The Columbia University proton-induced soft x-ray microbeam.

PubMed

Harken, Andrew D; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

2011-09-15

A soft x-ray microbeam using proton-induced x-ray emission (PIXE) of characteristic titanium (K(α) 4.5 keV) as the x-ray source has been developed at the Radiological Research Accelerator Facility (RARAF) at Columbia University. The proton beam is focused to a 120 μm × 50 μm spot on the titanium target using an electrostatic quadrupole quadruplet previously used for the charged particle microbeam studies at RARAF. The proton induced x-rays from this spot project a 50 μm round x-ray generation spot into the vertical direction. The x-rays are focused to a spot size of 5 μm in diameter using a Fresnel zone plate. The x-rays have an attenuation length of (1/e length of ~145 μm) allowing more consistent dose delivery across the depth of a single cell layer and penetration into tissue samples than previous ultra soft x-ray systems. The irradiation end station is based on our previous design to allow quick comparison to charged particle experiments and for mixed irradiation experiments.

A new ion beam facility based on a 3 MV Tandetron™ at IFIN-HH, Romania

NASA Astrophysics Data System (ADS)

Burducea, I.; Straticiuc, M.; Ghiță, D. G.; Moșu, D. V.; Călinescu, C. I.; Podaru, N. C.; Mous, D. J. W.; Ursu, I.; Zamfir, N. V.

2015-09-01

A 3 MV Tandetron™ accelerator system has been installed and commissioned at the "Horia Hulubei" National Institute for Physics and Nuclear Engineering - IFIN-HH, Măgurele, Romania. The main purpose of this machine is to strengthen applied nuclear physics research ongoing in our institute for more than four decades. The accelerator system was developed by High Voltage Engineering Europa B.V. (HVE) and comprises three high energy beam lines. The first beam line is dedicated to ion beam analysis (IBA) techniques: Rutherford Backscattering Spectrometry - RBS, Nuclear Reaction Analysis - NRA, Particle Induced X-ray and γ-ray Emission - PIXE and PIGE and micro-beam experiments - μ-PIXE. The second beam line is dedicated to high energy ion implantation experiments and the third beam line was designed mainly for nuclear cross-sections measurements used in nuclear astrophysics. A unique feature, the first time in operation at an accelerator facility is the Na charge exchange canal (CEC), which is used to obtain high intensity beams of He- of at least 3 μA. The results of the acceptance tests demonstrate the huge potential of this new facility in various fields, from IBA to radiation hardness studies and from medical or environmental applications to astrophysics. The main features of the accelerator are presented in this paper.

A microPIXE investigation of the interaction of cells of Schizosaccharomyces pombe with the culture medium

NASA Astrophysics Data System (ADS)

Rombouts, P. M. M.; Gomez-Morilla, I.; Grime, G. W.; Webb, R. P.; Cuenca, L.; Rodriguez, R.; Browton, M.; Wardell, N.; Underwood, B.; Kirkby, N. F.; Kirkby, K. J.

2007-07-01

Schizosaccharomyces pombe ( S. pombe) is a eucaryotic cell type similar to mammalian cells but much more simple. As it also executes its cell cycle rapidly it is very useful for investigating basic processes in cells. In this paper we report a feasibility study of the applicability of microPIXE to investigate the interaction between S. pombe cells and the surrounding culture medium. Cells were cultured in various growth medium prior to preparation for analysis. 1 μl drops of medium and cells were spotted onto polypropylene foils held in contact with a polished copper block previously cooled in liquid nitrogen. The samples were dehydrated by freeze-drying. Micro PIXE analysis was carried out with the IBC microbeam facility using a beam of 2.5 MeV protons focused to 1-2 μm diameter. Initially no elemental contrast was observed between the cells and the medium, but by modifying the dilution of the cell suspension, the cells could be distinguished from the surrounding medium through an increased concentration of P and reduced concentration of Cl. The distribution of Na in the medium around the cells showed evidence of the action of the Na pump. Sporulation appears to be induced in the cells by adding Cu to the growth medium and the uptake of Cu by the cells could be clearly observed. This study shows that it is possible to analyse the mass transport of elements in and out of cells In the future this will enable concentration gradients to be analysed and allow the rate of production or consumption of individual cells to be calculated. By observing these patterns for individual cells (not populations) at various known points in the cell cycle, fundamental data can be derived.

Surface topography of 1€ coin measured by stereo-PIXE

NASA Astrophysics Data System (ADS)

Gholami-Hatam, E.; Lamehi-Rachti, M.; Vavpetič, P.; Grlj, N.; Pelicon, P.

2013-07-01

We demonstrate the stereo-PIXE method by measurement of surface topography of the relief details on 1€ coin. Two X-ray elemental maps were simultaneously recorded by two X-ray detectors positioned at the left and the right side of the proton microbeam. The asymmetry of the yields in the pixels of the two X-ray maps occurs due to different photon attenuation on the exit travel path of the characteristic X-rays from the point of emission through the sample into the X-ray detectors. In order to calibrate the inclination angle with respect to the X-ray asymmetry, a flat inclined surface model was at first applied for the sample in which the matrix composition and the depth elemental concentration profile is known. After that, the yield asymmetry in each image pixel was transferred into corresponding local inclination angle using calculated dependence of the asymmetry on the surface inclination. Finally, the quantitative topography profile was revealed by integrating the local inclination angle over the lateral displacement of the probing beam.

In vivo 3D PIXE-micron-CT imaging of Drosophila melanogaster using a contrast agent

NASA Astrophysics Data System (ADS)

Matsuyama, Shigeo; Hamada, Naoki; Ishii, Keizo; Nozawa, Yuichiro; Ohkura, Satoru; Terakawa, Atsuki; Hatori, Yoshinobu; Fujiki, Kota; Fujiwara, Mitsuhiro; Toyama, Sho

2015-04-01

In this study, we developed a three-dimensional (3D) computed tomography (CT) in vivo imaging system for imaging small insects with micrometer resolution. The 3D CT imaging system, referred to as 3D PIXE-micron-CT (PIXEμCT), uses characteristic X-rays produced by ion microbeam bombardment of a metal target. PIXEμCT was used to observe the body organs and internal structure of a living Drosophila melanogaster. Although the organs of the thorax were clearly imaged, the digestive organs in the abdominal cavity could not be clearly discerned initially, with the exception of the rectum and the Malpighian tubule. To enhance the abdominal images, a barium sulfate powder radiocontrast agent was added. For the first time, 3D images of the ventriculus of a living D. melanogaster were obtained. Our results showed that PIXEμCT can provide in vivo 3D-CT images that reflect correctly the structure of individual living organs, which is expected to be very useful in biological research.

Nuclear physics for materials technology

NASA Astrophysics Data System (ADS)

Conlon, T. W.

1987-04-01

Although particle accelerators have traditionally been used to further our knowledge of nuclear physics, the last decade or so has seen a rapid growth of their involvement in materials technology — both to modify materials and to provide analytical information at the atomic level that cannot be obtained in other ways. The deployment of ion beams in these areas has occurred in three phases: first the exploitation of keV ion beams (in ion implantation and SIMS) then MeV light ion beams (using RBS, NRA, PIXE analysis and TLA) and currently MeV heavy ion beams, together with the associated fast recoil atoms and nuclei that they produce in interactions with materials. This trend has been accompanied by the gradual assimilation of methods such as energy analysis, microbeam focussing, particle identification, time of flight and coincidence techniques, etc., which were first developed for experimental nuclear physics use. Current examples of developments in the MeV range relevant to phases 2 and 3 are given.

A comparison of two micro-beam X-ray emission techniques for actinide elemental distribution in microscopic particles originating from the hydrogen bombs involved in the Palomares (Spain) and Thule (Greenland) accidents

NASA Astrophysics Data System (ADS)

Jimenez-Ramos, M. C.; Eriksson, M.; García-López, J.; Ranebo, Y.; García-Tenorio, R.; Betti, M.; Holm, E.

2010-09-01

In order to validate and to gain confidence in two micro-beam techniques: particle induced X-ray emission with nuclear microprobe technique (μ-PIXE) and synchrotron radiation induced X-ray fluorescence in a confocal alignment (confocal SR μ-XRF) for characterization of microscopic particles containing actinide elements (mixed plutonium and uranium) a comparative study has been performed. Inter-comparison of the two techniques is essential as the X-ray production cross-sections for U and Pu are different for protons and photons and not well defined in the open literature, especially for Pu. The particles studied consisted of nuclear weapons material, and originate either in the so called Palomares accident in Spain, 1966 or in the Thule accident in Greenland, 1968. In the determination of the average Pu/U mass ratios (not corrected by self-absorption) in the analysed microscopic particles the results from both techniques show a very good agreement. In addition, the suitability of both techniques for the analysis with good resolution (down to a few μm) of the Pu/U distribution within the particles has been proved. The set of results obtained through both techniques has allowed gaining important information concerning the characterization of the remaining fissile material in the areas affected by the aircraft accidents. This type of information is essential for long-term impact assessments of contaminated sites.

EUTERPE, a small electron storage ring for XRF

NASA Astrophysics Data System (ADS)

Botman, J. I. M.; Mutsaers, P. H. A.; Hagedoorn, H. L.; De Voigt, M. J. A.

1990-04-01

A small-sized electron storage ring is under construction at the Eindhoven University of Technology which will cover the energy range of 15 to 400 MeV. At top energy the characteristic wavelength of the synchrotron radiation spectrum is 8.3 nm for the regular dipole magnets and 1.2 nm corresponding to 1.06 keV for a 10 T wiggler magnet. This will provide useful radiation for X-ray fluorescence (XRF) up to 3.2 keV. Alternatively, photon conversion with a high power CO 2 laser beam of 0.124 eV photons will generate X-rays for XRF with energies ranging from 0.5 to 300 keV, depending on the operating energy of the storage ring. This facility will provide an important extension to the activities of the Eindhoven group on PIXE, RBS and microbeam analysis. A short description of the macnine will be given together with applications and specific examples of the XRF method.

Materials characterization with MeV ions

NASA Astrophysics Data System (ADS)

Conlon, T. W.

1989-04-01

The inherent atomic and nuclear properties of energetic ions in materials can be exploited to characterize as well as to modify materials' properties. In nuclear reactors keV ions from neutron collisions damage containment materials. However, basic studies of the interactions of such ions has yielded improved understanding of their properties and has even led to a tailoring of conditions so that the ions can be made to beneficially modify structures (by ion implantation). At higher energies an understanding of the ion-material interaction provides techniques such as PIXE, RBS, and ERD for nondestructive analysis, either in broad beam or "microbeam" mode. At high energies still penetration of the Coulomb barrier opens up activation methods for materials' characterization (CPAA, NRA, TLA etc.). A short discussion of the general properties of energetic ions in materials is followed by a brief introduction to our generic work in these areas, and some examples of current work in the areas of: activation for the radioisotope labelling of nonmetals, mass resolved ERDA using TOF techniques and submicron MeV microprobes.

Standardisation of the ion beam facility at Chandigarh cyclotron for simultaneous PIXE and PESA analysis

NASA Astrophysics Data System (ADS)

Verma, Shivcharan; Mohanty, Biraja P.; Singh, Karn P.; Kumar, Ashok

2018-02-01

The proton beam facility at variable energy cyclotron (VEC) Panjab University, Chandigarh, India is being used for Particle Induced X-ray Emission (PIXE) analysis of different environmental, biological and industrial samples. The PIXE method, however, does not provide any information of low Z elements like carbon, nitrogen, oxygen and fluorine. As a result of the increased need for rapid and multi-elemental analysis of biological and environmental samples, the PIXE facility was upgraded and standardized to facilitate simultaneous measurements using PIXE and Proton Elastic Scattering Analysis (PESA). Both PIXE and PESA techniques were calibrated and standardized individually. Finally, the set up was tested by carrying out simultaneous PIXE and PESA measurements using a 2 mm diameter proton beam of 2.7 MeV on few multilayered thin samples. The results obtained show excellent agreement between PIXE and PESA measurements and confirm adequate sensitivity and precision of the experimental set up.

Examining the diagenetic alteration of human bone material from a range of archaeological burial sites using nuclear microscopy

NASA Astrophysics Data System (ADS)

Elliott, T. A.; Grime, G. W.

1993-05-01

The inorganic analysis of archaeological bone material can potentially provide a wealth of information about the chronology, diet and palaeoenvironment of past populations: for example, strontium and uranium levels are used in palaeodietary and dating studies, respectively. However, the extent to which the chemical composition of bone is subject to diagenetic change during burial is open to controversy due, in part, to differences in analytical technique, bone types and burial conditions. To investigate this problem, archaeological human bone material from a number of different geological environments including Pompeii and a 12th century British ecclesiastical site, together with material from two seawater burials (The "Mary Rose" and a 6th century Mediterranean wreck) have been studied using the nuclear microprobe facility at the University of Oxford. Results using microbeam PIXE show that bone is subject to contamination from a wide range of trace elements depending on the burial conditions. Elemental maps are presented to demonstrate the distribution of trace element accumulation under different burial conditions, and the significance of this work to future trace element studies is discussed.

Ion beam modification of zinc white pigment characterized by ex situ and in situ μ-Raman and XPS

NASA Astrophysics Data System (ADS)

Beck, L.; Gutiérrez, P. C.; Miro, S.; Miserque, F.

2017-10-01

Zinc oxide, known as zinc white, is one of the principal white pigments developed in the 18th century and was used by the Impressionist painters. ZnO as artists' pigment has occasionally been characterized by X-ray and ion beam techniques, but these studies are limited by the potential for visible radiation effect. Ion beam modifications of zinc oxide have extensively been investigated, but mainly for electronic and industrial applications. In this paper, we focus our investigation on ion beam modification of ZnO used as pigment. Two irradiation conditions have been used: an external 3 MeV proton micro-beam representative of PIXE analysis and 2 MeV H+ and 1.2 MeV Au + beams in vacuum to investigate irradiation modifications in electronic and nuclear energy loss regimes. Ion beam modification was characterized by ex situ and in situ micro-Raman spectrometry and XPS. The results shows that IBA of zinc white can be carried out safely in historical paintings with low current and dose.

Gold and electrum jewellery in the strategic area of Gadir in Phoenician period

NASA Astrophysics Data System (ADS)

Ortega-Feliu, I.; Gómez-Tubío, B.; Ontalba Salamanca, M. Á.; Respaldiza, M. Á.; de la Bandera, M. L.; Ovejero Zappino, G.

2007-07-01

A set of ancient gold jewellery was found in Cádiz (formerly Gadir, south Spain) in tombs dated in Phoenician-Archaic period (VII-VI century BC), and nowadays is exhibited in the local Museum. The production of this strategic area is of great interest for the knowledge of the commercial routes along the Mediterranean Sea at that time. Part of this production has already been analyzed by the authors, finding compositional differences and identifying soldering procedures, thanks to the use of the external microbeam. Absolutely non destructive analysis was performed. For this work we have again employed PIXE spectrometry with 2.2 MeV protons from the 3 MV Pelletron accelerator at the CNA to characterize the metallic alloys and the manufacturing techniques. We have found an unusual composition characterized by around 50 wt.% gold, 50 wt.% silver and some copper, which can be identified as ELECTRUM. Few analytical data of this particular kind of alloy are reported in the bibliography. The study of these objects can help to follow the trade of metals in the Phoenician-colonial period.

Comparison of two methods for measuring γ-H2AX nuclear fluorescence as a marker of DNA damage in cultured human cells: applications for microbeam radiation therapy

NASA Astrophysics Data System (ADS)

Anderson, D.; Andrais, B.; Mirzayans, R.; Siegbahn, E. A.; Fallone, B. G.; Warkentin, B.

2013-06-01

Microbeam radiation therapy (MRT) delivers single fractions of very high doses of synchrotron x-rays using arrays of microbeams. In animal experiments, MRT has achieved higher tumour control and less normal tissue toxicity compared to single-fraction broad beam irradiations of much lower dose. The mechanism behind the normal tissue sparing of MRT has yet to be fully explained. An accurate method for evaluating DNA damage, such as the γ-H2AX immunofluorescence assay, will be important for understanding the role of cellular communication in the radiobiological response of normal and cancerous cell types to MRT. We compare two methods of quantifying γ-H2AX nuclear fluorescence for uniformly irradiated cell cultures: manual counting of γ-H2AX foci by eye, and an automated, MATLAB-based fluorescence intensity measurement. We also demonstrate the automated analysis of cell cultures irradiated with an array of microbeams. In addition to offering a relatively high dynamic range of γ-H2AX signal versus irradiation dose ( > 10 Gy), our automated method provides speed, robustness, and objectivity when examining a series of images. Our in-house analysis facilitates the automated extraction of the spatial distribution of the γ-H2AX intensity with respect to the microbeam array — for example, the intensities in the peak (high dose area) and valley (area between two microbeams) regions. The automated analysis is particularly beneficial when processing a large number of samples, as is needed to systematically study the relationship between the numerous dosimetric and geometric parameters involved with MRT (e.g., microbeam width, microbeam spacing, microbeam array dimensions, peak dose, valley dose, and geometric arrangement of multiple arrays) and the resulting DNA damage.

The ionoluminescence apparatus at the LABEC external microbeam facility

NASA Astrophysics Data System (ADS)

Calusi, S.; Colombo, E.; Giuntini, L.; Giudice, A. Lo; Manfredotti, C.; Massi, M.; Pratesi, G.; Vittone, E.

2008-05-01

In this paper, we describe the main features of the ionoluminescence (IL) apparatus recently installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC Laboratory in Firenze. The peculiarity of this IL set-up resides in the fact that the light produced by the ion irradiation of the specimen is collected by a bifurcated optical fiber, so that photons are shunted both to a CCD spectrometer, working in the 200-900 nm wavelength range, and to a photomultiplier (PMT). The accurate focusing of the optical system allows high photon collection efficiency and this results in rapid acquisition of luminescence spectra with low ion currents on luminescent materials; simultaneously, luminescence maps with a spatial resolution of 10 μm can be acquired through the synchronization of PMT photon detection with the position of the scanning focused ion beam. An optical filter with a narrow passband facing the photomultiplier allows chromatic selectivity of the luminescence centres. The IL apparatus is synergistically integrated into the existing set-up for ion beam analyses (IBA). The upgraded system permits simultaneous IL and PIXE/PIGE/BS measurements. With our integrated system, we have been studying raw lapis lazuli samples of different known origins and precious lapis lazuli artworks of the Collezione Medicea of Museum of Natural History, University of Firenze, aiming at characterising their composition and provenance.

Deciphering a removed text on a 16th c. centrepiece: The benefits of using AGLAEMap and AXSIA to process PIXE maps.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lemasson, Quentin; Kotula, Paul; Pichon, Laurent

2015-09-01

In the field of archaeometry, it is not uncommon to be presented with art objects that contain inscriptions, signatures and other writings that are nearly impossible to read. Scanned microbeam PIXE offers an attractive approach to attack this problem, but even then the distribution of characteristic X-rays of the element(s) used in these writings can remain illegible. We show in this paper that two methods were used to reveal the inscription: first the use of a GUPIXWin, TRAUPIXE and AGLAEMap software suite enables to make quantitative analysis of each pixel, to visualize the results and to select X-ray peaks thatmore » could enable to distinguish letters. Then, the Automated eXpert Spectral Image Analysis (AXSIA) program developed at Sandia, which analyzes the x-ray intensity vs. Energy and (X, Y) position “datacubes”, was used to factor the datacube into 1) principle component spectral shapes and 2) the weighting images of these components. The specimen selected for this study was a silver plaque representing a scroll from the so-called “MerkelscheTafelaufsatz,” a centrepiece made by the Nuremberg goldsmith Wenzel Jamnitzer in 1549. X-ray radiography of the plaque shows lines of different silver thicknesses, meaning that a text has been removed. The PIXE analysis used a 3-MeV proton beam focused to 50μm and scanned across the sample on different areas of interest of several cm². This analysis showed major elements of Cu and Ag, and minor elements such as Pb, Au, Hg. X-ray intensity maps were then made by setting windows on the various x-ray peaks but the writing on the centrepiece was not revealed even if the map of Cu after data treatment at AGLAE enabled to distinguish some letters. The AXSIA program enabled to factor two main spectral shapes from the datacube that were quite similar and involved virtually all of the X-rays being generated. Nevertheless, small differences between these factors were observed for the Cu K X-rays, Pb, Bi and Au L X-rays. The plot of the factor with the highest Au signal gave also information on the shape of some letters. The comparison of the results obtained by the two methods shows that they both drastically improve the resolution and contrast of such writings and that each of the method can also bring different information on the composition and thus the techniques used for the writing.« less

Mutational And Structural Studies Of The PixD BLUF Output Signal That Affects Light-Regulated Interactions With PixE

PubMed Central

Yuan, Hua; Dragnea, Vladimira; Wu, Qiong; Gardner, Kevin H.; Bauer, Carl E.

2011-01-01

PixD (Slr1694) is a BLUF (blue-light using FAD) photoreceptor used by the cyanobacterium Synechocystis sp. PCC6803 to control phototaxis toward blue light. In this study we probe the involvement of a conserved Tyr8-Gln50-Met93 triad in promoting an output signal upon blue light excitation of the bound flavin. Analysis of acrylamide quenching of Trp91 fluorescence shows that the side chain of this residue remains partially solvent exposed in both the lit and dark states. Mutational analysis demonstrates that substitution mutations at Tyr8 and Gln50 result in the loss of the photocycle while a mutation of Met93 does not appreciably disturb the formation of the light excited state and only minimally accelerates its decay from 5.7 s to 4.5 s. However, mutations in Tyr8, Gln50 and Met93 disrupt the ability of PixD dimers to interact with PixE to form a higher ordered PixD10-PixE5 complex, which is indicative of a lit conformational state. Solution NMR spectroscopy and X-ray crystallographic analyses confirm that a Tyr8 to Phe mutation is locked in a pseudo light excited state revealing flexible areas in PixD that likely constitute part of an output signal upon light excitation of wild type PixD. PMID:21688827

Performance and Applications of the first HVE 5MV Tandetron{sup TM} at the University of Madrid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mous, D.J.W.; Gottdang, A.; Haitsma, R.G.

2003-08-26

The first HVE Tandetron{sup TM} with a nominal terminal voltage of 5 MV has been put into operation at the Universidad Autonoma de Madrid (Spain) as part of their new IBA facility. The accelerator features a coaxial structure in which the all-solid-state power supply is constructed around the high-energy acceleration tube, thereby avoiding the T-shaped tank that has characterized the HVE Tandetrons{sup TM} so far. The new IBA facility covers a number of different ion beam analysis techniques including ERD using heavy-element time-of-flight, RBS, as well as an external micro-beam for PIXE. During installation, tests have shown a stable terminalmore » voltage of 5.5 MV. The terminal voltage ripple was deduced to be below 6 x 10-6 (RMS) for terminal voltages above 800 kV. Terminal voltage undershoot was measured to be 1.4 x 10-3 for a {approx}1 kW beam at 3 MV and recovered to 1 x 10-4 within 800 ms. IBA experiments that require low energy hydrogen beams are supported by a stable terminal voltage down to 100 kV.« less

PIXE and /μ-PIXE analysis of glazes from terracotta sculptures of the della Robbia workshop

NASA Astrophysics Data System (ADS)

Zucchiatti, Alessandro; Bouquillon, Anne; Giancarlo Lanterna; Lucarelli, Franco; Mandò, Pier Andrea; Prati, Paolo; Salomon, Joseph; Vaccari, Maria Grazia

2002-04-01

A series of PIXE analyses has been performed on glazes from terracotta sculptures of the Italian Renaissance and on reference standards. The problems related to the investigation of such heterogeneous materials are discussed and the experimental uncertainties are evaluated, for each element, from the PIXE analysis of standard glasses. Some examples from artefacts coming from Italian collections are given. This research has been conducted in the framework of the COST-G1 European action.

Combined PIXE and XPS analysis on republican and imperial Roman coins

NASA Astrophysics Data System (ADS)

Daccà, A.; Prati, P.; Zucchiatti, A.; Lucarelli, F.; Mandò, P. A.; Gemme, G.; Parodi, R.; Pera, R.

2000-03-01

A combined PIXE and XPS analysis has been performed on a few Roman coins of the republican and imperial age. The purpose was to investigate via XPS the nature and extent of patina in order to be capable of extracting PIXE data relative to the coins bulk. The inclusion of elements from the surface layer, altered by oxidation and inclusion, is a known source of uncertainty in PIXE analyses of coins, performed to assess the composition and the provenance.

Optimization experiments on a pixe system and its application to the analysis of trace elements in shaji

NASA Astrophysics Data System (ADS)

Yin, Zhongli; Zhang, Shunun; Jiang, Xinzhou; Ma, Changjun; Li, Zhenkun; Hao, Jifang; Zheng, Zhihao; Liu, Zhaoyuan; Liu, Zhengmin; Ma, Shuxun; Yang, Kunshan

1989-04-01

This paper describes briefly the optimization of a PIXE setup. Three proton energies 1.5, 2.0 and 2.5 MeV and four kinds of absorbers BE (132 μm), Be (460 μm), Al (28 μm) and Be plus Mylar (460 μm+600 μm) were used. The minimum detection limits (MDL) of PIXE for these various combinations were computed and compared. PIXE analysis of Shaji was performed as an application. The result shows that the stack absorber of 460 μm Be and 600 μm Mylar films and a 2.0 MeV proton energy are most suitable for PIXE analysis of Shaji. Results of the Shaji analysis are presented. Shaji is one of the common seabuckthoms. The Shaji referred to here belongs to Hippophae rhamnoides L. Subsp. Sinensis Rousi.

Theoretical detection limit of PIXE analysis using 20 MeV proton beams

NASA Astrophysics Data System (ADS)

Ishii, Keizo; Hitomi, Keitaro

2018-02-01

Particle-induced X-ray emission (PIXE) analysis is usually performed using proton beams with energies in the range 2∼3 MeV because at these energies, the detection limit is low. The detection limit of PIXE analysis depends on the X-ray production cross-section, the continuous background of the PIXE spectrum and the experimental parameters such as the beam currents and the solid angle and detector efficiency of X-ray detector. Though the continuous background increases as the projectile energy increases, the cross-section of the X-ray increases as well. Therefore, the detection limit of high energy proton PIXE is not expected to increase significantly. We calculated the cross sections of continuous X-rays produced in several bremsstrahlung processes and estimated the detection limit of a 20 MeV proton PIXE analysis by modelling the Compton tail of the γ-rays produced in the nuclear reactions, and the escape effect on the secondary electron bremsstrahlung. We found that the Compton tail does not affect the detection limit when a thin X-ray detector is used, but the secondary electron bremsstrahlung escape effect does have an impact. We also confirmed that the detection limit of the PIXE analysis, when used with 4 μm polyethylene backing film and an integrated beam current of 1 μC, is 0.4∼2.0 ppm for proton energies in the range 10∼30 MeV and elements with Z = 16-90. This result demonstrates the usefulness of several 10 MeV cyclotrons for performing PIXE analysis. Cyclotrons with these properties are currently installed in positron emission tomography (PET) centers.

Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube x-ray source array

NASA Astrophysics Data System (ADS)

Zhang, Lei; Yuan, Hong; Burk, Laurel M.; Inscoe, Christy R.; Hadsell, Michael J.; Chtcheprov, Pavel; Lee, Yueh Z.; Lu, Jianping; Chang, Sha; Zhou, Otto

2014-03-01

Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based x-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board x-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 µm measured directly from the histology (537 µm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors.

Buckling and postbuckling of size-dependent cracked microbeams based on a modified couple stress theory

NASA Astrophysics Data System (ADS)

Akbarzadeh Khorshidi, M.; Shariati, M.

2017-07-01

The elastic buckling analysis and the static postbuckling response of the Euler-Bernoulli microbeams containing an open edge crack are studied based on a modified couple stress theory. The cracked section is modeled by a massless elastic rotational spring. This model contains a material length scale parameter and can capture the size effect. The von Kármán nonlinearity is applied to display the postbuckling behavior. Analytical solutions of a critical buckling load and the postbuckling response are presented for simply supported cracked microbeams. This parametric study indicates the effects of the crack location, crack severity, and length scale parameter on the buckling and postbuckling behaviors of cracked microbeams.

Ion Beam Analysis for the provenance attribution of lapis lazuli used in glyptic art: The case of the "Collezione Medicea"

NASA Astrophysics Data System (ADS)

Re, Alessandro; Angelici, Debora; Lo Giudice, Alessandro; Corsi, Jacopo; Allegretti, Silvia; Biondi, Alessia Fabiola; Gariani, Gianluca; Calusi, Silvia; Gelli, Nicla; Giuntini, Lorenzo; Massi, Mirko; Taccetti, Francesco; La Torre, Leonardo; Rigato, Valentino; Pratesi, Giovanni

2015-04-01

The first part of this study reports on the wide campaign for the extension of the database of both trace and minor elements concentration in diopside by means of μ-PIXE measurements and of luminescence spectra in diopside and wollastonite by means of μ-IL measurements. Diopside and wollastonite are actually two of the most common lapis lazuli-forming minerals. For this former part of the study, we analysed rocks of known provenance at the microbeam line of the LNL laboratories in Legnaro (PD) of the Istituto Nazionale di Fisica Nucleare (INFN). The latter part of the paper is dedicated to the non-invasive Ion Beam Analyses (IBA) characterisation of six pieces of the "Collezione Medicea". The collection is exhibited at the Museum of Natural History (University of Firenze) and belonged to the Medici family. It includes artworks made of lapis lazuli manufactured in the 16th and 17th centuries but there is not precise information about the provenance of the used raw material. Results on the artworks show, as expected, that the Chilean provenance of the material used for the analysed artworks has to be excluded. Lapis lazuli used for five of the analysed artworks can be ascribed to the Afghan quarry district, while one object cannot be attributed only on the base of diopside and wollastonite analysis.

Chemical speciation using high energy resolution PIXE spectroscopy in the tender X-ray range

NASA Astrophysics Data System (ADS)

Kavčič, Matjaž; Petric, Marko; Vogel-Mikuš, Katarina

2018-02-01

High energy resolution X-ray emission spectroscopy employing wavelength dispersive (WDS) crystal spectrometers can provide energy resolution on the level of core-hole lifetime broadening of the characteristic emission lines. While crystal spectrometers have been traditionally used in combination with electron excitation for major and minor element analysis, they have been rarely considered in proton induced X-ray emission (PIXE) trace element analysis mainly due to low detection efficiency. Compared to the simplest flat crystal WDS spectrometer the efficiency can be improved by employing cylindrically or even spherically curved crystals in combination with position sensitive X-ray detectors. When such spectrometer is coupled to MeV proton excitation, chemical bonding effects are revealed in the high energy resolution spectra yielding opportunity to extend the analytical capabilities of PIXE technique also towards chemical state analysis. In this contribution we will focus on the high energy resolution PIXE (HR-PIXE) spectroscopy in the tender X-ray range performed in our laboratory with our home-built tender X-ray emission spectrometer. Some general properties of high energy resolution PIXE spectroscopy in the tender X-ray range are presented followed by an example of sulfur speciation in biological tissue illustrating the capabilities as well as limitations of HR-PIXE method used for chemical speciation in the tender X-ray range.

Nonlinear analysis of thermally and electrically actuated functionally graded material microbeam.

PubMed

Li, Yingli; Meguid, S A; Fu, Yiming; Xu, Daolin

2014-02-08

In this paper, we provide a unified and self-consistent treatment of a functionally graded material (FGM) microbeam with varying thermal conductivity subjected to non-uniform or uniform temperature field. Specifically, it is our objective to determine the effect of the microscopic size of the beam, the electrostatic gap, the temperature field and material property on the pull-in voltage of the microbeam under different boundary conditions. The non-uniform temperature field is obtained by integrating the steady-state heat conduction equation. The governing equations account for the microbeam size by introducing an internal material length-scale parameter that is based on the modified couple stress theory. Furthermore, it takes into account Casimir and van der Waals forces, and the associated electrostatic force with the first-order fringing field effects. The resulting nonlinear differential equations were converted to a coupled system of algebraic equations using the differential quadrature method. The outcome of our work shows the dramatic effect and dependence of the pull-in voltage of the FGM microbeam upon the temperature field, its gradient for a given boundary condition. Specifically, both uniform and non-uniform thermal loading can actuate the FGM microbeam even without an applied voltage. Our work also reveals that the non-uniform temperature field is more effective than the uniform temperature field in actuating a FGM cantilever-type microbeam. For the clamped-clamped case, care must be taken to account for the effective use of thermal loading in the design of microbeams. It is also observed that uniform thermal loading will lead to a reduction in the pull-in voltage of a FGM microbeam for all the three boundary conditions considered.

Image-guided microbeam irradiation to brain tumour bearing mice using a carbon nanotube X-ray source array

PubMed Central

Zhang, Lei; Yuan, Hong; Burk, Laurel M; Inscoe, Christy R; Hadsell, Michael J; Chtcheprov, Pavel; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

2014-01-01

Microbeam radiation therapy (MRT) is a promising experimental and preclinical radiotherapy method for cancer treatment. Synchrotron based MRT experiments have shown that spatially fractionated microbeam radiation has the unique capability of preferentially eradicating tumour cells while sparing normal tissue in brain tumour bearing animal models. We recently demonstrated the feasibility of generating orthovoltage microbeam radiation with an adjustable microbeam width using a carbon nanotube based X-ray source array. Here we report the preliminary results from our efforts in developing an image guidance procedure for the targeted delivery of the narrow microbeams to the small tumour region in the mouse brain. Magnetic resonance imaging was used for tumour identification, and on-board X-ray radiography was used for imaging of landmarks without contrast agents. The two images were aligned using 2D rigid body image registration to determine the relative position of the tumour with respect to a landmark. The targeting accuracy and consistency were evaluated by first irradiating a group of mice inoculated with U87 human glioma brain tumours using the present protocol and then determining the locations of the microbeam radiation tracks using γ-H2AX immunofluorescence staining. The histology results showed that among 14 mice irradiated, 11 received the prescribed number of microbeams on the targeted tumour, with an average localization accuracy of 454 μm measured directly from the histology (537 μm if measured from the registered histological images). Two mice received one of the three prescribed microbeams on the tumour site. One mouse was excluded from the analysis due to tissue staining errors. PMID:24556798

Investigation of (Ti-Zr-Hf-V-Nb)N Multicomponent Nanostructured Coatings before and after Thermal Annealing by Nuclear Physics Methods of Analysis

NASA Astrophysics Data System (ADS)

Pogrebnjak, A. D.; Beresnev, V. M.; Bondar', A. V.; Kaverin, M. V.; Ponomarev, A. G.

2013-10-01

(Ti-Zr-Hf-V-Nb)N multicomponent nanostructured coatings with thickness of 1.0-1.4 μm synthesized by the method of cathode arc-vapor deposition at temperatures of 250-300°С are investigated by various mutually complementary methods of elemental structural analysis using slow positron beams (SPB), proton microbeam based particle-induced x-ray emission (μ-PIXE), energy-dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM) analyses based on electron micro- and nanobeams, x-ray diffraction (XRD) method of phase structural analysis, and the "a-sin2φ" method of measuring a stressed-strained state (x-ray tensometry). The elemental composition, microstructure, residual stress in nanograins, profiles of defect and atom distributions with depth and over the coating surface in 3D-representation are studied for these coatings, and their phase composition, severely strained state, and composition of coatings before and after annealing at Tann = 600°С for annealing time τ = 30 min are investigated. It is demonstrated that the oxidation resistance of the examined coatings can be significantly increased by high-temperature annealing that leads to the formation of elastic severely strained compression state of the coating. Redistribution of elements and defects, their segregation near the interface boundaries and around grains and subgrains in the process of thermostimulated diffusion, and termination of spinodal segregation without considerable change of the average nanograin size are revealed.

Response of avian embryonic brain to spatially segmented x-ray microbeams.

PubMed

Dilmanian, F A; Morris, G M; Le Duc, G; Huang, X; Ren, B; Bacarian, T; Allen, J C; Kalef-Ezra, J; Orion, I; Rosen, E M; Sandhu, T; Sathé, P; Wu, X Y; Zhong, Z; Shivaprasad, H L

2001-05-01

Duck embryo was studied as a model for assessing the effects of microbeam radiation therapy (MRT) on the human infant brain. Because of the high risk of radiation-induced disruption of the developmental process in the immature brain, conventional wide-beam radiotherapy of brain tumors is seldom carried out in infants under the age of three. Other types of treatment for pediatric brain tumors are frequently ineffective. Recent findings from studies in Grenoble on the brain of suckling rats indicate that MRT could be of benefit for the treatment of early childhood tumors. In our studies, duck embryos were irradiated at 3-4 days prior to hatching. Irradiation was carried out using a single exposure of synchrotron-generated X-rays, either in the form of parallel microplanar beams (microbeams), or as non-segmented broad beam. The individual microplanar beams had a width of 27 microm and height of 11 mm, and a center-to-center spacing of 100 microm. Doses to the exposed areas of embryo brain were 40, 80, 160 and 450 Gy (in-slice dose) for the microbeam, and 6, 12 and 18 Gy for the broad beam. The biological end point employed in the study was ataxia. This neurological symptom of radiation damage to the brain developed within 75 days of hatching. Histopathological analysis of brain tissue did not reveal any radiation induced lesions for microbeam doses of 40-160 Gy (in-slice), although some incidences of ataxia were observed in that dose group. However, severe brain lesions did occur in animals in the 450 Gy microbeam dose groups, and mild lesions in the 18 Gy broad beam dose group. These results indicate that embryonic duck brain has an appreciably higher tolerance to the microbeam modality, as compared to the broad beam modality. When the microbeam dose was normalized to the full volume of the irradiated tissue. i.e., the dose averaged over microbeams and the space between the microbeams, brain tolerance was estimated to be about three times higher to microbeam irradiation as compared with broad beam irradiation.

Micro-PIXE and micro-SR-XRF studies for Romanian archaeological gold identification

NASA Astrophysics Data System (ADS)

Constantinescu, B.

2009-04-01

For gold, trace elements are more significant for provenancing archaeological artifacts than the main components: Platinum Group Elements (PGE), Sn, Te, Sb, Hg, Pb, but also high melting point elements, such as Ta and Nb. Several small fragments of native Carpathian gold were studied using micro-PIXE technique at the AGLAE accelerator, Louvre Museum and at the Legnaro AN2000 microbeam facility, and using SR-XRF at BESSY synchrotron. The goal of the study was to identify the trace elements, especially Sn, Sb and Te. At BESSY, the SR-XRF measurements were performed in air by using a 34 keV beam to excite the characteristic X-lines in Sn-Sb-Te region. We found Sn to be present in placers from Valea Arieşului and Valea Pianului, Sb in primary gold from Zlatna, Ruda-Brad, Valea Morii, Runculeţ-Straja and Pb in primary gold from Brǎdişor-Brad, Zlatna, Runculeţ-Straja, Valea Morii, Muşariu-Brad. Ten native gold nuggets and several fragments of objects coming from Visigothic Pietroasa "The Golden Brood Hen with Its Chickens" hoard were analyzed using micro-PIXE technique at the AGLAE accelerator, Louvre Museum, Paris and at the Legnaro AN2000 microbeam facility. We found Te in primary gold from Brǎdişor-Brad, Muşariu-Brad (different samples from BESSY analyzed ones), and Roşia Montanǎ, Sb in primary gold at Bucium-Izbiţa. For Pietroasa hoard, we found Sn in the Oenochoe cup and small fibula, indicating that alluvial gold - probably from Anatolia (Pactolus river) - was used. We also detected Ta inclusions in the large fibula, indicating that Ural Mountains (the only region where Ta and Au minerals are together) gold was (at least partially) used. A spectacular application to nine Dacian gold bracelets (belonging to National History Museum of Romania) authentication is presented. These bracelets look like spirals and are based on the same artistic idea, are centred around the same theme. The number of spiral varies from 6 to 8. When uncoiled, some bracelets measure 2.30 m and others even 2.80 m. 4 of them weigh 1 kg each. At each end, the bracelets are decorated with 7 palm-leaf like ornaments. There are no two identical bracelets. The plate is continued with a so-called "protoma", a decorative element which looks like the head of an animal (a wolf, a snake or a dog). The Dacian bracelets were measured using XRF technique (Am-241 and Pu-238 sources and a portable Mo X-Ray tube used to control the homogeneity of the alloy for each bracelet). Compositions (Au-Ag-Cu) very similar to Brad region native gold (primary and placers), but different form bracelet to bracelet, were obtained. Differences in homogeneity, especially Cu content, for each bracelet were observed. Traces of Sn and Sb were also detected. Our conclusion: native gold (mainly alluvial - placers) from Brad region, primitive metallurgy (no refined gold).

Focusing giga-electronvolt heavy ions to micrometers at the Institute of Modern Physics.

PubMed

Sheng, Lina; Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Song, Mingtao; Yuan, Youjin; Xiao, Guoqing

2013-05-01

To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiation. Recently, microbeam of (12)C(6+) with energy of 80.55 MeV/u was successfully achieved at this interdisciplinary microbeam facility with a full beam spot size of 3 μm × 5 μm on target in air. Different from ions with energy of several MeV/u, the very high ion energy of hundred MeV/u level induces problems in beam micro-collimation, online beam spot diagnosis, radiation protection, etc. This paper presents the microbeam setup, difficulties in microbeam formation, and the preliminary experiments performed with the facility.

PIXE analysis of caries related trace elements in tooth enamel

NASA Astrophysics Data System (ADS)

Annegarn, H. J.; Jodaikin, A.; Cleaton-Jones, P. E.; Sellschop, J. P. F.; Madiba, C. C. P.; Bibby, D.

1981-03-01

PIXE analysis has been applied to a set of twenty human teeth to determine trace element concentration in enamel from areas susceptible to dental caries (mesial and distal contact points) and in areas less susceptible to the disease (buccal surfaces), with the aim of determining the possible roles of trace elements in the curious process. The samples were caries-free anterior incisors extracted for periodontal reasons from subjects 10-30 years of age. Prior to extraction of the sample teeth, a detailed dental history and examination was carried out in each individual. PIXE analysis, using a 3 MeV proton beam of 1 mm diameter, allowed the determination of Ca, Mn, Fe, Cu, Zn, Sr and Pb above detection limits. As demonstrated in this work, the enhanced sensitivity of PIXE analysis over electron microprobe analysis, and the capability of localised surface analysis compared with the pooled samples required for neutron activation analysis, makes it a powerful and useful technique in dental analysis.

Hydrodynamic Determinants of Cell Necrosis and Molecular Delivery Produced by Pulsed Laser Microbeam Irradiation of Adherent Cells

PubMed Central

Compton, Jonathan L.; Hellman, Amy N.; Venugopalan, Vasan

2013-01-01

Time-resolved imaging, fluorescence microscopy, and hydrodynamic modeling were used to examine cell lysis and molecular delivery produced by picosecond and nanosecond pulsed laser microbeam irradiation in adherent cell cultures. Pulsed laser microbeam radiation at λ = 532 nm was delivered to confluent monolayers of PtK2 cells via a 40×, 0.8 NA microscope objective. Using laser microbeam pulse durations of 180–1100 ps and pulse energies of 0.5–10.5 μJ, we examined the resulting plasma formation and cavitation bubble dynamics that lead to laser-induced cell lysis, necrosis, and molecular delivery. The cavitation bubble dynamics are imaged at times of 0.5 ns to 50 μs after the pulsed laser microbeam irradiation, and fluorescence assays assess the resulting cell viability and molecular delivery of 3 kDa dextran molecules. Reductions in both the threshold laser microbeam pulse energy for plasma formation and the cavitation bubble energy are observed with decreasing pulse duration. These energy reductions provide for increased precision of laser-based cellular manipulation including cell lysis, cell necrosis, and molecular delivery. Hydrodynamic analysis reveals critical values for the shear-stress impulse generated by the cavitation bubble dynamics governs the location and spatial extent of cell necrosis and molecular delivery independent of pulse duration and pulse energy. Specifically, cellular exposure to a shear-stress impulse J≳0.1 Pa s ensures cell lysis or necrosis, whereas exposures in the range of 0.035≲J≲0.1 Pa s preserve cell viability while also enabling molecular delivery of 3 kDa dextran. Exposure to shear-stress impulses of J≲0.035 Pa s leaves the cells unaffected. Hydrodynamic analysis of these data, combined with data from studies of 6 ns microbeam irradiation, demonstrates the primacy of shear-stress impulse in determining cellular outcome resulting from pulsed laser microbeam irradiation spanning a nearly two-orders-of-magnitude range of pulse energy and pulse duration. These results provide a mechanistic foundation and design strategy applicable to a broad range of laser-based cellular manipulation procedures. PMID:24209868

Method and devices for performing stereotactic microbeam radiation therapy

DOEpatents

Dilmanian, F. Avraham

2010-01-05

A radiation delivery system generally includes either a synchrotron source or a support frame and a plurality of microbeam delivery devices supported on the support frame, both to deliver a beam in a hemispherical arrangement. Each of the microbeam delivery devices or synchrotron irradiation ports is adapted to deliver at least one microbeam of radiation along a microbeam delivery axis, wherein the microbeam delivery axes of the plurality of microbeam delivery devices cross within a common target volume.

Focusing giga-electronvolt heavy ions to micrometers at the Institute of Modern Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheng Lina; Du Guanghua; Guo Jinlong

2013-05-15

To study the radiation effect of cosmic heavy ions of low fluxes in electronics and living samples, a focusing heavy ion microbeam facility, for ions with energies of several MeV/u up to 100 MeV/u, was constructed in the Institute of Modern Physics of the Chinese Academy of Sciences. This facility has a vertical design and an experiment platform for both in-vacuum analysis and in-air irradiation. Recently, microbeam of {sup 12}C{sup 6+} with energy of 80.55 MeV/u was successfully achieved at this interdisciplinary microbeam facility with a full beam spot size of 3 {mu}m Multiplication-Sign 5 {mu}m on target in air.more » Different from ions with energy of several MeV/u, the very high ion energy of hundred MeV/u level induces problems in beam micro-collimation, online beam spot diagnosis, radiation protection, etc. This paper presents the microbeam setup, difficulties in microbeam formation, and the preliminary experiments performed with the facility.« less

On the Applications of IBA Techniques to Biological Samples Analysis: PIXE and RBS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Falcon-Gonzalez, J. M.; Bernal-Alvarado, J.; Sosa, M.

2008-08-11

The analytical techniques based on ion beams or IBA techniques give quantitative information on elemental concentration in samples of a wide variety of nature. In this work, we focus on PIXE technique, analyzing thick target biological specimens (TTPIXE), using 3 MeV protons produced by an electrostatic accelerator. A nuclear microprobe was used performing PIXE and RBS simultaneously, in order to solve the uncertainties produced in the absolute PIXE quantifying. The advantages of using both techniques and a nuclear microprobe are discussed. Quantitative results are shown to illustrate the multielemental resolution of the PIXE technique; for this, a blood standard wasmore » used.« less

PIXE study on the provenance of Chinese ancient porcelain

NASA Astrophysics Data System (ADS)

Zhu, D.; Cheng, H. S.; Lin, J. W.; Yang, F. J.

2006-08-01

This paper reports the PIXE study on the provenance of Chinese ancient porcelain made in 7-10th century. The chemical compositions of Jun celadon samples made at Juntai, Linru and Hunyuan kilns, the white-glazed porcelain samples made at Ding, Huangye and Dangyangyu kilns, and the Ru celadon samples made at Qiangliang Temple were measured by external-beam PIXE, and the factor analysis was applied for identifying their provenances. Experimental results show that the porcelain products made at different kilns can be distinguished according to the compositional differences measured by PIXE.

A comparative study of neutron activation analysis and proton-induced X-ray emission analysis for the determination of heavy metals in estuarine sediments

NASA Astrophysics Data System (ADS)

Randle, K.; Al-Jundi, J.; Mamas, C. J. V.; Sokhi, R. S.; Earwaker, L. G.

1993-06-01

Our work on heavy metals in the estuarine environment has involved the use of two multielement techniques: neutron activation analysis (NAA) and proton-induced X-ray emission (PIXE) analysis. As PIXE is essentially a surface analytical technique problems may arise due to sample inhomogeneity and surface roughness. In order to assess the contribution of these effects we have compared the results from PIXE analysis with those from a technique which analyzes a larger bulk sample rather than just the surface. An obvious method was NAA. A series of sediment samples containing particles of variable diameter were compared. Pellets containing a few mg of sediment were prepared from each sample and analyzed by the PIXE technique using both an absolute and a comparitive method. For INAA the rest of the sample was then irradiated with thermal neutrons and element concentrations determined from analyses of the subsequent gamma-ray spectrum. Results from the two methods are discussed.

PIXE analysis of elements in gastric cancer and adjacent mucosa

NASA Astrophysics Data System (ADS)

Liu, Qixin; Zhong, Ming; Zhang, Xiaofeng; Yan, Lingnuo; Xu, Yongling; Ye, Simao

1990-04-01

The elemental regional distributions in 20 resected human stomach tissues were obtained using PIXE analysis. The samples were pathologically divided into four types: normal, adjacent mucosa A, adjacent mucosa B and cancer. The targets for PIXE analysis were prepared by wet digestion with a pressure bomb system. P, K, Fe, Cu, Zn and Se were measured and statistically analysed. We found significantly higher concentrations of P, K, Cu, Zn and a higher ratio of Cu compared to Zn in cancer tissue as compared with normal tissue, but statistically no significant difference between adjacent mucosa and cancer tissue was found.

Pix proteins and the evolution of centrioles.

PubMed

Woodland, Hugh R; Fry, Andrew M

2008-01-01

We have made a wide phylogenetic survey of Pix proteins, which are constituents of vertebrate centrioles in most eukaryotes. We have also surveyed the presence and structure of flagella or cilia and centrioles in these organisms, as far as is possible from published information. We find that Pix proteins are present in a vast range of eukaryotes, but not all. Where centrioles are absent so are Pix proteins. If one considers the maintenance of Pix proteins over evolutionary time scales, our analysis would suggest that their key function is to make cilia and flagella, and the same is true of centrioles. Moreover, this survey raises the possibility that Pix proteins are only maintained to make cilia and flagella that undulate, and even then only when they are constructed by transporting ciliary constituents up the cilium using the intraflagellar transport (IFT) system. We also find that Pix proteins have become generally divergent within Ecdysozoa and between this group and other taxa. This correlates with a simplification of centrioles within Ecdysozoa and a loss or divergence of cilia/flagella. Thus Pix proteins act as a weathervane to indicate changes in centriole function, whose core activity is to make cilia and flagella.

Corrosion of 15th and early 16th century stained glass from the monastery of Batalha studied with external ion beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vilarigues, M., E-mail: mgv@fct.unl.pt; Redol, P.; Monastery of Batalha, P-2440

2011-02-15

This paper reports the study of corrosion in two stained glass panels from the south aisle of Sta. Maria da Vitoria monastery, at Batalha (Portugal), one depicting the Last Supper (dated from 1508), and the other one showing a saint (c. 1450). These panels exhibit extensive corrosion with darkening phenomena that are an impediment to their correct visualization, a source of major concern both to conservators and curators. By using external micro-beam Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma Emission (PIGE) spectrometry, the elemental compositions of large fragments were obtained, enabling the selection of representative corroded areas, frommore » which elemental distribution maps were produced by scanning. Calcium and potassium rich structures were found - at the surface and inside cavities in the glass - that were identified as oxalates and carbonates, by Raman microscopy and micro-FTIR. The dark spots present in the glass surfaces were found to be Zn and Pb rich. These findings indicate that the corrosion observed was due not only to reactions with atmospheric water and CO{sub 2} but also with the oxalic acid secreted by micro-organisms. Furthermore, it did not result from reactions with atmospheric SO{sub 2} or acid rain. The information obtained is relevant for a better understanding of the corrosion processes and products formed on the surface of these panels and therefore for the proper planning of much needed adequate conservation-restoration actions and appropriate display conditions. - Research Highlights: {yields} Corrosion and darkening of stained glasses is of concern to conservators and curators. {yields} A multi-technique approach is of relevance to study stained glass corrosion. {yields} External beam PIXE-PIGE provide valuable insight on stained glass corrosion.« less

Ion, X-ray, UV and Neutron Microbeam Systems for Cell Irradiation.

PubMed

Bigelow, A W; Randers-Pehrson, G; Garty, G; Geard, C R; Xu, Y; Harken, A D; Johnson, G W; Brenner, D J

2010-08-08

The array of microbeam cell-irradiation systems, available to users at the Radiological Research Accelerator Facility (RARAF), Center for Radiological Research, Columbia University, is expanding. The HVE 5MV Singletron particle accelerator at the facility provides particles to two focused ion microbeam lines: the sub-micron microbeam II and the permanent magnetic microbeam (PMM). Both the electrostatic quadrupole lenses on the microbeam II system and the magnetic quadrupole lenses on the PMM system are arranged as compound lenses consisting of two quadrupole triplets with "Russian" symmetry. Also, the RARAF accelerator is a source for a proton-induced x-ray microbeam (undergoing testing) and is projected to supply protons to a neutron microbeam based on the (7)Li(p, n)(7)Be nuclear reaction (under development). Leveraging from the multiphoton microscope technology integrated within the microbeam II endstation, a UV microspot irradiator - based on multiphoton excitation - is available for facility users. Highlights from radiation-biology demonstrations on single living mammalian cells are included in this review of microbeam systems for cell irradiation at RARAF.

PIXE as a complement to ICP-OES trace metal analysis in Sudanese medicinal plants.

PubMed

Mubark Ebrahim, Ammar; Etayeb, M A; Khalid, H; Noun, Manale; Roumie, M; Michalke, B

2014-08-01

This paper compares trace element concentrations (Ca, K, Sr, Fe, Mn, Zn, Ni, Cu, Co and Cr) in 27 Sudanese medical plants determined in parallel by PIXE and ICP-OES to get information on which technique is preferable at different matrices and element concentrations. PIXE correlates well to ICP-OES for Sr, Mn, Ca, K, Zn and Fe determinations. ICP-OES seems to be the superior technique over PIXE when measuring low concentrated elements (chromium, cobalt, nickel and copper) in the medicinal plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Large scale intercomparison of aerosol trace element analysis by different analytical methods

NASA Astrophysics Data System (ADS)

Bombelka, E.; Richter, F.-W.; Ries, H.; Wätjen, U.

1984-04-01

The general agreement of PIXE analysis with other methods (INAA, XRF, AAS, OES-ICP, and PhAA) is very good based on the analysis of filter pieces taken from 250 aerosol samples. It is better than 5% for Pb and Zn, better than 10% for V, Cr, and Mn, indicating that the accuracy of PIXE analysis can be within 10%. For elements such as Cd and Sb, difficult to analyze by PIXE because of their low mass content in the sample, the agreement is given mainly by the reproducibility of the method (20% to 30%). Similar agreement is found for sulfur, after taking account of the depth distribution of the aerosol in the filter.

PIXE analysis of cystic fibrosis sweat samples with an external proton beam

NASA Astrophysics Data System (ADS)

Sommer, F.; Massonnet, B.

1987-03-01

PIXE analysis with an external proton beam is used to study, in four control and five cystic fibrosis children, the elemental composition of sweat samples collected from different parts of the body during entire body hyperthermia. We observe no significant difference of sweat rates and of temperature variations between the two groups during sweat test. The statistical study of results obtained by PIXE analysis allows us to pick out amongst 8 elements studied, 6 elements (Na, Cl, Ca, Mn, Cu, Br) significatively different between the two groups of subjects. Using regression analysis, Na, Cl and Br concentrations could be used in a predictive equation of the state of health.

Vibration analysis of a rotating functionally graded tapered microbeam based on the modified couple stress theory by DQEM

NASA Astrophysics Data System (ADS)

Ghadiri, Majid; Shafiei, Navvab; Alireza Mousavi, S.

2016-09-01

Due to having difficulty in solving governing nonlinear differential equations of a non-uniform microbeam, a few numbers of authors have studied such fields. In the present study, for the first time, the size-dependent vibration behavior of a rotating functionally graded (FG) tapered microbeam based on the modified couple stress theory is investigated using differential quadrature element method (DQEM). It is assumed that physical and mechanical properties of the FG microbeam are varying along the thickness that will be defined as a power law equation. The governing equations are determined using Hamilton's principle, and DQEM is presented to obtain the results for cantilever and propped cantilever boundary conditions. The accuracy and validity of the results are shown in several numerical examples. In order to display the influence of size on the first two natural frequencies and consequently changing of some important microbeam parameters such as material length scale, rate of cross section, angular velocity and gradient index of the FG material, several diagrams and tables are represented. The results of this article can be used in designing and optimizing elastic and rotary-type micro-electro-mechanical systems like micro-motors and micro-robots including rotating parts.

Scanning transmission ion microscopy mass measurements for quantitative trace element analysis within biological samples and validation using atomic force microscopy thickness measurements

NASA Astrophysics Data System (ADS)

Devès, Guillaume; Cohen-Bouhacina, Touria; Ortega, Richard

2004-10-01

We used the nuclear microprobe techniques, micro-PIXE (particle-induced X-ray emission), micro-RBS (Rutherford backscattering spectrometry) and scanning transmission ion microscopy (STIM) in order to perform the characterization of trace element content and spatial distribution within biological samples (dehydrated cultured cells, tissues). The normalization of PIXE results was usually expressed in terms of sample dry mass as determined by micro-RBS recorded simultaneously to micro-PIXE. However, the main limit of RBS mass measurement is the sample mass loss occurring during irradiation and which could be up to 30% of the initial sample mass. We present here a new methodology for PIXE normalization and quantitative analysis of trace element within biological samples based on dry mass measurement performed by mean of STIM. The validation of STIM cell mass measurements was obtained in comparison with AFM sample thickness measurements. Results indicated the reliability of STIM mass measurement performed on biological samples and suggested that STIM should be performed for PIXE normalization. Further information deriving from direct confrontation of AFM and STIM analysis could as well be obtained, like in situ measurements of cell specific gravity within cells compartment (nucleolus and cytoplasm).

THE MULTIELEMENTAL ANALYSIS OF DRINKING WATER USING PROTON-INDUCED X-RAY EMISSION (PIXE)

EPA Science Inventory

A new, rapid, and economical method for the multielemental analysis of drinking water samples is described. The concentrations of 76 elements heavier than aluminum are determined using proton-induced x-ray emission (PIXE) technology. The concentration of sodium is evaluated using...

Focus small to find big - the microbeam story.

PubMed

Wu, Jinhua; Hei, Tom K

2017-08-29

Even though the first ultraviolet microbeam was described by S. Tschachotin back in 1912, the development of sophisticated micro-irradiation facilities only began to flourish in the late 1980s. In this article, we highlight significant microbeam experiments, describe the latest microbeam irradiator configurations and critical discoveries made by using the microbeam apparatus. Modern radiological microbeams facilities are capable of producing a beam size of a few micrometers, or even tens of nanometers in size, and can deposit radiation with high precision within a cellular target. In the past three decades, a variety of microbeams has been developed to deliver a range of radiations including charged particles, X-rays, and electrons. Despite the original intention for their development to measure the effects of a single radiation track, the ability to target radiation with microbeams at sub-cellular targets has been extensively used to investigate radiation-induced biological responses within cells. Studies conducted using microbeams to target specific cells in a tissue have elucidated bystander responses, and further studies have shown reactive oxygen species (ROS) and reactive nitrogen species (RNS) play critical roles in the process. The radiation-induced abscopal effect, which has a profound impact on cancer radiotherapy, further reaffirmed the importance of bystander effects. Finally, by targeting sub-cellular compartments with a microbeam, we have reported cytoplasmic-specific biological responses. Despite the common dogma that nuclear DNA is the primary target for radiation-induced cell death and carcinogenesis, studies conducted using microbeam suggested that targeted cytoplasmic irradiation induces mitochondrial dysfunction, cellular stress, and genomic instability. A more recent development in microbeam technology includes application of mouse models to visualize in vivo DNA double-strand breaks. Microbeams are making important contributions towards our understanding of radiation responses in cells and tissue models.

PIXE analysis of historical paintings: Is the gain worth the risk?

NASA Astrophysics Data System (ADS)

Calligaro, T.; Gonzalez, V.; Pichon, L.

2015-11-01

The PIXE analysis of easel paintings constitutes a challenging task. Despite recognized merits and a few emblematic applications, PIXE has never been routinely applied to these fragile, complex and precious targets. The present work discusses the place of PIXE in the study of easel paintings and opens up perspectives for a more systematic usage of this analytical technique. Progress achieved since decades in the implementation of PIXE to study such fragile cultural heritage artefacts is reviewed, notably at the LABEC laboratory in Italy and at the AGLAE facility of the C2RMF in France. Two specific techniques developed for paintings are detailed and exemplified on Renaissance painting masterpieces: differential PIXE for paint layers depth profiling and multi-scale elemental mapping for the imaging of pigment distribution. Beam-induced damage, a major concern, notably depends on the employed beam fluence in particle/cm2 or μC/cm2. After recalling previous works on damage induced in chemical products comparable to pigments, we present the behaviour under different fluences of protons of a few MeV (1-300 μC/cm2) of targets having high resemblance to historical easel paintings: pellets of specially synthesized lead white pigments, layers of lead white mixed with linseed oil and areas containing lead white of two 19th century paintworks. The results shed new lights on the behaviour of paintworks under the beam and pave the way to strategies for damage mitigation. In particular, the lowering of PIXE performance induced by the decrease of the beam fluence sets a trade-off between risk of damage and gained information which also impacts the PIXE scanning protocol for paintings. As an illustration of an adequate adjustment of this balance, we report the exploratory application of PIXE mapping to a large area of a 19th century easel painting without damage. The recorded elemental maps are compared to elemental maps collected on the same area using laboratory-based scanning XRF.

Detection of halogenated flame retardants in polyurethane foam by particle induced X-ray emission

NASA Astrophysics Data System (ADS)

Maley, Adam M.; Falk, Kyle A.; Hoover, Luke; Earlywine, Elly B.; Seymour, Michael D.; DeYoung, Paul A.; Blum, Arlene; Stapleton, Heather M.; Peaslee, Graham F.

2015-09-01

A novel application of particle-induced X-ray emission (PIXE) has been developed to detect the presence of chlorinated and brominated flame retardant chemicals in polyurethane foams. Traditional Gas Chromatography-Mass Spectrometry (GC-MS) methods for the detection and identification of halogenated flame retardants in foams require extensive sample preparation and data acquisition time. The elemental analysis of the halogens in polyurethane foam performed by PIXE offers the opportunity to identify the presence of halogenated flame retardants in a fraction of the time and sample preparation cost. Through comparative GC-MS and PIXE analysis of 215 foam samples, excellent agreement between the two methods was obtained. These results suggest that PIXE could be an ideal rapid screening method for the presence of chlorinated and brominated flame retardants in polyurethane foams.

A comparison of the techniques of PIXE, PIGE and INAA by reference to the elemental analysis of porcine brain samples

NASA Astrophysics Data System (ADS)

Stedman, J. D.; Spyrou, N. M.

1994-12-01

The trace element concentrations in porcine brain samples as determined by particle-induced X-ray emission (PIXE) analysis, instrumental neutron activation analysis (INAA) and particle-induced gamma-ray emission (PIGE) analysis are compared. The matrix composition was determined by Rutherford backscattering (RBS). Al, Si, P, S, Cl, K, Ca, Mn, Fe and Cd were determined by PIXE analysis Na, K, Sc, Fe, Co, Zn, As, Br, Rb, and Cs by INAA and Na, Mg and Fe by PIGE analysis. The bulk elements C, N, O, Na Cl and S were found by RBS analysis. Elemental concentrations are obtained using the comparator method of analysis rather than an absolute method, the validity which is examined by comparing the elemental concentrations obtained in porcine brain using two separate certified reference materials.

Non-destructive analysis and appraisal of ancient Chinese porcelain by PIXE

NASA Astrophysics Data System (ADS)

Cheng, H. S.; Zhang, Z. Q.; Xia, H. N.; Jiang, J. C.; Yang, F. J.

2002-05-01

This paper reports the results of the PIXE analysis on ancient Chinese blue and white porcelain fired at Kuan Kiln (Jingdezhen, Jiangxi province) during 13-19th century. The major, minor and trace element of porcelain body, white glaze and blue glaze were determined by PIXE. In this paper the chemical compositions of porcelain body, white glaze and blue glaze measured from Yuan (AD 1206-1368), Ming (AD 1368-1644) and Qing (AD 1616-1911) blue and white porcelain are present. The cobalt blue pigment used in Yuan, Ming and Qing are also discussed.

CdTe and EDS HR-PIXE Ta L and M spectra induced by duoplasmatron generated proton and oxygen ion beams

NASA Astrophysics Data System (ADS)

Reis, M. A.; Chaves, P. C.

2018-02-01

Particle induced X-ray emission (PIXE) is a powerful technique for quantitative analysis because it is non-destructive, multi-elemental (from Na to U), highly sensitive and requires no special sample preparation. Heavy Ions PIXE (HI-PIXE), may represent a further step in versatility but it comes with added complexity of the physical processes involved in X-ray production, which require among other things new software capabilities. In this work, the specific capacities of the DT2 code are used to simulate and fit Ta L- and M-shell spectra obtained during the irradiation of a Ta2O5 thin film deposited upon a polished vitreous graphite substrate, produced in the frame of the Heavy Ions PIXE workpakage of the IAEA Coordinated Research Project F11019 on analytical uses of MeV focused ion beams. Proton and oxygen beams from a duoplasmatron ion source were used, and spectra were collected using both the CdTe and the X-ray Microcalorimeter Spectrometer detectors of the High Resolution High X-ray Energy PIXE (HRHE-PIXE) facility of C2TN. Results obtained from the simulation and the fitting of these spectra are presented and discussed.

Elemental analysis with external-beam PIXE

NASA Astrophysics Data System (ADS)

Lin, E. K.; Wang, C. W.; Teng, P. K.; Huang, Y. M.; Chen, C. Y.

1992-05-01

A beamline system and experimental setup has been established for elemental analysis using PIXE with an external beam. Experiments for the study of the elemental composition of ancient Chinese potsherds (the Min and Ching ages) were performed. Continuum X-ray spectra from the samples bombarded by 3 MeV protons have been measured with a Si(Li) detector. From the analysis of PIXE data, the concentration of the main elements (Al, Si, K, and Ca) and of more than ten trace elements in the matrices and glazed surfaces were determined. Results for two different potsherds are presented, and those obtained from the glaze colorants are compared with the results of measurements on a Ching blue-and-white porcelain vase.

PIXE Analysis of Atmospheric Aerosol Samples Collected in the Adirondack Mountains

NASA Astrophysics Data System (ADS)

Yoskowitz, Josh; Ali, Salina; Nadareski, Benjamin; Safiq, Alexandrea; Smith, Jeremy; Labrake, Scott; Vineyard, Michael

2013-10-01

We have performed an elemental analysis of atmospheric aerosol samples collected at Piseco Lake in Upstate New York using proton induced x-ray emission spectroscopy (PIXE). This work is part of a systematic study of airborne pollution in the Adirondack Mountains. Of particular interest is the sulfur content that can contribute to acid rain, a well-documented problem in the Adirondacks. We used a nine-stage cascade impactor to collect the samples and distribute the particulate matter onto Kapton foils by particle size. The PIXE experiments were performed with 2.2-MeV proton beams from the 1.1-MV pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. X-Ray energy spectra were measured with a silicon drift detector and analyzed with GUPIX software to determine the elemental concentrations of the aerosols. A broad range of elements from silicon to zinc were detected with significant sulfur concentrations measured for particulate matter between 0.25 and 0.5 μm in size. The PIXE analysis will be described and preliminary results will be presented.

Artificial neural networks applied to quantitative elemental analysis of organic material using PIXE

NASA Astrophysics Data System (ADS)

Correa, R.; Chesta, M. A.; Morales, J. R.; Dinator, M. I.; Requena, I.; Vila, I.

2006-08-01

An artificial neural network (ANN) has been trained with real-sample PIXE (particle X-ray induced emission) spectra of organic substances. Following the training stage ANN was applied to a subset of similar samples thus obtaining the elemental concentrations in muscle, liver and gills of Cyprinus carpio. Concentrations obtained with the ANN method are in full agreement with results from one standard analytical procedure, showing the high potentiality of ANN in PIXE quantitative analyses.

Silicon Drift Detector response function for PIXE spectra fitting

NASA Astrophysics Data System (ADS)

Calzolai, G.; Tapinassi, S.; Chiari, M.; Giannoni, M.; Nava, S.; Pazzi, G.; Lucarelli, F.

2018-02-01

The correct determination of the X-ray peak areas in PIXE spectra by fitting with a computer program depends crucially on accurate parameterization of the detector peak response function. In the Guelph PIXE software package, GUPIXWin, one of the most used PIXE spectra analysis code, the response of a semiconductor detector to monochromatic X-ray radiation is described by a linear combination of several analytical functions: a Gaussian profile for the X-ray line itself, and additional tail contributions (exponential tails and step functions) on the low-energy side of the X-ray line to describe incomplete charge collection effects. The literature on the spectral response of silicon X-ray detectors for PIXE applications is rather scarce, in particular data for Silicon Drift Detectors (SDD) and for a large range of X-ray energies are missing. Using a set of analytical functions, the SDD response functions were satisfactorily reproduced for the X-ray energy range 1-15 keV. The behaviour of the parameters involved in the SDD tailing functions with X-ray energy is described by simple polynomial functions, which permit an easy implementation in PIXE spectra fitting codes.

Method for microbeam radiation therapy

DOEpatents

Slatkin, Daniel N.; Dilmanian, F. Avraham; Spanne, Per O.

1994-01-01

A method of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation, in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue.

Method for microbeam radiation therapy

DOEpatents

Slatkin, D.N.; Dilmanian, F.A.; Spanne, P.O.

1994-08-16

A method is disclosed of performing radiation therapy on a patient, involving exposing a target, usually a tumor, to a therapeutic dose of high energy electromagnetic radiation, preferably X-ray radiation. The dose is in the form of at least two non-overlapping microbeams of radiation, each microbeam having a width of less than about 1 millimeter. Target tissue exposed to the microbeams receives a radiation dose during the exposure that exceeds the maximum dose that such tissue can survive. Non-target tissue between the microbeams receives a dose of radiation below the threshold amount of radiation that can be survived by the tissue, and thereby permits the non-target tissue to regenerate. The microbeams may be directed at the target from one direction, or from more than one direction in which case the microbeams overlap within the target tissue enhancing the lethal effect of the irradiation while sparing the surrounding healthy tissue. No Drawings

Measuring mercury and other elemental components in tree rings

USGS Publications Warehouse

Gillan, C.; Hollerman, W.A.; Doyle, T.W.; Lewis, T.E.

2004-01-01

There has been considerable interest in measuring heavy metal pollution, such as mercury, using tree ring analysis. Since 1970, this method has provided a historical snapshot of pollutant concentrations near hazardous waste sites. Traditional methods of analysis have long been used with heavy metal pollutants such as mercury. These methods, such as atomic fluorescence and laser ablation, are sometimes time consuming and expensive to implement. In recent years, ion beam techniques, such as Particle Induced X-Ray Emission (PIXE), have been used to measure large numbers of elements. Most of the existing research in this area has been completed for low to medium atomic number pollutants, such as titanium, cobalt, nickel, and copper. Due to the reduction of sensitivity, it is often difficult or impossible to use traditional low energy (few MeV) PIXE analysis for pollutants with large atomic numbers. For example, the PIXE detection limit for mercury was recently measured to be about 1 ppm for a spiked Southern Magnolia wood sample [ref. 1]. This presentation will compare PIXE and standard chemical concentration results for a variety of wood samples.

