Search

Answer questions and earn CME/CNE. To update the melanoma staging system of the American Joint Committee on Cancer (AJCC) a large database was assembled comprising >46,000 patients from 10 centers worldwide with stages I, II, and III melanoma diagnosed since 1998. Based on analyses of this new database, the existing seventh edition AJCC stage IV database, and contemporary clinical trial data, the AJCC Melanoma Expert Panel introduced several important changes to the Tumor, Nodes, Metastasis (TNM) classification and stage grouping criteria. Key changes in the eighth edition AJCC Cancer Staging Manual include: 1) tumor thickness measurements to be recorded to the nearest 0.1 mm, not 0.01 mm; 2) definitions of T1a and T1b are revised (T1a

The sequential extraction (SEP) of selenium to determine the isotopic composition of different Se pools in soils is an important tool for tracking biogeochemical cycling of Se in soils. An appropriate Se extraction method for the stable Se isotope analysis was established and tested for different Se pools in soils in terms of reproducibility and recovery. Soil samples (n = 4) from a seleniferous field site in Punjab, India and two standard reference materials were chosen because of their relatively high total Se concentration of 2 to 4.5 mg kg− 1. Additionally, a soil sample with low Se content was utilized to verify the procedure and reproducibility. The isotopic mass-balance calculation gives consistent δ82Se values for the sum of the extracted pools, relative to δ82Se of the bulk soils. For instance, in one studied soil (soil-1), the sum of δ82Se of all individual Se-pools (δ82Semass-balance = 3.35‰) is in good agreement with the analysis of δ82Se of the bulk soil (δ82Sebulk of 3.56‰). We observed up to a 2‰ range in δ82Se among the different Se soil-pools (soil-3). Our Se isotopic results of Se soil pools provide more detailed observations of the Se linked processes in soils compared to bulk δ82Se. Thus, quantitative Se isotopic analysis of different Se pools can be an important tool for predicting the environmental cycling of selenium in soils or sediments.

International audience; Introduction: The impact of human activities such as industries, agriculture and domestic inputs, becomes more and more significant on the chemical composition (major ions and pollutants including metals) of the dissolved load of rivers in addition with natural inputs. Furthermore, this influence can also be evidenced in the suspended solid matter known to play a major role in the transport of heavy metals through river systems. Human factors act as an additional key process. Therefore the mass-balance for the budget of catchments and river basins includes anthropogenic disturbances. Here we are reporting concentration and isotope data for heavy metals zinc (Zn), cadmium (Cd), lead (Pb) and mercury (Hg) in river waters and suspended sediments from the Loire River Basin. In addition, we also report concentration and isotope data for these metals for the different anthropogenic sources within the Loire Basin, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany, these organisms are known to be natural accumulators of metal pollutants. Results: The Loire River in Central France is approximately 1010 km long and drains an area of 117 800 km2. Upstream, the Loire River flows south to north from the Massif Central down to the city of Orléans, 650 km from its source. The Loire River is one of the main European riverine inputs to the Atlantic Ocean. Over time, its basin has been exposed to numerous sources of anthropogenic metal pollutions, such as metal mining, food industry, agriculture and domestic inputs. The Loire River basin is thus an excellent study site to develop new isotope systematics for tracking anthropogenic sources of metal pollutions. We have chosen to analyse the isotope composition of Cd, Zn, Hg and Pb. These heavy metals have been selected for their toxicity, even at low levels, to humans. The main goal of this study is to characterize 1) the sources and behaviour of these heavy metals in the aquatic environment, and 2) their spatial distribution using a multi-isotope approach. Sources responsible for the release of Pb-Zn-Cd-Hg in the Loire basin were sampled and analysed for their concentrations and corresponding isotope compositions. We also analysed river waters, suspended solids samples and biota samples (mussels, oysters). All trace elements were analysed in the BRGM laboratories using a Q-ICPMS. Pb-Zn-Cd isotope compositions were measured using a Neptune MC-ICPMS at the BRGM. Hg isotope compositions were measured at the University of Illinois using a Nu Plasma MC-ICPMS. To analyse Zn and Cd, we carried out a two-steps analytical development: 1) a chromatographic separation, followed by 2) analysis on the MC-ICPMS. Each of these isotope systematics on their own reveals important information about their geogenic or anthropogenic origin but, considered together, provide a more integrated understanding of the budgets of these pollutants within the Loire River Basin. Acknowledgments: We would like to thank the IFREMER (French Oceanographic Institute) for providing biota samples and we also cordially thank AMP (Analyses Mesures Pollution) for their help during the sample collection of suspended sediments.

