| 1. |
- Bengtsson, Göran, et al.
(author)
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PIXE-electrophoresis shows starving collembolan reallocates protein-bound metals.
- 2015
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In: Ecotoxicology. - : Springer Science and Business Media LLC. - 1573-3017 .- 0963-9292.
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Journal article (peer-reviewed)abstract
- One of multiple functions of metalloproteins is to provide detoxification to excess metal levels in organisms. Here we address the induction and persistence of a range of low to high molecular weight copper- and zinc binding proteins in the collembolan species Tetrodontophora bielanensis exposed to copper- and zinc-enriched food, followed by a period of recovery from metal exposure, in absence and presence of food. After 10 days of feeding copper and zinc contaminated yeast, specimens were either moved to ample of leaf litter material from their woodland stand of origin or starved (no food offered). The molecular weight distribution of metal binding proteins was determined by native polyacryl gel electrophoresis. One gel was stained with Comassie brilliant blue and a duplicate gel dried and scanned for the amount of copper and zinc by particle-induced X-ray emission. Specimens exposed to copper and recovered from it with ample of food had copper bound to two groups of rather low molecular weight proteins (40-50 kDa) and two of intermediate size (70-80 kDa). Most zinc in specimens from the woodland stand was bound to two large proteins of about 104 and 106 kDa. The same proteins were holding some zinc in metal-exposed specimens, but most zinc was found in proteins <40 kDa in size. Specimens recovered from metal exposure in presence of ample of food had the same distribution pattern of zinc binding proteins, whereas starved specimens had zinc as well as copper mainly bound to two proteins of 8 and 10 kDa in size. Thus, the induction and distribution of copper- and zinc-binding proteins depend on exposure conditions, and the presence of low molecular weight binding proteins, characteristic of metallothioneins, was mainly limited to starving conditions.
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| 2. |
- Borysiuk, Maciek, et al.
(author)
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Preliminary results of oxygen isotope ratio measurement with a particle-gamma coincidence method
- 2015
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In: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 348, s. 269-272
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Journal article (peer-reviewed)abstract
- The possibility to study variations in the oxygen isotopic ratio with photon tagged nuclear reaction analysis (pNRA) is evaluated in the current work. The experiment described in the article was performed at Lund Ion Beam Analysis Facility (LIBAF) with a 2 MeV deuteron beam. Isotopic fractionation of light elements such as carbon, oxygen and nitrogen is the basis of many analytical tools in hydrology, geology, paleobiology and paleogeology. IBA methods provide one possible tool for measurement of isotopic content. During this experimental run we focused on measurement of the oxygen isotopic ratio. The measurement of stable isotopes of oxygen has a number of applications; the particular one driving the current investigation belongs to the field of astrogeology and specifically evaluation of fossil extraterrestrial material. There are three stable isotopes of oxygen; O-16, O-17 and O-18. We procured samples highly enriched with all three isotopes. Isotopes O-16 and O-18 were easily detected in the enriched samples, but no significant signal from O-17 was detected in the same samples. The measured yield was too low to detect O-18 in a sample with natural abundances of oxygen isotopes, at least in the current experimental setup, but the spectral line from the reaction with O-16 was clearly visible. (C) 2015 Elsevier B.V. All rights reserved.
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| 3. |
- Cederlund, Martin, et al.
(author)
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A1M/α1-microglobulin is proteolytically activated by myeloperoxidase, binds its heme group and inhibits low density lipoprotein oxidation.
- 2015
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In: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 6
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Journal article (peer-reviewed)abstract
- α1-microglobulin (A1M) is a 26 kDa plasma and tissue protein with reductase activity and radical- and heme-binding anti-oxidative functions. In addition, exposure of A1M to hemoglobin has been shown to induce proteolytic elimination of a C-terminal tetrapeptide yielding a heme-degrading form, truncated A1M (t-A1M). Myeloperoxidase (MPO), a heme-containing enzyme that catalyzes the production of free radicals and hypochlorite, is released by neutrophils during the inflammatory response to bacterial infections. MPO-induced low density lipoprotein (LDL)-oxidation in blood has been suggested as a causative factor in atherosclerosis. In this study we have hypothesized that A1M interacts with MPO in a similar mode as with hemoglobin, and is a regulator of its activity. The results show that A1M is proteolytically cleaved, with formation of t-A1M, after exposure to MPO, and that t-A1M contains iron and heme-degradation products. The reaction is dependent of pH, time and concentration of substrates and a pH-value around 7 is shown to be optimal for cleavage. Furthermore, A1M inhibits MPO- and hydrogen peroxide-induced oxidation of LDL. The results suggest that A1M may have a role as an inhibitor of the damaging effects of the neutrophil respiratory burst on bystander tissue components.
