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Carl-Eric Wegner, Werner Liesack
Acid mine drainage (AMD) and mine tailing environments are well-characterized ecosystems known to be dominated by organisms involved in iron- and sulfur-cycling. Here we examined the microbiology of industrial soft coal slags that originate from alum leaching, an ecosystem distantly related to AMD environments. Our study involved geochemical analyses, bacterial community profiling, and shotgun metagenomics. The slags still contained high amounts of alum constituents (aluminum, sulfur), which mediated direct and indirect effects on bacterial community structure...
2017: Frontiers in Microbiology
Heather Strosnider, Caitlin Kennedy, Michele Monti, Fuyuen Yip
PROBLEM/CONDITION: The places in which persons live, work, and play can contribute to the development of adverse health outcomes. Understanding the differences in risk factors in various environments can help to explain differences in the occurrence of these outcomes and can be used to develop public health programs, interventions, and policies. Efforts to characterize urban and rural differences have largely focused on social and demographic characteristics. A paucity of national standardized environmental data has hindered efforts to characterize differences in the physical aspects of urban and rural areas, such as air and water quality...
June 23, 2017: MMWR. Surveillance Summaries: Morbidity and Mortality Weekly Report. Surveillance Summaries
Peka Christova, Lisa M James, Brian E Engdahl, Scott M Lewis, Adam F Carpenter, Apostolos P Georgopoulos
Gulf War Illness (GWI) is a multisystem disorder that has affected a substantial number of veterans who served in the 1990-1991 Gulf War. The brain is prominently affected, as manifested by the presence of neurological, cognitive and mood symptoms. Although brain dysfunction in GWI has been well documented (EBioMedicine 12:127-32, 2016), abnormalities in brain structure have been debated. Here we report a substantial (~10%) subcortical brain atrophy in GWI comprising mainly the brainstem, cerebellum and thalamus, and, to a lesser extent, basal ganglia, amygdala and diencephalon...
June 20, 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Brodie Sutcliffe, Anthony A Chariton, Andrew J Harford, Grant C Hose, Greenfield Paul, Liam D H Elbourne, Yalchin Oytam, Sarah Stephenson, David J Midgley, Ian T Paulsen
Located in the Northern Territory of Australia, Ranger uranium mine is directly adjacent to the UNESCO World Heritage listed Kakadu National Park, with rehabilitation targets needed to ensure the site can be incorporated into the park following the mine's closure in 2026. This study aimed to understand the impact of uranium concentration on microbial communities, in order to identify and describe potential breakpoints in microbial ecosystem services. This is the first study to report in situ deployment of uranium-spiked sediments along a concentration gradient (0 - 4,000 mg U/kg), with the study design maximising the advantages of both field surveys and laboratory manipulative studies...
June 19, 2017: Environmental Microbiology
Mark C Phillips, Brian E Brumfield, Nicole LaHaye, Sivanandan S Harilal, Kyle C Hartig, Igor Jovanovic
We demonstrate measurement of uranium isotopes in femtosecond laser ablation plumes using two-dimensional fluorescence spectroscopy (2DFS). The high-resolution, tunable CW-laser spectroscopy technique clearly distinguishes atomic absorption from (235)U and (238)U in natural and highly enriched uranium metal samples. We present analysis of spectral resolution and analytical performance of 2DFS as a function of ambient pressure. Simultaneous measurement using time-resolved absorption spectroscopy provides information on temporal dynamics of the laser ablation plume and saturation behavior of fluorescence signals...
June 19, 2017: Scientific Reports
Ozan Artun
In the present study, we aimed at estimating the production of medical Ac-225 radionuclide via proton accelerator in the energy range Eproton=1000 →1MeV under certain conditions, on thorium target material instead of uranium due to the low abundant of uranium in nature. Hence, to produce the medical Ac-225, cross-section, separation energy was calculated by taking into account the proton induced reaction processes that were simulated to estimate activity and, yield of the product up to 1000MeV. Moreover, the calculated integral yields of reactions were presented...
June 10, 2017: Applied Radiation and Isotopes
David S Simons, John D Fassett
The determination of the relative isotopic abundance by secondary ion mass spectrometry of (236)U in uranium-containing material is complicated by the presence of (235)U(1)H(+) ions at the same nominal mass as the uranium isotopic peak. The net intensity of the (236)U signal is usually determined by a peak-stripping procedure, whereby the (235)U(1)H(+) contribution is obtained by applying the (238)U(1)H(+)/(238)U(+) ratio to the (235)U(+) signal. The subtraction of one signal from another has consequences for the uncertainty of the final (236)U abundance determination that may be especially significant when the amount of sample is limited, as is the case with small uranium particles that are of great interest for nuclear safeguards...