Projet ISOP; International audience; The contribution of human activities such as industries, agriculture and domestic inputs, becomes more and more significant in the chemical composition (major ions and pollutants such as metals) of the dissolved load of rivers. Furthermore, this influence can also be evidenced in the suspended solid matter known to play an important role in the transport of heavy metals through river systems. Human factors act as a supplementary key process. Therefore the mass-balance for the budget of catchments and river basins include anthropogenic disturbances. The Loire River in central France is approximately 1010 km long and drains an area of 117,800 km2. Initially, the Loire upstream flows in a south to north direction originating in the Massif Central, and continues up to the city of Orléans, 650 km from the source. In the upper basin, the bedrock is old plutonic rock overlain by much younger volcanic rocks. The Loire River then follows a general east to west direction to the Atlantic Ocean. The intermediate basin includes three major tributaries flowing into the Loire River from the left bank: the Cher, the Indre and the Vienne rivers; the main stream flows westward and its valley stretches toward the Atlantic Ocean. Here, the Loire River drains the sedimentary series of the Paris Basin, mainly carbonate deposits. The lower Loire basin drains pre-Mesozoic basement of the Armorican Massif and its overlying Mesozoic to Cenozoic sedimentary deposits. The Loire River is one of the main European riverine inputs to the Atlantic ocean. Here we are reporting concentration and isotope data for heavy metals Zn-Cd-Pb-Hg in river waters and suspended sediments from the Loire River Basin. In addition, we also report concentration and isotope data for these metals for the different industrial sources within the Loire Basin, as well as data for biota samples such as mussels and oysters from the Bay of Biscay and North Brittany. These organisms are known to be natural accumulators of metal pollutants. The main objective of this study is to characterize the sources and the behavior of these heavy metals in the aquatic environment, and their spatial distribution using a multi-isotope approach. Each of these isotope systematics on their own reveals important information about their geogenic or anthropogenic origin but, considered together, provide a more integrated understanding of the budgets of these pollutants within the Loire River Basin.

The sequential extraction (SEP) of selenium to determine the isotopic composition of different Se pools in soils is an important tool for tracking biogeochemical cycling of Se in soils. An appropriate Se extraction method for the stable Se isotope analysis was established and tested for different Se pools in soils in terms of reproducibility and recovery. Soil samples (n = 4) from a seleniferous field site in Punjab, India and two standard reference materials were chosen because of their relatively high total Se concentration of 2 to 4.5 mg kg− 1. Additionally, a soil sample with low Se content was utilized to verify the procedure and reproducibility. The isotopic mass-balance calculation gives consistent δ82Se values for the sum of the extracted pools, relative to δ82Se of the bulk soils. For instance, in one studied soil (soil-1), the sum of δ82Se of all individual Se-pools (δ82Semass-balance = 3.35‰) is in good agreement with the analysis of δ82Se of the bulk soil (δ82Sebulk of 3.56‰). We observed up to a 2‰ range in δ82Se among the different Se soil-pools (soil-3). Our Se isotopic results of Se soil pools provide more detailed observations of the Se linked processes in soils compared to bulk δ82Se. Thus, quantitative Se isotopic analysis of different Se pools can be an important tool for predicting the environmental cycling of selenium in soils or sediments.

The natural abundance of stable Se isotopes in methylselenides reflects sources and formation conditions of methylselenides. We tested the effects of (i) different inorganic Se species spiked to soils and (ii) different soil samples on the extent of fungal biomethylation of Se and the Se isotope ratios (δ82/76Se) in methylselenides. Furthermore, we assessed the decrease of dissolved, bioavailable Se during three days of equilibration of the soils with Se-enriched solutions. We conducted closed microcosm experiments containing soil spiked with Se(IV) or Se(VI), a growth medium, and the fungus species Alternaria alternata for 11 d. The concentrations and isotope ratios of Se were determined in all components of the microcosm with multicollector ICP-MS. The equilibration of the spiked Se(IV) and Se(VI) for 3 d resulted in a decrease of dissolved, bioavailable Se concentrations by 32 to 44% and 8 to 14%, respectively. Very little isotope fractionation occurred during this phase, and it can be attributed to mixing of the added Se with the pre-existing Se in the soils and minor Se(IV) reduction in one experiment. In two of the incubated soils – moderately acidic roadside and garden soils – between 9.1 and 30% of the supplied Se(IV) and 1.7% of the supplied Se(VI) were methylated while in a strongly acidic forest soil no Se methylation occurred. The methylselenides derived from Se(IV) were strongly depleted in 82Se (δ82/76Se = − 3.3 to − 4.5‰) compared with the soil (0.16–0.45‰) and the added Se(IV) (0.20‰). The methylselenide yield of the incubations with Se(VI) was too small for isotope measurements. Our results demonstrate that Se source species and soil properties influence the extent of Se biomethylation and that the produced methylselenides contain isotopically light Se.