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Given their intriguing properties, porous carbons have surfaced as promising electrocatalysts for various energy conversion reactions. This study presents a unique approach where iron-cobalt (FeCo) is confined in a boron, nitrogen-doped chitosan-derived porous carbon aerogel (BNPC-FeCo) to serve as an electrocatalyst for the hydrogen evolution and oxygen evolution reactions (HER and OER). The BNPC-FeCo-900 electrocatalyst demonstrates excellent catalyst activity, with very low overpotentials of 186 and 320 mV at 10 mA cm-2, low Tafel slopes of 82 and 55 mV dec-1, and low charge transfer resistance of 2.68 and 9.25 Ω for HER and OER, respectively. Density functional theory (DFT) calculations further reveal that the cooperation between the boron, nitrogen codoped porous carbon, and the FeCo nanoparticles reduces intermediates' energy barriers, significantly enhancing the HER and OER performance. In conclusion, this work offers significant and informative perspectives into the potential of porous carbon materials as dual-purpose electrocatalysts for water splitting.
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Increased Aurora B protein expression, which is common in cancers, is expected to increase Aurora B kinase activity, yielding elevated phosphorylation of Aurora B substrates. In contrast, here we show that elevated expression of Aurora B reduces phosphorylation of six different Aurora B substrates across three species and causes defects consistent with Aurora B inhibition. Complexes of Aurora B and its binding partner INCENP autophosphorylate in trans to achieve full Aurora B activation. Increased expression of Aurora B mislocalizes INCENP, reducing the local concentration of Aurora B:INCENP complexes at the inner centromere/kinetochore. Co-expression of INCENP rescues Aurora B kinase activity and mitotic defects caused by elevated Aurora B. However, INCENP expression is not elevated in concert with Aurora B in breast cancer, and increased expression of Aurora B causes resistance rather than hypersensitivity to Aurora B inhibitors. Thus, increased Aurora B expression reduces, rather than increases, Aurora B kinase activity.
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INTRODUCTION: Cervical cancer is the second most common female cancer in Ghana. The disease and its treatment significantly affect survivors' health-related quality of life (HRQoL). We determined the overall quality of life (QoL) and identified its predictors among cervical cancer survivors after treatment. MATERIALS AND METHODS: A hospital-based cross-sectional analytical study was conducted on 153 disease-free cervical cancer survivors who completed curative treatment between January 2004 and December 2018 at Komfo Anokye Teaching Hospital (KATH) in Kumasi, Ghana. We used the European Organization for Research and Treatment of Cancer core-30 item (EORTC QLQ-C30) and cervical cancer module (EORTC QLQ-CX24) to assess the survivors' overall QoL. QoL domain scores were dichotomised as affected or unaffected by disease and its treatment. Significant differences between the affected and unaffected groups within each QoL domain were determined using the student T-test. We used Kruskal-Wallis and Dunn's tests to examine the difference in QoL domains between treatment types, with significance based on Bonferroni corrections. Multivariable logistic regression was performed to identify predictors of overall QoL. A p-value of less than 0.05 was considered statistically significant. RESULTS: One hundred and fifty-three (153) women having a mean age of 58.3 (SD 11.4) years were studied. The overall QoL score was 79.6 (SD 16.0), and 74.5% of survivors reported good QoL score within the median follow up time of 41.8 months (interquartile range [IQR], 25.5-71.1 months) after cervical cancer diagnosis. Although the majority (66.0-84.3%) of the QoL functioning scale were unaffected, about a fifth (22.2%) to a third (34.5%) of the subjects had perceptual impairment in cognitive and role functioning. Financial difficulties, peripheral neuropathy and pain were most common symptoms reported as affected. A third of the survivors were worried that sex would be painful, and 36.6% indicated that their sexual activity as affected. The overall QoL scores for survivors who had surgery, chemoradiation and radiation-alone were 86.1 (SD 9.7), 76.9 (SD 17.7), and 80.7 (SD 14.7), respectively (p = 0.025). The predictors of survivor's overall QoL were loss of appetite [Adjusted Odd Ratio (AOR) = 9.34, 95% Confidence Interval (CI) = 2.13-35.8, p = 0.001], pain (AOR = 3.53, 95% CI = 1.25-9.31, p = 0.017) and body image (AOR = 5.89, 95% CI = 1.80-19.27, p = 0.003). CONCLUSION: About 75% of the survivors had a good overall quality of life. Primary surgical treatment affords the best prospects for quality of life with the least symptom complaints and financial burden. Loss of appetite, pain or diminution in body image perception predicted the overall quality of life of cervical cancer survivors after treatment.
