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- Species-specific time trends and enantiomer fractions of hexabromocyclododecane (HBCD) in biota from East Greenland. [Journal Article, Research Support, Non-U.S. Gov't]
- Environ Sci Technol 2012 Oct 2; 46(19):10549-55.
Time trends of hexabromocyclododecane (HBCD) isomers were studied for glaucous gull and ringed seal from East Greenland. The ringed seal results extended a previous time trend (1986-2008) to 2010. α-HBCD was the only isomer consistently above quantification limits. For glaucous gull liver, annual median values of α-HBCD (1994-2010) ranged from 22 to 120 ng/g lipid weight (lw) with no significant trend, while HBCD in ringed seal blubber from the same area showed a significant increase from 3.9 to 11 ng/g lw (1986-2010). Reasons for this difference are unknown, but might include different feeding habits and species-specific metabolisation processes. Concentrations of several organochlorine (OC) compounds were determined for glaucous gull and ringed seal samples collected from the same area in 2004. HBCD concentrations in glaucous gull liver appeared relatively low when compared to OC concentrations in the same tissue and to both HBCD and OCs in ringed seal blubber from the same area. Enantiomer fractions (EF) deviated significantly from racemic for all annual mean EFs in glaucous gull suggesting metabolisation processes toward an enrichment of (-)α-HBCD. For ringed seal, this enrichment was less pronounced and only significant for two of the ten years. For neither species, significant changes in EF were found over time.
- Characteristics and Comorbid Symptoms of Older Adults Reporting Death Ideation. [JOURNAL ARTICLE]
- Am J Geriatr Psychiatry 2012 Jun 13.
OBJECTIVE::To determine whether death ideation in late life is associated with markers of elevated risk for suicide, or reflects normal psychological processes in later life. DESIGN/
SETTING:: Population-based cross-sectional study in Gothenburg, Sweden.
PARTICIPANTS:: The sample consists of 345 men and women of age 85 years (born 1901-1902) and living in Gothenburg, Sweden.
MAIN OUTCOME MEASURES:: The Paykel Scale measured the most severe level of suicidality over an individual's lifetime. Other key measures were severity of depression and anxiety and frequency of death/suicidal ideation over the previous month.
RESULTS::Latent class analysis revealed distinct groups of older adults who reported recent death ideation. Recent death ideation did not occur apart from other risk factors for suicide; instead individuals reporting recent death ideation also reported either 1) recent high levels of depression and anxiety, or 2) more distant histories of serious suicidal ideation (indicative of worst point severity of suicidal ideation)-both of which elevate risk for eventual suicide.
CONCLUSIONS::Our results indicate a heterogeneous presentation of older adults who report death ideation, with some presenting with acute distress and suicidal thoughts, and others presenting with low distress but histories of serious suicidal ideation. The presence of death ideation is associated with markers of increased risk for suicide, including "worst point" active suicidal ideation.
- Polychlorinated biphenyls, organochlorine pesticides and polycyclic aromatic hydrocarbons in a one-off global survey of bivalves. [Journal Article, Research Support, Non-U.S. Gov't]
- J Environ Monit 2010 May; 12(5):1141-52.
During the Danish Galathea 3 expedition, bivalve samples were collected at the Faroe Islands, Greenland, Ghana, South Africa, Australia, Solomon Islands, New Zealand, Chile, US Virgin Islands, Boston, Newfoundland and Shetland Islands and analysed for organochlorines and PAHs. Concentration differences of up to three orders of magnitude were observed, with the highest concentrations at Boston harbour (SPCB 338 ng g(-1) dw, ΣSPAH 5966 ng g(-1) dw) and the Sydney estuary (ΣSPCB 282 ng g(-1) dw, SPAH 1453 ng g(-1) dw). Local impacts were also found for the Greenland capital Nuuk in terms of PCB and PAH levels, while other Greenland samples came closest to representing PAH background levels. Several locations had undetectable organochlorine levels, including Hobart and Chile, which had the lowest SPAH concentrations (<200 ng g(-1) dw). It was possible to group the stations according to their pyrogenic/petrogenic influence using Principal Component Analyses, and indications of petroleum sources were found at Nuuk.
