 °C, showed that they present higher proton conductivities than the prepared Nafion membrane and similar or better proton conductivities than commercial Nafion N115, in the same experimental conditions. The Nafion-doped membrane with compound TP2 with a 1.0 wt % loading showed the highest proton conductivity with 84 mS·cm-1.
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Purpose: The main purpose of this study was to report a case of cystoid macular edema (CME) after gonioscopy-assisted transluminal trabeculotomy (GATT). Methods: We describe the case of a 73-year-old woman with ocular hypertension and history of cataract surgery combined with posterior vitrectomy and epiretinal membrane peeling 2 years before, who developed CME after uncomplicated GATT procedure. Results: Uneventful GATT surgery was performed in an eye with ocular hypertension. A month after GATT surgery, the patient com-plained of blurry vision. Best corrected visual acuity had deteriorated from 20/20 on Snellen chart, to 20/70. The patient was diagnosed with CME. Treatment with topical non-steroidal anti-inflammatory drug (NSAID) and topical corticosteroids for one month, and oral carbonic anhydrase inhibitor for one week achieved a total CME regression with recovery of a normal macular and foveal architecture. Conclusions: Surgery-induced CME may occur following stand-alone microinvasive glaucoma surgery (MIGS) such as GATT. It would be worthwhile to conduct studies to explore whether the prophylactic use of NSAID and corticosteroids is justified.
Asunto(s)
Glaucoma de Ángulo Abierto , Edema Macular , Hipertensión Ocular , Trabeculectomía , Corticoesteroides/efectos adversos , Anciano , Antiinflamatorios no Esteroideos , Femenino , Estudios de Seguimiento , Glaucoma de Ángulo Abierto/complicaciones , Glaucoma de Ángulo Abierto/diagnóstico , Glaucoma de Ángulo Abierto/cirugía , Gonioscopía , Humanos , Presión Intraocular , Edema Macular/etiología , Estudios Retrospectivos , Trabeculectomía/efectos adversos , Trabeculectomía/métodosRESUMEN
Full-thickness macular hole is a rare complication of macular telangiectasia type 2, and its treatment is still controversial. A patient with a full-thickness macular hole secondary to macular telangiectasia type 2 underwent vitreoretinal surgery with a plasma rich in growth factors membrane in the macular hole. At the sixth month of follow-up, anatomical and functional improvements were achieved, with no adverse effects. Plasma rich in growth factors is a new option, with advantages due to its biological properties that achieves good results in terms of safety and effectiveness in the surgical treatment of macular hole.
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Perforaciones de la Retina , Telangiectasia Retiniana , Humanos , Perforaciones de la Retina/etiología , Perforaciones de la Retina/cirugía , Telangiectasia Retiniana/complicaciones , Telangiectasia Retiniana/terapia , Vitrectomía/métodosRESUMEN
El agujero macular de espesor total es una complicación rara de la telangiectasia macular tipo 2, y su tratamiento es aún controvertido. Una paciente con esta entidad fue llevada a cirugía vitreorretiniana con aplicación de membrana de plasma rico en factores de crecimiento sobre el agujero macular. Al sexto mes de cirugía se logró mejoría anatómica y funcional, sin efectos adversos asociados. El plasma rico en factores de crecimiento es una alternativa nueva en el tratamiento quirúrgico del agujero macular atípico y/o persistente, que logra buenos resultados en términos de seguridad efectividad, debido a sus propiedades biológicas (AU)
Full-thickness macular hole is a rare complication of macular telangiectasia type 2, and its treatment is still controversial. A patient with a full-thickness macular hole secondary to macular telangiectasia type 2 underwent vitreoretinal surgery with a plasma rich in growth factors membrane in the macular hole. At the sixth month of follow-up, anatomical and functional improvements were achieved, with no adverse effects. Plasma rich in growth factors is a new option, with advantages due to its biological properties that achieves good results in terms of safety and effectiveness in the surgical treatment of macular holey (AU)
Asunto(s)
Humanos , Femenino , Anciano , Perforaciones de la Retina/etiología , Perforaciones de la Retina/cirugía , Telangiectasia Retiniana/complicaciones , Cirugía Vitreorretiniana/métodos , Factores de Crecimiento Transformadores/administración & dosificación , Plasma , Resultado del TratamientoRESUMEN
Objetivo Publicar las manifestaciones oculares en paciente con leucemia. Métodos Estudio observacional analítico de corte transversal, en pacientes con manifestaciones oculares por leucemia. Resultados Se evaluaron 14 ojos de 8 pacientes (5 mujeres y 3 varones) con leucemia. La edad promedio al diagnóstico de leucemia fue de 43 años (31-76 años). Seis ojos correspondían a pacientes con leucemia mieloide aguda (LMA), 4 ojos a pacientes con leucemia linfoide aguda (LLA), 2 ojos a pacientes con leucemia mieloide crónica (LMC) y 2 ojos a pacientes con leucemia de células peludas (LCP). Los hallazgos oculares primarios fueron: invasión coroidea en 12 ojos (85,7%), infiltración retiniana en 4 ojos (28,6%) y desórdenes neuroftalmológicos en 4 ojos (28,6%). La agudeza visual promedio mejoró de 0,689 a 0,449 logMAR (p 0,012) luego del tratamiento con quimioterapia sistémica e intratecal. De los 8 pacientes, 4 murieron debido a complicaciones de su enfermedad. Conclusiones Este es el primer artículo de múltiples manifestaciones oculares secundaria a leucemia en una población colombiana. Es importante tener en cuenta que este tipo de manifestaciones hacen parte de los síndromes de enmascaramiento por lo tanto es primordial hacer un diagnóstico y manejo precoz ya que en ocasiones está en riesgo la vida del paciente (AU)