February 2017: Journal of Analytical Atomic Spectrometry
Alexandra C Miller, Rafael Rivas, Leonard Tesoro, Gregor Kovalenko, Nikola Kovaric, Peter Pavlovic, David Brenner
Depleted uranium (DU) is a radioactive heavy metal used primarily in military applications. Published data from our laboratory have demonstrated that DU exposure in vitro to immortalized human osteoblast cells (HOS) is both neoplastically transforming and genotoxic. In vivo studies have also demonstrated that DU is leukemogenic and genotoxic. DU possesses both a radiological (alpha particle) and chemical (metal) component but is generally considered a chemical biohazard. Studies have shown that alpha particle radiation does play a role in DU's toxic effects...
June 8, 2017: Toxicology and Applied Pharmacology
Christopher A Barrett, Wilaiwan Chouyyok, Robert J Speakman, Khris B Olsen, Raymond Shane Addleman
Environmental sampling to detect trace nuclear signatures is key component of international nuclear treaty enforcement. Herein, we explored rapid chemical extraction methods coordinated with measurement systems to provide faster, simpler assay of low level uranium from environmental samples. A key problem with the existing analytical method for processing environmental surface samples is the requirement for complete digestion of sample and sampling material. This is a time-consuming and labor-intensive process that limits laboratory throughput, elevates analytical costs, and increases background levels...
October 1, 2017: Talanta
Alex Marchenko, Lionel A Truflandier, Jochen Autschbach
Dynamic structural effects, NMR ligand chemical shifts, and (17)O NMR quadrupolar relaxation rates are investigated in the series of complexes UO2(2+), UO2(CO3)3(4-), and (UO2)3(CO3)6(6-). Car-Parrinello molecular dynamics (CPMD) is used to simulate the dynamics of the complexes in water. NMR properties are computed on clusters extracted from the CPMD trajectories. In the UO2(2+) complex, coordination at the uranium center by water molecules causes a decrease of around 300 ppm for the uranyl (17)O chemical shift...
June 9, 2017: Inorganic Chemistry
Zsolt Varga, Judit Krajkó, Maxim Peńkin, Márton Novák, Zsuzsanna Eke, Maria Wallenius, Klaus Mayer
The paper describes the applicability of different characteristics (signatures) in nuclear safeguards and forensics for assessment of uranium material provenance in terms of production process. The study follows a uranium ore concentrate production from an ore to a U3O8 product. It turned out that rare-earth elemental pattern, radiochronometry (age of ore body and material production date), sulphur and organic impurities are useful to find out the origin or history of the material, while certain trace-elements and isotopics of Pb or Sr were found to be inconclusive...
2017: Journal of Radioanalytical and Nuclear Chemistry
Daniel Richter, Rainer Grün, Renaud Joannes-Boyau, Teresa E Steele, Fethi Amani, Mathieu Rué, Paul Fernandes, Jean-Paul Raynal, Denis Geraads, Abdelouahed Ben-Ncer, Jean-Jacques Hublin, Shannon P McPherron
The timing and location of the emergence of our species and of associated behavioural changes are crucial for our understanding of human evolution. The earliest fossil attributed to a modern form of Homo sapiens comes from eastern Africa and is approximately 195 thousand years old, therefore the emergence of modern human biology is commonly placed at around 200 thousand years ago. The earliest Middle Stone Age assemblages come from eastern and southern Africa but date much earlier. Here we report the ages, determined by thermoluminescence dating, of fire-heated flint artefacts obtained from new excavations at the Middle Stone Age site of Jebel Irhoud, Morocco, which are directly associated with newly discovered remains of H...
June 7, 2017: Nature
Gregory Leinders, René Bes, Janne Pakarinen, Kristina Kvashnina, Marc Verwerft
A fundamental question concerning the chemical state of uranium in the binary oxides UO2, U4O9, U3O7, U3O8, and UO3 is addressed. By utilizing high energy resolution fluorescence detection X-ray absorption near edge spectroscopy (HERFD-XANES) at the uranium M4 edge, a novel technique in the tender X-ray region, we obtain the distribution of formal oxidation states in the mixed-valence oxides U4O9, U3O7, and U3O8. Moreover, we clearly identify a pivot from U(IV)-U(V) to U(V)-U(VI) charge compensation, corresponding with transition from a fluorite-type structure (U3O7) to a layered structure (U3O8)...