- Explorations of new second-order nonlinear optical materials in the potassium vanadyl iodate system. [Journal Article]
- J Am Chem Soc 2011 Apr 13; 133(14):5561-72.
Four new potassium vanadyl iodates based on lone-pair-containing IO(3) and second-order Jahn-Teller distorted VO(5) or VO(6) asymmetric units, namely, α-KVO(2)(IO(3))(2)(H(2)O) (Pbca), β-KVO(2)(IO(3))(2)(H(2)O) (P2(1)2(1)2(1)), K(4)[(VO)(IO(3))(5)](2)(HIO(3))(H(2)O)(2)·H(2)O (P1), and K(VO)(2)O(2)(IO(3))(3) (Ima2) have been successfully synthesized by hydrothermal reactions. α-KVO(2)(IO(3))(2)(H(2)O) and β-KVO(2)(IO(3))(2)(H(2)O) exhibit two different types of 1D [VO(2)(IO(3))(2)](-) anionic chains. Neighboring VO(6) octahedra in the α-phase are corner-sharing into a 1D chain with the IO(3) groups attached on both sides of the chain in a uni- or bidentate bridging fashion, whereas those of VO(5) polyhedra in the β-phase are bridged by IO(3) groups into a right-handed helical chain with remaining IO(3) groups being grafted unidentately on both sides of the helical chain. The structure of K(4)[(VO)(IO(3))(5)](2)(HIO(3))(H(2)O)(2)·H(2)O contains novel isolated [(VO)(IO(3))(5)](2-) units composed of one VO(6) octahedron linked to five IO(3) groups and one terminal O(2-) anion. The structure of K(VO)(2)O(2)(IO(3))(3) exhibits a 1D [(VO)(2)O(2)(IO(3))(3)](-) chain in which neighboring VO(6) octahedra are interconnected by both oxo and bridging iodate anions. Most interestingly, three of four compounds are noncentrosymmetric (NCS), and K(VO)(2)O(2)(IO(3))(3) displays a very strong second-harmonic generation response of about 3.6 × KTP, which is phase matchable. It also has high thermal stability, a wide transparent region and moderate hardness as well as an excellent growth habit. Thermal analyses and optical and ferroelectric properties as well as theoretical calculations have also been performed.
- Temporal trends of hexabromocyclododecane, polybrominated diphenyl ethers and polychlorinated biphenyls in ringed seals from East greenland. [Journal Article, Research Support, Non-U.S. Gov't]
- Environ Sci Technol 2011 Feb 15; 45(4):1243-9.
Concentrations of hexabromocyclododecane (HBCD) were determined in a combination of archived and fresh blubber samples of juvenile ringed seals from East Greenland collected between 1986 and 2008. α-HBCD was the only diastereoisomer consistently above levels of quantification and showed a significant log-linear (exponential) increase from 2.0 to 8.7 ng/g lipid weight (median concentrations) with an annual rate of +6.1%. The concentrations were up to several orders of magnitude lower than those reported for marine mammals from industrialized areas. Previously presented time trends on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) have been extended with new data for 2006 and 2008. ΣPBDE in juvenile seals was the only parameter with a slight upward trend, however, dependent on the low 1986 concentration. Removing this data point resulted in a downward trend, which also was found for adult seals with a time trend starting in 1994. ΣPCB decreased significantly in juvenile seals, again due to the 1986 value, while no trend was found for the adult animals. This indicates stagnating PCB concentrations at a relatively high level, in some cases possibly exceeding tolerable daily intake rates for seal blubber as traditional Arctic food items.
- Polybrominated diphenyl ethers (PBDEs) in the indoor environment and associations with prenatal exposure. [Journal Article, Research Support, Non-U.S. Gov't]
- Environ Int 2011 Jan; 37(1):1-10.