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| 4. |
- De La Rosa, Nathaly, et al.
(author)
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Lithium analysis using a double-sided silicon strip detector at LIBAF
- 2017
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In: Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 404, s. 29-33
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Journal article (peer-reviewed)abstract
- Quantification and mapping possibilities of lithium in geological material, by Nuclear Reaction Analysis (NRA), was evaluated at the Lund Ion Beam Analysis Facility (LIBAF). LiF and two Standard Reference Materials, (SRM 610 and SRM 612) were used in the investigation. The main part of the data was obtained at the beam energy 635keV studying the high Q-value reaction 7Li(p, α)4He, but reaction yield and detection limits were also briefly investigated as a function of the energy. A double-sided silicon strip detector (DSSSD) was used to detect the α-particles emitted in the reaction in the backward direction. The combination of the high Q-value, a reasonably good cross-section and the possibility to use a high beam current have been demonstrated to allow for measurement of concentrations down below 50ppm. Proton energies below 800keV were demonstrated to be appropriate energies for extracting lithium in combination with boron analysis.
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| 5. |
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| 6. |
- de la Rosa, Nathaly, et al.
(author)
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Quantification of lithium at ppm level in geological samples using nuclear reaction analysis
- 2018
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In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 317:1, s. 253-259
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Journal article (peer-reviewed)abstract
- Proton-induced reaction (p,α) is one type of nuclear reaction analysis (NRA) suitable especially for light element quantification. In the case of lithium quantification presented in this work, accelerated protons with an energy about of 850 keV were used to induce the 7Li(p,α)4He reaction in standard reference and geological samples such as tourmaline and other Li-minerals. It is shown that this technique for lithium quantification allowed for measurement of concentrations down below one ppm. The possibility to relate the lithium content with the boron content in a single analysis was also demonstrated using tourmaline samples, both in absolute concentration and in lateral distribution. In addition, Particle induced X-ray emission (PIXE) was utilized as a complementary IBA technique for simultaneous mapping of elements heavier than sodium.
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| 7. |
- Elfman, Mikael, et al.
(author)
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A tailored 200 parameter VME based data acquisition system for IBA at the Lund Ion Beam Analysis Facility - Hardware and software
- 2016
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In: Nuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. - : Elsevier BV. - 0168-583X. ; 371, s. 148-152
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Journal article (peer-reviewed)abstract
- With the recent advances towards modern Ion Beam Analysis (IBA), going from one- or few-parameter detector systems to multi-parameter systems, it has been necessary to expand and replace the more than twenty years old CAMAC based system. A new VME multi-parameter (presently up to 200 channels) data acquisition and control system has been developed and implemented at the Lund Ion Beam Analysis Facility (LIBAF). The system is based on the VX-511 Single Board Computer (SBC), acting as master with arbiter functionality and consists of standard VME modules like Analog to Digital Converters (ADC's), Charge to Digital Converters (QDC's), Time to Digital Converters (TDC's), scaler's, IO-cards, high voltage and waveform units. The modules have been specially selected to support all of the present detector systems in the laboratory, with the option of future expansion. Typically, the detector systems consist of silicon strip detectors, silicon drift detectors and scintillator detectors, for detection of charged particles, X-rays and γ-rays. The data flow of the raw data buffers out from the VME bus to the final storage place on a 16 terabyte network attached storage disc (NAS-disc) is described. The acquisition process, remotely controlled over one of the SBCs ethernet channels, is also discussed. The user interface is written in the Kmax software package, and is used to control the acquisition process as well as for advanced online and offline data analysis through a user-friendly graphical user interface (GUI). In this work the system implementation, layout and performance are presented. The user interface and possibilities for advanced offline analysis are also discussed and illustrated.
