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Synthesis and evaluation of novel radioiodinated nicotinamides for malignant melanoma
No full textIntroduction
A series of iodonicotinamides based on the melanin-binding iodobenzamide compound N-2-diethylaminoethyl-4-iodobenzamide was prepared and evaluated for the potential imaging and staging of disseminated metastatic melanoma.
Methods
[123I]Iodonicotinamides were prepared by iododestannylation reactions using no-carrier-added iodine-123 and evaluated in vivo by biodistribution and competition studies and by single photon emission computed tomography (SPECT) imaging in black and albino nude mice bearing B16F0 murine melanotic and A375 human amelanotic melanoma tumours, respectively.
Results
The iodonicotinamides displayed low-affinity binding for σ1–σ2 receptors (Ki>300 nM). In biodistribution studies in mice, N-(2-(diethylamino)ethyl)-5-[123I]iodonicotinamide ([123I]1) exhibited the fastest and highest uptake of the nicotinamide series in the B16F0 tumour at 1 h (∼8% ID/g), decreasing slowly over time. No uptake was observed in the A375 tumour. Clearance from the animals by urinary excretion was more rapid for N-alkyl-nicotinamides than for piperazinyl derivatives. At 1 h postinjection, the urinary excretion was 66% ID for [123I]1, while the gastrointestinal tract amounted to 17% ID. Haloperidol was unable to reduce the uptake of [123I]1 in pigmented mice, indicating that this uptake was likely due to an interaction with melanin. SPECT imaging of [123I]1 in black mice bearing the B16F0 melanoma indicated that the radioactivity was predominately located in the tumour and eyes. No specific localisation was observed in nude mice bearing A375 amelanotic tumours.
Conclusion
These findings suggest that [123I]1, which displays high tumour uptake with rapid clearance from the body, could be a promising imaging agent for the detection of melanotic tumours. © 2008 Elsevier Inc
New chronology for the southern kalahari group sediments: implications for sediment cycle dynamics and early hominin occupation
No full textThe Kalahari Group covers an extensive part of the southern African continent and forms a low-relief landscape dominated by extensive unconsolidated sand. Current depositional models assume that the Kalahari Group sediments accumulated gradually throughout the Cenozoic, but an absence of absolute chronology beyond ~60 ka has left this premise untested. Here, we challenge this age model with new cosmogenic burial ages obtained from a 55 m section of Kalahari Group sediments at Mamatwan Mine near the southern edge of the Kalahari basin. Our results indicate that the majority of the existing section was emplaced rapidly at ~1 Ma. At this time the basin filled to its present level and established the Kalahari sand belts, which fostered the modern savannah. Our data suggest a dynamic landscape, with punctuated cycles of erosion and deposition, in contrast to the accepted concept of a stable basin filling slowly throughout the Cenozoic.
The sedimentology and cosmogenic nuclide measurements from the lower Mamatwan Mine section reveal the existence of an extensive Early to Middle Pleistocene water body, persisting at least 420 ka prior to the rapid filling event at ~1 Ma. This water body is contemporaneous with a significant hominin occupation as evidenced by neighboring archaeological excavations. We thus provide the first evidence of association of the high-density hominin occupation in southern Africa with an extensive water body
The value of a Pacific-wide tsunami database to risk reduction - putting theory into practice
No full textThe recent 2011 Tōhoku Tsunami showed yet again the devastating impact that these events can have on coastal communities. Even prior to the 2004 Indian Ocean Tsunami there had been a growing awareness of the need to document a record of past tsunamis for risk reduction purposes. The bulk of such early databases were based on historical data. Only in recent years have palaeotsunami databases started to be collated. When one considers that the Pacific region accounts for 85% of known historical tsunamis worldwide, it is unsettling that we have only documented 11 palaeotsunamis throughout all Pacific Island countries (PICs). The way forward to enhance our understanding of palaeotsunamis, and to better understand the magnitude and frequency of events from local, regional and distant Pacific sources, is to gather data from each PIC. By collating data from each island it should be possible to map the spatial and temporal distribution of past events over the last several thousand years throughout the entire Pacific region. These data will provide the essential baseline information needed for achieving more effective disaster risk reduction for PICs. © The Geological Society of London 2012
Using radon-222 to distinguish between vertical transport processes at Jungfraujoch
Full text linkTrace gases measured at Jungfrajoch, a key baseline monitoring station in the Swiss Alps, are tranported
from the surface to the alpine ridge by several different processes. On clear days with weak synoptic forcing,
thermally-driven upslope mountain winds (anabatic winds) are prevalent.