As part of a larger exposure study, samples of dust and indoor air were collected in the homes of 43 pregnant women living in the Copenhagen area (Denmark) and analysed for 12 polybrominated diphenyl ethers using GC-MS. A second dust sample collected after delivery was analysed for BDE-183 and BDE-209, which were highly correlated with the pre-delivery samples, but did not reproduce the actual values. Concentrations as high as 80 μg/g were measured for the dominant BDE congener BDE-209, with median concentrations of 332 and 432 ng/g, respectively, in pre- and post-delivery dust samples. In 12% of the dust samples, the concentration of BDE-209 was lower than that of the summed concentration of PentaBDE congeners. The median concentrations of BDE-47 and BDE-99 in dust were 16.9 and 13.6 ng/g, respectively. The dust concentrations were in line with other European studies and confirmed previously established geographical differences between continental Europe and North America. Additional octa- and nonaBDE congeners (BDE-197, BDE-203, BDE-206, BDE-207, and BDE-208) were analysed in dust and analytical issues were discussed as these congeners also can be a product of thermal degradation of BDE-209 in gas chromatographic analysis. BDE-206 was the dominating nonaBDE, with median and maximum concentrations of 12.8 and 2217 ng/g, respectively, but the ratio of nonaBDEs to the sum of nona- and decaBDEs was relatively constant, despite a large range in absolute dust concentrations. While the congeners of the PentaBDE mixture were highly inter-correlated for both dust and air, no correlation was found with BDE-209 in either matrix. Air concentrations were relatively high in an international context, with median concentrations of 134, 63.7 and 119 pg/m³ for BDE-47, BDE-99 and BDE-209, respectively, and not correlated with dust concentrations. Additional placenta data were available for the study group and found to correlate significantly with dust concentrations for some PentaBDE congeners, but not BDE-209, indicating that dust may be an important exposure pathway for PentaBDE congeners. While BDE-209 also was present in placenta, it did not exceed the other congeners by the same factors as in dust. This might be caused by a combination of the compound's physical-chemical properties affecting bioavailability, uptake, partitioning and metabolisation, and other sources of exposure, but was not investigated further in this study. For all matrices, the PBDE profile resembled that of the technical product Bromkal 70-5DE, but air contained higher percentages of the lower brominated congeners and placenta tissue was dominated by BDE-153. The predominance of BDE-153 has been described in other studies on human samples and related to the highest retention in the body, but further research into toxicokinetics will be required to clarify mechanisms.
- Persistent organochlorine compounds in peregrine falcon (Falco peregrinus) eggs from South Greenland: levels and temporal changes between 1986 and 2003. [Journal Article, Research Support, Non-U.S. Gov't]
- Environ Int 2009 Feb; 35(2):336-41.
Thirty-seven addled peregrine falcon eggs collected in South Greenland between 1986 and 2003 were analysed for their content of the organochlorine compounds polychlorinated biphenyls (PCBs), dichlorodiphenyl tricloroethane (DDT) and its degradation products, hexachlorocyclohexane (HCH) isomers and hexachlorobenzene (HCB). PCBs and DDT (including metabolites) were by far the most abundant OC groups, with median concentrations of 55 and 40 microg/g lw, respectively. The concentrations were high in an Arctic context, but similar to previously reported levels from Alaska and Norway and slightly lower than concentrations measured in eggs from industrialised regions. Geographical differences may be of importance, considering the migration of peregrine falcons and their prey. SigmaHCH and HCB had median concentrations of 0.39 and 0.17 microg/g lw, respectively. On average, DDE accounted for 97% of SigmaDDT, but was below critical levels for eggshell thinning. All compound groups showed a weak decreasing trend over the study period, which was statistically significant for HCB and close to being significant for SigmaHCH. The weak decrease of SigmaPCB and SigmaDDT is different from other time trend studies from Greenland, usually showing a more pronounced decrease in the beginning of the study period, followed by a certain stabilisation in recent years.
- Insulin mimetic peroxo complexes of vanadium containing uracil or Cytosine as ligand. [Journal Article]
- Met Based Drugs 2000; 7(3):157-64.
Mixed ligand oxo peroxo complexes of vanadium (V), M[VO(O(2))L(2)].nH(2)O where M = K or NH(4), HL = uracil or cytosine and n = 1 or 2, have been isolated from aqueous methanolic medium. The complexes were characterised by elemental analysis, conductance, TGA, UV-Visible, IR and NMR spectral studies. Both the peroxide and the other ligands acts as chelates coordinating through their oxygen at C (2) and nitrogen at N (3) and the presence of monomeric oxoperoxovanadium (V) species, have been established by IR, (1)H and (51)V NMR studies. The complexes appeared to possess pentagonal bipyramidal geometry. The terminal oxo ligand and the oxygen of the uracil or cytosine at C (2) occupy the axial position while the peroxide and the other donor ligands are in the equatorial position. The UV spectral studies confirm the presence of Vanadium in its +5 oxidation state. The administration of the potassium salts of the complexes reduces the blood glucose level in Swiss Albino mice compared to that of KVO(3). The complexes also readily oxidise cysteine to Cystine in aqueous solution. The possible mechanism for the insulin-mimic activity of the complexes is discussed.
