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1.
Water Res ; 210: 117987, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34954368

RESUMO

The Baltic Sea receives substantial amounts of hazardous substances and nutrients, which accumulate for decades and persistently impair the Baltic ecosystems. With long half-lives and high solubility, anthropogenic uranium isotopes (236U and 233U) are ideal tracers to depict the ocean dynamics in the Baltic Sea and the associated impacts on the fates of contaminants. However, their applications in the Baltic Sea are hampered by the inadequate source-term information. This study reports the first three-dimensional distributions of 236U and 233U in the Baltic Sea (2018-2019) and the first long-term hindcast simulation for reprocessing-derived 236U dispersion in the North-Baltic Sea (1971-2018). Using 233U/236U fingerprints, we distinguish 236U from the nuclear weapon testing and civil nuclear industries, which have comparable contributions (142 ± 13 and 174 ± 40 g) to the 236U inventory in modern Baltic seawater. Budget calculations for 236U inputs since the 1950s indicate that, the major 236U sources in the Baltic Sea are the atmospheric fallouts (∼1.35 kg) and discharges from nuclear reprocessing plants (> 211 g), and there is a continuous sink of 236U to the anoxic sediments (589 ± 43 g). Our findings also indicate that the limited water renewal endows the Baltic Sea a strong "memory effect" retaining aged 236U signals, and the previously unknown 236U in the Baltic Sea is likely attributed to the retention of the mid-1990s' discharges from the nuclear reprocessing plants. Our preliminary results demonstrate the power of 236U-129I dual-tracer in investigating water-mass mixing and estimating water age in the Baltic Sea, and this work provides fundamental knowledge for future 236U tracer studies in the Baltic Sea.


Assuntos
Poluentes Radioativos da Água , Países Bálticos , Simulação por Computador , Ecossistema , Água do Mar , Poluentes Radioativos da Água/análise
2.
Appl Radiat Isot ; 147: 197-203, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30909024

RESUMO

A method for caesium concentration from North Sea and Baltic Sea seawater samples was tested and optimised for offshore concentration of radiocaesium and seawater volumes up to 150 L. The composite ion-exchanger PotassiumNickel Hexacyanoferrate in a Polyacrylnitrile binding matrix (KNiFC-PAN) with 80% of powdered KNiFC per gram of dry residue was used for this study. The optimised method achieved recoveries of around 99% with a bed volume (BV) of 50 mL of KNiFC-PAN and average flow rates of seawater of around 182 BV per hour (e.g. 9.1 L per hour).


Assuntos
Radioisótopos de Césio/análise , Monitoramento de Radiação/métodos , Água do Mar/química , Poluentes Radioativos da Água/análise
3.
Appl Radiat Isot ; 70(8): 1595-602, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22738834

RESUMO

We aim to date ivory samples by determination of the concentration of (14)C in the sample. However, such data do not always represent unambiguous evidence. In these cases other nuclides have to be additionally analyzed which causes additional costs. To make the dating method still affordable, the direct CO(2) absorption method for analyzing (14)C was tested. Results show that this method has a precision of about 4.0% (95% confidence level) which is good enough for this purpose.

4.
Forensic Sci Int ; 221(1-3): 5-10, 2012 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-22717552

RESUMO

A method is described to determine the time of death of elephants. This is accomplished by analysis of the radionuclides 14C, 90Sr and 228/232Th in known samples of ivory, and in samples of unknown age. The reliability of this method is considerably increased by multi nuclide analysis.


Assuntos
Radioisótopos de Carbono/análise , Conservação dos Recursos Naturais , Elefantes , Radioisótopos/análise , Radioisótopos de Estrôncio/análise , Tório/análise , Animais , Comércio/legislação & jurisprudência , Crime , Espectrometria de Massas , Conceitos Matemáticos
5.
PLoS One ; 6(9): e24106, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21931648

