History of Richmond as a port city

The purpose of this study has been to trace the evolution and course of Richmond as a port city from its beginning date, its period of gradual growth, the years of peak activity in the nineteenth century, the beginning of its decline in world trade, the subsequent renaissance of the port, followed by a recent decline at the present time, pointing out factors which brought it about and contributed to each of these stages

Thermal Stability of Sol-Gel Derived 6 Mole%CaO-ZrO₂ Ceramics

The thermal behavior of the hyperfine interaction at Zr sites on two sol-gel derived 6 mole% CaO-ZrO₂ powders, obtained from the particulate and non-particulate regimes, has been studied by Perturbed Angular Correlations and complementary techniques. The aim was to get experimental support on the thermal stability of the obtained material in order to see the advantages of the different preparation regimes. The results could be interpreted in terms of the different microstructures and nanoscopic configurations exhibited by the resulting powders. After crystallization both powders showed the hyperfine nanoconfigurations of metastable tetragonal zirconia. In the sample obtained following the hydrolysis and the condensation processes via a particulate regime, the undesirable phase transformation towards the monoclinic form of zirconia is inhibited up to higher temperatures.Instituto de Física La Plat

Thermal Stability of Sol-Gel Derived 6 Mole%CaO-ZrO₂ Ceramics

The thermal behavior of the hyperfine interaction at Zr sites on two sol-gel derived 6 mole% CaO-ZrO₂ powders, obtained from the particulate and non-particulate regimes, has been studied by Perturbed Angular Correlations and complementary techniques. The aim was to get experimental support on the thermal stability of the obtained material in order to see the advantages of the different preparation regimes. The results could be interpreted in terms of the different microstructures and nanoscopic configurations exhibited by the resulting powders. After crystallization both powders showed the hyperfine nanoconfigurations of metastable tetragonal zirconia. In the sample obtained following the hydrolysis and the condensation processes via a particulate regime, the undesirable phase transformation towards the monoclinic form of zirconia is inhibited up to higher temperatures.Instituto de Física La Plat

Role of age and comorbidities in mortality of patients with infective endocarditis

[Purpose]: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality. [Methods]: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015.Patients were stratified into three age groups:<65 years,65 to 80 years,and ≥ 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk. [Results]: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 ≥ 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients ≥80 years who underwent surgery were significantly lower compared with other age groups (14.3%,65 years; 20.5%,65-79 years; 31.3%,≥80 years). In-hospital mortality was lower in the <65-year group (20.3%,<65 years;30.1%,65-79 years;34.7%,≥80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%,≥80 years; p = 0.003).Independent predictors of mortality were age ≥ 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI ≥ 3 (HR:1.62; 95% CI:1.39–1.88),and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared,the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality. [Conclusion]: There were no differences in the clinical presentation of IE between the groups. Age ≥ 80 years, high comorbidity (measured by CCI),and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group