Objective To report the ocular manifestations in patients with leukaemia. Methods This is a retrospective, descriptive and observational study in patients with ocular manifestations of leukaemia. Results A total of 14 eyes were evaluated corresponding to 8 patients (5 women and 3 men) with ocular manifestations of leukaemia. The mean age at diagnosis was 43 years (31-76 years). Six eyes corresponded to patients with acute myeloid leukaemia (AML), four eyes to acute lymphoid leukaemia (ALL), two eyes to chronic myeloid leukaemia (CML), and the remaining two belonged to patients with hairy cell leukaemia (HCL). The primary ocular findings were choroidal invasion in 12 eyes (85.7%), retinal infiltration in 4 eyes (28.6%), and neuro-ophthalmic disorders in 4 eyes (28.6%). The mean visual acuity improved from 0.689 to 0.449 (logMAR) (P=.012) after the systemic and intrathecal chemotherapy. Of the eight patients, four died from systemic complications of the underlying disease. Conclusions This is the first report of multiple ocular manifestations secondary to leukaemia in a Colombian population. It is important to keep in mind that this disease is included within the masquerade syndromes and that the ophthalmological findings that, while subtle, can also be devastating and be signs of a life-threatening disease (AU)
Asunto(s)
Humanos , Masculino , Femenino , Adulto , Persona de Mediana Edad , Anciano , Leucemia/complicaciones , Oftalmopatías/etiología , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Colombia , Estudios Transversales , Agudeza VisualRESUMEN
Full-thickness macular hole is a rare complication of macular telangiectasia type 2, and its treatment is still controversial. A patient with a full-thickness macular hole secondary to macular telangiectasia type 2 underwent vitreoretinal surgery with a plasma rich in growth factors membrane in the macular hole. At the sixth month of follow-up, anatomical and functional improvements were achieved, with no adverse effects. Plasma rich in growth factors is a new option, with advantages due to its biological properties that achieves good results in terms of safety and effectiveness in the surgical treatment of macular hole.
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OBJECTIVE: To report the ocular manifestations in patients with leukaemia. METHODS: This is a retrospective, descriptive and observational study in patients with ocular manifestations of leukaemia. RESULTS: A total of 14 eyes were evaluated corresponding to 8 patients (5 women and 3 men) with ocular manifestations of leukaemia. The mean age at diagnosis was 43 years (31-76 years). Six eyes corresponded to patients with acute myeloid leukaemia (AML), four eyes to acute lymphoid leukaemia (ALL), two eyes to chronic myeloid leukaemia (CML), and the remaining two belonged to patients with hairy cell leukaemia (HCL). The primary ocular findings were choroidal invasion in 12 eyes (85.7%), retinal infiltration in 4 eyes (28.6%), and neuro-ophthalmic disorders in 4 eyes (28.6%). The mean visual acuity improved from 0.689 to 0.449 (logMAR) (P=.012) after the systemic and intrathecal chemotherapy. Of the eight patients, four died from systemic complications of the underlying disease. CONCLUSIONS: This is the first report of multiple ocular manifestations secondary to leukaemia in a Colombian population. It is important to keep in mind that this disease is included within the masquerade syndromes and that the ophthalmological findings that, while subtle, can also be devastating and be signs of a life-threatening disease.
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In pursuit of the ideal photocatalyst, cheap and stable semiconductor TiO2 is considered to be a good choice if one is able to reduce its band gap and decrease the recombination rate of charge carriers. The approach that offers such improvements for energy conversion applications is the modification of TiO2 with nitrogen and noble metals. However, the origin of these improvements and possibilities for further design of single-atom catalysts are not always straightforward. To shed light on the atomic-scale picture, we modeled the nitrogen-doped (001) anatase TiO2 surface as a support for palladium and platinum single-atom deposition. The thermodynamics of various synthesis routes for Pd/Pt deposition and nitrogen doping is considered based on density functional theory (DFT)-calculated energies, highlighting the effect of nitrogen doping on metal dimer formation and metal-support interaction. XPS analysis of the valence band of the modified TiO2 nanocrystals, and the calculated charge transfer and electronic structure of single-atom catalysts supported on the (001) anatase TiO2 surface provide an insight into modifications occurring in the valence zone of TiO2 due to nitrogen doping and Pd/Pt deposition at the surface. DFT results also show that substitutional nitrogen doping significantly increases metal-support interaction, while interstitial nitrogen doping promotes only Pt-support interaction.
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Nitrogen-doped TiO2 (N-TiO2) is considered as one of the most promising materials for various photocatalytic applications, while noble metals Pd and Pt are known as good catalysts for hydrogen evolution. This work focuses on the determination of structural and electronic modifications of N-TiO2, achieved by noble metal deposition at the surface, as a starting indicator for potential applications. We focus on the properties of easily synthesized nanocrystalline nitrogen-doped anatase TiO2, modified by depositing small amounts of Pd (0.05 wt%) and Pt (0.10 wt%), aiming to demonstrate efficient enhancement of optical properties. The chemical states of dopants are studied in detail, using X-ray photoemission spectroscopy, to address the potential of N-TiO2 to act as a support for metallic nanoparticles. DFT calculations are used to resolve substitutional from interstitial nitrogen doping of anatase TiO2, as well as to study the combined effect of nitrogen doping and oxygen vacancy formation. Based on the binding energies calculated using Slater's transition state theory, dominant contribution to the N 1s binding energy at 399.8 eV is ascribed to interstitially doped nitrogen in anatase TiO2. Given that both structure and photocatalytic properties depend greatly on the synthesis procedure, this work contributes further to establishing correlation between the structure and optical properties of the noble metal modified N-TiO2 system.