Measuring mercury and other elemental components in tree rings

USGS Publications Warehouse

Gillan, C.; Hollerman, W.A.; Doyle, T.W.; Lewis, T.E.

2004-01-01

There has been considerable interest in measuring heavy metal pollution, such as mercury, using tree ring analysis. Since 1970, this method has provided a historical snapshot of pollutant concentrations near hazardous waste sites. Traditional methods of analysis have long been used with heavy metal pollutants such as mercury. These methods, such as atomic fluorescence and laser ablation, are sometimes time consuming and expensive to implement. In recent years, ion beam techniques, such as Particle Induced X-Ray Emission (PIXE), have been used to measure large numbers of elements. Most of the existing research in this area has been completed for low to medium atomic number pollutants, such as titanium, cobalt, nickel, and copper. Due to the reduction of sensitivity, it is often difficult or impossible to use traditional low energy (few MeV) PIXE analysis for pollutants with large atomic numbers. For example, the PIXE detection limit for mercury was recently measured to be about 1 ppm for a spiked Southern Magnolia wood sample [ref. 1]. This presentation will compare PIXE and standard chemical concentration results for a variety of wood samples. Copyright 2004 by ISA.

Effects of geometric nonlinearity in an adhered microbeam for measuring the work of adhesion

NASA Astrophysics Data System (ADS)

Fang, Wenqiang; Mok, Joyce; Kesari, Haneesh

2018-03-01

Design against adhesion in microelectromechanical devices is predicated on the ability to quantify this phenomenon in microsystems. Previous research related the work of adhesion for an adhered microbeam to the beam's unadhered length, and as such, interferometric techniques were developed to measure that length. We propose a new vibration-based technique that can be easily implemented with existing atomic force microscopy tools or similar metrology systems. To make such a technique feasible, we analysed a model of the adhered microbeam using the nonlinear beam theory put forth by Woinowsky-Krieger. We found a new relation between the work of adhesion and the unadhered length; this relation is more accurate than the one by Mastrangelo & Hsu (Mastrangelo & Hsu 1993 J. Microelectromech. S., 2, 44-55. (doi:10.1109/84.232594)) which is commonly used. Then, we derived a closed-form approximate relationship between the microbeam's natural frequency and its unadhered length. Results obtained from this analytical formulation are in good agreement with numerical results from three-dimensional nonlinear finite-element analysis.

External-PIXE analysis for the study of pigments from a painting from the Museum of Contemporary Art

NASA Astrophysics Data System (ADS)

Rizzutto, M. A.; Moro, M. V.; Silva, T. F.; Trindade, G. F.; Added, N.; Tabacniks, M. H.; Kajiya, E. M.; Campos, P. H. V.; Magalhães, A. G.; Barbosa, M.

2014-08-01

External Ion Beam Analysis is a useful tool for the characterization of cultural heritage objects. During the last decade, several significant collaborations have been established between Ion Beam Analysis (IBA) scientists and art or archeology professionals, demanding in-air IBA for a variety of different cultural heritage objects. In-air Particle Induced X-ray Emission (PIXE) analyses of an oil painting by the Italian painter, Mario Sironi, from the Museum of Contemporary Art of the University of São Paulo (MAC-USP), were examined. This painting is particularly interesting due to paintings on both sides (oil on canvas on the front and oil on wood on the back side). PIXE analysis helped the identification of the pigment similarities on both sides of the painting, suggesting the same authorship.

betaPIX controls cell motility and neurite extension by regulating the distribution of GIT1.

PubMed

Za, Lorena; Albertinazzi, Chiara; Paris, Simona; Gagliani, Mariacristina; Tacchetti, Carlo; de Curtis, Ivan

2006-07-01

Cell motility entails the reorganization of the cytoskeleton and membrane trafficking for effective protrusion. GIT1/p95-APP1 is a member of a family of GTPase-activating proteins for ARF GTPases that affect endocytosis, adhesion and migration. GIT1 associates with paxillin and a complex including the Rac/Cdc42 exchanging factors PIX/Cool and the kinase PAK. In this study, we show that overexpression of betaPIX induces the accumulation of endogenous and overexpressed GIT1 at large structures similar to those induced by an ArfGAP-defective mutant of GIT1 (p95-C2). Immunohistochemical analysis and immunoelectron microscopy reveal that these structures include the endogenous transferrin receptor. Time-lapse analysis during motogenic stimuli shows that the formation and perinuclear accumulation of the p95-C2-positive structures is paralleled by inhibition of lamellipodium formation and cell retraction. Both dimerization and a functional SH3 domain of betaPIX are required for the accumulation of GIT1 in fibroblasts, which is prevented by the monomeric PIX-PG-DeltaLZ. This mutant also prevents the formation of endocytic aggregates and inhibition of neurite outgrowth in retinal neurons expressing p95-C2. Our results indicate that betaPIX is an important regulator of the subcellular distribution of GIT1, and suggest that alteration in the level of expression of the complex affects the endocytic compartment and cell motility.

In-air PIXE analysis by means of glass capillary optics

NASA Astrophysics Data System (ADS)

Nebiki, Takuya; Kabir, M. Hasnat; Narusawa, Tadashi

2006-08-01

A novel technique to introduce high energy ion beams to atmospheric environment is presented, which enables in-air PIXE measurements. Slightly tapered glass capillary optics is applied to work as a differential pumping orifice as well as a focusing lens. The flux intensity is enhanced by at least one order of magnitude due to the focusing effect. Using capillaries of 10-20 μm outlet diameters, we obtain several hundreds pA of 4 MeV He2+ ion beam and apply it to PIXE analysis of the seabed sludge without any sample treatments. A comparison of spectra between wet and dry sludge samples suggests the usefulness of our new technique.

7th International Workshop on Microbeam Probes of Cellular Radiation Response

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brenner, David J.

2009-07-21

The extended abstracts that follow present a summary of the Proceedings of the 7th International Workshop: Microbeam Probes of Cellular Radiation Response, held at Columbia University’s Kellogg Center in New York City on March 15–17, 2006. These International Workshops on Microbeam Probes of Cellular Radiation Response have been held regularly since 1993 (1–5). Since the first workshop, there has been a rapid growth (see Fig. 1) in the number of centers developing microbeams for radiobiological research, and worldwide there are currently about 30 microbeams in operation or under development. Single-cell/single-particle microbeam systems can deliver beams of different ionizing radiations withmore » a spatial resolution of a few micrometers down to a few tenths of a micrometer. Microbeams can be used to addressquestions relating to the effects of low doses of radiation (a single radiation track traversing a cell or group of cells), to probe subcellular targets (e.g. nucleus or cytoplasm), and to address questions regarding the propagation of information about DNA damage (for example, the radiation-induced bystander effect). Much of the recent research using microbeams has been to study low-dose effects and ‘‘non-targeted’’ responses such as bystander effects, genomic instability and adaptive responses. This Workshop provided a forum to assess the current state of microbeam technology and current biological applications and to discuss future directions for development, both technological and biological. Over 100 participants reviewed the current state of microbeam research worldwide and reported on new technological developments in the fields of both physics and biology.« less

Testing the stand-alone microbeam at Columbia University.

PubMed

Garty, G; Ross, G J; Bigelow, A W; Randers-Pehrson, G; Brenner, D J

2006-01-01

The stand-alone microbeam at Columbia University presents a novel approach to biological microbeam irradiation studies. Foregoing a conventional accelerator as a source of energetic ions, a small, high-specific-activity, alpha emitter is used. Alpha particles emitted from this source are focused using a compound magnetic lens consisting of 24 permanent magnets arranged in two quadrupole triplets. Using a 'home made' 6.5 mCi polonium source, a 1 alpha particle s(-1), 10 microm diameter microbeam can, in principle, be realised. As the alpha source energy is constant, once the microbeam has been set up, no further adjustments are necessary apart from a periodic replacement of the source. The use of permanent magnets eliminates the need for bulky power supplies and cooling systems required by other types of ion lenses and greatly simplifies operation. It also makes the microbeam simple and cheap enough to be realised in any large lab. The Microbeam design as well as first tests of its performance, using an accelerator-based beam are presented here.

PIXE Analysis of Aerosol and Soil Samples Collected in the Adirondack Mountains

NASA Astrophysics Data System (ADS)

Yoskowitz, Joshua; Ali, Salina; Nadareski, Benjamin; Labrake, Scott; Vineyard, Michael

2014-09-01

We have performed an elemental analysis of aerosol and soil samples collected at Piseco Lake in Upstate New York using proton induced X-ray emission spectroscopy (PIXE). This work is part of a systematic study of airborne pollution in the Adirondack Mountains. Of particular interest is the sulfur content that can contribute to acid rain, a well-documented problem in the Adirondacks. We used a nine-stage cascade impactor to collect the aerosol samples near Piseco Lake and distribute the particulate matter onto Kapton foils by particle size. The soil samples were also collected at Piseco Lake and pressed into cylindrical pellets for experimentation. PIXE analysis of the aerosol and soil samples were performed with 2.2-MeV proton beams from the 1.1-MV Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. There are higher concentrations of sulfur at smaller particle sizes (0.25-1 μm), suggesting that it could be suspended in the air for days and originate from sources very far away. Other elements with significant concentrations peak at larger particle sizes (1-4 μm) and are found in the soil samples, suggesting that these elements could originate in the soil. The PIXE analysis will be described and the resulting data will be presented.

PREFACE: European Microbeam Analysis Society's 14th European Workshop on Modern Developments and Applications in Microbeam Analysis (EMAS 2015), Portorož, Slovenia, 3-7 May 2015

NASA Astrophysics Data System (ADS)

Llovet, Xavier; Matthews, Michael B.; Čeh, Miran; Langer, Enrico; Žagar, Kristina

2016-02-01

This volume of the IOP Conference Series: Materials Science and Engineering contains papers from the 14th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from the 3rd to the 7th of May 2015 in the Grand Hotel Bernardin, Portorož, Slovenia. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a unique format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field.This workshop was organized in collaboration with the Jožef Stefan Institute and SDM - Slovene Society for Microscopy. The technical programme included the following topics: electron probe microanalysis, STEM and EELS, materials applications, cathodoluminescence and electron backscatter diffraction (EBSD), and their applications. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2016 Microscopy and Microanalysis meeting at Columbus, Ohio. The prize went to Shirin Kaboli, of the Department of Metals and Materials Engineering of McGill University (Montréal, Canada), for her talk entitled "Electron channelling contrast reconstruction with electron backscattered diffraction". The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 71 posters from 16 countries were on display at the meeting and that the participants came from as far away as Japan, Canada, USA, and Australia. A selection of participants with posters was invited to give a short oral presentation of their work in three dedicated sessions. The prize for the best poster was an invitation to participate in the 24th Australian Conference on Microscopy and Microanalysis (ACMM 24) in Melbourne, Australia. The prize was awarded to Aurélien Moy of the University of Montpellier (France) for his poster entitled: "Standardless quantification of heavy metals by electron probe microanalysis". This proceedings volume contains the full texts of 9 of the invited plenary lectures and of 12 papers on related topics originating from the posters presented at the workshop. All the papers have been subjected to peer review by a least two referees.

Separation of detector non-linearity issues and multiple ionization satellites in alpha-particle PIXE

NASA Astrophysics Data System (ADS)

Campbell, John L.; Ganly, Brianna; Heirwegh, Christopher M.; Maxwell, John A.

2018-01-01

Multiple ionization satellites are prominent features in X-ray spectra induced by MeV energy alpha particles. It follows that the accuracy of PIXE analysis using alpha particles can be improved if these features are explicitly incorporated in the peak model description when fitting the spectra with GUPIX or other codes for least-squares fitting PIXE spectra and extracting element concentrations. A method for this incorporation is described and is tested using spectra recorded on Mars by the Curiosity rover's alpha particle X-ray spectrometer. These spectra are induced by both PIXE and X-ray fluorescence, resulting in a spectral energy range from ∼1 to ∼25 keV. This range is valuable in determining the energy-channel calibration, which departs from linearity at low X-ray energies. It makes it possible to separate the effects of the satellites from an instrumental non-linearity component. The quality of least-squares spectrum fits is significantly improved, raising the level of confidence in analytical results from alpha-induced PIXE.

Pixe analysis of trace elements in tissues of rats treated with anticonvulsants

NASA Astrophysics Data System (ADS)

Hurd, R. W.; Van Rinsvelt, H. A.; Kinyua, A. M.; O'Neill, M. P.; Wilder, B. J.; Houdayer, A.; Hinrichsen, P. F.

1987-04-01

Several lines of evidence implicate metals in epilepsy. Anticonvulsant drugs are noted to alter levels of metals in humans and animals. PIXE analysis was used to investigate effects of three anticonvulsant drugs on tissue and brain cortex trace elements. The content of zinc and copper was increased in liver and spleen of rats treated with anticonvulsants while selenium was decreased in cortex.

Nickel biopathways in tropical nickel hyperaccumulating trees from Sabah (Malaysia)

NASA Astrophysics Data System (ADS)

van der Ent, Antony; Callahan, Damien L.; Noller, Barry N.; Mesjasz-Przybylowicz, Jolanta; Przybylowicz, Wojciech J.; Barnabas, Alban; Harris, Hugh H.

2017-02-01

The extraordinary level of accumulation of nickel (Ni) in hyperaccumulator plants is a consequence of specific metal sequestering and transport mechanisms, and knowledge of these processes is critical for advancing an understanding of transition element metabolic regulation in these plants. The Ni biopathways were elucidated in three plant species, Phyllanthus balgooyi, Phyllanthus securinegioides (Phyllanthaceae) and Rinorea bengalensis (Violaceae), that occur in Sabah (Malaysia) on the Island of Borneo. This study showed that Ni is mainly concentrated in the phloem in roots and stems (up to 16.9% Ni in phloem sap in Phyllanthus balgooyi) in all three species. However, the species differ in their leaves - in P. balgooyi the highest Ni concentration is in the phloem, but in P. securinegioides and R. bengalensis in the epidermis and in the spongy mesophyll (R. bengalensis). The chemical speciation of Ni2+ does not substantially differ between the species nor between the plant tissues and transport fluids, and is unambiguously associated with citrate. This study combines ion microbeam (PIXE and RBS) and metabolomics techniques (GC-MS, LC-MS) with synchrotron methods (XAS) to overcome the drawbacks of the individual techniques to quantitatively determine Ni distribution and Ni2+ chemical speciation in hyperaccumulator plants.

Characterization of compositional modifications in metal-organic frameworks using carbon and alpha particle microbeams

NASA Astrophysics Data System (ADS)

Paneta, V.; Fluch, U.; Petersson, P.; Ott, S.; Primetzhofer, D.

2017-08-01

Zirconium-oxide based metal-organic frameworks (MOFs) were grown on p-type Si wafers. A modified linker molecule containing iodine was introduced by post synthetic exchange (PSE). Samples have been studied using Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE) techniques, employing the 5 MV 15SDH-2 Pelletron Tandem accelerator at the Ångström laboratory. The degree of post synthetic uptake of the iodine-containing linker has been investigated with both a broad beam and a focused beam of carbon and alpha particles targeting different kind of MOF crystals which were of ∼1-10 μm in size, depending on the linker used. Iodine concentrations in MOF crystallites were also measured by Nuclear Magnetic Resonance Spectroscopy (NMR) and are compared to the RBS results. In parallel to the ion beam studies, samples were investigated by Scanning Electron Microscopy (SEM) to quantify possible crystallite clustering, develop optimum sample preparation routines and to characterize the potential ion beam induced sample damage and its dependence on different parameters. Based on these results the reliability and accuracy of ion beam data is assessed.

PIXE Analysis of Indoor Aerosols

NASA Astrophysics Data System (ADS)

Johnson, Christopher; Turley, Colin; Moore, Robert; Battaglia, Maria; Labrake, Scott; Vineyard, Michael

2011-10-01

We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol samples collected in academic buildings at Union College to investigate the air quality in these buildings and the effectiveness of their air filtration systems. This is also the commissioning experiment for a new scattering chamber in the Union College Ion-Beam Analysis Laboratory. The aerosol samples were collected on Kapton foils using a nine-stage cascade impactor that separates particles according to their aerodynamic size. The foils were bombarded with beams of 2.2-MeV protons from the Union College 1.1-MV Pelletron Accelerator and the X-ray products were detected with an Amptek silicon drift detector. After subtracting the contribution from the Kapton foils, the X-ray energy spectra of the aerosol samples were analyzed using GUPIX software to determine the elemental concentrations of the samples. We will describe the collection of the aerosol samples, discuss the PIXE analysis, and present the results.

A Molecularly Imprinted Polymer (MIP)-Coated Microbeam MEMS Sensor for Chemical Detection

DTIC Science & Technology

2015-09-01

ARL-RP-0536 ● SEP 2015 US Army Research Laboratory A Molecularly Imprinted Polymer (MIP)- Coated Microbeam MEMS Sensor for...ARL-RP-0536 ● SEP 2015 US Army Research Laboratory A Molecularly Imprinted Polymer (MIP)- Coated Microbeam MEMS Sensor for Chemical...TITLE AND SUBTITLE A Molecularly Imprinted Polymer (MIP)-Coated Microbeam MEMS Sensor for Chemical Detection 5a. CONTRACT NUMBER 5b. GRANT NUMBER

Genome-wide transcription responses to synchrotron microbeam radiotherapy.

PubMed

Sprung, Carl N; Yang, Yuqing; Forrester, Helen B; Li, Jason; Zaitseva, Marina; Cann, Leonie; Restall, Tina; Anderson, Robin L; Crosbie, Jeffrey C; Rogers, Peter A W

2012-10-01

The majority of cancer patients achieve benefit from radiotherapy. A significant limitation of radiotherapy is its relatively low therapeutic index, defined as the maximum radiation dose that causes acceptable normal tissue damage to the minimum dose required to achieve tumor control. Recently, a new radiotherapy modality using synchrotron-generated X-ray microbeam radiotherapy has been demonstrated in animal models to ablate tumors with concurrent sparing of normal tissue. Very little work has been undertaken into the cellular and molecular mechanisms that differentiate microbeam radiotherapy from broad beam. The purpose of this study was to investigate and compare the whole genome transcriptional response of in vivo microbeam radiotherapy versus broad beam irradiated tumors. We hypothesized that gene expression changes after microbeam radiotherapy are different from those seen after broad beam. We found that in EMT6.5 tumors at 4-48 h postirradiation, microbeam radiotherapy differentially regulates a number of genes, including major histocompatibility complex (MHC) class II antigen gene family members, and other immunity-related genes including Ciita, Ifng, Cxcl1, Cxcl9, Indo and Ubd when compared to broad beam. Our findings demonstrate molecular differences in the tumor response to microbeam versus broad beam irradiation and these differences provide insight into the underlying mechanisms of microbeam radiotherapy and broad beam.

Heavy Ion Microbeam- and Broadbeam-Induced Current Transients in SiGe HBTs

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Reed, R. A.; McMorrow, D.; Vizkelethy, G.; Ferlet-Cavrois, V.; Baggio, J.; Duhamel, O.; Moen, K. A.; Phillips, S. D.; Diestelhorst, R. M.;

Long term fine aerosol analysis by XRF and PIXE techniques in the city of Rijeka, Croatia

NASA Astrophysics Data System (ADS)

Ivošević, Tatjana; Orlić, Ivica; Radović, Iva Bogdanović

2015-11-01

The results of a long term, multi elemental XRF and PIXE analysis of fine aerosol pollution in the city of Rijeka, Croatia, are reported for the first time. The samples were collected during a seven months period (6th Aug 2013-28th Feb 2014) on thin stretched Teflon filters and analyzed by energy dispersive X-ray fluorescence (EDXRF) at the Laboratory for Elemental Micro-Analysis (LEMA), University of Rijeka and by Particle Induced X-ray Emission (PIXE) using 1.6 MeV protons at the Laboratory for Ion Beam Interactions (LIBI), Ruđer Bošković Institute, Zagreb. The newly developed micro-XRF system at LEMA provided results for 19 elements in the range from Si to Pb. The PIXE at the LIBI provided information for the same elements as well for the light elements such as Na, Mg and Al. Black carbon was determined with the Laser Integrated Plate Method (LIPM). The results were statistically evaluated by means of the positive matrix factorization (PMF). The seven major pollution sources were identified together with their relative contributions, these are: secondary sulfates, road traffic, smoke, road dust, sea spray, ship emissions and soil dust.

Comparison of PIXE and XRF analysis of airborne particulate matter samples collected on Teflon and quartz fibre filters

NASA Astrophysics Data System (ADS)

Chiari, M.; Yubero, E.; Calzolai, G.; Lucarelli, F.; Crespo, J.; Galindo, N.; Nicolás, J. F.; Giannoni, M.; Nava, S.

2018-02-01

Within the framework of research projects focusing on the sampling and analysis of airborne particulate matter, Particle Induced X-ray Emission (PIXE) and Energy Dispersive X-ray Fluorescence (ED-XRF) techniques are routinely used in many laboratories throughout the world to determine the elemental concentration of the particulate matter samples. In this work an inter-laboratory comparison of the results obtained from analysing several samples (collected on both Teflon and quartz fibre filters) using both techniques is presented. The samples were analysed by PIXE (in Florence, at the 3 MV Tandetron accelerator of INFN-LABEC laboratory) and by XRF (in Elche, using the ARL Quant'X EDXRF spectrometer with specific conditions optimized for specific groups of elements). The results from the two sets of measurements are in good agreement for all the analysed samples, thus validating the use of the ARL Quant'X EDXRF spectrometer and the selected measurement protocol for the analysis of aerosol samples. Moreover, thanks to the comparison of PIXE and XRF results on Teflon and quartz fibre filters, possible self-absorption effects due to the penetration of the aerosol particles inside the quartz fibre-filters were quantified.

PIXE and XRF Analysis of Roman Denarii

NASA Astrophysics Data System (ADS)

Fasano, Cecilia; Raddell, Mark; Manukyan, Khachatur; Stech, Edward; Wiescher, Michael

2017-09-01

A set of Roman Denarii from the republican to the imperial period (140BC-240AD) has been studied using X-ray fluorescent (XRF) scanning and proton induced x-ray emission (PIXE) techniques. XRF and PIXE are commonly used in the study of cultural heritage objects because they are nondestructive. The combination of these two methods is also unique because of the ability to penetrate the sample with a broader spectrum of depths and energies than either could achieve on its own. The coins are from a large span of Roman history and their analysis serves to follow the economic and political change of the era using the relative silver and copper contents in each sample. In addition to analyzing the samples, the study sought to compare these two common analysis techniques and to explore the use of a standard to examine any shortcomings in either of the methods. Data sets were compared and then adjusted to a calibration curve which was created from the analysis of a number of standard solutions. The concentrations of the standard solutions were confirmed using inductively coupled plasma spectroscopy. Through this we were able to assemble results which will progress the basis of understanding of PIXE and XRF techniques as well as increase the wealth of knowledge of Ancient Roman currency.

High resolution 3D imaging of synchrotron generated microbeams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gagliardi, Frank M., E-mail: frank.gagliardi@wbrc.org.au; Cornelius, Iwan; Blencowe, Anton

2015-12-15

Purpose: Microbeam radiation therapy (MRT) techniques are under investigation at synchrotrons worldwide. Favourable outcomes from animal and cell culture studies have proven the efficacy of MRT. The aim of MRT researchers currently is to progress to human clinical trials in the near future. The purpose of this study was to demonstrate the high resolution and 3D imaging of synchrotron generated microbeams in PRESAGE® dosimeters using laser fluorescence confocal microscopy. Methods: Water equivalent PRESAGE® dosimeters were fabricated and irradiated with microbeams on the Imaging and Medical Beamline at the Australian Synchrotron. Microbeam arrays comprised of microbeams 25–50 μm wide with 200more » or 400 μm peak-to-peak spacing were delivered as single, cross-fire, multidirectional, and interspersed arrays. Imaging of the dosimeters was performed using a NIKON A1 laser fluorescence confocal microscope. Results: The spatial fractionation of the MRT beams was clearly visible in 2D and up to 9 mm in depth. Individual microbeams were easily resolved with the full width at half maximum of microbeams measured on images with resolutions of as low as 0.09 μm/pixel. Profiles obtained demonstrated the change of the peak-to-valley dose ratio for interspersed MRT microbeam arrays and subtle variations in the sample positioning by the sample stage goniometer were measured. Conclusions: Laser fluorescence confocal microscopy of MRT irradiated PRESAGE® dosimeters has been validated in this study as a high resolution imaging tool for the independent spatial and geometrical verification of MRT beam delivery.« less

PIXE analysis of ancient Chinese Qing dynasty porcelain

NASA Astrophysics Data System (ADS)

Cheng, Huansheng; He, Wenquan; Tang, Jiayong; Yang, Fujia; Wang, Jianhua

1996-09-01

The major and minor chemical compositions and trace element content of white glaze made in Qing dynasty at kuan kiln have been determined by PIXE. Experimental results show that trace element contents RbSrZr are useful to distinguish the place of production of ancient porcelain. In the porcelain from different kilns situated in a same province, the trace element contents can be different from each other. Determining and comparing the major and minor compositions and trace elemental concentrations in white glaze by PIXE technique, we can distinguish a precious Qing dynasty porcelain made at kuan kiln from a fake.

Trace element fingerprinting of jewellery rubies by external beam PIXE

NASA Astrophysics Data System (ADS)

Calligaro, T.; Poirot, J.-P.; Querré, G.

1999-04-01

External beam PIXE analysis allows the non-destructive in situ characterisation of gemstones mounted on jewellery pieces. This technique was used for the determination of the geographical origin of 64 rubies set on a high-valued necklace. The trace element content of these gemstones was measured and compared to that of a set of rubies of known sources. Multivariate statistical processing of the results allowed us to infer the provenance of rubies : one comes from Thailand/Cambodia deposit while the remaining are attributed to Burma. This highlights the complementary capabilities of PIXE and conventional gemological observations.

Elastic recoil detection analysis for the determination of hydrogen concentration profiles in switchable mirrors

NASA Astrophysics Data System (ADS)

Huisman, M. C.; van der Molen, S. J.; Vis, R. D.

1999-10-01

Switchable mirrors [J.N. Huiberts, R. Griessen, J.H. Rector, R.J. Wijngaarden, J.P. Dekker, D.G. de Groot, N.J. Koeman, Nature 380 (1996) 231; J.N Huiberts, J.H. Rector, R.J. Wijngaarden, S. Jetten, D. de Groot, B. Dam, N.J.. Koeman, R. Griessen, B. Hjörvarsson, S Olafsson, Y.S. Cho, J. Alloys and Compounds 239 (1996) 158; F.J.A. den Broeder, S.J. van der Molen, M. Kremers, J. N. Huiberts, D.G. Nagengast, A.T.M. van Gogh, W.H. Huisman, N. J. Koeman, B. Dam, J.H. Rector, S. Plota, M. Haaksma, R.M.N. Hanzen, R.M. Jungblut, P.A. Duine, R. Griessen, Nature 394 (1998) 656] made of thin films of Y, La or rare-earth (RE) metals exhibit spectacular changes in their optical and electrical properties upon hydrogen loading. The study of these materials has indicated that the occurring phenomena are highly sensitive to the actual hydrogen concentration in these materials. In this paper elastic recoil detection analysis (ERDA) is used as a tool to measure hydrogen concentrations on a micrometer scale. The measurements have been performed using a 4He 2+ ion beam from a 1.7 MV Pelletron accelerator. The ion beam can be focused routinely to a spot size of approximately 10 μm 2. The experimental set-up enables the simultaneous measurement of Rutherford backscattering spectrometry (RBS) as well as particle induced X-ray emission (PIXE) spectra, which provide complementary information. The results of ERDA measurements on laterally diffused YH x (0< x<3) samples with a qualitatively known hydrogen concentration profile are presented and discussed. The calibration of the microbeam set-up and possible improvement of the measurement technique are described.

Micro-beam friction liner and method of transferring energy

DOEpatents

Mentesana, Charles [Leawood, KS

2007-07-17

A micro-beam friction liner adapted to increase performance and efficiency and reduce wear in a piezoelectric motor or actuator or other device using a traveling or standing wave to transfer energy in the form of torque and momentum. The micro-beam friction liner comprises a dense array of micro-beam projections having first ends fixed relative to a rotor and second ends projecting substantially toward a plurality of teeth of a stator, wherein the micro-beam projections are compressed and bent during piezoelectric movement of the stator teeth, thereby storing the energy, and then react against the stator teeth to convert the stored energy stored to rotational energy in the rotor.

Automated microbeam observation environment for biological analysis-Custom portable environmental control applied to a vertical microbeam system.

PubMed

England, Matthew J; Bigelow, Alan W; Merchant, Michael J; Velliou, Eirini; Welch, David; Brenner, David J; Kirkby, Karen J

2017-02-01

Vertical Microbeams (VMB) are used to irradiate individual cells with low MeV energy ions. The irradiation of cells using VMBs requires cells to be removed from an incubator; this can cause physiological changes to cells because of the lower CO 2 concentration, temperature and relative humidity outside of the incubator. Consequently, for experiments where cells require irradiation and observation for extended time periods, it is important to provide a controlled environment. The highly customised nature of the microscopes used on VMB systems means that there are no commercially available environmentally controlled microscope systems for VMB systems. The Automated Microbeam Observation Environment for Biological Analysis (AMOEBA) is a highly flexible modular environmental control system used to create incubator conditions on the end of a VMB. The AMOEBA takes advantage of the recent "maker" movement to create an open source control system that can be easily configured by the user to fit their control needs even beyond VMB applications. When applied to the task of controlling cell medium temperature, CO 2 concentration and relative humidity on VMBs it creates a stable environment that allows cells to multiply on the end of a VMB over a period of 36 h, providing a low-cost (costing less than $2700 to build), customisable alternative to commercial time-lapse microscopy systems. AMOEBA adds the potential of VMBs to explore the long-term effects of radiation on single cells opening up new research areas for VMBs.

Evaluation of specimen preparation techniques for micro-PIXE localisation of elements in hyperaccumulating plants

NASA Astrophysics Data System (ADS)

Kachenko, Anthony G.; Siegele, Rainer; Bhatia, Naveen P.; Singh, Balwant; Ionescu, Mihail

2008-04-01

Hybanthus floribundus subsp. floribundus, a rare Australian Ni-hyperaccumulating shrub and Pityrogramma calomelanos var. austroamericana, an Australian naturalized As-hyperaccumulating fern are promising species for use in phytoremediation of contaminated sites. Micro-proton-induced X-ray emission (μ-PIXE) spectroscopy was used to map the elemental distribution of the accumulated metal(loid)s, Ca and K in leaf or pinnule tissues of the two plant species. Samples were prepared by two contrasting specimen preparation techniques: freeze-substitution in tetrahydrofuran (THF) and freeze-drying. The specimens were analysed to compare the suitability of each technique in preserving (i) the spatial elemental distribution and (ii) the tissue structure of the specimens. Further, the μ-PIXE results were compared with concentration of elements in the bulk tissue obtained by ICP-AES analysis. In H. floribundus subsp. floribundus, μ-PIXE analysis revealed Ni, Ca and K concentrations in freeze-dried leaf tissues were at par with bulk tissue concentrations. Elemental distribution maps illustrated that Ni was preferentially localised in the adaxial epidermal tissues (1% DW) and least concentration was found in spongy mesophyll tissues (0.53% DW). Conversely, elemental distribution maps of THF freeze-substituted tissues indicated significantly lower Ni, Ca and K concentrations than freeze-dried specimens and bulk tissue concentrations. Moreover, Ni concentrations were uniform across the whole specimen and no localisation was observed. In P. calomelanos var. austroamericana freeze-dried pinnule tissues, μ-PIXE revealed statistically similar As, Ca and K concentrations as compared to bulk tissue concentrations. Elemental distribution maps showed that As localisation was relatively uniform across the whole specimen. Once again, THF freeze-substituted tissues revealed a significant loss of As compared to freeze-dried specimens and the concentrations obtained by bulk tissue analysis. The results demonstrate that freeze-drying is a suitable sample preparation technique to study elemental distribution of ions in H. floribundus and P. calomelanos plant tissues using μ-PIXE spectroscopy. Furthermore, cellular structure was preserved in samples prepared using this technique.

Nonlinear-Based MEMS Sensors and Active Switches for Gas Detection.

PubMed

Bouchaala, Adam; Jaber, Nizar; Yassine, Omar; Shekhah, Osama; Chernikova, Valeriya; Eddaoudi, Mohamed; Younis, Mohammad I

2016-05-25

The objective of this paper is to demonstrate the integration of a MOF thin film on electrostatically actuated microstructures to realize a switch triggered by gas and a sensing algorithm based on amplitude tracking. The devices are based on the nonlinear response of micromachined clamped-clamped beams. The microbeams are coated with a metal-organic framework (MOF), namely HKUST-1, to achieve high sensitivity. The softening and hardening nonlinear behaviors of the microbeams are exploited to demonstrate the ideas. For gas sensing, an amplitude-based tracking algorithm is developed to quantify the captured quantity of gas. Then, a MEMS switch triggered by gas using the nonlinear response of the microbeam is demonstrated. Noise analysis is conducted, which shows that the switch has high stability against thermal noise. The proposed switch is promising for delivering binary sensing information, and also can be used directly to activate useful functionalities, such as alarming.

Mechanical analysis of non-uniform bi-directional functionally graded intelligent micro-beams using modified couple stress theory

NASA Astrophysics Data System (ADS)

Bakhshi Khaniki, Hossein; Rajasekaran, Sundaramoorthy

2018-05-01

This study develops a comprehensive investigation on mechanical behavior of non-uniform bi-directional functionally graded beam sensors in the framework of modified couple stress theory. Material variation is modelled through both length and thickness directions using power-law, sigmoid and exponential functions. Moreover, beam is assumed with linear, exponential and parabolic cross-section variation through the length using power-law and sigmoid varying functions. Using these assumptions, a general model for microbeams is presented and formulated by employing Hamilton’s principle. Governing equations are solved using a mixed finite element method with Lagrangian interpolation technique, Gaussian quadrature method and Wilson’s Lagrangian multiplier method. It is shown that by using bi-directional functionally graded materials in nonuniform microbeams, mechanical behavior of such structures could be affected noticeably and scale parameter has a significant effect in changing the rigidity of nonuniform bi-directional functionally graded beams.

Microbeam Characterization of Corning Archeological Reference Glasses: New Additions to the Smithsonian Microbeam Standard Collection

PubMed Central

Vicenzi, Edward P.; Eggins, Stephen; Logan, Amelia; Wysoczanski, Richard

2002-01-01

An initial study of the minor element, trace element, and impurities in Corning archeological references glasses have been performed using three microbeam techniques: electron probe microanalysis (EPMA), laser ablation ICP-mass spectrometry (LA ICP-MS), and secondary ion mass spectrometry (SIMS). The EPMA results suggest a significant level of heterogeneity for a number of metals. Conversely, higher precision and a larger sampling volume analysis by LA ICP-MS indicates a high degree of chemical uniformity within all glasses, typically <2 % relative (1 σ). SIMS data reveal that small but measurable quantities of volatile impurities are present in the glasses, including H at roughly the 0.0001 mass fraction level. These glasses show promise for use as secondary standards for minor and trace element analyses of insulating materials such as synthetic ceramics, minerals, and silicate glasses. PMID:27446764

Nonlinear-Based MEMS Sensors and Active Switches for Gas Detection

PubMed Central

Bouchaala, Adam; Jaber, Nizar; Yassine, Omar; Shekhah, Osama; Chernikova, Valeriya; Eddaoudi, Mohamed; Younis, Mohammad I.

2016-01-01

The objective of this paper is to demonstrate the integration of a MOF thin film on electrostatically actuated microstructures to realize a switch triggered by gas and a sensing algorithm based on amplitude tracking. The devices are based on the nonlinear response of micromachined clamped-clamped beams. The microbeams are coated with a metal-organic framework (MOF), namely HKUST-1, to achieve high sensitivity. The softening and hardening nonlinear behaviors of the microbeams are exploited to demonstrate the ideas. For gas sensing, an amplitude-based tracking algorithm is developed to quantify the captured quantity of gas. Then, a MEMS switch triggered by gas using the nonlinear response of the microbeam is demonstrated. Noise analysis is conducted, which shows that the switch has high stability against thermal noise. The proposed switch is promising for delivering binary sensing information, and also can be used directly to activate useful functionalities, such as alarming. PMID:27231914

Genetics of the Blue Light-Dependent Signal Cascade That Controls Phototaxis in the Cyanobacterium Synechocystis sp. PCC6803.

PubMed

Sugimoto, Yuki; Nakamura, Hiroshi; Ren, Shukun; Hori, Koichi; Masuda, Shinji

2017-03-01

The Synechocystis sp. PCC6803 can move on a solid surface in response to light, a phenomenon called phototaxis. Although many of the photoreceptors involved in phototaxis have been identified, the mechanisms that regulate directional motility of Synechocystis are not well understood. Previous studies showed that a mutant lacking the blue light-using flavin (BLUF) photoreceptor PixD exhibits negative phototaxis under conditions where the wild type responds positively. PixD interacts with the pseudo-response regulator-like protein PixE in a light-dependent manner, suggesting that this intermolecular interaction is important for phototaxis regulation, although genetic evidence has been lacking. To gain further insight into phototaxis regulation by PixD-PixE signaling, we constructed the deletion mutants ΔPixE and ΔPixD-ΔPixE, and characterized their phenotypes, which matched those of the wild type (positive phototaxis). Because ΔPixD exhibited negative phototaxis, PixE must function downstream of PixD. Under intense blue light (>100 μmol m-2 s-1; 470 nm) the wild type exhibited negative phototaxis, but ΔPixD-PixE exhibited positive phototaxis toward low-intensity blue light (∼0.8 μmol m-2 s-1; 470 nm). These results suggest that an unknown light-sensing system(s), that is necessary for directional cell movement, can be activated by low-intensity blue light; on the other hand, PixD needs high-intensity blue light to be activated. We also isolated spontaneous mutants that compensated for the pixE deletion. Genome-wide sequencing of the mutants revealed that the uncharacterized gene sll2003 regulates positive and negative phototaxis in response to light intensity. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Analysis of Pull-In Instability of Geometrically Nonlinear Microbeam Using Radial Basis Artificial Neural Network Based on Couple Stress Theory

PubMed Central

Heidari, Mohammad; Heidari, Ali; Homaei, Hadi

2014-01-01

The static pull-in instability of beam-type microelectromechanical systems (MEMS) is theoretically investigated. Two engineering cases including cantilever and double cantilever microbeam are considered. Considering the midplane stretching as the source of the nonlinearity in the beam behavior, a nonlinear size-dependent Euler-Bernoulli beam model is used based on a modified couple stress theory, capable of capturing the size effect. By selecting a range of geometric parameters such as beam lengths, width, thickness, gaps, and size effect, we identify the static pull-in instability voltage. A MAPLE package is employed to solve the nonlinear differential governing equations to obtain the static pull-in instability voltage of microbeams. Radial basis function artificial neural network with two functions has been used for modeling the static pull-in instability of microcantilever beam. The network has four inputs of length, width, gap, and the ratio of height to scale parameter of beam as the independent process variables, and the output is static pull-in voltage of microbeam. Numerical data, employed for training the network, and capabilities of the model have been verified in predicting the pull-in instability behavior. The output obtained from neural network model is compared with numerical results, and the amount of relative error has been calculated. Based on this verification error, it is shown that the radial basis function of neural network has the average error of 4.55% in predicting pull-in voltage of cantilever microbeam. Further analysis of pull-in instability of beam under different input conditions has been investigated and comparison results of modeling with numerical considerations shows a good agreement, which also proves the feasibility and effectiveness of the adopted approach. The results reveal significant influences of size effect and geometric parameters on the static pull-in instability voltage of MEMS. PMID:24860602

Development of a TOF SIMS setup at the Zagreb heavy ion microbeam facility

NASA Astrophysics Data System (ADS)

Tadić, Tonči; Bogdanović Radović, Iva; Siketić, Zdravko; Cosic, Donny Domagoj; Skukan, Natko; Jakšić, Milko; Matsuo, Jiro

2014-08-01

We describe a new Time-of-flight Secondary Ion Mass Spectrometry (TOF SIMS) setup for MeV SIMS application, which is constructed and installed at the heavy ion microbeam facility at the Ruđer Bošković Institute in Zagreb. The TOF-SIMS setup is developed for high sensitivity molecular imaging using a heavy ion microbeam that focuses ion beams (from C to I) with sub-micron resolution. Dedicated pulse processing electronics for MeV SIMS application have been developed, enabling microbeam-scanning control, incoming ion microbeam pulsing and molecular mapping. The first results showing measured MeV SIMS spectra as well as molecular maps for samples of interest are presented and discussed.

Determination of Hg concentration in gases by PIXE

NASA Astrophysics Data System (ADS)

Dutkiewicz, E.; van Kuijen, W. J. P.; Munnik, F.; Mutsaers, P. H. A.; Rokita, E.; de Voigt, M. J. A.

1992-05-01

A method for determination of the concentration of mercury in the gaseous phase is described. In the first step of the method a stable sulphur-mercury complex is formed. For this purpose sulphur is deposited on a filter and the investigated gas flows through the filter. Millipore filters and the deposition of sulphur from Na2S2O3 * 5H2O solution were found to be most suitable. The amount of Hg absorbed on the filter was determined by PIXE or by NAA in the second step of the method. An optimization of proton energy was performed in the PIXE analysis to obtain the maximal signal-to-background ratio. The detection limit of the method, expressed as the minimal amount of Hg which has to flow through the filter equals to 30 and 2 ng for PIXE and NAA techniques, respectively. Applications of the method are also described.

Laser microtreatment for genetic manipulations and DNA diagnostics by a combination of microbeam and photonic tweezers (laser microbeam trap)

NASA Astrophysics Data System (ADS)

Greulich, Karl-Otto; Monajembashi, Shamci; Celeda, D.; Endlich, N.; Eickhoff, Holger; Hoyer, Carsten; Leitz, G.; Weber, Gerd; Scheef, J.; Rueterjans, H.

1994-12-01

Genomes of higher organisms are larger than one typically expects. For example, the DNA of a single human cell is almost two meters long, the DNA in the human body covers the distance Earth-Sun approximately 140 times. This is often not considered in typical molecular biological approaches for DNA diagnostics, where usually only DNA of the length of a gene is investigated. Also, one basic aspect of sequencing the human genome is not really solved: the problem how to prepare the huge amounts of DNA required. Approaches from biomedical optics combined with new developments in single molecule biotechnology may at least contribute some parts of the puzzle. A large genome can be partitioned into portions comprising approximately 1% of the whole DNA using a laser microbeam. The single DNA fragment can be amplified by the polymerase chain reaction in order to obtain a sufficient amount of molecules for conventional DNA diagnostics or for analysis by octanucleotide hybridization. When not amplified by biotechnological processes, the individual DNA molecule can be visualized in the light microscope and can be manipulated and dissected with the laser microbeam trap. The DNA probes obtained by single molecule biotechnology can be employed for fluorescence in situ introduced into plant cells and subcellular structures even when other techniques fail. Since the laser microbeam trap allows to work in the interior of a cell without opening it, subcellular structures can be manipulated. For example, in algae, such structures can be moved out of their original position and used to study intracellular viscosities.

An accelerator-based neutron microbeam system for studies of radiation effects

PubMed Central

Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A.; Bigelow, Alan W.; Akselrod, Mark S.; Sykora, Jeff G.; Brenner, David J.

2011-01-01

A novel neutron microbeam is being developed at the Radiological Research Accelerator Facility (RARAF) of Columbia University. The RARAF microbeam facility has been used for studies of radiation bystander effects in mammalian cells for many years. Now a prototype neutron microbeam is being developed that can be used for bystander effect studies. The neutron microbeam design here is based on the existing charged particle microbeam technology at the RARAF. The principle of the neutron microbeam is to use the proton beam with a micrometre-sized diameter impinging on a very thin lithium fluoride target system. From the kinematics of the 7Li(p,n)7Be reaction near the threshold of 1.881 MeV, the neutron beam is confined within a narrow, forward solid angle. Calculations show that the neutron spot using a target with a 17-µm thick gold backing foil will be <20 µm in diameter for cells attached to a 3.8-µm thick propylene-bottomed cell dish in contact with the target backing. The neutron flux will roughly be 2000 per second based on the current beam setup at the RARAF singleton accelerator. The dose rate will be about 200 mGy min−1. The principle of this neutron microbeam system has been preliminarily tested at the RARAF using a collimated proton beam. The imaging of the neutron beam was performed using novel fluorescent nuclear track detector technology based on Mg-doped luminescent aluminum oxide single crystals and confocal laser scanning fluorescent microscopy. PMID:21131327

PIXE Analysis of Ceramic Artifacts

NASA Astrophysics Data System (ADS)

High, Elizabeth; Lamm, Larry; Schurr, Mark; Stech, Edward; Wiescher, Michael

2009-10-01

Particle Induced X-ray Emissions, or PIXE, is a nuclear physics technique used as a non-destructive material analysis method which gives a detailed and comprehensive profile of the elemental composition of a target. Using the University of Notre Dame KN and FN accelerators in the ISNAP laboratory a beam of particles, here protons, is accelerated and used to knock out electrons from lower orbitals within the target resulting in characteristic X-rays. Under optimum operating conditions data from PIXE can not only give information about which elements are present in a sample but also their relative abundances in parts per million. In a previous run done in collaboration with the Anthropology Department at the University of Notre Dame pottery shards from the Collier Lodge, located in northwest Indiana, were analyzed and only relative abundances were able to be compared between samples. We are now implementing a new setup into the beam-line which will incorporate the ability to take Rutherford Back Scattering, or RBS, measurements of the beam during the PIXE runs, which will allow for a standard normalization for the runs and give the facility the ability to acquire a more absolute and quantitative analysis of the data. Initial results using the same pottery shards as a comparative data set will be presented.

An attempt to diagnose cancer by PIXE

NASA Astrophysics Data System (ADS)

Uda, M.; Maeda, K.; Sasa, Y.; Kusuyama, H.; Yokode, Y.

1987-03-01

PIXE is suitable especially for trace elemental analysis for atoms with high atomic numbers, which are contained in matrices composed mainly of light elements such as biological materials. An attempt has been made to distinguish elemental concentrations of cancer tissues from those of normal ones. Kidney, testis and urinary bladder cancer tissues were examined by PIXE. Key elements to diagnose these cancers were Ca, Ti, Cr, Fe and Zn. Enrichment of Fe and Ti, and deficiency of Zn could be seen in the kidney cancer. An opposite tendency was observed in the testicular cancer. Imbalance of these elemental concentrations in characteristic organs might give us a possibility for cancer diagnosis.

PIXE analysis of Chinese ancient greenish white porcelain

NASA Astrophysics Data System (ADS)

Cheng, Lin; Ding, Xun-liang; Feng, Song-lin; Cheng, Huang-sheng; Zhang, Wen-Jiang; Fan, Chang-Sheng

2006-03-01

This paper reports the results about the PIXE analysis of major, minor and trace elements of Chinese ancient greenish white porcelain and blue-and-white porcelain produced in Hutian Kiln (Jingdezhen district, Jiangxi province) during 10th-14th centuries. The porcelain body and greenish white glaze from northern Song (AD 960), southern Song (AD 1037-1276), early Yuan (AD 1279-1320), later Yuan (AD 1320-1368) were investigated together with white-and-blue glaze from Ming dynasty (AD 1368-1644). The obtained data were further analyzed by factor analysis.

Biomedical studies by PIXE

NASA Astrophysics Data System (ADS)

Afarideh, H.; Amirabadi, A.; Hadji-Saeid, S. M.; Mansourian, N.; Kaviani, K.; Zibafar, E.

1996-04-01

In the present biomedical research, PIXE a powerful technique for elemental analysis was employed to illustrate the importance of multi-elemental determination of serum trace elements in two cases of great medical interest. Those are evaluation of the desferroxamine drug (DPO), a widely used therapy for patient with β-thalassemia-Major (β-thal-M), and investigation of elemental variations in blood-serum in hyperbilirubinamia new-borns before and after blood transfusion (BT). The purpose of the work is to demonstrate the various aspects of PIXE analysis by some practical examples as well as to draw some general conclusions regarding the cure of those patients with the above mentioned disorders or diseases. To present in details each case, we divide the paper in two parts: part 1 and part 2 to consider the experimental procedure as well as the results individually.

Manipulation of cells with laser microbeam scissors and optical tweezers: a review

NASA Astrophysics Data System (ADS)

Greulich, Karl Otto

2017-02-01

The use of laser microbeams and optical tweezers in a wide field of biological applications from genomic to immunology is discussed. Microperforation is used to introduce a well-defined amount of molecules into cells for genetic engineering and optical imaging. The microwelding of two cells induced by a laser microbeam combines their genetic outfit. Microdissection allows specific regions of genomes to be isolated from a whole set of chromosomes. Handling the cells with optical tweezers supports investigation on the attack of immune systems against diseased or cancerous cells. With the help of laser microbeams, heart infarction can be simulated, and optical tweezers support studies on the heartbeat. Finally, laser microbeams are used to induce DNA damage in living cells for studies on cancer and ageing.

Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo.

PubMed

Brönnimann, Daniel; Bouchet, Audrey; Schneider, Christoph; Potez, Marine; Serduc, Raphaël; Bräuer-Krisch, Elke; Graber, Werner; von Gunten, Stephan; Laissue, Jean Albert; Djonov, Valentin

2016-09-19

Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25-100 μm wide) and minibeams (200-800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a(+) thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool.

Trace elemental analysis of Indian natural moonstone gems by PIXE and XRD techniques.

PubMed

Venkateswara Rao, R; Venkateswarulu, P; Kasipathi, C; Sivajyothi, S

2013-12-01

A selected number of Indian Eastern Ghats natural moonstone gems were studied with a powerful nuclear analytical and non-destructive Proton Induced X-ray Emission (PIXE) technique. Thirteen elements, including V, Co, Ni, Zn, Ga, Ba and Pb, were identified in these moonstones and may be useful in interpreting the various geochemical conditions and the probable cause of their inceptions in the moonstone gemstone matrix. Furthermore, preliminary XRD studies of different moonstone patterns were performed. The PIXE technique is a powerful method for quickly determining the elemental concentration of a substance. A 3MeV proton beam was employed to excite the samples. The chemical constituents of moonstones from parts of the Eastern Ghats geological formations of Andhra Pradesh, India were determined, and gemological studies were performed on those gems. The crystal structure and the lattice parameters of the moonstones were estimated using X-Ray Diffraction studies, trace and minor elements were determined using the PIXE technique, and major compositional elements were confirmed by XRD. In the present work, the usefulness and versatility of the PIXE technique for research in geo-scientific methodology is established. © 2013 Elsevier Ltd. All rights reserved.

Quantitative analysis of major elements in silicate minerals and glasses by micro-PIXE

USGS Publications Warehouse

Campbell, J.L.; Czamanske, G.K.; MacDonald, L.; Teesdale, W.J.

1997-01-01

The Guelph micro-PIXE facility has been modified to accommodate a second Si(Li) X-ray detector which records the spectrum due to light major elements (11 ??? Z ??? 20) with no deleterious effects from scattered 3 MeV protons. Spectra have been recorded from 30 well-characterized materials, including a broad range of silicate minerals and both natural and synthetic glasses. Sodium is mobile in some of the glasses, but not in the studied mineral lattices. The mean value of the instrumental constant H for each of the elements Mg, Al, and Si in these materials is systematically 6-8% lower than the H-value measured for the pure metals. Normalization factors are derived which permit the matrix corrections requisite for trace-element measurements in silicates to be based upon pure metal standards for Mg, Al and Si, supplemented by well-established, silicate mineral standards for the elements Na, K and Ca. Rigorous comparisons of electron microprobe and micro-PIXE analyses for the entire, 30-sample suite demonstrate the ability of micro-PIXE to produce accurate analysis for the light major elements in silicates. ?? 1997 Elsevier Science B.V.

PIXE and PGAA - Complementary methods for studies on ancient glass artefacts (from Byzantine, late medieval to modern Murano glass)

NASA Astrophysics Data System (ADS)

Constantinescu, Bogdan; Cristea-Stan, Daniela; Szőkefalvi-Nagy, Zoltán; Kovács, Imre; Harsányi, Ildikó; Kasztovszky, Zsolt

2018-02-01

Combined external milli-beam Particle Induced X-ray Emission (PIXE) and Prompt Gamma Activation Analysis (PGAA) analysis was applied to characterize the composition of paste and colorants from some fragments of Byzantine bracelets (10th-12th Centuries AD), late medieval (17th-18th Centuries AD) and modern Murano glass pieces. As fluxes, PGAA revealed the samples are soda-lime glass, except four samples - two medieval vessel white shards and two dark Byzantine fragments of bracelets - which have potash flux. Aluminium was detected in various proportions in all samples indicating different sources for the added sand. The presence of Magnesium is relevant only in one bracelet fragment suggesting the use of plant (wood?) ash and confirming that the Byzantine bracelet is manufactured from the mixture of both types of glass (natron and plant ash based). PGAA also indicated the presence of low quantities of Cadmium, high level of Arsenic and Lead (possibly lead arsenate) in one medieval sample and of ZnO in Murano glass, and of CoO traces (maximum 0.1%) in all blue-colored Byzantine, late medieval to modern Murano glass artefacts. PIXE confirmed the use of small quantities of CoO for blue color, indicated Manganese combined with Iron for dark glass, Copper for green, Lead, Tin and an Arsenic compound (orpiment?) for yellow and in the case of modern Murano glass Selenium and Cadmium to obtain a reddish color. Despite PIXE - PIGE combination is probably the best one for glass analysis, our external milli-PIXE - PGAA methods proved to be adequate complementary tools to determine many chemical elements from glass composition - Si, Na, K, Ca, Al, Mg, various metallic oxides.

Analysis of positional isotope exchange in ATP by cleavage of the beta P-O gamma P bond. Demonstration of negligible positional isotope exchange by myosin.

PubMed

Dale, M P; Hackney, D D

1987-12-15

A method for analysis of positional isotope exchange (PIX) during ATP in equilibrium with HOH oxygen exchange is presented that uses a two-step degradation of ATP resulting in cleavage of the beta P-O gamma P bond. This cleavage yields Pi derived from the gamma-phosphoryl of ATP that contains all four of the gamma oxygens. Both PIX between the beta,gamma-bridge and beta-nonbridge positions and washout of the gamma-nonbridge oxygens can be simultaneously followed by using ATP labeled with 17O at the beta-nonbridge positions and 18O at the beta,gamma-bridge and gamma-nonbridge positions. Application of this method to ATP in equilibrium with HOH exchange during single turnovers of myosin indicates that the bulk of the ATP undergoes rapid washout of gamma-nonbridge oxygens in the virtual absence of PIX. At 25 degrees C with subfragment 1 the scrambling rate is at the limit of detectability of approximately 0.001 s-1, which is 50-fold slower than the steady-state rate. This corresponds to a probability of scrambling for the beta-oxygens of bound ADP of 1 in 10,000 for each cycle of reversible hydrolysis of bound ATP. A fraction of the ATP, however, does not undergo rapid washout. With myosin and stoichiometric ATP at 0 degrees C, this fraction corresponds to 10% of the ATP remaining at 36 s, or 2% of the initial ATP, and an equivalent level of ATP is found that does not bind irreversibly to myosin in a cold chase experiment. A significant level of apparent PIX is observed with subfragment 1 in the fraction that resists washout, and this apparent PIX is shown to be due to contaminant adenylate kinase activity. This apparent PIX due to adenylate kinase provides a possible explanation for the PIX observed by Geeves et al. [Geeves, M. A., Webb, M. R., Midelfort, C. F., & Trentham, D. R. (1980) Biochemistry 19, 4748-4754] with subfragment 1.

αPIX Is a Trafficking Regulator that Balances Recycling and Degradation of the Epidermal Growth Factor Receptor

PubMed Central

Kortüm, Fanny; Harms, Frederike Leonie; Hennighausen, Natascha; Rosenberger, Georg

2015-01-01

Endosomal sorting is an essential control mechanism for signaling through the epidermal growth factor receptor (EGFR). We report here that the guanine nucleotide exchange factor αPIX, which modulates the activity of Rho-GTPases, is a potent bimodal regulator of EGFR trafficking. αPIX interacts with the E3 ubiquitin ligase c-Cbl, an enzyme that attaches ubiquitin to EGFR, thereby labelling this tyrosine kinase receptor for lysosomal degradation. We show that EGF stimulation induces αPIX::c-Cbl complex formation. Simultaneously, αPIX and c-Cbl protein levels decrease, which depends on both αPIX binding to c-Cbl and c-Cbl ubiquitin ligase activity. Through interaction αPIX sequesters c-Cbl from EGFR and this results in reduced EGFR ubiquitination and decreased EGFR degradation upon EGF treatment. However, quantitatively more decisive for cellular EGFR distribution than impaired EGFR degradation is a strong stimulating effect of αPIX on EGFR recycling to the cell surface. This function depends on the GIT binding domain of αPIX but not on interaction with c-Cbl or αPIX exchange activity. In summary, our data demonstrate a previously unappreciated function of αPIX as a strong promoter of EGFR recycling. We suggest that the novel recycling regulator αPIX and the degradation factor c-Cbl closely cooperate in the regulation of EGFR trafficking: uncomplexed αPIX and c-Cbl mediate a positive and a negative feedback on EGFR signaling, respectively; αPIX::c-Cbl complex formation, however, results in mutual inhibition, which may reflect a stable condition in the homeostasis of EGF-induced signal flow. PMID:26177020

Metabolic oxygen consumption measurement with a single-cell biosensor after particle microbeam irradiation

PubMed Central

Zhang, Bo; Messerli, Mark; Randers-Pehrson, Gerhard; Hei, Tom K.; Brenner, David J.

2015-01-01

A noninvasive, self-referencing biosensor/probe system has been integrated into the Columbia University Radiological Research Accelerator Facility Microbeam II end station. A single-cell oxygen consumption measurement has been conducted with this type of oxygen probe in 37°C Krebs–Ringer Bicarbonate buffer immediately before and after a single-cell microbeam irradiation. It is the first such measurement made for a microbeam irradiation, and a six fold increment of oxygen flux induced during a 15-s period of time has been observed following radiation exposure. The experimental procedure and the results are discussed. PMID:25335641

On the incorporation of trace elements into human hair measured with micro-PIXE

NASA Astrophysics Data System (ADS)

Bos, A. J. J.; Van Der Stap, C. C. A. H.; Valković, V.; Vis, R. D.; Verheul, H.

1984-04-01

A study has been made on the incorporation of trace elements into human hair by measuring concentration distributions across hair diameters of selected samples using the Amsterdam proton microbeam. Because hair is considered as a recording filament, reflecting metabolic changes over a period of time, a hair of a young mother was plucked 4 months after delivery of her first child. No change in the Zn and Cu concentrations correlated with the period of gestation was observed. A strong increase of Ca in the distal end must be attributed to outside contamination. From a study of a hair root, including the root sheaths, it is found that the method of incorporation of sulfur (minor element) differs strikingly from the behaviour of the trace elements Zn, Cu, Fe and Ca. The Zn and Cu distributions provide evidence of a, not yet reported, transversal transcellular input route, in which the root sheaths play an important role. From the results it is deduced that Zn and Cu seem to be distributed homogeneously by nature, while Fe, present at a high level in the root sheaths, seems to be peaked by nature on the periphery. The results are discussed against the background of the range of values of concentrations of certain elements found in the literature.

mRNA expression profiling of laser microbeam microdissected cells from slender embryonic structures.

PubMed

Scheidl, Stefan J; Nilsson, Sven; Kalén, Mattias; Hellström, Mats; Takemoto, Minoru; Håkansson, Joakim; Lindahl, Per

2002-03-01

Microarray hybridization has rapidly evolved as an important tool for genomic studies and studies of gene regulation at the transcriptome level. Expression profiles from homogenous samples such as yeast and mammalian cell cultures are currently extending our understanding of biology, whereas analyses of multicellular organisms are more difficult because of tissue complexity. The combination of laser microdissection, RNA amplification, and microarray hybridization has the potential to provide expression profiles from selected populations of cells in vivo. In this article, we present and evaluate an experimental procedure for global gene expression analysis of slender embryonic structures using laser microbeam microdissection and laser pressure catapulting. As a proof of principle, expression profiles from 1000 cells in the mouse embryonic (E9.5) dorsal aorta were generated and compared with profiles for captured mesenchymal cells located one cell diameter further away from the aortic lumen. A number of genes were overexpressed in the aorta, including 11 previously known markers for blood vessels. Among the blood vessel markers were endoglin, tie-2, PDGFB, and integrin-beta1, that are important regulators of blood vessel formation. This demonstrates that microarray analysis of laser microbeam micro-dissected cells is sufficiently sensitive for identifying genes with regulative functions.

Synchrotron microbeam irradiation induces neutrophil infiltration, thrombocyte attachment and selective vascular damage in vivo

PubMed Central

Brönnimann, Daniel; Bouchet, Audrey; Schneider, Christoph; Potez, Marine; Serduc, Raphaël; Bräuer-Krisch, Elke; Graber, Werner; von Gunten, Stephan; Laissue, Jean Albert; Djonov, Valentin

2016-01-01

Our goal was the visualizing the vascular damage and acute inflammatory response to micro- and minibeam irradiation in vivo. Microbeam (MRT) and minibeam radiation therapies (MBRT) are tumor treatment approaches of potential clinical relevance, both consisting of parallel X-ray beams and allowing the delivery of thousands of Grays within tumors. We compared the effects of microbeams (25–100 μm wide) and minibeams (200–800 μm wide) on vasculature, inflammation and surrounding tissue changes during zebrafish caudal fin regeneration in vivo. Microbeam irradiation triggered an acute inflammatory response restricted to the regenerating tissue. Six hours post irradiation (6 hpi), it was infiltrated by neutrophils and fli1a+ thrombocytes adhered to the cell wall locally in the beam path. The mature tissue was not affected by microbeam irradiation. In contrast, minibeam irradiation efficiently damaged the immature tissue at 6 hpi and damaged both the mature and immature tissue at 48 hpi. We demonstrate that vascular damage, inflammatory processes and cellular toxicity depend on the beam width and the stage of tissue maturation. Minibeam irradiation did not differentiate between mature and immature tissue. In contrast, all irradiation-induced effects of the microbeams were restricted to the rapidly growing immature tissue, indicating that microbeam irradiation could be a promising tumor treatment tool. PMID:27640676

PIXE analysis of Nigerian flour and bread samples

NASA Astrophysics Data System (ADS)

Olise, Felix S.; Fernandes, Adriana M.; Cristina Chaves, P.; Taborda, Ana; Reis, Miguel A.

2014-01-01

The alleged use of potassium bromate (KBrO3) in bread baking led a few authors to report on the chemical methods for the determination of KBrO3 levels in bread. In order to examine the potentials of a non chemical particle induced X-ray emission (PIXE) method for this purpose, six sets of samples, each composed of flour, dough and bread from a production batch were analysed. The samples were obtained from six different bakers of bread at Ile-Ife, Nigeria. The flour samples were air-dried while others were freeze dried at about -16 °C. The samples were homogenised in an agate mortar and then pelletised. Samples were analysed at the CTN standard PIXE setup and standard procedures for thick target samples analysis were followed. In some samples significant concentrations of bromine were found. In the present work we present possible explanations for the presence of this potentially dangerous contaminant in the samples.

Comparative trace elemental analysis of cancerous and non-cancerous tissues of rectal cancer patients using PIXE

NASA Astrophysics Data System (ADS)

Naga Raju, G. J.; Sarita, P.; Murthy, K. S. R.

2017-08-01

Particle Induced X-ray Emission (PIXE), an accelerator based analytical technique has been employed in this work for the analysis of trace elements in the cancerous and non-cancerous tissues of rectal cancer patients. A beam of 3 MeV protons generated from 3 MV Pelletron accelerator at the Ion Beam Laboratory of Institute of Physics, Bhubaneswar, India was used as projectile to excite the atoms present in the tissues samples. PIXE technique, with its capability to detect simultaneously several elements present at very low concentrations, offers an excellent tool for trace element analysis. The characteristic X-rays emitted by the samples were recorded by a high resolution Si (Li) detector. On the basis of the PIXE spectrum obtained for each sample, the elements Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, and Br were identified and their relative concentrations were estimated in the cancerous and non-cancerous tissues of rectum. The levels of Mn, Fe, Co, Cu, Zn, and As were higher (p < 0.005) while the levels of Ca, Cr and Ni were lower (p < 0.005) in the cancer tissues relative to the normal tissues. The alterations in the levels of the trace elements observed in the present work are discussed in this paper with respect to their potential role in the initiation, promotion and inhibition of cancer of the rectum.

Characterization and application of automated in-vacuum PIXE/EBS system for direct analysis of chloride and sulfate ions attack in cementitious materials

NASA Astrophysics Data System (ADS)

Rihawy, M. S.; Alwazzeh, M.; Abbas, K.

2018-01-01

Ion beam analysis (IBA) techniques (Particle Induced X-ray Emission, PIXE and Elastic Backscattering Spectrometry, EBS), were applied to investigate chloride and sulfate ions diffusion into laboratory prepared mortar samples. Development and characterization of an automated in-vacuum macro PIXE/EBS system is thoroughly discussed. Depth profile information of both chloride and sulfate ions in laboratory prepared mortar samples, after immersion in sea water for nine months, was rapidly and easily obtained at fairly low cost and with standardless analysis, demonstrating the value of the application of IBA to elemental depth profiling in cementitious materials. Chloride and sulfate depth profiles were obtained for two sets of mortar samples, one prepared with different water/cement (W/C) ratios and the other with different sand/cement (S/C) ratios. Results showed higher diffusion rates of both chloride and sulfate ions when both ratios are increased. Additionally, the W/C ratio has a stronger influence in both sulfate and chloride penetration than the S/C ratio, and chloride ions penetrate faster than sulfates. Advantages and limitations of applying IBA techniques in this investigation are discussed. The comparison between PIXE and other X-ray based analytical techniques, namely X-ray fluorescence (XRF) and energy and wavelength dispersive X-rays (EDX/WDX), as well as other traditional wet chemical methods is reviewed, and industrial applications are discussed.

VIBA-Lab 3.0: Computer program for simulation and semi-quantitative analysis of PIXE and RBS spectra and 2D elemental maps

NASA Astrophysics Data System (ADS)

Orlić, Ivica; Mekterović, Darko; Mekterović, Igor; Ivošević, Tatjana

2015-11-01

VIBA-Lab is a computer program originally developed by the author and co-workers at the National University of Singapore (NUS) as an interactive software package for simulation of Particle Induced X-ray Emission and Rutherford Backscattering Spectra. The original program is redeveloped to a VIBA-Lab 3.0 in which the user can perform semi-quantitative analysis by comparing simulated and measured spectra as well as simulate 2D elemental maps for a given 3D sample composition. The latest version has a new and more versatile user interface. It also has the latest data set of fundamental parameters such as Coster-Kronig transition rates, fluorescence yields, mass absorption coefficients and ionization cross sections for K and L lines in a wider energy range than the original program. Our short-term plan is to introduce routine for quantitative analysis for multiple PIXE and XRF excitations. VIBA-Lab is an excellent teaching tool for students and researchers in using PIXE and RBS techniques. At the same time the program helps when planning an experiment and when optimizing experimental parameters such as incident ions, their energy, detector specifications, filters, geometry, etc. By "running" a virtual experiment the user can test various scenarios until the optimal PIXE and BS spectra are obtained and in this way save a lot of expensive machine time.

The Determination of Soil-plant Transfer Coefficients of Cesium-137 and Other Elements by γ-Ray Measurement and PIXE Analysis, for use in the Remediation of Fukushima

NASA Astrophysics Data System (ADS)

Ishii, K.; Fujita, A.; Toyama, S.; Terakawa, A.; Matsuyama, S.; Arai, H.; Osada, N.; Takyu, S.; Matsuyama, T.; Koshio, S.; Watanabe, K.; Ito, S.; Kasahara, K.

Edible wild plants growing in the area around the Fukushima Daiichi nuclear power plant remain contaminated. It is important to identify plants with low levels of contamination for the restoration of agriculture in the area. We collected specimens of 10 wild plant species growing in Iitate village which is one of the most highly contaminated areas and also sampled the soil beneath each plant. We measured the specific activity of 137Cs and the concentrations of Na, Mg, Al, Si, P, S, K, Ca, Fe, Zn, Rb and Sr in these samples using a germanium detector and PIXE analysis, respectively. We compared the soil-plant transfer coefficient of 137Cs with those of each element and determined their correlation with 137Cs. It was found that a low Sr transfer coefficient could be used to determine the plants with a low 137Cs transfer coefficient. We suggest that PIXE analysis is a useful analysis technique for agricultural remediation projects in highly contaminated areas around the Fukushima Daiichi nuclear power plant.

Cadmium concentrations in the brains of Alzheimer cases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spyrou, N.M.; Stedman, J.D.

1996-12-31

There is ongoing research in relating the concentration of elements in the brain with Alzheimer`s disease. The presence of particular elements, such as aluminum and vanadium, has been considered as a possible environmental factor, creating significant interest and controversy in the field. We have been analyzing brain tissue from the MRC Alzheimer`s Disease Brain Bank, Institute of Psychiatry, from a number of cortical regions of the brain, namely, the frontal, occipital, parietal, and temporal lobes, as well as from the left and right hemispheres of the same brain whenever possible. The techniques employed have been proton-induced X-ray emission (PIXE) analysis,more » proton-induced gamma-ray emission (PIGE) analysis, Rutherford backscattering (RBS), and instrumental neutron activation analysis. Neutron irradiations were carried out at the Imperial College Consort II reactor, whereas for PIXE, PIGE, and RBS, the University of Surrey Accelerator Laboratories were used employing a Van de Graaff accelerator. In this paper, we present the cadmium results from the frontal lobe of Alzheimer cases and controls determined by PIXE analysis.« less

Dose distribution of a 125 keV mean energy microplanar x-ray beam for basic studies on microbeam radiotherapy.

PubMed

Ohno, Yumiko; Torikoshi, Masami; Suzuki, Masao; Umetani, Keiji; Imai, Yasuhiko; Uesugi, Kentaro; Yagi, Naoto

2008-07-01

A multislit collimator was designed and fabricated for basic studies on microbeam radiation therapy (MRT) with an x-ray energy of about 100 keV. It consists of 30 slits that are 25 microm high, 30 mm wide, and 5 mm thick in the beam direction. The slits were made of 25 microm-thick polyimide sheets that were separated by 175 microm-thick tungsten sheets. The authors measured the dose distribution of a single microbeam with a mean energy of 125 keV by a scanning slit method using a phosphor coupled to a charge coupled device camera and found that the ratios of the dose at the center of a microbeam to that at midpositions to adjacent slits were 1050 and 760 for each side of the microbeam. This dose distribution was well reproduced by the Monte Carlo simulation code PHITS.