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| 8. |
- Kristensson, Adam, et al.
(author)
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Metaller i luftburna partiklar i Landskrona 2017
- 2019
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Reports (other academic/artistic)abstract
- Mellan 16 februari och 22 mars 2017 genomfördes 24 mätningar av finfraktionen (PM2.5) och grovfraktionen (PM10 – PM2.5) av grundämnen i luftburna partiklar på mätstationerna i Stadshuset och Lundåkrahamnen i Landskrona. Detta gjordes som ett led i att kontrollera luftkvaliten i Landskrona stad, särskilt med tanke på industrierna i Landskrona, som tidigare har givit höga halter av framförallt metaller i luften för åren 1977, 1988, 2003, och 2008. Bägge mätstationerna representerar urbana bakgrundsstationer, där Stadshusets mätningar är i trafikmiljö, medan Lundåkrahamnens mätningar är i industriområde.Flertalet ämnen kunde detekteras med PIXE-analysmetoden; Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, Br, Sr, Pb. V och As låg mestadels under detektionsgränsen. Ga, Ge, Se, Rb, Y, Zr, Pd, Cd, och Sn var aldrig detekterbara.För grovfraktionen både vid Stadshuset och Lundåkrahamnen har mätningar under år 2008 generellt gett de lägsta partikelhlaterna. Förutom detta år har det rent generellt varit en nedåtgående trend för halterna för följande ämnen sedan 1977; K, Ca, Ti, Mn, Fe, Ni, Zn, och Pb. Nästan oförändrade halter har observerats för Al, Si, S, Cu, och Br. Halterna av Cl och Cr har rent av gått upp. Det bör dock nämnas att Cl kommer från den naturliga källan havssprej, varför halterna av Cl och andra naturliga ämnen mer beror på meteorologiska förutsättningar än minskningar i mänskliga utsläpp. För finfraktionen har vi nedåtgående trend sedan 1977 för; S, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, och Pb. Oförändrade halter för Cr, och uppåtgående trend för Cl.P mättes för första gången både i grov- och finfraktion. Detta ämne kan till exempel komma från jordstoftpartiklar, samt från havet (övergödning). Men, ingen vidare korrelation kunde skönjas med jordstoftpartiklar och havssprejpartiklar. Ämnet har betydelse för bördiga jordar och övergödning, varför det är viktigt att fortsätta mäta detta ämne.Käll/receptor-modellering har utförts för att beräkna källtilldelningen. PMF-modellen kördes med en lätt polarisering av källorna (FPEAK-paramter = 0.5) och för grovfraktion och finfraktion för sig, och de två stationerna var och en för sig. Det gjordes alltså 4 olika PMF-körningar.Resultaten visade att vi i princip har 7 olika källor för partiklar och grundämneselement i Landskrona;1. Havssprej2. Jordstoftpartiklar3. Pb-källa4. Fe/Zn-källa5. Cr/Ni-källa6. Cu/Zn-källa7. Åldrad källaHavssprej både i Stadshuset och Lundåkrahamnen utgörs av grova partiklar med Cl, Br som främsta ämnen. Även finfraktionen innehåller en hög halt Cl och Br, vilket förmodligen beror på att även finfraktionen innehåller en relativt hög andel grova partiklar. Högsta halterna är förknippade med havsluft västerifrån.Jorstoftpartiklar karakteriseras av elementen Si, K, Ca, Ti, och Fe, vilka är typiska för jordskorpan. Framförallt grova partiklar ger höga halter av dessa ämnen, men även finfraktionen kan innehålla en andel grova partiklar liksom havssprejkällan.Pb-källan är förknippad med vindar från Boliden-Bergsoe-fabriken, vilket den även har varit för föregående mätningar, både vid Stadshuset och Lundåkrahamnen, såväl i fin- som i grovfraktionen.Fe/Zn-källan är vid några tillfällen associerad med vindar från hamnområdet eller Scandust, för både grov- och finfraktionen i Stadshuset och Lundåkrahamnen. Det går dock inte att härleda denna källa till specifik aktivitet i detta område i Landskrona. En del av Fe/Zn-källan samvarierar med jordsoftkällan, vilket bevisar att en del av Fe och Zn kommer från jordstoft. Detta är väntat eftersom jordskorpan även innehåller dessa element.Liknande resonemang gäller för Cr/Ni-källan. Vi kan dessutom inte utesluta att Cr/Ni i finfraktionen dessutom kommer från långdistanstransport av fossila förbränningspartiklar, eftersom fossil olja ofta innehåller Cr och Ni.