RESUMO

As part of the European research consortium IBDase, we addressed the role of proteases and protease inhibitors (P/PIs) in inflammatory bowel disease (IBD), characterized by chronic mucosal inflammation of the gastrointestinal tract, which affects 2.2 million people in Europe and 1.4 million people in North America. We systematically reviewed all published genetic studies on populations of European ancestry (67 studies on Crohn's disease [CD] and 37 studies on ulcerative colitis [UC]) to identify critical genomic regions associated with IBD. We developed a computer algorithm to map the 807 P/PI genes with exact genomic locations listed in the MEROPS database of peptidases onto these critical regions and to rank P/PI genes according to the accumulated evidence for their association with CD and UC. 82 P/PI genes (75 coding for proteases and 7 coding for protease inhibitors) were retained for CD based on the accumulated evidence. The cylindromatosis/turban tumor syndrome gene (CYLD) on chromosome 16 ranked highest, followed by acylaminoacyl-peptidase (APEH), dystroglycan (DAG1), macrophage-stimulating protein (MST1) and ubiquitin-specific peptidase 4 (USP4), all located on chromosome 3. For UC, 18 P/PI genes were retained (14 proteases and 4 protease inhibitors), with a considerably lower amount of accumulated evidence. The ranking of P/PI genes as established in this systematic review is currently used to guide validation studies of candidate P/PI genes, and their functional characterization in interdisciplinary mechanistic studies in vitro and in vivo as part of IBDase. The approach used here overcomes some of the problems encountered when subjectively selecting genes for further evaluation and could be applied to any complex disease and gene family.


Assuntos
Predisposição Genética para Doença/genética , Doenças Inflamatórias Intestinais/genética , Peptídeo Hidrolases/genética , Inibidores de Proteases , Bases de Dados de Proteínas , Enzima Desubiquitinante CYLD , Distroglicanas/genética , Estudo de Associação Genômica Ampla , Fator de Crescimento de Hepatócito/genética , Humanos , Proteínas Proto-Oncogênicas/genética , Proteínas Supressoras de Tumor/genética , Ubiquitina Tiolesterase/genética , Proteases Específicas de Ubiquitina
6.
Forensic Sci Int ; 207(1-3): e1-4, 2011 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-21371831

RESUMO

A method is described to determine whether an elephant has died before 1955 or not. This is accomplished by determination of the radionuclides (14)C and (90)Sr in artifacts made of ivory. The reliability of this method is considerably increased by double nuclide analysis and therefore is applicable for judicial expert opinions.


Assuntos
Radioisótopos de Carbono/análise , Comércio/legislação & jurisprudência , Elefantes , Radioisótopos de Estrôncio/análise , Animais , Cálcio/análise , Crime , Espécies em Perigo de Extinção , Limite de Detecção , Contagem de Cintilação , Fatores de Tempo
7.
PLoS One ; 4(3): e4839, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19325907

RESUMO

BACKGROUND: The intracellular protozoan parasite Theileria parva transforms bovine lymphocytes inducing uncontrolled proliferation. Proteins released from the parasite are assumed to contribute to phenotypic changes of the host cell and parasite persistence. With 85 members, genes encoding subtelomeric variable secreted proteins (SVSPs) form the largest gene family in T. parva. The majority of SVSPs contain predicted signal peptides, suggesting secretion into the host cell cytoplasm. METHODOLOGY/PRINCIPAL FINDINGS: We analysed SVSP expression in T. parva-transformed cell lines established in vitro by infection of T or B lymphocytes with cloned T. parva parasites. Microarray and quantitative real-time PCR analysis revealed mRNA expression for a wide range of SVSP genes. The pattern of mRNA expression was largely defined by the parasite genotype and not by host background or cell type, and found to be relatively stable in vitro over a period of two months. Interestingly, immunofluorescence analysis carried out on cell lines established from a cloned parasite showed that expression of a single SVSP encoded by TP03_0882 is limited to only a small percentage of parasites. Epitope-tagged TP03_0882 expressed in mammalian cells was found to translocate into the nucleus, a process that could be attributed to two different nuclear localisation signals. CONCLUSIONS: Our analysis reveals a complex pattern of Theileria SVSP mRNA expression, which depends on the parasite genotype. Whereas in cell lines established from a cloned parasite transcripts can be found corresponding to a wide range of SVSP genes, only a minority of parasites appear to express a particular SVSP protein. The fact that a number of SVSPs contain functional nuclear localisation signals suggests that proteins released from the parasite could contribute to phenotypic changes of the host cell. This initial characterisation will facilitate future studies on the regulation of SVSP gene expression and the potential biological role of these enigmatic proteins.


Assuntos
Linfócitos/parasitologia , Proteínas de Protozoários/genética , Theileria parva/genética , Animais , Linfócitos B/parasitologia , Bovinos , Perfilação da Expressão Gênica , Proteínas de Protozoários/metabolismo , RNA de Protozoário/análise , Linfócitos T/parasitologia , Theileria parva/química , Theileria parva/patogenicidade
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