Using hourly radon–222 observations, which are often used to identify air of terrestrial origin, we used the
shape of the diurnal cycle to sort days according to the strength of anabatic winds. Radon is ideal as an airmass
tracer because it is emitted from soil at a relatively constant rate, it is chemically inert, and decays with a half-life
of 3.8 days. Because of its short half-life, radon concentrations are much lower in the free troposphere than in
boundary-layer air over land.
For comparable radon concentrations, anabatic wind days at Jungfraujoch are different from non-anabatic
days in terms of the average wind speed, humidity, air temperature anomalies, and trace species. As a consequence, future studies could be devised which focus on a subset of days, e.g. by excluding anabatic days, with the
intention of choosing a set of days which can be more accurately simulated by a transport model. © Author(s) 2014
Kinetics of coupled Fe(II)-catalysed ferrihydrite transformation and U(VI) reduction
Full text linkAntimony is released into the environment in some natural and man-induced processes. [1]. Yet, its impact on the transformation processes of heavy metal-adsorbing minerals
remains poorly understood. In acid-mine drainage systems and shooting ranges, the adsorption of antimony by iron oxides
such as ferrihydrite can play a major role. The poorly crystalline 2-line ferrihydrite represents one of the most common Fe oxides in these settings and can transform to
goethite (,-FeOOH) or hematite (,-Fe2O3) with time [2]. The
rate of transformation depends on the pH, temperature, and on
the ions and molecules present during the transformation
process [3]. This study focuses on the transformation of
synthetic ferrihydrite to crystalline iron oxides in the presence
of Sb(V). Transformations were carried out for 1-16 days at 70
ºC and at pH 4, 7 and 12, with different concentrations of
Sb(V) (0.00, 0.23, 0.75, 2.25 and 6.00 mM Sb). Samples taken
from aqueous suspensions were washed, dried, and
characterized by X-ray diffraction (XRD) and atomic
absorption spectroscopy (AAS). At pH 12, goethite (Sb
concentrations up to 3.7 mg Sb/g) is favored and the
transformation is completed after one day. Only a
concentration of 6 mM Sb retarded the transformation, where
even after 8 days only 50 % of the ferrihydrite was
transformed into goethite. Transformations at pH 7 led to a
mixture of 75 % hematite and 25 % goethite (4.3 mg Sb/g).
However, at concentrations of 6 mM Sb, feroxyhyte (!-
FeOOH) (9.1 mg Sb/g) was favored instead. At pH 4, hematite
(32.3 mg Sb/g) was favored except for concentrations of 6
mM Sb, were again feroxyhyte (141.1 mg Sb/g) occurred. We assume that increased Sb concentrations favor feroxyhyte and indicate the incorporation of Sb into the structure of
feroxyhyte. © The Author
Applications and impact of radiotracers and nucleonic measurement systems for investigation of sediment transport
No full textNot available
Lower Hunter particle characterisation study Final Report to the NSW Environment Protection Authority
No full textThe Lower Hunter Particle Characterisation Study (LHPCS) provides details about the composition and major sources of PM2.5 (fine airborne particles)and PM2.5-10(coarse airborne particles).
Measurements were made for one year from March 2014 to February 2015 at two air quality monitoring stations representative of regional population exposures (Newcastle and Beresfield) and two stations near the Port of Newcastle (Mayfield and Stockton).
Annual average PM2.5 concentrations were very similar at Newcastle, Mayfield and Beresfield (6.4–6.7 μg m-3) but about 40% higher at Stockton (9.1 μg m-3). The higher levels at Stockton were mainly due to both more sea salt and to the primary ammonium nitrate, which was only detected at Stockton. The ammonium nitrate, which contributed on average 19% of the PM2.5 mass (and ~40% in winter), was identified as very likely to be due to primary emissions from Orica’s ammonium nitrate manufacturing facility on Kooragang Island.
Other than the ammonium nitrate, PM2.5 composition and sources were found to be fairly similar across the four sites. Key results on the sources and their contributions are: fresh sea salt particles: 24% at Newcastle, decreasing to 13% at Beresfield; pollutant-aged sea salt: ~23% at all sites; this is sea salt reacted with industrial, commercial, road and non-road transport emissions from local and regional sources; wood smoke: 15% at Beresfield, decreasing to 6% at Stockton; secondary ammonium sulfate: ~10% at all sites; soil dust: ~10% at all sites; vehicles: ~10% at three sites, but only 5% at Stockton; industry factors: ~12% at three sites but 24% at Stockton; mixed shipping/industry: ~3% at all sites; nitrate: 19% ammonium nitrate at Stockton and secondary nitrate at other sites (6-11%).
