4 research outputs found
sj-vid-2-arr-10.1177 2058460118778068 -Supplemental material for Variable size of aortic subvalvular pseudoaneurysm
<p>Supplemental material, sj-vid-2-arr-10.1177 2058460118778068 for Variable size of aortic subvalvular pseudoaneurysm by Anders Svensson, Kerstin Cederlund, Torkel B Brismar and Raquel Themudo in Acta Radiologica Open</p
sj-vid-1-arr-10.1177 2058460118778068 -Supplemental material for Variable size of aortic subvalvular pseudoaneurysm
<p>Supplemental material, sj-vid-1-arr-10.1177 2058460118778068 for Variable size of aortic subvalvular pseudoaneurysm by Anders Svensson, Kerstin Cederlund, Torkel B Brismar and Raquel Themudo in Acta Radiologica Open</p
Continuous Flow Analysis Method for Determination of Dissolved Reactive Phosphorus in Ice Cores
Phosphorus (P) is an essential macronutrient
for all living organisms.
Phosphorus is often present in nature as the soluble phosphate ion
PO<sub>4</sub><sup>3–</sup> and has biological, terrestrial,
and marine emission sources. Thus PO<sub>4</sub><sup>3–</sup> detected in ice cores has the potential to be an important tracer
for biological activity in the past. In this study a continuous and
highly sensitive absorption method for detection of dissolved reactive
phosphorus (DRP) in ice cores has been developed using a molybdate
reagent and a 2-m liquid waveguide capillary cell (LWCC). DRP is the
soluble form of the nutrient phosphorus, which reacts with molybdate.
The method was optimized to meet the low concentrations of DRP in
Greenland ice, with a depth resolution of approximately 2 cm and an
analytical uncertainty of 1.1 nM (0.1 ppb) PO<sub>4</sub><sup>3–</sup>. The method has been applied to segments of a shallow firn core
from Northeast Greenland, indicating a mean concentration level of
2.74 nM (0.26 ppb) PO<sub>4</sub><sup>3–</sup> for the period
1930–2005 with a standard deviation of 1.37 nM (0.13 ppb) PO<sub>4</sub><sup>3–</sup> and values reaching as high as 10.52
nM (1 ppb) PO<sub>4</sub><sup>3–</sup>. Similar levels were
detected for the period 1771–1823. Based on impurity abundances,
dust and biogenic particles were found to be the most likely sources
of DRP deposited in Northeast Greenland
A Chinese Imprint in Insoluble Pollutants Recently Deposited in Central Greenland As Indicated by Lead Isotopes
A unique ∼10 year record of the lead isotopic composition
of airborne insoluble particulate matter deposited in central Greenland
was extracted from recent snow layers at NorthGRIP (75.1°N, 042.3°W;
elevation 2,959 m), spanning the years 1989–2001. Comparison
with lead isotopic signatures of both natural and anthropogenic northern
hemisphere (NH) aerosol sources shows that human activities must have
accounted for most of the insoluble lead deposited on Greenland during
the late 1990s, exceeding by far the natural contribution from large
Asian mineral dust inputs. Lead isotopes imply predominance with time
of European/Canadian sources over U.S.-derived lead, with an admixed
signature typical of Chinese anthropogenic lead sources. The relative
contribution of the latter shows a marked seasonal increase during
spring. Our record also suggests that China’s weight in the
overall supply of insoluble pollutants deposited on Greenland was
growing over the past decade of the 20th century