June 7, 2017: Inorganic Chemistry
Arpan Mukherjee, Garrett H Wheaton, James A Counts, Brenda Ijeomah, Jigar Desai, Robert M Kelly
When abruptly exposed to toxic levels of hexavalent uranium, the extremely thermoacidophilic archaeon Metallosphaera prunae, originally isolated from an abandoned uranium mine, ceased to grow, and concomitantly exhibited heightened levels of cytosolic ribonuclease activity that corresponded to substantial degradation of cellular RNA. The M. prunae transcriptome during 'uranium-shock' implicated VapC toxins as possible causative agents of the observed RNA degradation. Identifiable VapC toxins and PIN-domain proteins encoded in the M...
June 5, 2017: Environmental Microbiology
Muhammad Moazzam Naseer, Klaus Jurkschat
The field of anion recognition has developed into an area of tremendous significance over the recent decades due to the role of anions in biological and environmental systems, contributing significantly to the more general domain of supramolecular chemistry. So far, a number of receptors have been designed for anion recognition, synthesized and evaluated, most involving hydrogen bonding donors (urea, amide, pyrrole, imidazolium and hydroxyl groups), π-acidic aryl rings, Lewis acidic metals (boron, tin, aluminium, mercury and uranium) and positively charged polyammonium moieties...
June 5, 2017: Chemical Communications: Chem Comm
Golbarg M Roozbahani, Xiaohan Chen, Youwen Zhang, Ruiqi Xie, Rui Ma, Dien Li, Huazhong Li, Xiyun Guan
Uranium is one of the most common radioactive contaminants in the environment. As a major nuclear material in production, environmental samples (like soil and groundwater) can provide signatures on uranium production activity inside the facility. Thus, developing a new and portable analytical technology for uranium in aqueous media is significant not only for environmental monitoring, but also for nonproliferation. In this work, a label-free method for the detection of uranyl (UO2(2+)) ions is developed by monitoring the translocation of a peptide probe in a nanopore...
May 26, 2017: ACS Sensors
Amrita Bhattacharyya, Kate M Campbell, Shelly D Kelly, Yvonne Roebbert, Stefan Weyer, Rizlan Bernier-Latmani, Thomas Borch
Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U((VI))) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U((IV)) generated through biologically mediated U((VI)) reduction is the predominant U((IV)) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (∼58-89%) of U is bound as U((IV)) to C-containing organic functional groups or inorganic carbonate, while uraninite and U((VI)) represent only minor components...
June 1, 2017: Nature Communications
Sarah Ameziane-Le Hir, Damien Bourgeois, Christian Basset, Agnès Hagège, Claude Vidaud
Uranium is the heaviest natural element, mainly found in aqueous medium as the hexavalent uranyl ion (UO2(2+)). Bones are the main organs in which uranium accumulates, depending on as yet unknown molecular and cellular mechanisms. Recently, it has been revealed that osteopontin (OPN), a protein involved in bio-mineralization processes, and its main naturally occurring cleaved form (fOPN), have nanomolar affinities for UO2(2+). The binding of UO2(2+) is due to both the phosphorylation sites and acidic residues of these proteins and is accompanied by a slight gain in secondary structure...
May 31, 2017: Metallomics: Integrated Biometal Science
Viktor N Serezhkin, Mikhail S Grigoriev, Aleksey R Abdulmyanov, Aleksandr M Fedoseev, Anton V Savchenkov, Sergey Yu Stefanovich, Larisa B Serezhkina
X-ray diffraction was applied to the elucidation of crystal structures of single crystals of Cs2Ba[AnO2(C2H5COO)3]4, where An = U(I), Np(II), Pu(III), and KR2(H2O)8[UO2(C2H5COO)3]5, where R = Sr(IV), Ba (polymorphs V-a and V-b). FTIR spectra were analyzed for the uranium-containing crystals I, IV, and V-b. Isostructural cubic crystals I-III are constructed of typical mononuclear anionic complex units [AnO2(C2H5COO)3](-) and charge-balancing Cs and Ba cations. Features of actinide contraction in the six U-Np-Pu isostructural series known to date are analyzed...
May 31, 2017: Inorganic Chemistry
Joseph Hoover, Melissa Gonzales, Chris Shuey, Yolanda Barney, Johnnye Lewis
Regional water pollution and use of unregulated water sources can be an important mixed metals exposure pathway for rural populations located in areas with limited water infrastructure and an extensive mining history. Using censored data analysis and mapping techniques we analyzed the joint geospatial distribution of arsenic and uranium in unregulated water sources throughout the Navajo Nation, where over 500 abandoned uranium mine sites are located in the rural southwestern United States. Results indicated that arsenic and uranium concentrations exceeded national drinking water standards in 15...
2017: Expo Health
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