On an annual average basis, there is an approximately 50:50 split between primary and secondary particles at three sites (Newcastle, Beresfield and Mayfield) and a 65:35 split at Stockton because of the significant contribution from the primary ammonium nitrate.
PM2.5-10 composition and sources were only determined at the stations near the Port of Newcastle. The 2½ times higher annual average PM2.5-10 concentration at Stockton (21.5 μg m-3) than at Mayfield (8.3 μg m-3) was found to be mainly due to a much higher contribution by fresh sea salt particles at Stockton.
The PM2.5-10 factors and their contributions were identified as:
fresh sea salt: 13.6 μg m-3 at Stockton, 3.3 μg m-3 at Mayfield
industry plus pollutant-aged sea salt: 2.4 μg m-3 at both sites
light-absorbing carbon: 2.2 μg m-3 at Stockton, 0.9 μg m-3 at Mayfield
soil: 2.3 μg m-3 at Stockton, 1.2 μg m-3 at Mayfield
bioaerosol: 1.1 μg m-3 at Stockton, 0.5 μg m-3 at Mayfield.
Most PM2.5-10 particles are primary particles or physical combinations of primary emissions, but there is evidence of chemical reactions in the pollutant-aged sea salt factor.
Coal particles could contribute up to 10% of PM2.5-10 particles. Further investigations are needed to clarify the contribution of coal
A quasi-monthly record of 10Be concentration at Law Dome, Antarctica, from 2000 to 2015
No full textThis paper presents an overview of work undertaken over a number of Australian Antarctic
Science projects, beginning in season 2001/02 with a shallow snow pit. In season 2005/06
this was augmented with a 260 m thermally drilled ice core and a 4.5 m snow pit. A core
taken in 2008/09 overlapped the 2005/06 core and pit samples. From 2009/10, short cores
spanning a few year’s deposition, along with snow pit samples spanning about half a year,
have been taken each season. This has continued through to the current 2015/16 season.
The cores permit an overlap with earlier years to match the chronology and to yield samples
for 10Be analysis at the Australian Nuclear Science and Technology Organisation (ANSTO) by
the technique of accelerator mass spectrometry (AMS). Together, the data provide a unique,
continuous, quasi-monthly record over 2000 to 2015 as we have moved from Solar Cycle 23
to 24. The snow pits yield larger samples for 7Be analysis, earlier by gamma spectroscopy
but lately by AMS. Along with comparison with neutron monitor data and GCM modelling,
this unique, high-precision record has enabled us to learn much about the production,
transport and deposition of 10Be to Law Dome and to improve our use of 10Be as a proxy for
past solar variability
Using magnetic fabric to reconstruct the dynamics of tsunami deposition on the Sendai Plain, Japan — The 2011 Tohoku-oki tsunami
No full textThe magnetic fabric and grain size of sand deposits emplaced during the 2011 Tohoku-oki tsunami were studied in five trenches along a 1800 m long shore normal transect on the Sendai plain as well as in a near shore sedimentary infill of a scour depression. The magnetic susceptibility in all deposits is due to ferromagnetic minerals (mainly magnetite) making the anisotropy of magnetic susceptibility (magnetic fabric) suitable for fabric analyses. The dominant magnetic fabric is planar in all trenches and stronger in finer-grained inland deposits than in the coarser sediments. This planar fabric is related to tractive shearing of the bedload basal portion of the tsunami flow that led to the deposition of traction carpet layers. Among the various fabric parameters used for this study, the vertical evolution of the shape factor (q) of the magnetic ellipsoid in each trench follows the evolution of the magnetic lineation (L) and foliation (F). These parameters provide information on the hydrodynamic energy (flow speed) fluctuations during the emplacement of the tsunami deposit. For the most proximal deposits, characterized by well-sorted reworked beach sand with minor fluctuations in grain-size distribution, the magnetic fabric is sensitive to hydrodynamic energy variations during sedimentation. Reconstruction of tsunami flow orientation in the sediments, based on the orientation of the mean Kmax calculated for each trench, appears to be unambiguous only for the sandy infills of small topographic depressions. The variations in flow direction indicators elsewhere could be related to local variation of the flow and to micro-topographic effects. These findings are encouraging for the use of the magnetic fabric proxy in the study of paleotsunami deposits. © 2014 Elsevier B.V
Using advaced weld modelling to ensure the structural integrity of plant in the nuclear industry
No full textNot available. Physical copy available in ANSTO Library at 621.48/17Using advaced weld modelling to ensure the structural integrity of plant in the nuclear industr