RESUMO
The stoichiometry of the components of hexacyanoferrate materials affecting their final porosity properties and applications in CO2 capture is an issue that is rarely studied. In this work, the effect that stoichiometry of all element components and oxidation states of transition metals has on the structures of mesoporous K or Na-cobalt hexacyanoferrates (CoHCFs) and CO2 removal is reported. A series of CoHCFs model systems are synthesized using the co-precipitation method with varying amounts of Co ions. CoHCFs are characterized by N2 adsorption, TGA, FTIR-ATR, XRD, and XPS. N2 adsorption results reveal a more developed external surface area (72.69-172.18 m2/g) generated in samples containing mixtures of K+/Fe2+/Fe3+ ions (system III) compared to samples with Na+/Fe2+ ions (systems I, II). TGA results show that the porous structure of CoHCFs is affected by Fe and Co ions oxidation states, the number of water molecules, and alkali ions. The formation of two crystalline cells (FCC and triclinic) is confirmed by XRD results. Fe and Co oxidation states are authenticated by XPS and allow for the confirmation of charges involved in the stabilization of CoCHFs. CO2 removal capacities (3.04 mmol/g) are comparable with other materials reported. CO2 adsorption kinetics is fast (3-6 s), making CoHCFs attractive for continuous operations. Qst (24.3 kJ/mol) reveals a physical adsorption process. Regeneration effectiveness for adsorption/desorption cycles indicates ~1.6% loss and selectivity (~47) for gas mixtures (CO2:N2 = 15:85). The results of this study demonstrate that the CoHCFs have practical implications in the potential use of CO2 capture and flue gas separations.
RESUMO
Mixtures of a nonionic surfactant and non-functionalized nanohydroxyapatite (NHA) enhanced the stability of oil-in-eutectic mixture high internal phase emulsions (HIPEs). Upon ring opening polymerization of the eutectic mixture composed of l-lactide and ε-caprolactone, biodegradable polyHIPEs with specific cavity sizes and selective interfacial functionalization with NHA are produced.
RESUMO
The droplet phase of a reverse microemulsion formed by the surfactant cetyltrimethylammonium ferrocyanide was used as a matrix to synthesize nanoparticles of nickel hexacyanoferrate by adding just a solution of NiCl2 to the microemulsion media. Dynamic light scattering and small-angle neutron scattering measurements show that the reverse microemulsion droplets employed have a globular structure, with sizes that depend on water content. Transmission electron microscopy and electron diffraction are used to obtain information about the structure of the synthesized nanoparticles. The results show that the size and shape of the coordination compound nanoparticles correspond with the size and shape of the droplets, suggesting that the presented system constitutes an alternative method of the synthesis of metal hexacyanoferrate nanoparticles.
RESUMO
BACKGROUND: Exacerbations of heart failure appear frequently associated with precipitating factors not directly related to the evolution of cardiac disease. There still a paucity of data on the proportional distribution of precipitating factors specifically in elderly patients. The aim of this study was to examine prospectively the precipitating factors leading to hospitalization in elderly patients with heart failure in our community hospital. METHODS: We evaluate elderly patients who need admissions for decompensate heart failure. All patients were reviewed daily by the study investigators at the first 24 h and closely followed-up. Decompensation was defined as the worsening in clinical NYHA class associated with the need for an increase in medical treatment (at minimum intravenously diuretics). RESULTS: We included 102 patients (mean age 79 ± 12 years). Precipitating factors were identified in 88.5%. The decompensation was sudden in 35% of the cases. Noncompliance with diet was identified in 52% of the patients, lack of adherence to the prescribed medications amounted to 30%. Others precipitating factors were infections (29%), arrhythmias (25%), acute coronary ischemia (22%), and uncontrolled hypertension (15%), miscellaneous causes were detected in 18% of the cases (progression of renal disease 60%, anemia 30% and iatrogenic factors 10%). Concomitant cause was not recognizable in 11.5%. CONCLUSIONS: Large proportion heart failure hospitalizations are associated with preventable precipitating factors. Knowledge of potential precipitating factors may help to optimize treatment and provide guidance for patients with heart failure. The presence of potential precipitating factors should be routinely evaluated in patients presenting chronic heart failure.
RESUMO
La mayoría de las personas quieren ser (y parecer) racionales y objetivas a la hora de tomar decisiones, sobre todo en contextos profesionales. Sin embargo, multitud de variables aparentemente irrelevantes pueden sesgar los juicios y los comportamientos de las personas. La presente investigación demuestra que la evaluación de un potencial candidato a un puesto de trabajo en un contexto experimental de selección de personal puede verse influida por la activación previa de estereotipos. En concreto, se pidió a un grupo de participantes que completaran palabras relacionadas con el estereotipo de ejecutivo o de skinhead (cabeza rapada) y, a continuación, se presentó una información ambigua sobre un supuesto candidato a un puesto de trabajo. Tal y como se esperaba, las actitudes y valoraciones hacia el candidato fueron más favorables en el primer caso. En el presente trabajo se discuten los posibles procesos psicológicos subyacentes a este efecto, así como las estrategias de control mental que pueden ayudar a reducir este tipo de sesgos.
Most people want to be (and be seem) rational and objective when making decisions, particularly in professional domains. However, a large number of irrelevant factors can bias judgments and behaviors. The present research reveals that attitudes toward potential job candidates can be influenced by stereotype activation in an experimental context. Specifically, participants were asked to complete words related to the stereotype of businessman or to the stereotype of skinhead prior to receiving ambiguous information about a fictitious job candidate. As predicted, attitudes and perceptions toward the candidate were more favorable in the former than in the later priming condition. Possible underlying psychological mechanisms and strategies for bias reductionare discussed.
Assuntos
Humanos , Atitude , Seleção de PessoalRESUMO
Circannual variation in cardiovascular events is well-known. Seasonal variation (SV) in heart failure (HF) has been described in the Northern Hemisphere, but there is scarcity of data in South America. The goals of the present study were to (1) describe the SV of admissions and deaths for HF, and (2) describe trends in HF morbidity and mortality in a community hospital in Argentina from 1992 to 1999. The study sample included 6369 admissions. During this period, the number of HF admissions rose by 188% and the rate HF admissions/all admissions increased from 3.28% to 7.84%. In-hospital mortality decreased from 21% to 13%. HF admissions followed a seasonal pattern with a winter-spring predominance. Male and very old patients were the subgroups with the highest SV. The authors identified clear SV in HF deaths and admissions, which raises a different hypothesis about the rationale of HF admissions and provides information for the organization of care and resource allocation.
Assuntos
Insuficiência Cardíaca/mortalidade , Hospitais Comunitários , Estações do Ano , Fatores Etários , Idoso , Argentina/epidemiologia , Feminino , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/fisiopatologia , Mortalidade Hospitalar , Hospitalização , Humanos , Masculino , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Fatores Sexuais , Fatores de TempoRESUMO
Se presenta la experiencia inicial en cirugía cardíaca a corazón abierto de un hospital general de 150 camas alejado de un centro universitario. Entre noviembre de 1982 y julio de 1984 fueron operados con circulación extracorpórea 93 pacientes: los 53 coronarios (61,0 años de promedio, 17% mujeres) incluyeron 5 lesiones de tronco y recibieron un promedio de 2,8 puentes por paciente, durante un "clampeo" aórtico promedio de 21 minutos por puente. La protección miocárdica estuvo asegurada por hipotermia general moderada, cardioplejía hipercalémica fría e irrigación continua del pericardio con suero frío. La mortalidad hospitalaria fue del 1,9%. Los 35 valvulares (56,6 años de promedio, 50% mujeres) repartidos en 5 comisurotomías mitrales, 6 reemplazos mitrales aislados, 16 reemplazos aórticos aislados, 4 reemplazos aórticos más puente y 4 dobles reemplazos, recibieron bajo una protección miocárdica similar 19 prótesis mecánicas y 14 biológicas, con una mortalidad hospitalaria del 6% para la cirugía electiva. Cuatro cardiopatías congénitas en el adulto se corrigieron sin mortalidad hospitalaria. La cirugía cardíaca con circulación extracorpórea es posible de ser realizada con buenos resultados con un hospital de las caracteristicas anotadas
Assuntos
Adulto , Pessoa de Meia-Idade , Humanos , Masculino , Feminino , Circulação Extracorpórea , Cirurgia Torácica , ArgentinaRESUMO
Se presenta la experiencia inicial en cirugía cardíaca a corazón abierto de un hospital general de 150 camas alejado de un centro universitario. Entre noviembre de 1982 y julio de 1984 fueron operados con circulación extracorpórea 93 pacientes: los 53 coronarios (61,0 años de promedio, 17% mujeres) incluyeron 5 lesiones de tronco y recibieron un promedio de 2,8 puentes por paciente, durante un "clampeo" aórtico promedio de 21 minutos por puente. La protección miocárdica estuvo asegurada por hipotermia general moderada, cardioplejía hipercalémica fría e irrigación continua del pericardio con suero frío. La mortalidad hospitalaria fue del 1,9%. Los 35 valvulares (56,6 años de promedio, 50% mujeres) repartidos en 5 comisurotomías mitrales, 6 reemplazos mitrales aislados, 16 reemplazos aórticos aislados, 4 reemplazos aórticos más puente y 4 dobles reemplazos, recibieron bajo una protección miocárdica similar 19 prótesis mecánicas y 14 biológicas, con una mortalidad hospitalaria del 6% para la cirugía electiva. Cuatro cardiopatías congénitas en el adulto se corrigieron sin mortalidad hospitalaria. La cirugía cardíaca con circulación extracorpórea es posible de ser realizada con buenos resultados con un hospital de las caracteristicas anotadas (AU)