0000000000327563
AUTHOR
Barros H
Cationi metallici incorporati nei carbonati primari e pedogenici.
Diversi cationi metallici, tra cui alcuni traccianti diagenetici e importanti contaminanti ambientali possono sostituire il calcio nella struttura della calcite o co-precipitare con essa. Scopo di questo lavoro è stato di investigare quali cationi metallici sono associati ai carbonati del suolo e di quantificarli. A tal fine, sono stati scelti cinque pedon evolventi su diversi litotipi e con un contenuto in carbonati piuttosto variabile. I campioni di suolo sono stati trattati con acido acetico 1M per permettere la dissoluzione selettiva dei carbonati e le soluzioni risultanti sono state analizzate per i seguenti cationi metallici: Ca, Cr, Mn, Fe, Co, Ni, Sr, Ba, Pb, U. Dai risultati si evi…
National, regional, and global trends in serum total cholesterol since 1980: systematic analysis of health examination surveys and epidemiological studies with 321 country-years and 3·0 million participants
Summary Background Data for trends in serum cholesterol are needed to understand the effects of its dietary, lifestyle, and pharmacological determinants; set intervention priorities; and evaluate national programmes. Previous analyses of trends in serum cholesterol were limited to a few countries, with no consistent and comparable global analysis. We estimated worldwide trends in population mean serum total cholesterol. Methods We estimated trends and their uncertainties in mean serum total cholesterol for adults 25 years and older in 199 countries and territories. We obtained data from published and unpublished health examination surveys and epidemiological studies (321 country-years and 3…
Application of ICP-MS for measuring soil metal cations from sequential extraction
The present work is part of a collaboration between Palermo and Seville Universities to investigate the cations incorporated into calcite and its effect in the trace metal mobility in soils. The study area is located in the central part of Sicily. Calcite is usually greatly dispersed and has a major influence on the pH of soils and therefore on trace element behaviour. A great affinity for carbonates has been observed for a wide range of cations incorporated into calcite. in order to investigate the metal cations in soil carbonate, 1M MgCl2 was used to remove the exchangeable Ca. Sub-samples were treated with acid acetic 1M to quantify the total amount of Ca and metal cations in soil carbon…