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Sobreviventes de Câncer , Neoplasias do Colo do Útero , Sobreviventes de Câncer/psicologia , Estudos Transversais , Feminino , Gana/epidemiologia , Humanos , Pessoa de Meia-Idade , Dor , Qualidade de Vida , Inquéritos e Questionários , Sobreviventes , Centros de Atenção Terciária , Neoplasias do Colo do Útero/psicologia , Neoplasias do Colo do Útero/terapiaRESUMO
The electrocatalytic performance of oxygen evolution reaction (OER) electrocatalysts is highly reliant on the activity of its catalytic active site, which may be augmented by raising the number of active sites. In this study, nanoscaled nickel-cobalt-iron (NiCoFe) alloy was embedded on conductive boron(B), nitrogen(N) co-doped/biomass-derived carbon aerogel as an OER electrocatalyst. The synthesized electrocatalysts were calcined under different temperatures and with variable dopants. The optimal electrocatalyst (BN/CA-NiCoFe-600) demonstrated a low overpotential of 321 mV (at current density of 10 mA cm-2) and a minute Tafel slope of 42 mV dec-1, which was even smaller than that of IrO2 and RuO2. Its mass activity and specific activity were calculated to be 201.7 A g-1, and 34.1 cm-2ECSA, respectively. Furthermore, the electrocatalyst showed excellent stability and durability. This work provides an easy and practical synthetic strategy for acquiring very active and durable electrocatalysts for OER.
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Cobalto , Nanopartículas , Biomassa , Boro , Carbono , Ferro , Níquel , Nitrogênio , OxigênioRESUMO
La prevalencia y severidad del asma en niños está en aumento en diversos países del mundo, sin embargo es poco lo que se conoce en nuestro país, por lo que es importante evaluar la tendencia de esta enfermedad en Lima. El presente es un estudio epidemiológico que describe la prevalencia y severidad de síntomas sugerentes de asma en niños escolares de 13-14 años del distrito de Santiago de Surco, Lima, mediante el cuestionario estándar del International Study of Asthma and Allergies in Childhood (ISAAC). Se empleó un muestreo aleatorio simple, considerando como unidad muestral a todos los colegios registrados en la USE-10. Se entrevistaron a un total de 3174 niños, siendo retirados 37 cuestionarios, por lo que el tamaño muestral final fue de 3137 niños. Se reporta una prevalencia de asma de 26.0 por ciento; el 24 por ciento tenían el antecedente de haber sido diagnósticados por un médico alguna vez. De los 814 niños que presentaron sibilancias recurrentes, el 70.8 por ciento reportaron la presencia de asma inducida por el ejercicio y el 42.8 por ciento reportaron la presencia de tos nocturna. Finalmente el 6.7 por ciento reportaron episodios severos de broncoespamo. Los datos que presentamos nos indican que el asma es una enfermedad altamente prevalente en Lima, que amerita nuestra atención por ser un importante problema de salud pública. Estudios posteriores podrán determinar cuáles son los factores que intervienen en su presentación. Palabras clave: Asma, prevalencia, niños, ISAAC.
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Adolescente , Asma , Prevalência , Estudantes , Estudos TransversaisRESUMO
La prevalecencia y severidad de las enfermedades alérgicas han mostrado un incremento desde principios de la década del 70. Muchos son los grupos que se han formado en el mundo para estudiar estos fenómenos pero son más los trabajos publicados por estos mismos. En este artículo se presenta algunos de los estudios más importantes en torno a una de las enfermedades más frecuentes en dermatologia pediátrica : dermatitis atópica. Se revisan algunos conceptos epidemiológicos, de diagnostico, así como los factores de riesgo relacionados con esta frecuente enfermedad
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Humanos , Dermatite Atópica/diagnóstico , Dermatite , DermatologiaRESUMO
La definición de asma ha cambiado con los años, actualmente existe interés en poder evaluar desde un punto de vista epidemiológico qué está sucediendo con esta enfermedad. La comparación de prevalencias entre diferentes poblaciones es discutida en esta revisión. Es importante considerar el método utilizado, el conocimiento de la comunidad sobre la enfermedad, la edad a evaluar y otros factores más; se presentan diferentes prevalencias alrededor del mundo, incluyendo un estudio nacional.