Återigen gäller liknande resonemang för Cu/Zn-källan. Dessutom är det möjligt att en del Cu/Zn-damm och fina partiklar möjligen härstammar från färgborttagning från småbåtar och målning.Den sista källan är en långdistanstransporterad källa innehållandes S, framförallt i finfraktionen. Denna kommer från kondensation av svaveldioxid eller svavelsyra under långdistanstransport under flera timmar eller dygn (sekundär källa), eller direkt under förbränning av fossila bränslen (primär källa). Man kan förvänta sig att denna källa har minskat i och med regleringen av sulfatinnehållet i sjöfartsbränslet sedan 2015 i Östersjön och Nordsjön, eller generellt bättre rening av S från kolkraftverk eller andra industrier med förbränningsprocesser sedan konventionen om gränsöverskridande luftföroreningar (CLRTAP) kom igång ordentligt på 80-talet. En svag trend är synlig. Å andra sidan kan variationer i S bero på variationer i meteorologiska förhållanden, och inte enbart på grund av utsläppsminskningar.
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| 9. |
- Nilsson, Charlotta, et al.
(author)
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A nuclear geochemical analysis system for boron quantification using a focused ion beam
- 2017
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In: Journal of Radioanalytical and Nuclear Chemistry. - : Springer Science and Business Media LLC. - 0236-5731 .- 1588-2780. ; 311:1, s. 355-364
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Journal article (peer-reviewed)abstract
- Ion beam analysis has for decades been used as a tool for geochemical analysis of trace elements using both X-rays (particle induced X-ray emission) and nuclear reaction analysis. With the geoanalytical setup at the Lund Ion Beam Analysis Facility, the boron content in geological samples with a spatial resolution of 1 µm is determined through nuclear reaction analysis. In the newly upgraded setup, a single detector has been replaced by a double sided silicon strip detector with 2048 segments. After optimization, boron content in geological samples as low as 1 µg g−1 can be measured.
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| 10. |
- Pallon, Jan, et al.
(author)
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A new quantitative X-ray system for micro-PIXE analysis
- 2017
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In: X-Ray Spectrometry. - : Wiley. - 0049-8246. ; 46:5, s. 319-324
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Journal article (peer-reviewed)abstract
- Particle Induced X-ray Emission is a well-established technique for quantitative elemental analysis down to trace levels. During microbeam analysis, where the beam is collimated and focused into a small spot, the beam current reduces to nA or less. The generation of characteristic X-rays is reduced in the same proportion, leading to long data-acquisition times. This can partly be compensated for by using detectors with a large solid angle. In this work, the performance of an annular eight-element silicon drift detector with a total solid angle of 261 msr is described. The initial calibration of the detector was performed using thin elemental standards. Charge measurement was carried out both in a Faraday Cup positioned after the sample and by a pre-sample electrostatic deflection system sampling the beam charge into another Faraday Cup. The two methods were used in parallel and compared during the calibration measurements. A recently installed Versa Module Europe (VME) based data acquisition system equipped with, for example, multi-hit time-to-digital converters, amplifiers, and 32-channel scalers, was used to record data in event-by-event mode for simultaneous data evaluation on multiple computers. Off-line dead time and pile-up corrections were made on the event data that was sorted into spectra and fitted with the GeoPIXE software. The pre-sample deflection charge measurement gave consistent values for the calibration, and this is an important observation implying that non-conductive and thick samples will be able to quantify without the use of internal standards.
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