The Elemental Analysis of Biological and Environmental Materials Using a 2MEV Proton Beam

NASA Astrophysics Data System (ADS)

Arshed, Waheed

Available from UMI in association with The British Library. A programme has been developed to simulate the proton induced x-ray emission (PIXE) spectra and its uses have been described. The PIXE technique has been applied to the analysis of new biological reference materials which consist of IAEA human diet samples and NIST leaf samples. Homogeneity of these and two existing reference materials, IAEA soil -7 and Bowen's kale, has also been determined at the mug scale. A subsample representative of a material is ascertained by determination of sampling factors for the elements detected in the material. Proton induced gamma-ray emission (PIGE) analysis in conjunction with PIXE has been employed to investigate F and other elemental concentrations found in human teeth samples. The mean F concentration in enamel and dentine parts of teeth followed an age dependent model. Concentrations of Ca and P were found to be higher in the enamel than in the dentine. Analysis of blood and its components in the study of elemental models in sickle cell disease in Nigerians has been carried out. Comparisons revealed that Cl, Ca and Cu were at higher levels whereas K, Fe, Zn and Rb were at lower levels in the whole blood of the sicklers compared to controls. Similar results were obtained for the erythrocytes except that Br was found at higher concentration in erythrocytes of the sicklers. Higher concentrations of Cl, K, Fe and Cu were also observed in plasma of the sicklers compared to controls. PIXE and scanning electron microscopy (SEM) were used in the characterization of the Harmattan dust particulates collected at Kano and Ife. Most of the elements were found to be at higher concentrations as compared to those found in Recife (Brazil) and Toronto (Canada). The value of total suspended particulate was above the relevant national air quality standards. PIXE in conjunction with Rutherford backscattering spectrometry and instrumental neutron activation analysis was employed in the analysis of soil samples detecting 31 elements. The results have been discussed with reference to elemental concentrations and Ca/Si ratio. The latter was a valid indicator of soil pollution by the cement dust. (Abstract shortened by UMI.).

Thermoelastic Damping in Cone Microcantilever Resonator

NASA Astrophysics Data System (ADS)

Li, Pu; Zhou, Hongyue

2017-07-01

Microbeams with continuous or discontinuous variable cross-section have been applied in Microelectromechanical Systems (MEMS) resonators, such as tapered microbeam, torsion microbeam and stepped microbeam. Thermoelastic damping (TED), which is verified as a fundamental energy lost mechanism for microresonators, is calculated by the Zener’s model and Lifshits and Roukes’s (LR) model in general. However, for non-uniform microbeam resonators, these two classical models are not suitable in some cases. On the basis of Zener’s theory, a TED model for cone microcantilever with rectangular cross-section has been derived in this study. The comparison of results obtained by the present model and Finite Element Method (FEM) model proves that the proposed model is able to predict TED value for cone microcantilever. In addition, TED in cone microcantilever is nearly same as TED in wedge microcantilever. The results show that quality factors (Q-factors) of cone microcantilever and wedge microcantilever are larger than Q-factor of uniform microbeam at low frequencies. The Debye peak value of a uniform microcantilever is equal to 0.5Δ E , while those of cone microcantilever and wedge microcantilever are about 0.438ΔE and 0.428ΔE, respectively.

New approaches for investigating paintings by ion beam techniques

NASA Astrophysics Data System (ADS)

Beck, L.; de Viguerie, L.; Walter, Ph.; Pichon, L.; Gutiérrez, P. C.; Salomon, J.; Menu, M.; Sorieul, S.

2010-06-01

Up to now, among the IBA techniques, only PIXE has been used for analyzing paintings. However, quantitative PIXE analysis is sometimes difficult to interpret due to the layered structure, the presence of varnish and organic binder and, in some cases, discoloration of the pigments has been observed due to the interaction of the ion beam with the compounds. In order to improve the characterization of paintings, we propose some alternative experimental procedures. First of all, backscattering spectrometry (BS) and PIXE are simultaneously combined in order to collect complementary information such as layer thickness and organic compound quantification. The simultaneous PIXE and BS experiments also have the advantage of being able to analyze the same area in one experiment. This combination, implemented with an external beam, was directly applied on paintings and on painting cross-sections for the study of Italian Renaissance masterpieces. We have obtained valuable results not only on the pigment itself but also, for the first time, on the binder to pigment proportion which is not well documented in the ancient recipes. Moreover, in order to restrain beam damages due to the ion stopping power, we propose to analyze very thin painting cross-sections by a combination of PIXE-RBS and Scanning Transmission Ion Microscopy (STIM).

Effects of microbeam radiation therapy on normal and tumoral blood vessels.

PubMed

Bouchet, Audrey; Serduc, Raphäel; Laissue, Jean Albert; Djonov, Valentin

2015-09-01

Microbeam radiation therapy (MRT) is a new form of preclinical radiotherapy using quasi-parallel arrays of synchrotron X-ray microbeams. While the deposition of several hundred Grays in the microbeam paths, the normal brain tissues presents a high tolerance which is accompanied by the permanence of apparently normal vessels. Conversely, the efficiency of MRT on tumor growth control is thought to be related to a preferential damaging of tumor blood vessels. The high resistance of the healthy vascular network was demonstrated in different animal models by in vivo biphoton microscopy, magnetic resonance imaging, and histological studies. While a transient increase in permeability was shown, the structure of the vessels remained intact. The use of a chick chorioallantoic membrane at different stages of development showed that the damages induced by microbeams depend on vessel maturation. In vivo and ultrastructural observations showed negligible effects of microbeams on the mature vasculature at late stages of development; nevertheless a complete destruction of the immature capillary plexus was found in the microbeam paths. The use of MRT in rodent models revealed a preferential effect on tumor vessels. Although no major modification was observed in the vasculature of normal brain tissue, tumors showed a denudation of capillaries accompanied by transient increased permeability followed by reduced tumor perfusion and finally, a decrease in number of tumor vessels. Thus, MRT is a very promising treatment strategy with pronounced tumor control effects most likely based on the anti-vascular effects of MRT. Copyright © 2015. Published by Elsevier Ltd.

High energy PIXE: A tool to characterize multi-layer thick samples

NASA Astrophysics Data System (ADS)

Subercaze, A.; Koumeir, C.; Métivier, V.; Servagent, N.; Guertin, A.; Haddad, F.

2018-02-01

High energy PIXE is a useful and non-destructive tool to characterize multi-layer thick samples such as cultural heritage objects. In a previous work, we demonstrated the possibility to perform quantitative analysis of simple multi-layer samples using high energy PIXE, without any assumption on their composition. In this work an in-depth study of the parameters involved in the method previously published is proposed. Its extension to more complex samples with a repeated layer is also presented. Experiments have been performed at the ARRONAX cyclotron using 68 MeV protons. The thicknesses and sequences of a multi-layer sample including two different layers of the same element have been determined. Performances and limits of this method are presented and discussed.

c-Cbl regulates αPix-mediated cell migration and invasion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seong, Min Woo; Park, Ji Ho; Yoo, Hee Min

2014-12-12

Highlights: • c-Cbl ubiquitinates αPix for proteasome-mediated degradation. • C6 and A172 glioma cells lack c-Cbl, which leads to stabilization of αPix. • The accumulated αPix promotes migration and invasion of the cancer cells. • The lack of c-Cbl in the cells appears responsible for their malignant behavior. - Abstract: c-Cbl, a RING-type ubiquitin E3 ligase, down-regulates receptor tyrosine kinases, including EGF receptor, and inhibits cell proliferation. Moreover, c-Cbl mutations are frequently found in patients with myeloid neoplasm. Therefore, c-Cbl is known as a tumor suppressor. αPix is expressed only in highly proliferative and mobile cells, including immune cells, andmore » up-regulated in certain invasive tumors, such as glioblastoma multiforme. Here, we showed that c-Cbl serves as an ubiquitin E3 ligase for proteasome-mediated degradation of αPix, but not βPix. Remarkably, the rat C6 and human A172 glioma cells were unable to express c-Cbl, which leads to a dramatic accumulation of αPix. Depletion of αPix by shRNA markedly reduced the ability of the glioma cells to migrate and invade, whereas complementation of shRNA-insensitive αPix promoted it. These results indicate that c-Cbl negatively regulates αPix-mediated cell migration and invasion and the lack of c-Cbl in the C6 and A172 glioma cells is responsible for their malignant behavior.« less

Future of ePix detectors for high repetition rate FELs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blaj, G., E-mail: blaj@slac.stanford.edu; Caragiulo, P.; Carini, G.

2016-07-27

Free-electron lasers (FELs) made the imaging of atoms and molecules in motion possible, opening new science opportunities with high brilliance, ultra-short x-ray laser pulses at up to 120 Hz. Some new or upgraded FEL facilities will operate at greatly increased pulse rates (kHz to MHz), presenting additional requirements on detection. We will present the ePix platform for x-ray detectors and the current status of the ePix detectors: ePix100 for low noise applications, ePix10k for high dynamic range applications, and ePixS for spectroscopic applications. Then we will introduce the plans to match the ePix detectors with the requirements of currently plannedmore » high repetition rate FELs (mainly readout speed and energy range).« less

Endothelin-1 Inhibits the Epithelial Na+ Channel through βPix/14-3-3/Nedd4-2

PubMed Central

Pavlov, Tengis S.; Chahdi, Ahmed; Ilatovskaya, Daria V.; Levchenko, Vladislav; Vandewalle, Alain; Pochynyuk, Oleh

2010-01-01

Epithelial Na+ channels (ENaCs) mediate sodium reabsorption in the cortical collecting duct (CCD), but the regulatory pathways that modulate the activity of these channels are incompletely understood. Here, we observed that endothelin-1 (ET-1) attenuates ENaC activity acutely by reducing the channel's open probability and chronically by decreasing the number of channels in the plasma membrane. To investigate whether β1Pix, a signaling protein activated by ET-1, mediates ENaC activity, we reconstituted ENaC in CHO cells with or without coexpressed β1Pix and found that β1Pix negatively regulates ENaC. Knockdown of βPix in native principal cells abolished the ET-1-induced decrease in ENaC channel number. Furthermore, we found that βPix does not decrease ENaC activity through its guanine nucleotide exchange factor (GEF) activity for Rac1 and Cdc42. Instead, coexpression of β1Pix mutant constructs revealed that β1Pix affects ENaC activity through binding 14-3-3 proteins. Coimmunoprecipitation experiments supported a physical interaction between β1Pix and 14-3-3β in cultured principal cells. Coexpression of 14-3-3β increased ENaC activity in CHO cells, but concomitant expression of β1Pix attenuated this increase. Recruitment of 14-3-3β by β1Pix impaired the interaction of 14-3-3β with the ubiquitin ligase Nedd4-2, thereby promoting ubiquitination and degradation of ENaC. Taken together, these results suggest that the inhibitory effects of chronic ET-1 on ENaC result from βPix interacting with the 14-3-3/Nedd4-2 pathway. PMID:20338996

PIXE analysis on Maya blue in Prehispanic and colonial mural paintings

NASA Astrophysics Data System (ADS)

Sánchez del Río, M.; Martinetto, P.; Solís, C.; Reyes-Valerio, C.

2006-08-01

Particle induced X-ray emission (PIXE) experiments have been carried out at the AGLAE facility (Paris) on several mural samples containing Maya blue from different Prehispanic archaeological sites (Cacaxtla, El Tajín, Tamuin, Santa Cecilia Acatitlán) and from several colonial convents in the Mexican plateau (Jiutepec, Totimehuacán, Tezontepec and Cuauhtinchán). The analysis of the concentration of several elements permitted to extract some information on the technique used for painting the mural, usually fresco. Principal component analysis permitted to classify the samples into groups. This grouping is discussed in relation to geographic and historic data.

Live cell imaging at the Munich ion microbeam SNAKE - a status report.

PubMed

Drexler, Guido A; Siebenwirth, Christian; Drexler, Sophie E; Girst, Stefanie; Greubel, Christoph; Dollinger, Günther; Friedl, Anna A

2015-02-18

Ion microbeams are important tools in radiobiological research. Still, the worldwide number of ion microbeam facilities where biological experiments can be performed is limited. Even fewer facilities combine ion microirradiation with live-cell imaging to allow microscopic observation of cellular response reactions starting very fast after irradiation and continuing for many hours. At SNAKE, the ion microbeam facility at the Munich 14 MV tandem accelerator, a large variety of biological experiments are performed on a regular basis. Here, recent developments and ongoing research projects at the ion microbeam SNAKE are presented with specific emphasis on live-cell imaging experiments. An overview of the technical details of the setup is given, including examples of suitable biological samples. By ion beam focusing to submicrometer beam spot size and single ion detection it is possible to target subcellular structures with defined numbers of ions. Focusing of high numbers of ions to single spots allows studying the influence of high local damage density on recruitment of damage response proteins.

Dose distribution of a 125 keV mean energy microplanar x-ray beam for basic studies on microbeam radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohno, Yumiko; Torikoshi, Masami; Suzuki, Masao

A multislit collimator was designed and fabricated for basic studies on microbeam radiation therapy (MRT) with an x-ray energy of about 100 keV. It consists of 30 slits that are 25 {mu}m high, 30 mm wide, and 5 mm thick in the beam direction. The slits were made of 25 {mu}m-thick polyimide sheets that were separated by 175 {mu}m-thick tungsten sheets. The authors measured the dose distribution of a single microbeam with a mean energy of 125 keV by a scanning slit method using a phosphor coupled to a charge coupled device camera and found that the ratios of themore » dose at the center of a microbeam to that at midpositions to adjacent slits were 1050 and 760 for each side of the microbeam. This dose distribution was well reproduced by the Monte Carlo simulation code PHITS.« less

PIXE analysis of mineral matter in thin sections of human lung

NASA Astrophysics Data System (ADS)

Annegarn, H. J.; Pillay, A. E.; Da Vies, J. C. A.; Faure, D.; Sellschop, J. P. F.

1988-12-01

It is postulated that insoluble mineral residues in the lungs of deceased miners may provide a quantitative measure of the integrated lifetime dust exposure. For epidemiological surveys rapid instrumental techniques are required to analyse representative samples of lung tissue. Particle-induced X-ray emission (PIXE) has been evaluated for analysis of microtomed slices of wax-embedded lung and lymph node (Hilar gland) tissue from deceased miners. The 50 μm slices, mounted on Mylar backings and placed in a He atmosphere, were irradiated using 3.2 MeV protons. PIXE analysis provided adequate sensitivity for key mineral elements including Si, Cr and Ti. The porous, nonuniform nature of lung tissue made it impossible to measure the tissue mass in the irradiated area, preventing the calculation of mass concentrations. Instead, biological sulphur was used as an internal standard, assuming that the fraction of S in soft, fat-free tissue is constant. Results are presented for lung and lymph node tissue from gold, chrome, copper, platinum and asbestos miners. Si mineral residues in lymph node tissue were found to be concentrated by a factor 50 relative to lung. Cr residues were clearly observed in the chrome miner's lung, but no excess of Cu was present in the copper miner's lung. There is evidence of preferential Si removal relative to Ti. Results warrant further development of PIXE for scanning of large numbers of lung samples prepared in the above manner.

X-ray microbeam measurements with a high resolution scintillator fibre-optic dosimeter.

PubMed

Archer, James; Li, Enbang; Petasecca, Marco; Dipuglia, Andrew; Cameron, Matthew; Stevenson, Andrew; Hall, Chris; Hausermann, Daniel; Rosenfeld, Anatoly; Lerch, Michael

2017-09-29

Synchrotron microbeam radiation therapy is a novel external beam therapy under investigation, that uses highly brilliant synchrotron x-rays in microbeams 50 μm width, with separation of 400 μm, as implemented here. Due to the fine spatial fractionation dosimetry of these beams is a challenging and complicated problem. In this proof-of-concept work, we present a fibre optic dosimeter that uses plastic scintillator as the radiation conversion material. We claim an ideal one-dimensional resolution of 50 μm. Using plastic scintillator and fibre optic makes this dosimeter water-equivalent, a very desirable dosimetric property. The dosimeter was tested at the Australian Synchrotron, on the Imaging and Medical Beam-Line. The individual microbeams were able to be resolved and the peak-to-valley dose ratio and the full width at half maximum of the microbeams was measured. These results are compared to a semiconductor strip detector of the same spatial resolution. A percent depth dose was measured and compared to data acquired by an ionisation chamber. The results presented demonstrate significant steps towards the development of an optical dosimeter with the potential to be applied in quality assurance of microbeam radiation therapy, which is vital if clinical trials are to be performed on human patients.

Chloroplasts do not have a polarity for light-induced accumulation movement.

PubMed

Tsuboi, Hidenori; Yamashita, Hiroko; Wada, Masamitsu

2009-01-01

Chloroplast photorelocation movement in green plants is generally mediated by blue light. However, in cryptogam plants, including ferns, mosses, and algae, both red light and blue light are effective. Although the photoreceptors required for this phenomenon have been identified, the mechanisms underlying this movement response are not yet known. In order to analyze this response in more detail, chloroplast movement was induced in dark-adapted Adiantum capillus-veneris gametophyte cells by partial cell irradiation with a microbeam of red and/or blue light. In each case, chloroplasts were found to move toward the microbeam-irradiated area. A second microbeam was also applied to the cell at a separate location before the chloroplasts had reached the destination of the first microbeam. Under these conditions, chloroplasts were found to change their direction of movement without turning and move toward the second microbeam-irradiated area after a lag time of a few minutes. These findings indicate that chloroplasts can move in any direction and do not exhibit a polarity for chloroplast accumulation movement. This phenomenon was analyzed in detail in Adiantum and subsequently confirmed in Arabidopsis thaliana palisade cells. Interestingly, the lag time for direction change toward the second microbeam in Adiantum was longer in the red light than in the blue light. However, the reason for this discrepancy is not yet understood.

Trace-Element Analysis by Use of PIXE Technique on Agricultural Products

NASA Astrophysics Data System (ADS)

Takagi, A.; Yokoyama, R.; Makisaka, K.; Kisamori, K.; Kuwada, Y.; Nishimura, D.; Matsumiya, R.; Fujita, Y.; Mihara, M.; Matsuta, K.; Fukuda, M.

2009-10-01

In order to examine whether a trace-element analysis by PIXE (Particle Induced X-ray Emission) gives a clue to identify production area of agricultural products, we carried out a study on soy beans as an example. In the present study, a proton beam at the energy of 2.3MeV was provided by Van de Graaff accelerator at Osaka University. We used a Ge detector with Be window to measure X-ray spectra. We prepared sample soy beans from China, Thailand, Taiwan, and 7 different areas in Japan. As a result of PIXE analysis, 5 elements, potassium, iron, zinc, arsenic and rubidium, have been identified. There are clear differences in relative amount of trace-elements between samples from different international regions. Chinese beans contain much more Rb than the others, while there are significant differences in Fe and Zn between beans of Thailand and Taiwan. There are relatively smaller differences among Japanese beans. This result shows that trace-elements bring us some practical information of the region where the product grown.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hichwa, B.P.; Pun, D.D.; Wang, D.

A multielemental analysis to determine the trace metal content of generic and name-brand aspirins and name-brand lipsticks was done via proton induced x-ray (PIXE) measurements. The Hope College PIXE system is described as well as the target preparation methods. The trace metal content of twelve brands of aspirin and aspirin substitutes and fourteen brands of lipstick are reported. Detection limits for most elements are in the range of 100 parts per billion (ppb) to 10 parts per million (ppm).

mRNA Expression Profiling of Laser Microbeam Microdissected Cells from Slender Embryonic Structures

PubMed Central

Scheidl, Stefan J.; Nilsson, Sven; Kalén, Mattias; Hellström, Mats; Takemoto, Minoru; Håkansson, Joakim; Lindahl, Per

2002-01-01

Microarray hybridization has rapidly evolved as an important tool for genomic studies and studies of gene regulation at the transcriptome level. Expression profiles from homogenous samples such as yeast and mammalian cell cultures are currently extending our understanding of biology, whereas analyses of multicellular organisms are more difficult because of tissue complexity. The combination of laser microdissection, RNA amplification, and microarray hybridization has the potential to provide expression profiles from selected populations of cells in vivo. In this article, we present and evaluate an experimental procedure for global gene expression analysis of slender embryonic structures using laser microbeam microdissection and laser pressure catapulting. As a proof of principle, expression profiles from 1000 cells in the mouse embryonic (E9.5) dorsal aorta were generated and compared with profiles for captured mesenchymal cells located one cell diameter further away from the aortic lumen. A number of genes were overexpressed in the aorta, including 11 previously known markers for blood vessels. Among the blood vessel markers were endoglin, tie-2, PDGFB, and integrin-β1, that are important regulators of blood vessel formation. This demonstrates that microarray analysis of laser microbeam micro-dissected cells is sufficiently sensitive for identifying genes with regulative functions. PMID:11891179

WE-AB-BRB-12: Nanoscintillator Fiber-Optic Detector System for Microbeam Radiation Therapy Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivera, J; Dooley, J; Chang, S

2015-06-15

Purpose: Microbeam Radiation Therapy (MRT) is an experimental radiation therapy that has demonstrated a higher therapeutic ratio than conventional radiation therapy in animal studies. There are several roadblocks in translating the promising treatment technology to clinical application, one of which is the lack of a real-time, high-resolution dosimeter. Current clinical radiation detectors have poor spatial resolution and, as such, are unsuitable for measuring microbeams with submillimeter-scale widths. Although GafChromic film has high spatial resolution, it lacks the real-time dosimetry capability necessary for MRT preclinical research and potential clinical use. In this work we have demonstrated the feasibility of using amore » nanoscintillator fiber-optic detector (nanoFOD) system for real-time MRT dosimetry. Methods: A microplanar beam array is generated using a x-ray research irradiator and a custom-made, microbeam-forming collimator. The newest generation nanoFOD has an effective size of 70 µm in the measurement direction and was calibrated against a kV ion chamber (RadCal Accu-Pro) in open field geometry. We have written a computer script that performs automatic data collection with immediate background subtraction. A computer-controlled detector positioning stage is used to precisely measure the microbeam peak dose and beam profile by translating the stage during data collection. We test the new generation nanoFOD system, with increased active scintillation volume, against the previous generation system. Both raw and processed data are time-stamped and recorded to enable future post-processing. Results: The real-time microbeam dosimetry system worked as expected. The new generation dosimeter has approximately double the active volume compared to the previous generation resulting in over 900% increase in signal. The active volume of the dosimeter still provided the spatial resolution that meets the Nyquist criterion for our microbeam widths. Conclusion: We have demonstrated that real-time dosimetry of MRT microbeams is feasible using a nanoscintillator fiber-optic detector with integrated positioning system.« less

DeltaPhage—a novel helper phage for high-valence pIX phagemid display

PubMed Central

Nilssen, Nicolay R.; Frigstad, Terje; Pollmann, Sylvie; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger; Løset, Geir Å.

2012-01-01

Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades. We recently reported a novel pIX phagemid display system that is characterized by a strong preference for phagemid packaging combined with low display levels, two key features that support highly efficient affinity selection. However, high diversity in selected repertoires are intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage termed DeltaPhage that allows for high-valence display on pIX. This was obtained by inserting two amber mutations close to the pIX start codon, but after the pVII translational stop, conditionally inactivating the helper phage encoded pIX. Until now, the general notion has been that display on pIX is dependent on wild-type complementation, making high-valence display unachievable. However, we found that DeltaPhage does facilitate high-valence pIX display when used with a non-suppressor host. Here, we report a side-by-side comparison with pIII display, and we find that this novel helper phage complements existing pIX phagemid display systems to allow both low and high-valence display, making pIX display a complete and efficient alternative to existing pIII phagemid display systems. PMID:22539265

DeltaPhage--a novel helper phage for high-valence pIX phagemid display.

PubMed

Nilssen, Nicolay R; Frigstad, Terje; Pollmann, Sylvie; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger; Løset, Geir Å

2012-09-01

Phage display has been instrumental in discovery of novel binding peptides and folded domains for the past two decades. We recently reported a novel pIX phagemid display system that is characterized by a strong preference for phagemid packaging combined with low display levels, two key features that support highly efficient affinity selection. However, high diversity in selected repertoires are intimately coupled to high display levels during initial selection rounds. To incorporate this additional feature into the pIX display system, we have developed a novel helper phage termed DeltaPhage that allows for high-valence display on pIX. This was obtained by inserting two amber mutations close to the pIX start codon, but after the pVII translational stop, conditionally inactivating the helper phage encoded pIX. Until now, the general notion has been that display on pIX is dependent on wild-type complementation, making high-valence display unachievable. However, we found that DeltaPhage does facilitate high-valence pIX display when used with a non-suppressor host. Here, we report a side-by-side comparison with pIII display, and we find that this novel helper phage complements existing pIX phagemid display systems to allow both low and high-valence display, making pIX display a complete and efficient alternative to existing pIII phagemid display systems.

X-ray microbeam three-dimensional topography for dislocation strain-field analysis of 4H-SiC

NASA Astrophysics Data System (ADS)

Tanuma, R.; Mori, D.; Kamata, I.; Tsuchida, H.

2013-07-01

This paper describes the strain-field analysis of threading edge dislocations (TEDs) and basal-plane dislocations (BPDs) in 4H-SiC using x-ray microbeam three-dimensional (3D) topography. This 3D topography enables quantitative strain-field analysis, which measures images of effective misorientations (Δω maps) around the dislocations. A deformation-matrix-based simulation algorithm is developed to theoretically evaluate the Δω mapping. Systematic linear calculations can provide simulated Δω maps (Δωsim maps) of dislocations with different Burgers vectors, directions, and reflection vectors for the desired cross-sections. For TEDs and BPDs, Δω maps are compared with Δωsim maps, and their excellent correlation is demonstrated. Two types of asymmetric reflections, high- and low-angle incidence types, are compared. Strain analyses are also conducted to investigate BPD-TED conversion near an epilayer/substrate interface in 4H-SiC.

Elemental investigation of Syrian medicinal plants using PIXE analysis

NASA Astrophysics Data System (ADS)

Rihawy, M. S.; Bakraji, E. H.; Aref, S.; Shaban, R.

2010-09-01

Particle induced X-ray emission (PIXE) technique has been employed to perform elemental analysis of K, Ca, Mn, Fe, Cu, Zn, Br and Sr for Syrian medicinal plants used traditionally to enhance the body immunity. Plant samples were prepared in a simple dried base. The results were verified by comparing with those obtained from both IAEA-359 and IAEA-V10 reference materials. Relative standard deviations are mostly within ±5-10% suggest good precision. A correlation between the elemental content in each medicinal plant with its traditional remedial usage has been proposed. Both K and Ca are found to be the major elements in the samples. Fe, Mn and Zn have been detected in good levels in most of these plants clarifying their possible contribution to keep the body immune system in good condition. The contribution of the elements in these plants to the dietary recommended intakes (DRI) has been evaluated. Advantages and limitations of PIXE analytical technique in this investigation have been reviewed.

Total elemental composition of soils contaminated with wastewater irrigation by combining IBA techniques

NASA Astrophysics Data System (ADS)

Huerta, L.; Contreras-Valadez, R.; Palacios-Mayorga, S.; Miranda, J.; Calva-Vasquez, G.

2002-04-01

The purpose of this work was to obtain the total elemental composition of agricultural soils irrigated with well water and wastewater. The studied area is located in the Valle del Mezquital in Hidalgo State, Mexico. The studied soils were collected, every two months during one year. Particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA) were applied for elemental analysis. PIXE analyses gave elemental contents of major and trace elements (Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Br, Rb, Sr, Y, Zr, and Pb). Total concentrations of Na, Mg, C, N and O were obtained by RBS and NRA. PIXE analyses were carried out with 2 MeV proton beams, RBS with 2 MeV helium ions, while NRA was applied with a 1.2 MeV deuterium beam. Results indicated that heavy metal total concentrations exceed the critical soil total concentrations according to environmental regulations.

PIGE-PIXE analysis of human milk

NASA Astrophysics Data System (ADS)

Olabanji, S. O.; Buoso, M. C.; Ceccato, D.; Haque, A. M. I.; Cherubini, R.; Moschini, G.

1996-04-01

PIGE-PIXE nuclear techniques were employed for the determination of the elemental composition of human breast milk which is the main source of nutrients to babies in Nigeria. Samples were collected from 32 healthy lactating mothers from Obafemi Awolowo Teaching University Hospital, Ile-Ife, Nigeria. The samples were homogenized and immediately frozen, and then freeze-dried. Pellets were made using a Perkin Elmer instrument and its accessory the 13 mm die. PIGE measurements of light elements were performed using 3.5 MeV collimated protons from the 7 MV CN Van de Graaff accelerator of INFN, LNL, Legnaro (Padova) Italy while PIXE analysis was carried out using 1.8 MeV collimated proton beam from the 2.5 MV AN 2000 Van de Graaff accelerator of the same Institute. The results show the presence of important elements that are essential for growth and development of babies. We searched for certain toxic elements which include As, Cd, Hg, Pb, etc. because of their negative roles in enhancing infant mortality rates, but none of them was detected except Pb.

PIXE analysis of ancient Chinese Changsha porcelain

NASA Astrophysics Data System (ADS)

Lin, E. K.; Yu, Y. C.; Wang, C. W.; Liu, T. Y.; Wu, C. M.; Chen, K. M.; Lin, S. S.

1999-04-01

In this work, proton induced X-ray emission (PIXE) method was applied for the analysis of ancient Chinese Changsha porcelain produced in the Tang dynasty (AD 618-907). A collection of glazed potsherds was obtained in the complex of the famous kiln site at Tongguan, Changsha city, Hunan province. Studies of elemental composition were carried out on ten selected Changsha potsherds. Minor and trace elements such as Ti, Mn, Fe, Co, Cu, Rb, Sr, and Zr in the material of the porcelain glaze were determined. Variation of these elements from sample to sample was investigated. Details of results are presented and discussed.

RBS and PIXE analysis of chlorine contamination in ALD-Grown TiN films on silicon

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meersschaut, J.; Witters, T.; Kaeyhkoe, M.

2013-04-19

The performance, strengths and limitations of RBS and PIXE for the characterization of trace amounts of Cl in TiN thin films are critically compared. The chlorine atomic concentration in ALD grown TiN thin films on Si is determined for samples grown at temperatures ranging from 350 Degree-Sign C to 550 Degree-Sign C. We show that routine Rutherford backscattering spectrometry measurements (1.5 MeV He{sup +}) and PIXE measurements (1.5 MeV H{sup +}) on 20 nm thick TiN films allow one to determine the Cl content down to 0.3 at% with an absolute statistical accuracy reaching 0.03 at%. Possible improvements to pushmore » the sensitivity limit for both approaches are proposed.« less

High Resolution Electron Microbeam Examination and 3D Reconstruction of Alligator Gar Scale

DTIC Science & Technology

2016-06-27

Distribution Unlimited UU UU UU UU 27-06-2016 15-Nov-2012 14-Nov-2015 Final Report: High Resolution Electron Microbeam Examination and 3D ...ADDRESS (ES) U.S. Army Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 Alligator Gar Fish, 3D characterization, Electron...Resolution Electron Microbeam Examination and 3D reconstruction of Alligator Gar Scale Report Title Engineered laminate composites have been widely used

Composition of Renaissance paint layers: simultaneous particle induced X-ray emission and backscattering spectrometry.

PubMed

de Viguerie, L; Beck, L; Salomon, J; Pichon, L; Walter, Ph

2009-10-01

Particle induced X-ray emission spectroscopy (PIXE) is now routinely used in the field of cultural heritage. Various setups have been developed to investigate the elemental composition of wood/canvas paintings or of cross-section samples. However, it is not possible to obtain information concerning the quantity of organic binder. Backscattering spectrometry (BS) can be a useful complementary method to overcome this limitation. In the case of paint layers, PIXE brings the elemental composition (major elements to traces) and the BS spectrum can give access to the proportion of pigment and binder. With the use of 3 MeV protons for PIXE and BS simultaneously, it was possible to perform quantitative analysis including C and O for which the non-Rutherford cross sections are intense. Furthermore, with the use of the same conditions for PIXE and BS, the experiment time and the potential damage by the ion beam were reduced. The results obtained with the external beam of the Accélérateur Grand Louvre pour l'Analyse Elementaire (AGLAE) facility on various test painting samples and on cross sections from Italian Renaissance masterpieces are shown. Simultaneous combination of PIXE and BS leads to a complete characterization of the paint layers: elemental composition and proportion of the organic binder have been determined and thus provide useful information about ancient oil painting recipes.

Vibration analysis of rotating functionally graded Timoshenko microbeam based on modified couple stress theory under different temperature distributions

NASA Astrophysics Data System (ADS)

Ghadiri, Majid; Shafiei, Navvab

2016-04-01

In this study, thermal vibration of rotary functionally graded Timoshenko microbeam has been analyzed based on modified couple stress theory considering temperature change in four types of temperature distribution on thermal environment. Material properties of FG microbeam are supposed to be temperature dependent and vary continuously along the thickness according to the power-law form. The axial forces are also included in the model as the thermal and true spatial variation due to the rotation. Governing equations and boundary conditions have been derived by employing Hamiltonian's principle. The differential quadrature method is employed to solve the governing equations for cantilever and propped cantilever boundary conditions. Validations are done by comparing available literatures and obtained results which indicate accuracy of applied method. Results represent effects of temperature changes, different boundary conditions, nondimensional angular velocity, length scale parameter, different boundary conditions, FG index and beam thickness on fundamental, second and third nondimensional frequencies. Results determine critical values of temperature changes and other essential parameters which can be applicable to design micromachines like micromotor and microturbine.

Automated microbeam observation environment for biological analysis—Custom portable environmental control applied to a vertical microbeam system

PubMed Central

England, Matthew J.; Bigelow, Alan W.; Merchant, Michael J.; Velliou, Eirini; Welch, David; Brenner, David J.; Kirkby, Karen J.

2018-01-01

Vertical Microbeams (VMB) are used to irradiate individual cells with low MeV energy ions. The irradiation of cells using VMBs requires cells to be removed from an incubator; this can cause physiological changes to cells because of the lower CO2 concentration, temperature and relative humidity outside of the incubator. Consequently, for experiments where cells require irradiation and observation for extended time periods, it is important to provide a controlled environment. The highly customised nature of the microscopes used on VMB systems means that there are no commercially available environmentally controlled microscope systems for VMB systems. The Automated Microbeam Observation Environment for Biological Analysis (AMOEBA) is a highly flexible modular environmental control system used to create incubator conditions on the end of a VMB. The AMOEBA takes advantage of the recent “maker” movement to create an open source control system that can be easily configured by the user to fit their control needs even beyond VMB applications. When applied to the task of controlling cell medium temperature, CO2 concentration and relative humidity on VMBs it creates a stable environment that allows cells to multiply on the end of a VMB over a period of 36 h, providing a low-cost (costing less than $2700 to build), customisable alternative to commercial time-lapse microscopy systems. AMOEBA adds the potential of VMBs to explore the long-term effects of radiation on single cells opening up new research areas for VMBs. PMID:29515291

PIXE analysis of Thaumatococcus danielli in Osun State of Nigeria

NASA Astrophysics Data System (ADS)

Olabanji, S. O.; Osinkolu, G. A.; Pelemo, D. A.; Obiajunwa, E. I.; Oladele, A. T.

2014-01-01

Particle-induced X-ray emission (PIXE) technique was employed for the determination of elemental compositions of Thaumatococcus danielli (T. danielli) {Marantaceae} (Benn.) Benth [miraculous berry] in Osun State of Nigeria. The objective is to show the usefulness of T. danielli and especially the beneficial effects of the mineral concentrations from the leaves and fruits of T. danielli. The results show the detection of seventeen elements at different concentrations, and their beneficial effects to humans were discussed.

Fiber-optic detector for real time dosimetry of a micro-planar x-ray beam

PubMed Central

Belley, Matthew D.; Stanton, Ian N.; Hadsell, Mike; Ger, Rachel; Langloss, Brian W.; Lu, Jianping; Zhou, Otto; Chang, Sha X.; Therien, Michael J.; Yoshizumi, Terry T.

2015-01-01

Purpose: Here, the authors describe a dosimetry measurement technique for microbeam radiation therapy using a nanoparticle-terminated fiber-optic dosimeter (nano-FOD). Methods: The nano-FOD was placed in the center of a 2 cm diameter mouse phantom to measure the deep tissue dose and lateral beam profile of a planar x-ray microbeam. Results: The continuous dose rate at the x-ray microbeam peak measured with the nano-FOD was 1.91 ± 0.06 cGy s−1, a value 2.7% higher than that determined via radiochromic film measurements (1.86 ± 0.15 cGy s−1). The nano-FOD-determined lateral beam full-width half max value of 420 μm exceeded that measured using radiochromic film (320 μm). Due to the 8° angle of the collimated microbeam and resulting volumetric effects within the scintillator, the profile measurements reported here are estimated to achieve a resolution of ∼0.1 mm; however, for a beam angle of 0°, the theoretical resolution would approach the thickness of the scintillator (∼0.01 mm). Conclusions: This work provides proof-of-concept data and demonstrates that the novel nano-FOD device can be used to perform real-time dosimetry in microbeam radiation therapy to measure the continuous dose rate at the x-ray microbeam peak as well as the lateral beam shape. PMID:25832087

Micro X-ray diffraction analysis of thin films using grazing-exit conditions.

PubMed

Noma, T; Iida, A

1998-05-01

An X-ray diffraction technique using a hard X-ray microbeam for thin-film analysis has been developed. To optimize the spatial resolution and the surface sensitivity, the X-ray microbeam strikes the sample surface at a large glancing angle while the diffracted X-ray signal is detected with a small (grazing) exit angle. Kirkpatrick-Baez optics developed at the Photon Factory were used, in combination with a multilayer monochromator, for focusing X-rays. The focused beam size was about 10 x 10 micro m. X-ray diffraction patterns of Pd, Pt and their layered structure were measured. Using a small exit angle, the signal-to-background ratio was improved due to a shallow escape depth. Under the grazing-exit condition, the refraction effect of diffracted X-rays was observed, indicating the possibility of surface sensitivity.

Quantitative Single-Ion Irradiation by ASIPP Microbeam

NASA Astrophysics Data System (ADS)

Wang, Xu-Fei; Chen, Lian-Yun; Hu, Zhi-Wen; Wang, Xiao-Hua; Zhang, Jun; Li, Jun; Chen, Bin; Hu, Su-Hua; Shi, Zhong-Tao; Wu, Yu; Xu, Ming-Liang; Wu, Li-Jun; Wang, Shao-Hu; Yu, Zeng-Liang

2004-05-01

A single-ion microbeam facility has been constructed by the microbeam research group in ASIPP (Institute of Plasma Physics, Chinese Academy of Science). The system was designed to deliver defined numbers of hydrogen ions produced by a van de Graaff accelerator, covering an energy range from 200 keV to 3 MeV, into living cells (5 mum-20 mum diameter) growing in culture on thin plastic films. The beam is collimated by a 1- mum inner diameter HPLC (high performance liquid chromatography) capillary, which forms the micron-dimensional beam-line exit. A microbeam collimator, a scintillation ion counting system and a fast beam shutter, which constitute a precise dosage measuring and controlling system, jointly perform quantitative single-ion irradiation. With this facility, we can presently acquire ion-hitting efficiency close to 95%.

A new small-footprint external-beam PIXE facility for cultural heritage applications using pulsed proton beams

NASA Astrophysics Data System (ADS)

Vadrucci, M.; Bazzano, G.; Borgognoni, F.; Chiari, M.; Mazzinghi, A.; Picardi, L.; Ronsivalle, C.; Ruberto, C.; Taccetti, F.

2017-09-01

In the framework of the COBRA project, elemental analyses of cultural heritage objects based on the particle induced X-ray emission (PIXE) are planned in a collaboration between the APAM laboratory of ENEA-Frascati and the LABEC laboratory of INFN in Florence. With this aim a 3-7 MeV pulsed proton beam, driven by the injector of the protontherapy accelerator under construction for the TOP-IMPLART project, will be used to demonstrate the feasibility of the technique with a small-footprint pulsed accelerator to Italian small and medium enterprises interested in the composition analysis of ancient artifacts. The experimental set-up for PIXE analysis on the TOP-IMPLART machine consists of a modified assembly of the vertical beam line usually dedicated to radiobiology experiments: the beam produced by the injector (RFQ + DTL, a PL7 ACCSYSHITACHI model) is bent to 90° by a magnet, is collimated by a 300 μm aperture inserted in the end nozzle and extracted into ambient pressure by an exit window consisting of a Upilex foil 7.5 μm thick. The beam is pulsed with a variable pulse duration of 20-100 μs and a repetition rate variable from 10 to 100 Hz. The X-ray detection system is based on a Ketek Silicon Drift Detector (SDD) with 7 mm2 active area and 450 μm thickness, with a thin Beryllium entrance window (8 μm). The results of the calibration of this new PIXE set-up using thick target standards and of the analysis of the preliminary measurements on pigments are presented.

Optimizing total reflection X-ray fluorescence for direct trace element quantification in proteins I: Influence of sample homogeneity and reflector type

NASA Astrophysics Data System (ADS)

Wellenreuther, G.; Fittschen, U. E. A.; Achard, M. E. S.; Faust, A.; Kreplin, X.; Meyer-Klaucke, W.

2008-12-01

Total reflection X-ray fluorescence (TXRF) is a very promising method for the direct, quick and reliable multi-elemental quantification of trace elements in protein samples. With the introduction of an internal standard consisting of two reference elements, scandium and gallium, a wide range of proteins can be analyzed, regardless of their salt content, buffer composition, additives and amino acid composition. This strategy also enables quantification of matrix effects. Two potential issues associated with drying have been considered in this study: (1) Formation of heterogeneous residues of varying thickness and/or density; and (2) separation of the internal standard and protein during drying (which has to be prevented to allow accurate quantification). These issues were investigated by microbeam X-ray fluorescence (μXRF) with special emphasis on (I) the influence of sample support and (II) the protein / buffer system used. In the first part, a model protein was studied on well established sample supports used in TXRF, PIXE and XRF (Mylar, siliconized quartz, Plexiglas and silicon). In the second part we imaged proteins of different molecular weight, oligomerization state, bound metals and solubility. A partial separation of protein and internal standard was only observed with untreated silicon, suggesting it may not be an adequate support material. Siliconized quartz proved to be the least prone to heterogeneous drying of the sample and yielded the most reliable results.

Elemental Levels Analyzed by PIXE in Florida Alligators

NASA Astrophysics Data System (ADS)

Kuharik, J. C.; Kravchenko, I. I.; Dunnam, F. E.; Van Rinsvelt, H. A.; Ross, J. P.

2003-08-01

Unusual and alarming mortality of alligators (Alligator mississippiensis) has been reported from Lake Griffin, Florida, where almost 400 dead alligators have been observed since 1997. In addition, the hatch rate for alligator eggs around Lake Griffin fell below 10% and remains low (30-45%) while the normal hatch rate is typically 80%. Standard diagnostic methods have been ineffective in determining the cause of the phenomenon. Many possibilities have been considered including pollutants, nutrition, and toxic algae. Particle Induced X-ray Emission (PIXE) analysis is highly suitable for investigating concentrations of a wide range of elements in animal tissue. Liver, kidney and spinal cord tissues from healthy and sick alligators have been analyzed by PIXE for elemental content. Initial results showed positive correlation between certain elements and neural impairment and morbidity of alligators in Lake Griffin, but have failed to prove significant.

PIXE study of Cuban quaternary paleoclimate geological samples and speleothems.

PubMed

Montero, M E; Aspiazu, J; Pajón, J; Miranda, S; Moreno, E

2000-02-01

PIXE elemental analysis of sediments, speleothems, and other geological formations related to the karst of the Sierra de San Carlos is presented. The similarity of the elemental composition of the sediments studied, as well as the alluvial regime which created them, indicate their common origin at each location. The Sr/Ca concentration ratio of a stalactite indicates that the average atmospheric temperature 12,000 and 18,000 years B.P. was colder than that of 6000 years B.P.

PREFACE: EMAS 2013 Workshop: 13th European Workshop on Modern Developments and Applications in Microbeam Analysis

NASA Astrophysics Data System (ADS)

Llovet, Xavier, Dr; Matthews, Mr Michael B.; Brisset, François, Dr; Guimarães, Fernanda, Dr; Vieira, Professor Joaquim M., Dr

2014-03-01

This volume of the IOP Conference Series: Materials Science and Engineering contains papers from the 13th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from the 12th to the 16th of May 2013 in the Centro de Congressos do Alfândega, Porto, Portugal. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a very specific format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field. This workshop was organized in collaboration with LNEG - Laboratório Nacional de Energia e Geologia and SPMICROS - Sociedade Portuguesa de Microscopia. The technical programme included the following topics: electron probe microanalysis, future technologies, electron backscatter diffraction (EBSD), particle analysis, and applications. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2014 Microscopy and Microanalysis meeting at Hartford, Connecticut. The prize went to Shirin Kaboli, of the Department of Metals and Materials Engineering of McGill University (Montréal, Canada), for her talk entitled ''Plastic deformation studies with electron channelling contrast imaging and electron backscattered diffraction''. The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 74 posters from 21 countries were on display at the meeting and that the participants came from as far away as Japan, Canada and the USA. A selection of participants with posters was invited to give a short oral presentation of their work in three dedicated sessions. The prize for the best poster was an invitation to participate in the 22nd Australian Conference on Microscopy and Microanalysis (ACMM 23) at Adelaide, South Australia. The prize was awarded to Pierre Burdet of the EM Group of the Department of Materials Science and Metallurgy of the University of Cambridge (UK), for the poster entitled: ''3D EDS microanalysis by FIB-SEM: advantages of a low take-off angle''. This proceedings volume contains the full texts of 8 of the invited plenary lectures and of 13 papers on related topics originating from the posters presented at the workshop. All the papers have been subjected to peer review by a least two referees. January 2014 Acknowledgements On behalf of the European Microbeam Analysis Society I would like to thank all the invited speakers, session chairs and members of the discussion panels for making the meeting such a great success. Special thanks go to Fernanda Guimarães and Luc Van't dack who directed the organisation of the workshop giving freely of their time and talents. As was the case for previous workshops, the EMAS board in corpore was responsible for the scientific programme. The Workshop also included a commercial exhibition where many leading instrument suppliers were represented. Several companies that exhibited provided financial support, either by sponsoring an event or by advertising. Below, in alphabetical order, is a list of exhibiting companies and sponsors of the workshop. - Ametek GmbH, Edax Business Unit- IZASA Group Werfen - Bruker Nano GmbH- Jeol (Europe) SAS - Cameca SA- Porto Gran Cruz - Câmara Municipal do Porto- Oxford Instruments NanoAnalysis Ltd. - European Institute for Transuranium Elements (Germany)- Probe Software, Inc. - FEI Company- Tescan, a.s. Michael B Matthews EMAS President

PREFACE: EMAS 2011: 12th European Workshop on Modern Developments in Microbeam Analysis

NASA Astrophysics Data System (ADS)

Brisset, François; Dugne, Olivier; Robaut, Florence; Lábár, János L.; Walker, Clive T.

2012-03-01

This volume of IOP Conference Series: Materials Science and Engineering contains papers from the 12th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis, which took place from the 15-19 May 2011 in the Angers Congress Centre, Angers, France. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on a career in microbeam analysis can meet and discuss with the established experts. The workshops have a very specific format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field. This workshop was organized in collaboration with GN-MEBA - Groupement National de Microscopie Electronique à Balayage et de microAnalysis, France. The technical programme included the following topics: the limits of EPMA, new techniques, developments and concepts in microanalysis, microanalysis in the SEM, and new and less common applications of micro- and nanoanalysis. As at previous workshops there was also a special oral session for young scientists. The best presentation by a young scientist was awarded with an invitation to attend the 2012 Microscopy and Microanalysis meeting at Phoenix, Arizona. The prize went to Pierre Burdet, of the Federal Institute of Technology of Lausanne (EPFL), for his talk entitled '3D EDS microanalysis by FIB-SEM: enhancement of elemental quantification'. The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 74 posters from 18 countries were on display at the meeting, and that the participants came from as far away as Japan, Canada and the USA. A selection of participants with posters were invited to give a short oral presentation of their work in three dedicated sessions. The prize for the best poster was an invitation to participate in the 22nd Australian Conference on Microscopy and Microanalysis (ACMM 22) at Perth, Western Australia. The prize was awarded to G Samardzija of the Jozef Stefan Institute, Ljubljana, for the poster entitled: 'EPMA-WDS quantitative compositional analysis of barium titanate ceramics doped with cerium'. This proceedings volume contains the full texts of 5 of the invited plenary lectures and of 23 papers on related topics originating from the posters presented at the workshop. All the papers have been subjected to peer review by a least two referees. January 2012 Acknowledgements On behalf of the European Microbeam Analysis Society I would like to thank all the invited speakers, session chairs and members of the discussion panels for making the meeting such a great success. Special thanks go to François Brisset and Luc Van't dack who directed the organisation of the workshop giving freely of their time and talents. As was the case for previous workshops, the EMAS board in corpore was responsible for the scientific programme. The technical exhibition, which occupied 130 sq.m of floor space, was outstanding. It was very encouraging to see new instruments on display, including a FEG electron microprobe as a first worldwide presentation. Moreover, almost all the companies that exhibited provided financial support, either by sponsoring an event or by advertising. Below, in alphabetical order, is a list of exhibiting companies and sponsors of the workshop: Ametek GmbH, Edax Business UnitGN-MEBA Bruker Nano GmbHJeol (Europe) SAS CamecaL'Oréal, Direction Générale Recherche et Innovation Carl Zeiss NTSNanoMEGAS sprl Commissariat à l'Energie AtomiqueOxford Instruments SAS European Institute for Transuranium Elements (Germany)Probe Software, Inc. ElexienceSAMx FEI CompanyTarget-Messtechnik Fondis Electronic SAThermo Fisher Scientific Gatan (France) Clive T. Walker EMAS President

PIXE analysis of trace metals in selenium and copper deficient mice exposed to influenza virus and salicylate

NASA Astrophysics Data System (ADS)

Andres, J. M.; Hurd, R. W.; Van Rinsvelt, H. A.; Small, P. A.; Maenhaut, W.; Vandenhaute, J.

1987-03-01

Reye's syndrome is an acute illness in children manifested by encephalopathy, fatty infiltration of liver, and thymic hypoplasia. The syndrome usually occurs in a susceptible individual with a viral illness who has ingested salicylate. We previously investigated the metal status of children with this syndrome; serum Se and Cu levels were noted to be decreased. Chronic aspirin treatment of rats also produced alterations of serum Se, and liver Se and Cu. We now report our observations for an experimental model of Reye's syndrome. Analysis by PIXE of various metals in Se- and Cu-deficient mice exposed to virus and salicylate are discussed.

IBA techniques: Examples of useful combinations for the characterisation of cultural heritage materials

NASA Astrophysics Data System (ADS)

Beck, L.; Pichon, L.; Moignard, B.; Guillou, T.; Walter, P.

2011-12-01

For many years, ion beam analysis techniques have successfully been used to the study of cultural heritage objects. The chemical composition of work art is usually determined by PIXE, but in many cases, RBS and/or PIGE can provide useful complementary information. RBS gives information about the depth distribution and concentration in light elements, such as carbon and oxygen. In the past years, the experimental facilities at the AGLAE (Accélérateur Grand Louvre d'Analyse Élémentaire) accelerator has been progressively developed in order to apply simultaneously PIXE, PIGE and RBS under optimal conditions using an external beam. This combination is now routinely used for point analyses or mappings. In this contribution, we present several examples of applications: manufacturing technology of lustre-decorated ceramics and silver plating, control of altered or restored surfaces, and quantification of organic phase in painting and bone. The final conclusion is that the association of PIXE with RBS is very attractive for the investigation of cultural heritage objects, in particular of materials containing both mineral and organic components or possessing a multilayered structure. The first results of the production of monochromatic X-rays for radiography purposes by PIXE are also presented.

Applications of particle microbeams in space radiation research.

PubMed

Durante, Marco

2009-03-01

Galactic cosmic radiation is acknowledged as one of the major barriers to human space exploration. In space, astronauts are exposed to charged particles from Z = 1 (H) up to Z = 28 (Ni), but the probability of a hit to a specific single cell in the human body is low. Particle microbeams can deliver single charged particles of different charge and energy to single cells from different tissues, and microbeam studies are therefore very useful for improving current risk estimates for long-term space travel. 2D in vitro cell cultures can be very useful for establishing basic molecular mechanisms, but they are not sufficient to extrapolate risk, given the substantial evidence proving tissue effects are key in determining the response to radiation insult. 3D tissue or animal systems represent a more promising target for space radiobiology using microbeams.

Fiber-optic detector for real time dosimetry of a micro-planar x-ray beam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belley, Matthew D.; Stanton, Ian N.; Langloss, Brian W.

2015-04-15

Purpose: Here, the authors describe a dosimetry measurement technique for microbeam radiation therapy using a nanoparticle-terminated fiber-optic dosimeter (nano-FOD). Methods: The nano-FOD was placed in the center of a 2 cm diameter mouse phantom to measure the deep tissue dose and lateral beam profile of a planar x-ray microbeam. Results: The continuous dose rate at the x-ray microbeam peak measured with the nano-FOD was 1.91 ± 0.06 cGy s{sup −1}, a value 2.7% higher than that determined via radiochromic film measurements (1.86 ± 0.15 cGy s{sup −1}). The nano-FOD-determined lateral beam full-width half max value of 420 μm exceeded thatmore » measured using radiochromic film (320 μm). Due to the 8° angle of the collimated microbeam and resulting volumetric effects within the scintillator, the profile measurements reported here are estimated to achieve a resolution of ∼0.1 mm; however, for a beam angle of 0°, the theoretical resolution would approach the thickness of the scintillator (∼0.01 mm). Conclusions: This work provides proof-of-concept data and demonstrates that the novel nano-FOD device can be used to perform real-time dosimetry in microbeam radiation therapy to measure the continuous dose rate at the x-ray microbeam peak as well as the lateral beam shape.« less

Combined PIXE and X-ray SEM studies on time-resolved deposits of welding shop aerosols

NASA Astrophysics Data System (ADS)

Barfoot, K. M.; Mitchell, I. V.; Verheyen, F.; Babeliowsky, T.

1981-03-01

Time-resolved deposits of welding shop air particulates have been obtained using a streak sampling system. PIXE analysis of these deposits, using 2 MeV protons, typically revealed the presence of a large number of elements, with many in the range Z = 11-30. Strong variations, up to three orders of magnitude, in the concentrations of several elements such as Al, Si and Fe as well as Zn, Na, K and Ca were found. The 2 h sampling resolution normally used was found to be insufficient to follow the short pollution episodes that regularly occur in a welding shop environment and so sampling with a 20 min resolution was used. The variation of elemental concentrations for different sampling times together with information on the physical nature of these air particulates, determined with a scanning electron microscope (SEM) and Si(Li) X-ray detector attachment, are presented. This type of information together with that obtained from the PIXE analysis is of importance in industrial hygiene studies. The need to make corrections for partial filter clogging, based on air-flow rate monitoring, is discussed.

Spatiotemporal dynamics of DNA repair proteins following laser microbeam induced DNA damage – When is a DSB not a DSB?☆

PubMed Central

Reynolds, Pamela; Botchway, Stanley W.; Parker, Anthony W.; O’Neill, Peter

2013-01-01

The formation of DNA lesions poses a constant threat to cellular stability. Repair of endogenously and exogenously produced lesions has therefore been extensively studied, although the spatiotemporal dynamics of the repair processes has yet to be fully understood. One of the most recent advances to study the kinetics of DNA repair has been the development of laser microbeams to induce and visualize recruitment and loss of repair proteins to base damage in live mammalian cells. However, a number of studies have produced contradictory results that are likely caused by the different laser systems used reflecting in part the wavelength dependence of the damage induced. Additionally, the repair kinetics of laser microbeam induced DNA lesions have generally lacked consideration of the structural and chemical complexity of the DNA damage sites, which are known to greatly influence their reparability. In this review, we highlight the key considerations when embarking on laser microbeam experiments and interpreting the real time data from laser microbeam irradiations. We compare the repair kinetics from live cell imaging with biochemical and direct quantitative cellular measurements for DNA repair. PMID:23688615

Coupling and tuning of modal frequencies in direct current biased microelectromechanical systems arrays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kambali, Prashant N.; Swain, Gyanadutta; Pandey, Ashok Kumar, E-mail: ashok@iith.ac.in

2015-08-10

Understanding the coupling of different modal frequencies and their tuning mechanisms has become essential to design multi-frequency MEMS devices. In this work, we fabricate a MEMS beam with fixed boundaries separated from two side electrodes and a bottom electrode. Subsequently, we perform experiments to obtain the frequency variation of in-plane and out-of-plane mechanical modes of the microbeam with respect to both DC bias and laser heating. We show that the frequencies of the two modes coincide at a certain DC bias, which in turn can also be varied due to temperature. Subsequently, we develop a theoretical model to predict themore » variation of the two modes and their coupling due to a variable gap between the microbeam and electrodes, initial tension, and fringing field coefficients. Finally, we discuss the influence of frequency tuning parameters in arrays of 3, 33, and 40 microbeams, respectively. It is also found that the frequency bandwidth of a microbeam array can be increased to as high as 25 kHz for a 40 microbeam array with a DC bias of 80 V.« less

The first interdisciplinary experiments at the IMP high energy microbeam

NASA Astrophysics Data System (ADS)

Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Guo, Na; Liu, Wenjing; Ye, Fei; Sheng, Lina; Li, Qiang; Li, Huiyun

2015-04-01

The high energy beam of tens to hundred MeV/u ions possesses mm-to-cm penetration depth in materials and can be easily extracted into air without significant energy loss and beam scattering. Combination of high energy ions and microbeam technology facilitates the microprobe application to many practical studies in large scale samples. The IMP heavy ion microbeam facility has recently been integrated with microscopic positioning and targeting irradiation system. This paper introduced the first interdisciplinary experiments performed at the IMP microbeam facility using the beam of 80.5 MeV/u carbon ions. Bystander effect induction via medium transferring was not found in the micro-irradiation study using HeLa cells. The mouse irradiation experiment demonstrated that carbon irradiation of 10 Gy dose to its tuberomammillary nucleus did not impair the sleep nerve system. The fault injection attack on RSA (Rivest-Shamir-Adleman) decryption proved that the commercial field-programmable gate array chip is vulnerable in single event effect to low linear-energy-transfer carbon irradiation, and the attack can cause the leakage of RSA private key. This work demonstrates the potential of high energy microbeam in its application to biology, biomedical, radiation hardness, and information security studies.

The use of a single multielement standard for trace analysis in biological materials by external beam PIXE

NASA Astrophysics Data System (ADS)

Biswas, S. K.; Khaliquzzaman, M.; Islam, M. M.; Khan, A. H.

1984-04-01

The validity of the use of a single multielement standard for mass calibration in thick-target external beam PIXE analysis of biological materials has been investigated. In this study, the NBS orchard leaf, SRM 1571, was used as the basic standard for trace element analysis in other biological materials. Using the present procedure, the concentrations of K, Ca, Mn, Fe, Ni, Cu, Zn, Br, Rb and Sr were determined in several NBS reference materials such as bovine liver, spinach, rice flour, etc., generally in 20 μC irradiations with 2.0 MeV protons. The analytical results are compared with certified values of the NBS as well as with other measurements and the sources of errors are discussed.

Characteristics of proton beams and secondary neutrons arising from two different beam nozzles

NASA Astrophysics Data System (ADS)

Choi, Yeon-Gyeong; Kim, Yu-Seok

2015-10-01

A tandem or a Van de Graaff accelerator with an energy of 3 MeV is typically used for Proton Induced X-ray Emission (PIXE) analysis. In this study, the beam line design used in the PIXE analysis, instead of the typical low-energy accelerator, was used to increase the production of isotopes from a 13-MeV cyclotron. For the PIXE analysis, the proton beam should be focused at the target through a nozzle after degrading the proton beams energy from 13 MeV to 3 MeV by using an energy degrader. Previous studies have been conducted to determine the most appropriate material for and the thickness of the energy degrader. From the energy distribution of the degraded proton beam and the neutron occurrence rate at the degrader, an aluminum nozzle of X thickness was determined to be the most appropriate nozzle construction. Neutrons are created by the collision of 3-MeV protons in the nozzle after passage through the energy degrader. In addition, a proton beam of sufficient intensity is required for a non-destructive PIXE analysis. Therefore, if nozzle design is to be optimized, the number of neutrons that arise from the collision of protons inside the nozzle, as well as the track direction of the generated secondary neutrons, must be considered, with the primary aim of ensuring that a sufficient number of protons pass through the nozzle as a direct beam. A number of laboratories are currently conducting research related to the design of nozzles used in accelerator fields, mostly medical fields. This paper presents a comparative analysis of two typical nozzle shapes in order to minimize the loss of protons and the generation of secondary neutrons. The neutron occurrence rate and the number of protons that pass through the nozzle were analyzed by using a Particle and Heavy Ion Transport code System (PHITS) program in order to identify the nozzle that generated the strongest proton beam.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, S; Zhang, J; Hadsell, M

Purpose: Microbeam radiation therapy and GRID therapy are different forms of Spatially-Fractioned Radiation Therapy (SFRT) that is fundamentally different from the conventional seamless and temporally fractionated radiation therapy. SFRT is characterized by a ultra-high dose (10s –100s Gy) dose single treatment with drastic inhomogeneity pattern of given spatial frequencies. Preclinical and limited clinical studies have shown that the SFRT treatments may offer significant improvements in reducing treatment toxicity, especially for those patients who have not benefited from the state-of-the-art radiation therapy approaches. This preliminary study aims to elucidate the underlying working mechanisms of SFRT, which currently remains poorly understood. Methods:more » A genetically engineered 4T1 murine mammary carcinoma cell line and nude mice skin fold window chamber were used. A nanotechnology-based 160kV x-ray irradiator delivered 50Gy (entrance dose) single treatments of microbeam or seamless radiation. Animals were in 3 groups: mock, seamless radiation, and 300μm microbeam radiation. The windows were imaged using a hyperspectral system to capture total hemoglobin/saturation, GFP fluorescence emission, RFP fluorescence emission, and vessel density at 9 time points up to 7 days post radiation. Results: We found unique physiologic changes in different tumor/normal tissue regions and differential effects between seamless and microbeam treatments. They include 1) compared to microbeam and mock radiation seamless radiation damaged more microvasculature in tumor-surrounding normal tissue, 2) a pronounced angiogenic effect was observed with vascular proliferation in the microbeam irradiated portion of the tumor days post treatment (no such effect observed in seamless and mock groups), and 3) a notable change in tumor vascular orientation was observed where vessels initially oriented parallel to the beam length were replaced by vessels running perpendicular to the irradiation portion of the tumor. Conclusion: Our preliminary study indicated that microbeam radiation modified tumor microenvironment in ways significantly different than of the conventional seamless radiation.« less

Trace elements in lake sediments measured by the PIXE technique

NASA Astrophysics Data System (ADS)

Gatti, Luciana V.; Mozeto, Antônio A.; Artaxo, Paulo

1999-04-01

Lakes are ecosystems where there is a great potential of metal accumulation in sediments due to their depositional characteristics. Total concentration of trace elements was measured on a 50 cm long sediment core from the Infernão Lake, that is an oxbow lake of the Moji-Guaçu River basin, in the state of São Paulo, Brazil. Dating of the core shows up to 180 yrs old sediment layers. The use of the PIXE technique for elemental analysis avoids the traditional acid digestion procedure common in other techniques. The multielemental characteristic of PIXE allows a simultaneous determination of about 20 elements in the sediment samples, such as, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr, Ba, and Pb. Average values for the elemental composition were found to be similar to the bulk crustal composition. The lake flooding pattern strongly influences the time series of the elemental profiles. Factor analysis of the elemental variability shows five factors. Two of the factors represent the mineralogical matrix, and others represent the organic component, a factor with lead, and another loaded with chromium. The mineralogical component consists of elements such as, Fe, Al, V, Ti, Mn, Ni, K, Zr, Sr, Cu and Zn. The variability of Si is explained by two distinct factors, because it is influenced by two different sources, aluminum-silicates and quartz, and the effect of inundation are different for each other. The organic matter is strongly associated with calcium, and also bounded with S, Zn, Cu and P. Lead and chromium appears as separated factors, although it is not clear the evidences for their anthropogenic origin. The techniques developed for sample preparation and PIXE analysis was proven as advantageous and provided very good reproducibility and accuracy.

Heavy Ion Microbeam and Broadbeam Transients in SiGe HBTs

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Dodd, Paul E.; Ferlet-Cavrois, Veronique; Baggio, Jacques; Paillet, Philippe; Duhamel, Olivier; Phillips, Stanley D.;

Design of a proton microbeam of the PEFP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Kye Ryung; Kim, Yong Hwan; Chang, Ji Ho

2008-02-15

The PEFP has been developing a 100 MeV proton linear accelerator and user facilities for 20 and 100 MeV proton beams. At one end of the five 20 MeV proton beam lines, a proton microbeam construction was considered for an application in the fields of material, biological, and medical sciences. To develop the proton microbeam, realization of a few MeV proton beam with a few tens of microamperes in diameter of a beam spot was essentially required. In this report, the basic descriptions of the proton microbeam which is composed of an energy degrader, slits, magnetic lens, a target chamber,more » and detectors are presented including a consideration of unfavorable aspects concerning some specific characteristics of a linear accelerator, such as pulse mode operation and fixed energy. Some calculation results from a Monte Carlo simulation by using the SRIM2006 and the TURTLE codes are also included.« less

Methods for implementing microbeam radiation therapy

DOEpatents

Dilmanian, F. Avraham; Morris, Gerard M.; Hainfeld, James F.

2007-03-20

A method of performing radiation therapy includes delivering a therapeutic dose such as X-ray only to a target (e.g., tumor) with continuous broad beam (or in-effect continuous) using arrays of parallel planes of radiation (microbeams/microplanar beams). Microbeams spare normal tissues, and when interlaced at a tumor, form a broad-beam for tumor ablation. Bidirectional interlaced microbeam radiation therapy (BIMRT) uses two orthogonal arrays with inter-beam spacing equal to beam thickness. Multidirectional interlaced MRT (MIMRT) includes irradiations of arrays from several angles, which interleave at the target. Contrast agents, such as tungsten and gold, are administered to preferentially increase the target dose relative to the dose in normal tissue. Lighter elements, such as iodine and gadolinium, are used as scattering agents in conjunction with non-interleaving geometries of array(s) (e.g., unidirectional or cross-fired (intersecting) to generate a broad beam effect only within the target by preferentially increasing the valley dose within the tumor.

Structural properties of rutile TiO2 nanoparticles accumulated in a model of gastrointestinal epithelium elucidated by micro-beam x-ray absorption fine structure spectroscopy

NASA Astrophysics Data System (ADS)

Veronesi, G.; Brun, E.; Fayard, B.; Cotte, M.; Carrière, M.

2012-05-01

Micro-beam x-ray absorption fine structure spectroscopy was used to investigate rutile TiO2 nanoparticles internalized into gastrointestinal cells during their crossing of a gut model barrier. Nanoparticles diluted in culture medium tend to accumulate in cells after 48 h exposure; however, no spectral differences arise between particles in cellular and in acellular environments, as corroborated by quantitative analysis. This finding establishes that no modification of the lattice properties of the nanoparticles occurs upon interaction with the barrier. These measurements demonstrate the possibility of interrogating nanoparticles in situ within cells, suggesting a way to investigate their fate when incorporated in biological hosts.

Distribution of lead in the brain tissues from DNTC patients using synchrotron radiation microbeams

NASA Astrophysics Data System (ADS)

Ide-Ektessabi, Ari; Ota, Yukihide; Ishihara, Ryoko; Mizuno, Yutaka; Takeuchi, Tohru

2005-12-01

Diffuse neurofibrillary tangles with calcification (DNTC) is a form of dementia with certain characteristics. Its pathology is characterized by cerebrum atrophy, calcification on globus pallidus and dentate nucleus and diffuse neurofibrillary tangles without senile plaques. In the present study brain tissues were prepared from patients with patients DNTC, calcified and non-calcified Alzheimer's disease (AD) patients. The brain tissues were examined non-destructively by X-ray fluorescence (XRF) spectroscopy using synchrotron radiation (SR) microbeams for trace metallic elements Ca, Fe, Cu, Zn and Pb. The XRF analysis showed that there were Pb concentrations in the calcified areas in the brain tissues with both DNTC and AD but there was none in those with non-calcified AD.

The preclinical set-up at the ID17 biomedical beamline to achieve high local dose deposition using interlaced microbeams

NASA Astrophysics Data System (ADS)

Bräuer-Krisch, E.; Nemoz, C.; Brochard, Th; Berruyer, G.; Renier, M.; Pouyatos, B.; Serduc, R.

2013-03-01

Microbeam Radiation Therapy (MRT) uses spatially a fractionated "white beam" (energies 50-350 keV) irradiation from a Synchrotron Source. The typical microbeams used at ID17 are 25-100μm-thick, spaced by 200-400μm, and carry extremely high dose rates (up to about 16 kGy/s). These microbeams are well tolerated by biological tissue, i.e. up to several hundred of Gy in the peaks. When valley doses, caused by Compton scattering in between two microbeams, remain within a dose regime similar to conventional RT, a superior tumour control can be achieved with MRT than with conventional RT. The normal tissue tolerance of these microscopically small beams is outstanding and well documented in the literature. The hypothesis of a differential effect in particular on the vasculature of normal versus tumoral tissue might best be proven by using large animal models with spontaneous tumors instead of small laboratory animals with transplantable tumors, an ongoing project on ID17. An alternative approach to deposit a high dose, while preserving the feature of the spatial separation of these microbeams outside the target has opened up new applications in preclinical research. The instrumentation of this method to produce such interlaced beams is presented with an outlook on the challenges to build a treatment platform for human patients. Dose measurements using Gafchromic films exposed in interlaced geometries with their steep profiles highlight the potential to deposit radiotoxic doses in the vicinity of radiosensitive tissues.

Naturally occurring levels of elements in fishes as determined by PIXE and XRF methods

NASA Astrophysics Data System (ADS)

Tallandini, L.; Giacobini, F.; Turchetto, M.; Galassini, S.; Liu, Q. X.; Shao, H. R.; Moschini, G.; Moro, R.; Gialanella, G.; Ghermandi, G.; Cecchi, R.; Injuk, J.; Valković, V.

1989-04-01

Naturally occurring levels of S, Cl, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se, Br, Sb, Sr and Pb were measured in the gills, liver and muscles of fishes ( Zosterisessor ophiocephalus Pall) in the northwestern region of the Adriatic Sea. The overall performance of PIXE and XRF methods was tested by the analysis of standard reference materials. The mean concentration values for elements were calculated from the distribution of experimentally determined concentration values. The obtained data are discussed in the framework of metal metabolism and toxicology.

PIXE analysis of pottery from the recovery of a renaissance wreck

NASA Astrophysics Data System (ADS)

Zucchiatti, A.; Cardoni, F.; Prati, P.; Lucarelli, F.; Mandò, P. A.; Martino, G. P.

1998-03-01

Pottery recovered in a recent marine archaeology campaign in the sea of Liguria (Italy), from the so-called leudo di Varazze wreck, has been analysed by PIXE. By measuring the ratio of each observed element to iron, we have characterised the composition of the clay with particular attention to possible contamination due to the long immersion in the sea. The present results have been associated, in a discriminant analysis, to those obtained during a previous campaign on a set of furnace rejects coming from the towns of Savona and Albissola, to investigate the provenance of the crockery. Both are located a few miles west of the wreck and were important pottery centres.

PREFACE: Proceedings of the 11th European Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis

NASA Astrophysics Data System (ADS)

2010-07-01

This volume of IOP Conference Series: Materials Science and Engineering contains papers from the 11th Workshop of the European Microbeam Analysis Society (EMAS) on Modern Developments and Applications in Microbeam Analysis which took place from 10-14 May 2009 in the Hotel Faltom, Gdynia, Poland. The primary aim of this series of workshops is to assess the state-of-the-art and reliability of microbeam analysis techniques. The workshops also provide a forum where students and young scientists starting out on careers in microbeam analysis can meet and discuss with the established experts. The workshops have a very distinct format comprising invited plenary lectures by internationally recognized experts, poster presentations by the participants and round table discussions on the key topics led by specialists in the field. For this workshop EMAS invited speakers on the following topics: EPMA, EBSD, fast energy-dispersive X-ray spectroscopy, three-dimensional microanalysis, and micro-and nanoanalysis in the natural resources industry. The continuing relevance of the EMAS workshops and the high regard in which they are held internationally can be seen from the fact that 69 posters from 16 countries were on display at the meeting and that the participants came from as far away as Japan and the USA. A number of participants with posters were invited to give short oral presentations of their work in two dedicated sessions. As at previous workshops there was also a special oral session for young scientists. Small cash prizes were awarded for the three best posters and for the best oral presentation by a young scientist. The prize for the best poster went to the contribution by G Tylko, S Dubchak, Z Banach and K Turnau, entitled Monte Carlo simulation for an assessment of standard validity and quantitative X-ray microanalysis in plant. Joanna Wojewoda-Budka of the Institute of Metallurgy and Materials Science, Krakow, received the prize for the best oral presentation by a young scientist for her talk entitled Application of focussed ion beam technique for TEM multilayer materials examination. This volume contains the full texts of 5 of the invited plenary lectures and of 24 papers on related topics originating from the posters presented at the workshop. All the papers have been subjected to peer review by a least two referees. January 2009 Acknowledgements On behalf of the European Microbeam Analysis Society I would like to thank all the invited speakers, session chairs and members of the discussion panels for making the meeting such a great success. Special thanks go to Michal Zelechower and Luc Van't dack who directed the organisation of the workshop giving freely of their time and talents. As was the case for previous workshops, the EMAS board in corpore was responsible for the scientific programme. I am particularly grateful to the exhibiting companies and sustaining members for their generous support of the workshop. In this context I would like particularly to mention: Silesian University of Technology, Gliwice Gdansk University of Technology Polish Society for Microscopy (PTMi), Krakow Polish Academy of Sciences - Materials Science Committee, Warsaw Polish Academy of Sciences - Institute of Metallurgy and Materials Science, Krakow Polish Academy of Sciences - Institute of Physics, Warsaw AGH University of Science and Technology, Krakow Warsaw University of Technology Below is a combined list of the exhibiting companies and sponsors of the workshop: Ametek GmbH (Germany) Blackwell Publishing Ltd (UK) Bruker AXS Microanalysis GmbH (Germany) Cameca SA (France) Carl Zeiss SMT GmbH (Germany) COMEF Aparatura Naukowo-Badawcza (Poland) EU-JRC: Inst. for Transuranium Elements (Germany) FEI Company (The Netherlands) IfG - Institute for Scientific Instruments GmbH (Germany) Jeol (Europe) SAS (France) John Wiley & Sons (UK) Olympus Soft Imaging Solutions GmbH (Germany) Oxford Instruments NanoAnalysis Ltd (UK) Probe Software, Inc. (USA) Roenalytic GmbH (Germany) Target-Messtechnik (Germany) Thermo Fisher Scientific BV (The Netherlands) Clive T Walker EMAS President János L Lábár Research Institute for Technical Physics and Materials Science, HAS, Konkoly-Thege M. u. 29-33, HU-1121 Budapest, Hungary Clive T Walker European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, DE-76125 Karlsruhe, Germany Michal Zelechower Silesian University of Technology, Department of Materials Science, ul. Krasinskiego 8, PL-40019 Katowice, Poland Pawel Zieba Polish Academy of Sciences, Institute of Metallurgy and Materials Science, ul. W. Reymonta 25, PL-30059 Krakow, Poland

GIT1/βPIX signaling proteins and PAK1 kinase regulate microtubule nucleation.

PubMed

Černohorská, Markéta; Sulimenko, Vadym; Hájková, Zuzana; Sulimenko, Tetyana; Sládková, Vladimíra; Vinopal, Stanislav; Dráberová, Eduarda; Dráber, Pavel

2016-06-01

Microtubule nucleation from γ-tubulin complexes, located at the centrosome, is an essential step in the formation of the microtubule cytoskeleton. However, the signaling mechanisms that regulate microtubule nucleation in interphase cells are largely unknown. In this study, we report that γ-tubulin is in complexes containing G protein-coupled receptor kinase-interacting protein 1 (GIT1), p21-activated kinase interacting exchange factor (βPIX), and p21 protein (Cdc42/Rac)-activated kinase 1 (PAK1) in various cell lines. Immunofluorescence microscopy revealed association of GIT1, βPIX and activated PAK1 with centrosomes. Microtubule regrowth experiments showed that depletion of βPIX stimulated microtubule nucleation, while depletion of GIT1 or PAK1 resulted in decreased nucleation in the interphase cells. These data were confirmed for GIT1 and βPIX by phenotypic rescue experiments, and counting of new microtubules emanating from centrosomes during the microtubule regrowth. The importance of PAK1 for microtubule nucleation was corroborated by the inhibition of its kinase activity with IPA-3 inhibitor. GIT1 with PAK1 thus represent positive regulators, and βPIX is a negative regulator of microtubule nucleation from the interphase centrosomes. The regulatory roles of GIT1, βPIX and PAK1 in microtubule nucleation correlated with recruitment of γ-tubulin to the centrosome. Furthermore, in vitro kinase assays showed that GIT1 and βPIX, but not γ-tubulin, serve as substrates for PAK1. Finally, direct interaction of γ-tubulin with the C-terminal domain of βPIX and the N-terminal domain of GIT1, which targets this protein to the centrosome, was determined by pull-down experiments. We propose that GIT1/βPIX signaling proteins with PAK1 kinase represent a novel regulatory mechanism of microtubule nucleation in interphase cells. Copyright © 2016 Elsevier B.V. All rights reserved.

MeV ion-beam analysis of optical data storage films

NASA Technical Reports Server (NTRS)

Leavitt, J. A.; Mcintyre, L. C., Jr.; Lin, Z.

1993-01-01

Our objectives are threefold: (1) to accurately characterize optical data storage films by MeV ion-beam analysis (IBA) for ODSC collaborators; (2) to develop new and/or improved analysis techniques; and (3) to expand the capabilities of the IBA facility itself. Using H-1(+), He-4(+), and N-15(++) ion beams in the 1.5 MeV to 10 MeV energy range from a 5.5 MV Van de Graaff accelerator, film thickness (in atoms/sq cm), stoichiometry, impurity concentration profiles, and crystalline structure were determined by Rutherford backscattering (RBS), high-energy backscattering, channeling, nuclear reaction analysis (NRA) and proton induced X-ray emission (PIXE). Most of these techniques are discussed in detail in the ODSC Annual Report (February 17, 1987), p. 74. The PIXE technique is briefly discussed in the ODSC Annual Report (March 15, 1991), p. 23.

Piroxicam/2-hydroxypropyl-beta-cyclodextrin inclusion complex prepared by a new fluid-bed coating technique.

PubMed

Zhang, Xingwang; Wu, Danni; Lai, Jie; Lu, Yi; Yin, Zongning; Wu, Wei

2009-02-01

This work was aimed at investigating the feasibility of fluid-bed coating as a new method to prepare cyclodextrin inclusion complex. The inclusion complex of the model drug piroxicam (PIX) and 2-hydroxypropyl-beta-cyclodextrin (HPCD) in aqueous ethanol solution was sprayed and deposited onto the surface of the pellet substrate upon removal of the solvent. The coating process was fluent with high coating efficiency. Scanning electron microscopy revealed a coarse pellet surface, and a loosely packed coating structure. Significantly enhanced dissolution, over 90% at 5 min, was observed at stoichiometric PIX/HPCD molar ratio (1/1) and at a ratio with excessive HPCD (1/2). Differential scanning calorimetry and powder X-ray diffractometry confirmed absence of crystallinity of PIX at PIX/HPCD molar ratio of 1/1 and 1/2. Fourier transform-infrared spectrometry and Raman spectrometry revealed interaction between PIX and HPCD adding evidence on inclusion of PIX moieties into HPCD cavities. Solid-state (13)C NMR spectrometry indicated possible inclusion of PIX through the pyridine ring. It is concluded that fluid-bed coating has potential to be used as a new technique to prepare cyclodextrin inclusion complex.

3D model of filler melting with micro-beam plasma arc based on additive manufacturing technology

NASA Astrophysics Data System (ADS)

Chen, Weilin; Yang, Tao; Yang, Ruixin

2017-07-01

Additive manufacturing technology is a systematic process based on discrete-accumulation principle, which is derived by the dimension of parts. Aiming at the dimension mathematical model and slicing problems in additive manufacturing process, the constitutive relations between micro-beam plasma welding parameters and the dimension of part were investigated. The slicing algorithm and slicing were also studied based on the dimension characteristics. By using the direct slicing algorithm according to the geometric characteristics of model, a hollow thin-wall spherical part was fabricated by 3D additive manufacturing technology using micro-beam plasma.

Laser microbeam irradiation and renucleation of mouse eggs. Final progress report, July 1, 1979-December 31, 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lin, T.P.

1983-01-01

We have combined laser microbeam irradiation of mouse egg nuclei with fusion to donor cell nuclei in order to develop a new procedure for transferring nuclei into mammalian eggs. We have been using virus-treated cells injected into the perivitelline for fusion with egg cells. Binucleate cells inside the zona pellucida were often produced indicating nuclear transfer between cells had occurred. To prevent the formation of such abortive polyploidy, host nuclei were inactivated with a laser microbeam. The subsequent cleavage of the microirradiated eggs has been studied.

Expanding the versatility of phage display II: improved affinity selection of folded domains on protein VII and IX of the filamentous phage.

PubMed

Løset, Geir Åge; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger

2011-02-24

Phage display is a leading technology for selection of binders with affinity for specific target molecules. Polypeptides are normally displayed as fusions to the major coat protein VIII (pVIII) or the minor coat protein III (pIII). Whereas pVIII display suffers from drawbacks such as heterogeneity in display levels and polypeptide fusion size limitations, toxicity and infection interference effects have been described for pIII display. Thus, display on other coat proteins such as pVII or pIX might be more attractive. Neither pVII nor pIX display have gained widespread use or been characterized in detail like pIII and pVIII display. Here we present a side-by-side comparison of display on pIII with display on pVII and pIX. Polypeptides of interest (POIs) are fused to pVII or pIX. The N-terminal periplasmic signal sequence, which is required for phage integration of pIII and pVIII and that has been added to pVII and pIX in earlier studies, is omitted altogether. Although the POI display level on pIII is higher than on pVII and pIX, affinity selection with pVII and pIX display libraries is shown to be particularly efficient. Display through pVII and/or pIX represent platforms with characteristics that differ from those of the pIII platform. We have explored this to increase the performance and expand the use of phage display. In the paper, we describe effective affinity selection of folded domains displayed on pVII or pIX. This makes both platforms more attractive alternatives to conventional pIII and pVIII display than they were before.

Geological and Inorganic Materials.

ERIC Educational Resources Information Center

Jackson, L. L.; And Others

1989-01-01

Presents a review focusing on techniques and their application to the analysis of geological and inorganic materials that offer significant changes to research and routine work. Covers geostandards, spectroscopy, plasmas, microbeam techniques, synchrotron X-ray methods, nuclear activation methods, chromatography, and electroanalytical methods.…

Weanling piglet cerebellum: a surrogate for tolerance to MRT (microbeam radiation therapy) in pediatric neuro-oncology

NASA Astrophysics Data System (ADS)

Laissue, Jean A.; Blattmann, Hans; Di Michiel, Marco; Slatkin, Daniel N.; Lyubimova, Nadia; Guzman, Raphael; Zimmermann, Werner; Birrer, Stephan; Bley, Tim; Kircher, Patrick; Stettler, Regina; Fatzer, Rosmarie; Jaggy, Andre; Smilowitz, Henry; Brauer, Elke; Bravin, Alberto; Le Duc, Geraldine; Nemoz, Christian; Renier, Michel; Thomlinson, William C.; Stepanek, Jiri; Wagner, Hans-Peter

2001-12-01

The cerebellum of the weanling piglet (Yorkshire) was used as a surrogate for the radiosensitive human infant cerebellum in a Swiss-led program of experimental microbeam radiation therapy (MRT) at the ESRF. Five weanlings in a 47 day old litter of seven, and eight weanlings in a 40 day old litter of eleven were irradiated in November, 1999 and June, 2000, respectively. A 1.5 cm-wide x 1.5 xm-high array of equally space approximately equals 20-30 micrometers wide, upright microbeams spaced at 210 micrometers intervals was propagated horizontally, left to right, through the cerebella of the prone, anesthetized piglets. Skin-entrance intra-microbeam peak adsorbed doses were uniform, either 150, 300, 425, or 600 gray (Gy). Peak and inter-microbeam (valley) absorbed doses in the cerebellum were computed with the PSI version of the Monte Carlo code GEANT and benchmarked using Gafchromic and radiochromic film microdosimetry. For approximately equals 66 weeks [first litter; until euthanasia], or approximately equals 57 weeks [second litter; until July 30, 2001] after irradiation, the littermates were developmentally, behaviorally, neurologically and radiologically normal as observed and tested by experienced farmers and veterinary scientists unaware of which piglets were irradiated or sham-irradiated. Morever, MRT implemented at the ESRF with a similar array of microbeams and a uniform skin-entrance peak dose of 625 Gy, followed by immunoprophylaxis, was shown to be palliative or curative in young adult rats bearing intracerebral gliosarcomas. These observations give further credence to MRT's potential as an adjunct therapy for brain tumors in infancy, when seamless therapeutic irradiation of the brain is hazardous.

External-RBS, PIXE and NRA analysis for ancient swords

NASA Astrophysics Data System (ADS)

Santos, Hellen C.; Added, Nemitala; Silva, Tiago F.; Rodrigues, C. L.

2015-02-01

Elemental composition of the steel of two ancient swords (Japanese and Damascus from a private collection) was characterized using in air IBA techniques. Our results contribute for the understanding the processes of manufacturing (hammering and quenching) and surface treatments applied in these swords. The Particle Induced X-ray Emission (PIXE) measurements along the Damascus blade allowed to identify and to trace a superficial concentration profile for the elements such Cr, Mn, Fe, Ni, Cu, Zn and As, while results for the Japanese blade showed only the presence of iron. The carbon content on the surface was also investigated using a resonant region in the Elastic Backscattering Spectrometry (EBS) measurements and the results have shown a slightly difference between the surfaces under investigation. In order to investigate the nitrogen content on surface, that could explain the hardening process, we used Nuclear Reaction Analysis (NRA) and the results shown that nitrogen content was under our detection limit for the technique (0.3% in mass). The measurements of PIXE, NRA and EBS were taken using the external beam setup installed at Lamfi - São Paulo/Brazil, the latter being successfully implemented for the first time in this facility.

PIGE-PIXE analysis of chewing sticks of pharmacological importance

NASA Astrophysics Data System (ADS)

Olabanji, S. O.; Makanju, O. V.; Haque, A. M. I.; Buoso, M. C.; Ceccato, D.; Cherubini, R.; Moschini, G.

1996-06-01

PIGE and PIXE techniques were employed for the determination of the major, minor and trace elemental concentrations in chewing sticks of pharmacological importance namely: Butyrospermum paradoxum, Garcinia kola, Distemonanthus benthamianus, Bridelia ferruginea, Anogeissus leiocarpus, Terminalia glaucescens and Fagara rubescens, respectively. The concentration of fluorine which is very important for human dental enamel was specially determined using the 19F(p, p'γ) 19F reaction. For decades these chewing sticks when used alone without toothpastes have proven to be very efficient, effective and reliable in cleaning the teeth of many people particularly in Nigeria and some other countries in Africa. The teeth of users are usually very strong, clean, fresh and devoid of germs and caries. Even with the advent of modern toothpastes with special additions of fluorine, the use of these popular and efficient chewing sticks is still unabated. Many people including the elite use them solely, a few others combine their use with modern toothpastes and brush. Proton beams produced by the 7 MV CN and 2.5 MV AN 2000 Van de Graaff accelerators at INFN, Laboratori Nazionali di Legnaro (LNL), Padova, Italy were used for the PIGE and PIXE analysis, respectively. Results of this novel study are presented and discussed.

Mars Mineralogy by Microbeam Raman Spectrometry

NASA Technical Reports Server (NTRS)

Haskin, Larry A.; Wang, Alian; Jolliff, Bradley L.; Wdowiak, Thomas J.; Agresti, David G.; Lane, Arthur L.; Squyres, Steven W.

2001-01-01

The Mars Microbeam Raman Spectrometer, under development at Washington University and the Jet Propulsion Laboratory, can identify oxide, sulfide, and oxyanion minerals, bound water and OH, and organic and graphitic carbon in Mars rocks and soils in situ. Additional information is contained in the original extended abstract.

Unidirectional x-ray microbeam radiosurgery of infantile neuraxial malignancies: estimations of tolerable valley doses

NASA Astrophysics Data System (ADS)

Hanson, A. L.; Slatkin, D. N.; Laissue, J. A.

2013-03-01

Hindbrains of sedated, prone, suckling rats were irradiated 11-13 days postpartum horizontally from the left with an array of upright wiggler-generated synchrotron X-ray microbeams spaced either 105 or 210 μm apart. The microbeams were in an array of 48 (for the 205 μm interval) or of 96 (for the 105 μm interval), with microbeam widths ranging from 19 to 39 μm, the array having an approximately 1-cm-square cross section. The microbeams imparted doses of either ≍50 or ≍150 Gy to the inner skin (computed here as the average dose 0.5-1.5 mm deep to the surface of our phantom) at their entrance to the head, where their median energy was ≍120 keV. The array traversed the postero-superior quadrant of the phantom, which represented the occiput of the head, so that about one in five photons in the array bypassed the head altogether. The resultant radiation doses to the head were simulated by computing the tracks of thirty billion X-ray photons incident on the multislit collimator along with all >=1 keV secondary electrons from interactions in water of the photons entering the left circular wall of the 1.00 cm-radius, 1.55 cm-wide (i.e., "15.5 mm-long") cylindrical head phantom. The computations were performed using the Los Alamos National Laboratory Monte Carlo radiation transport computer program MCNPX, yielding ionization energies imparted to approximately twenty-four thousand 1.00 mmdeep, 10 μm-wide, up to 3.33 mm-high voxels distributed throughout one quadrant of the phantom, each representing up to 33.3 μg water. Computed nadir doses between microbeams were defined as the average of the three lowest doses between horizontally adjacent peak doses. We notice that nadir interbeam doses under 5 Gy were associated with neurologically minor and/or inconsequential sequelae fifteen months after irradiation and thus postulate that unidirectional microbeam radiosurgery using hindbrain nadir doses under 5 Gy may safely ameliorate the symptoms of some presently intractable human infantile neuraxial malignancies.

Topographic PIXE analysis of platinum levels in kidney slices from CIS-platin treated patients

NASA Astrophysics Data System (ADS)

Dikhoff, T. G. M. H.; Van Der Heide, J. A.; McVie, J. G.

1985-05-01

Concentrations of platinum and several other trace elements have been measured exploiting a 50 × 50 μ proton beam for PIXE analysis. The thickness of a selective germanium absorber for the spectral resolution of platinum L β and selenium K α peaks optimized, taking into account the fluorescent X-rays excited in the absorber material. The measurements have been performed in the framework of a project on the assessment of the toxicity of cytostatic platinum compounds. The lateral distributions of platinum in human kidneys and in dog tissues were measured. The highest concentrations of platinum were seen in arterial walls, followed by glomeruli and tubules. Chronic kidney damage may be correlated to this pattern of retention.

Observation of radiation damage induced by single-ion hits at the heavy ion microbeam system

NASA Astrophysics Data System (ADS)

Kamiya, Tomihiro; Sakai, Takuro; Hirao, Toshio; Oikawa, Masakazu

2001-07-01

A single-ion hit system combined with the JAERI heavy ion microbeam system can be applied to observe individual phenomena induced by interactions between high-energy ions and a semiconductor device using a technique to measure the pulse height of transient current (TC) signals. The reduction of the TC pulse height for a Si PIN photodiode was measured under irradiation of 15 MeV Ni ions onto various micron-sized areas in the diode. The data containing damage effect by these irradiations were analyzed with least-square fitting using a Weibull distribution function. Changes of the scale and the shape parameters as functions of the width of irradiation areas brought us an assumption that a charge collection in a diode has a micron level lateral extent larger than a spatial resolution of the microbeam at 1 μm. Numerical simulations for these measurements were made with a simplified two-dimensional model based on this assumption using a Monte Carlo method. Calculated data reproducing the pulse-height reductions by single-ion irradiations were analyzed using the same function as that for the measurement. The result of this analysis, which shows the same tendency in change of parameters as that by measurements, seems to support our assumption.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, R.F.; Kravchenko, I.I.; Kuharik, J.C.

Widespread use of chromated copper arsenate (CCA) as a wood preservative has led to increasing public concern regarding possible toxic contamination of areas surrounding CCA-treated structures, e.g., decks, playground equipment, etc. Appreciable leaching of arsenic, chromium, and copper into soils adjacent to such structures has been demonstrated via standard techniques of analytical chemistry. The advantages of PIXE [rapid analysis, quick sample turnover, possible lower cost] suggest its application to this area of interest. PIXE studies in our laboratory of CCA-contaminated soil samples show good agreement with previous analyses of As, Cu, Cr, and other heavy-elemental content, with some variability inmore » diffusion rates.« less

Micro-PIXE characterisation of uranium occurrence in the coal zones and the mudstones of the Springbok Flats Basin, South Africa

NASA Astrophysics Data System (ADS)

Nxumalo, V.; Kramers, J.; Mongwaketsi, N.; Przybyłowicz, W. J.

2017-08-01

Uranium occurrence and characterisation in the coal samples of the upper coal zones of the Vryheid Formation and mudstones of the Volksrust Formation was investigated using micro-PIXE (Proton-Induced X-ray Emission) and proton backscattering spectrometry (BS) in conjunction with the nuclear microprobe. Two styles of uranium mineralisation in the Springbok Flats Basin were found: syngenetic mineralisation in which uranium occurs organically bound with coal matrix, with no discrete uranium minerals formed, and epigenetic mineralisation in which uranium occurs in veins that are filled with coffinite with botryoidal texture in the mudstones of the Volksrust Formation, overlying the coal zones. Micro-PIXE analysis made it possible to map out trace elements (including uranium) associated with the coals at low levels of detection, which other techniques such as SEM-EDS and ore microscopy failed. This information will help in better understanding of the best extraction methods to be employed to recover uranium from the coals of the Springbok Flats Basin.

Characterization of Byzantine pottery from Oltina (Constanţa County), Romania, using PIXE and Optical Microscopy

NASA Astrophysics Data System (ADS)

Bugoi, Roxana; Talmaţchi, Cristina; Haitǎ, Constantin; Ceccato, Daniele

2018-02-01

An assemblage of 58 ceramic shards discovered in archaeological excavations at Oltina, Romania, dated to the 10th-11th century CE, was subjected to archaeometric investigations in order to reveal the raw materials and manufacturing techniques employed by the potters from the Lower Danube zone during the Byzantine ruling. The initial grouping of the shards according to stylistic criteria was refined by the subsequent petrographic study. Optical Microscopy (OM) detailed the general mineralogy and the pottery fabric, i.e. the textural characteristics, porosity and microstructure, surface treatments and firing. The PIXE analyses of potteries performed at AN2000 accelerator of LNL, INFN, Italy led to the identification of the chemical composition of the ceramic shards. The Hierarchical Cluster Analysis of the PIXE data evidenced several categories of shards with distinct compositional signatures, the main division being the one separating the ceramic fragments made of kaolinitic clays from the rest of the Oltina potteries.

Computational modelling of the cerebral cortical microvasculature: effect of x-ray microbeams versus broad beam irradiation

NASA Astrophysics Data System (ADS)

Merrem, A.; Bartzsch, S.; Laissue, J.; Oelfke, U.

2017-05-01

Microbeam Radiation Therapy is an innovative pre-clinical strategy which uses arrays of parallel, tens of micrometres wide kilo-voltage photon beams to treat tumours. These x-ray beams are typically generated on a synchrotron source. It was shown that these beam geometries allow exceptional normal tissue sparing from radiation damage while still being effective in tumour ablation. A final biological explanation for this enhanced therapeutic ratio has still not been found, some experimental data support an important role of the vasculature. In this work, the effect of microbeams on a normal microvascular network of the cerebral cortex was assessed in computer simulations and compared to the effect of homogeneous, seamless exposures at equal energy absorption. The anatomy of a cerebral microvascular network and the inflicted radiation damage were simulated to closely mimic experimental data using a novel probabilistic model of radiation damage to blood vessels. It was found that the spatial dose fractionation by microbeam arrays significantly decreased the vascular damage. The higher the peak-to-valley dose ratio, the more pronounced the sparing effect. Simulations of the radiation damage as a function of morphological parameters of the vascular network demonstrated that the distribution of blood vessel radii is a key parameter determining both the overall radiation damage of the vasculature and the dose-dependent differential effect of microbeam irradiation.

Expanding the Versatility of Phage Display II: Improved Affinity Selection of Folded Domains on Protein VII and IX of the Filamentous Phage

PubMed Central

Løset, Geir Åge; Roos, Norbert; Bogen, Bjarne; Sandlie, Inger

2011-01-01

Background Phage display is a leading technology for selection of binders with affinity for specific target molecules. Polypeptides are normally displayed as fusions to the major coat protein VIII (pVIII) or the minor coat protein III (pIII). Whereas pVIII display suffers from drawbacks such as heterogeneity in display levels and polypeptide fusion size limitations, toxicity and infection interference effects have been described for pIII display. Thus, display on other coat proteins such as pVII or pIX might be more attractive. Neither pVII nor pIX display have gained widespread use or been characterized in detail like pIII and pVIII display. Methodology/Principal Findings Here we present a side-by-side comparison of display on pIII with display on pVII and pIX. Polypeptides of interest (POIs) are fused to pVII or pIX. The N-terminal periplasmic signal sequence, which is required for phage integration of pIII and pVIII and that has been added to pVII and pIX in earlier studies, is omitted altogether. Although the POI display level on pIII is higher than on pVII and pIX, affinity selection with pVII and pIX display libraries is shown to be particularly efficient. Conclusions/Significance Display through pVII and/or pIX represent platforms with characteristics that differ from those of the pIII platform. We have explored this to increase the performance and expand the use of phage display. In the paper, we describe effective affinity selection of folded domains displayed on pVII or pIX. This makes both platforms more attractive alternatives to conventional pIII and pVIII display than they were before. PMID:21390283

The GIT–PIX complexes regulate the chemotactic response of rat basophilic leukaemia cells

PubMed Central

Gavina, Manuela; Za, Lorena; Molteni, Raffaella; Pardi, Ruggero; Curtis, Ivan de

2009-01-01

Background information. Cell motility entails the reorganization of the cytoskeleton and membrane trafficking for effective protrusion. The GIT–PIX protein complexes are involved in the regulation of cell motility and adhesion and in the endocytic traffic of members of the family of G-protein-coupled receptors. We have investigated the function of the endogenous GIT complexes in the regulation of cell motility stimulated by fMLP (formyl-Met-Leu-Phe) peptide, in a rat basophilic leukaemia RBL-2H3 cell line stably expressing an HA (haemagglutinin)-tagged receptor for the fMLP peptide. Results. Our analysis shows that RBL cells stably transfected with the chemoattractant receptor expressed both GIT1–PIX and GIT2–PIX endogenous complexes. We have used silencing of the different members of the complex by small interfering RNAs to study the effects on a number of events linked to agonist-induced cell migration. We found that cell adhesion was not affected by depletion of any of the proteins of the GIT complex, whereas agonist-enhanced cell spreading was inhibited. Analysis of agonist-stimulated haptotactic cell migration indicated a specific positive effect of GIT1 depletion on trans-well migration. The internalization of the formyl-peptide receptor was also inhibited by depletion of GIT1 and GIT2. The effects of the GIT complexes on trafficking of the receptors was confirmed by an antibody-enhanced agonist-induced internalization assay, showing that depletion of PIX, GIT1 or GIT2 protein caused decreased perinuclear accumulation of internalized receptors. Conclusions. Our results show that endogenous GIT complexes are involved in the regulation of chemoattractant-induced cell motility and receptor trafficking, and support previous findings indicating an important function of the GIT complexes in the regulation of different G-protein-coupled receptors. Our results also indicate that endogenous GIT1 and GIT2 regulate distinct subsets of agonist-induced responses and suggest a possible functional link between the control of receptor trafficking and the regulation of cell motility by GIT proteins. PMID:19912111

Rac1 Recruitment to the Archipelago Structure of the Focal Adhesion through the Fluid Membrane as Revealed by Single-Molecule Analysis

PubMed Central

Shibata, Akihiro C E; Chen, Limin H; Nagai, Rie; Ishidate, Fumiyoshi; Chadda, Rahul; Miwa, Yoshihiro; Naruse, Keiji; Shirai, Yuki M; Fujiwara, Takahiro K; Kusumi, Akihiro

2013-01-01

The focal adhesion (FA) is an integrin-based structure built in/on the plasma membrane (PM), linking the extracellular matrix to the actin stress-fibers, working as cell migration scaffolds. Previously, we proposed the archipelago architecture of the FA, in which FA largely consists of fluid membrane, dotted with small islands accumulating FA proteins: membrane molecules enter the inter-island channels in the FA zone rather freely, and the integrins in the FA-protein islands rapidly exchanges with those in the bulk membrane. Here, we examined how Rac1, a small G-protein regulating FA formation, and its activators αPIX and βPIX, are recruited to the FA zones. PIX molecules are recruited from the cytoplasm to the FA zones directly. In contrast, majorities of Rac1 molecules first arrive from the cytoplasm on the general inner PM surface, and then enter the FA zones via lateral diffusion on the PM, which is possible due to rapid Rac1 diffusion even within the FA zones, slowed only by a factor of two to four compared with that outside. The constitutively-active Rac1 mutant exhibited temporary and all-time immobilizations in the FA zone, suggesting that upon PIX-induced Rac1 activation at the FA-protein islands, Rac1 tends to be immobilized at the FA-protein islands. © 2013 Wiley Periodicals, Inc PMID:23341328

Spatial investigation of some uranium minerals using nuclear microprobe

NASA Astrophysics Data System (ADS)

Valter, Anton A.; Knight, Kim B.; Eremenko, Gelij K.; Magilin, Dmitry V.; Ponomarov, Artem A.; Pisansky, Anatoly I.; Romanenko, Alexander V.; Ponomarev, Alexander G.

2018-01-01

In this work, several individual grains of uranium minerals—uraninite with high content of Ca, Ca-rich boltwoodite, growths of uranophane with β-uranophane, and weeksite—from different uranium deposits were studied by a scanning nuclear microprobe. Particle-induced X-ray emission technique provided by the microprobe (µ-PIXE) was carried out to obtain a concentration and 2D distribution of elements in these minerals. In addition, energy dispersive X-ray spectrometry (SEM-EDS) provided by a scanning electron microscope was used. The types of minerals were determined by X-ray diffraction methods. Results of this study improved the understanding of trace elemental composition of the uranium minerals depending on their origin. Obtained signatures could be linked then to the sample provenance. Such data are important for nuclear forensics to identify the ore types and even specific ore bodies, when only small samples may be available for analysis. In this study, the µ-PIXE technique was used for obtaining the 2D distribution of trace elements that are not commonly measured by SEM-EDS at the relevant concentrations. The detected levels and precisions of elements determination by µ-PIXE were also defined. Using µ-PIXE, several micro mineral inclusions such as phosphate with high level of V and Si were identified. The age of the uranium minerals was estimated due to a significant content of radiogenic Pb that provides an additional parameter for determination of the main attributive characteristics of the minerals. This work also showed that due to its high elemental sensitivity the nuclear microprobe can be a new analytical tool for creating a nuclear forensic database from the known uranium deposits and a subsequent analysis of the intercepted illicit materials.

Geomorphometric multi-scale analysis for the recognition of Moon surface features using multi-resolution DTMs

NASA Astrophysics Data System (ADS)

Li, Ke; Chen, Jianping; Sofia, Giulia; Tarolli, Paolo

2014-05-01

Moon surface features have great significance in understanding and reconstructing the lunar geological evolution. Linear structures like rilles and ridges are closely related to the internal forced tectonic movement. The craters widely distributed on the moon are also the key research targets for external forced geological evolution. The extremely rare availability of samples and the difficulty for field works make remote sensing the most important approach for planetary studies. New and advanced lunar probes launched by China, U.S., Japan and India provide nowadays a lot of high-quality data, especially in the form of high-resolution Digital Terrain Models (DTMs), bringing new opportunities and challenges for feature extraction on the moon. The aim of this study is to recognize and extract lunar features using geomorphometric analysis based on multi-scale parameters and multi-resolution DTMs. The considered digital datasets include CE1-LAM (Chang'E One, Laser AltiMeter) data with resolution of 500m/pix, LRO-WAC (Lunar Reconnaissance Orbiter, Wide Angle Camera) data with resolution of 100m/pix, LRO-LOLA (Lunar Reconnaissance Orbiter, Lunar Orbiter Laser Altimeter) data with resolution of 60m/pix, and LRO-NAC (Lunar Reconnaissance Orbiter, Narrow Angle Camera) data with resolution of 2-5m/pix. We considered surface derivatives to recognize the linear structures including Rilles and Ridges. Different window scales and thresholds for are considered for feature extraction. We also calculated the roughness index to identify the erosion/deposits area within craters. The results underline the suitability of the adopted methods for feature recognition on the moon surface. The roughness index is found to be a useful tool to distinguish new craters, with higher roughness, from the old craters, which present a smooth and less rough surface.

Spatial investigation of some uranium minerals using nuclear microprobe

NASA Astrophysics Data System (ADS)

Valter, Anton A.; Knight, Kim B.; Eremenko, Gelij K.; Magilin, Dmitry V.; Ponomarov, Artem A.; Pisansky, Anatoly I.; Romanenko, Alexander V.; Ponomarev, Alexander G.

2018-06-01

In this work, several individual grains of uranium minerals—uraninite with high content of Ca, Ca-rich boltwoodite, growths of uranophane with β-uranophane, and weeksite—from different uranium deposits were studied by a scanning nuclear microprobe. Particle-induced X-ray emission technique provided by the microprobe (µ-PIXE) was carried out to obtain a concentration and 2D distribution of elements in these minerals. In addition, energy dispersive X-ray spectrometry (SEM-EDS) provided by a scanning electron microscope was used. The types of minerals were determined by X-ray diffraction methods. Results of this study improved the understanding of trace elemental composition of the uranium minerals depending on their origin. Obtained signatures could be linked then to the sample provenance. Such data are important for nuclear forensics to identify the ore types and even specific ore bodies, when only small samples may be available for analysis. In this study, the µ-PIXE technique was used for obtaining the 2D distribution of trace elements that are not commonly measured by SEM-EDS at the relevant concentrations. The detected levels and precisions of elements determination by µ-PIXE were also defined. Using µ-PIXE, several micro mineral inclusions such as phosphate with high level of V and Si were identified. The age of the uranium minerals was estimated due to a significant content of radiogenic Pb that provides an additional parameter for determination of the main attributive characteristics of the minerals. This work also showed that due to its high elemental sensitivity the nuclear microprobe can be a new analytical tool for creating a nuclear forensic database from the known uranium deposits and a subsequent analysis of the intercepted illicit materials.

Proton Induced X-Ray Emission (PIXE) Analysis to Measure Trace Metals in Soil Along the East River in Queens, New York

NASA Astrophysics Data System (ADS)

Chalise, Sajju; Conlan, Skye; Porat, Zachary; Labrake, Scott; Vineyard, Michael

2017-09-01

The Union College Ion-Beam Analysis Lab's 1.1 MV tandem Pelletron accelerator is used to determine the presence of heavy trace metals in Queens, NY between Astoria Park and 3.5 miles south to Gantry State Park. A PIXE analysis was performed on 0.5 g pelletized soil samples with a 2.2 MeV proton beam. The results show the presence of elements ranging from Ti to Pb with the concentration of Pb in Astoria Park (2200 +/-200 ppm) approximately ten times that of the Gantry State Park. We hypothesize that the high lead concentration at Astoria Park is due to the nearby Hell Gate Bridge, painted in 1916 with lead based paint, then sandblasted and repainted in the '90s. If the lead is from the repair of the bridge, then we should see the concentration decrease as we go further from the bridge. To test this, soil samples were collected and analyzed from seven different locations north and south of the bridge. The concentrations of lead decreased drastically within a 500 m radius and were approximately constant at greater distances. More soil samples need to be collected within the 500 m radius from bridge to identify the potential source of Pb. We will describe the experimental procedure, the PIXE analysis of soil samples, and present preliminary results on the distribution of heavy trace metals.

New results of GridPix TPCs

NASA Astrophysics Data System (ADS)

van der Graaf, Harry

2009-07-01

The Gossip detector, being a GridPix TPC equipped with a thin layer of gas, is a promising alternative for Si tracking detectors. In addition, GridPix would be an interesting way to read out the gaseous phase volume of bi-phase Liquid Xe cryostats of v-less double beta decay and rare event (i.e. WIMP) search experiments.

Further results from PIXE analysis of inks in Galileo's notes on motion

NASA Astrophysics Data System (ADS)

Del Carmine, P.; Giuntini, L.; Hooper, W.; Lucarelli, F.; Mandò, P. A.

1996-06-01

We have recently analysed the inks in some of the folios of Vol. 72 of Manoscritti galileiani, kept at the Biblioteca Nazionale Centrale di Firenze, which contains a collection of loose handwritten sheets containing undated notes, data from experiments and propositions on the problems of motion from different periods of Galileo's life. This paper reports specific results obtained from the analysis of some of these propositions, which allowed to make a contribution to their chronological attribution and therefore to the solution of some historical controversies. Even in the case where the "absolute" chronological attributions could not be made on the basis of comparison with dated documents, the PIXE results provided useful information to deny or confirm the hypothesis that different propositions were written in the same or in different periods.

Microbeam radiosurgery: An industrial perspective.

PubMed

Wright, Michael D

2015-09-01

In spite of its long demonstrated potential, microbeam radiosurgery (MBRS) has yet to be developed into a clinical tool. This article examines the problems associated with MBRS, and potential solutions. It is shown that a path to a clinically useful device is emerging. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Large deformation of uniaxially loaded slender microbeams on the basis of modified couple stress theory: Analytical solution and Galerkin-based method

NASA Astrophysics Data System (ADS)

Kiani, Keivan

2017-09-01

Large deformation regime of micro-scale slender beam-like structures subjected to axially pointed loads is of high interest to nanotechnologists and applied mechanics community. Herein, size-dependent nonlinear governing equations are derived by employing modified couple stress theory. Under various boundary conditions, analytical relations between axially applied loads and deformations are presented. Additionally, a novel Galerkin-based assumed mode method (AMM) is established to solve the highly nonlinear equations. In some particular cases, the predicted results by the analytical approach are also checked with those of AMM and a reasonably good agreement is reported. Subsequently, the key role of the material length scale on the load-deformation of microbeams is discussed and the deficiencies of the classical elasticity theory in predicting such a crucial mechanical behavior are explained in some detail. The influences of slenderness ratio and thickness of the microbeam on the obtained results are also examined. The present work could be considered as a pivotal step in better realizing the postbuckling behavior of nano-/micro- electro-mechanical systems consist of microbeams.

Microbeam radiation therapy

NASA Astrophysics Data System (ADS)

Laissue, Jean A.; Lyubimova, Nadia; Wagner, Hans-Peter; Archer, David W.; Slatkin, Daniel N.; Di Michiel, Marco; Nemoz, Christian; Renier, Michel; Brauer, Elke; Spanne, Per O.; Gebbers, Jan-Olef; Dixon, Keith; Blattmann, Hans

1999-10-01

The central nervous system of vertebrates, even when immature, displays extraordinary resistance to damage by microscopically narrow, multiple, parallel, planar beams of x rays. Imminently lethal gliosarcomas in the brains of mature rats can be inhibited and ablated by such microbeams with little or no harm to mature brain tissues and neurological function. Potentially palliative, conventional wide-beam radiotherapy of malignant brain tumors in human infants under three years of age is so fraught with the danger of disrupting the functional maturation of immature brain tissues around the targeted tumor that it is implemented infrequently. Other kinds of therapy for such tumors are often inadequate. We suggest that microbeam radiation therapy (MRT) might help to alleviate the situation. Wiggler-generated synchrotron x-rays were first used for experimental microplanar beam (microbeam) radiation therapy (MRT) at Brookhaven National Laboratory's National Synchrotron Light Source in the early 1990s. We now describe the progress achieved in MRT research to date using immature and adult rats irradiated at the European Synchrotron Radiation Facility in Grenoble, France, and investigated thereafter at the Institute of Pathology of the University of Bern.

Assessment of rat optic nerve damage due to microbeam radiation therapy in the treatment of glioblastomas.

PubMed

Mohamed, A; Worobec, S; Schultke, E

2008-01-01

Glioblastomas are the most common and aggressive subtype of human primary brain tumors. Due to their uncontrolled cellular proliferation, intense invasion, and lack of apoptosis, they are extremely difficult to treat. Currently, different approaches such as surgery, chemotherapy and radiation therapy have been employed as possible treatments however thus far; these treatments are not curative. Currently, microbeam radiation therapy (MRT) is being trialed in animal models of malignant brain tumors (rats) to aid in treatment. Some of the protocols tested have been shown to significantly increase survival rates. However, due to the high x-ray doses uses in MRT, the surrounding tissue of the targeted Glioblastomas may be irreversibly damaged. In previous studies, lens damage and clouding of the cornea have been observed in microbeam exposed eyes. However, to date no studies have assessed optic nerve damage. Therefore, this study examines the potential rat optic nerve damage following exposure to microbeam radiation therapy in the treatment of Glioblastomas. Although there appears to be no significant damage to the optic nerve, slight inflammation was observed within the extra ocular muscle.

Feasibility of employing thick microbeams from superficial and orthovoltage kVp x-ray tubes for radiotherapy of superficial cancers

NASA Astrophysics Data System (ADS)

Kamali-Zonouzi, P.; Shutt, A.; Nisbet, A.; Bradley, D. A.

2017-11-01

Preclinical investigations of thick microbeams show these to be feasible for use in radiotherapeutic dose delivery. To create the beams we access a radiotherapy x-ray tube that is familiarly used within a conventional clinical environment, coupling this with beam-defining grids. Beam characterisation, both single and in the form of arrays, has been by use of both MCNP simulation and direct Gafchromic EBT film dosimetry. As a first step in defining optimal exit-beam profiles over a range of beam energies, simulation has been made of the x-ray tube and numbers of beam-defining parallel geometry grids, the latter being made to vary in thickness, slit separation and material composition. For a grid positioned after the treatment applicator, and of similar design to those used in the first part of the study, MCNP simulation and Gafchromic EBT film were then applied in examining the resultant radiation profiles. MCNP simulations and direct dosimetry both show useful thick microbeams to be produced from the x-ray tube, with peak-to-valley dose ratios (PVDRs) in the approximate range 8.8-13.9. Although the potential to create thick microbeams using radiotherapy x-ray tubes and a grid has been demonstrated, Microbeam Radiation Therapy (MRT) would still need to be approved outside of the preclinical setting, a viable treatment technique of clinical interest needing to benefit for instance from substantially improved x-ray tube dose rates.

Proton-Induced X-Ray Emission Analysis of Crematorium Emissions

NASA Astrophysics Data System (ADS)

Ali, Salina; Nadareski, Benjamin; Safiq, Alexandrea; Smith, Jeremy; Yoskowitz, Josh; Labrake, Scott; Vineyard, Michael

2013-10-01

There has been considerable concern in recent years about possible mercury emissions from crematoria. We have performed a particle-induced X-ray emission (PIXE) analysis of atmospheric aerosol samples collected on the roof of the crematorium at Vale Cemetery in Schenectady, NY, to address this concern. The samples were collected with a nine-stage cascade impactor that separates the particulate matter according to particle size. The aerosol samples were bombarded with 2.2-MeV protons from the Union College 1.1-MV Pelletron Accelerator. The emitted X-rays were detected with a silicon drift detector and the X-ray energy spectra were analyzed using GUPIX software to determine the elemental concentrations. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury. The lower limit of detection for mercury in this experiment was approximately 0.2 ng/m3. We will describe the experimental procedure, discuss the PIXE analysis, and present preliminary results.

Micro-PIXE analysis of trace element concentrations of natural rubies from different locations in Myanmar

NASA Astrophysics Data System (ADS)

Sanchez, J. L.; Osipowicz, T.; Tang, S. M.; Tay, T. S.; Win, T. T.

1997-07-01

The trace element concentrations found in geological samples can shed light on the formation process. In the case of gemstones, which might be of artificial or natural origin, there is also considerable interest in the development of methods that provide identification of the origin of a sample. For rubies, trace element concentrations present in natural samples were shown previously to be significant indicators of the region of origin [S.M. Tang et al., Appl. Spectr. 42 (1988) 44, and 43 (1989) 219]. Here we report the results of micro-PIXE analyses of trace element (Ti, V, Cr, Fe, Cu and Ga) concentrations of a large set ( n = 130) of natural rough rubies from nine locations in Myanmar (Burma). The resulting concentrations are subjected to statistical analysis. Six of the nine groups form clusters when the data base is evaluated using tree clustering and principal component analysis.

Six stirrup handled Moche ceramic vessels from pre-Colombian Peru: a technical study applying PIXE spectrometry

NASA Astrophysics Data System (ADS)

Swann, C. P.; Caspi, Sara; Carlson, Janice

1999-04-01

Much has been said recently concerning the Moche culture of Peru (100 B.C. to 700 A.D. ) which preceded the more widely known Inca society. Since there was no written language, what is known about the Moche people has been through the artifacts produced, their design and craftsmanship. This study concerns the PIXE analysis of the matrix and the red and white surface patterns of six stirrup handled earthenware vessels. The results suggest different techniques were applied for producing the coloring and surface designs and that a common source of clays was not used in the construction.

Micro-PIXE evaluation of radioactive cesium transfer in contaminated soil samples

NASA Astrophysics Data System (ADS)

Fujishiro, F.; Ishii, K.; Matsuyama, S.; Arai, H.; Ishizaki, A.; Osada, N.; Sugai, H.; Kusano, K.; Nozawa, Y.; Yamauchi, S.; Karahashi, M.; Oshikawa, S.; Kikuchi, K.; Koshio, S.; Watanabe, K.; Suzuki, Y.

2014-01-01

Micro-PIXE analysis has been performed on two soil samples with high cesium activity concentrations. These soil samples were contaminated by fallout from the accident at Fukushima Daiichi Nuclear Power Plant. One exhibits a radioactive cesium transfer of ˜0.01, and the other shows a radioactive cesium transfer of less than 0.001, even though both samples have high cesium activity concentrations exceeding 10,000 Bq/kg. X-ray spectra and elemental images of the soil samples revealed the presence of chlorine, which can react with cesium to produce an inorganic soluble compound, and phosphorus-containing cesium-capturable organic compounds.

Cell micro-irradiation with MeV protons counted by an ultra-thin diamond membrane

NASA Astrophysics Data System (ADS)

Barberet, Philippe; Pomorski, Michal; Muggiolu, Giovanna; Torfeh, Eva; Claverie, Gérard; Huss, Cédric; Saada, Samuel; Devès, Guillaume; Simon, Marina; Seznec, Hervé

2017-12-01

We report the development of thin single crystal diamond membranes suitable for dose control in targeted cell irradiation experiments with a proton microbeam. A specific design was achieved to deliver single protons with a hit detection efficiency approaching 100%. The membranes have thicknesses between 1.8 and 3 μm and are used as vacuum windows on the microbeam line. The impact of these transmission detectors on the microbeam spot size is estimated by Monte-Carlo simulations, indicating that a beam lateral resolution below 2 μm is achieved. This is confirmed by experiments showing the accumulation online of X-ray Repair Cross-Complementing protein 1 (XRCC1)-Green Fluorescent Protein (GFP) at DNA damaged sites in living cells.

Large Area Coverage of a TPC Endcap with GridPix Detectors

NASA Astrophysics Data System (ADS)

Kaminski, Jochen

2018-02-01

The Large Prototype TPC at DESY, Hamburg, was built by the LCTPC collaboration as a testbed for new readout technologies of Time Projection Chambers. Up to seven modules of about 400 cm2 each can be placed in the endcap. Three of these modules were equipped with a total of 160 GridPix detectors. This is a combination of a highly pixelated readout ASIC and a Micromegas built on top. GridPix detectors have a very high efficiency of detecting primary electrons, which leads to excellent spatial and energy resolutions. For the first time a large number of GridPix detectors has been operated and long segments of tracks have been recorded with excellent precision.

The PIX-2 experiment: An overview

NASA Astrophysics Data System (ADS)

Purvis, C. K.

1985-03-01

The second Plasma Interactions Experiment (PIX-2) was launched in January 1983 as a piggyback on the second stage of the Delta launch vehicle that carried IRAS into orbit. Placed in a 870 km circular polar orbit, it returned 18 hrs of data on the plasma current collection and arcing behavior of solar arrays biased to +/-1000 V in steps. The four 500 sq cm solar array segments were biased singly and in combinations. In addition to the array segments PIX-2 carried a Sun sensor, a Langmuir probe to measure electron currents, and a hot-wire filament electron emitter to control vehicle potential during positive array bias sequences. The PIX-2 experiment is reviewed from program and operational perspectives.

Application of SEU imaging for analysis of device architecture using a 25 MeV/u 86Kr ion microbeam at HIRFL

NASA Astrophysics Data System (ADS)

Liu, Tianqi; Yang, Zhenlei; Guo, Jinlong; Du, Guanghua; Tong, Teng; Wang, Xiaohui; Su, Hong; Liu, Wenjing; Liu, Jiande; Wang, Bin; Ye, Bing; Liu, Jie

2017-08-01

The heavy-ion imaging of single event upset (SEU) in a flash-based field programmable gate array (FPGA) device was carried out for the first time at Heavy Ion Research Facility in Lanzhou (HIRFL). The three shift register chains with separated input and output configurations in device under test (DUT) were used to identify the corresponding logical area rapidly once an upset occurred. The logic units in DUT were partly configured in order to distinguish the registers in SEU images. Based on the above settings, the partial architecture of shift register chains in DUT was imaged by employing the microbeam of 86Kr ion with energy of 25 MeV/u in air. The results showed that the physical distribution of registers in DUT had a high consistency with its logical arrangement by comparing SEU image with logic configuration in scanned area.

Influence of the environment and phototoxicity of the live cell imaging system at IMP microbeam facility

NASA Astrophysics Data System (ADS)

Liu, Wenjing; Du, Guanghua; Guo, Jinlong; Wu, Ruqun; Wei, Junzhe; Chen, Hao; Li, Yaning; Zhao, Jing; Li, Xiaoyue

2017-08-01

To investigate the spatiotemporal dynamics of DNA damage and repair after the ion irradiation, an online live cell imaging system has been established based on the microbeam facility at Institute of Modern Physics (IMP). The system could provide a sterile and physiological environment by making use of heating plate and live cell imaging solution. The phototoxicity was investigated through the evaluation of DNA repair protein XRCC1 foci formed in HT1080-RFP cells during the imaging exposure. The intensity of the foci induced by phototoxicity was much lower compared with that of the foci induced by heavy ion hits. The results showed that although spontaneous foci were formed due to RFP exposure during live cell imaging, they had little impact on the analysis of the recruitment kinetics of XRCC1 in the foci induced by the ion irradiation.

CdTe detector based PIXE mapping of geological samples

NASA Astrophysics Data System (ADS)

Chaves, P. C.; Taborda, A.; de Oliveira, D. P. S.; Reis, M. A.

2014-01-01

A sample collected from a borehole drilled approximately 10 km ESE of Bragança, Trás-os-Montes, was analysed by standard and high energy PIXE at both CTN (previous ITN) PIXE setups. The sample is a fine-grained metapyroxenite grading to coarse-grained in the base with disseminated sulphides and fine veinlets of pyrrhotite and pyrite. Matrix composition was obtained at the standard PIXE setup using a 1.25 MeV H+ beam at three different spots. Medium and high Z elemental concentrations were then determined using the DT2fit and DT2simul codes (Reis et al., 2008, 2013 [1,2]), on the spectra obtained in the High Resolution and High Energy (HRHE)-PIXE setup (Chaves et al., 2013 [3]) by irradiation of the sample with a 3.8 MeV proton beam provided by the CTN 3 MV Tandetron accelerator. In this paper we present results, discuss detection limits of the method and the added value of the use of the CdTe detector in this context.

Characterization of the ePix100 prototype: a front-end ASIC for second-generation LCLS integrating hybrid pixel detectors

NASA Astrophysics Data System (ADS)

Caragiulo, P.; Dragone, A.; Markovic, B.; Herbst, R.; Nishimura, K.; Reese, B.; Herrmann, S.; Hart, P.; Blaj, G.; Segal, J.; Tomada, A.; Hasi, J.; Carini, G.; Kenney, C.; Haller, G.

2014-09-01

ePix100 is the first variant of a novel class of integrating pixel ASICs architectures optimized for the processing of signals in second generation LINAC Coherent Light Source (LCLS) X-Ray cameras. ePix100 is optimized for ultra-low noise application requiring high spatial resolution. ePix ASICs are based on a common platform composed of a random access analog matrix of pixel with global shutter, fast parallel column readout, and dedicated sigma-delta analog to digital converters per column. The ePix100 variant has 50μmx50μm pixels arranged in a 352x384 matrix, a resolution of 50e- r.m.s. and a signal range of 35fC (100 photons at 8keV). In its final version it will be able to sustain a frame rate of 1kHz. A first prototype has been fabricated and characterized and the measurement results are reported here.

ePix: a class of architectures for second generation LCLS cameras

DOE PAGES

Dragone, A.; Caragiulo, P.; Markovic, B.; ...

2014-03-31

ePix is a novel class of ASIC architectures, based on a common platform, optimized to build modular scalable detectors for LCLS. The platform architecture is composed of a random access analog matrix of pixel with global shutter, fast parallel column readout, and dedicated sigma-delta analog-to-digital converters per column. It also implements a dedicated control interface and all the required support electronics to perform configuration, calibration and readout of the matrix. Based on this platform a class of front-end ASICs and several camera modules, meeting different requirements, can be developed by designing specific pixel architectures. This approach reduces development time andmore » expands the possibility of integration of detector modules with different size, shape or functionality in the same camera. The ePix platform is currently under development together with the first two integrating pixel architectures: ePix100 dedicated to ultra low noise applications and ePix10k for high dynamic range applications.« less

Background considerations in the analysis of PIXE spectra by Artificial Neural Systems.

NASA Astrophysics Data System (ADS)

Correa, R.; Morales, J. R.; Requena, I.; Miranda, J.; Barrera, V. A.

2016-05-01

In order to study the importance of background in PIXE spectra to determine elemental concentrations in atmospheric aerosols using artificial neural systems ANS, two independently trained ANS were constructed, one which considered as input the net number of counts in the peak, and another which included the background. In the training and validation phases thirty eight spectra of aerosols collected in Santiago, Chile, were used. In both cases the elemental concentration values were similar. This fact was due to the intrinsic characteristic of ANS operating with normalized values of the net and total number of counts under the peaks, something that was verified in the analysis of 172 spectra obtained from aerosols collected in Mexico city. Therefore, networks operating under the mode which include background can reduce time and cost when dealing with large number of samples.

Elemental X-ray Imaging Using the Maia Detector Array: The Benefits and Challenges of Large Solid-Angle

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, C.G.; De Geronimo, G.; Kirkham, R.

2009-11-13

The fundamental parameter method for quantitative SXRF and PIXE analysis and imaging using the dynamic analysis method is extended to model the changing X-ray yields and detector sensitivity with angle across large detector arrays. The method is implemented in the GeoPIXE software and applied to cope with the large solid-angle of the new Maia 384 detector array and its 96 detector prototype developed by CSIRO and BNL for SXRF imaging applications at the Australian and NSLS synchrotrons. Peak-to-background is controlled by mitigating charge-sharing between detectors through careful optimization of a patterned molybdenum absorber mask. A geological application demonstrates the capabilitymore » of the method to produce high definition elemental images up to {approx}100 M pixels in size.« less

Accelerator-based analytical technique in the evaluation of some Nigeria’s natural minerals: Fluorite, tourmaline and topaz

NASA Astrophysics Data System (ADS)

Olabanji, S. O.; Ige, O. A.; Mazzoli, C.; Ceccato, D.; Akintunde, J. A.; De Poli, M.; Moschini, G.

2005-10-01

For the first time, the complementary accelerator-based analytical technique of PIXE and electron microprobe analysis (EMPA) were employed for the characterization of some Nigeria's natural minerals namely fluorite, tourmaline and topaz. These minerals occur in different areas in Nigeria. The minerals are mainly used as gemstones and for other scientific and technological applications and therefore are very important. There is need to characterize them to know the quality of these gemstones and update the geochemical data on them geared towards useful applications. PIXE analysis was carried out using the 1.8 MeV collimated proton beam from the 2.5 MV AN 2000 Van de Graaff accelerator at INFN, LNL, Legnaro, Padova, Italy. The novel results which show many elements at different concentrations in these minerals are presented and discussed.

The Australian millipede Dicranogonus pix Jeekel, 1982 (Diplopoda, Polydesmida, Paradoxosomatidae): a species with and without paranota

PubMed Central

Mesibov, Robert

2014-01-01

Abstract Dicranogonus pix Jeekel, 1982 occurs in Victoria and Tasmania, Australia, including the islands in eastern Bass Strait between the two States. There is only slight gonopod variation across this range, but Dicranogonus pix populations with and without paranota are separated in Bass Strait by the ca 50 km-wide gap between the Kent and Furneaux Groups of islands. PMID:25493065

Role of phospholipase Cgamma1 in cell spreading requires association with a beta-Pix/GIT1-containing complex, leading to activation of Cdc42 and Rac1.

PubMed

Jones, Neil P; Katan, Matilda

2007-08-01

The significance of multiprotein signaling complexes in cell motility is becoming increasingly important. We have previously shown that phospholipase Cgamma1 (PLCgamma1) is critical for integrin-mediated cell spreading and motility (N. Jones et al., J. Cell Sci. 118:2695-2706, 2005). In the current study we show that, on a basement membrane-type matrix, PLCgamma1 associates with the adaptor protein GIT1 and the Rac1/Cdc42 guanine exchange factor beta-Pix; GIT1 and beta-Pix form tight complexes independently of PLCgamma1. The association of PLCgamma1 with the complex requires both GIT1 and beta-Pix and the specific array region (gammaSA) of PLCgamma1. Mutations of PLCgamma1 within the gammaSA region reveal that association with this complex is essential for the phosphorylation of PLCgamma1 and the progression to an elongated morphology after integrin engagement. Short interfering RNA (siRNA) depletion of either beta-Pix or GIT1 inhibited cell spreading in a fashion similar to that seen with siRNA against PLCgamma1. Furthermore, siRNA depletion of PLCgamma1, beta-Pix, or GIT1 inhibited Cdc42 and Rac1 activation, while constitutively active forms of Cdc42 or Rac1, but not RhoA, were able to rescue the elongation of these cells. Signaling of the PLCgamma1/GIT1/beta-Pix complex to Cdc42/Rac1 was found to involve the activation of calpains, calcium-dependent proteases. Therefore, we propose that the association of PLCgamma1 with complexes containing GIT1 and beta-Pix is essential for its role in integrin-mediated cell spreading and motility. As a component of this complex, PLCgamma1 is also involved in the activation of Cdc42 and Rac1.

Using ICP and micro-PIXE to investigate possible differences in the mineral composition of genetically modified versus wild-type sorghum grain

NASA Astrophysics Data System (ADS)

Ndimba, R.; Cloete, K.; Mehlo, L.; Kossmann, J.; Mtshali, C.; Pineda-Vargas, C.

2017-08-01

In the present study, possible differences in the mineral composition of transgenic versus non-transgenic sorghum grains were investigated using inductively coupled atomic emission spectroscopy (ICP-AES); and, in-tissue elemental mapping by micro Proton-Induced X-ray Emission (micro-PIXE) analysis. ICP AES was used to analyse the bulk mineral content of the wholegrain flour derived from each genotype; whilst micro-PIXE was used to interrogate localised differences in mineral composition specific to certain areas of the grain, such as the bran layer and the central endosperm tissue. According to the results obtained, no significant difference in the average Fe, Zn or Ca content was found to differentiate the transgenic from the wild-type grain using ICP-AES. However, using micro-PIXE, a significant reduction in zinc could be detected in the bran layer of the transgenic grains relative to wild-type. Although it is difficult to draw firm conclusions, as a result of the small sample size used in this study, micro-PIXE has nonetheless proven itself as a useful technique for highlighting the possibility that there may be reduced levels of zinc accumulation in the bran layer of the transgenic grains. Given that the genetic modification targets proteins that are highly concentrated in certain parts of the bran tissue, it seems plausible that the reduced levels of zinc may be an unintended consequence of the silencing of kafirin proteins. Although no immediate health or nutritional concerns emerge from this preliminary finding, it is noted that zinc plays an important biological role within this part of the grain as a structural stabiliser and antioxidant factor. Further study is therefore needed to assess more definitively the extent of the apparent localised reduction in zinc in the transgenic grains and how this may affect other important grain quality characteristics.

Identification of ancient textile fibres from Khirbet Qumran caves using synchrotron radiation microbeam diffraction

NASA Astrophysics Data System (ADS)

Müller, Martin; Murphy, Bridget; Burghammer, Manfred; Riekel, Christian; Roberts, Mark; Papiz, Miroslav; Clarke, David; Gunneweg, Jan; Pantos, Emmanuel

2004-10-01

Archaeological textiles fragments from the caves of Qumran in the Dead Sea region were investigated by means of X-ray microbeam diffraction on single fibres. This non-destructive technique made the identification of the used plant textile fibres possible. Apart from bast fibres (mainly flax), cotton was identified which was most unexpected in the archaeological context.

Novel neutron sources at the Radiological Research Accelerator Facility

PubMed Central

Xu, Yanping; Garty, Guy; Marino, Stephen A.; Massey, Thomas N.; Randers-Pehrson, Gerhard; Johnson, Gary W.; Brenner, David J.

2012-01-01

Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10–20 micron in diameter. This facility is based on a Proton Microbeam, impinging on a thin lithium target near the threshold of the 7Li(p,n)7Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components. PMID:22545061

A Thermoelastic Damping Model for the Cone Microcantilever Resonator with Circular Cross-section

NASA Astrophysics Data System (ADS)

Li, Pu; Zhou, Hongyue

2017-07-01

Microbeams with variable cross-section have been applied in Microelectromechanical Systems (MEMS) resonators. Quality factor (Q-factor) is an important factor evaluating the performance of MEMS resonators, and high Q-factor stands for the excellent performance. Thermoelastic damping (TED), which has been verified as a fundamental energy lost mechanism for microresonators, determines the upper limit of Q-factor. TED can be calculated by the Zener’s model and Lifshits and Roukes (LR) model. However, for microbeam resonators with variable cross-sections, these two models become invalid in some cases. In this work, we derived the TED model for cone microcantilever with circular cross-section that is a representative non-uniform microbeam. The comparison of results obtained by the present model and Finite Element Method (FEM) model proves that the present model is valid for predicting TED value for cone microcantilever with circular cross-section. The results suggest that the first-order natural frequencies and TED values of cone microcantilever are larger than those of uniform microbeam for large aspect ratios (l/r 0). In addition, the Debye peak value of a uniform microcantilever is equal to 0.5ΔE, while that of cone microcantilever is about 0.438ΔE.

Novel neutron sources at the Radiological Research Accelerator Facility.

PubMed

Xu, Yanping; Garty, Guy; Marino, Stephen A; Massey, Thomas N; Randers-Pehrson, Gerhard; Johnson, Gary W; Brenner, David J

2012-03-16

Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons.We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target.A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a Proton Microbeam, impinging on a thin lithium target near the threshold of the (7)Li(p,n)(7)Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.

Novel neutron sources at the Radiological Research Accelerator Facility

DOE PAGES

Xu, Yanping; Garty, G.; Marino, S. A.; ...

2012-03-16

Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will bemore » based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a proton microbeam, impinging on a thin lithium target near the threshold of the Li-7(p,n)Be-7 reaction. Lastly, this novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.« less

Novel neutron sources at the Radiological Research Accelerator Facility

NASA Astrophysics Data System (ADS)

Xu, Y.; Garty, G.; Marino, S. A.; Massey, T. N.; Randers-Pehrson, G.; Johnson, G. W.; Brenner, D. J.

2012-03-01

Since the 1960s, the Radiological Research Accelerator Facility (RARAF) has been providing researchers in biology, chemistry and physics with advanced irradiation techniques, using charged particles, photons and neutrons. We are currently developing a unique facility at RARAF, to simulate neutron spectra from an improvised nuclear device (IND), based on calculations of the neutron spectrum at 1.5 km from the epicenter of the Hiroshima atom bomb. This is significantly different from a standard fission spectrum, because the spectrum changes as the neutrons are transported through air, and is dominated by neutron energies between 0.05 and 8 MeV. This facility will be based on a mixed proton/deuteron beam impinging on a thick beryllium target. A second, novel facility under development is our new neutron microbeam. The neutron microbeam will, for the first time, provide a kinematically collimated neutron beam, 10-20 micron in diameter. This facility is based on a proton microbeam, impinging on a thin lithium target near the threshold of the 7Li(p,n)7Be reaction. This novel neutron microbeam will enable studies of neutron damage to small targets, such as single cells, individual organs within small animals or microelectronic components.

Towards the differentiation of non-treated and treated corundum minerals by ion-beam-induced luminescence and other complementary techniques.

PubMed

Calvo del Castillo, H; Deprez, N; Dupuis, T; Mathis, F; Deneckere, A; Vandenabeele, P; Calderón, T; Strivay, D

2009-06-01

Differentiation of treated and non-treated gemstones is a chief concern for major jewellery import companies. Low-quality corundum specimens coming from Asia appear to be often treated with heat, BeO or flux in order to enhance their properties as precious minerals. A set of corundum samples, rubies and sapphires from different origins, both treated and non-treated has been analysed at the Centre Européen d'Archéométrie, with ion-beam-induced luminescence (IBIL) and other complementary techniques such as Raman, proton-induced X-ray emission (PIXE), and proton-induced gamma-ray emission (PIGE). IBIL, also known as ionoluminescence, has been used before to detect impurities or defects inside synthetic materials and natural minerals; its use for the discrimination of gemstone simulants or synthetic analogues has been elsewhere discussed (Cavenago-Bignami Moneta, Gemología, Tomo I Piedras preciosas, perlas, corales, marfil. Ediciones Omega, Barcelona, 1991). PIXE has been frequently applied in the archaeometric field for material characterisation and provenance studies of minerals (Hughes, Ruby & sapphire. RWH Publishing, Fallbrook, 1997; Calvo del Castillo et al., Anal Bioanal Chem 387:869-878, 2007; Calligaro et al., NIM-B 189:320-327, 2002) and PIGE complements the elemental analysis by detecting light elements in these materials such as-and lighter than-sodium that cannot be identified with the PIXE technique (Sanchez et al., NIM-B 130:682-686, 1997; Emmett et al., Gems Gemology 39:84-135, 2003). The micro-Raman technique has also been used complementarily to ion beam analysis techniques for mineral characterisation (Novak et al., Appl Surf Sci 231-232:917-920, 2004). The aim of this study is to provide new means for systematic analysis of corundum gemstone-quality mineral, alternative to the traditional gemmologic methods; for this purpose, a Spanish jewellery import company supplied us with a number of natural corundum samples coming from different places (part of them treated as explained above). The PIXE elemental concentrations of the samples showed large quantities of calcium and lead in some cases that can be linked to treatment with fluxes or lead oxide. The plot of the chromium and iron concentration grouped the samples in various aggregates that corresponded to the different types of corundum analysed. Micro-Raman complemented the PIXE analysis corroborating the presence of lead oxides but the use of the PIGE technique was not successful for the detection of beryllium due to the low cross section of the nuclear reaction chosen for its identification. IBIL was capable of distinguishing between treated and non-treated samples of the same type based on the luminescent features of the materials.

Particle Size Characterization of Water-Elutriated Libby Amphibole 2000 and RTI International Amosite

USGS Publications Warehouse

Lowers, Heather; Bern, Amy M.

2009-01-01

This report presents data on particle characterization analyzed by scanning electron microscopy on Libby amphibole collected by the U.S. Geological Survey in 2000 (LA2000) and amosite material collected by RTI International (RTI amosite). The particle characterization data were generated to support a portion of the Libby Action Plan. Prior to analysis, the raw LA2000 and RTI amosite materials were subjected to a preparation step. Each sample was water-elutriated by U.S. Environmental Protection Agency (USEPA) Office of Research and Development, Research Triangle Park using the methods generally described in another published report and then delivered to the U.S. Geological Survey, Denver Microbeam Laboratory for analysis. Data presented here represent analyses performed by the U.S. Geological Survey, Denver Microbeam Laboratory and USEPA National Enforcement Investigations Center. This report consists of two Excel spreadsheet files developed by USEPA, Region 8 Superfund Technical Assistance Unit and describe the particle size characterization of the LA2000 and RTI amosite, respectively. Multiple tabs and data entry cells exist in each spreadsheet and are defined herein.

External-beam PIXE spectrometry for the study of Punic jewellery (SW Spain): The geographical provenance of the palladium-bearing gold

NASA Astrophysics Data System (ADS)

Ontalba Salamanca, M. Á.; Gómez-Tubío, B.; Ortega-Feliu, I.; Respaldiza, M. Á.; Luisa de la Bandera, M.; Ovejero Zappino, G.; Bouzas, A.; Gómez-Morón, A.

2006-08-01

This paper presents the study of a set of Punic gold items (400 B.C.), from the Museum of Cádiz (Spain). An external beam set-up has been employed for the absolutely non-destructive analysis of the objects. PIXE spectrometry has been performed in order to characterize the metallic alloys and the manufacturing techniques. Compositional differences have been found and soldering procedures have been identified. By comparison with the rings and other coetaneous jewellery, the presence of palladium in the bulk alloy of the earrings can be pointed out. The geographical provenance of the palladium-bearing gold is discussed based on geological and archaeological considerations.

Substrate evaluation for a microbeam endstation using unstained cell imaging

PubMed Central

Flaccavento, G.; Folkard, M.; Noble, J.A.; Prise, K.M.; Vojnovic, B.

2010-01-01

A cellular imaging system, optimized for unstained cells seeded onto a thin substrate, is under development. This system will be a component of the endstation for the microbeam cell-irradiation facility at the University of Surrey. Previous irradiation experiments at the Gray Cancer Institute (GCI) have used Mylar™ film to support the cells [Folkard, M., Prise, K., Schettino, G., Shao, C., Gilchrist, S., Vojnovic, B., 2005. New insights into the cellular response to radiation using microbeams. Nucl. Instrum. Methods B 231, 189–194]. Although suitable for fluorescence microscopy, the Mylar™ often creates excessive optical noise when used with non-fluorescent microscopy. A variety of substrates are being investigated to provide appropriate optical clarity, cell adhesion, and radiation attenuation. This paper reports on our investigations to date. PMID:18684631

Note: Proton microbeam formation with continuously variable kinetic energy using a compact system for three-dimensional proton beam writing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohkubo, T., E-mail: ohkubo.takeru@jaea.go.jp; Ishii, Y.

A compact focused gaseous ion beam system has been developed to form proton microbeams of a few hundreds of keV with a penetration depth of micrometer range in 3-dimensional proton beam writing. Proton microbeams with kinetic energies of 100-140 keV were experimentally formed on the same point at a constant ratio of the kinetic energy of the object side to that of the image side. The experimental results indicate that the beam diameters were measured to be almost constant at approximately 6 μm at the same point with the kinetic energy range. These characteristics of the system were experimentally andmore » numerically demonstrated to be maintained as long as the ratio was constant.« less

Potential High Resolution Dosimeters For MRT

NASA Astrophysics Data System (ADS)

Bräuer-Krisch, E.; Rosenfeld, A.; Lerch, M.; Petasecca, M.; Akselrod, M.; Sykora, J.; Bartz, J.; Ptaszkiewicz, M.; Olko, P.; Berg, A.; Wieland, M.; Doran, S.; Brochard, T.; Kamlowski, A.; Cellere, G.; Paccagnella, A.; Siegbahn, E. A.; Prezado, Y.; Martinez-Rovira, I.; Bravin, A.; Dusseau, L.; Berkvens, P.

2010-07-01

Microbeam Radiation Therapy (MRT) uses highly collimated, quasi-parallel arrays of X-ray microbeams of 50-600 keV, produced by 2nd and 3rd generation synchrotron sources, such as the National Synchrotron Light Source (NSLS) in the U.S., and the European Synchrotron Radiation Facility (ESRF) in France, respectively. High dose rates are necessary to deliver therapeutic doses in microscopic volumes, to avoid spreading of the microbeams by cardiosynchronous movement of the tissues. A small beam divergence and a filtered white beam spectrum in the energy range between 30 and 250 keV results in the advantage of steep dose gradients with a sharper penumbra than that produced in conventional radiotherapy. MRT research over the past 20 years has allowed a vast number of results from preclinical trials on different animal models, including mice, rats, piglets and rabbits. Microbeams in the range between 10 and 100 micron width show an unprecedented sparing of normal radiosensitive tissues as well as preferential damage to malignant tumor tissues. Typically, MRT uses arrays of narrow (˜25-100 micron-wide) microplanar beams separated by wider (100-400 microns centre-to-centre, c-t-c) microplanar spaces. We note that thicker microbeams of 0.1-0.68 mm used by investigators at the NSLS are still called microbeams, although some invesigators in the community prefer to call them minibeams. This report, however, limits it discussion to 25-100 μm microbeams. Peak entrance doses of several hundreds of Gy are surprisingly well tolerated by normal tissues. High resolution dosimetry has been developed over the last two decades, but typical dose ranges are adapted to dose delivery in conventional Radiation Therapy (RT). Spatial resolution in the sub-millimetric range has been achieved, which is currently required for quality assurance measurements in Gamma-knife RT. Most typical commercially available detectors are not suitable for MRT applications at a dose rate of 16000 Gy/s, micron resolution and a dose range over several orders of magnitude. This paper will give an overview of all dosimeters tested in the past at the ESRF with their advantages and drawbacks. These detectors comprise: Ionization chambers, Alanine Dosimeters, MOSFET detectors, Gafchromic® films, Radiochromic polymers, TLDs, Polymer gels, Fluorescent Nuclear Track Detectors (Al2O3:C, Mg single crystal detectors), OSL detectors and Floating Gate-based dosimetry system. The aim of such a comparison shall help with a decision on which of these approaches is most suitable for high resolution dose measurements in MRT. The principle of these detectors will be presented including a comparison for some dosimeters exposed with the same irradiation geometry, namely a 1×1 cm5 field size with microbeam exposures at the surface, 0.1 cm and 1 cm in depth of a PMMA phantom. For these test exposures, the most relevant irradiation parameters for future clinical trials have been chosen: 50 micron FWHM and 400 micron c-t-c distance. The experimental data are compared with Monte Carlo calculations.

New Paranal Views

NASA Astrophysics Data System (ADS)

2001-01-01

Last year saw very good progress at ESO's Paranal Observatory , the site of the Very Large Telescope (VLT). The third and fourth 8.2-m Unit Telescopes, MELIPAL and YEPUN had "First Light" (cf. PR 01/00 and PR 18/00 ), while the first two, ANTU and KUEYEN , were busy collecting first-class data for hundreds of astronomers. Meanwhile, work continued towards the next phase of the VLT project, the combination of the telescopes into the VLT Interferometer. The test instrument, VINCI (cf. PR 22/00 ) is now being installed in the VLTI Laboratory at the centre of the observing platform on the top of Paranal. Below is a new collection of video sequences and photos that illustrate the latest developments at the Paranal Observatory. The were obtained by the EPR Video Team in December 2000. The photos are available in different formats, including "high-resolution" that is suitable for reproduction purposes. A related ESO Video News Reel for professional broadcasters will soon become available and will be announced via the usual channels. Overview Paranal Observatory (Dec. 2000) Video Clip 02a/01 [MPEG - 4.5Mb] ESO PR Video Clip 02a/01 "Paranal Observatory (December 2000)" (4875 frames/3:15 min) [MPEG Video+Audio; 160x120 pix; 4.5Mb] [MPEG Video+Audio; 320x240 pix; 13.5 Mb] [RealMedia; streaming; 34kps] [RealMedia; streaming; 200kps] ESO Video Clip 02a/01 shows some of the construction activities at the Paranal Observatory in December 2000, beginning with a general view of the site. Then follow views of the Residencia , a building that has been designed by Architects Auer and Weber in Munich - it integrates very well into the desert, creating a welcome recreational site for staff and visitors in this harsh environment. The next scenes focus on the "stations" for the auxiliary telescopes for the VLTI and the installation of two delay lines in the 140-m long underground tunnel. The following part of the video clip shows the start-up of the excavation work for the 2.6-m VLT Survey Telescope (VST) as well as the location known as the "NTT Peak", now under consideration for the installation of the 4-m VISTA telescope. The last images are from to the second 8.2-m Unit Telescope, KUEYEN, that has been in full use by the astronomers with the UVES and FORS2 instruments since April 2000. ESO PR Photo 04a/01 ESO PR Photo 04a/01 [Preview - JPEG: 466 x 400 pix - 58k] [Normal - JPEG: 931 x 800 pix - 688k] [Hires - JPEG: 3000 x 2577 pix - 7.6M] Caption : PR Photo 04a/01 shows an afternoon view from the Paranal summit towards East, with the Base Camp and the new Residencia on the slope to the right, above the valley in the shadow of the mountain. ESO PR Photo 04b/01 ESO PR Photo 04b/01 [Preview - JPEG: 791 x 400 pix - 89k] [Normal - JPEG: 1582 x 800 pix - 1.1Mk] [Hires - JPEG: 3000 x 1517 pix - 3.6M] PR Photo 04b/01 shows the ramp leading to the main entrance to the partly subterranean Residencia , with the steel skeleton for the dome over the central area in place. ESO PR Photo 04c/01 ESO PR Photo 04c/01 [Preview - JPEG: 498 x 400 pix - 65k] [Normal - JPEG: 995 x 800 pix - 640k] [Hires - JPEG: 3000 x 2411 pix - 6.6M] PR Photo 04c/01 is an indoor view of the reception hall under the dome, looking towards the main entrance. ESO PR Photo 04d/01 ESO PR Photo 04d/01 [Preview - JPEG: 472 x 400 pix - 61k] [Normal - JPEG: 944 x 800 pix - 632k] [Hires - JPEG: 3000 x 2543 pix - 5.8M] PR Photo 04d/01 shows the ramps from the reception area towards the rooms. The VLT Interferometer The Delay Lines consitute a most important element of the VLT Interferometer , cf. PR Photos 26a-e/00. At this moment, two Delay Lines are operational on site. A third system will be integrated early this year. The VLTI Delay Line is located in an underground tunnel that is 168 metres long and 8 metres wide. This configuration has been designed to accommodate up to eight Delay Lines, including their transfer optics in an ideal environment: stable temperature, high degree of cleanliness, low levels of straylight, low air turbulence. The positions of the Delay Line carriages are computed to adjust the Optical Path Lengths requested for the fringe pattern observation. The positions are controlled in real time by a laser metrology system, specially developed for this purpose. The position precision is about 20 nm (1 nm = 10 -9 m, or 1 millionth of a millimetre) over a distance of 120 metres. The maximum velocity is 0.50 m/s in position mode and maximum 0.05 m/s in operation. The system is designed for 25 year of operation and to survive earthquake up to 8.6 magnitude on the Richter scale. The VLTI Delay Line is a three-year project, carried out by ESO in collaboration with Dutch Space Holdings (formerly Fokker Space) and TPD-TNO . VLTI Delay Lines (December 2000) - ESO PR Video Clip 02b/01 [MPEG - 3.6Mb] ESO PR Video Clip 02b/01 "VLTI Delay Lines (December 2000)" (2000 frames/1:20 min) [MPEG Video+Audio; 160x120 pix; 3.6Mb] [MPEG Video+Audio; 320x240 pix; 13.7 Mb] [RealMedia; streaming; 34kps] [RealMedia; streaming; 200kps] ESO Video Clip 02b/00 shows the Delay Lines of the VLT Interferometer facility at Paranal during tests. One of the carriages is moving on 66-metre long rectified rails, driven by a linear motor. The carriage is equipped with three wheels in order to preserve high guidance accuracy. Another important element is the Cat's Eye that reflects the light from the telescope to the VLT instrumentation. This optical system is made of aluminium (including the mirrors) to avoid thermo-mechanical problems. ESO PR Photo 04e/01 ESO PR Photo 04e/01 [Preview - JPEG: 400 x 402 pix - 62k] [Normal - JPEG: 800 x 804 pix - 544k] [Hires - JPEG: 3000 x 3016 pix - 6.2M] Caption : PR Photo 04e/01 shows one of the 30 "stations" for the movable 1.8-m Auxiliary Telescopes. When one of these telescopes is positioned ("parked") on top of it, The light will be guided through the hole towards the Interferometric Tunnel and the Delay Lines. ESO PR Photo 04f/01 ESO PR Photo 04f/01 [Preview - JPEG: 568 x 400 pix - 96k] [Normal - JPEG: 1136 x 800 pix - 840k] [Hires - JPEG: 3000 x 2112 pix - 4.6M] PR Photo 04f/01 shows a general view of the Interferometric Tunnel and the Delay Lines. ESO PR Photo 04g/01 ESO PR Photo 04g/01 [Preview - JPEG: 406 x 400 pix - 62k] [Normal - JPEG: 812 x 800 pix - 448k] [Hires - JPEG: 3000 x 2956 pix - 5.5M] PR Photo 04g/01 shows one of the Delay Line carriages in parking position. The "NTT Peak" The "NTT Peak" is a mountain top located about 2 km to the north of Paranal. It received this name when ESO considered to move the 3.58-m New Technology Telescope from La Silla to this peak. The possibility of installing the 4-m VISTA telescope (cf. PR 03/00 ) on this peak is now being discussed. ESO PR Photo 04h/01 ESO PR Photo 04h/01 [Preview - JPEG: 630 x 400 pix - 89k] [Normal - JPEG: 1259 x 800 pix - 1.1M] [Hires - JPEG: 3000 x 1907 pix - 5.2M] PR Photo 04h/01 shows the view from the "NTT Peak" towards south, vith the Paranal mountain and the VLT enclosures in the background. ESO PR Photo 04i/01 ESO PR Photo 04i/01 [Preview - JPEG: 516 x 400 pix - 50k] [Normal - JPEG: 1031 x 800 pix - 664k] [Hires - JPEG: 3000 x 2328 pix - 6.0M] PR Photo 04i/01 is a view towards the "NTT Peak" from the top of the Paranal mountain. The access road and the concrete pillar that was used to support a site testing telescope at the top of this peak are seen This is the caption to ESO PR Photos 04a-1/01 and PR Video Clips 02a-b/01 . They may be reproduced, if credit is given to the European Southern Observatory. The ESO PR Video Clips service to visitors to the ESO website provides "animated" illustrations of the ongoing work and events at the European Southern Observatory. The most recent clip was: ESO PR Video Clip 01/01 about the Physics On Stage Festival (11 January 2001) . Information is also available on the web about other ESO videos.

Studying the spatial variability of Cr in agricultural field using both particle induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA) technique

NASA Astrophysics Data System (ADS)

Cruvinel, Paulo E.; Crestana, Sílvio; Artaxo, Paulo; Martins, JoséV.; Armelin, Maria JoséA.

1996-04-01

In the field of soil physics, a technique which permits a non-destructive, accurate and fast elemental analysis with a minimum of sample preparation effort is often desired. Although trace elements are minor components of the solid phase, they play an important role in soil fertility. Cr is of nutritional importance because it is a required element in human and animal nutrition. The immobility of Cr may be responsible for an inadequate Cr supply to plants. This work not only demonstrates the suitability of PIXE as a fast and non-destructive technique, useful to measure Cr content in soil samples, but also outlines a study of spatial variability of that element in agricultural field. To demonstrate the capability of the method soil samples were collected in a 5000 m 2 agricultural field. The soil samples were analyzed using both PIXE and INAA techniques. Besides, a Fourier interpolation technique was used to verify the distribution of Cr along of the sampled field. INAA was carried out by means of the γ-ray emitted by 51Cr(320 keV). Results show that there is a good linear relationship between the elemental concentration of Cr obtained using those techniques, i.e. a correlation coefficient of r2 = 0.82 was achieved.

PIXE analysis of medieval silver coins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelouahed, H. Ben, E-mail: habdelou@cern.ch; Gharbi, F.; Roumie, M.

2010-01-15

We applied the proton-induced X-ray emission (PIXE) analytical technique to twenty-eight medieval silver coins, selected from the Tunisian treasury. The purpose is to study the fineness evolution from the beginning of the 7th to the 15th centuries AD. Each silver coin was cleaned with a diluted acid solution and then exposed to a 3 MeV proton beam from a 1.7 MV tandem accelerator. To allow the simultaneous detection of light and heavy elements, a funny aluminum filter was positioned in front of the Si(Li) detector entrance which is placed at 135{sup o} to the beam direction. The elements Cu, Pb,more » and Au were observed in the studied coins along with the major component silver. The concentration of Ag, presumably the main constituent of the coins, varies from 55% to 99%. This significant variation in the concentration of the major constituent reveals the economical difficulties encountered by each dynasty. It could be also attributed to differences in the composition of the silver mines used to strike the coins in different locations. That fineness evolution also reflects the poor quality of the control practices during this medieval period. In order to verify the ability of PIXE analytical method to distinguish between apparently similar coins, we applied hierarchical cluster analysis to our results to classify them into different subgroups of similar elemental composition.« less

Treating Brain Tumor with Microbeam Radiation Generated by a Compact Carbon-Nanotube-Based Irradiator: Initial Radiation Efficacy Study.

PubMed

Yuan, Hong; Zhang, Lei; Frank, Jonathan E; Inscoe, Christina R; Burk, Laurel M; Hadsell, Mike; Lee, Yueh Z; Lu, Jianping; Chang, Sha; Zhou, Otto

2015-09-01

Microbeam radiation treatment (MRT) using synchrotron radiation has shown great promise in the treatment of brain tumors, with a demonstrated ability to eradicate the tumor while sparing normal tissue in small animal models. With the goal of expediting the advancement of MRT research beyond the limited number of synchrotron facilities in the world, we recently developed a compact laboratory-scale microbeam irradiator using carbon nanotube (CNT) field emission-based X-ray source array technology. The focus of this study is to evaluate the effects of the microbeam radiation generated by this compact irradiator in terms of tumor control and normal tissue damage in a mouse brain tumor model. Mice with U87MG human glioblastoma were treated with sham irradiation, low-dose MRT, high-dose MRT or 10 Gy broad-beam radiation treatment (BRT). The microbeams were 280 μm wide and spaced at 900 μm center-to-center with peak dose at either 48 Gy (low-dose MRT) or 72 Gy (high-dose MRT). Survival studies showed that the mice treated with both MRT protocols had a significantly extended life span compared to the untreated control group (31.4 and 48.5% of life extension for low- and high-dose MRT, respectively) and had similar survival to the BRT group. Immunostaining on MRT mice demonstrated much higher DNA damage and apoptosis level in tumor tissue compared to the normal brain tissue. Apoptosis in normal tissue was significantly lower in the low-dose MRT group compared to that in the BRT group at 48 h postirradiation. Interestingly, there was a significantly higher level of cell proliferation in the MRT-treated normal tissue compared to that in the BRT-treated mice, indicating rapid normal tissue repairing process after MRT. Microbeam radiation exposure on normal brain tissue causes little apoptosis and no macrophage infiltration at 30 days after exposure. This study is the first biological assessment on MRT effects using the compact CNT-based irradiator. It provides an alternative technology that can enable widespread MRT research on mechanistic studies using a preclinical model, as well as further translational research towards clinical applications.

Laser-induced radiation microbeam technology and simultaneous real-time fluorescence imaging in live cells.

PubMed

Botchway, Stanley W; Reynolds, Pamela; Parker, Anthony W; O'Neill, Peter

2012-01-01

The use of nano- and microbeam techniques to induce and identify subcellular localized energy deposition within a region of a living cell provides a means to investigate the effects of low radiation doses. Particularly within the nucleus where the propagation and processing of deoxyribonucleic acid (DNA) damage (and repair) in both targeted and nontargeted cells, the latter being able to study cell-cell (bystander) effects. We have pioneered a near infrared (NIR) femtosecond laser microbeam to mimic ionizing radiation through multiphoton absorption within a 3D femtoliter volume of a highly focused Gaussian laser beam. The novel optical microbeam mimics both complex ionizing and UV-radiation-type cell damage including double strand breaks (DSBs). Using the microbeam technology, we have been able to investigate the formation of DNA DSB and subsequent recruitment of repair proteins to the submicrometer size site of damage introduced in viable cells. The use of a phosphorylated H2AX (γ-H2AX a marker for DSBs, visualized by immunofluorescent staining) and real-time imaging of fluorescently labeling proteins, the dynamics of recruitment of repair proteins in viable mammalian cells can be observed. Here we show the recruitment of ATM, p53 binding protein 1 (53BP1), and RAD51, an integral protein of the homologous recombination process in the DNA repair pathway and Ku-80-GFP involved in the nonhomologous end joining (NHEJ) pathway as exemplar repair process to show differences in the repair kinetics of DNA DSBs. The laser NIR multiphoton microbeam technology shows persistent DSBs at later times post laser irradiation which are indicative of DSBs arising at replication presumably from UV photoproducts or clustered damage containing single strand breaks (SSBs) that are also observed. Effects of the cell cycle may also be investigated in real time. Postirradiation and fixed cells studies show that in G1 cells a fraction of multiphoton laser-induced DSBs is persistent for >6h in addition to those induced at replication demonstrating the broad range of timescales taken to repair DNA damage. Copyright © 2012 Elsevier Inc. All rights reserved.

Electrochemical vs X-ray Spectroscopic Measurements of NiFe(CN)6 Crystals

NASA Astrophysics Data System (ADS)

Peecher, Benjamin; Hampton, Jennifer

Pseudocapacitive materials like hexacyanoferrate have greater energy storage capabilities than standard capacitors while maintaining an ability to charge and discharge quickly. We modify the surface of an electrodeposited Ni thin film with a layer of hexacyanoferrate. Charging and discharging these modified films using cyclic voltammetry (CV) allows us to measure the electrochemically active Fe in the film. To determine how closely this resembles the full amount of Fe in the film, we measure the films' composition using particle-induced x-ray emission (PIXE). We also vary the amount of Ni deposited, both to compare the electrolysis value of charge deposited to the PIXE measurement of Ni in the film, and also to measure how varying the thickness of the Ni surface affects the presence of Fe in the film. Comparisons of the CV and PIXE measurements show agreement in Ni levels but disagreement in Fe levels. PIXE measurements of Fe in the film have positive correlation with Ni in the film. This correlation between PIXE measurements of Ni and Fe suggests that PIXE provides a reliable measure of Fe in the film. This implies that a variable proportion of total Fe in a given film is electrochemically active. This research was made possible by the Hope College Department of Physics Frissel Research Fund and the National Science Foundation under Grants RUI-DMR-1104725, MRI-CHE-0959282, and MRI/RUI-PHY-0319523.

Proton-Induced X-Ray Emission Analysis of Crematorium Emissions

NASA Astrophysics Data System (ADS)

Ali, Salina; Nadareski, Benjamin; Yoskowitz, Joshua; Labrake, Scott; Vineyard, Michael

2014-09-01

There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-MeV protons from the 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury in the aerosol samples. The lower limit of detection for airborne mercury in this experiment was approximately 0.2 ng / m3. The PIXE analysis of the soil samples showed the presence of elements commonly found in soil (Si, K, Ca, Ti, Mn, Fe), but no trace of mercury. There has been considerable debate in recent years about possible mercury emissions from crematoria due to amalgam tooth restorations. We have performed a proton-induced X-ray emission (PIXE) analysis of aerosol and soil samples taken near the Vale Cemetery Crematorium in Schenectady, NY, to address this concern. The aerosol samples were collected on the roof of the crematorium using a nine-stage, cascade impactor that separates the particulate matter by aerodynamic diameter and deposits it onto thin Kapton foils. The soil samples were collected at several different distances from the crematorium and compressed into pellets with a hydraulic press. The Kapton foils containing the aerosol samples and the soil pellets were bombarded with 2.2-MeV protons from the 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory. We measured significant concentrations of sulfur, phosphorus, potassium, calcium, and iron, but essentially no mercury in the aerosol samples. The lower limit of detection for airborne mercury in this experiment was approximately 0.2 ng / m3. The PIXE analysis of the soil samples showed the presence of elements commonly found in soil (Si, K, Ca, Ti, Mn, Fe), but no trace of mercury. Union College Department of Physics and Astronomy.

Range verification for eye proton therapy based on proton-induced x-ray emissions from implanted metal markers

NASA Astrophysics Data System (ADS)

La Rosa, Vanessa; Kacperek, Andrzej; Royle, Gary; Gibson, Adam

2014-06-01

Metal fiducial markers are often implanted on the back of the eye before proton therapy to improve target localization and reduce patient setup errors. We aim to detect characteristic x-ray emissions from metal targets during proton therapy to verify the treatment range accuracy. Initially gold was chosen for its biocompatibility properties. Proton-induced x-ray emissions (PIXE) from a 15 mm diameter gold marker were detected at different penetration depths of a 59 MeV proton beam at the CATANA proton facility at INFN-LNS (Italy). The Monte Carlo code Geant4 was used to reproduce the experiment and to investigate the effect of different size markers, materials, and the response to both mono-energetic and fully modulated beams. The intensity of the emitted x-rays decreases with decreasing proton energy and thus decreases with depth. If we assume the range to be the depth at which the dose is reduced to 10% of its maximum value and we define the residual range as the distance between the marker and the range of the beam, then the minimum residual range which can be detected with 95% confidence level is the depth at which the PIXE peak is equal to 1.96 σbkg, which is the standard variation of the background noise. With our system and experimental setup this value is 3 mm, when 20 GyE are delivered to a gold marker of 15 mm diameter. Results from silver are more promising. Even when a 5 mm diameter silver marker is placed at a depth equal to the range, the PIXE peak is 2.1 σbkg. Although these quantitative results are dependent on the experimental setup used in this research study, they demonstrate that the real-time analysis of the PIXE emitted by fiducial metal markers can be used to derive beam range. Further analysis are needed to demonstrate the feasibility of the technique in a clinical setup.

Ion beam analysis of rubies and their simulants

NASA Astrophysics Data System (ADS)

Juncomma, U.; Intarasiri, S.; Bootkul, D.; Tippawan, U.

2014-07-01

Ion beam analysis (IBA) is a set of well known powerful analytical techniques which use energetic particle beam as a probe. Among them, two techniques are suitable for gemological analysis, i.e., Particle Induced X-rays Emission (PIXE) and Ionoluminescence (IL). We combine these two techniques for the investigations of rubies and their simulants. The main objective is to find a reference fingerprint of these gemstones. The data are collected from several natural rubies, synthetic rubies, red spinels, almandine garnets and rubellite which very much resemble and are difficult to distinguish with the gemologist loupe. From our measurements, due to their different crystal structures and compositions, can be clearly distinguished by the IL and PIXE techniques. The results show that the PIXE spectra consist of a few dominant lines of the host matrix elements of each gemstone and some weaker lines due to trace elements of transition metals. PIXE can easily differentiate rubies from other stones by evaluating their chemical compositions. It is noticed that synthetic rubies generally contain fewer impurities, lower iron and higher chromium than the natural ones. Moreover, the IL spectrum of ruby is unique and different from those of others stones. The typical spectrum of ruby is centered at 694 nm, with small sidebands that can be ascribed to a Cr3+ emission spectrum which is dominated by an R-line at the extreme red end of the visible part of the electromagnetic spectrum. Although the spectrum of synthetic ruby is centered at the same wavelength, the peak is stronger due to higher concentration of Cr and lower concentration of Fe than for natural rubies. For spinel, the IL spectrum shows strong deformation where the R-line is split due to the presence of MgO. For rubellite, the peak center is shifted to 692 nm which might be caused by the replacement of Mn3+ at the Al3+ site of the host structure. It is noticed that almandine garnet is not luminescent due to the idiochromatic nature of the stone.

Report about the Solar Eclipse on August 11, 1999

NASA Astrophysics Data System (ADS)

1999-08-01

This webpage provides information about the total eclipse on Wednesday, August 11, 1999, as it was seen by ESO staff, mostly at or near the ESO Headquarters in Garching (Bavaria, Germany). The zone of totality was about 108 km wide and the ESO HQ were located only 8 km south of the line of maximum totality. The duration of the phase of totality was about 2 min 17 sec. The weather was quite troublesome in this geographical area. Heavy clouds moved across the sky during the entire event, but there were also some holes in between. Consequently, sites that were only a few kilometres from each other had very different viewing conditions. Some photos and spectra of the eclipsed Sun are displayed below, with short texts about the circumstances under which they were made. Please note that reproduction of pictures on this webpage is only permitted, if the author is mentioned as source. Information made available before the eclipse is available here. Eclipse Impressions at the ESO HQ Photo by Eddy Pomaroli Preparing for the Eclipse Photo: Eddy Pomaroli [JEG: 400 x 239 pix - 116k] [JPEG: 800 x 477 pix - 481k] [JPEG: 3000 x 1789 pix - 3.9M] Photo by Eddy Pomaroli During the 1st Partial Phase Photo: Eddy Pomaroli [JPEG: 400 x 275 pix - 135k] [JPEG: 800 x 549 pix - 434k] [JPEG: 2908 x 1997 pix - 5.9M] Photo by Hamid Mehrgan Heavy Clouds Above Digital Photo: Hamid Mehrgan [JPEG: 400 x 320 pix - 140k] [JPEG: 800 x 640 pix - 540k] [JPEG: 1280 x 1024 pix - 631k] Photo by Olaf Iwert Totality Approaching Digital Photo: Olaf Iwert [JPEG: 400 x 320 pix - 149k] [JPEG: 800 x 640 pix - 380k] [JPEG: 1280 x 1024 pix - 536k] Photo by Olaf Iwert Beginning of Totality Digital Photo: Olaf Iwert [JPEG: 400 x 236 pix - 86k] [JPEG: 800 x 471 pix - 184k] [JPEG: 1280 x 753 pix - 217k] Photo by Olaf Iwert A Happy Eclipse Watcher Digital Photo: Olaf Iwert [JPEG: 400 x 311 pix - 144k] [JPEG: 800 x 622 pix - 333k] [JPEG: 1280 x 995 pix - 644k] ESO HQ Eclipse Video Clip [MPEG-version] ESO HQ Eclipse Video Clip (2425 frames/01:37 min) [MPEG Video; 160x120 pix; 2.2M] [MPEG Video; 320x240 pix; 4.4Mb] [RealMedia; streaming; 33kps] [RealMedia; streaming; 200kps] This Video Clip was prepared from a "reportage" of the event at the ESO HQ that was transmitted in real-time to ESO-Chile via ESO's satellite link. It begins with some sequences of the first partial phase and the eclipse watchers. Clouds move over and the landscape darkens as the phase of totality approaches. The Sun is again visible at the very moment this phase ends. Some further sequences from the second partial phase follow. Produced by Herbert Zodet. Dire Forecasts The weather predictions in the days before the eclipse were not good for Munich and surroundings. A heavy front with rain and thick clouds that completely covered the sky moved across Bavaria the day before and the meteorologists predicted a 20% chance of seeing anything at all. On August 10, it seemed that the chances were best in France and in the western parts of Germany, and much less close to the Alps. This changed to the opposite during the night before the eclipse. Now the main concern in Munich was a weather front approaching from the west - would it reach this area before the eclipse? The better chances were then further east, nearer the Austrian border. Many people travelled back and forth along the German highways, many of which quickly became heavily congested. Preparations About 500 persons, mostly ESO staff with their families and friends, were present at the ESO HQ in the morning of August 11. Prior to the eclipse, they received information about the various aspects of solar eclipses and about the specific conditions of this one in the auditorium. Protective glasses were handed out and it was the idea that they would then follow the eclipse from outside. In view of the pessimistic weather forecasts, TV sets had been set up in two large rooms, but in the end most chose to watch the eclipse from the terasse in front of the cafeteria and from the area south of the building. Several telescopes were set up among the trees and on the adjoining field (just harvested). Clouds and Holes It was an unusual solar eclipse experience. Heavy clouds were passing by with sudden rainshowers, but fortunately there were also some holes with blue sky in between. While much of the first partial phase was visible through these, some really heavy clouds moved in a few minutes before the total phase, when the light had begun to fade. They drifted slowly - too slowly! - towards the east and the corona was never seen from the ESO HQ site. From here, the view towards the eclipsed Sun only cleared at the very instant of the second "diamond ring" phenomenon. This was beautiful, however, and evidently took most of the photographers by surprise, so very few, if any, photos were made of this memorable moment. Temperature Curve by Benoit Pirenne Temperature Curve on August 11 [JPEG: 646 x 395 pix - 35k] Measured by Benoit Pirenne - see also his meteorological webpage Nevertheless, the entire experience was fantastic - there were all the expected effects, the darkness, the cool air, the wind and the silence. It was very impressive indeed! And it was certainly a unique day in ESO history! Carolyn Collins Petersen from "Sky & Telescope" participated in the conference at ESO in the days before and watched the eclipse from the "Bürgerplatz" in Garching, about 1.5 km south of the ESO HQ. She managed to see part of the totality phase and filed some dramatic reports at the S&T Eclipse Expedition website. They describe very well the feelings of those in this area! Eclipse Photos Several members of the ESO staff went elsewhere and had more luck with the weather, especially at the moment of totality. Below are some of their impressive pictures. Eclipse Photo by Philippe Duhoux First "Diamond Ring" [JPEG: 400 x 292 pix - 34k] [JPEG: 800 x 583 pix - 144k] [JPEG: 2531 x 1846 pix - 1.3M] Eclipse Photo by Philippe Duhoux Totality [JPEG: 400 x 306 pix - 49k] [JPEG: 800 x 612 pix - 262k] [JPEG: 3039 x 1846 pix - 3.6M] Eclipse Photo by Philippe Duhoux Second "Diamond Ring" [JPEG: 400 x 301 pix - 34k] [JPEG: 800 x 601 pix - 163k] [JPEG: 2905 x 2181 pix - 2.0M] The Corona (Philippe Duhoux) "For the observation of the eclipse, I chose a field on a hill offering a wide view towards the western horizon and located about 10 kilometers north west of Garching." "While the partial phase was mostly cloudy, the sky went clear 3 minutes before the totality and remained so for about 15 minutes. Enough to enjoy the event!" "The images were taken on Agfa CT100 colour slide film with an Olympus OM-20 at the focus of a Maksutov telescope (f = 1000 mm, f/D = 10). The exposure times were automatically set by the camera. During the partial phase, I used an off-axis mask of 40 mm diameter with a mylar filter ND = 3.6, which I removed for the diamond rings and the corona." Note in particular the strong, detached protuberances to the right of the rim, particularly noticeable in the last photo. Eclipse Photo by Cyril Cavadore Totality [JPEG: 400 x 360 pix - 45k] [JPEG: 800 x 719 pix - 144k] [JPEG: 908 x 816 pix - 207k] The Corona (Cyril Cavadore) "We (C.Cavadore from ESO and L. Bernasconi and B. Gaillard from Obs. de la Cote d'Azur) took this photo in France at Vouzier (Champagne-Ardennes), between Reims and Nancy. A large blue opening developed in the sky at 10 o'clock and we decided to set up the telescope and the camera at that time. During the partial phase, a lot of clouds passed over, making it hard to focus properly. Nevertheless, 5 min before totality, a deep blue sky opened above us, allowing us to watch it and to take this picture. 5-10 Minutes after the totality, the sky was almost overcast up to the 4th contact". "The image was taken with a 2x2K (14 µm pixels) Thomson "homemade" CCD camera mounted on a CN212 Takahashi (200 mm diameter telescope) with a 1/10.000 neutral filter. The acquisition software set exposure time (2 sec) and took images in a complete automated way, allowing us to observe the eclipse by naked eye or with binoculars. To get as many images as possible during totality, we use binning 2x2 to reduce the readout time to 19 sec. Afterward, one of the best image was flat-fielded and processed with a special algorithm that modelled a fit the continuous component of the corona and then subtracted from the original image. The remaining details were enhanced by unsharp masking and added to the original image. Finally, gaussian histogram equalization was applied". Eclipse Photo by Eddy Pomaroli Second "Diamond Ring" [JPEG: 400 x 438 pix - 129k] [JPEG: 731 x 800 pix - 277k] [JPEG: 1940 x 2123 pix - 2.3M] Diamond Ring at ESO HQ (Eddy Pomaroli) "Despite the clouds, we saw the second "diamond ring" from the ESO HQ. In a sense, we were quite lucky, since the clouds were very heavy during the total phase and we might easily have missed it all!". "I used an old Minolta SRT-101 camera and a teleobjective (450 mm; f/8). The exposure was 1/125 sec on Kodak Elite 100 (pushed to 200 ASA). I had the feeling that the Sun would become visible and had the camera pointed, by good luck in the correct direction, as soon as the cloud moved away". Eclipse Photo by Roland Reiss First Partial Phase [JPEG: 400 x 330 pix - 94k] [JPEG: 800 x 660 pix - 492k] [JPEG: 3000 x 2475 pix - 4.5M] End of First Partial Phase (Roland Reiss) "I observed the eclipse from my home in Garching. The clouds kept moving and this was the last photo I was able to obtain during the first partial phase, before they blocked everything". "The photo is interesting, because it shows two more images of the eclipsed Sun, below the overexposed central part. In one of them, the remaining, narrow crescent is particularly well visible. They are caused by reflections in the camera. I used a Minolta camera and a Fuji colour slide film". Eclipse Spectra Some ESO people went a step further and obtained spectra of the Sun at the time of the eclipse. Eclipse Spectrum by Roland Reiss Coronal Spectrum [JPEG: 400 x 273 pix - 94k] [JPEG: 800 x 546 pix - 492k] [JPEG: 3000 x 2046 pix - 4.5M] Coronal Spectrum (CAOS Group) The Club of Amateurs in Optical Spectroscopy (with Carlos Guirao Sanchez, Gerardo Avila and Jesus Rodriguez) obtained a spectrum of the solar corona from a site in Garching, about 2 km south of the ESO HQ. "This is a plot of the spectrum and the corresponding CCD image that we took during the total eclipse. The main coronal lines are well visible and have been identified in the figure. Note in particular one at 6374 Angstrom that was first ascribed to the mysterious substance "Coronium". We now know that it is emitted by iron atoms that have lost nine electrons (Fe X)". The equipment was: * Telescope: Schmidt Cassegrain F/6.3; Diameter: 250 mm * FIASCO Spectrograph: Fibre: 135 micron core diameter F = 100 mm collimator, f = 80 mm camera; Grating: 1300 gr/mm blazed at 500 nm; SBIG ST8E CCD camera; Exposure time was 20 sec. Eclipse Spectrum by Bob Fosbury Chromospheric Spectrum [JPEG: 120 x 549 pix - 20k] Chromospheric and Coronal Spectra (Bob Fosbury) "The 11 August 1999 total solar eclipse was seen from a small farm complex called Wolfersberg in open fields some 20km ESE of the centre of Munich. It was chosen to be within the 2min band of totality but likely to be relatively unpopulated". "There were intermittent views of the Sun between first and second contact with quite a heavy rainshower which stopped 9min before totality. A large clear patch of sky revealed a perfect view of the Sun just 2min before second contact and it remained clear for at least half an hour after third contact". "The principal project was to photograph the spectrum of the chromosphere during totality using a transmission grating in front of a moderate telephoto lens. The desire to do this was stimulated by a view of the 1976 eclipse in Australia when I held the same grating up to the eclipsed Sun and was thrilled by the view of the emission line spectrum. The trick now was to get the exposure right!". "A sequence of 13 H-alpha images was combined into a looping movie. The exposure times were different, but some attempt has been made to equalise the intensities. The last two frames show the low chromosphere and then the photosphere emerging at 3rd contact. The [FeX] coronal line can be seen on the left in the middle of the sequence. I used a Hasselblad camera and Agfa slide film (RSX II 100)".

Cell cycle tracking for irradiated and unirradiated bystander cells in a single colony with exposure to a soft X-ray microbeam.

PubMed

Kaminaga, Kiichi; Noguchi, Miho; Narita, Ayumi; Hattori, Yuya; Usami, Noriko; Yokoya, Akinari

2016-11-01

To establish a new experimental technique to explore the photoelectric and subsequent Auger effects on the cell cycles of soft X-ray microbeam-irradiated cells and unirradiated bystander cells in a single colony. Several cells located in the center of a microcolony of HeLa-Fucci cells consisting of 20-80 cells were irradiated with soft X-ray (5.35 keV) microbeam using synchrotron radiation as a light source. All cells in the colony were tracked for 72 h by time-lapse microscopy imaging. Cell cycle progression, division, and death of each cell in the movies obtained were analyzed by pedigree assay. The number of cell divisions in the microcolony was also determined. The fates of these cells were clarified by tracking both irradiated and unirradiated bystander cells. Irradiated cells showed significant cell cycle retardation, explosive cell death, or cell fusion after a few divisions. These serious effects were also observed in 15 and 26% of the bystander cells for 10 and 20 Gy irradiation, respectively, and frequently appeared in at least two daughter or granddaughter cells from a single-parent cell. We successfully tracked the fates of microbeam-irradiated cells and unirradiated bystander cells with live cell recordings, which have revealed the dynamics of soft X-ray irradiated and unirradiated bystander cells for the first time. Notably, cell deaths or cell cycle arrests frequently arose in closely related cells. These details would not have been revealed by a conventional immunostaining imaging method. Our approach promises to reveal the dynamic cellular effects of soft X-ray microbeam irradiation and subsequent Auger processes from various endpoints in future studies.

Trace element analysis by PIXE in several biomedical fields

NASA Astrophysics Data System (ADS)

Weber, G.; Robaye, G.; Bartsch, P.; Collignon, A.; Beguin, Y.; Roelandts, I.; Delbrouck, J. M.

1984-04-01

Since 1980 in the University of Liége trace element analysis by PIXE has been developed in several directions, among these: the elemental composition of lung parenchyma, hilar lymph nodes, blood content in hematological disorders and renal insufficiency. The content in trace elements of lung tumor and surrounding tissue is measured and compared to similar content previously obtained on unselected patients of comparable ages. The normalization of the bromine deficiency observed in hemodialized patients is achieved by using a dialyzing bath doped with NaBr in order to obtain a normal bromine level of 5.7 μg/ml. The content of Cu, Zn, Br and Se in blood serum from more than 100 patients suffering from malignant hemopathy has been measured. The results are compared with a reference group. These oligoelements have also been measured sequentially for patients under intensive chemotherapy in acute myeloid leukemia.

Trends and sources for heavy metals in urban atmosphere

NASA Astrophysics Data System (ADS)

Kemp, Kåre

2002-04-01

The concentrations of a number of heavy metals in the air in three Danish cities have been measured by means of PIXE for more than two decades. The well-known capability of PIXE for fast and efficient analysis of aerosol samples has been employed for analysis of daily samples from several sites during the whole period. The main sources are traffic, domestic heating and long-range transport. Source apportionment and trends for single metals are assessed by means of simple statistical methods. The most striking change has occurred for the Pb concentration, which is reduced by almost a factor of 100 following the reduction of the Pb content in petrol. The main source of Cu, Cr and Zn is the traffic. The concentrations of these elements have been slightly increasing. The concentrations for most of the other heavy metals, which originate mainly from sources outside the cities, have been decreasing.

An efficient approach to integrated MeV ion imaging.

PubMed

Nikbakht, T; Kakuee, O; Solé, V A; Vosuoghi, Y; Lamehi-Rachti, M

2018-03-01

An ionoluminescence (IL) spectral imaging system, besides the common MeV ion imaging facilities such as µ-PIXE and µ-RBS, is implemented at the Van de Graaff laboratory of Tehran. A versatile processing software is required to handle the large amount of data concurrently collected in µ-IL and common MeV ion imaging measurements through the respective methodologies. The open-source freeware PyMca, with image processing and multivariate analysis capabilities, is employed to simultaneously process common MeV ion imaging and µ-IL data. Herein, the program was adapted to support the OM_DAQ listmode data format. The appropriate performance of the µ-IL data acquisition system is confirmed through a case study. Moreover, the capabilities of the software for simultaneous analysis of µ-PIXE and µ-RBS experimental data are presented. Copyright © 2017 Elsevier B.V. All rights reserved.

Study of new sheep bone and Zn/Ca ratio around TiAlV screw: PIXE RBS analysis

NASA Astrophysics Data System (ADS)

Guibert, G.; Munnik, F.; Langhoff, J. D.; Von Rechenberg, B.; Buffat, Ph. A.; Laub, D.; Faber, L.; Ducret, F.; Gerber, I.; Mikhailov, S.

2008-03-01

This study reports on in vivo particle induced X-ray emission (PIXE) measurements combined with Rutherford backscattering spectroscopy (RBS) analyses of new remodeled sheep bone formed around TiAlV screws. The implants (screws) were anodized by a modified TiMax™ process. The interface between the implant and the bone was carefully investigated. [Zn]/[Ca] in-depth composition profiles as well as Ca, Fe elemental maps were recorded. The thickness of new bone formed around the screw reached 300-400 μm. Osteon and Osteoid phases were identified in the new bone. A higher [Zn]/[Ca] ratio was observed in the new bone as compared to the mature bone. Blood vessels were observed in the bone in close contact with the screw. This study shows the potential of ion beam analysis for biological and biomedical characterization.

Beam characterisation of the KIRAMS electron microbeam system.

PubMed

Sun, G M; Kim, E H; Song, K B; Jang, M

2006-01-01

An electron microbeam system has been installed at the Korea Institute of Radiological and Medical Sciences (KIRAMS) for use in radiation biology studies. The electron beam is produced from a commercial electron gun, and the beam size is defined by a 5 microm diameter pinhole. Beam energy can be varied in the range of 1-100 keV, covering a range of linear energy transfer from 0.4 to 12.1 keV microm-1. The micrometer-sized electron beam selectively irradiates cells cultured in a Mylar-bottomed dish. The positioning of target cells one by one onto the beam exit is automated, as is beam shooting. The electron beam entering the target cells has been calibrated using a Passivated Implanted Planar Silicon (PIPS) detector. This paper describes the KIRAMS microbeam cell irradiation system and its beam characteristics.

MEMS sensing and control: an aerospace perspective

NASA Astrophysics Data System (ADS)

Schoess, Jeffrey N.; Arch, David K.; Yang, Wei; Cabuz, Cleopatra; Hocker, Ben; Johnson, Burgess R.; Wilson, Mark L.

2000-06-01

Future advanced fixed- and rotary-wing aircraft, launch vehicles, and spacecraft will incorporate smart microsensors to monitor flight integrity and provide flight control inputs. This paper provides an overview of Honeywell's MEMS technologies for aerospace applications of sensing and control. A unique second-generation polysilicon resonant microbeam sensor design is described. It incorporates a micron-level vacuum-encapsulated microbeam to optically sense aerodynamic parameters and to optically excite the sensor pick off: optically excited self-resonant microbeams form the basis for a new class of versatile, high- performance, low-cost MEMS sensors that uniquely combine silicon microfabrication technology with optoelectronic technology that can sense dynamic pressure, acceleration forces, acoustic emission, and many other aerospace parameters of interest. Honeywell's recent work in MEMS tuning fork gyros for inertial sensing and a MEMS free- piston engine are also described.

Analysis of memory consolidation and evocation in rats by proton induced X-ray emission

NASA Astrophysics Data System (ADS)

Jobim, P. F. C.; dos Santos, C. E. I.; Maurmann, N.; Reolon, G. K.; Debastiani, R.; Pedroso, T. R.; Carvalho, L. M.; Dias, J. F.

2014-08-01

It is well known that trace elements such as Mg, Ca, Fe, Cu and Zn have a key role in synapse plasticity and learning. Learning process is conventionally divided in three distinct and complementary stages: memory acquisition, consolidation and evocation. Consolidation is the stabilization of the synaptic trace formed by acquisition, while evocation is the recall of this trace. Ion-based techniques capable of providing information concerning the elemental composition of organic tissues may be helpful to improve our understanding on memory consolidation and evocation processes. In particular, the Particle-Induced X-ray Emission (PIXE) technique can be used to analyze different biological tissues with good accuracy. In this work we explore the versatility of PIXE to measure the elemental concentrations in rat brain tissues in order to establish any possible correlation between them and the memory consolidation and evocation processes. To this end, six groups of middle-age male Wistar rats were trained and tested in a step-down Inhibitory Avoidance conditioning. After the behavior tests, the animals were decapitated in accordance with the legal procedures and their brains were removed and dissected for the PIXE analyses. The results demonstrated that there are differences in the elemental concentration among the groups and such variations may be associated with their availability to the learning processes (by memory consolidation and evocation). Moreover, the control groups circumvent the possibility that a non-specific event involved in learning tasks cause such variations. Our results suggest that PIXE may be a useful tool to investigate memory consolidation and evocation in animal models.

Element-based prognostics of occupational pneumoconiosis using micro-proton-induced X-ray emission analysis.

PubMed

He, Xiaodong; Shen, Hao; Chen, Zidan; Rong, Caicai; Ren, Minqin; Hou, Likun; Wu, Chunyan; Mao, Ling; Lu, Quan; Su, Bo

2017-12-01

Pneumoconiosis is an occupational disease accompanied by long-term lung impairment, for which prediction of prognosis is poorly understood because of the complexity of the inhaled particles. Micro-proton-induced X-ray emission (micro-PIXE) analysis, which is advantageous for high-sensitivity, two-dimensional element mapping of lung tissues, was used to investigate element-based predictive factors of prognosis in Chinese patients with welder's and coal miner's pneumoconiosis. Chest radiographs and lung function tests showed that most of the coal miners deteriorated, whereas symptoms in some welders were alleviated after 5 yr, as determined by comparing percent vital capacity (%VC) and forced expiratory volume in the 1st second over forced vital capacity (FEV1.0/FVC) to values taken at the initial diagnosis. Micro-PIXE analysis suggested that the most abundant particulates in welder's pneumoconiosis were Fe, Mn, and Ti (metallic oxide),which were accompanied by particulates containing Si, Al, and Ca (aluminum silicate) or only Si (SiO 2 ); the most abundant particulates in coal miner's pneumoconiosis were composed of C, Si, Al, K, and Ti, which were accompanied by particulates containing Ca or Fe. Particulates containing Al, Si, S, K, Ca, and Ti (orthoclase and anorthite) were correlated with severity of fibrosis. Multivariable linear regression suggested that long-term FEV1.0/FVC decrease was independently associated with Si and smoking index, whereas %VC decrease was associated with Si and Ti. A risk index comprised of these factors was developed to predict the prognosis of pneumoconiosis. Micro-PIXE analysis is feasible for the evaluation of elemental composition and dust exposure, especially for patients whose exposure is mixed or uncertain. Copyright © 2017 the American Physiological Society.

Development of economic MeV-ion microbeam technology at Chiang Mai University

NASA Astrophysics Data System (ADS)

Singkarat, S.; Puttaraksa, N.; Unai, S.; Yu, L. D.; Singkarat, K.; Pussadee, N.; Whitlow, H. J.; Natyanum, S.; Tippawan, U.

2017-08-01

Developing high technologies but in economic manners is necessary and also feasible for developing countries. At Chiang Mai University, Thailand, we have developed MeV-ion microbeam technology based on a 1.7-MV Tandetron tandem accelerator with our limited resources in a cost-effective manner. Instead of using expensive and technically complex electrostatic or magnetic quadrupole focusing lens systems, we have developed cheap MeV-ion microbeams using programmed L-shaped blade aperture and capillary techniques for MeV ion beam lithography or writing and mapping. The programmed L-shaped blade micro-aperture system consists of a pair of L-shaped movable aperture pieces which are controlled by computer to cut off the ion beam for controlling the beam size down to the micrometer order. The capillary technique utilizes our home-fabricated tapered glass capillaries to realize microbeams. Either system can be installed inside the endstation of the MeV ion beam line of the accelerator. Both systems have been applied to MeV-ion beam lithography or writing of micro-patterns for microfluidics applications to fabricate lab-on-chip devices. The capillary technique is being developed for MeV-ion beam mapping of biological samples. The paper reports details of the techniques and introduces some applications.

Involvement of Alpha-PAK-Interacting Exchange Factor in the PAK1–c-Jun NH2-Terminal Kinase 1 Activation and Apoptosis Induced by Benzo[a]pyrene

PubMed Central

Yoshii, Shigeto; Tanaka, Masamitsu; Otsuki, Yoshiro; Fujiyama, Toshiharu; Kataoka, Hideki; Arai, Hajime; Hanai, Hiroyuki; Sugimura, Haruhiko

2001-01-01

Benzo[a]pyrene [B(a)P], a potent procarcinogen found in combustion products such as diesel exhaust and cigarette smoke, has been recently shown to activate the c-Jun NH2-terminal kinase 1 (JNK1) and induce caspase-3-mediated apoptosis in Hepa1c1c7 cells. However, the molecules of the signaling pathway that control the mitogen-activated protein kinase cascades induced by B(a)P and the interaction between those and apoptosis by B(a)P have not been well defined. We report here that B(a)P promoted Cdc42/Rac1, p21-activated kinase 1 (PAK1), and JNK1 activities in 293T and HeLa cells. Moreover, alpha-PAK-interacting exchange factor (α PIX) mRNA and its protein expression were upregulated by B(a)P. While overexpression of an active mutant of α PIX (ΔCH) facilitated B(a)P-induced activation of Cdc42/Rac1, PAK1, and JNK1, overexpression of mutated αPIX (L383R, L384S), which lacks guanine nucleotide exchange factor activity, SH3 domain-deleted αPIX (Δ SH3), which lacks the ability to bind PAK, kinase-negative PAK1 (K299R), and kinase-negative SEK1 (K220A, K224L) inhibited B(a)P-triggered JNK1 activation. Interestingly, overexpression of αPIX (Δ CH) and a catalytically active mutant PAK1 (T423E) accelerated B(a)P-induced apoptosis in HeLa cells, whereas αPIX (Δ SH3), PAK1 (K299R), and SEK 1 (K220A, K224L) inhibited B(a)P-initiated apoptosis. Finally, a preferential caspase inhibitor, Z-Asp-CH2-DCB, strongly blocked the αPIX (Δ CH)-enhanced apoptosis in cells treated with B(a)P but did not block PAK1/JNK1 activation. Taken together, these results indicate that αPIX plays a crucial role in B(a)P-induced apoptosis through activation of the JNK1 pathway kinases. PMID:11564864

Study of the spatial distribution of mercury in roots of vetiver grass (Chrysopogon zizanioides) by micro-pixe spectrometry.

PubMed

Lomonte, Cristina; Wang, Yaodong; Doronila, Augustine; Gregory, David; Baker, Alan J M; Siegele, Rainer; Kolev, Spas D

2014-01-01

Localization of Hg in root tissues of vetivergrass (Chrysopogon zizanioides) was investigated by micro-Proton Induced X-ray Emission (PIXE) spectrometry to gain a better understanding of Hg uptake and its translocation to the aerial plant parts. Tillers of C. zizanioides were grown in a hydroponic culture for 3 weeks under controlled conditions and then exposed to Hg for 10 days with or without the addition of the chelators (NH(4))(2)S(2)O(3) or KI. These treatments were used to study the effects of these chelators on localization of Hg in the root tissues to allow better understanding of Hg uptake during its assisted-phytoextraction. Qualitative elemental micro-PIXE analysis revealed that Hg was mainly localized in the root epidermis and exodermis, tissues containing suberin in all Hg treatments. Hg at trace levels was localized in the vascular bundle when plants were treated with a mercury solution only. However, higher Hg concentrations were found when the solution also contained (NH(4))(2)S(2)O(3) or KI. This finding is consistent with the observed increase in Hg translocation to the aerial parts of the plants in the case of chemically induced Hg phytoextraction.

Optimization of PIXE-sensitivity for detection of Ti in thin human skin sections

NASA Astrophysics Data System (ADS)

Pallon, Jan; Garmer, Mats; Auzelyte, Vaida; Elfman, Mikael; Kristiansson, Per; Malmqvist, Klas; Nilsson, Christer; Shariff, Asad; Wegdén, Marie

2005-04-01

Modern sunscreens contain particles like TiO2 having sizes of 25-70 nm and acting as a reflecting substance. For cosmetic reasons the particle size is minimized. Questions have been raised to what degree these nano particles penetrate the skin barrier, and how they do affect the human. The EU funded project "Quality of skin as a barrier to ultra-fine particles" - NANODERM has started with the purpose to evaluate the possible risks of TiO2 penetration into vital skin layers. The purpose of the work presented here was to find the optimal conditions for micro-PIXE analysis of Ti in thin skin sections. In the skin region where Ti is expected to be found, the naturally occurring major elements phosphorus, chlorine, sulphur and potassium have steep gradients and thus influence the X-ray background in a non-predictable manner. Based on experimental studies of Ti-exposed human skin sections using proton energies ranging from 1.8-2.55 MeV, the corresponding PIXE detection limits for Ti were calculated. The energy that was found to be the most favourable, 1.9 MeV, was then selected for future studies.

Surface analysis of space telescope material specimens

NASA Technical Reports Server (NTRS)

Fromhold, A. T.; Daneshvar, K.

1985-01-01

Qualitative and quantitative data on Space Telescope materials which were exposed to low Earth orbital atomic oxygen in a controlled experiment during the 41-G (STS-17) mission were obtained utilizing the experimental techniques of Rutherford backscattering (RBS), particle induced X-ray emission (PIXE), and ellipsometry (ELL). The techniques employed were chosen with a view towards appropriateness for the sample in question, after consultation with NASA scientific personnel who provided the material specimens. A group of eight samples and their controls selected by NASA scientists were measured before and after flight. Information reported herein include specimen surface characterization by ellipsometry techniques, a determination of the thickness of the evaporated metal specimens by RBS, and a determination of trace impurity species present on and within the surface by PIXE.

Environmental impact of fertilizer industries evaluated by PIXE

NASA Astrophysics Data System (ADS)

Martín, J. E.; Bolívar, J. P.; Respaldiza, M. A.; García-Tenorio, R.; da Silva, M. F.

1995-12-01

In this paper the environmental impact of several phosphogypsum piles sited in the southwest of Spain is studied using multielemental analysis by PIXE of 12 salt marsh and soil samples collected in their surroundings. The piles are used to store the main by-product formed in the production of phosphoric acid and phosphate fertilizers. The samples collected were bombarded with 2.5 MeV protons from the 3 MV Van de Graaff accelerator in the ITN at Sacavèm (Portugal), and 20 elements from Al to Pb were detected. The results obtained reinforce previous radioanalytical determinations concerning the significant radioactive contamination pathways (leaching or/and dissolution of elements by water from the piles) and the negligible pathways (atmospheric and direct aquatic transport).

Development of technique for three-dimensional visualization of grain boundaries by white X-ray microbeam

NASA Astrophysics Data System (ADS)

Kajiwara, K.; Shobu, T.; Toyokawa, H.; Sato, M.

2014-04-01

A technique for three-dimensional visualization of grain boundaries was developed at BL28B2 at SPring-8. The technique uses white X-ray microbeam diffraction and a rotating slit. Three-dimensional images of small silicon single crystals filled in a plastic tube were successfully obtained using this technique for demonstration purposes. The images were consistent with those obtained by X-ray computed tomography.

Optical Fiber-Tip Sensors Based on In-Situ µ-Printed Polymer Suspended-Microbeams.

PubMed

Yao, Mian; Ouyang, Xia; Wu, Jushuai; Zhang, A Ping; Tam, Hwa-Yaw; Wai, P K A

2018-06-05

Miniature optical fiber-tip sensors based on directly µ-printed polymer suspended-microbeams are presented. With an in-house optical 3D μ-printing technology, SU-8 suspended-microbeams are fabricated in situ to form Fabry⁻Pérot (FP) micro-interferometers on the end face of standard single-mode optical fiber. Optical reflection spectra of the fabricated FP micro-interferometers are measured and fast Fourier transform is applied to analyze the cavity of micro-interferometers. The applications of the optical fiber-tip sensors for refractive index (RI) sensing and pressure sensing, which showed 917.3 nm/RIU to RI change and 4.29 nm/MPa to pressure change, respectively, are demonstrated in the experiments. The sensors and their optical µ-printing method unveil a new strategy to integrate complicated microcomponents on optical fibers toward 'lab-on-fiber' devices and applications.

An automated single ion hit at JAERI heavy ion microbeam to observe individual radiation damage

NASA Astrophysics Data System (ADS)

Kamiya, Tomihiro; Sakai, Takuro; Naitoh, Yutaka; Hamano, Tsuyoshi; Hirao, Toshio

1999-10-01

Microbeam scanning and a single ion hit technique have been combined to establish an automated beam positioning and single ion hit system at the JAERI Takasaki heavy ion microbeam system. Single ion irradiation on preset points of a sample in various patterns can be performed automatically in a short period. The reliability of the system was demonstrated using CR-39 nuclear track detectors. Single ion hit patterns were achieved with a positioning accuracy of 2 μm or less. In measurement of single event transient current using this system, the reduction of the pulse height by accumulation of radiation damages was observed by single ion injection to the same local areas. This technique showed a possibility to get some quantitative information about the lateral displacement of an individual radiation effect in silicon PIN photodiodes. This paper will give details of the irradiation system and present results from several experiments.

Design and Development of a Virtual Facility Tour Using iPIX(TM) Technology

NASA Technical Reports Server (NTRS)

Farley, Douglas L.

2002-01-01

The capabilities of the iPIX virtual tour software, in conjunction with a web-based interface create a unique and valuable system that provides users with an efficient virtual capability to tour facilities while being able to acquire the necessary technical content is demonstrated. A users guide to the Mechanics and Durability Branch's virtual tour is presented. The guide provides the user with instruction on operating both scripted and unscripted tours as well as a discussion of the tours for Buildings 1148, 1205 and 1256 and NASA Langley Research Center. Furthermore, an indepth discussion has been presented on how to develop a virtual tour using the iPIX software interface with conventional html and JavaScript. The main aspects for discussion are on network and computing issues associated with using this capability. A discussion of how to take the iPIX pictures, manipulate them and bond them together to form hemispherical images is also presented. Linking of images with additional multimedia content is discussed. Finally, a method to integrate the iPIX software with conventional HTML and JavaScript to facilitate linking with multi-media is presented.

In vitro study for laser gene transfer in BHK-21 fibroblast cell line

NASA Astrophysics Data System (ADS)

Abdel Aziz, M.; Salem, D. S.; Salama, M. S.; Badr, Y.

2009-02-01

Modifications to our previously introduced system for laser microbeam cell surgery were carried out in the present work to match animal cells. These modifications included: 1- Using other laser system that used before, Excimer laser with 193 and 308 nm wavelengths. The used laser here, is He-Cd with low power and 441.5 nm wavelength in the visible region. 2- Instead of using pulsed laser, we used here CW He-Cd chopped by electrical chopper, which is synchronized with the mechanical motion of the mobile stage with step 40 microns, according to cell dimensions to avoid puncturing the same cell twice. The advantages of the modified here laser setup for gene transfer is: it is less damaging to the sensitive animal cell which has thin cell membrane. The present work aimed to: 1- Design a modified laser microbeam cell surgery, applicable to animal cells, such as fibroblast cells 2- To examine the efficiency of such system. 3- To assure gene transfer and its expression in the used cells. 4- To evaluate the ultra damages produced from using the laser beam as a modality for gene transfer. On the other wards, to introduce: safe, efficient and less damaging modality for gene transfer in animal cells. To achieve these goals, we applied the introduced here home-made laser setup with its synchronized parameters to introduce pBK-CMV phagemid, containing LacZ and neomycin resistance (neor )genes into BHK-21 fibroblast cell line. The results of the present work showed that: 1- Our modified laser microbeam cell surgery setup proved to be useful and efficient tool for gene transfer into fibroblast cells. 2- The presence and expression of LacZ gene was achieved using histochemical LacZ assay. 3- Selection of G418 antibiotic sensitivity assay confirmed the presence and expression towards stability of neor gene with time. 4- Presence of LacZ and neor genes in the genomic DNA of transfected fibroblast cells was indicated using PCR analysis. 5- Transmission electron microscopy indicated that, no ultradamages or changes for cell; membrane, organilles or any component of transfected fibroblast cell as a result of using laser microbeam compared with control cell.

Energy-Dispersive Spectrometry from Then until Now: A Chronology of Innovation

NASA Astrophysics Data System (ADS)

Friel, John J.; Mott, Richard B.

1998-11-01

: As part of the Microbeam Analysis Society (MAS) symposium marking 30 years of energy-dispersive spectrometry (EDS), this article reviews many innovations in the field over those years. Innovations that added a capability previously not available to the microanalyst are chosen for further description. Included are innovations in both X-ray microanalysis and digital imaging using the EDS analyzer.

Use of near infrared femtosecond lasers as sub-micron radiation microbeam for cell DNA damage and repair studies.

PubMed

Botchway, S W; Reynolds, P; Parker, A W; O'Neill, P

2010-01-01

Laser induced radiation microbeam technology for radiobiology research is undergoing rapid growth because of the increased availability and ease of use of femtosecond laser sources. The main processes involved are multiphoton absorption and/or plasma formation. The high peak powers these lasers generate make them ideal tools for depositing sub-micrometer size radiant energy within a region of a living cell nucleus to activate ionising and/or photochemically driven processes. The technique allows questions relating to the effects of low doses of radiation, the propagation and treatment of deoxyribonucleic acid (DNA) damage and repair in individual live cells as well as non-targeted cell to cell effects to be addressed. This mini-review focuses on the use of near infrared (NIR) ca. 800nm radiation to induce damage that is radically different from the early and subsequent ultraviolet microbeam techniques. Ultrafast pulsed NIR instrumentation has many benefits including the ability to eliminate issues of unspecific UV absorption by the many materials prevalent within cells. The multiphoton interaction volume also permits energy deposition beyond the diffraction limit. Work has established that the fundamental process of the damage induced by the ultrashort laser pulses is different to those induced from continuous wave light sources. Pioneering work has demonstrated that NIR laser microbeam radiation can mimic ionising radiation via multiphoton absorption within the 3D femtolitre volume of the highly focused Gaussian beam. This light-matter interaction phenomenon provides a novel optical microbeam probe for mimicking both complex ionising and UV radiation-type cell damage including double strand breaks (DSBs) and base damage. A further advantage of the pulsed laser technique is that it provides further scope for time-resolved experiments. Recently the NIR laser microbeam technique has been used to investigate the recruitment of repair proteins to the sub-micrometre size area of damage in viable cells using both immuno-fluorescent staining of gamma-H2AX (a marker for DSBs) and real-time imaging of GFP-labelled repair proteins including ATM, p53 binding protein 1 (53BP1), RAD51 and Ku 70/80 to elucidate the interaction of the two DNA DSB repair pathways, homologous recombination and the non-homologous end joining pathway. 2010 Elsevier B.V. All rights reserved.

PIXE analysis of sand and soil from Ulaanbaatar and Karakurum, Mongolia

NASA Astrophysics Data System (ADS)

Markwitz, A.; Barry, B.; Shagjjamba, D.

2008-09-01

Twenty-one sand and soil samples were collected at the surface from 22 to 25 June 2007 at sampling sites from Ulaanbaatar to Karakurum, Mongolia. The sand samples were collected from constantly changing sand dunes which may still contain salt from prehistoric oceans. The dry sand and soil samples were processed for PIXE and PIGE analyses. A clear division between soils and sand become apparent in the silicon results. Concentrations of all bulk elements in human habitation samples and of Si, Al, K and Fe in dry lake/flood plain samples are similar to those in the soils and sands. Among elements which could be regarded as being at trace concentrations the average S concentration in the soils is 0.9 g kg-1 whereas it is not detected in the sand samples. Zinc and Cu concentrations are both higher in the soils than the sands and are strongly correlated. A surprising presence of uranium at a concentration of 350 mg kg-1 was detected in the PIXE measurement on one of the dry lake samples. Gamma spectrometry confirmed the presence of U in this sample and also at a lower level in a sample from the lake shore, but in none of the other samples. Further, the gamma spectrometry showed that 238U decay products were present only at a level corresponding to about 3 mg kg-1 U for a system in radioactive equilibrium, a figure which is typical for U in the earth's crust. Disequilibria between 238U and its decay products occur naturally but such a high degree of separation at high concentration would be unique if confirmed. PIXE and PIGE measurements of these samples highlight the difficulty in correlating trace element measurements with occurrence of indicators of sea salt in air particulate samples.

Ion beam analysis of diffusion in heterogeneous materials

NASA Astrophysics Data System (ADS)

Clough, A. S.; Jenneson, P. M.

1998-04-01

Ion-beam analysis has been applied to a variety of problems involving diffusion in heterogeneous materials. An energy loss technique has been used to study both the diffusion of water and the surface segregation of fluoropolymers in polymeric matrices. A scanning micro-beam technique has been developed to allow water concentrations in hydrophilic polymers and cements to be measured together with associated solute elements. It has also been applied to the diffusion of shampoo into hair.

Heavy Ion Microbeam- and Broadbeam-Induced Transients in SiGe HBTs

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Reed, Robert A.; McMorrow, Dale; Vizkelethy, Gyorgy; Ferlet-Cavrois, Veronique; Baggio, Jacques; Duhamel, Olivier; Moen, Kurt A.; Phillips, Stanley D.; Diestelhorst, Ryan M.;

Electrostatically frequency tunable micro-beam-based piezoelectric fluid flow energy harvester

NASA Astrophysics Data System (ADS)

Rezaee, Mousa; Sharafkhani, Naser

2017-07-01

This research investigates the dynamic behavior of a sandwich micro-beam based piezoelectric energy harvester with electrostatically adjustable resonance frequency. The system consists of a cantilever micro-beam immersed in a fluid domain and is subjected to the simultaneous action of cross fluid flow and nonlinear electrostatic force. Two parallel piezoelectric laminates are extended along the length of the micro-beam and connected to an external electric circuit which generates an output power as a result of the micro-beam oscillations. The fluid-coupled structure is modeled using Euler-Bernoulli beam theory and the equivalent force terms for the fluid flow. Fluid induced forces comprise the added inertia force which is evaluated using equivalent added mass and the drag and lift forces which are evaluated using relative velocity and Van der Pol equation. In addition to flow velocity and fluid density, the influence of several design parameters such as external electrical resistance, piezo layer position, and dc voltage on the generated power are investigated by using Galerkin and step by step linearization method. It is shown that for given flowing fluid parameters, i.e., density and velocity, one can adjust the applied dc voltage to tune resonance frequency so that the lock-in phenomenon with steady large amplitude oscillations happens, also by adjusting the harvester parameters including the mechanical and electrical ones, the maximal output power of the harvester becomes possible.

Irradiation of intracerebral 9L gliosarcoma by a single array of microplanar x-ray beams from a synchrotron: balance between curing and sparing

NASA Astrophysics Data System (ADS)

Regnard, Pierrick; LeDuc, Géraldine; Bräuer-Krisch, Elke; Troprès, Irène; Siegbahn, Erik Albert; Kusak, Audrey; Clair, Charlotte; Bernard, Hélène; Dallery, Dominique; Laissue, Jean A.; Bravin, Alberto

2008-02-01

The purpose of this work was the understanding of microbeam radiation therapy at the ESRF in order to find the best compromise between curing of tumors and sparing of normal tissues, to obtain a better understanding of survival curves and to report its efficiency. This method uses synchrotron-generated x-ray microbeams. Rats were implanted with 9L gliosarcomas and the tumors were diagnosed by MRI. They were irradiated 14 days after implantation by arrays of 25 µm wide microbeams in unidirectional mode, with a skin entrance dose of 625 Gy. The effect of using 200 or 100 µm center-to-center spacing between the microbeams was compared. The median survival time (post-implantation) was 40 and 67 days at 200 and 100 µm spacing, respectively. However, 72% of rats irradiated at 100 µm spacing showed abnormal clinical signs and weight patterns, whereas only 12% of rats were affected at 200 µm spacing. In parallel, histological lesions of the normal brain were found in the 100 µm series only. Although the increase in lifespan was equal to 273% and 102% for the 100 and 200 µm series, respectively, the 200 µm spacing protocol provides a better sparing of healthy tissue and may prove useful in combination with other radiation modalities or additional drugs.

Leaf elemental analysis in mycorrhizal post oak seedlings

NASA Astrophysics Data System (ADS)

Boling, B. C.; Naab, F. U.; Smith, D.; Duggan, J. L.; McDaniel, F. D.

2006-09-01

Growth and element assimilation was investigated in the leaves of post oak seedlings exposed to four different treatment combinations of fertilization and ectomycorrhizal inoculation. Element concentration was analyzed via particle-induced X-ray emission spectrometry (PIXE). PIXE detected 10 of the 13 essential macro and micronutrients: P, S, Mg, Ca, K, Cu, Zn, Mn, Fe and Cl. Mean growth and dry weight was significantly different across the treatment groups as well as the mean concentration of Mg, Al, S, K, Ca, Fe, Cu and Zn. The data suggest that fertilization rather than mycorrhizal inoculation had a stronger influence on nutrient uptake. This study is the first to analyze element concentration in post oak and to investigate the potential benefits of mycorrhizal symbiosis in post oak seedlings in terms of nutrient uptake.

Characterization of human kidney stones using micro-PIXE and RBS: a comparative study between two different populations.

PubMed

Pineda-Vargas, C A; Eisa, M E M; Rodgers, A L

2009-03-01

The micro-PIXE and RBS techniques are used to investigate the matrix as well as the trace elemental composition of calcium-rich human tissues on a microscopic scale. This paper deals with the spatial distribution of trace metals in hard human tissues such as kidney stone concretions, undertaken at the nuclear microprobe (NMP) facility. Relevant information about ion beam techniques used for material characterization will be discussed. Mapping correlation between different trace metals to extract information related to micro-regions composition will be illustrated with an application using proton energies of 1.5 and 3.0 MeV and applied to a comparative study for human kidney stone concretions nucleation region analysis from two different population groups (Sudan and South Africa).

Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE-RBS

NASA Astrophysics Data System (ADS)

Zhou, Z.; Zhang, K.; Xia, C. D.; Liu, M. T.; Zhu, J. J.; An, Z.; Bai, B.

2015-03-01

A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271-1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB6 crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907-960 A.D.) had been propagated to the Waguantan kiln site of Guizhou Province in the Yuan Dynasty.

Impact of release dynamics of laser-irradiated polymer micropallets on the viability of selected adherent cells

PubMed Central

Ma, Huan; Mismar, Wael; Wang, Yuli; Small, Donald W.; Ras, Mat; Allbritton, Nancy L.; Sims, Christopher E.; Venugopalan, Vasan

2012-01-01

We use time-resolved interferometry, fluorescence assays and computational fluid dynamics (CFD) simulations to examine the viability of confluent adherent cell monolayers to selection via laser microbeam release of photoresist polymer micropallets. We demonstrate the importance of laser microbeam pulse energy and focal volume position relative to the glass–pallet interface in governing the threshold energies for pallet release as well as the pallet release dynamics. Measurements using time-resolved interferometry show that increases in laser pulse energy result in increasing pallet release velocities that can approach 10 m s−1 through aqueous media. CFD simulations reveal that the pallet motion results in cellular exposure to transient hydrodynamic shear stress amplitudes that can exceed 100 kPa on microsecond timescales, and which produces reduced cell viability. Moreover, CFD simulation results show that the maximum shear stress on the pallet surface varies spatially, with the largest shear stresses occurring on the pallet periphery. Cell viability of confluent cell monolayers on the pallet surface confirms that the use of larger pulse energies results in increased rates of necrosis for those cells situated away from the pallet centre, while cells situated at the pallet centre remain viable. Nevertheless, experiments that examine the viability of these cell monolayers following pallet release show that proper choices for laser microbeam pulse energy and focal volume position lead to the routine achievement of cell viability in excess of 90 per cent. These laser microbeam parameters result in maximum pallet release velocities below 6 m s−1 and cellular exposure of transient hydrodynamic shear stresses below 20 kPa. Collectively, these results provide a mechanistic understanding that relates pallet release dynamics and associated transient shear stresses with subsequent cellular viability. This provides a quantitative, mechanistic basis for determining optimal operating conditions for laser microbeam-based pallet release systems for the isolation and selection of adherent cells. PMID:22158840

Impact of release dynamics of laser-irradiated polymer micropallets on the viability of selected adherent cells.

PubMed

Ma, Huan; Mismar, Wael; Wang, Yuli; Small, Donald W; Ras, Mat; Allbritton, Nancy L; Sims, Christopher E; Venugopalan, Vasan

2012-06-07

We use time-resolved interferometry, fluorescence assays and computational fluid dynamics (CFD) simulations to examine the viability of confluent adherent cell monolayers to selection via laser microbeam release of photoresist polymer micropallets. We demonstrate the importance of laser microbeam pulse energy and focal volume position relative to the glass-pallet interface in governing the threshold energies for pallet release as well as the pallet release dynamics. Measurements using time-resolved interferometry show that increases in laser pulse energy result in increasing pallet release velocities that can approach 10 m s(-1) through aqueous media. CFD simulations reveal that the pallet motion results in cellular exposure to transient hydrodynamic shear stress amplitudes that can exceed 100 kPa on microsecond timescales, and which produces reduced cell viability. Moreover, CFD simulation results show that the maximum shear stress on the pallet surface varies spatially, with the largest shear stresses occurring on the pallet periphery. Cell viability of confluent cell monolayers on the pallet surface confirms that the use of larger pulse energies results in increased rates of necrosis for those cells situated away from the pallet centre, while cells situated at the pallet centre remain viable. Nevertheless, experiments that examine the viability of these cell monolayers following pallet release show that proper choices for laser microbeam pulse energy and focal volume position lead to the routine achievement of cell viability in excess of 90 per cent. These laser microbeam parameters result in maximum pallet release velocities below 6 m s(-1) and cellular exposure of transient hydrodynamic shear stresses below 20 kPa. Collectively, these results provide a mechanistic understanding that relates pallet release dynamics and associated transient shear stresses with subsequent cellular viability. This provides a quantitative, mechanistic basis for determining optimal operating conditions for laser microbeam-based pallet release systems for the isolation and selection of adherent cells.

Differential PIXE for investigating the layer structure of paintings

NASA Astrophysics Data System (ADS)

Mandò, P. A.; Fedi, M. E.; Grassi, N.; Migliori, A.

2005-09-01

This paper reports an example of how the differential PIXE technique can be successfully applied to the investigation of wood or canvas paintings. The work analysed is a famous wood painting by Leonardo da Vinci, the "Madonna dei fusi" (ex-Reford version, 1501), chosen for a pilot study in a wide international project aimed at analysing Leonardo's works of art by means of non-destructive techniques. While illustrating the results obtained concerning the identification of pigments and the discrimination of the stratigraphy of layers, the merits and limits of differential PIXE in general are pointed out.

An extracellular-matrix-specific GEF-GAP interaction regulates Rho GTPase crosstalk for 3D collagen migration.

PubMed

Kutys, Matthew L; Yamada, Kenneth M

2014-09-01

Rho-family GTPases govern distinct types of cell migration on different extracellular matrix proteins in tissue culture or three-dimensional (3D) matrices. We searched for mechanisms selectively regulating 3D cell migration in different matrix environments and discovered a form of Cdc42-RhoA crosstalk governing cell migration through a specific pair of GTPase activator and inhibitor molecules. We first identified βPix, a guanine nucleotide exchange factor (GEF), as a specific regulator of migration in 3D collagen using an affinity-precipitation-based GEF screen. Knockdown of βPix specifically blocks cell migration in fibrillar collagen microenvironments, leading to hyperactive cellular protrusion accompanied by increased collagen matrix contraction. Live FRET imaging and RNAi knockdown linked this βPix knockdown phenotype to loss of polarized Cdc42 but not Rac1 activity, accompanied by enhanced, de-localized RhoA activity. Mechanistically, collagen phospho-regulates βPix, leading to its association with srGAP1, a GTPase-activating protein (GAP), needed to suppress RhoA activity. Our results reveal a matrix-specific pathway controlling migration involving a GEF-GAP interaction of βPix with srGAP1 that is critical for maintaining suppressive crosstalk between Cdc42 and RhoA during 3D collagen migration.

Expert Images for All Audiences: The AstroPix Archive

NASA Astrophysics Data System (ADS)

Hurt, Robert; Llamas, Jacob; Wyatt, Ryan Jason; Christensen, Lars

2018-01-01

The AstroPix project provides one-stop-shopping for an extensive collection of the finest astronomical imagery, sourced from some of the world’s most prominent observatories. The archive is made possible by a grassroots effort to tag publicly-released imagery using the Astronomical Visualization Metadata (AVM) standard, which captures rich contextual information for each image. While the site has been in development for many years, it is now supported under NASA’s Universe of Learning collaboration, and AstroPix has been updated and deployed to cloud services. The AVM tags provide many unique features including spectral color assignments, sky context (using AAS WorldWide Telescope APIs), and direct links to the original source material on the web. The 7,000+ assets currently include imagery provided by Chandra, ESO, GALEX, Herschel, Hubble, NuSTAR, Spitzer, and WISE. The assets are also provided for use in the planetarium community by supporting the Data2Dome (D2D) initiative. AstroPix imagery is designed to be used in a variety of unique ways that benefit formal and informal education as well as astronomers and the general public. Observatories can add their own image archives to AstroPix by tagging their assets and providing a simple XML feed, increasing the value of their data to the community at large.

Ascertaining serum levels of trace elements in melanoma patients using PIXE and HR-ICPMS

NASA Astrophysics Data System (ADS)

Bernardes, S.; Tabacniks, M. H.; Santos, I. D. A. O.; Oliveira, A. F.; Shie, J. N.; Sarkis, J. E. S.; Oliveira, T.

2014-01-01

Melanoma is a serious and deadly form of skin cancer. However, patients' chances of survival and recovery are considerably increased when it is diagnosed and treated in its early stages. In this study, trace element concentrations in serum samples from patients with melanoma were measured using PIXE (Proton Induced X-ray Emission) and HR-ICPMS (High-Resolution Inductively Coupled Plasma Mass Spectrometry), with the purpose of correlating these concentrations with the disease. Blood samples from 30 melanoma patients and 116 healthy donors were collected at São Paulo Hospital (protocol CEP 1036/08 UNIFESP). Relevant clinical information on the patients has also been included in the statistical analysis. Analysis of the control group showed different P and Mg concentrations in individuals above and below 40 years of age. P, S, Ca, Cu and Zn concentrations in healthy individuals differed according to gender, highlighting the necessity to include age and gender variables in the case-control analysis. There were also differences in K, S, Ca and Se concentrations between the control and melanoma groups.

Detection of trace metallic elements in oral lichenoid contact lesions using SR-XRF, PIXE, and XAFS

PubMed Central

Sugiyama, Tomoko; Uo, Motohiro; Wada, Takahiro; Omagari, Daisuke; Komiyama, Kazuo; Miyazaki, Serika; Numako, Chiya; Noguchi, Tadahide; Jinbu, Yoshinori; Kusama, Mikio; Mori, Yoshiyuki

2015-01-01

Oral lichen planus (OLP) and oral lichenoid contact lesions (OLCL) are chronic inflammatory mucocutaneous reactions with a risk of malignant transformation that alter the epithelium. OLP and OLCL have similar clinical and histopathological features and it is difficult to distinguish one from the other. Metallic restorations are suspected to generate OLCLs. Trace metal analysis of OLCL specimens may facilitate the discrimination of symptoms and identification of causative metallic restorations. The purpose of this study was to assess OLCL tissue samples for the prevalence of metallic elements derived from dental restorations, and to discriminate OLCL from OLP by using synchrotron radiation-excited X-ray fluorescence analysis (SR-XRF), particle-induced X-ray emission (PIXE), and X-ray absorption fine structure (XAFS). Typical elements of dental materials were detected in the OLCL, whereas no obvious element accumulation was detected in OLP and negative control specimens. The origin of the detected metallic elements was presumed to be dental alloys through erosion. Therefore, our findings support the feasibility of providing supporting information to distinguish OLCL from OLP by using elemental analysis. PMID:26085368

H+, O2+, O3+ and high resolution PIXE spectra of Yb2O3

NASA Astrophysics Data System (ADS)

Chaves, P. C.; Reis, M. A.

2017-11-01

The number of X-ray spectrometry systems having energy resolution of the order of 10 eV, or less, has increasing recently, included already energy dispersive systems (EDS). Access to previous unseen spectra details and enhanced information including speciation, becomes more common and available. Analysis of high resolution EDS PIXE spectra is, nevertheless a complex task due to the need to carefully account for contributions from minor and satellite transitions. In this work, a pure Yb2O3 sample was irradiated at the HRHE-PIXE setup of C2TN, and simultaneous CdTe and X-ray Microcalorimeter Spectrometer (XMS) spectra were collected. The L-shell spectrum of Yb emitted during irradiations using H+ , O2+ and O3+ ions in the energy range from 1.0 to 6.5 MeV was studied. Measured L X-ray spectra were analysed taking into account the effects of the multiple ionization in the L and M shells. All spectra were analysed using the DT2 code, which allows to include in the fitting model diagram lines as well as multi-ionization satellites and any other contributions. In this communication we present the results and discuss details and problems related to the transition energies, intensity, line width data, and multiple ionization satellites.

Micro-PIXE mapping of mineral distribution in mature grain of two pearl millet cultivars

NASA Astrophysics Data System (ADS)

Minnis-Ndimba, R.; Kruger, J.; Taylor, J. R. N.; Mtshali, C.; Pineda-Vargas, C. A.

2015-11-01

Micro-proton-induced X-ray emission (micro-PIXE) was used to map the distribution of several nutritionally important minerals found in the grain tissue of two cultivars of pearl millet (Pennisetum glaucum (L.) R. Br.). The distribution maps revealed that the predominant localisation of minerals was within the germ (consisting of the scutellum and embryo) and the outer grain layers (specifically the pericarp and aleurone); whilst the bulk of the endosperm tissue featured relatively low concentrations of the surveyed minerals. Within the germ, the scutellum was revealed as a major storage tissue for P and K, whilst Ca, Mn and Zn were more prominent within the embryo. Fe was revealed to have a distinctive distribution pattern, confined to the dorsal end of the scutellum; but was also highly concentrated in the outer grain layers. Interestingly, the hilar region was also revealed as a site of high accumulation of minerals, particularly for S, Ca, Mn, Fe and Zn, which may be part of a defensive strategy against infection or damage. Differences between the two cultivars, in terms of the bulk Fe and P content obtained via inductively coupled plasma optical emission spectrometry (ICP-OES), concurred with the average concentration data determined from the analysis of micro-PIXE spectra specifically extracted from the endosperm tissue.

Photoacoustic microbeam-oscillator with tunable resonance direction and amplitude

NASA Astrophysics Data System (ADS)

Wu, Qingjun; Li, Fanghao; Wang, Bo; Yi, Futing; Jiang, J. Z.; Zhang, Dongxian

2018-01-01

We successfully design one photoacoustic microbeam-oscillator actuated by nanosecond laser, which exhibits tunable resonance direction and amplitude. The mechanism of laser induced oscillation is systematically analyzed. Both simulation and experimental results reveal that the laser induced acoustic wave propagates in a multi-reflected mode, resulting in resonance in the oscillator. This newly-fabricated micrometer-sized beam-oscillator has an excellent actuation function, i.e., by tuning the laser frequency, the direction and amplitude of actuation can be efficiently altered, which will have potential industrial applications.

Test results of a resonant integrated microbeam sensor (RIMS) for acoustic emission monitoring

NASA Astrophysics Data System (ADS)

Schoess, Jeffrey N.; Zook, J. David

1998-07-01

An acoustic emission (AE) sensor has been developed by Honeywell Technology Center for avionics, industrial control, and military applications. The AE sensor design is based on an integrated silicon microstructure, a resonant microbeam with micron-level feature size, and frequency sensitivity up to 500 kHz. The AE sensor has been demonstrated successfully in the laboratory test environment to sense and characterize a simulated AE even for structural fatigue crack monitoring applications. The technical design approach and laboratory test results are presented.

Heavy Ion Current Transients in SiGe HBTs

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Reed, Robert A.; Vizkelethy, Gyorgy; McMorrow, Dale; Ferlet-Cavrois, Veronique; Baggio, Jacques; Paillet, Philipe; Duhanel, Olivier; Phillips, Stanley D.; Sutton, Akil K.;

Optical workstation with concurrent, independent multiphoton imaging and experimental laser microbeam capabilities

PubMed Central

Wokosin, David L.; Squirrell, Jayne M.; Eliceiri, Kevin W.; White, John G.

2008-01-01

Experimental laser microbeam techniques have become established tools for studying living specimens. A steerable, focused laser beam may be used for a variety of experimental manipulations such as laser microsurgery, optical trapping, localized photolysis of caged bioactive probes, and patterned photobleaching. Typically, purpose-designed experimental systems have been constructed for each of these applications. In order to assess the consequences of such experimental optical interventions, long-term, microscopic observation of the specimen is often required. Multiphoton excitation, because of its ability to obtain high-contrast images from deep within a specimen with minimal phototoxic effects, is a preferred technique for in vivo imaging. An optical workstation is described that combines the functionality of an experimental optical microbeam apparatus with a sensitive multiphoton imaging system designed for use with living specimens. Design considerations are discussed and examples of ongoing biological applications are presented. The integrated optical workstation concept offers advantages in terms of flexibility and versatility relative to systems implemented with separate imaging and experimental components. PMID:18607511

Optical workstation with concurrent, independent multiphoton imaging and experimental laser microbeam capabilities

NASA Astrophysics Data System (ADS)

Wokosin, David L.; Squirrell, Jayne M.; Eliceiri, Kevin W.; White, John G.

2003-01-01

Experimental laser microbeam techniques have become established tools for studying living specimens. A steerable, focused laser beam may be used for a variety of experimental manipulations such as laser microsurgery, optical trapping, localized photolysis of caged bioactive probes, and patterned photobleaching. Typically, purpose-designed experimental systems have been constructed for each of these applications. In order to assess the consequences of such experimental optical interventions, long-term, microscopic observation of the specimen is often required. Multiphoton excitation, because of its ability to obtain high-contrast images from deep within a specimen with minimal phototoxic effects, is a preferred technique for in vivo imaging. An optical workstation is described that combines the functionality of an experimental optical microbeam apparatus with a sensitive multiphoton imaging system designed for use with living specimens. Design considerations are discussed and examples of ongoing biological applications are presented. The integrated optical workstation concept offers advantages in terms of flexibility and versatility relative to systems implemented with separate imaging and experimental components.

50 Years of the Radiological Research Accelerator Facility (RARAF)

PubMed Central

Marino, Stephen A.

2017-01-01

The Radiological Research Accelerator Facility (RARAF) is in its 50th year of operation. It was commissioned on April 1, 1967 as a collaboration between the Radiological Research Laboratory (RRL) of Columbia University, and members of the Medical Research Center of Brookhaven National Laboratory (BNL). It was initially funded as a user facility for radiobiology and radiological physics, concentrating on monoenergetic neutrons. Facilities for irradiation with MeV light charged particles were developed in the mid-1970s. In 1980 the facility was relocated to the Nevis Laboratories of Columbia University. RARAF now has seven beam lines, each having a dedicated irradiation facility: monoenergetic neutrons, charged particle track segments, two charged particle microbeams (one electrostatically focused to <1 μm, one magnetically focused), a 4.5 keV soft X-ray microbeam, a neutron microbeam, and a facility that produces a neutron spectrum similar to that of the atomic bomb dropped at Hiroshima. Biology facilities are available on site within close proximity to the irradiation facilities, making the RARAF very user friendly. PMID:28140790

Depth profile by Total IBA in perovskite active layers for solar cells

NASA Astrophysics Data System (ADS)

Barreiros, M. A.; Alves, L. C.; Brites, M. J.; Corregidor, V.

2017-08-01

In recent years the record efficiency of perovskite solar cells (PSCs) has been updated exceeding now 20%. However, it is difficult to make PSCs consistently. Definite correlation has been established between the PSC performance and the perovskite film quality which involves mainly morphology, crystallinity and composition. The manufacturing development of these devices is dependent on the characterisation methodologies, on the availability of suitable and reliable analytical techniques to assess the materials composition and quality and on the relationship of these results with the cell performance. Ion beam analytical (IBA) techniques jointly with a micro-ion beam are powerful tools for materials characterisation and can provide a valuable input for the knowledge of perovskite films. Perovskite films based on CH3NH3PbI3 were prepared (from CH3NH3I and PbI2 precursors) in a planar architecture and in a mesoporous TiO2 scaffold. Proton and helium micro-beams at different energies were used in the analysis of PSC active layers, previously characterised by SEM-FEG (Scanning Electron Microscopy with a field emission gun) and XRD (X-ray diffraction). Self-consistent fit of all the obtained PIXE (Particle Induced X-ray Emission) and RBS (Rutherford Backscattering Spectrometry) spectra through Total IBA approach provided depth profiling of perovskite, its precursors and TiO2 and assess their distribution in the films. PbI2 presence and location on the active layer may hinder the charge transport and highly affect the cell performance. IBA techniques allowed to identify regions of non-uniform surface coverage and homogeneous areas and it was possible to establish the undesired presence of PbI2 and its quantitative depth profile in the planar architecture film. In the mesostructured perovskite film it was verified a non-homogeneous distribution with a decreasing of perovskite concentration down to the thin blocking layer. The good agreement between the best fits obtained in a Total IBA approach and the experimental data granted reliability to depth profile results for the studied perovskite films.

Single cell elemental analysis using nuclear microscopy

NASA Astrophysics Data System (ADS)

Ren, M. Q.; Thong, P. S. P.; Kara, U.; Watt, F.

1999-04-01

The use of Particle Induced X-ray Emission (PIXE), Rutherford Backscattering Spectrometry (RBS) and Scanning Transmission Ion Microscopy (STIM) to provide quantitative elemental analysis of single cells is an area which has high potential, particularly when the trace elements such as Ca, Fe, Zn and Cu can be monitored. We describe the methodology of sample preparation for two cell types, the procedures of cell imaging using STIM, and the quantitative elemental analysis of single cells using RBS and PIXE. Recent work on single cells at the Nuclear Microscopy Research Centre,National University of Singapore has centred around two research areas: (a) Apoptosis (programmed cell death), which has been recently implicated in a wide range of pathological conditions such as cancer, Parkinson's disease etc, and (b) Malaria (infection of red blood cells by the malaria parasite). Firstly we present results on the elemental analysis of human Chang liver cells (ATTCC CCL 13) where vanadium ions were used to trigger apoptosis, and demonstrate that nuclear microscopy has the capability of monitoring vanadium loading within individual cells. Secondly we present the results of elemental changes taking place in individual mouse red blood cells which have been infected with the malaria parasite and treated with the anti-malaria drug Qinghaosu (QHS).

GridPix detectors: Production and beam test results

NASA Astrophysics Data System (ADS)

Koppert, W. J. C.; van Bakel, N.; Bilevych, Y.; Colas, P.; Desch, K.; Fransen, M.; van der Graaf, H.; Hartjes, F.; Hessey, N. P.; Kaminski, J.; Schmitz, J.; Schön, R.; Zappon, F.

2013-12-01

The innovative GridPix detector is a Time Projection Chamber (TPC) that is read out with a Timepix-1 pixel chip. By using wafer post-processing techniques an aluminium grid is placed on top of the chip. When operated, the electric field between the grid and the chip is sufficient to create electron induced avalanches which are detected by the pixels. The time-to-digital converter (TDC) records the drift time enabling the reconstruction of high precision 3D track segments. Recently GridPixes were produced on full wafer scale, to meet the demand for more reliable and cheaper devices in large quantities. In a recent beam test the contribution of both diffusion and time walk to the spatial and angular resolutions of a GridPix detector with a 1.2 mm drift gap are studied in detail. In addition long term tests show that in a significant fraction of the chips the protection layer successfully quenches discharges, preventing harm to the chip.

BetaPIX and GIT1 regulate HGF-induced lamellipodia formation and WAVE2 transport.

PubMed

Morimura, Shigeru; Suzuki, Katsuo; Takahashi, Kazuhide

2009-05-08

Formation of lamellipodia is the first step during cell migration, and involves actin reassembly at the leading edge of migrating cells through the membrane transport of WAVE2. However, the factors that regulate WAVE2 transport to the cell periphery for initiating lamellipodia formation have not been elucidated. We report here that in human breast cancer MDA-MB-231 cells, the hepatocyte growth factor (HGF) induced the association between the constitutive complex of betaPIX and GIT1 with WAVE2, which was concomitant with the induction of lamellipodia formation and WAVE2 transport. Although depletion of betaPIX by RNA interference abrogated the HGF-induced WAVE2 transport and lamellipodia formation, GIT1 depletion caused HGF-independent WAVE2 transport and lamellipodia formation. Collectively, we suggest that betaPIX releases cells from the GIT1-mediated suppression of HGF-independent responses and recruits GIT1 to WAVE2, thereby facilitating HGF-induced WAVE2 transport and lamellipodia formation.

Analysis of elements in lake sediment samples by PIXE spectrometry

NASA Astrophysics Data System (ADS)

Chelarescu, E. D.; Radulescu, C.; Stihi, C.; Bretcan, P.; Tanislav, D.; Dulama, I. D.; Stirbescu, R. M.; Teodorescu, S.; Bucurica, I. A.; Andrei, R.; Morarescu, C.

2017-09-01

This work aims to determine the concentrations of several elements (e.g. Pb, Ni, Zn, Mn, Cr, and Fe) from lake sediments, in order to characterize their origin and evolution. Particle Induced X-ray Emission (PIXE) technique using the 3 MV Tandetron™ particle accelerator from National Institute for R&D in Physics and Nuclear Engineering "Horia Hulubei" (IFIN-HH), Magurele-Bucharest, Romania, was applied. Sediment cores from different salt lakes from Romania (i.e. Amara Lake, Caineni Lake, and Movila Miresii Lake) were collected, in August 2015. The content of Pb, Cr, Mn, Fe, and Ni from sediment samples show similarities with other data presented in literature and international regulation. The Zn was the only element with a higher content in all samples (e.g. maximum 401.7-517.3 mg/kg d.w.).

Evaluation of caries progression in dentin treated by fluoride-containing materials using an in-air micro-PIGE and micro-PIXE measurement system

NASA Astrophysics Data System (ADS)

Yamamoto, H.; Iwami, Y.; Yagi, K.; Hayashi, M.; Komatsu, H.; Okuyama, K.; Matsuda, Y.; Yasuda, K.

2015-04-01

It is well-known that fluorine (F) is involved in the progression of caries. The evaluation of caries progression has conventionally been based on the change in mineral content using transverse microradiography (TMR). The purpose of this study was to evaluate the progression of dentinal caries by the change in calcium (Ca) content using Particle-Induced Gamma-ray Emission/Particle-Induced X-ray Emission (PIGE/PIXE) techniques at the Wakasa Wan Energy Research Center. We also assessed the relationship between caries progression rate and the concentration of F penetration into dentin from dental fluoride-containing materials (FCMs). Dentin sections of six extracted human teeth were prepared to obtain various amounts of F uptake using three types of FCMs. F and Ca distribution of specimens were obtained using PIGE/PIXE techniques. After evaluation, the specimens were immersed in 10 ml of demineralizing solution (pH 4.5) to simulate caries attack. To estimate caries progression rates, the same portions of the specimens were evaluated after caries attack treatment using PIGE/PIXE. A negative correlation between the F uptake in dentin and the rate of caries progression was observed. Therefore, caries progression in dentin was reduced by increasing the amount of F uptake from FCMs. This demonstrates that PIGE/PIXE techniques are valuable for estimating caries progression rates.

Antibody Fab display and selection through fusion to the pIX coat protein of filamentous phage.

PubMed

Tornetta, Mark; Baker, Scott; Whitaker, Brian; Lu, Jin; Chen, Qiang; Pisors, Eileen; Shi, Lei; Luo, Jinquan; Sweet, Raymond; Tsui, Ping

2010-08-31

Fab antibody display on filamentous phage is widely applied to de novo antibody discovery and engineering. Here we describe a phagemid system for the efficient display and affinity selection of Fabs through linkage to the minor coat protein pIX. Display was successful by fusion of either Fd or Lc through a short linker to the amino terminus of pIX and co-expression of the counter Lc or Fd as a secreted, soluble fragment. Assembly of functional Fab was confirmed by demonstration of antigen-specific binding using antibodies of known specificity. Phage displaying a Fab specific for RSV-F protein with Fd linked to pIX showed efficient, antigen-specific enrichment when mixed with phage displaying a different specificity. The functionality of this system for antibody engineering was evaluated in an optimization study. A RSV-F protein specific antibody with an affinity of about 2nM was randomized at 4 positions in light chain CDR1. Three rounds of selection with decreasing antigen concentration yielded Fabs with an affinity improvement up to 70-fold and showed a general correlation between enrichment frequency and affinity. We conclude that the pIX coat protein complements other display systems in filamentous phage as an efficient vehicle for low copy display and selection of Fab proteins. 2010 Elsevier B.V. All rights reserved.

Micro-PIXE study of Ag in digestive glands of a nano-Ag fed arthropod ( Porcellio scaber, Isopoda, Crustacea)

NASA Astrophysics Data System (ADS)

Tkalec, Živa Pipan; Drobne, Damjana; Vogel-Mikuš, Katarina; Pongrac, Paula; Regvar, Marjana; Štrus, Jasna; Pelicon, Primož; Vavpetič, Primož; Grlj, Nataša; Remškar, Maja

2011-10-01

Micro-proton induced X-ray emission (micro-PIXE) method was applied to study the micro-localization of silver (Ag) in digestive glands of a terrestrial arthropod (Porcellio scaber) after feeding on silver nanoparticles (nano-Ag) dosed food. The aim of our work was to assess whether feeding on nano-Ag results in the assimilation of silver (Ag) in digestive gland cells. To study micro-localization and elemental distribution of Ag, the animals were fed on food dosed with nanoparticles for 14 days under controlled laboratory conditions. At the end of the feeding exposure, the animals were dissected and digestive glands prepared for micro-PIXE analyses and TEM investigation. The results obtained by micro-PIXE documented high amounts of Ag inside S-cells of the digestive gland epithelium; however, TEM investigation did not show particle aggregates inside digestive gland cells. Also no adverse effect on feeding behavior was recorded what is a measure of toxic effects. We explain the presence of Ag inside the cells as a result of the assimilation of dissoluted Ag ions from ingested nano-Ag particles. Assimilation of excessive amounts of ingested metal ions in S-cells is a well known metal detoxification mechanism in isopods. We discuss the advantages of using micro-PIXE for the micro-localization of elements in biological tissue in studies of interactions between nanoparticles and biological systems.

In situ Biological Dose Mapping Estimates the Radiation Burden Delivered to ‘Spared’ Tissue between Synchrotron X-Ray Microbeam Radiotherapy Tracks

PubMed Central

Rothkamm, Kai; Crosbie, Jeffrey C.; Daley, Frances; Bourne, Sarah; Barber, Paul R.; Vojnovic, Borivoj; Cann, Leonie; Rogers, Peter A. W.

2012-01-01

Microbeam radiation therapy (MRT) using high doses of synchrotron X-rays can destroy tumours in animal models whilst causing little damage to normal tissues. Determining the spatial distribution of radiation doses delivered during MRT at a microscopic scale is a major challenge. Film and semiconductor dosimetry as well as Monte Carlo methods struggle to provide accurate estimates of dose profiles and peak-to-valley dose ratios at the position of the targeted and traversed tissues whose biological responses determine treatment outcome. The purpose of this study was to utilise γ-H2AX immunostaining as a biodosimetric tool that enables in situ biological dose mapping within an irradiated tissue to provide direct biological evidence for the scale of the radiation burden to ‘spared’ tissue regions between MRT tracks. Γ-H2AX analysis allowed microbeams to be traced and DNA damage foci to be quantified in valleys between beams following MRT treatment of fibroblast cultures and murine skin where foci yields per unit dose were approximately five-fold lower than in fibroblast cultures. Foci levels in cells located in valleys were compared with calibration curves using known broadbeam synchrotron X-ray doses to generate spatial dose profiles and calculate peak-to-valley dose ratios of 30–40 for cell cultures and approximately 60 for murine skin, consistent with the range obtained with conventional dosimetry methods. This biological dose mapping approach could find several applications both in optimising MRT or other radiotherapeutic treatments and in estimating localised doses following accidental radiation exposure using skin punch biopsies. PMID:22238667

Hard alpha-keratin degradation inside a tissue under high flux X-ray synchrotron micro-beam: a multi-scale time-resolved study.

PubMed

Leccia, Emilie; Gourrier, Aurélien; Doucet, Jean; Briki, Fatma

2010-04-01

X-rays interact strongly with biological organisms. Synchrotron radiation sources deliver very intense X-ray photon fluxes within micro- or submicro cross-section beams, resulting in doses larger than the MGy. The relevance of synchrotron radiation analyses of biological materials is therefore questionable since such doses, million times higher than the ones used in radiotherapy, can cause huge damages in tissues, with regard to not only DNA, but also proteic and lipid organizations. Very few data concerning the effect of very high X-ray doses in tissues are available in the literature. We present here an analysis of the structural phenomena which occur when the model tissue of human hair is irradiated by a synchrotron X-ray micro-beam. The choice of hair is supported by its hierarchical and partially ordered keratin structure which can be analysed inside the tissue by X-ray diffraction. To assess the damages caused by hard X-ray micro-beams (1 microm(2) cross-section), short exposure time scattering SAXS/WAXS patterns have been recorded at beamline ID13 (ESRF) after various irradiation times. Various modifications of the scattering patterns are observed, they provide fine insight of the radiation damages at various hierarchical levels and also unexpectedly provide information about the stability of the various hierarchical structural levels. It appears that the molecular level, i.e. the alpha helices which are stabilized by hydrogen bonds and the alpha-helical coiled coils which are stabilized by hydrophobic interactions, is more sensitive to radiation than the supramolecular architecture of the keratin filament and the filament packing within the keratin associated proteins matrix, which is stabilized by disulphide bonds. (c) 2009 Elsevier Inc. All rights reserved.

Quantitative analysis of biomedical samples using synchrotron radiation microbeams

NASA Astrophysics Data System (ADS)

Ektessabi, Ali; Shikine, Shunsuke; Yoshida, Sohei

2001-07-01

X-ray fluorescence (XRF) using a synchrotron radiation (SR) microbeam was applied to investigate distributions and concentrations of elements in single neurons of patients with neurodegenerative diseases. In this paper we introduce a computer code that has been developed to quantify the trace elements and matrix elements at the single cell level. This computer code has been used in studies of several important neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease (PD) and parkinsonism-dementia complex (PDC), as well as in basic biological experiments to determine the elemental changes in cells due to incorporation of foreign metal elements. The substantial nigra (SN) tissue obtained from the autopsy specimens of patients with Guamanian parkinsonism-dementia complex (PDC) and control cases were examined. Quantitative XRF analysis showed that neuromelanin granules of Parkinsonian SN contained higher levels of Fe than those of the control. The concentrations were in the ranges of 2300-3100 ppm and 2000-2400 ppm respectively. On the contrary, Zn and Ni in neuromelanin granules of SN tissue from the PDC case were lower than those of the control. Especially Zn was less than 40 ppm in SN tissue from the PDC case while it was 560-810 ppm in the control. These changes are considered to be closely related to the neuro-degeneration and cell death.

14th International Conference on Particle Induced X-ray Emission ("PIXE 2015")

NASA Astrophysics Data System (ADS)

Przybyłowicz, Wojciech Józef; Pineda-Vargas, Carlos

2015-11-01

This special issue of Nuclear Instruments and Methods in Physics Research B contains the proceedings of the 14th International Conference on Particle Induced X-ray Emission ("PIXE 2015") that was held in Somerset West (South Africa) from 25th February to 3rd March 2015.

Computer Graphics: KidPix, the MacIntosh, and Students with Cognitive Disorders.

ERIC Educational Resources Information Center

Olson, Cindy

This teacher's guide provides an overview of KidPix software and contains adaptive applications of the software for Cognitively Disabled-Borderline (CDB) students. Ten lesson plans are given, including: (1) "USing Rubber Stamps/Rubber Stamp Editor"; (2) "Portrait"; (3) "Create a Pattern"; (4) "Garden Mural";…

Presentation Software and the Single Computer.

ERIC Educational Resources Information Center

Brown, Cindy A.

1998-01-01

Shows how the "Kid Pix" software and a single multimedia computer can aid classroom instruction for kindergarten through second grade. Topics include using the computer as a learning center for small groups of students; making a "Kid Pix" slide show; using it as an electronic chalkboard; and creating curriculum-related…

Scanning three-dimensional x-ray diffraction microscopy using a high-energy microbeam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayashi, Y., E-mail: y-hayashi@mosk.tytlabs.co.jp; Hirose, Y.; Seno, Y.

2016-07-27

A scanning three-dimensional X-ray diffraction (3DXRD) microscope apparatus with a high-energy microbeam was installed at the BL33XU Toyota beamline at SPring-8. The size of the 50 keV beam focused using Kirkpatrick-Baez mirrors was 1.3 μm wide and 1.6 μm high in full width at half maximum. The scanning 3DXRD method was tested for a cold-rolled carbon steel sheet sample. A three-dimensional orientation map with 37 {sup 3} voxels was obtained.

Application of PIXE in the determination of the production cross section of a radionuclide decaying by electron capture

NASA Astrophysics Data System (ADS)

Morales, J. R.; Chesta, M. A.; Cancino, S. A.; Miranda, P. A.; Dinator, M. I.; Avila, M. J.

2005-01-01

Proton induced X-ray emission (PIXE) has been applied to the measurement of the production cross section of a radionuclide decaying by electron capture. By performing a PIXE type experiment on the daughter nuclide important advantages are obtained. The determination of some factors with usually large uncertainties, like solid angle and detector efficiency were avoided. The method was applied to the determination of cross section of the reaction 63Cu(d, p)64Cu at 2.4 MeV for 64Cu production. This result is in full agreement with that obtained through the decay of the 1346 keV gamma ray of 64Cu.

Trace-element measurements in atmospheric biomonitors—A look at the relative performance of INAA and PIXE on olive-tree bark

NASA Astrophysics Data System (ADS)

Pacheco, Adriano M. G.; Freitas, Maria do Carmo; Reis, Miguel A.

2003-06-01

As part of an ongoing evaluation of its suitability for atmospheric biomonitoring, bark from olive trees ( Olea europaea Linn.) has been collected and searched for trace elements by means of two nuclear-analytical techniques—instrumental neutron activation analysis (INAA) and proton-induced X-ray emission (PIXE). The sampling for the present study was carried out across two separate sections of an established grid for air-quality surveys in mainland Portugal. The dual location comprises 58 collection sites—littoral-north (29 sites) and littoral-centre (29 sites). Both techniques are intrinsically accurate and may be seen to complement each other in the way that, as a whole, they yield 46 elements, with an overlap of 16 elements. Among the latter, this paper focuses on four of them and looks into their joint determination. Descriptive statistics for soil-related Al and Ti, and for sea-related Cl and Br, show results for each element to be fairly comparable. The degree of association between elemental patterns by either technique, as seen through nonparametric tests (Kendall's RK), is outstanding. No statistical evidence (Wilcoxon's T) for relative bias in correlated samples—consistently higher or lower results by one technique—could be found as well. As far as this study goes, INAA and PIXE may be used interchangeably for determining the present elements in olive-tree bark.

Monte Carlo study of the influence of energy spectra, mesh size, high Z element on dose and PVDR based on 1-D and 3-D heterogeneous mouse head phantom for Microbeam Radiation Therapy.

PubMed

Lin, Hui; Jing, Jia; Xu, Liangfeng; Mao, Xiaoli

2017-12-01

To evaluate the influence of energy spectra, mesh sizes, high Z element on dose and PVDR in Microbeam Radiation Therapy (MRT) based on 1-D analogy-mouse-head-model (1-D MHM) and 3-D voxel-mouse-head-phantom (3-D VMHP) by Monte Carlo simulation. A Microbeam-Array-Source-Model was implemented into EGSnrc/DOSXYZnrc. The microbeam size is assumed to be 25μm, 50μm or 75μm in thickness and fixed 1mm in height with 200μmc-t-c. The influence of the energy spectra of ID17@ESRF and BMIT@CLS were investigated. The mesh size was optimized. PVDR in 1-D MHM and 3-D VMHP was compared with the homogeneous water phantom. The arc influence of 3-D VMHP filled with water (3-D VMHWP) was compared with the rectangle phantom. PVDR of the lower BMIT@CLS spectrum is 2.4times that of ID17@ESRF for lower valley dose. The optimized mesh is 5µm for 25µm, and 10µm for 50µm and 75µm microbeams with 200µmc-t-c. A 500μm skull layer could make PVDR difference up to 62.5% for 1-D MHM. However this influence is limited (<5%) for the farther homogeneous media (e.g. 600µm). The peak dose uniformity of 3-D VMHP at the same depth could be up to 8% for 1.85mm×1mm irradiation field, whereas that of 3-D VMHWP is<1%. The high Z element makes the dose uniformity enhance in target. The surface arc could affect the superficial PVDR (from 44% to 21% in 0.2mm depth), whereas this influence is limited for the more depth (<1%). An accurate MRT dose calculation algorithm should include the influence of 3-D heterogeneous media. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

The non-destructive identification of early Chinese porcelain by PIXE

NASA Astrophysics Data System (ADS)

Cheng, H. S.; Zhang, Z. Q.; Zhang, B.; Yang, F. J.

2004-06-01

PIXE is used for the non-destructive differentiation of early precious Chinese blue and white porcelain made in Yuan (AD 1206-1368), Ming (AD 1368-1644) Dynasty in Jingdezhen from imitations. Also, ancient celadon made in Song Dynasty (AD 960-1279) is identified by measuring the trace elements contained in the glazes.

Effects of 1,1-Dimethylpiperidinium Chloride on the Pests and Allelochemicals of Cotton and Pecan.

Treesearch

P. A. Hedin; J. N. Jenkins; J. C. McCarty; J. E. Mulrooney; W. L. Parrott; A. Borazjani; C. H. Graves; T. H. Filer

1984-01-01

The growth regulator, PIX (mepiquat chloride - 1,1-dimethyl-piperdinium chloride), when applied to cotton (Gossypium hirsutum L.) and pecan (Carya illinoensis Koch), caused internode shortening. PIX did not elicit an increase in resistance in cotton to the tobacco budworm (Heliothis virescens (Fab.)], or in pecan...

Design and characterization of the ePix10k: a high dynamic range integrating pixel ASIC for LCLS detectors

NASA Astrophysics Data System (ADS)

Caragiulo, P.; Dragone, A.; Markovic, B.; Herbst, R.; Nishimura, K.; Reese, B.; Herrmann, S.; Hart, P.; Blaj, G.; Segal, J.; Tomada, A.; Hasi, J.; Carini, G.; Kenney, C.; Haller, G.

2015-05-01

ePix10k is a variant of a novel class of integrating pixel ASICs architectures optimized for the processing of signals in second generation LINAC Coherent Light Source (LCLS) X-Ray cameras. The ASIC is optimized for high dynamic range application requiring high spatial resolution and fast frame rates. ePix ASICs are based on a common platform composed of a random access analog matrix of pixel with global shutter, fast parallel column readout, and dedicated sigma-delta analog to digital converters per column. The ePix10k variant has 100um×100um pixels arranged in a 176×192 matrix, a resolution of 140e- r.m.s. and a signal range of 3.5pC (10k photons at 8keV). In its final version it will be able to sustain a frame rate of 2kHz. A first prototype has been fabricated and characterized. Performance in terms of noise, linearity, uniformity, cross-talk, together with preliminary measurements with bump bonded sensors are reported here.

Multielemental analyses of isomorphous Indian garnet gemstones by XRD and external pixe techniques.

PubMed

Venkateswarulu, P; Srinivasa Rao, K; Kasipathi, C; Ramakrishna, Y

2012-12-01

Garnet gemstones were collected from parts of Eastern Ghats geological formations of Andhra Pradesh, India and their gemological studies were carried out. Their study of chemistry is not possible as they represent mixtures of isomorphism nature, and none of the individual specimens indicate independent chemistry. Hence, non-destructive instrumental methodology of external PIXE technique was employed to understand their chemistry and identity. A 3 MeV proton beam was employed to excite the samples. In the present study geochemical characteristics of garnet gemstones were studied by proton induced X-ray emission. Almandine variety of garnet is found to be abundant in the present study by means of their chemical contents. The crystal structure and the lattice parameters were estimated using X-Ray Diffraction studies. The trace and minor elements are estimated using PIXE technique and major compositional elements are confirmed by XRD studies. The technique is found very useful in characterizing the garnet gemstones. The present work, thus establishes usefulness and versatility of the PIXE technique with external beam for research in Geo-scientific methodology. Copyright © 2012 Elsevier Ltd. All rights reserved.

A dual-PIXE tomography setup for reconstruction of Germanium in ICF target

NASA Astrophysics Data System (ADS)

Guo, N.; Lu, H. Y.; Wang, Q.; Meng, J.; Gao, D. Z.; Zhang, Y. J.; Liang, X. X.; Zhang, W.; Li, J.; Ma, X. J.; Shen, H.

2017-08-01

Inertial Confinement Fusion (ICF) is one type of fusion energy research which could initiate nuclear fusion reactions through heating and compressing thermonuclear fuel. Compared to a pure plastic target, Germanium doping into the CH ablator layer by Glow Discharge Polymer (GDP) technique can increase the ablation velocity and the standoff distance between the ablation front and laser-deposition region. During target fabrication process, quantitative doping of Ge should be accurately controlled. Particle Induced X-ray Emission Tomography (PIXE-T) can make not only quantification of the concentration, but also reconstruction of the spatial distribution of doped element. The Si (Li) detector for PIXE tomography technique had a disadvantage of low counting rate. To make up this deficiency, another detector of Si (Li) with the same configuration positioned at the opposite side with the same detective angle 135° have been implemented. Simultaneously acquired elemental maps of Ge obtained using two detectors may be different because of the X-ray absorption along the X-ray exit route in the target. In this paper, the X-ray detection efficiency is drastically improved by this dual-PIXE tomography system.

High resolution X-ray fluorescence imaging for a microbeam radiation therapy treatment planning system

NASA Astrophysics Data System (ADS)

Chtcheprov, Pavel; Inscoe, Christina; Burk, Laurel; Ger, Rachel; Yuan, Hong; Lu, Jianping; Chang, Sha; Zhou, Otto

2014-03-01

Microbeam radiation therapy (MRT) uses an array of high-dose, narrow (~100 μm) beams separated by a fraction of a millimeter to treat various radio-resistant, deep-seated tumors. MRT has been shown to spare normal tissue up to 1000 Gy of entrance dose while still being highly tumoricidal. Current methods of tumor localization for our MRT treatments require MRI and X-ray imaging with subject motion and image registration that contribute to the measurement error. The purpose of this study is to develop a novel form of imaging to quickly and accurately assist in high resolution target positioning for MRT treatments using X-ray fluorescence (XRF). The key to this method is using the microbeam to both treat and image. High Z contrast media is injected into the phantom or blood pool of the subject prior to imaging. Using a collimated spectrum analyzer, the region of interest is scanned through the MRT beam and the fluorescence signal is recorded for each slice. The signal can be processed to show vascular differences in the tissue and isolate tumor regions. Using the radiation therapy source as the imaging source, repositioning and registration errors are eliminated. A phantom study showed that a spatial resolution of a fraction of microbeam width can be achieved by precision translation of the mouse stage. Preliminary results from an animal study showed accurate iodine profusion, confirmed by CT. The proposed image guidance method, using XRF to locate and ablate tumors, can be used as a fast and accurate MRT treatment planning system.

PIXE Analysis of Artificial Turf

NASA Astrophysics Data System (ADS)

Conlan, Skye; Chalise, Sajju; Porat, Zachary; Labrake, Scott; Vineyard, Michael

2017-09-01

In recent years, there has been debate regarding the use of the crumb rubber infill in artificial turf on high school and college campuses due to the potential presence of heavy metals and carcinogenic chemicals. We performed Proton-Induced X-Ray Emission (PIXE) analysis of artificial turf infill and blade samples collected from high school and college campuses around the Capital District of NYS to search for potentially toxic substances. Crumb rubber pellets were made by mixing 1g of rubber infill and 1g of epoxy. The pellets and the turf blades were bombarded with 2.2 MeV proton beams from a 1.1-MV tandem Pelletron accelerator in the Union College Ion-Beam Analysis Laboratory and x-ray energy spectra were collected with an Amptek silicon drift detector. We analyzed the spectra using GUPIX software to determine the elemental concentrations of the samples. The turf infill showed significant levels of Ti, Fe, Co, Ni, Cu, Zn, Br, and Pb. The highest concentration of Br in the crumb rubber was 1500 +/-100 ppm while the highest detectable amount of Pb concentration was 110 +/-20 ppm. The artificial turf blades showed significant levels of Ti, Fe, and Zn with only the yellow blade showing concentrations of V and Bi.

Bio-metals imaging and speciation in cells using proton and synchrotron radiation X-ray microspectroscopy

PubMed Central

Ortega, Richard; Devès, Guillaume; Carmona, Asunción

2009-01-01

The direct detection of biologically relevant metals in single cells and of their speciation is a challenging task that requires sophisticated analytical developments. The aim of this article is to present the recent achievements in the field of cellular chemical element imaging, and direct speciation analysis, using proton and synchrotron radiation X-ray micro- and nano-analysis. The recent improvements in focusing optics for MeV-accelerated particles and keV X-rays allow application to chemical element analysis in subcellular compartments. The imaging and quantification of trace elements in single cells can be obtained using particle-induced X-ray emission (PIXE). The combination of PIXE with backscattering spectrometry and scanning transmission ion microscopy provides a high accuracy in elemental quantification of cellular organelles. On the other hand, synchrotron radiation X-ray fluorescence provides chemical element imaging with less than 100 nm spatial resolution. Moreover, synchrotron radiation offers the unique capability of spatially resolved chemical speciation using micro-X-ray absorption spectroscopy. The potential of these methods in biomedical investigations will be illustrated with examples of application in the fields of cellular toxicology, and pharmacology, bio-metals and metal-based nano-particles. PMID:19605403

Phosphorylation of tyrosine 285 of PAK1 facilitates βPIX/GIT1 binding and adhesion turnover

PubMed Central

Hammer, Alan; Oladimeji, Peter; De Las Casas, Luis E.; Diakonova, Maria

2015-01-01

The p21-activated serine-threonine kinase (PAK1) regulates cell motility and adhesion. We have previously shown that the prolactin (PRL)-activated tyrosine kinase JAK2 phosphorylates PAK1 in vivo and in vitro and identified tyrosines 153, 201, and 285 in PAK1 as sites of JAK2 tyrosyl phosphorylation. Here, we further investigate the role of the tyrosyl phosphorylated PAK1 (pTyr-PAK1) in regulation of cell adhesion. We use human breast cancer T47D cell lines that stably overexpress PAK1 wild type or PAK1 Y3F mutant in which these 3 JAK2 phosphorylation sites were mutated to phenylalanine. We demonstrate that PRL/JAK2-dependent phosphorylation of these tyrosines promotes a motile phenotype in the cells upon adhesion, participates in regulation of cell adhesion on collagen IV, and is required for maximal PAK1 kinase activity. Down-regulation of PAK1 abolishes the effect of PAK1 on cell adhesion. We show that the tyrosyl phosphorylation of PAK1 promotes PAK1 binding to β-PAK1-interacting guanine-nucleotide exchange factor (βPIX) and G protein-coupled receptor kinase-interacting target 1 (GIT1), phosphorylation of paxillin on Ser273, and formation and distribution of adhesion complexes. Using phosphospecific antibodies (Abs) directed to single phosphorylated tyrosines on PAK1, we identified Tyr285 as a site of PRL-dependent phosphorylation of PAK1 by JAK2. Furthermore, using PAK1 Y285F mutant, we provide evidence for a role of pTyr285 in cell adhesion, enhanced βPIX/GIT1 binding, and adhesion turnover. Our immunohistochemistry analysis demonstrates that pTyr285- PAK1 may modulate PAK1 signaling during tumor progression.—Hammer, A., Oladimeji, P., De La Casas, L. E., Diakonova, M. Phosphorylation of tyrosine 285 of PAK1 facilitates bPIX/GIT1 binding and adhesion turnover. PMID:25466889

Regional Stratigraphy from Stereo Imaging near the Hypanis Fan Deposit: Marking the Extent of the Largest Delta on Mars?

NASA Astrophysics Data System (ADS)

Adler, J.; Harrison, T. N.; Bell, J. F., III; Mayer, D. P.

2017-12-01

The layered fan-shaped sedimentary deposit at the terminus of Hypanis Valles has been classified by some as an ancient delta marking the presence of a sea in Chryse Planitia, Mars. The deposit's age is estimated to be 3.6 Ga based on crater counts in the upstream catchment. We further our research on the Hypanis deposit and its relative age by analyzing digital terrain models and high-resolution orbital images of two key study areas: Lederberg crater rim and the distal island deposits. We constructed a 2 m/pix digital terrain model from our requested HiRISE stereo images (0.5 m/pix) of the Lederberg rim northwest of Hypanis, as well as a 24 m/pix digital terrain model from CTX stereo images (6 m/pix) of the island structures northeast of Hypanis. Both terrain models were controlled to MOLA shot data. We added these elevation models to a regional elevation mosaic in order to assess stratigraphy. We found that the Lederberg crater rim has polygonally fractured units, consistent with those in the plains near Hypanis, as well as an example of a distinct mildly sinuous ridge with smooth cones along its profile. We hypothesize that the formation of rounded cones in this region of Xanthe Terra near Hypanis is related to the presence of wrinkle ridges and degraded crater rims. Furthermore, we investigate whether these cones are the youngest geologic formations in the region, postdating the aqueous periods in which the delta and hydrovolcanic cones were formed. We also analyzed the elevation profiles of potential deltaic distal island deposits, and found that some islands are likely part of the main lobe of Hypanis, while others more closely match the chaos units to the east. From our analysis, it is unlikely that the large northern island was once part of the Hypanis deposit. Rather, a larger laterally continuous unit likely once draped the region post-Hypanis formation and has subsequently been eroded.

Standardization of proton-induced x-ray emission technique for analysis of thick samples

NASA Astrophysics Data System (ADS)

Ali, Shad; Zeb, Johar; Ahad, Abdul; Ahmad, Ishfaq; Haneef, M.; Akbar, Jehan

2015-09-01

This paper describes the standardization of the proton-induced x-ray emission (PIXE) technique for finding the elemental composition of thick samples. For the standardization, three different samples of standard reference materials (SRMs) were analyzed using this technique and the data were compared with the already known data of these certified SRMs. These samples were selected in order to cover the maximum range of elements in the periodic table. Each sample was irradiated for three different values of collected beam charges at three different times. A proton beam of 2.57 MeV obtained using 5UDH-II Pelletron accelerator was used for excitation of x-rays from the sample. The acquired experimental data were analyzed using the GUPIXWIN software. The results show that the SRM data and the data obtained using the PIXE technique are in good agreement.

PROTON MICROPROBE ANALYSIS OF TRACE-ELEMENT VARIATIONS IN VITRINITES IN THE SAME AND DIFFERENT COAL BEDS.

USGS Publications Warehouse

Minkin, J.A.; Chao, E.C.T.; Blank, Herma; Dulong, F.T.

1987-01-01

The PIXE (proton-induced X-ray emission) microprobe can be used for nondestructive, in-situ analyses of areas as small as those analyzed by the electron microprobe, and has a sensitivity of detection as much as two orders of magnitude better than the electron microprobe. Preliminary studies demonstrated that PIXE provides a capability for quantitative determination of elemental concentrations in individual coal maceral grains with a detection limit of 1-10 ppm for most elements analyzed. Encouraged by the earlier results, we carried out the analyses reported below to examine trace element variations laterally (over a km range) as well as vertically (cm to m) in the I and J coal beds in the Upper Cretaceous Ferron Sandstone Member of the Mancos Shale in central Utah, and to compare the data with the data from two samples of eastern coals of Pennsylvanian age.

PIXE analysis of tumors and localization behavior of a lanthanide in nude mice

NASA Astrophysics Data System (ADS)

Chang, Pei-Jiun; Yang, Czau-Siung; Chou, Ming-Ji; Wei, Chau-Chin; Hsu, Chu-Chung; Wang, Chia-Yu

1984-04-01

We have used particle induced X-ray emission (PIXE) to analyze the elemental compositions and uptakes of a lanthanide, yttrium in this report, in tumors and normal tissues of nude mice. A small amount of yttrium nitrate was injected into nude mice with tumors. Samples of normal and malignant tissues taken from these mice were bombarded by the 2 MeV proton beam from a 3 MeV Van de Graaff accelerator with a Ge detector system to determine the relative elemental compositions of tissues and the relative concentrations of yttrium taken up by these tissues. We found that the uptakes of yttrium by tumors were at least five times more than those by normal tissues. Substantial differences were often observed between the trace element weight (or concentration) pattern of the cancerous and normal tissues. The present result is compared with human tissues.

PIXE and ICP-MS Analysis of Andrographis Paniculata Medicinal Plant

NASA Astrophysics Data System (ADS)

Chandrasekhar Rao, J.; Naidu, B. G.; Sarita, P.; Srikanth, S.; Naga Raju, G. J.

2017-08-01

The concentrations of elements Li, Be, Al, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Ag, Cd, Ba, Pb and U in Andrographis Paniculata medicinal plant used in the treatment of Diabetes Mellitus were determined by using Particle Induced X-ray Emission (PIXE) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) techniques. This plant was collected from four different geographical locations in Andhra Pradesh, India in order to assess the regional variation of elemental concentrations. Appreciable levels of K, Ca, Cr, Mn, Cu and Zn determined in this plant can be correlated to the antidiabetic property of Andrographis Paniculata since these elements are known to regulate and potentiate insulin action. Presence of toxic elements As, Cd and Pb necessitates the adoption of precautionary measures while prescribing dosage of the herbal medicine prepared from this plant for the treatment diabetes mellitus.

Quantitative elemental analysis of an industrial mineral talc, using accelerator-based analytical technique

NASA Astrophysics Data System (ADS)

Olabanji, S. O.; Ige, A. O.; Mazzoli, C.; Ceccato, D.; Ajayi, E. O. B.; De Poli, M.; Moschini, G.

2005-10-01

Accelerator-based technique of PIXE was employed for the determination of the elemental concentration of an industrial mineral, talc. Talc is a very versatile mineral in industries with several applications. Due to this, there is a need to know its constituents to ensure that the workers are not exposed to health risks. Besides, microscopic tests on some talc samples in Nigeria confirm that they fall within the BP British Pharmacopoeia standard for tablet formation. However, for these samples to become a local source of raw material for pharmaceutical grade talc, the precise elemental compositions should be established which is the focus of this work. Proton beam produced by the 2.5 MV AN 2000 Van de Graaff accelerator at INFN, LNL, Legnaro, Padova, Italy was used for the PIXE measurements. The results which show the concentration of different elements in the talc samples, their health implications and metabolic roles are presented and discussed.

Recent applications of PIXE spectrometry in archaeology II. Characterization of Chinese pottery exported to the Islamic world

NASA Astrophysics Data System (ADS)

Fleming, S. J.; Swann, C. P.

1992-02-01

The early 9th century A.D. trade links between China's Tang dynasty and the Western world, by land along the caravan routes of the Silk Road and by sea via India and the Gulf, encouraged a taste for many kinds of Chinese ceramics among the affluent societies of the Islamic empire. Using PIXE analysis to determine the primary composition and minor element patterns of the clay fabrics of a wide range of pottery recovered from the Islamic city of Siraf (in southern Iran), we have established clear differences between Chinese wares imported to that region and a variety of imitative wares of local origin. Parallels and contrasts are drawn between our data and those obtained by Chinese scholars in recent years for the products of various Tang kiln sites, particularly for a series of distinctive stonewares from Tongguan (Hunan province).

PIXE-PIGE analysis of teeth from children with and without cystic fibrosis

NASA Astrophysics Data System (ADS)

Cua, Florence T.

1990-04-01

Proton-induced X-ray emission (PIXE) and proton-induced gamma emission (PIGE) were used to analyze Ca, Sr, Fe, Zn, Cu and F, Na, P, Mg respectively in teeth of children with and without cystic fibrosis. The accelerators used were the 3 MeV proton Van de Graaff accelerator at the Brookhaven National Laboratory, NY, USA for the first run and the 8 MV FN-tandem Van de Graaff accelerator at the Nuclear Physics Laboratory, Rutgers University, NJ, USA producing a 4 MeV proton beam for the second and third run. Description of the experimental setup, and the data acquisition system are described in the text. A summary of the results on element concentration as a function of types of teeth and correlation studies are in the text and in F.T. Cua, Ph.D. Thesis, Rutgers Univ. (1989).

Long-Term Response and Remission with Pixantrone in Patients with Relapsed or Refractory Aggressive Non-Hodgkin Lymphoma: Post-Hoc Analysis of the Multicenter, Open-Label, Randomized PIX301 Trial.

PubMed

Pettengell, Ruth; Coiffier, Bertrand; Egorov, Anton; Singer, Jack; Sivcheva, Lilia

2018-06-01

Pixantrone is recommended in relapsed and refractory non-Hodgkin lymphoma (NHL) or heavily pretreated NHL patients. Its conditional approval in Europe was based on results from the open-label, randomized, phase 3 PIX301 study, comparing pixantrone monotherapy with physician's choice of treatment in 140 patients with relapsed or refractory aggressive NHL. This post-hoc analysis of the PIX301 study investigated possible correlations between patient characteristics and clinical response in 17 patients (24%) treated with pixantrone who achieved a complete response (CR) or an unconfirmed complete response (CRu) at study end. These patients (10 male and 7 female) had a median age of 61 (range 41-75) years, and the most common diagnoses were diffuse large B-cell lymphoma (n = 10) and transformed indolent lymphoma (n = 4). Most had received two prior lines of therapy (n = 12). There was wide variation in the time from diagnosis to study entry (219-4777 days). Among the 17 patients who achieved a CR/CRu with pixantrone, 6 had stable or progressive disease as a response to their last regimen, 7 had a partial response, and 4 had a CR/CRu. Four patients from the pixantrone group survived without progression for more than 400 days. Prior response to previous therapies did not appear to affect long-term response to pixantrone. These observations suggest that pixantrone monotherapy in patients with multiply relapsed or refractory aggressive NHL who had received at least two prior therapies can be associated with durable responses and long-term remission, and this may be unrelated to the clinical response to the last therapy.

Elemental distribution patterns in the skins of false killer whales (Pseudorca crassidens) from a mass stranding in South Africa, analysed using micro-PIXE

NASA Astrophysics Data System (ADS)

Mouton, M.; Botha, A.; Thornton, M.; Mesjasz-Przybyłowicz, J.; Przybyłowicz, W. J.

2015-11-01

Several studies revealed that anthropogenic activities often cause toxic concentrations of some elements, such as mercury, which bio-accumulate through the marine food chain, impacting negatively on the health of animals in the top trophic levels, such as a variety of marine mammals. Moreover, analysis of cetacean skin has been reported to be a reliable, long-term and mostly non-invasive method to monitor bio-accumulation of chemicals in cetacean populations. Several elements, including trace elements, occur naturally in cetacean skin, although nothing is known about their distribution patterns and little about safe base line concentrations. In May 2009, 42 false killer whales (FKWs) beached and died at Kommetjie in the Western Cape of South Africa. Skin samples of these FKWs were collected and analysed to determine elemental distribution patterns. The concentrations and distribution patterns of the major, as well as detectable trace elements were determined in skin samples from ten randomly selected FKW individuals, using micro-PIXE (particle-induced X-ray emission) analysis. Results revealed differences between the distribution patterns of elements in the skin sections. Fe, for example, was found to be concentrated in the dermal papillae, whereas the highest Zn concentrations occurred in the epidermis and particularly in the epidermal papillae. Since these essential elements mediate factors such as host immunity, from skin integrity to humoral immunity, knowledge of their typical distribution patterns can be of great value in studies of bio-accumulation. This is the first report of micro-PIXE being employed to study elemental distribution in cetacean skin and the resulting elemental distribution maps can serve as reference in future environmental pollution studies.

Detection of actinides and rare earths in natural matrices with the AGLAE new, high sensitivity detection set-up

NASA Astrophysics Data System (ADS)

Zucchiatti, Alessandro; Alonso, Ursula; Lemasson, Quentin; Missana, Tiziana; Moignard, Brice; Pacheco, Claire; Pichon, Laurent; Camarena de la Mora, Sandra

2014-08-01

A series of granite samples (Grimsel and Äspö) enriched by sorption with natU (10-3 M, 10-4 M, 10-5 M in solution) and La (10-3 M, 10-4 M in solution) has been scanned by PIXE over a surface of 1920 × 1920 mm2 together with non-enriched Grimsel and Äspö granites and a glass standard. An assessment of minimum detection limits, MDL's, for several elements has been performed with the use of standard materials. Due to mapping and the high sensitivity of the new AGLAE detection system, U levels around 30 ppm can be detected from the whole PIXE spectrum (one low energy detector and four summed filtered detectors) while U reach grains, inhomogeneously distributed over the surface can be clearly identified through the multi elemental maps and analyzed separately. Even the nominally enriched samples have La levels below the MDL, probably because precipitation of the element (and not adsorption) mostly took place, and precipitates were eliminated after surface cleaning carried out before PIXE analyses. A multi detector system that implies a PIXE detection solid angle much wider than in any other similar set-up (a factor of 2-5); a higher events selectivity, given by the possibility of filtering individually up to 4 PIXE detectors; a double RBS detector, the new Ion Beam Induced Luminescence (IBIL) spectrometry and gamma spectrometry. Full mapping capability in air, assisted by a powerful event by event reconstruction software. These features allow lower Minimum Detection Limits (MDL) which are highly beneficial to the analysis of cultural heritage objects, meaning generally a reduction of irradiation time. Paintings will then be studied without any damage to the pigments that have color change tendencies which is a major drawback of the previous system. Alternatively they could allow an increase in information collected at equal time, particularly considering the detector's fast response and therefore the potential for high beam currents when sample damage can be tolerated.This kind of set-up should be advantageous for the detection of elements that are present in a geological, archaeological or artistic samples to the level of a few tens ppm. This is true in particular for the rare earths which are relevant to the provenance attribution of various classes of cultural heritage objects (clays, glasses, …) and the actinides which are relevant in very specific and highly impacting dating problems and, more generally, critical environmental elements with special reference to the radionuclide mobility in deep geological formations hosting radioactive waste [2]. Geological materials are highly heterogeneous and consequently their retention of contaminants is heterogeneous as well. In this frame, the capabilities of the AGLAE set-up would allow an improved characterization of natural heterogeneous rock, detecting the presence of the elements of interest (actinides and rare earth) at concentration levels of tens of ppm. This provides a better definition of the initial system, avoiding biased interpretation of the retention properties of the material for the analysis of possible contamination. Additionally, if lower detection limits were achieved, new perspectives to evaluate retention of low solubility contaminants in a wider range of geochemical conditions would be opened.A glass standard and a series of reference granite samples (Grimsel and Äspö), either enriched by sorption with natU and La or kept natural, have been scanned by PIXE at the New-AGLAE detection system, to test measurement protocols and assess the MDL's allowed by the five detectors system.

The Importance of Particle Induced X-Ray Emission (PIXE) Analysis and Imaging to the Search for Life on the Ocean Worlds

NASA Technical Reports Server (NTRS)

Blake, D. F.; Sarrazin, P.; Thompson, Kathleen

2017-01-01

The MapX imaging X-ray spectrometer is described and Monte Carlo modeling is used to show the efficacy of 244-Cm radioisotope sources in detecting and quantifying the biogenic elements in ices on Ocean Worlds such as Europa.

Chemistry of Airborne Particulate Matter in the Western Plains of Texas Using PIXE Analysis

USDA-ARS?s Scientific Manuscript database

Aerosol samples on polycarbonate filters were collected daily (for 24 hour periods) over several years in Lubbock, Reese Center, and Big Spring in the Southern High Plains region of western Texas, a region known for frequent dust storms. Twenty-seven filter samples representing a variety of particle...

Heavy metals in the atmosphere coming from a copper smelter in Chile

NASA Astrophysics Data System (ADS)

Romo-Kröger, C. M.; Morales, J. R.; Dinator, M. I.; Llona, F.; Eaton, L. C.

The Chilean mine El Teniente is the world's largest underground copper mine. It operates a giant smelter at Caletones (34° 7' S, 70° 27' W) and we have found it is the major source of air contamination in the region. In August 1991 a special circumstance occurred due to a labor strike, with total cessation of activities. A time series analysis of airborne particles collected at a site about 13 km from the smelter was performed in a period including the strike. The PIXE method and other techniques were used to analyse fine (<2.5 μm) and coarse (2.5-15 μm) particles on Nuclepore filters. S, Cu, Zn and As were quite enriched in normal working periods relative to the strike period. Elemental characterization of soil samples by radioactive source analysis demonstrated that this group of elements did not come from airborne soil dust. Cluster analyses of the interelement correlation matrices, resulting from PIXE data, showed one group (Si, K, Ca, Fe) with main origin in soil and another group (S, Cu, Zn, As) coming from the copper smelter.

Proton Induced X-Ray Emission (PIXE): Determining the Concentration of Samples

NASA Astrophysics Data System (ADS)

McCarthy, Mallory; Rodriguez Manso, Alis; Pajouhafsar, Yasmin; J Yennello, Sherry

2017-09-01

We used Proton Induced X-ray Emission (PIXE) as an analysis technique to determine the composition of samples, in particular, the elemental constituents and the concentrations. Each of the samples are bombarded with protons, which in result displaces a lower level electron and causes a higher level electron to fall into its place. This displacement produces characteristic x-rays that are `fingerprints' for each element. The protons supplied for the bombardment are produced and accelerated by the K150 proton beam in the Cyclotron Institute at Texas A&M University. The products are detected by three x-ray detectors: XR-100CR Si-PIN, XR-100SDD, and XR-100T CdTe. The peaks of the spectrum are analyzed using a software analysis tool, GUPIXWIN, to determine the concentration of the known elements of each particular sample. The goals of this work are to test run the Proton Induced X-Ray Emission experimental set up at Texas A&M University (TAMU) and to determine the concentration of thin films containing KBr given by the TAMU Chemical Engineering Department.

Analysis of Venetian-type glass fragments from the ancient city of Lezha (Albania)

NASA Astrophysics Data System (ADS)

Šmit, Ž.; Stamati, F.; Civici, N.; Vevecka-Priftaj, A.; Kos, M.; Jezeršek, D.

2009-08-01

A series of glasses excavated in the Albanian city of Lezha (ancient Lissos) were analyzed by the combined PIXE-PIGE method in air and by source-excited XRF. The analysis revealed two types of glass that can be identified as façon de Venise glass and its subsequent younger phase, produced by chemically purer components and using As 2O 3 as decolorant.

Ion Beam Facility at the University of Chile; Applications and Basic Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miranda, P. A.; Morales, J. R.; Cancino, S.

2010-08-04

The main characteristics of the ion beam facility based on a 3.75 MeV Van de Graaff accelerator at the University of Chile are described at this work. Current activities are mainly focused on the application of the Ion Beam Analysis techniques for environmental, archaeological, and material science analysis. For instance, Rutherford Backscattering Spectrometry (RBS) is applied to measure thin gold film thickness which are used to determine their resistivity and other electrical properties. At this laboratory the Proton Induced X-Ray Emission (PIXE) and Proton Elastic Scattering Analysis (PESA) methodologies are extensively used for trace element analysis of urban aerosols (Santiago,more » Ciudad de Mexico). A similar study is being carried out at the Antarctica Peninsula. Characterization studies on obsidian and vitreous dacite samples using PIXE has been also perform allowing to match some of these artifacts with geological source sites in Chile.Basic physics research is being carried out by measuring low-energy cross section values for the reactions {sup 63}Cu(d,p){sup 64}Cu and {sup Nat}Zn(p,x){sup 67}Ga. Both radionuclide {sup 64}Cu and {sup 67}Ga are required for applications in medicine. Ongoing stopping power cross section measurements of proton and alphas on Pd, Cu, Bi and Mylar are briefly discussed.« less

Ion Beam Facility at the University of Chile; Applications and Basic Research

NASA Astrophysics Data System (ADS)

Miranda, P. A.; Morales, J. R.; Cancino, S.; Dinator, M. I.; Donoso, N.; Sepúlveda, A.; Ortiz, P.; Rojas, S.

2010-08-01

The main characteristics of the ion beam facility based on a 3.75 MeV Van de Graaff accelerator at the University of Chile are described at this work. Current activities are mainly focused on the application of the Ion Beam Analysis techniques for environmental, archaeological, and material science analysis. For instance, Rutherford Backscattering Spectrometry (RBS) is applied to measure thin gold film thickness which are used to determine their resistivity and other electrical properties. At this laboratory the Proton Induced X-Ray Emission (PIXE) and Proton Elastic Scattering Analysis (PESA) methodologies are extensively used for trace element analysis of urban aerosols (Santiago, Ciudad de Mexico). A similar study is being carried out at the Antarctica Peninsula. Characterization studies on obsidian and vitreous dacite samples using PIXE has been also perform allowing to match some of these artifacts with geological source sites in Chile. Basic physics research is being carried out by measuring low-energy cross section values for the reactions 63Cu(d,p)64Cu and NatZn(p,x)67Ga. Both radionuclide 64Cu and 67Ga are required for applications in medicine. Ongoing stopping power cross section measurements of proton and alphas on Pd, Cu, Bi and Mylar are briefly discussed.

Use of different spectroscopic techniques in the analysis of Roman age wall paintings.

PubMed

Agnoli, Francesca; Calliari, Irene; Mazzocchin, Gian-Antonio

2007-01-01

In this paper the analysis of samples of Roman age wall paintings coming from: Pordenone, Vicenza and Verona is carried out by using three different techniques: energy dispersive x-rays spectroscopy (EDS), x-rays fluorescence (XRF) and proton induced x-rays emission (PIXE). The features of the three spectroscopic techniques in the analysis of samples of archaeological interest are discussed. The studied pigments were: cinnabar, yellow ochre, green earth, Egyptian blue and carbon black.

New micro-beam beamline at SPring-8, targeting at protein micro-crystallography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hirata, Kunio; Ueno, Go; Nisawa, Atsushi

2010-06-23

A new protein micro-crystallography beamline BL32XU at SPring-8 is under construction and scheduled to start operation in 2010. The beamline is designed to provide the stabilized and brilliant micro-beam to collect high-quality data from micro-crystals. The beamline consists of a hybrid in-vacuum undulator, a liquid-nitrogen cooled double crystal monochromator, and K-B focusing mirrors with large magnification factor. Development of data acquisition system and end station consists of high-precision diffractometer, high-efficiency area detector, sample auto-changer etc. are also in progress.

Subnanopore filling during water vapor adsorption on microporous silica thin films as seen by low-energy positron annihilation

NASA Astrophysics Data System (ADS)

Ito, Kenji; Yoshimoto, Shigeru; O'Rourke, Brian E.; Oshima, Nagayasu; Kumagai, Kazuhiro

2018-02-01

Positron annihilation lifetime spectroscopy (PALS) using a low-energy positron microbeam extracted into air was applied to elucidating molecular-level pore structures formed in silicon-oxide-backboned microporous thin films under controlled humidity conditions; as a result, a direct observation of the interstitial spaces in the micropores filled with water molecules was achieved. It was demonstrated that PALS using a microbeam extracted into air in combination with water vapor adsorption is a powerful tool for the in-situ elucidation of both open and closed subnanoscaled pores of functional thin materials under practical conditions.

A comprehensive experimental characterization of the iPIX gamma imager

NASA Astrophysics Data System (ADS)

Amgarou, K.; Paradiso, V.; Patoz, A.; Bonnet, F.; Handley, J.; Couturier, P.; Becker, F.; Menaa, N.

2016-08-01

The results of more than 280 different experiments aimed at exploring the main features and performances of a newly developed gamma imager, called iPIX, are summarized in this paper. iPIX is designed to quickly localize radioactive sources while estimating the ambient dose equivalent rate at the measurement point. It integrates a 1 mm thick CdTe detector directly bump-bonded to a Timepix chip, a tungsten coded-aperture mask, and a mini RGB camera. It also represents a major technological breakthrough in terms of lightness, compactness, usability, response sensitivity, and angular resolution. As an example of its key strengths, an 241Am source with a dose rate of only few nSv/h can be localized in less than one minute.

Structural and Functional Studies of the Protamine 2-Zinc Complex from Syrian Gold Hamster (Mesocricetus Auratus) Spermatids and Sperm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolan, Cheryl E.

The research described in this dissertation consists of four major areas: (1) sequence analysis of protamine 2 from Muroid rodents to identify potential zinc-binding domain(s) of protamine 2; (2) structural studies of the protamine 2-zinc complex from Syrian Gold hamster sperm and spermatids to elucidate the role of zinc during spermiogenesis; (3) structural studies of an unique protamine 2-zinc complex from chinchilla sperm; and (4) Nuclear Magnetic Resonance (NMR) studies of soluble complexes of hairpin oligonucleotides with synthetic arginine-rich peptides or protamine 1 isolated from bull sperm. First, zinc was quantitated in spermatids and sperm by Proton-Induced X-ray Emission (PIXE)more » to determine whether zinc is present in the early stages of spermiogenesis. The PIXE results revealed the zinc content varies proportionately with the amount of protamine 2 in both spermatid and sperm nuclei. An exception was chinchilla sperm containing twice the amount of protamine 2 than zinc. Further analyses by PIXE and X-ray Absorption Spectroscopy (XAS) of zinc bound to protamines isolated from hamster sperm confirmed the majority of the zinc is bound to protamine and identified the zinc ligands of protamine 2 in hamster spermatids and sperm in vivo. These studies established that zinc is bound to the protamine 2 precursor in hamster spermatids and the coordination of zinc by protamine 2 changes during spermiogenesis. Finally, the sequence analysis combined with the XAS results suggest that the zinc-binding domain in protamine 2 resides in the amino-terminus. Similar analyses of chinchilla sperm by XAS were performed to clarify the unusual PIXE results and revealed that chinchilla has an atypical protamine 2-zinc structure. Two protamine 2 molecules coordinate one zinc atom, forming homodimers that facilitate the binding of protamine 2 to DNA and provide an organizational scheme that would accommodate the observed species-specific protamine stoichiometry in mammalian sperm. Based on these results, we propose the binding of zinc to protamine 2 molecules stabilizes a dimerization domain in other mammalian sperm. Future experiments will use the knowledge we gained of the interactions between protamine 1 and DNA from the NMR studies to obtain structural data for the DNA-protamine 2-zinc complex.« less

One Click to the Cosmos: The AstroPix Image Archive

NASA Astrophysics Data System (ADS)

Hurt, Robert L.; Llamas, J.; Squires, G. K.; Brinkworth, C.; X-ray Center, Chandra; ESO/ESA; Science Center, Spitzer; STScI

2013-01-01

Imagine a single website that acts as a portal to the entire wealth of public imagery spanning the world's observatories. This is the goal of the AstroPix project (astropix.ipac.caltech.edu), and you can use it today! Although still in a beta development state, this past year has seen the inclusion of thousands of images spanning some of the most prominent observatories in the world, including Chandra, ESO, Galex, Herschel, Hubble, Spitzer, and WISE, with more on the way. The archive is unique as it is built around the Astronomical Visualization Metadata (AVM) standard, which captures the rich contextual information for each image. This ranges from titles and descriptions, to color representations and observation details, to sky coordinates. AVM enables AstroPix imagery to be used in a variety of unique ways that benefit formal and informal education as well as astronomers and the general public. Visitors to Astropix can search the database using simple free-text queries, or use a structured search (similar to "Smart Playlists" found in iTunes, for example). We are also developing public application programming interfaces (APIs) to allow third party software and websites to access the growing content for a variety of uses (planetarium software, museum kiosks, mobile apps, and creative web interfaces, to name a few). Contributing image assets to AstroPix is as easy as tagging the images with the relevant metadata and including the web links to the images in a simple RSS feed. We will cover some of the latest information about tools to contribute images to AstroPix and ways to use the site.

Investigation of chemical vapour deposition diamond detectors by X-ray micro-beam induced current and X-ray micro-beam induced luminescence techniques

NASA Astrophysics Data System (ADS)

Olivero, P.; Manfredotti, C.; Vittone, E.; Fizzotti, F.; Paolini, C.; Lo Giudice, A.; Barrett, R.; Tucoulou, R.

2004-10-01

Tracking detectors have become an important ingredient in high-energy physics experiments. In order to survive the harsh detection environment of the large hadron collider (LHC), trackers need to have special properties. They must be radiation hard, provide fast collection of charge, be as thin as possible and remove heat from readout electronics. The unique properties of diamond allow it to fulfill these requirements. In this work we present an investigation of the charge transport and luminescence properties of "detector grade" artificial chemical vapour deposition (CVD) diamond devices developed within the CERN RD42 collaboration, performed by means of X-ray micro-beam induced current collection (XBICC) and X-ray micro-beam induced luminescence (XBIL) techniques. XBICC technique allows quantitative estimates of the transport parameters of the material to be evaluated and mapped with micrometric spatial resolution. In particular, the high resolution and sensitivity of the technique has allowed a quantitative study of the inhomogeneity of the charge transport parameter defined as the product of mobility and lifetime for both electron and holes. XBIL represents a technique complementary to ion beam induced luminescence (IBIL), which has already been used by our group, since X-ray energy loss profile in the material is different from that of MeV ions. X-ray induced luminescence maps have been performed simultaneously with induced photocurrent maps, to correlate charge transport and induced luminescence properties of diamond. Simultaneous XBICC and XBIL maps exhibit features of partial complementarity that have been interpreted on the basis of considerations on radiative and non-radiative recombination processes which compete with charge transport efficiency.

Examination of Axonal Injury and Regeneration in Microfluidic Neuronal Culture Using Pulsed Laser Microbeam Dissection

PubMed Central

Hellman, Amy N.; Vahidi, Behrad; Kim, Hyung Joon; Mismar, Wael; Steward, Oswald; Jeon, Noo Li; Venugopalan, Vasan

2010-01-01

We describe the integrated use of pulsed laser microbeams and microfluidic cell culture to examine the dynamics of axonal injury and regeneration in vitro. Microfabrication methods are used to place high purity dissociated central nervous system neurons in specific regions that allow the axons to interact with permissive and inhibitory substrates. Acute injury to neuron bundles is produced via the delivery of single 180 ps duration, λ=532 nm laser pulses. Laser pulse energies of 400 nJ and 800 nJ produce partial and complete transection of the axons, respectively, resulting in elliptical lesions 25 μm and 50 μm in size. The dynamics of the resulting degeneration and regrowth of proximal and distal axonal segments are examined for up to 8 h using time-lapse microscopy. We find the proximal and distal dieback distances from the site of laser microbeam irradiation to be roughly equal for both partial and complete transection of the axons. In addition, distinct growth cones emerge from the proximal neurite segments within 1–2 h post-injury, followed by a uniform front of regenerating axons that originate from the proximal segment and traverse the injury site within 8 h. We also examine the use of EGTA to chelate the extracellular calcium and potentially reduce the severity of the axonal degeneration following injury. While we find the addition of EGTA to reduce the severity of the initial dieback, it also hampers neurite repair and interfere with the formation of neuronal growth cones to traverse the injury site. This integrated use of laser microbeam dissection within a microfluidic cell culture system to produce precise zones of neuronal injury shows potential for high-throughput screening of agents to promote neuronal regeneration. PMID:20532390

Benchmarking and validation of a Geant4-SHADOW Monte Carlo simulation for dose calculations in microbeam radiation therapy.

PubMed

Cornelius, Iwan; Guatelli, Susanna; Fournier, Pauline; Crosbie, Jeffrey C; Sanchez Del Rio, Manuel; Bräuer-Krisch, Elke; Rosenfeld, Anatoly; Lerch, Michael

2014-05-01

Microbeam radiation therapy (MRT) is a synchrotron-based radiotherapy modality that uses high-intensity beams of spatially fractionated radiation to treat tumours. The rapid evolution of MRT towards clinical trials demands accurate treatment planning systems (TPS), as well as independent tools for the verification of TPS calculated dose distributions in order to ensure patient safety and treatment efficacy. Monte Carlo computer simulation represents the most accurate method of dose calculation in patient geometries and is best suited for the purpose of TPS verification. A Monte Carlo model of the ID17 biomedical beamline at the European Synchrotron Radiation Facility has been developed, including recent modifications, using the Geant4 Monte Carlo toolkit interfaced with the SHADOW X-ray optics and ray-tracing libraries. The code was benchmarked by simulating dose profiles in water-equivalent phantoms subject to irradiation by broad-beam (without spatial fractionation) and microbeam (with spatial fractionation) fields, and comparing against those calculated with a previous model of the beamline developed using the PENELOPE code. Validation against additional experimental dose profiles in water-equivalent phantoms subject to broad-beam irradiation was also performed. Good agreement between codes was observed, with the exception of out-of-field doses and toward the field edge for larger field sizes. Microbeam results showed good agreement between both codes and experimental results within uncertainties. Results of the experimental validation showed agreement for different beamline configurations. The asymmetry in the out-of-field dose profiles due to polarization effects was also investigated, yielding important information for the treatment planning process in MRT. This work represents an important step in the development of a Monte Carlo-based independent verification tool for treatment planning in MRT.

A point kernel algorithm for microbeam radiation therapy

NASA Astrophysics Data System (ADS)

Debus, Charlotte; Oelfke, Uwe; Bartzsch, Stefan

2017-11-01

Microbeam radiation therapy (MRT) is a treatment approach in radiation therapy where the treatment field is spatially fractionated into arrays of a few tens of micrometre wide planar beams of unusually high peak doses separated by low dose regions of several hundred micrometre width. In preclinical studies, this treatment approach has proven to spare normal tissue more effectively than conventional radiation therapy, while being equally efficient in tumour control. So far dose calculations in MRT, a prerequisite for future clinical applications are based on Monte Carlo simulations. However, they are computationally expensive, since scoring volumes have to be small. In this article a kernel based dose calculation algorithm is presented that splits the calculation into photon and electron mediated energy transport, and performs the calculation of peak and valley doses in typical MRT treatment fields within a few minutes. Kernels are analytically calculated depending on the energy spectrum and material composition. In various homogeneous materials peak, valley doses and microbeam profiles are calculated and compared to Monte Carlo simulations. For a microbeam exposure of an anthropomorphic head phantom calculated dose values are compared to measurements and Monte Carlo calculations. Except for regions close to material interfaces calculated peak dose values match Monte Carlo results within 4% and valley dose values within 8% deviation. No significant differences are observed between profiles calculated by the kernel algorithm and Monte Carlo simulations. Measurements in the head phantom agree within 4% in the peak and within 10% in the valley region. The presented algorithm is attached to the treatment planning platform VIRTUOS. It was and is used for dose calculations in preclinical and pet-clinical trials at the biomedical beamline ID17 of the European synchrotron radiation facility in Grenoble, France.

Sizes of particles formed during municipal wastewater treatment.

PubMed

Lech, Smoczynski; Marta, Kosobucka; Michal, Smoczynski; Harsha, Ratnaweera; Krystyna, Pieczulis-Smoczynska

2017-02-01

Volumetric diameters Dv and specific surface area SpS of sludge particles formed during chemical coagulation and electrocoagulation of sewage were determined. The obtained aggregate-flocs differed substantially in both Dv and SpS values. The differences in Dv and SpS values of the analyzed particles were interpreted based on theoretical models for expanding aggregates. The most uniform particles were formed under exposure to: (a) optimal and maximal doses of PIX, (b) optimal doses of PAX, (c) maximal doses of the Al electro-coagulant. The lowest PIX dose produced the least uniform particles. Sludge aggregates-particles produced under exposure to minimal doses of PIX and the Al electro-coagulant were characterized by the lowest SpS values. Sludge particles coagulated by PAX and the particles formed at higher doses of PIX and the Al electro-coagulant had higher SpS values. The particles formed at all doses of the applied coagulants and electro-coagulants were generally classified into two size ranges: the main range and the secondary range. Most particles belonged to the main size range. An increase in the percentage of colloidal hydroxide particles in sewage sludge increased SpS.

Quantification of indium in steel using PIXE

NASA Astrophysics Data System (ADS)

Oliver, A.; Miranda, J.; Rickards, J.; Cheang, J. C.

1989-04-01

The quantitative analysis of steel for endodontics tools was carried out using low-energy protons (≤ 700 keV). A computer program for a thick-target analysis which includes enhancement due to secondary fluorescence was used. In this experiment the L-lines of indium are enhanced due to the proximity of other elements' K-lines to the indium absorption edge. The results show that the ionization cross section expression employed to evaluate this magnitude is important.

Scanning proton microprobe applied to analysis of individual aerosol particles from Amazon Basin

NASA Astrophysics Data System (ADS)

Gerab, Fábio; Artaxo, Paulo; Swietlicki, Erik; Pallon, Jan

1998-03-01

The development of the Scanning Proton Microprobe (SPM) offers a new possibility for individual aerosol particle studies. The SPM joins Particle Induced X-ray Emission (PIXE) elemental analysis qualities with micrometric spatial resolution. In this work the Lund University SPM facility was used for elemental characterization of individual aerosol particles emitted to the atmosphere in the Brazilian Amazon Basin, during gold mining activities by the so-called "gold shops".

Werner Brandt legacy to PIXE: Past and present perspectives

NASA Astrophysics Data System (ADS)

Lapicki, Gregory

2014-01-01

Inner-shell ionization cross sections used in Particle-Induced X-ray Elemental (PIXE) analyses are routinely calculated in the ECPSSR [W. Brandt, G. Lapicki, Phys. Rev. A 23 (1981) 1717-1729] theory and/or semiempirical formulas scaled to that theory. Thirty years after the passing of Werner Brandt, with recognition of his seminal contributions to other research on positron physics and stopping power problems, the work and articles that progressed into the ECPSSR theory for inner-shell ionization by protons and heavier ions are recalled as Brandt's past legacy to the PIXE community. Applications of the ECPSSR and its evolution into the ECUSAR [G. Lapicki, Nucl. Instr. Meth. B 189 (2002) 8-20] theory over the last three decades are reviewed with perspectives on Brandt's present legacy.

Knudsen torque on heated micro beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Qi; Liang, Tengfei; Ye, Wenjing

Thermally induced mechanical loading has been shown to have significant effects on micro/nano objects immersed in a gas with a non-uniform temperature field. While the majority of existing studies and related applications focus on forces, we investigate the torque, and thus the rotational motion, produced by such a mechanism. Using the asymptotic analysis in the near continuum regime, the Knudsen torque acting on an asymmetrically located uniformly heated microbeam in a cold enclosure is investigated. The existence of a non-zero net torque is demonstrated. In addition, it has been found that by manipulating the system configuration, the rotational direction ofmore » the torque can be changed. Two types of rotational motion of the microbeam have been identified: the pendulum motion of a rectangular beam, and the unidirectional rotation of a cylindrical beam. A rotational frequency of 4 rpm can be achieved for the cylindrical beam with a diameter of 3μm at Kn = 0.005. Illustrated by the simulations using the direct simulation of Monte Carlo, the Knudsen torque can be much increased in the transition regime, demonstrating the potential of Knudsen torque serving as a rotation engine for micro/nano objects.« less

A Microbeam Small-Angle X-ray Scattering Study on Enamel Crystallites in Subsurface Lesion

NASA Astrophysics Data System (ADS)

Yagi, N.; Ohta, N.; Matsuo, T.; Tanaka, T.; Terada, Y.; Kamasaka, H.; Kometani, T.

2010-10-01

The early caries lesion in bovine tooth enamel was studied by two different X-ray diffraction systems at the SPring-8 third generation synchrotron radiation facility. Both allowed us simultaneous measurement of the small and large angle regions. The beam size was 6μm at BL40XU and 50μm at BL45XU. The small-angle scattering from voids in the hydroxyapatite crystallites and the wide-angle diffraction from the hydroxyapatite crystals were observed simultaneously. At BL40XU an X-ray image intensifier was used for the small-angle and a CMOS flatpanel detector for the large-angle region. At BL45XU, a large-area CCD detector was used to cover both regions. A linear microbeam scan at BL40XU showed a detailed distribution of voids and crystals and made it possible to examine the structural details in the lesion. The two-dimensional scan at BL45XU showed distribution of voids and crystals in a wider region in the enamel. The simultaneous small- and wide-angle measurement with a microbeam is a powerful tool to elucidate the mechanisms of demineralization and remineralization in the early caries lesion.

Establishing the suitability of quantitative optical CT microscopy of PRESAGE® radiochromic dosimeters for the verification of synchrotron microbeam therapy

NASA Astrophysics Data System (ADS)

Doran, Simon J.; Rahman, A. T. Abdul; Bräuer-Krisch, Elke; Brochard, Thierry; Adamovics, John; Nisbet, Andrew; Bradley, David

2013-09-01

Previous research on optical computed tomography (CT) microscopy in the context of the synchrotron microbeam has shown the potential of the technique and demonstrated high quality images, but has left two questions unanswered: (i) are the images suitably quantitative for 3D dosimetry? and (ii) what is the impact on the spatial resolution of the system of the limited depth-of-field of the microscope optics? Cuvette and imaging studies are reported here that address these issues. Two sets of cuvettes containing the radiochromic plastic PRESAGE® were irradiated at the ID17 biomedical beamline of the European Synchrotron Radiation facility over the ranges 0-20 and 0-35 Gy and a third set of cuvettes was irradiated over the range 0-20 Gy using a standard medical linac. In parallel, three cylindrical PRESAGE® samples of diameter 9.7 mm were irradiated with test patterns that allowed the quantitative capabilities of the optical CT microscope to be verified, and independent measurements of the imaging modulation transfer function (MTF) to be made via two different methods. Both spectrophotometric analysis and imaging gave a linear dose response, with gradients ranging from 0.036-0.041 cm-1 Gy-1 in the three sets of cuvettes and 0.037 (optical CT units) Gy-1 for the imaging. High-quality, quantitative imaging results were obtained throughout the 3D volume, as illustrated by depth-dose profiles. These profiles are shown to be monoexponential, and the linear attention coefficient of PRESAGE® for the synchrotron-generated x-ray beam is measured to be (0.185 ± 0.02) cm-1 in excellent agreement with expectations. Low-level (<5%) residual image artefacts are discussed in detail. It was possible to resolve easily slit patterns of width 37 µm (which are smaller than many of the microbeams used on ID-17), but some uncertainty remains as to whether the low values of MTF for the higher spatial frequencies are scanner related or a result of genuine (but non-ideal) dose distributions. We conclude that microscopy images from our scanner do indeed have intensities that are proportional to spectrophotometric optical density and can thus be used as the basis for accurate dosimetry. However, further investigations are necessary before the microscopy images can be used to make the quantitative measures of peak-to-valley ratios for small-diameter microbeams. We suggest various strategies for moving forward and are optimistic about the future potential of this system.

Technology: Computer Applications for Young Users--BumperCar and KidPix

ERIC Educational Resources Information Center

Van Horn, Royal

2004-01-01

There is a lot of software available for young children, but there are not many applications designed especially for them. This situation may be about to change with the release of BumperCar and a new version of KidPix, both of which recently earned awards from MacWorld magazine. In this article, the author describes this new software and how it…

Bioaccumulation characterization of uranium by a novel Streptomyces sporoverrucosus dwc-3.

PubMed

Li, Xiaolong; Ding, Congcong; Liao, Jiali; Du, Liang; Sun, Qun; Yang, Jijun; Yang, Yuanyou; Zhang, Dong; Tang, Jun; Liu, Ning

2016-03-01

The biosorption mechanisms of uranium on an aerobic bacterial strain Streptomyces sporoverrucosus dwc-3, isolated from a potential disposal site for (ultra-)low uraniferous radioactive waste in Southwest China, were evaluated by using transmission electron microscopy (TEM), energy dispersive X-ray (EDX) analysis, Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), proton induced X-ray emission (PIXE) and enhanced proton backscattering spectrometry (EPBS). Approximately 60% of total uranium at an initial concentration of 10mg/L uranium nitrate solution could be absorbed on 100mg S. sporoverrucosus dwc-3 with an adsorption capacity of more than 3.0mg/g (wet weight) after 12hr at room temperature at pH3.0. The dynamic biosorption process of S. sporoverrucosus dwc-3 for uranyl ions was well described by a pseudo second-order model. S. sporoverrucosus dwc-3 could accumulate uranium on cell walls and within the cell, as revealed by SEM and TEM analysis as well as EDX spectra. XPS and FT-IR analysis further suggested that the absorbed uranium was bound to amino, phosphate and carboxyl groups of the cells. Additionally, PIXE and EPBS results confirmed that ion exchange also contributed to the adsorption process of uranium. Copyright © 2015. Published by Elsevier B.V.

Fixation and chemical analysis of single fog and rain droplets

NASA Astrophysics Data System (ADS)

Kasahara, M.; Akashi, S.; Ma, C.-J.; Tohno, S.

Last decade, the importance of global environmental problems has been recognized worldwide. Acid rain is one of the most important global environmental problems as well as the global warming. The grasp of physical and chemical properties of fog and rain droplets is essential to make clear the physical and chemical processes of acid rain and also their effects on forests, materials and ecosystems. We examined the physical and chemical properties of single fog and raindrops by applying fixation technique. The sampling method and treatment procedure to fix the liquid droplets as a solid particle were investigated. Small liquid particles like fog droplet could be easily fixed within few minutes by exposure to cyanoacrylate vapor. The large liquid particles like raindrops were also fixed successively, but some of them were not perfect. Freezing method was applied to fix the large raindrops. Frozen liquid particles existed stably by exposure to cyanoacrylate vapor after freezing. The particle size measurement and the elemental analysis of the fixed particle were performed in individual base using microscope, and SEX-EDX, particle-induced X-ray emission (PIXE) and micro-PIXE analyses, respectively. The concentration in raindrops was dependent upon the droplet size and the elapsed time from the beginning of rainfall.

Evaluation of cryoanalysis as a tool for analyzing elemental distribution in "live" tardigrades using micro-PIXE

NASA Astrophysics Data System (ADS)

Nilsson, E. J. C.; Pallon, J.; Przybylowicz, W. J.; Wang, Y. D.; Jönsson, K. I.

2014-08-01

Although heavy on labor and equipment, thus not often applied, cryoanalysis of frozen hydrated biological specimens can provide information that better reflects the living state of the organism, compared with analysis in the freeze-dried state. In this paper we report a study where the cryoanalysis facility with cryosectioning capabilities at Materials Research Department, iThemba LABS, South Africa was employed to evaluate the usefulness of combining three ion beam analytical methods (μPIXE, RBS and STIM) to analyze a biological target where a better elemental compositional description is needed - the tardigrade. Imaging as well as quantification results are of interest. In a previous study, the element composition and redistribution of elements in the desiccated and active states of two tardigrade species was investigated. This study included analysis of both whole and sectioned tardigrades, and the aim was to analyze each specimen twice; first frozen hydrated and later freeze-dried. The combination of the three analytical techniques proved useful: elements from C to Rb in the tardigrades could be determined and certain differences in distribution of elements between the frozen hydrated and the freeze-dried states were observed. RBS on frozen hydrated specimens provided knowledge of matrix elements.

Characterization of the air pollution in the urban area of Madrid

NASA Astrophysics Data System (ADS)

Climent-Font, Aurelio; Swietlicki, Erik; Revuelta, Antonio

1994-03-01

An attempt is made to characterize for the first time the urban pollution of Madrid using the combination of conventional gas measurements and an ion beam analytical technique (PIXE) for aerosol monitoring. Different sets of samples were collected selecting different seasons of the year; winter and summer 1992, and also different sampling times; 3 h and 24 h. A group of 18 elements in the mass range from Si to Pb could be analyzed. Concentration of gases in the air was recorded for the following: CO, NO x, NO 2, SO 2 and C xH y. Four sources contributing to the air pollution were obtained by means of absolute principal component analysis where automotive transport emerges as the dominating one. The combination of aerosol (PIXE) and gas data as input to a receptor model proved to be fruitful for the understanding of the underlying chemical and physical processes governing the observed pollution levels. This is a preliminary study whose results will supply the trends and strategies for a more thorough characterization.

Micro-PIXE investigation of bean seeds to assist micronutrient biofortification

NASA Astrophysics Data System (ADS)

Cvitanich, Cristina; Przybyłowicz, Wojciech J.; Mesjasz-Przybyłowicz, Jolanta; Blair, Matthew W.; Astudillo, Carolina; Orłowska, Elżbieta; Jurkiewicz, Anna M.; Jensen, Erik Ø.; Stougaard, Jens

2011-10-01

This study compares the distribution and concentrations of micro- and macronutrients in different bean cultivars with the aim of optimizing the biofortification, a sustainable approach towards improving dietary quality. Micro-PIXE was used to reveal the distribution of Fe, Zn, Mn, Ca, P, S in seeds of common beans (Phaseolus vulgaris) and runner beans (Phaseolus coccineus). Average concentrations of elements in different tissues were obtained using ICP-AES. The highest concentrations of Zn in the studied beans were found in the embryonic axis, but an increased concentration of this element was also detected in the provascular bundles of the cotyledons. The first layer of cells surrounding provascular bundles accumulated high concentrations of Fe, while the next cell layer had an increased concentration of Mn. The analysis showed that the provascular bundles and the first cell layers surrounding them could have a significant role in the storage of important seed micronutrients - Zn, Fe, and Mn. This information has important implications for molecular biology studies aimed at seed biofortification.

Spectral structure of a polycapillary lens shaped X-ray beam

NASA Astrophysics Data System (ADS)

Gogolev, A. S.; Filatov, N. A.; Uglov, S. R.; Hampai, D.; Dabagov, S. B.

2018-04-01

Polycapillary X-ray optics is widely used in X-ray analysis techniques to create a small secondary source, for instance, or to deliver X-rays to the point of interest with minimum intensity losses [1]. The main characteristics of the analytical devices on its base are the size and divergence of the focused or translated beam. In this work, we used the photon-counting pixel detector ModuPIX to study the parameters for polycapillary focused X-ray tube radiation as well as the energy and spatial dependences of radiation at the focus. We have characterized the high-speed spectral camera ModuPIX, which is a single Timepix device with a fast parallel readout allowing up to 850 frames per second with 256 × 256 pixels and a 55 μm pitch defined by the frame frequency. By means of the silicon monochromator the energy response function is measured in clustering mode by the energy scan over total X-ray tube spectrum.

Total elemental composition analysis of soil samples using the PIXE technique

NASA Astrophysics Data System (ADS)

Bolormaa, Oyuntsetseg; Baasansuren, Jamsranjav; Kawasaki, Katsunori; Watanabe, Makiko; Hattroi, Toshiyuki

2007-09-01

The determination of major and trace element contents in soils was developed by acid digestion method combined with particle-induced X-ray emission spectrometry (PIXE). The digestion of soils was achieved by using nitric acid (HNO3), hydrochloric acid HCl and hydrogen peroxide (H2O2) with repeated additions. A 20 μL aliquot from the digested samples was evaporated on the Nuclepore Track-Etch Membrane and irradiated by the 2.5 MeV proton beam from the single-end type Van de Graaff accelerator. The accuracy of this methodology was estimated based on series of measurements done for a reference material of soil CRM 023-050. The proposed experimental procedure was shown to have good reproducibility of the experimental results. The corresponding limits of detection (LODs) for Na, Mg, Al, P, S, Cl, K, Cr, Mn, Fe, Ni, Cu, Zn, As, Sr, Mo and Cd were estimated. Other soil characteristics such as total carbon (TC) and nitrogen (TN) content, pH and electrical conductivity (EC) were also measured.

A two-dimensional vibration analysis of piezoelectrically actuated microbeam with nonideal boundary conditions

NASA Astrophysics Data System (ADS)

Rezaei, M. P.; Zamanian, M.

2017-01-01

In this paper, the influences of nonideal boundary conditions (due to flexibility) on the primary resonant behavior of a piezoelectrically actuated microbeam have been studied, for the first time. The structure has been assumed to treat as an Euler-Bernoulli beam, considering the effects of geometric nonlinearity. In this work, the general nonideal supports have been modeled as a the combination of horizontal, vertical and rotational springs, simultaneously. Allocating particular values to the stiffness of these springs provides the mathematical models for the majority of boundary conditions. This consideration leads to use a two-dimensional analysis of the multiple scales method instead of previous works' method (one-dimensional analysis). If one neglects the nonideal effects, then this paper would be an effort to solve the two-dimensional equations of motion without a need of a combination of these equations using the shortening or stretching effect. Letting the nonideal effects equal to zero and comparing their results with the results of previous approaches have been demonstrated the accuracy of the two-dimensional solutions. The results have been identified the unique effects of constraining and stiffening of boundaries in horizontal, vertical and rotational directions. This means that it is inaccurate to suppose the nonideality of supports only in one or two of these directions like as previous works. The findings are of vital importance as a better prediction of the frequency response for the nonideal supports. Furthermore, the main findings of this effort can help to choose appropriate boundary conditions for desired systems.

Optimisation of X-ray emission from a laser plasma source for the realisation of microbeam in sub-keV region.

PubMed

Di Paolo Emilio, M; Festuccia, R; Palladino, L

2015-09-01

In this work, the X-ray emission generated from a plasma produced by focusing Nd-YAG laser beam on the Mylar and Yttrium targets will be characterised. The goal is to reach the best condition that optimises the X-ray conversion efficiency at 500 eV (pre-edge of the Oxigen K-shell), strongly absorbed by carbon-based structures. The characteristics of the microbeam optical system, the software/hardware control and the preliminary measurements of the X-ray fluence will be presented. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Obsidian provenance determination by using the beam stability controlled BSC-XRF and the PIXE-alpha portable spectrometers of the LANDIS laboratory of the LNS-INFN and IBAM-CNR in Catania (Italy)

NASA Astrophysics Data System (ADS)

Pappalardo, L.; Bracchitta, D.; Palio, O.; Pappalardo, G.; Rizzo, F.

2012-04-01

About 1300 obsidian artefacts coming from various archaeological sites of Sicily were analyzed by using the BSC-XRF (Beam Stability Controlled - X-ray Fluorescence) and PIXE-alpha (Particle Induced X-ray Emission, using low energy alpha particles) portable spectrometers developed at the Landis laboratory at the LNS-INF and IBAM-CNR in Catania (Italy). The portable BSC-XRF system allows the non-destructive analysis of the Rb, Sr, Y, Zr and Nb trace concentrations, which are considered to be characteristic of the obsidian samples and consequently are indicative of the provenance quarries. Quantitative data on Rb, Sr, Y, Zr, Nb trace element concentrations where deduced through the use of a method that makes use of a multi parameter linear regression, previously The portable PIXE-alpha spectrometer allows the quantitative determination of the matrix major elements, from Na to Zn. In the present work the two instrumental devices are presented. The data are from: Milena (Cl), Ustica (Pa), Rocchicella (Ct), Poggio dell'Acquila (Ct), San Marco (Ct), Villaggio del Petraro* (Sr) and Licodia Eubea* (Ct). Results on compositional data for trace elements and major elements allowed to identify Lipari and Pantelleria islands as the only two sources of the analysed samples. Analyses carried out on vitreous artefact found in Rocchicella, showed for the first time that the Palagonite was used as row material. *Preliminary data. Topic of conference: Application of XRS in archaeometry Kind of presentation: oral

External beam pixe programs at the University of California, Davis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eldred, R.A.

A PIXE system in which large or delicate samples are excited by a low-current external proton beam is described. This system has been used to analyze historical printed books and manuscripts, as well as a large variety of archeological artifacts. The steps used to protect the sample from unnecessary beam current are examined. A recent thorough study of the first volume of the Gutenberg 42-line Bible is described in some detail.

The Plasma Interaction Experiment (PIX) description and test program. [electrometers

NASA Technical Reports Server (NTRS)

Ignaczak, L. R.; Haley, F. A.; Domino, E. J.; Culp, D. H.; Shaker, F. J.

1978-01-01

The plasma interaction experiment (PIX) is a battery powered preprogrammed auxiliary payload on the LANDSAT-C launch. This experiment is part of a larger program to investigate space plasma interactions with spacecraft surfaces and components. The varying plasma densities encountered during available telemetry coverage periods are deemed sufficient to determine first order interactions between the space plasma environment and the biased experimental surfaces. The specific objectives of the PIX flight experiment are to measure the plasma coupling current and the negative voltage breakdown characteristics of a solar array segment and a gold plated steel disk. Measurements will be made over a range of surface voltages up to plus or minus kilovolt. The orbital environment will provide a range of plasma densities. The experimental surfaces will be voltage biased in a preprogrammed step sequence to optimize the data returned for each plasma region and for the available telemetry coverage.

Integrated bio-photonics to revolutionize health care enabled through PIX4life and PIXAPP

NASA Astrophysics Data System (ADS)

Jans, Hilde; O'Brien, Peter; Artundo, Iñigo; Porcel, Marco A. G.; Hoofman, Romano; Geuzebroek, Douwe; Dumon, Pieter; van der Vliet, Marcel; Witzens, Jeremy; Bourguignon, Eric; Van Dorpe, Pol; Lagae, Liesbet

2018-02-01

Photonics has become critical to life sciences. However, the field is far from benefiting fully from photonics' capabilities. Today, bulky and expensive optical systems dominate biomedical photonics, even though robust optical functionality can be realized cost-effectively on single photonic integrated circuits (PICs). Such chips are commercially available mostly for telecom applications, and at infrared wavelengths. Although proof-of-concept demonstrations for PICs in life sciences, using visible wavelengths are abundant, the gating factor for wider adoption is limited in resource capacity. Two European pilot lines, PIX4life and PIXAPP, were established to facilitate European R and D in biophotonics, by helping European companies and universities bridge the gap between research and industrial development. Through creation of an open-access model, PIX4life aims to lower barriers to entry for prototyping and validating biophotonics concepts for larger scale production. In addition, PIXAPP enables the assembly and packaging of photonic integrated circuits.

Some new results of PIXE study on Chinese ancient porcelain

NASA Astrophysics Data System (ADS)

Cheng, H. S.; Zhang, B.; Zhu, D.; Yang, F. J.; Sun, X. M.; Guo, M. S.

2005-10-01

This paper reports some new results obtained by PIXE on Chinese ancient porcelain. The first results concern the provenance of blue and white porcelain made during the Tang Dynasty (AD618-907), which are the earliest products found in China. The PIXE experimental results show that they were fired in Huangye Kiln, Gongyi, Henan Province. The chemical composition of the body, white glaze and of the cobalt pigment will be reported. This paper also reports the results for early Chinese blue and white porcelain made under the Yuan dynasty (AD1206-1368) in Jingdezhen, Jiangxi Province. Experimental results show that the chemical composition of the cobalt pigment used by officers and popular are similar. These materials were imported from another country. The local asbolite was used as cobalt pigment material since the early Ming Dynasty (AD1368-1644) in Jingdezhen at folk kiln, and it was used at official kiln until the 16th century.

Use of PIXE-PIGE under variable incident angle for ancient glass corrosion measurements

NASA Astrophysics Data System (ADS)

Weber, G.; Strivay, D.; Martinot, L.; Garnir, H. P.

2002-04-01

Although glass is usually considered as a very stable archaeological material, it can undergo severe degradation. Soda-lime glass, the most common glass throughout ancient times, is particularly sensitive to this problem. The glass surface absorbs moisture from its environment and the contact with CO 2 causes Na 2O and NaOH to convert to Na 2CO 3, which is extremely hygroscopic. The subsequent unstable glass layer can be leached out and causes decomposition of the glass. The non-destructive PIGE-PIXE method of investigation allows detection of this phenomenon even if no visible effect appears. The variable incident angle method is able to discern the depth of the degradation. One aim of such studies is the possible dating or at least fake detecting of archaeological materials. Furthermore, even objects of large size can be investigated with the atmospheric PIGE-PIXE set-up. Some examples of measurements on ancient glass are given.

Developments towards the LHCb VELO upgrade

NASA Astrophysics Data System (ADS)

Cid Vidal, Xabier

2016-09-01

The Vertex Locator (VELO) is a silicon strip detector surrounding the interaction region of the LHCb experiment. The upgrade of the VELO is planned to be installed in 2019-2020, and the current detector will be replaced by a hybrid pixel system equipped with electronics capable of reading out at a rate of 40 MHz. The new detector is designed to withstand the radiation dose expected at an integrated luminosity of 50 fb-1. The detector will be composed of silicon pixel sensors, read out by the VeloPix ASIC that is being developed based on the TimePix/MediPix family. The prototype sensors for the VELO upgrade are being irradiated in five different facilities and the post-irradiation performance is being measured with testbeams, and in the lab. These proceedings present the VELO upgrade and briefly discuss the results of the sensor testing campaign.

Fluorine uptake into the human enamel surface from fluoride-containing sealing materials during cariogenic pH cycling

NASA Astrophysics Data System (ADS)

Yasuhiro, Matsuda; Katsushi, Okuyama; Hiroko, Yamamoto; Hisanori, Komatsu; Masashi, Koka; Takahiro, Sato; Naoki, Hashimoto; Saiko, Oki; Chiharu, Kawamoto; Hidehiko, Sano

2015-04-01

To prevent the formation of caries and reduce dentin hypersensitivity, sealing materials, either with or without fluoride, are generally applied on the tooth in clinical practice. Application of fluoride-free sealing materials results in the formation of an acid-resistant layer on the tooth surface. On the other hand, fluoride-containing sealing materials might not only form an acid-resistant layer but could possibly further provide fluoride to enhance remineralization and reduce demineralization. In this study, the demineralization prevention ability and fluorine uptake rate in human enamel of fluoride-containing sealing materials ["MS coats F" (MSF)] and fluoride-free sealing materials ("hybrid coats 2" [HI]) were evaluated using an automatic pH cycling system. Each material was applied to the original tooth surface, the cut surfaces were covered with sticky wax, and the automatic pH-cycling system simulated daily acid changes (pH 6.8-4.5) occurring in the oral cavity for 4 weeks. Caries progression was analyzed using transverse microradiography (TMR) taken pre and post the 4 weeks of pH cycling. The fluorine and calcium distributions in the carious lesion in each specimen were evaluated using the proton-induced gamma emission (PIGE) and proton-induced X-ray (PIXE) techniques, respectively. TMR analysis showed that both MSF and HI had a caries-preventing effect after 4 weeks of pH cycling. PIGE/PIXE analysis demonstrated that only MSF resulted in fluoride uptake in the enamel surface. Therefore, MSF can help to form an acid-resistant layer and provide fluoride to the enamel surface. The presence of fluoride on the enamel surface suggested that MSF could prevent demineralization, even if the acid-resistant layer was removed, in clinical settings. The data obtained using the PIGE and PIXE techniques are useful for understanding the benefits of the use of a fluoride-containing sealing material for preventing caries.

Elemental composition and sources of fine and ultrafine ambient particles in Erfurt, Germany.

PubMed

Cyrys, J; Stölzel, M; Heinrich, J; Kreyling, W G; Menzel, N; Wittmaack, K; Tuch, T; Wichmann, H-Erich

2003-04-15

We present the first results of a source apportionment for the urban aerosol in Erfurt, Germany, for the period 1995-1998. The analysis is based on data of particle number concentrations (0.01-2.5 microm; mean 1.8 x 10(4) cm(-3), continuous), the concentration of the ambient gases SO(2), NO, NO(2) and CO (continuous), particle mass less than 2.5 microm (PM(2.5)) and less than 10 microm (PM(10)) (Harvard Impactor sampling, mean PM(2.5) 26.3 micro/m(3), mean PM(10) 38.2 microg/m(3)) and the size fractionated concentrations of 19 elements (impactor sampling 0.05-1.62 microm, PIXE analysis). We determined: (a) the correlations between (i) the 1- and 24-h average concentrations of the gaseous pollutants and the particle number as well as the particle mass concentration and (ii) between the 24-h elemental concentrations; (b) Crustal Enrichment Factors for the PIXE elements using Si as reference element; and (c) the diurnal pattern of the measured pollutants on weekdays and on weekends. The highly correlated PIXE elements Si, Al, Ti and Ca having low enrichment factors were identified as soil elements. The strong correlation of particle number concentrations with NO, which is considered to be typically emitted by traffic, and the striking similarity of their diurnal variation suggest that a sizable fraction of the particle number concentration is associated with emission from vehicles. Besides NO and particle number concentrations other pollutants such as NO(2), CO as well as the elements Zn and Cu were strongly correlated and appear to reflect motor vehicle traffic. Sulfur could be a tracer for coal combustion, however, it was not correlated with any of the quoted elements. Highly correlated elements V and Ni have similar enrichment factors and are considered as tracers for oil combustion.

Micro-PIXE analysis of silicate reference standards

USGS Publications Warehouse

Czamanske, G.K.; Sisson, T.W.; Campbell, J.L.; Teesdale, W.J.

1993-01-01

The accuracy and precision of the University of Guelph proton microprobe have been evaluated through trace-element analysis of well-characterized silicate glasses and minerals, including BHVO-1 glass, Kakanui augite and hornblende, and ten other natural samples of volcanic glass, amphibole, pyroxene, and garnet. Using the 2.39 wt% Mo in a NIST steel as the standard, excellent precision and agreement between reported and analyzed abundances were obtained for Fe, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, and Nb. -from Authors

Microcrystallography using single-bounce monocapillary optics

PubMed Central

Gillilan, R. E.; Cook, M. J.; Cornaby, S. W.; Bilderback, D. H.

2010-01-01

X-ray microbeams have become increasingly valuable in protein crystallography. A number of synchrotron beamlines worldwide have adapted to handling smaller and more challenging samples by providing a combination of high-precision sample-positioning hardware, special visible-light optics for sample visualization, and small-diameter X-ray beams with low background scatter. Most commonly, X-ray microbeams with diameters ranging from 50 µm to 1 µm are produced by Kirkpatrick and Baez mirrors in combination with defining apertures and scatter guards. A simple alternative based on single-bounce glass monocapillary X-ray optics is presented. The basic capillary design considerations are discussed and a practical and robust implementation that capitalizes on existing beamline hardware is presented. A design for mounting the capillary is presented which eliminates parasitic scattering and reduces deformations of the optic to a degree suitable for use on next-generation X-ray sources. Comparison of diffraction data statistics for microcrystals using microbeam and conventional aperture-collimated beam shows that capillary-focused beam can deliver significant improvement. Statistics also confirm that the annular beam profile produced by the capillary optic does not impact data quality in an observable way. Examples are given of new structures recently solved using this technology. Single-bounce monocapillary optics can offer an attractive alternative for retrofitting existing beamlines for microcrystallography. PMID:20157276

Simulation of heart infarction by laser microbeams and induction of arrhythmias by optical tweezers

NASA Astrophysics Data System (ADS)

Perner, Birgit; Monajembashi, Shamci; Rapp, Alexander; Wollweber, Leo; Greulich, Karl Otto

2004-10-01

Laser microbeam and optical tweezers were used for micromanipulation of a heart tissue model consisting of embryonic chicken cardiomyocytes and bibroblasts. Using the laser microbeam a would was created, i.e. a sort of artificial heart infarction was generated. The first steps of wound repair were observed by live cell imaging. A complete filling of teh would primarily by migrating fibroblasts but not by cardiomyocytes was detected 18 hours after wounding. In another set of experiments erythrocyte mediated force application (EMFA) by optical tweezers was applied for optomechanical manipulatoin of cardiomyocytes and fibroblasts. Here we demonstrate induction of dramatic distrubances of calcium waves in a group of synchronously beating cardiomyocytes by an optomechanical input that results in cellular deformation. Surprisingly, it was found that putatively non-excitable fibroblasts respond to this mechanical stress with calcium oscillations. The results reported here indicate that the induction of artificial heart infarction can provide insights into healing processes after mycardial injury. EMFA is capable to examine effects of myocardial overload and to provide important information about processes triggered by mechanical stress on the level of single or very few cells. As a perspective, the preseneted techniques may be used to study the influence of drugs on wound healing and coordination of beating in the heart.

Positive and negative tropic curvature induced by microbeam irradiation of protonemal tip cells of the moss Ceratodon purpureus.

PubMed

Lamparter, T; Kagawa, T; Brücker, G; Wada, M

2004-01-01

The photoreceptor phytochrome mediates tropic responses in protonemata of the moss Ceratodon purpureus. Under standard conditions the tip cells grow towards unilateral red light, or perpendicular to the electrical vector of polarized light. In this study the response of tip cells to partial irradiation of the apical region was analysed using a microbeam apparatus. The fluence response curve gave an unexpected pattern: whereas a 15-min microbeam with light intensities around 3 micro mol m (-2) s (-1) induced a growth curvature towards the irradiated side, higher light intensities around 100 micro mol m (-2) s (-1) caused a negative response, the cells grew away from the irradiated side. This avoidance response is explained by two effects: the light intensity is high enough to induce photoconversion into the active Pfr form of phytochrome, not only on the irradiated but also on the non-irradiated side by stray light. At the same time, the strong light on the irradiated side acts antagonistically to Pfr. As a result of this inhibition, the growth direction is moved to the light-avoiding side. Such a Pfr-independent mechanism might be important for the phototropic response to distinguish between the light-directed and light-avoiding side under unilateral light.

Investigating contactless high frequency ultrasound microbeam stimulation for determination of invasion potential of breast cancer cells.

PubMed

Hwang, Jae Youn; Lee, Nan Sook; Lee, Changyang; Lam, Kwok Ho; Kim, Hyung Ham; Woo, Jonghye; Lin, Ming-Yi; Kisler, Kassandra; Choi, Hojong; Zhou, Qifa; Chow, Robert H; Shung, K Kirk

2013-10-01

In this article, we investigate the application of contactless high frequency ultrasound microbeam stimulation (HFUMS) for determining the invasion potential of breast cancer cells. In breast cancer patients, the finding of tumor metastasis significantly worsens the clinical prognosis. Thus, early determination of the potential of a tumor for invasion and metastasis would significantly impact decisions about aggressiveness of cancer treatment. Recent work suggests that invasive breast cancer cells (MDA-MB-231), but not weakly invasive breast cancer cells (MCF-7, SKBR3, and BT-474), display a number of neuronal characteristics, including expression of voltage-gated sodium channels. Since sodium channels are often co-expressed with calcium channels, this prompted us to test whether single-cell stimulation by a highly focused ultrasound microbeam would trigger Ca(2+) elevation, especially in highly invasive breast cancer cells. To calibrate the diameter of the microbeam ultrasound produced by a 200-MHz single element LiNbO3 transducer, we focused the beam on a wire target and performed a pulse-echo test. The width of the beam was ∼17 µm, appropriate for single cell stimulation. Membrane-permeant fluorescent Ca(2+) indicators were utilized to monitor Ca(2+) changes in the cells due to HFUMS. The cell response index (CRI), which is a composite parameter reflecting both Ca(2+) elevation and the fraction of responding cells elicited by HFUMS, was much greater in highly invasive breast cancer cells than in the weakly invasive breast cancer cells. The CRI of MDA-MB-231 cells depended on peak-to-peak amplitude of the voltage driving the transducer. These results suggest that HFUMS may serve as a novel tool to determine the invasion potential of breast cancer cells, and with further refinement may offer a rapid test for invasiveness of tumor biopsies in situ. Copyright © 2013 Wiley Periodicals, Inc.

Determination of the active volumes of solid-state photon-beam dosimetry detectors using the PTB proton microbeam.

PubMed

Poppinga, Daniela; Delfs, Bjoern; Meyners, Jutta; Langner, Frank; Giesen, Ulrich; Harder, Dietrich; Poppe, Bjoern; Looe, Hui K

2018-05-04

This study aims at the experimental determination of the diameters and thicknesses of the active volumes of solid-state photon-beam detectors for clinical dosimetry. The 10 MeV proton microbeam of the PTB (Physikalisch-Technische Bundesanstalt, Braunschweig) was used to examine two synthetic diamond detectors, type microDiamond (PTW Freiburg, Germany), and the silicon detectors Diode E (PTW Freiburg, Germany) and Razor Diode (Iba Dosimetry, Germany). The knowledge of the dimensions of their active volumes is essential for their Monte Carlo simulation and their applications in small-field photon-beam dosimetry. The diameter of the active detector volume was determined from the detector current profile recorded by radially scanning the proton microbeam across the detector. The thickness of the active detector volume was determined from the detector's electrical current, the number of protons incident per time interval and their mean stopping power in the active volume. The mean energy of the protons entering this volume was assessed by comparing the measured and the simulated influence of the thickness of a stack of aluminum preabsorber foils on the detector signal. For all detector types investigated, the diameters measured for the active volume closely agreed with the manufacturers' data. For the silicon Diode E detector, the thickness determined for the active volume agreed with the manufacturer's data, while for the microDiamond detectors and the Razor Diode, the thicknesses measured slightly exceeded those stated by the manufacturers. The PTB microbeam facility was used to analyze the diameters and thicknesses of the active volumes of photon dosimetry detectors for the first time. A new method of determining the thickness values with an uncertainty of ±10% was applied. The results appear useful for further consolidating detailed geometrical knowledge of the solid-state detectors investigated, which are used in clinical small-field photon-beam dosimetry. © 2018 American Association of Physicists in Medicine.

Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

NASA Astrophysics Data System (ADS)

Serduc, Raphaël; van de Looij, Yohan; Francony, Gilles; Verdonck, Olivier; van der Sanden, Boudewijn; Laissue, Jean; Farion, Régine; Bräuer-Krisch, Elke; Siegbahn, Erik Albert; Bravin, Alberto; Prezado, Yolanda; Segebarth, Christoph; Rémy, Chantal; Lahrech, Hana

2008-03-01

Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p < 0.05) was observed in the irradiated cortex 1 day after exposure to 312 Gy, (2) a 0.7% increase (p < 0.05) in the CWC was measured in the irradiated hemispheres 1 day after exposure to 1000 Gy. The results demonstrate the presence of a minor and transient cellular edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT. For more information on this article, see medicalphysicsweb.org

Development of a micro-XRF system for biological samples based on proton-induced quasimonochromatic X-rays

NASA Astrophysics Data System (ADS)

Ploykrachang, K.; Hasegawa, J.; Kondo, K.; Fukuda, H.; Oguri, Y.

2014-07-01

We have developed a micro-XRF system based on a proton-induced quasimonochromatic X-ray (QMXR) microbeam for in vivo measurement of biological samples. A 2.5-MeV proton beam impinged normally on a Cu foil target that was slightly thicker than the proton range. The emitted QMXR behind the Cu target was focused with a polycapillary X-ray half lens. For application to analysis of wet or aquatic samples, we prepared a QMXR beam with an incident angle of 45° with respect to the horizontal plane by using a dipole magnet in order to bend the primary proton beam downward by 45°. The focal spot size of the QMXR microbeam on a horizontal sample surface was evaluated to be 250 × 350 μm by a wire scanning method. A microscope camera with a long working distance was installed perpendicular to the sample surface to identify the analyzed position on the sample. The fluorescent radiation from the sample was collected by a Si-PIN photodiode X-ray detector. Using the setup above, we were able to successfully measure the accumulation and distribution of Co in the leaves of a free-floating aquatic plant on a dilute Co solution surface.

Single Event Transient Analysis of an SOI Operational Amplifier for Use in Low-Temperature Martian Exploration

NASA Technical Reports Server (NTRS)

Laird, Jamie S.; Scheik, Leif; Vizkelethy, Gyorgy; Mojarradi, Mohammad M; Chen, Yuan; Miyahira, Tetsuo; Blalock, Benjamin; Greenwell, Robert; Doyle, Barney

2006-01-01

The next generation of Martian rover#s to be launched by JPL are to examine polar regions where temperatures are extremely low and the absence of an earth-like atmosphere results in high levels of cosmic radiation at ground level. Cosmic rays lead to a plethora of radiation effects including Single Event Transients (SET) which can severely degrade microelectronic functionality. As such, a radiation-hardened, temperature compensated CMOS Single-On-Insulator (SOI) Operational Amplifier has been designed for JPL by the University of Tennessee and fabricated by Honeywell using the SOI V process. SOI technology has been shownto be far less sensitive to transient effects than both bulk and epilayer Si. Broad beam heavy-ion tests at the University of Texas A&M using Kr and Xebeams of energy 25MeV/amu were performed to ascertain the duration and severity of the SET for the op-amp configured for a low and high gain application. However, some ambiguity regarding the location of transient formation required the use of a focused MeV ion microbeam. A 36MeV O6(+) microbeam. the Sandia National Laboratory (SNL) was used to image and verify regions of particular concern. This is a viewgraph presentation

Live cell imaging combined with high-energy single-ion microbeam

NASA Astrophysics Data System (ADS)

Guo, Na; Du, Guanghua; Liu, Wenjing; Guo, Jinlong; Wu, Ruqun; Chen, Hao; Wei, Junzhe

2016-03-01

DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in the cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10-3 s-1 and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10-2 s-1.

Studies of physiology and the morphology of the cat LGN following proton irradiation.

PubMed

Reder, C S; Moyers, M F; Lau, D; Kirby, M A

2000-03-15

We have examined the effects of proton irradiation on the histologic and receptive field properties of thalamic relay cells in the cat visual system. The cat lateral geniculate nucleus (LGN) is a large structure with well-defined anatomical boundaries, and well-described afferent, efferent, and receptive field properties. A 1.0-mm proton microbeam was used on the cat LGN to determine short-term (3 months) and long-term (9 months) receptive field effects of irradiation on LGN relay cells. The doses used were 16-, 40-, and 60-gray (Gy). Following irradiation, abnormalities in receptive field organization were found in 40- and 60-Gy short-term animals, and in all of the long-term animals. The abnormalities included "silent" areas of the LGN where a visual response could not be evoked and other regions that had unusually large or small compound receptive fields. Histologic analysis failed to identify cellular necrosis or vascular damage in the irradiated LGN, but revealed a disruption in retinal afferents to areas of the LGN. These results indicate that microbeam proton irradiation can disrupt cellular function in the absence of obvious cellular necrosis. Moreover, the area and extent of this disruption increased with time, having larger affect with longer post-irradiation periods.

Heterogeneous intratumoral distribution of gadolinium nanoparticles within U87 human glioblastoma xenografts unveiled by micro-PIXE imaging.

PubMed

Carmona, Asuncion; Roudeau, Stéphane; L'Homel, Baptiste; Pouzoulet, Frédéric; Bonnet-Boissinot, Sarah; Prezado, Yolanda; Ortega, Richard

2017-04-15

Metallic nanoparticles have great potential in cancer radiotherapy as theranostic drugs since, they serve simultaneously as contrast agents for medical imaging and as radio-therapy sensitizers. As with other anticancer drugs, intratumoral diffusion is one of the main limiting factors for therapeutic efficiency. To date, a few reports have investigated the intratumoral distribution of metallic nanoparticles. The aim of this study was to determine the quantitative distribution of gadolinium (Gd) nanoparticles after direct intratumoral injection within U87 human glioblastoma tumors grafted in mice, using micro-PIXE (Particle Induced X-ray Emission) imaging. AGuIX (Activation and Guiding of Irradiation by X-ray) 3 nm particles composed of a polysiloxane network surrounded by gadolinium chelates were used. PIXE results indicate that the direct injection of Gd nanoparticles in tumors results in their heterogeneous diffusion, probably related to variations in tumor density. All tumor regions contain Gd, but with markedly different concentrations, with a more than 250-fold difference. Also Gd can diffuse to the healthy adjacent tissue. This study highlights the usefulness of mapping the distribution of metallic nanoparticles at the intratumoral level, and proposes PIXE as an imaging modality to probe the quantitative distribution of metallic nanoparticles in tumors from experimental animal models with micrometer resolution. Copyright © 2017 Elsevier Inc. All rights reserved.

A Detailed Analysis of Aerosols Containing Zn, Pb, and Cl from an Industrial Region of Mexico City

NASA Astrophysics Data System (ADS)

Moffet, R. C.; Desyaterik, Y.; Hopkins, R. J.; Tivanski, A. V.; Gilles, M. K.; Shutthanandan, V.; Molina, L. T.; Gonzalez-Abraham, R.; Johnson, K. S.; Mugica, V.; Molina, M. J.; Laskin, A.; Prather, K. A.

2008-12-01

Measurements in the Northern Mexico City Metropolitan Area during the March, 2006 MILAGRO campaign revealed the frequent appearance of particles with a characteristically high content of internally mixed Zn, Pb, Cl, and P. A detailed analysis of the chemical and physical properties of these particles was performed using a complementary combination of aerosol measurement techniques. Single particles were analyzed using Aerosol Time-of-Flight Mass Spectrometry (ATOFMS) and Computer Controlled Scanning Electron Microscopy/Energy Dispersive X-Ray spectroscopy (CCSEM/EDX). Proton Induced X-Ray Emission (PIXE) analysis of bulk aerosol samples provided time-resolved mass concentrations of individual elements. The PIXE measurements indicated that Zn is more strongly correlated with Cl than with any other element and that Zn concentrations are higher than other non-ferrous transition metals. The Zn- and Pb - containing particles have both spherical and non-spherical morphologies. Many metal rich particles had needle-like structures and were found to be composed of ZnO and/or Zn(NO3)2-6H2O as indicated by scanning transmission x-ray microscopy/near edge X-ray absorption spectroscopy (STXM/NEXAFS). The Zn and Pb rich particles were primarily in the submicron size range and internally mixed with elemental carbon. The unique chemical associations most closely match signatures acquired for garbage incineration.

Uptake and cellular distribution, in four plant species, of fluorescently labeled mesoporous silica nanoparticles.

PubMed

Sun, Dequan; Hussain, Hashmath I; Yi, Zhifeng; Siegele, Rainer; Cresswell, Tom; Kong, Lingxue; Cahill, David M

2014-08-01

We report the uptake of MSNs into the roots and their movement to the aerial parts of four plant species and their quantification using fluorescence, TEM and proton-induced x - ray emission (micro - PIXE) elemental analysis. Monodispersed mesoporous silica nanoparticles (MSNs) of optimal size and configuration were synthesized for uptake by plant organs, tissues and cells. These monodispersed nanoparticles have a size of 20 nm with interconnected pores with an approximate diameter of 2.58 nm. There were no negative effects of MSNs on seed germination or when transported to different organs of the four plant species tested in this study. Most importantly, for the first time, a combination of confocal laser scanning microscopy, transmission electron microscopy and proton-induced X-ray emission (micro-PIXE) elemental analysis allowed the location and quantification MSNs in tissues and in cellular and sub-cellular locations. Our results show that MSNs penetrated into the roots via symplastic and apoplastic pathways and then via the conducting tissues of the xylem to the aerial parts of the plants including the stems and leaves. The translocation and widescale distribution of MSNs in plants will enable them to be used as a new delivery means for the transport of different sized biomolecules into plants.

Possible Overlaps Between Blobs, Grism Apertures, and Dithers

NASA Astrophysics Data System (ADS)

Ryan, R. E.; McCullough, P. R.

2017-06-01

We present a investigation into possible overlaps between the known IR blobs with the grism aperture reference positions and the IR dither patterns. Each aperture was designed to place the science target (e.g. a specific star) on a cosmetically clean area of the IR detector. Similarly, the dither patterns were designed to mitigate cosmetic defects by rarely (or ideally never) placing such targets on known defects. Because blobs accumulate with time, the originally defined apertures and dither patterns may no longer accomplish their goals, it is important to reverify these combinations. We find two potential overlaps between the blob, aperture, and dither combinations, but do not recommend any changes to the current suite of aperture references positions and/or dither patterns for two reasons. First, one of the overlaps occurs with a dither/aperture combination that is seldom used for high-value science operations, but rather more common for wide-field surveys/mosaics. Second, the other overlap is 8.7 pix from a blob that has a fiducial radius of 10 pix, which already represents a very conservative distance. We conclude that a similar analysis should be repeated as new blobs occur, to continue to ensure ideal operations for high-value science targets. The purpose of this report is to document the analysis in order to facilitate its repetition in the future.

μPIXE for a μBrain: The vinegar fly's brain, antenna, sensilla hairs and eye ion concentrations

NASA Astrophysics Data System (ADS)

Reinert, Anja; Barapatre, Nirav; Sachse, Silke; Reinert, Tilo

2011-10-01

The vinegar fly Drosophila melanogaster is used as model organism to study a variety of different scientific purposes. Thus, our laboratory studies the olfactory system by neurobiological experiments. These techniques are often disruptive and need to compensate or exchange the body fluid, the lymph, with an artificial Ringer's solution in defined compartments of the fly. The solution mainly contains Na, Cl, K and Ca and is to keep physiological conditions. Therefore, the knowledge about the ion concentrations in the respective Drosophila lymph is required for a correct mixture of the ions. This paper presents the spatially resolved concentrations of P, S, Cl, K, Ca, Fe, Cu and Zn in lyophilised head cryosections of Drosophila by using quantitative μPIXE at the ion beam facility LIPSION in Leipzig. The PIXE maps enable a detailed analysis of particular regions of interest down to a spatial resolution of 0.5 μm. We quantified the ion concentrations especially in the brain, the antenna and its sensilla hairs acting as the olfactory organ of the fly, in the compound eye and in the mouthparts. The averaged element concentrations of these main compartments are (in descending order): P: 90 mM, K: 81 mM, S: 38 mM, Cl: 18 mM, Ca: 4.9 mM, Fe: 1.4 mM, Zn: 1.2 mM, Cu: 0.06 mM. Certain structures or cavities possess a remarkably high concentration of particular elements and might reflect the different functions of the compartments. An example presented in more detail is the composition of the compound eye. Conclusively, our findings on the ion concentrations might be useful for the mixture of the Drosophila Ringer's solution to ensure physiological conditions in experiments.

The use of nuclear muprobe techniques to study the chemistry of lacustrine sediments and particles

NASA Astrophysics Data System (ADS)

Grime, G. W.; Davison, W.

1993-05-01

The Oxford SPM has been used in two novel studies of lake chemistry: (a) The distribution of dissolved iron in sediment pore waters close to the sediment/water interface has been measured using the novel technique of diffusive equilibration in a thin film (DET). In this technique, which has a spatial resolution of < 1 mm, much less than that of competing techniques (1 cm), a thin layer of polyacrylamide gel is inserted into the sediment and after the rapid equilibration with the pore water, the gel is dried and fixed. The distribution of trace elements can then be measured using mubeam PIXE. Preliminary results have shown for the first time a subsurface maximum of Fe consistent with current theories of Fe dynamics. This paper presents some results obtained using the technique and discusses the limits on resolution and sensitivity, (b) Individual suspended lake particles (predominantly iron oxides and sulphides) have been analysed using point mubeam RBS and PIXE. Of particular interest in this study is the oxidation state of iron rich particles, so RBS with a 1 μm beam was used to determine the Fe: O stoichiometry of single particles. The particles were filtered from a depth of 14 m in Esthwaite Water in the English Lake District and handled in anoxic conditions until evacuation in the SPM sample chamber. Two distinct compositions of iron oxide were determined in clusters of about 5 μm diameter. Analysis by PIXE revealed that FeS was uniformly distributed in the particulate material and that it also contained elevated levels of Cu and Zn. This study was the first to demonstrate directly that discrete clusters of iron oxides are present in black particulate material which is commonly considered to comprise iron sulphides.

Multi-technique characterization of gold electroplating on silver substrates for cultural heritage applications

NASA Astrophysics Data System (ADS)

Ortega-Feliu, I.; Ager, F. J.; Roldán, C.; Ferretti, M.; Juanes, D.; Scrivano, S.; Respaldiza, M. A.; Ferrazza, L.; Traver, I.; Grilli, M. L.

2017-09-01

This work presents a detailed study of a series of silver plates gilded via electroplating techniques in which the characteristics of the coating gold layers are investigated as a function of the electroplating variables (voltage, time, anode surface and temperature). Some reference samples were coated by radio frequency sputtering in order to compare gold layer homogeneity and effective density. Surface analysis was performed by means of atomic and nuclear techniques (SEM-EDX, EDXRF, PIXE and RBS) to obtain information about thickness, homogeneity, effective density, profile concentration of the gold layers and Au-Ag diffusion profiles. The gold layer thickness obtained by PIXE and EDXRF is consistent with the thickness obtained by means of RBS depth profiling. Electroplated gold mass thickness increases with electroplating time, anode area and voltage. However, electrodeposited samples present rough interfaces and gold layer effective densities lower than the nominal density of Au (19.3 g/cm3), whereas sputtering produces uniform layers with nominal density. These analyses provide valuable information to historians and curators and can help the restoration process of gold-plated silver objects.

Elemental concentrations in kidney and liver of mice fed with cafeteria or standard diet determined by particle induced X-ray emission

NASA Astrophysics Data System (ADS)

Leffa, Daniela Dimer; dos Santos, Carla Eliete Iochims; Debastiani, Rafaela; Amaral, Livio; Yoneama, Maria Lucia; Dias, Johnny Ferraz; Andrade, Vanessa Moraes

2014-01-01

The importance of trace elements in human health is well known and their main source is daily diet. Nowadays, one of the biggest issues is the presence of these micronutrients in levels much higher than required, leading to potential toxic effects. The aim of this work was to investigate the elemental content in organs of mice fed with cafeteria or standard diet using PIXE. Twelve male Swiss mice were divided into two groups: control group (standard chow) and cafeteria group (high-caloric diet). After 17 weeks, samples of different organs (kidney and liver) were collected and prepared for PIXE analysis. The Fe concentration in kidney and liver was statistically higher in animals that received the cafeteria diet (p < 0.001). The Al and Si kidney contents were significantly higher for cafeteria diet in relation to standard diet (p < 0.05). Moreover, the standard diet showed significant differences for Cl and K (p < 0.05) in comparison to cafeteria diet in kidney, and for P, S and Zn (p < 0.005) in liver.

PIXE analysis of airborne particulate matter from Monterrey, Mexico. A first survey

NASA Astrophysics Data System (ADS)

Aldape, F.; Flores M, J.; Díaz, R. V.; Hernández-Méndez, B.; Montoya Z, J. M.; Blanco, E. E.; Fuentes, A. F.; Torres-Martínez, L. M.

1999-04-01

A first survey of elemental contents in airborne particulate matter from Monterrey, Nuevo León, Mexico, was performed using PIXE. This second largest industrial city is located 715 km north of Mexico City, and counts with a population of nearly three million inhabitants in its conurbation. Air pollution in the place comes from a great variety of industries ranging from iron smelters to furniture manufacturing, as well as from fuel combustion in vehicles and industries. This study presents results of elemental contents in airborne particulate matter in two particle size fractions: PM 2.5 and PM 15. The samples were collected during five weeks on working days, Monday-Friday, from 9 December 1996 to 14 January 1997. Two samples a day were collected, 12 h each, night-time and day-time. These first results show local pollution as typical from a large urban area in conjunction with an active industry. Thirteen elements were consistently detected in most of the samples and some episodes due to both industrial and human activities were identified. A general discussion about the results obtained is presented.

Analysis of metals with luster: Roman brass and silver

NASA Astrophysics Data System (ADS)

Fajfar, H.; Rupnik, Z.; Šmit, Ž.

2015-11-01

Non-destructive PIXE analysis using in-air proton beam was used for the studies of earliest brass coins issued during the 1st century BC by Greek cities in Asia Minor, Romans and Celts, and for the studies of plated low grade silver coins of the 3rd century AD. The analysis determined the levels of zinc and important trace elements, notably selenium, which confirms spread of selenium-marked copper from the east. For plating, combined tinning and silvering was identified by the mapping technique for the mid 3rd century AD, which evolved into mere plating by 270 AD.

Cadmium localization and quantification in the plant Arabidopsis thaliana using micro-PIXE

NASA Astrophysics Data System (ADS)

Ager, F. J.; Ynsa, M. D.; Domínguez-Solís, J. R.; Gotor, C.; Respaldiza, M. A.; Romero, L. C.

2002-04-01

Remediation of metal-contaminated soils and waters poses a challenging problem due to its implications in the environment and the human health. The use of metal-accumulating plants to remove toxic metals, including Cd, from soil and aqueous streams has been proposed as a possible solution to this problem. The process of using plants for environmental restoration is termed phytoremediation. Cd is a particularly favourable target metal for this technology because it is readily transported and accumulated in the shoots of several plant species. This paper investigates the sites of metal localization within Arabidopsis thaliana leaves, when plants are grown in a cadmium-rich environment, by making use of nuclear microscopy techniques. Micro-PIXE, RBS and SEM analyses were performed on the scanning proton microprobe at the CNA in Seville (Spain), showing that cadmium is sequestered within the trichomes on the leaf surface. Additionally, regular PIXE analyses were performed on samples prepared by an acid digestion method in order to assess the metal accumulation of such plants.

A smart-phone application and a companion website for the improvement of the communication skills of children with autism: clinical rationale, technical development and preliminary results.

PubMed

De Leo, Gianluca; Gonzales, Carol H; Battagiri, Padmaja; Leroy, Gondy

2011-08-01

Autism is a complex neurobiological disorder that is part of a group of disorders known as autism spectrum disorders (ASD). Today, one in 150 individuals is diagnosed with autism. Lack of social interaction and problems with communication are the main characteristics displayed by children with ASD. The Picture Exchange Communication System (PECS) is a communication system where children exchange visual symbols as a form of communication. The visual symbols are laminated pictures stored in a binder. We have designed, developed and are currently testing a software application, called PixTalk which works on any Windows Mobile Smart-phone. Teachers and caregivers can access a web site and select from an online library the images to be downloaded on to the Smart-phone. Children can browse and select images to express their intentions, desires, and emotions using PixTalk. Case study results indicate that PixTalk can be used as part of ongoing therapy.

High resolution rare-earth elements analyses of natural apatite and its application in geo-sciences: Combined micro-PIXE, quantitative CL spectroscopy and electron spin resonance analyses

NASA Astrophysics Data System (ADS)

Habermann, D.; Götte, T.; Meijer, J.; Stephan, A.; Richter, D. K.; Niklas, J. R.

2000-03-01

The rare-earth element (REE) distribution in natural apatite is analysed by micro-PIXE, cathodoluminescence (CL) microscopy and spectroscopy and electron spin resonance (ESR) spectroscopy. The micro-PIXE analyses of an apatite crystal from Cerro de Mercado (Mexico) and the summary of 20 analyses of six francolite (conodonts of Triassic age) samples indicate that most of the REEs are enriched in apatite and francolite comparative to average shale standard (NASC). The analyses of fossil francolite revealing the REE-distribution not to be in balance with the REE-distribution of seawater and fish bone debris. Strong inhomogenous lateral REE-distribution in fossil conodont material is shown by CL-mapping and most probably not being a vital effect. Therefore, the resulting REE-signal from fossil francolite is the sum of vital and post-mortem incorporation. The necessary charge compensation for the substitution of divalent Ca by trivalent REE being done by different kind of electron defects and defect ions.

PROCEEDINGS ON SYNCHROTRON RADIATION: Transfer characterization of sulfur from coal-burning emission to plant leaves by PIXE and XANES

NASA Astrophysics Data System (ADS)

Bao, Liang-Man; Zhang, Gui-Lin; Zhang, Yuan-Xim; Li, Yan; Lin, Jun; Liu, Wei; Cao, Qing-Chen; Zhao, Yi-Dong; Ma, Chen-Yan; Han, Yong

2009-11-01

The impact of coal-burning emission on sulfur in camphor leaves was investigated using Proton Induced X-ray Emission (PIXE) and synchrotron radiation technique X-ray Absorption Near-Edge Structure (XANES) spectroscopy. The PIXE results show that the sulfur concentrations in the leaves collected at the polluted site are significantly higher than those in controls. The Sulfur XANES spectra show the presence of organic (disulfides, thiols, thioethers, sulfonates and sulfoxides) and inorganic sulfur (sulfates) in the leaves. The inorganic sulfur in the leaves of camphor tree polluted by coal combustion is 15% more than that of the control site. The results suggest that the long-term coal-burning pollution resulted in an enhanced content of the total sulfur and sulfate in the leaves, and the uptake of sulfur by leaves had exceeded the metabolic requirement of plants and the excess of sulfur was stored as SO2-4. It can monitor the sulfur pollution in atmosphere.

Examination of laser microbeam cell lysis in a PDMS microfluidic channel using time-resolved imaging

PubMed Central

Quinto-Su, Pedro A.; Lai, Hsuan-Hong; Yoon, Helen H.; Sims, Christopher E.; Allbritton, Nancy L.; Venugopalan, Vasan

2008-01-01

We use time-resolved imaging to examine the lysis dynamics of non-adherent BAF-3 cells within a microfluidic channel produced by the delivery of single highly-focused 540 ps duration laser pulses at λ = 532 nm. Time-resolved bright-field images reveal that the delivery of the pulsed laser microbeam results in the formation of a laser-induced plasma followed by shock wave emission and cavitation bubble formation. The confinement offered by the microfluidic channel constrains substantially the cavitation bubble expansion and results in significant deformation of the PDMS channel walls. To examine the cell lysis and dispersal of the cellular contents, we acquire time-resolved fluorescence images of the process in which the cells were loaded with a fluorescent dye. These fluorescence images reveal cell lysis to occur on the nanosecond to microsecond time scale by the plasma formation and cavitation bubble dynamics. Moreover, the time-resolved fluorescence images show that while the cellular contents are dispersed by the expansion of the laser-induced cavitation bubble, the flow associated with the bubble collapse subsequently re-localizes the cellular contents to a small region. This capacity of pulsed laser microbeam irradiation to achieve rapid cell lysis in microfluidic channels with minimal dilution of the cellular contents has important implications for their use in lab-on-a-chip applications. PMID:18305858

Analysis of Greek small coinage from the classic period

NASA Astrophysics Data System (ADS)

Šmit, Ž.; Šemrov, A.

2018-02-01

A series of 25 Greek coins from the 6th to 4th centuries BC was studied by PIXE for their trace element composition, with an aim to discover the origin of their silver ore. The procedure revealed a counterfeited coin, and then concentrated on distinguishing the coins minted from the ore of Laurion on the Attica peninsula and the coins minted from other sources. Linear discriminant analysis based on the impurities and alloying elements of copper, gold, lead and bismuth revealed that discrimination is indeed possible according to a single canonical variable.

EPOS-WP16: A Platform for European Multi-scale Laboratories

NASA Astrophysics Data System (ADS)

Spiers, Chris; Drury, Martyn; Kan-Parker, Mirjam; Lange, Otto; Willingshofer, Ernst; Funiciello, Francesca; Rosenau, Matthias; Scarlato, Piergiorgio; Sagnotti, Leonardo; W16 Participants

2016-04-01

The participant countries in EPOS embody a wide range of world-class laboratory infrastructures ranging from high temperature and pressure experimental facilities, to electron microscopy, micro-beam analysis, analogue modeling and paleomagnetic laboratories. Most data produced by the various laboratory centres and networks are presently available only in limited "final form" in publications. As such many data remain inaccessible and/or poorly preserved. However, the data produced at the participating laboratories are crucial to serving society's need for geo-resources exploration and for protection against geo-hazards. Indeed, to model resource formation and system behaviour during exploitation, we need an understanding from the molecular to the continental scale, based on experimental data. This contribution will describe the work plans that the laboratories community in Europe is making, in the context of EPOS. The main objectives are: - To collect and harmonize available and emerging laboratory data on the properties and processes controlling rock system behaviour at multiple scales, in order to generate products accessible and interoperable through services for supporting research activities. - To co-ordinate the development, integration and trans-national usage of the major solid Earth Science laboratory centres and specialist networks. The length scales encompassed by the infrastructures included range from the nano- and micrometer levels (electron microscopy and micro-beam analysis) to the scale of experiments on centimetre sized samples, and to analogue model experiments simulating the reservoir scale, the basin scale and the plate scale. - To provide products and services supporting research into Geo-resources and Geo-storage, Geo-hazards and Earth System Evolution.

Micromanipulation by laser microbeam and optical tweezers: from plant cells to single molecules.

PubMed

Greulich, K O; Pilarczyk, G; Hoffmann, A; Meyer Zu Hörste, G; Schäfer, B; Uhl, V; Monajembashi, S

2000-06-01

Complete manipulation by laser light allows precise and gentle treatment of plant cells, subcellular structures, and even individual DNA molecules. Recently, affordable lasers have become available for the construction of microbeams as well as for optical tweezers. This may generate new interest in these tools for plant biologists. Early experiments, reviewed in this journal, showed that laser supported microinjection of material into plant cells or tissues circumvents mechanical problems encountered in microinjection by fragile glass capillaries. Plant protoplasts could be fused with each other when under microscopical observation, and it was no major problem to generate a triple or quadruple fusion product. In the present paper we review experiments where membrane material was prepared from root hair tips and microgravity was simulated in algae. As many plant cells are transparent, it is possible to work inside living, intact cells. New experiments show that it is possible to release by optical micromanipulation, with high spatial resolutions, intracellular calcium from caged compounds and to study calcium oscillations. An example for avian cardiac tissue is given, but the technique is also suitable for plant cell research. As a more technical tool, optical tweezers can be used to spatially fix subcellular structures otherwise moving inside a cell and thus make them available for investigation with a confocal microscope even when the time for image formation is extended (for example at low fluorescence emission). A molecular biological example is the handling of chromosomes and isolated individual DNA molecules by laser microtools. For example, chromosomes can be cut along complex trajectories, not only perpendicular to their long axis. Single DNA molecules are cut by the laser microbeam and, after coupling such a molecule to a polystrene microbead, are handled in complex geometries. Here, the individual DNA molecules are made visible with a conventional fluorescence microscope by fluorescent dyes such as SYBRGreen. The cutting of a single DNA molecule by molecules of the restriction endonuclease EcoRI can be observed directly, i.e. a type of single molecule restriction analysis is possible. Finally, mechanical properties of individual DNA molecules can be observed directly.

Phase contrast portal imaging using synchrotron radiation

NASA Astrophysics Data System (ADS)

Umetani, K.; Kondoh, T.

2014-07-01

Microbeam radiation therapy is an experimental form of radiation treatment with great potential to improve the treatment of many types of cancer. We applied a synchrotron radiation phase contrast technique to portal imaging to improve targeting accuracy for microbeam radiation therapy in experiments using small animals. An X-ray imaging detector was installed 6.0 m downstream from an object to produce a high-contrast edge enhancement effect in propagation-based phase contrast imaging. Images of a mouse head sample were obtained using therapeutic white synchrotron radiation with a mean beam energy of 130 keV. Compared to conventional portal images, remarkably clear images of bones surrounding the cerebrum were acquired in an air environment for positioning brain lesions with respect to the skull structure without confusion with overlapping surface structures.

Synchrotron radiation microbeam X-ray diffraction for nondestructive assessments of local structural properties of faceted InGaN/GaN quantum wells

NASA Astrophysics Data System (ADS)

Sakaki, Atsushi; Funato, Mitsuru; Kawamura, Tomoaki; Araki, Jun; Kawakami, Yoichi

2018-03-01

Synchrotron radiation (SR) X-ray diffraction with a sub-µm spatial resolution is used to nondestructively evaluate the local thickness and alloy composition of three-dimensionally faceted InGaN/GaN quantum wells (QWs). The (0001) facet QW on a trapezoidal structure composed of (0001), \\{ 11\\bar{2}2\\} , and \\{ 11\\bar{2}0\\} facets is nonuniform, most likely owing to the migration of adatoms between facets. The thickness and composition markedly vary within a short distance for the \\{ 11\\bar{2}2\\} facet QW of another pyramidal structure. The QW parameters acquired by SR microbeam X-ray diffraction reproduce the local emission property assessed by cathodoluminescence, thereby indicating the high reliability of this method.

Analysis of the fly ash from the processing of wood chips in a pilot-scale downdraft gasifier: Comparison of inorganic constituents determined by PIXE and ICP-AES

Treesearch

Thomas L Eberhardt; Hui Pan

2013-01-01

Gasification of biomass ultimately generates at least one solid byproduct in which the inorganic constituents of the biomass are concentrated. Given the potential for utilization, or issues with disposal, facile methods are needed for determining the compositions of the fly ashes from recently-available gasifier-based bioenergy systems. Proton induced x-ray emission...

Live cell imaging combined with high-energy single-ion microbeam

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guo, Na; Du, Guanghua, E-mail: gh-du@impcas.ac.cn; Liu, Wenjing

DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics to study early and fast cellular response to DNA damage after high linear energy transfer ion radiation. The HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online. The live cell imaging analysis shows that strand-break repair protein XRCC1 was recruited to the ion hit position within 20 s in themore » cells and formed bright foci in the cell nucleus. The fast recruitment of XRCC1 at the ion hits reached a maximum at about 200 s post-irradiation and then was followed by a slower release into the nucleoplasm. The measured dual-exponential kinetics of XRCC1 protein are consistent with the proposed consecutive reaction model, and the measurements obtained that the reaction rate constant of the XRCC1 recruitment to DNA strand break is 1.2 × 10{sup −3} s{sup −1} and the reaction rate constant of the XRCC1 release from the break-XRCC1 complex is 1.2 × 10{sup −2} s{sup −1}.« less

Monte Carlo simulation of a compact microbeam radiotherapy system based on carbon nanotube field emission technology.

PubMed

Schreiber, Eric C; Chang, Sha X

2012-08-01

Microbeam radiation therapy (MRT) is an experimental radiotherapy technique that has shown potent antitumor effects with minimal damage to normal tissue in animal studies. This unique form of radiation is currently only produced in a few large synchrotron accelerator research facilities in the world. To promote widespread translational research on this promising treatment technology we have proposed and are in the initial development stages of a compact MRT system that is based on carbon nanotube field emission x-ray technology. We report on a Monte Carlo based feasibility study of the compact MRT system design. Monte Carlo calculations were performed using EGSnrc-based codes. The proposed small animal research MRT device design includes carbon nanotube cathodes shaped to match the corresponding MRT collimator apertures, a common reflection anode with filter, and a MRT collimator. Each collimator aperture is sized to deliver a beam width ranging from 30 to 200 μm at 18.6 cm source-to-axis distance. Design parameters studied with Monte Carlo include electron energy, cathode design, anode angle, filtration, and collimator design. Calculations were performed for single and multibeam configurations. Increasing the energy from 100 kVp to 160 kVp increased the photon fluence through the collimator by a factor of 1.7. Both energies produced a largely uniform fluence along the long dimension of the microbeam, with 5% decreases in intensity near the edges. The isocentric dose rate for 160 kVp was calculated to be 700 Gy∕min∕A in the center of a 3 cm diameter target. Scatter contributions resulting from collimator size were found to produce only small (<7%) changes in the dose rate for field widths greater than 50 μm. Dose vs depth was weakly dependent on filtration material. The peak-to-valley ratio varied from 10 to 100 as the separation between adjacent microbeams varies from 150 to 1000 μm. Monte Carlo simulations demonstrate that the proposed compact MRT system design is capable of delivering a sufficient dose rate and peak-to-valley ratio for small animal MRT studies.

High-energy transmission Laue micro-beam X-ray diffraction: a probe for intra-granular lattice orientation and elastic strain in thicker samples.

PubMed

Hofmann, Felix; Song, Xu; Abbey, Brian; Jun, Tea-Sung; Korsunsky, Alexander M

2012-05-01

An understanding of the mechanical response of modern engineering alloys to complex loading conditions is essential for the design of load-bearing components in high-performance safety-critical aerospace applications. A detailed knowledge of how material behaviour is modified by fatigue and the ability to predict failure reliably are vital for enhanced component performance. Unlike macroscopic bulk properties (e.g. stiffness, yield stress, etc.) that depend on the average behaviour of many grains, material failure is governed by `weakest link'-type mechanisms. It is strongly dependent on the anisotropic single-crystal elastic-plastic behaviour, local morphology and microstructure, and grain-to-grain interactions. For the development and validation of models that capture these complex phenomena, the ability to probe deformation behaviour at the micro-scale is key. The diffraction of highly penetrating synchrotron X-rays is well suited to this purpose and micro-beam Laue diffraction is a particularly powerful tool that has emerged in recent years. Typically it uses photon energies of 5-25 keV, limiting penetration into the material, so that only thin samples or near-surface regions can be studied. In this paper the development of high-energy transmission Laue (HETL) micro-beam X-ray diffraction is described, extending the micro-beam Laue technique to significantly higher photon energies (50-150 keV). It allows the probing of thicker sample sections, with the potential for grain-level characterization of real engineering components. The new HETL technique is used to study the deformation behaviour of individual grains in a large-grained polycrystalline nickel sample during in situ tensile loading. Refinement of the Laue diffraction patterns yields lattice orientations and qualitative information about elastic strains. After deformation, bands of high lattice misorientation can be identified in the sample. Orientation spread within individual scattering volumes is studied using a pattern-matching approach. The results highlight the inability of a simple Schmid-factor model to capture the behaviour of individual grains and illustrate the need for complementary mechanical modelling.

The development and characterization of a first generation carbon nanotube x-ray based microbeam radiation therapy system

NASA Astrophysics Data System (ADS)

Hadsell, Michael John, Jr.

Microbeam radiation therapy (MRT) is a new type of cancer treatment currently being studied at scattered synchrotron sites throughout the world. It has been shown to be capable of ablating aggressive brain tumors in rats while almost completely sparing the surrounding normal tissue. This promising technique has yet to find its way to the clinic, however, because the radiobiological mechanisms behind its efficacy are still largely unknown. This is partly due to the lack of a compact device that could facilitate more large scale research. The challenges inherent to creating a compact device lie within the structure of MRT, which uses parallel arrays of ultra high-dose, orthovoltage, microplanar beams on the order of 100mum thick and separated by four to ten times their width. Because of focal spot limitations, current commercial orthovoltage devices are simply not capable of creating such arrays at dose rates high enough for effective treatment while maintaining the microbeam pattern necessary to retain the high therapeutic ratio of the technique. Therefore, the development of a compact MRT device using carbon nanotube (CNT) cathode based X-ray technology is presented here. CNT cathodes have been shown to be capable of creating novel focal spot arrays on a single anode while being robust enough for long-term use in X-ray tubes. Using these cathodes, an X-ray tube with a single focal line has been created for the delivery of MRT dose distributions in radiobiological studies on small animals. In this work, the development process and final design of this specialized device will be detailed, along with the optimization and stabilization of its use for small animal studies. In addition, a detailed characterization of its final capabilities will be given; including a comprehensive measurement of its X-ray focal line dimensions, a description and evaluation of its collimator alignment and microbeam dimensions, and a full-scale phantom-based quantification of its dosimetric output. Finally, future project directions will be described briefly along with plans for a second generation device. Based on the results of this work, it is the author's belief that compact CNT MRT devices have definite commercialization potential for radiobiological research.

Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

NASA Astrophysics Data System (ADS)

Okuyama, Katsushi; Komatsu, Hisanori; Yamamoto, Hiroko; Pereira, Patricia N. R.; Bedran-Russo, Ana K.; Nomachi, Masaharu; Sato, Takahiro; Sano, Hidehiko

2011-10-01

The use of fluoride for the prevention of caries is based on the transformation of hydroxylapatite to fluoroapatite in the presence of fluoride ions, thereby strengthening tooth structure. Adhesion of dentin and resin composite (tooth-colored restoration material) requires a dentin bonding system, since resin composite is not able to adhere to dentin directly. Demineralization of dentin by acid etching is an important step in the dentin bonding system, however, demineralization also introduces weaknesses in tooth structure. If the demineralized dentin could be strengthened by the application of fluoride, then the dentin-resin composite bond strength might also improve. To test this hypothesis, the present study evaluated the influence of fluoride applications on the strength of the dentin-resin composite bond by (1) tensile strength testing analyses, (2) SEM analyses of tooth structure, and (3) detection of calcium (Ca) and fluorine (F) distribution patterns by micro proton-induced X-ray emission (μ-PIXE) and micro proton-induced gamma-ray emission (μ-PIGE) analyses conducted at the Takasaki Ion Accelerators for Advanced Radiation Application (TIARA) at the Takasaki Advanced Radiation Research Institute (TARRI). In this study, the dentin in extracted human molars was exposed by grinding and the dentin was etched with 35% phosphoric acid. Fluoride was applied at two concentrations, 0.022% (100 ppm F) and 2.21% (10,000 ppm F) NaF solution, for two time periods, 30 and 60 s, prior to bonding the resin composite with the treated dentin. Controls were prepared in the same manner, but without the fluoride application. Bond strength was measured with a micro-tensile testing unit, and the fluorine and calcium distributions at the interface between dentin and resin composite were detected by μ-PIGE and μ-PIXE analysis, respectively. Results indicate that the 10,000 ppm F applications resulted in higher bond strengths than observed in either the 100 ppm F applications or the control group. In addition, PIGE analyses showed high concentrations of fluorine in the hybrid bonding layer of the 10,000 ppm F samples, suggesting that the fluorine contributes to the strength of the dentin-resin composite bond. Detection of fluoroapatite within the hybrid bonding layer suggests that bond strength involves remineralization processes.

High Resolution Quantitative Microbeam Analysis of Ir-coated Geological Specimens Using Conventionally Coated Standards

NASA Astrophysics Data System (ADS)

Armstrong, J. T.; Crispin, K. L.

2012-12-01

Traditionally, quantitative electron microbeam analyses of insulating specimens are performed after coating the materials with thin conducting layers of carbon. For x-ray lines greater than 1 keV in energy and beam voltages in excess of 10 keV, the results are insensitive to the exact thickness of the carbon coat. High resolution imaging, low voltage analysis, and analysis of specimens containing low levels of carbon require the use of substitute conductive coats. Typical substitutes for carbon coats (e.g., Au, Au-Pd, Cr, Al) require either using similarly coated standards or substantial corrections to be applied. Even when using modern multi-layer correction algorithms or Monte Carlo calculations, significant errors can result (e.g., Armstrong 2009, Armstrong and Crispin, 2012). We propose the use of ultra-thin layers of Ir as a substitute for C in the analysis of insulating geological specimens. Ir has been found to be an excellent coating material for high resolution imaging (e.g., Echlin, 2009). Sputtered layers as thin as 0.5 nm are found to be conductive, and layers of just a few nm provide good protection against beam damage with sub-nm grain size (Sebring et al., 1999). We have analyzed a series of geological materials with Ir coats between 1 - 8 nm and found similar levels of effects on emitted x-ray intensities as produced with typical carbon coat thicknesses (10-25 nm). E.g., for Ir thicknesses less than 5 nm, the reduction of intensity for x-ray lines between 1 and 7 keV are between 1-3% for a beam energy of 15 keV. The reduction in intensity for higher-energy lines such as Fe-K is actually less than produced by typical C-coats. We will present the results of these experiments and propose simple algorithmic equations which fit these data.

The PixFEL project: Progress towards a fine pitch X-ray imaging camera for next generation FEL facilities

NASA Astrophysics Data System (ADS)

Rizzo, G.; Batignani, G.; Benkechkache, M. A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Dalla Betta, G.-F.; Fabris, L.; Forti, F.; Grassi, M.; Lodola, L.; Malcovati, P.; Manghisoni, M.; Mendicino, R.; Morsani, F.; Paladino, A.; Pancheri, L.; Paoloni, E.; Ratti, L.; Re, V.; Traversi, G.; Vacchi, C.; Verzellesi, G.; Xu, H.

2016-07-01

The INFN PixFEL project is developing the fundamental building blocks for a large area X-ray imaging camera to be deployed at next generation free electron laser (FEL) facilities with unprecedented intensity. Improvement in performance beyond the state of art in imaging instrumentation will be explored adopting advanced technologies like active edge sensors, a 65 nm node CMOS process and vertical integration. These are the key ingredients of the PixFEL project to realize a seamless large area focal plane instrument composed by a matrix of multilayer four-side buttable tiles. In order to minimize the dead area and reduce ambiguities in image reconstruction, a fine pitch active edge thick sensor is being optimized to cope with very high intensity photon flux, up to 104 photons per pixel, in the range from 1 to 10 keV. A low noise analog front-end channel with this wide dynamic range and a novel dynamic compression feature, together with a low power 10 bit analog to digital conversion up to 5 MHz, has been realized in a 110 μm pitch with a 65 nm CMOS process. Vertical interconnection of two CMOS tiers will be also explored in the future to build a four-side buttable readout chip with high density memories. In the long run the objective of the PixFEL project is to build a flexible X-ray imaging camera for operation both in burst mode, like at the European X-FEL, or in continuous mode with the high frame rates anticipated for future FEL facilities.

Graphitized silicon carbide microbeams: wafer-level, self-aligned graphene on silicon wafers

NASA Astrophysics Data System (ADS)

Cunning, Benjamin V.; Ahmed, Mohsin; Mishra, Neeraj; Ranjbar Kermany, Atieh; Wood, Barry; Iacopi, Francesca

2014-08-01

Currently proven methods that are used to obtain devices with high-quality graphene on silicon wafers involve the transfer of graphene flakes from a growth substrate, resulting in fundamental limitations for large-scale device fabrication. Moreover, the complex three-dimensional structures of interest for microelectromechanical and nanoelectromechanical systems are hardly compatible with such transfer processes. Here, we introduce a methodology for obtaining thousands of microbeams, made of graphitized silicon carbide on silicon, through a site-selective and wafer-scale approach. A Ni-Cu alloy catalyst mediates a self-aligned graphitization on prepatterned SiC microstructures at a temperature that is compatible with silicon technologies. The graphene nanocoating leads to a dramatically enhanced electrical conductivity, which elevates this approach to an ideal method for the replacement of conductive metal films in silicon carbide-based MEMS and NEMS devices.

On the Nonlinear Dynamics of a Tunable Shock Micro-switch

NASA Astrophysics Data System (ADS)

Azizi, Saber; Javaheri, Hamid; Ghanati, Parisa

2016-12-01

A tunable shock micro-switch based on piezoelectric excitation is proposed in this study. This model includes a clamped-clamped micro-beam sandwiched with two piezoelectric layers throughout the entire length. Actuation of the piezoelectric layers via a DC voltage leads to an initial axial force in the micro-beam and directly affects on its overall bending stiffness; accordingly enables two-side tuning of both the trigger time and threshold shock. The governing motion equation, in the presence of an electrostatic actuation and a shock wave, is derived using Hamilton's principle. We employ the finite element method based on the Galerkin technique to obtain the temporal and phase responses subjected to three different shock waves including half sine, triangular and rectangular forms. Subsequently, we investigate the effect of the piezoelectric excitations on the threshold shock amplitude and trigger time.

PIEX and neurological diseases

NASA Astrophysics Data System (ADS)

Van Rinsvelt, H. A.; Hurd, R. W.; Kondoro, J. W. A.; Andres, J. M.; Mickle, J. P.; Wilder, B. J.; Maenhaut, W.; De Reu, L.

1984-04-01

Preliminary studies in our laboratories indicated alterations of specific trace metals in humans and animals treated with valproic acid (VPA), an anticonvulsant, and in animals treated with 4-pentenoic acid (4-PA), a fatty acid which produces a Reyes Syndrome-like condition. In this study, we report the results of PIXE analysis of plasma, liver, and brain of rats treated with VPA and 4-PA. Tissue specific changes in selenium, zinc and calcium may underly the pathophysiological changes produced by these chemicals.

Biodosimetric quantification of short-term synchrotron microbeam versus broad-beam radiation damage to mouse skin using a dermatopathological scoring system

PubMed Central

Priyadarshika, R C U; Crosbie, J C; Kumar, B; Rogers, P A W

2011-01-01

Objectives Microbeam radiotherapy (MRT) with wafers of microscopically narrow, synchrotron generated X-rays is being used for pre-clinical cancer trials in animal models. It has been shown that high dose MRT can be effective at destroying tumours in animal models, while causing unexpectedly little damage to normal tissue. The aim of this study was to use a dermatopathological scoring system to quantify and compare the acute biological response of normal mouse skin with microplanar and broad-beam (BB) radiation as a basis for biological dosimetry. Method The skin flaps of three groups of mice were irradiated with high entrance doses (200 Gy, 400 Gy and 800 Gy) of MRT and BB and low dose BB (11 Gy, 22 Gy and 44 Gy). The mice were culled at different time-points post-irradiation. Skin sections were evaluated histologically using the following parameters: epidermal cell death, nuclear enlargement, spongiosis, hair follicle damage and dermal inflammation. The fields of irradiation were identified by γH2AX-positive immunostaining. Results The acute radiation damage in skin from high dose MRT was significantly lower than from high dose BB and, importantly, similar to low dose BB. Conclusion The integrated MRT dose was more relevant than the peak or valley dose when comparing with BB fields. In MRT-treated skin, the apoptotic cells of epidermis and hair follicles were not confined to the microbeam paths. PMID:21849367

Fast simulation of Proton Induced X-Ray Emission Tomography using CUDA

NASA Astrophysics Data System (ADS)

Beasley, D. G.; Marques, A. C.; Alves, L. C.; da Silva, R. C.

2013-07-01

A new 3D Proton Induced X-Ray Emission Tomography (PIXE-T) and Scanning Transmission Ion Microscopy Tomography (STIM-T) simulation software has been developed in Java and uses NVIDIA™ Common Unified Device Architecture (CUDA) to calculate the X-ray attenuation for large detector areas. A challenge with PIXE-T is to get sufficient counts while retaining a small beam spot size. Therefore a high geometric efficiency is required. However, as the detector solid angle increases the calculations required for accurate reconstruction of the data increase substantially. To overcome this limitation, the CUDA parallel computing platform was used which enables general purpose programming of NVIDIA graphics processing units (GPUs) to perform computations traditionally handled by the central processing unit (CPU). For simulation performance evaluation, the results of a CPU- and a CUDA-based simulation of a phantom are presented. Furthermore, a comparison with the simulation code in the PIXE-Tomography reconstruction software DISRA (A. Sakellariou, D.N. Jamieson, G.J.F. Legge, 2001) is also shown. Compared to a CPU implementation, the CUDA based simulation is approximately 30× faster.

The international fine aerosol networks

NASA Astrophysics Data System (ADS)

Cahill, Thomas A.

1993-04-01

The adoption by the United States of a PIXE-based protocol for its fine aerosol network, after open competitions involving numerous laboratories and methods, has encouraged cooperation with other countries possessing similar capabilities and similar needs. These informal cooperative programs, involving about a dozen countries at the end of 1991, almost all use PIXE as a major component of the analytical protocols. The University of California, Davis, Air Quality Group assisted such programs through indefinite loans of a quality assurance sampler, the IMPROVE Channel A, and analyses at no cost of a small fraction of the samples taken in a side-by-side configuration. In December 1991, the World Meteorological Organization chose a protocol essentially identical to IMPROVE for the Global Atmospheric Watch (GAW) network and began deploying units, the IMPROVE Channel A, to sites around the world. Preferred analyses include fine (less than about 2.5 μm) mass, ions by ion chromatography and elements by PIXE + PESA (or, lacking that, XRF). This paper will describe progress in both programs, giving examples of the utility of the data and projecting the future expansion of the network to about 20 GAW sites by 1994.

NASCAP simulation of PIX 2 experiments

NASA Technical Reports Server (NTRS)

Roche, J. C.; Mandell, M. J.

1985-01-01

The latest version of the NASCAP/LEO digital computer code used to simulate the PIX 2 experiment is discussed. NASCAP is a finite-element code and previous versions were restricted to a single fixed mesh size. As a consequence the resolution was dictated by the largest physical dimension to be modeled. The latest version of NASCAP/LEO can subdivide selected regions. This permitted the modeling of the overall Delta launch vehicle in the primary computational grid at a coarse resolution, with subdivided regions at finer resolution being used to pick up the details of the experiment module configuration. Langmuir probe data from the flight were used to estimate the space plasma density and temperature and the Delta ground potential relative to the space plasma. This information is needed for input to NASCAP. Because of the uncertainty or variability in the values of these parameters, it was necessary to explore a range around the nominal value in order to determine the variation in current collection. The flight data from PIX 2 were also compared with the results of the NASCAP simulation.

New markers to identify the provenance of lapis lazuli: trace elements in pyrite by means of micro-PIXE

NASA Astrophysics Data System (ADS)

Re, A.; Angelici, D.; Lo Giudice, A.; Maupas, E.; Giuntini, L.; Calusi, S.; Gelli, N.; Massi, M.; Borghi, A.; Gallo, L. M.; Pratesi, G.; Mandò, P. A.

2013-04-01

Lapis lazuli has been used for glyptics and carving since the fifth millennium BC to produce jewels, amulets, seals, inlays, etc; the identification of the origin of the stone used for carving artworks may be valuable for reconstructing old trade routes. Since ancient lapis lazuli art objects are precious, only non-destructive techniques can be used to identify their provenance, and ion beam analysis (IBA) techniques allow us to characterise this stone in a fully non-invasive way. In addition, by using an ion microprobe, we have been able to focus the analysis on single crystals, as their typical dimensions may range from a few microns to hundreds of microns. Provenance markers, identified in previous IBA studies and already presented elsewhere, were based on the presence/absence of mineral phases, on the presence/quantity of trace elements inside a phase and on characteristic features of the luminescence spectra. In this work, a systematic study on pyrite crystals, a common accessory mineral in lapis lazuli, was carried out, following a multi-technique approach: optical microscopy and SEM-EDX to select crystals for successive trace element micro-PIXE measurements at two Italian facilities, the INFN Laboratori Nazionali di Legnaro and the INFN LABEC laboratory in Firenze. The results of this work allowed us to obtain new markers for lapis lazuli provenance identification.

Source apportionment by PMF on elemental concentrations obtained by PIXE analysis of PM10 samples collected at the vicinity of lignite power plants and mines in Megalopolis, Greece

NASA Astrophysics Data System (ADS)

Manousakas, M.; Diapouli, E.; Papaefthymiou, H.; Migliori, A.; Karydas, A. G.; Padilla-Alvarez, R.; Bogovac, M.; Kaiser, R. B.; Jaksic, M.; Bogdanovic-Radovic, I.; Eleftheriadis, K.

2015-04-01

Particulate matter (PM) is an important constituent of atmospheric pollution especially in areas under the influence of industrial emissions. Megalopolis is a small city of 10,000 inhabitants located in central Peloponnese in close proximity to three coal opencast mines and two lignite fired power plants. 50 PM10 samples were collected in Megalopolis during the years 2009-11 for elemental and multivariate analysis. For the elemental analysis PIXE was used as one of the most effective techniques in APM analytical characterization. Altogether, the concentrations of 22 elements (Z = 11-33), whereas Black Carbon was also determined for each sample using a reflectometer. Factorization software was used (EPA PMF 3.0) for source apportionment analysis. The analysis revealed that major emission sources were soil dust 33% (7.94 ± 0.27 μg/m3), biomass burning 19% (4.43 ± 0.27 μg/m3), road dust 15% (3.63 ± 0.37 μg/m3), power plant emissions 13% (3.01 ± 0.44 μg/m3), traffic 12% (2.82 ± 0.37 μg/m3), and sea spray 8% (1.99 ± 0.41 μg/m3). Wind trajectories have suggested that metals associated with emission from the power plants came mainly from west and were connected with the locations of the lignite mines located in this area. Soil resuspension, road dust and power plant emissions increased during the warm season of the year, while traffic/secondary, sea spray and biomass burning become dominant during the cold season.

Elemental Analysis of Beryllium Samples Using a Microzond-EGP-10 Unit

NASA Astrophysics Data System (ADS)

Buzoverya, M. E.; Karpov, I. A.; Gorodnov, A. A.; Shishpor, I. V.; Kireycheva, V. I.

2017-12-01

Results concerning the structural and elemental analysis of beryllium samples obtained via different technologies using a Microzond-EGP-10 unit with the help of the PIXE and RBS methods are presented. As a result, the overall chemical composition and the nature of inclusions were determined. The mapping method made it possible to reveal the structural features of beryllium samples: to select the grains of the main substance having different size and chemical composition, to visualize the interfaces between the regions of different composition, and to describe the features of the distribution of impurities in the samples.

Energy dependent features of X-ray signals in a GridPix detector

NASA Astrophysics Data System (ADS)

Krieger, C.; Kaminski, J.; Vafeiadis, T.; Desch, K.

2018-06-01

We report on the calibration of an argon/isobutane (97.7%/2.3%)-filled GridPix detector with soft X-rays (277 eV to 8 keV) using the variable energy X-ray source of the CAST Detector Lab at CERN. We study the linearity and energy resolution of the detector using both the number of pixels hit and the total measured charge as energy measures. For the latter, the energy resolution σE / E is better than 10% (20%) for energies above 2 keV (0.5 keV). Several characteristics of the recorded events are studied.

PIXE in experimental archaeometry

NASA Astrophysics Data System (ADS)

Demortier, Guy; Van Oystaeyen, Bruno; Boullar, Annick

1984-04-01

A new step in the understanding of the degree of expertise in soldering in antiquity is discussed. It takes into account results from analyses of noncommercial alloys manufactured with techniques known in early times. The procedure involves only rudimentary means: mixture in a charcoal furnace of gold (or natural gold alloys such as electrum) with a natural cadmium mineral whose colour is close to that of gold and to that of gold solders described in the oldest metallurgical handbooks. PIXE both in nonvacuum and in microprobe arrangements is used to analyse ancient artifacts and soldering alloys of commercial origin and those manufactured by this "ancient procedure."

A GridPix-based X-ray detector for the CAST experiment

NASA Astrophysics Data System (ADS)

Krieger, C.; Kaminski, J.; Lupberger, M.; Desch, K.

2017-09-01

The CAST experiment has been searching for axions and axion-like particles for more than 10 years. The continuous improvements in the detector designs have increased the physics reach of the experiment far beyond what was originally conceived. As part of this development, a new detector based on a GridPix readout had been developed in 2014 and was mounted on the CAST experiment during the end of the data taking period of 2014 and the complete period in 2015. We report on the detector design, its advantages and the performance during both periods.

Proceedings of the 5th Symposium on applied surface analysis

NASA Astrophysics Data System (ADS)

Grant, J. T.

1984-04-01

The 5th Symposium on Applied Surface Analysis was held at the University of Dayton, 8-10 June 1983. This Symposium was held to meet a need, namely to show the transition between basic surface science research and applications of this research to areas of Department of Defense interest. Areas receiving special attention at this Symposium were chemical bonding and reactions at metal-semiconductors interfaces, surface analysis and the tribological processes of ion implanted materials, microbeam analysis and laser ionization of sputtered neutrals. Other topics discussed included adsorption, adhesion, corrosion, wear and thin films. Approximately 110 scientists active in the field of surface analysis participated in the Symposium. Four scientists presented invited papers at the Symposium. There were 29 contributed presentations. The proceedings of the Symposium are being published in a special issue of the journal, Applications of Surface Science, by North-Holland Publishing Company.

Analysis of Atmospheric Aerosols Collected in an Urban Area in Upstate NY Using Proton Induced X-ray Emission (PIXE) Spectroscopy

NASA Astrophysics Data System (ADS)

Smith, Jeremy; Ali, Salina; Nadareski, Benjamin; Safiq, Alexandrea; Yoskowitz, Joshua; Labrake, Scott; Vineyard, Michael

2013-10-01

We examined atmospheric aerosol samples collected in Schenectady NY for evidence of pollution. We collected aerosol samples using a nine stage cascade impactor which distributes the particulate matter by aerodynamic size onto 7.5 μm Kapton foils. We then used a 1MV electrostatic Pelletron accelerator to produce a 2.2 MeV proton beam to hit the impacted foils. X-ray intensity versus energy spectra were collected using an Amptek x-ray detector where the x-rays are produced from the proton beam interacting with the sample. This is called PIXE. The elemental composition and concentrations of the elements present in the aerosol samples were determined using a software package called GUPIX. We have found elements ranging from Al to Pb and in particular have found significant amounts of Pb and Br on some of our impacted foils, with a Br/Pb ratio of 0.6 +/- 0.2 which agrees with previous studies. This result suggests the presence of leaded aviation fuel perhaps due to the proximity of the collection site to a small airport with a significant amount of general aviation traffic. Union College.

PIXE Analysis of Metal Hull Bolts From HMB DeBraak

NASA Astrophysics Data System (ADS)

Correll, Francis D.; Cole, Lord K.; Slater, Charles J.; Vanhoy, Jeffrey R.; Fithian, Charles H.

2009-03-01

HMB DeBraak was a 16-gun British brig-sloop that sank in a squall on May 25, 1798 off Cape Henlopen, Delaware. Silt covered the wooden hull shortly after it sank, preserving it until DeBraak was raised in 1986. The items recovered from the ship include metal bolts that held the hull together. We used PIXE to measure the compositions of 45 of the bolts and found that they are nearly pure copper (98.3% on average), with most also containing small amounts of iron (0.87%), nickel (0.039%), arsenic (0.43%), silver (0.089%), lead (0.18%), and bismuth (0.12%). A few contain a little indium, tin, or antimony, but none contain zinc above the quantization level. The compositions are similar to those reported for 18th-century English copper, but different from several copper alloys also used to make hull bolts. We conclude that, when DeBraak was last fitted out in 1795-1797, the Royal Navy was still using bolts similar to William Forbes's mechanically hardened pure copper bolts. Forbes's process represents the successful innovation and application of new technology in Royal Navy ships during the wars of the late 18th century.

Elemental micro-PIXE mapping of hypersensitive lesions in Lagenaria sphaerica (Cucurbitaceae) resistant to Sphaerotheca fuliginea (powdery mildew)

NASA Astrophysics Data System (ADS)

Weiersbye-Witkowski, I. M.; Przybylowicz, W. J.; Straker, C. J.; Mesjasz-Przybylowicz, J.

1997-07-01

Genotypes of the Southern African cucurbit, Lagenaria sphaerica, that are resistant to powdery-mildew ( Sphaerotheca fuliginea) exhibit foliar hypersensitive (HS) lesions on inoculation with this fungal pathogen. Elemental distributions across radially symmetrical HS lesions, surrounding unlesioned leaf tissue and uninoculated leaf tissue, were obtained using the true elemental imaging system (Dynamic Analysis) of the NAC Van de Graaff nuclear microprobe. Raster scans of 3 MeV protons were complemented by simultaneous PIXE and BS point analyses. The composition of cellulose (C 6H 10O 5) was used as constant matrix composition for scans, and the sample thickness was found from BS spectra. Si and elements heavier than Ca contributed to matrix composition within HS lesions and the locally elevated Ca raised the limits of detection for some trace metals of interest. In comparison to uninoculated tissue, inoculated tissue was characterised by higher overall concentrations of all measured elements except Cu. Fully developed, 6 day-old HS lesions and the surrounding tissue could be divided into five zones, centred on the fungal infection site. Each zone was characterized by distinct local elemental distributions (either depletion, or accumulation to potentially phytotoxic levels).

Measurement of trace elements in tree rings using the PIXE method

NASA Astrophysics Data System (ADS)

Aoki, Toru; Katayama, Yukio; Kagawa, Akira; Koh, Susumu; Yoshida, Kohji

1998-03-01

Standard materials were prepared in order to calculate element concentrations in tree samples using the particle induced X-ray emission (PIXE) method. Five standard solutions (1) Ti, Fe, Cu, As, Rb, Sr; (2) Ca, V, Co, Zn, As, Rb; (3) Ti, Mn, Ni, As, Sr; (4) K, Mn, Co, As, Rb, Sr; and (5) Ca, Mn, Cu, As, Rb, Sr, were added to filter papers. The dried filter papers were used as standard samples. Pellets of Pepperbush leaves (National Institute for Environmental Studies (NIES)) and Peach leaves (National Institute of Standards and Technology (NIST)) were used as references. The peak counts of Ca, Mn, Cu, Zn, Rb, and Sr in samples taken from a kaki ( Diospros kaki Thunb.) were measured and the concentrations (ppm) of the elements were calculated using the yield curve obtained from the standard filter papers. The concentrations of Mn, Zn, Rb, and Ca were compared with the data obtained from a separate INAA analysis. Concentrations of Mn, Zn, and Ca obtained by both methods were almost the same, but the concentrations of Rb differed slightly. The amounts of trace elements in samples taken from a sugi ( Cryptomeria japonica D. Don) were also measured.

Characterisation of traffic-generated particulate matter in Copenhagen

NASA Astrophysics Data System (ADS)

Wåhlin, Peter; Berkowicz, Ruwim; Palmgren, Finn

Fine and coarse fraction PM was simultaneously sampled with Dichotomous Stacked Filter Units at a road site and at an urban background site during both summer and winter periods. The collected mass was determined gravimetrically, and the contents of 26 elements were measured by Proton-Induced X-ray Emission (PIXE). NO x was monitored continuously at both sites. The road increments (road concentrations minus urban background concentrations) of PIXE elements, PM and NO x were analysed using the Constrained Physical Receptor Model (COPREM). Good agreement between the measured data and the model was achieved in both size fractions using four well-separated source profiles representing the emissions from exhaust, road/tyres, brakes and road salt. The analysis showed that the particles created by brake abrasion have aerodynamic diameters in the inhalable size range around 2.8 μm. This particle diameter is common mass median for a long list of heavy metals that are apportioned to the brakes source: Cr, Fe, Cu, Zn, Zr, Mo, Sn, Sb, Ba and Pb. Other significant contributions of Al, Si, K, Ca, Ti, Mn, Fe, Zn and Sr, mostly in the coarse particle fraction, are apportioned to the road/tyres source.

Trace elemental analysis in cancer-afflicted tissues of penis and testis by PIXE technique

NASA Astrophysics Data System (ADS)

Naga Raju, G. J.; John Charles, M.; Bhuloka Reddy, S.; Sarita, P.; Seetharami Reddy, B.; Rama Lakshmi, P. V. B.; Vijayan, V.

2005-04-01

PIXE technique was employed to estimate the trace elemental concentrations in the biological samples of cancerous penis and testis. A 3 MeV proton beam was employed to excite the samples. From the present results it can be seen that the concentrations of Cl, Fe and Co are lower in the cancerous tissue of the penis when compared with those in normal tissue while the concentrations of Cu, Zn and As are relatively higher. The concentrations of K, Ca, Ti, Cr, Mn, Br, Sr and Pb are in agreement within standard deviations in both cancerous and normal tissues. In the cancerous tissue of testis, the concentrations of K, Cr and Cu are higher while the concentrations of Fe, Co and Zn are lower when compared to those in normal tissue of testis. The concentrations of Cl, Ca, Ti and Mn are in agreement in both cancerous and normal tissues of testis. The higher levels of Cu lead to the development of tumor. Our results also support the underlying hypothesis of an anticopper, antiangiogenic approach to cancer therapy. The Cu/Zn ratios of both penis and testis were higher in cancer tissues compared to that of normal.

Trace elemental analysis of bituminuos coals using the Heidelberg proton microprobe

USGS Publications Warehouse

Chen, J.R.; Kneis, H.; Martin, B.; Nobiling, R.; Traxel, K.; Chao, E.C.T.; Minkin, J.A.

1981-01-01

Trace elements in coal can occur as components of either the organic constituents (macerals) or the inorganic constituents (minerals). Studies of the concentrations and distribution of the trace elements are vital to understanding the geochemical millieu in which the coal was formed and in evaluating the attempts to recover rare but technologically valuable metals. In addition, information on the trace element concentrations is important in predicting the environmental impact of burning particular coals, as many countries move toward greater utilization of coal reserves for energy production. Traditionally, the optical and the electron microscopes and more recently the electron microprobe have been used in studying the components of coal. The proton-induced X-ray emission (PIXE) microprobe offers a new complementary approach with an order of magnitude or more better minimum detection limit. We present the first measurements with a PIXE microprobe of the trace element concentrations of bituminous coal samples. Elemental analyses of the coal macerals-vitrinite, exinite, and inertinite-are discussed for three coal samples from the Eastern U.S.A., three samples from the Western U.S.A., and one sample from the Peoples Republic of China. ?? 1981.

Multiscale Laboratory Infrastructure and Services to users: Plans within EPOS

NASA Astrophysics Data System (ADS)

Spiers, Chris; Willingshofer, Ernst; Drury, Martyn; Funiciello, Francesca; Rosenau, Matthias; Scarlato, Piergiorgio; Sagnotti, Leonardo; EPOS WG6, Corrado Cimarelli

2015-04-01

The participant countries in EPOS embody a wide range of world-class laboratory infrastructures ranging from high temperature and pressure experimental facilities, to electron microscopy, micro-beam analysis, analogue modeling and paleomagnetic laboratories. Most data produced by the various laboratory centres and networks are presently available only in limited "final form" in publications. Many data remain inaccessible and/or poorly preserved. However, the data produced at the participating laboratories are crucial to serving society's need for geo-resources exploration and for protection against geo-hazards. Indeed, to model resource formation and system behaviour during exploitation, we need an understanding from the molecular to the continental scale, based on experimental data. This contribution will describe the plans that the laboratories community in Europe is making, in the context of EPOS. The main objectives are: • To collect and harmonize available and emerging laboratory data on the properties and processes controlling rock system behaviour at multiple scales, in order to generate products accessible and interoperable through services for supporting research activities. • To co-ordinate the development, integration and trans-national usage of the major solid Earth Science laboratory centres and specialist networks. The length scales encompassed by the infrastructures included range from the nano- and micrometer levels (electron microscopy and micro-beam analysis) to the scale of experiments on centimetre sized samples, and to analogue model experiments simulating the reservoir scale, the basin scale and the plate scale. • To provide products and services supporting research into Geo-resources and Geo-storage, Geo-hazards and Earth System Evolution. If the EPOS Implementation Phase proposal presently under construction is successful, then a range of services and transnational activities will be put in place to realize these objectives.

Two VLT 8.2-m Unit Telescopes in Action

NASA Astrophysics Data System (ADS)

1999-04-01

Visitors at ANTU - Astronomical Images from KUEYEN The VLT Control Room at the Paranal Observatory is becoming a busy place indeed. From here, two specialist teams of ESO astronomers and engineers now operate two VLT 8.2-m Unit Telescopes in parallel, ANTU and KUEYEN (formerly UT1 and UT2, for more information about the naming and the pronunciation, see ESO Press Release 06/99 ). Regular science observations have just started with the first of these giant telescopes, while impressive astronomical images are being obtained with the second. The work is hard, but the mood in the control room is good. Insiders claim that there have even been occasions on which the groups have had a friendly "competition" about which telescope makes the "best" images! The ANTU-team has worked with the FORS multi-mode instrument , their colleagues at KUEYEN use the VLT Test Camera for the ongoing tests of this new telescope. While the first is a highly developed astronomical instrument with a large-field CCD imager (6.8 x 6.8 arcmin 2 in the normal mode; 3.4 x 3.4 arcmin 2 in the high-resolution mode), the other is a less complex CCD camera with a smaller field (1.5 x 1.5 arcmin 2 ), suited to verify the optical performance of the telescope. As these images demonstrate, the performance of the second VLT Unit Telescope is steadily improving and it may not be too long before its optical quality will approach that of the first. First KUEYEN photos of stars and galaxies We present here some of the first astronomical images, taken with the second telescope, KUEYEN, in late March and early April 1999. They reflect the current status of the optical, electronic and mechanical systems, still in the process of being tuned. As expected, the experience gained from ANTU last year has turned out to be invaluable and has allowed good progress during this extremely delicate process. ESO PR Photo 19a/99 ESO PR Photo 19a/99 [Preview - JPEG: 400 x 433 pix - 160k] [Normal - JPEG: 800 x 866 pix - 457k] [High-Res - JPEG: 1985 x 2148 pix - 2.0M] ESO PR Photo 19b/99 ESO PR Photo 19b/99 [Preview - JPEG: 400 x 478 pix - 165k] [Normal - JPEG: 800 x 956 pix - 594k] [High-Res - JPEG: 3000 x 3583 pix - 7.1M] Caption to PR Photo 19a/99 : This photo was obtained with VLT KUEYEN on April 4, 1999. It is reproduced from an excellent 60-second R(ed)-band exposure of the innermost region of a globular cluster, Messier 68 (NGC 4590) , in the southern constellation Hydra (The Water-Snake). The distance to this 8-mag cluster is about 35,000 light years, and the diameter is about 140 light-years. The excellent image quality is 0.38 arcsec , demonstrating a good optical and mechanical state of the telescope, already at this early stage of the commissioning phase. The field measures about 90 x 90 arcsec 2. The original scale is 0.0455 pix/arcsec and there are 2048x2048 pixels in one frame. North is up and East is left. Caption to PR Photo 19b/99 : This photo shows the central region of spiral galaxy ESO 269-57 , located in the southern constellation Centaurus at a distance of about 150 million light-years. Many galaxies are seen in this direction at about the same distance, forming a loose cluster; there are also some fainter, more distant ones in the background. The designation refers to the ESO/Uppsala Survey of the Southern Sky in the 1970's during which over 15,000 southern galaxies were catalogued. ESO 269-57 is a tightly bound object of type Sar , the "r" referring to the "ring" that surrounds the bright centre, that is overexposed here. The photo is a composite, based on three exposures (Blue - 600 sec; Yellow-Green - 300 sec; Red - 300 sec) obtained with KUEYEN on March 28, 1999. The image quality is 0.7 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. ESO PR Photo 19c/99 ESO PR Photo 19c/99 [Preview - JPEG: 400 x 478 pix - 132k] [Normal - JPEG: 800 x 956 pix - 446k] [High-Res - JPEG: 3000 x 3583 pix - 4.6M] ESO PR Photo 19d/99 ESO PR Photo 19d/99 [Preview - JPEG: 400 x 454 pix - 86k] [Normal - JPEG: 800 x 907 pix - 301k] [High-Res - JPEG: 978 x 1109 pix - 282k] Caption to PR Photo 19c/99 : Somewhat further out in space, and right on the border between the southern constellations Hydra and Centaurus lies this knotty spiral galaxy, IC 4248 ; the distance is about 210 million light-years. It was imaged with KUEYEN on March 28, 1999, with the same filters and exposure times as used for Photo 19b/99. The image quality is 0.75 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. Caption to PR Photo 19d/99 : This is a close-up view of the double galaxy NGC 5090 (right) and NGC 5091 (left), in the southern constellation Centaurus. The first is a typical S0 galaxy with a bright diffuse centre, surrounded by a fainter envelope of stars (not resolved in this picture). However, some of the starlike objects seen in this region may be globular clusters (or dwarf galaxies) in orbit around NGC 5090. The other galaxy is of type Sa (the spiral structure is more developed) and is seen at a steep angle. The three-colour composite is based on frames obtained with KUEYEN on March 29, 1999, with the same filters and exposure times as used for Photo 19b/99. The image quality is 0.7 arcsec and the field is 90 x 90 arcsec 2. North is up and East is left. ( Note inserted on April 26: The original caption text identified the second galaxy as NGC 5090B - this error has now been corrected. ESO PR Photo 19e/99 ESO PR Photo 19e/99 [Preview - JPEG: 400 x 441 pix - 282k] [Normal - JPEG: 800 x 882 pix - 966k] [High-Res - JPEG: 3000 x 3307 pix - 6,4M] Caption to PR Photo 19e/99 : Wide-angle photo of the second 8.2-m VLT Unit Telescope, KUEYEN , obtained on March 10, 1999, with the main mirror and its cell in place at the bottom of the telescope structure. The Test Camera with which the astronomical images above were made, is positioned at the Cassegrain focus, inside this mirror cell. The Paranal Inauguration on March 5, 1999, took place under this telescope that was tilted towards the horizon to accommodate nearly 300 persons on the observing floor. Astronomical observations with ANTU have started On April 1, 1999, the first 8.2-m VLT Unit Telescope, ANTU , was "handed over" to the astronomers. Last year, about 270 observing proposals competed about the first, precious observing time at Europe's largest optical telescope and more than 100 of these were accommodated within the six-month period until the end of September 1999. The complete observing schedule is available on the web. These observations will be carried out in two different modes. During the Visitor Mode , the astronomers will be present at the telescope, while in the Service Mode , ESO observers perform the observations. The latter procedure allows a greater degree of flexibility and the possibility to assign periods of particularly good observing conditions to programmes whose success is critically dependent on this. The first ten nights at ANTU were allocated to service mode observations. After some initial technical problems with the instruments, these have now started. Already in the first night, programmes at ISAAC requiring 0.4 arcsec conditions could be satisfied, and some images better than 0.3 arcsec were obtained in the near-infrared . The first astronomers to use the telescope in visitors mode will be Professors Immo Appenzeller (Heidelberg, Germany; "Photo-polarimetry of pulsars") and George Miley (Leiden, The Netherlands; "Distant radio galaxies") with their respective team colleagues. How to obtain ESO Press Information ESO Press Information is made available on the World-Wide Web (URL: http://www.eso.org../ ). ESO Press Photos may be reproduced, if credit is given to the European Southern Observatory. Note also the dedicated webarea with VLT Information.

The Use of Ion Implantation for Materials Processing.

DTIC Science & Technology

1983-09-28

SPUTTERING ANALYSIS WITH PIXE.......................... 31 J.M. Lambert, P.A. Treado, D . Trbojevic ,2 R.G. Alias, A.R. Knudson, G.W. Reynolds and F.R...Lambert and P. . Treado I D . Trbojevic R. G. Allas and A. R. Knudson 3 G. W. Reynolds and F. R. Vozzo 4 IGeorgetown University Washington, D . C. and...D.C. 20057 and 20375 D . Trbojevic Georgetown University, Washington, D.C. 20057 R.G. Alias and A.R. Knudson Naval Research Laboratory, Washington, D.C

The Protein Micro-Crystallography Beamlines for Targeted Protein Research Program

NASA Astrophysics Data System (ADS)

Hirata, Kunio; Yamamoto, Masaki; Matsugaki, Naohiro; Wakatsuki, Soichi

In order to collect proper diffraction data from outstanding micro-crystals, a brand-new data collection system should be designed to provide high signal-to noise ratio in diffraction images. SPring-8 and KEK-PF are currently developing two micro-beam beamlines for Targeted Proteins Research Program by MEXT of Japan. The program aims to reveal the structure and function of proteins that are difficult to solve but have great importance in both academic research and industrial application. At SPring-8, a new 1-micron beam beamline for protein micro-crystallography, RIKEN Targeted Proteins Beamline (BL32XU), is developed. At KEK-PF a new low energy micro-beam beamline, BL-1A, is dedicated for SAD micro-crystallography. The two beamlines will start operation in the end of 2010. The present status of the research and development for protein micro-crystallography will be presented.

Synchrotron X-ray micro-beam studies of ancient Egyptian make-up

NASA Astrophysics Data System (ADS)

Martinetto, P.; Anne, M.; Dooryhée, E.; Drakopoulos, M.; Dubus, M.; Salomon, J.; Simionovici, A.; Walter, Ph.

2001-07-01

Vases full of make-up are most often present in the burial furniture of Egyptian tombs dated from the pharaonic period. The powdered cosmetics made of isolated grains are analysed to identify their trace element signature. From this signature we identify the provenance of the mineral ingredients in the make-up and we observe different impurities in products, which have been demonstrated as synthetic substances by previous works. Focused X-ray micro-beam ( 2×5 μm2) is successively tuned at 11 keV, below the L III absorption edge of Pb, and 31.8 keV for global characterisation of the metal impurities. The fluorescence signal integrated over each single grain is detected against the X-ray micro-diffraction pattern collected in transmission with a bi-dimensional detector. Furthermore, for galena grains rich in Zn, the XANES signal at the K-absorption edge of Zn shows its immediate nearest-neighbour environment.

The Race To X-ray Microbeam and Nanobeam Science

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ice, Gene E; Budai, John D; Pang, Judy

2011-01-01

X-ray microbeams are an emerging characterization tool with transformational implications for broad areas of science ranging from materials structure and dynamics, geophysics and environmental science to biophysics and protein crystallography. In this review, we discuss the race toward sub-10 nm- x-ray beams with the ability to penetrate tens to hundreds of microns into most materials and with the ability to determine local (crystal) structure. Examples of science enabled by current micro/nanobeam technologies are presented and we provide a perspective on future directions. Applications highlighted are chosen to illustrate the important features of various submicron beam strategies and to highlight themore » directions of current and future research. While it is clear that x-ray microprobes will impact science broadly, the practical limit for hard x-ray beam size, the limit to trace element sensitivity, and the ultimate limitations associated with near-atomic structure determinations are the subject of ongoing research.« less

Electrothermally actuated tunable clamped-guided resonant microbeams

NASA Astrophysics Data System (ADS)

Alcheikh, N.; Hajjaj, A. Z.; Jaber, N.; Younis, M. I.

2018-01-01

We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide-range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.

Single α-particle irradiation permits real-time visualization of RNF8 accumulation at DNA damaged sites

NASA Astrophysics Data System (ADS)

Muggiolu, Giovanna; Pomorski, Michal; Claverie, Gérard; Berthet, Guillaume; Mer-Calfati, Christine; Saada, Samuel; Devès, Guillaume; Simon, Marina; Seznec, Hervé; Barberet, Philippe

2017-01-01

As well as being a significant source of environmental radiation exposure, α-particles are increasingly considered for use in targeted radiation therapy. A better understanding of α-particle induced damage at the DNA scale can be achieved by following their tracks in real-time in targeted living cells. Focused α-particle microbeams can facilitate this but, due to their low energy (up to a few MeV) and limited range, α-particles detection, delivery, and follow-up observations of radiation-induced damage remain difficult. In this study, we developed a thin Boron-doped Nano-Crystalline Diamond membrane that allows reliable single α-particles detection and single cell irradiation with negligible beam scattering. The radiation-induced responses of single 3 MeV α-particles delivered with focused microbeam are visualized in situ over thirty minutes after irradiation by the accumulation of the GFP-tagged RNF8 protein at DNA damaged sites.

Microscopic stress characterisation of functional iron-based alloys by white X-ray microbeam diffraction

NASA Astrophysics Data System (ADS)

Kwon, E. P.; Sato, S.; Fujieda, S.; Shinoda, K.; Kajiwara, K.; Sato, M.; Suzuki, S.

2018-01-01

Microscopic residual stress evolution in an austenite (γ) grain during a shape-memory process in an Fe-Mn-Si-Cr alloy was investigated using the white X-ray microbeam diffraction technique. The stresses were measured on a coarse grain, which had an orientation near <144>, parallel to the tensile loading direction with a high Schmid factor for a martensitic transformation. The magnitude of the residual stresses in a grain of the sample, which was subjected to a 23 % tensile strain and subsequent shape-recovery heating, was found to be very small and comparable to that prior to tensile deformation. Measurements of the recovery strain and microstructural analyses using electron backscatter diffraction suggested that the low residual stresses could be attributed to the significant shape recovery caused by a highly reversible martensitic transformation in the grain with a particular orientation.

A smart microelectromechanical sensor and switch triggered by gas

NASA Astrophysics Data System (ADS)

Bouchaala, Adam; Jaber, Nizar; Shekhah, Osama; Chernikova, Valeriya; Eddaoudi, Mohamed; Younis, Mohammad I.

2016-07-01

There is an increasing interest to realize smarter sensors and actuators that can deliver a multitude of sophisticated functionalities while being compact in size and of low cost. We report here combining both sensing and actuation on the same device based on a single microstructure. Specifically, we demonstrate a smart resonant gas (mass) sensor, which in addition to being capable of quantifying the amount of absorbed gas, can be autonomously triggered as an electrical switch upon exceeding a preset threshold of absorbed gas. Toward this, an electrostatically actuated polymer microbeam is fabricated and is then functionalized with a metal-organic framework, namely, HKUST-1. The microbeam is demonstrated to absorb vapors up to a certain threshold, after which is shown to collapse through the dynamic pull-in instability. Upon pull-in, the microstructure can be made to act as an electrical switch to achieve desirable actions, such as alarming.

Supercritical nonlinear parametric dynamics of Timoshenko microbeams

NASA Astrophysics Data System (ADS)

Farokhi, Hamed; Ghayesh, Mergen H.

2018-06-01

The nonlinear supercritical parametric dynamics of a Timoshenko microbeam subject to an axial harmonic excitation force is examined theoretically, by means of different numerical techniques, and employing a high-dimensional analysis. The time-variant axial load is assumed to consist of a mean value along with harmonic fluctuations. In terms of modelling, a continuous expression for the elastic potential energy of the system is developed based on the modified couple stress theory, taking into account small-size effects; the kinetic energy of the system is also modelled as a continuous function of the displacement field. Hamilton's principle is employed to balance the energies and to obtain the continuous model of the system. Employing the Galerkin scheme along with an assumed-mode technique, the energy terms are reduced, yielding a second-order reduced-order model with finite number of degrees of freedom. A transformation is carried out to convert the second-order reduced-order model into a double-dimensional first order one. A bifurcation analysis is performed for the system in the absence of the axial load fluctuations. Moreover, a mean value for the axial load is selected in the supercritical range, and the principal parametric resonant response, due to the time-variant component of the axial load, is obtained - as opposed to transversely excited systems, for parametrically excited system (such as our problem here), the nonlinear resonance occurs in the vicinity of twice any natural frequency of the linear system; this is accomplished via use of the pseudo-arclength continuation technique, a direct time integration, an eigenvalue analysis, and the Floquet theory for stability. The natural frequencies of the system prior to and beyond buckling are also determined. Moreover, the effect of different system parameters on the nonlinear supercritical parametric dynamics of the system is analysed, with special consideration to the effect of the length-scale parameter.

Influence of cement thickness on resin-zirconia microtensile bond strength

PubMed Central

Lee, Tae-Hoon; Ahn, Jin-Soo; Shim, June-Sung; Han, Chong-Hyun

2011-01-01

PURPOSE The aim of this study was to evaluate the influence of resin cement thickness on the microtensile bond strength between zirconium-oxide ceramic and resin cement. MATERIALS AND METHODS Thirty-two freshly extracted molars were transversely sectioned at the deep dentin level and bonded to air-abraded zirconium oxide ceramic disks. The specimens were divided into 8 groups based on the experimental conditions (cement type: Rely X UniCem or Panavia F 2.0, cement thickness: 40 or 160 µm, storage: thermocycled or not). They were cut into microbeams and stored in 37℃ distilled water for 24 h. Microbeams of non-thermocycled specimens were submitted to a microtensile test, whereas those of thermocycled groups were thermally cycled for 18,000 times immediately before the microtensile test. Three-way ANOVA and Sheffe's post hoc tests were used for statistical analysis (α=95%). RESULTS All failures occurred at the resin-zirconia interface. Thermocycled groups showed lower microtensile bond strength than non-thermocycled groups (P<.001). Differences in cement thickness did not influence the resin-zirconia microtensile bond strength given the same resin cement or storage conditions (P>.05). The number of adhesive failures increased after thermocycling in all experimental conditions. No cohesive failure was observed in any experimental group. CONCLUSION When resin cements of adhesive monomers are applied over air-abraded zirconia restorations, the degree of fit does not influence the resin-zirconia microtensile bond strength. PMID:22053241

An ultra-thin Schottky diode as a transmission particle detector for biological microbeams.

PubMed

Grad, Michael; Harken, Andrew; Randers-Pehrson, Gerhard; Attinger, Daniel; Brenner, David J

2012-12-01

We fabricated ultrathin metal-semiconductor Schottky diodes for use as transmission particle detectors in the biological microbeam at Columbia University's Radiological Research Accelerator Facility (RARAF). The RARAF microbeam can deliver a precise dose of ionizing radiation in cell nuclei with sub-micron precision. To ensure an accurate delivery of charged particles, the facility currently uses a commercial charged-particle detector placed after the sample. We present here a transmission detector that will be placed between the particle accelerator and the biological specimen, allowing the irradiation of samples that would otherwise block radiation from reaching a detector behind the sample. Four detectors were fabricated with co-planar gold and aluminum electrodes thermally evaporated onto etched n-type crystalline silicon substrates, with device thicknesses ranging from 8.5 μm - 13.5 μm. We show coincident detections and pulse-height distributions of charged particles in both the transmission detector and the commercial detector above it. Detections are demonstrated at a range of operating conditions, including incoming particle type, count rate, and beam location on the detectors. The 13.5 μm detector is shown to work best to detect 2.7 MeV protons (H + ), and the 8.5 μm detector is shown to work best to detect 5.4 MeV alpha particles ( 4 He ++ ). The development of a transmission detector enables a range of new experiments to take place at RARAF on radiation-stopping samples such as thick tissues, targets that need immersion microscopy, and integrated microfluidic devices for handling larger quantities of cells and small organisms.

An ultra-thin Schottky diode as a transmission particle detector for biological microbeams

PubMed Central

Harken, Andrew; Randers-Pehrson, Gerhard; Attinger, Daniel; Brenner, David J.

2013-01-01

We fabricated ultrathin metal-semiconductor Schottky diodes for use as transmission particle detectors in the biological microbeam at Columbia University’s Radiological Research Accelerator Facility (RARAF). The RARAF microbeam can deliver a precise dose of ionizing radiation in cell nuclei with sub-micron precision. To ensure an accurate delivery of charged particles, the facility currently uses a commercial charged-particle detector placed after the sample. We present here a transmission detector that will be placed between the particle accelerator and the biological specimen, allowing the irradiation of samples that would otherwise block radiation from reaching a detector behind the sample. Four detectors were fabricated with co-planar gold and aluminum electrodes thermally evaporated onto etched n-type crystalline silicon substrates, with device thicknesses ranging from 8.5 μm – 13.5 μm. We show coincident detections and pulse-height distributions of charged particles in both the transmission detector and the commercial detector above it. Detections are demonstrated at a range of operating conditions, including incoming particle type, count rate, and beam location on the detectors. The 13.5 μm detector is shown to work best to detect 2.7 MeV protons (H+), and the 8.5 μm detector is shown to work best to detect 5.4 MeV alpha particles (4He++). The development of a transmission detector enables a range of new experiments to take place at RARAF on radiation-stopping samples such as thick tissues, targets that need immersion microscopy, and integrated microfluidic devices for handling larger quantities of cells and small organisms. PMID:24058378

The threshold number of protons to induce an adaptive response in zebrafish embryos.

PubMed

Choi, V W Y; Konishi, Teruaki; Oikawa, Masakazu; Cheng, S H; Yu, K N

2013-03-01

In this study, microbeam protons were used to provide the priming dose to induce an in vivo radioadaptive response (RAR) in the embryos of zebrafish, Danio rerio, against subsequent challenging doses provided by x-ray photons. The microbeam irradiation system (Single-Particle Irradiation System to Cell, acronym SPICE) at the National Institute of Radiological Sciences (NIRS), Japan, was employed. The embryos were dechorionated at 4 h post fertilisation (hpf) and irradiated at 5 hpf by microbeam protons. For each embryo, one irradiation point was chosen, to which 5, 10, 20, 30, 40, 50, 100, 200, 300 and 500 protons each with an energy of 3.4 MeV were delivered. The embryos were returned to the incubator until 10 hpf to further receive the challenging exposure, which was achieved using 2 Gy of x-ray irradiation, and then again returned to the incubator until 24 hpf for analyses. The levels of apoptosis in zebrafish embryos at 25 hpf were quantified through terminal dUTP transferase-mediated nick end-labelling (TUNEL) assay. The results revealed that at least 200 protons (with average radiation doses of about 300 and 650 mGy absorbed by an irradiated epithelial and deep cell, respectively) would be required to induce RAR in the zebrafish embryos in vivo. Our previous investigation showed that 5 protons delivered at 10 points on an embryo would already be sufficient to induce RAR in the zebrafish embryos. The difference was explained in terms of the radiation-induced bystander effect as well as the rescue effect.

μ-SRXRF characterization of Brazilian emeralds

NASA Astrophysics Data System (ADS)

Curado, J. F.; Radtke, M.; Buzanich, G.; Reinholz, U.; Riesemeier, H.; Guttler, R. A. S.; Rizzutto, M. A.

2014-04-01

The aim of the present study is to characterize emeralds from different mines of Brazil by using Synchrotron Radiation X-ray Fluorescence Microanalysis (μ-SRXRF). The advantage of this technique is that we can analyze a homogeneous, inclusion free area of the stone with the microbeam to distinguish the elemental fingerprint according to the provenance of the emerald. A total of 47 samples belonging to 5 different Brazilian mines were studied in this work and 28 elements were identified. By means of Principal Component Analysis (PCA) it is possible to build different groups according to the provenance of the stones, which allows to assign samples of unknown origin to the according mine.

Detection and Dynamic Analysis of Space Debris in the Geo Ring

NASA Astrophysics Data System (ADS)

Lacruz, E.; Abad, C.; Downes, J. J.; Casanova, D.; Tresaco, E.

2018-01-01

There are different populations of space debris (SD) in the geostationary (GEO) region. It is of great interest to know their dynamics, in order to contribute to aspects such as alerts against possible collisions, repositioning of GEO satellites or placing those satellites that come into service. In this contribution we present a study about the detection and dynamic analysis of SD located in the GEO ring. Using the telescopes of the Venezuelan Obseratory National (VON), a large amount of astrometric observations have been acquired. A preliminary dynamic analysis of them has been carried out, which evidences the average relative motion of these orbiters with a mean absolute error for coordinates of ≍ 0.09 pix.

Micro-PIXE studies of elemental distribution in Cd-accumulating Brassica juncea L.

NASA Astrophysics Data System (ADS)

Schneider, