975 resultados para cobalt 60
Resumo:
A 39-year-old female with elevated serum cobalt levels from her bilateral hip prostheses presented with a 3-week history of blurred vision in her left eye. Optical coherence tomography revealed patchy degeneration of the photoreceptor-retinal pigment epithelium (RPE) complex. The lesions were hypofluorescent on indocyanine green angiography. We postulate that this is a case of implant-related chorio-retinal cobalt toxicity.
Resumo:
Hyperkalemia is a concern in heart failure (HF), especially in older patients with co-morbidities. Previous studies addressing this issue have focused mainly on younger patients. This study was aimed at determining the frequency and predictors of hyperkalemia in older patients with HF undergoing intense medical therapy. Frequency and predictors of hyperkalemia were defined in patients (n = 566) participating in the Trial of Intensified versus Standard Medical Therapy in Elderly Patients with Congestive Heart Failure, in which patients ≥60 years of age were randomized to a standard versus an intensified N-terminal brain natriuretic peptide-guided HF therapy. During an 18-month follow-up 76 patients (13.4%) had hyperkalemia (≥5.5 mmol/L) and 28 (4.9%) had severe hyperkalemia (≥6.0 mmol/L). Higher baseline serum potassium (odds ratio [OR] 2.92 per mmol/L), baseline creatinine (OR 1.11 per 10 μmol/L), gout (OR 2.56), New York Heart Association (NYHA) class (compared to NYHA class II, IV OR 3.08), higher dosage of spironolactone at baseline (OR 1.20 per 12.5 mg/day), and higher dose changes of spironolactone (compared to no dose change: 12.5 mg, OR 1.45; 25 mg, OR 2.52; >25 mg, OR 3.24) were independent predictors for development of hyperkalemia (p <0.05 for all comparisons). In conclusion, hyperkalemia is common in patients ≥60 years of age with HF undergoing intense medical therapy. Risk is increased in patients treated with spironolactone, in addition to patient-specific risk factors such as chronic kidney disease, higher serum potassium, advanced NYHA class, and gout. Careful surveillance of serum potassium and cautious use of spironolactone in patients at risk may help to decrease the incidence of potentially hazardous complications caused by hyperkalemia.
Resumo:
The present study was undertaken to assess the influence of childhood variables (physical and emotional) to later well-being in a group of rural Swiss (Emmental Cohort). Our study is the first prospective cohort over a time period of more than 50 years. It includes 1537 children who were listed and assessed in 1942 (T1) because they had difficulties in school or were otherwise behaviorally disturbed. In 1995 (T2) more than 60% of the initial population could be reassessed by our study group. We found more subjects at T2 who had been rated as intelligent at T1. More subjects responding to T2 belonged to a higher social class, were more anxious, and had more psychosocial problems at T1. Social income at T2 is correlated to the social class at T1. More subjects have died since who were rated at T1 as being less intelligent, less neurotical, and having higher psychosocial problems. Twice as many men died than women. The emotional situation at T2 is significantly correlated to psychological well-being at T1. The somatic complaints at T2 correlate significantly to neurotic symptoms in childhood (T1). The more intelligent the children were rated at T1, the less emotional and somatic complaints were voiced at T2 and the better the psychic well-being was rated (T2). In addition, the former social milieu (T1) significantly determined somatic and psychological complaints at T2. Our data discern a significant correlation between actual status and former childhood variables more than 50 years later in a rural Swiss cohort (Emmental Cohort).
Resumo:
Global warming issue becomes more significant to human beings and other organisms on the earth. Among many greenhouse gases, carbon dioxide (CO2) has the largest contribution to global warming. To find an effective way to utilize the greenhouse gas is urgent. It is the best way to convert CO2 to useful compounds. CO2 reforming of methane is an attractive process to convert CO2 and methane into synthesis gas (CO/H2), which can be used as a feedstock for gasoline, methanol, and other hydrocarbons. Nickel and cobalt were found to have good activity for CO2 reforming. However, they have a poor stability due to carbon deposition. This research developed efficient Ni-Co solid solution catalysts with excellent activities and high stability for CO2 reforming of methane. First, the structure of binary oxide solid solution of nickel and cobalt was investigated. It was found that while the calcination of Ni(NO3)2 and Co(NO3)2 mixture with 1:1 molar ratio at a high temperature above 800 oC generated NiO-CoO solid solution, only Ni3O4-Co3O4 solid solution was observed after the calcination at a low temperature of 500 oC. Furthermore, if the calcination was carried out at a medium temperature arranged from 600 to 700 oC, both NiO-CoO and Ni3O4-Co3O4 solid solutions can be formed. This occurred because Co3O4 can induce the formation of Ni3O4, whereas NiO can stabilize CoO. In addition, the lattice parameter of Ni3O4, which was predicted by using Vegard’s Law, is 8.2054 Å. As a very important part of this dissertation, Ni-Co solid solution was evaluated as catalysts for CO2 reforming of methane. It was revealed that nickel-cobalt solid solution showed excellent catalytic performance and high stability for CO2 reforming of methane. However, the stability of Ni-Co solid solution catalysts is strongly dependent on their composition and preparation condition. The optimum composition is 50%Ni-50%Co. Furthermore, the structure of Ni-Co catalysts was characterized by XRD, Vvis, TPR, TPD, BET, AES, TEM, XANES and EXAFS. The relationship between the structure and the catalytic performance was established: (1) The reduced NiO-CoO solid solution possesses better catalytic performance and stability than the reduced Ni3O4-Co3O4 solid solution. (2) Ni is richer on surface in Ni-Co catalysts. And (3) the reduction of Ni-Co-O solid solution generated two types of particles, small and large particles. The small ones are dispersed on large ones as catalytic component.