- Levels and trends of persistent organic pollutants in ringed seals (Phoca hispida) from Central West Greenland, with particular focus on polybrominated diphenyl ethers (PBDEs). [Journal Article, Research Support, Non-U.S. Gov't]
- Environ Int 2008 May; 34(4):499-508.
Polybrominated diphenyl ethers (PBDEs) and the organochlorine compounds polychlorinated biphenyls (PCBs), DDTs, HCB, chlordane-related pesticides, HCH and toxaphene were analysed in blubber of juvenile ringed seals from Central West Greenland collected between 1982 and 2006. The longest time series could be established for PBDEs, partly based on archived material, while PCBs and DDTs covered a study period from 1994-2006. All organochlorines showed decreasing trends, most pronounced for DDT and HCH with an annual change of 8%. BDE-47 had a significantly increasing trend of 5% annually. It was the only BDE congener consistently above the detection limit, with annual median concentrations between 0.78 ng/g lw to 3.54 ng/g lw, i.e. about 10 times lower than values from East Greenland observed in a similar time trend study on ringed seal blubber [Rigét F, Vorkamp K, Dietz R, Rastogi SC. Temporal trend studies on polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ringed seals from East Greenland. J Environ Monit 2006; 8: 1000-5]. A clear East>West difference was also found for PCBs and DDTs, but not for chlordanes, toxaphene or HCHs. Sigma 10-PCB, Sigma DDT and Sigma Chlordanes had similar annual median concentrations, typically exceeding SigmaPBDE by two orders of magnitude. The concentrations of HCH and toxaphene were in an intermediate group, with highest annual median concentrations of 135 ng/g lw and 20 ng/g lw, respectively. For most compound groups, the circumpolar trend previously established under for example the Arctic Monitoring and Assessment Programme was confirmed, but apparently, more data are needed for chlordane-related compounds and toxaphene. Statistical analyses of the compound patterns in the ringed seal samples revealed significantly greater differences between seals from East and West than between different sampling years. Higher proportions of PCBs and DDTs and lower proportions of chlordanes and HCHs were found in seals from East Greenland than in those from West Greenland. Based on principal component analysis of individual congener and compounds, seals from East Greenland were found to contain higher proportions of the higher chlorinated CB congeners. Varying patterns between sampling locations may be caused by different exposure situations related to contaminant emissions and transport, but different feeding habits may also affect the contaminant composition.
- Temporal development of brominated flame retardants in peregrine Falcon (Falco peregrinus) eggs from South Greenland (1986-2003). [Journal Article, Research Support, Non-U.S. Gov't]
- Environ Sci Technol 2005 Nov 1; 39(21):8199-206.
A time trend between 1986 and 2003 was found for brominated flame retardants in peregrine falcon eggs from South Greenland, with significantly increasing concentrations of the polybrominated diphenyl ethers (PBDEs) 99, 100, 153, 154, and 209. For BDE-99 and -100, the concentration increased approximately 10% per year. The concentrations of PBDEs were among the highest detected in wildlife so far and ranged from 300 to 12,900 ng/g lipid weight (lw) for sigmaPBDE. While tetrabromobisphenol A (TBBPA) was below the limit of detection in all eggs, hexabromocyclododecane (HBCD), dimethyl-TBBPA, and brominated biphenyl BB-153 were detected in a majority of eggs, with median concentrations of 2.4, 230, and 550 ng/g lw, respectively. Analyses of eggs of the same bird showed no significant intra-clutch variation for PBDEs, BB-153, and HBCD but larger variations for dimethyl-TBBPA. Inter-clutch variations with increasing time trends exist for the BDEs 99, 100, 153, 154, and 209, while a decreasing contamination with the BDEs 183, 49, 47, 66 and 153 was indicated in a subset of eggs.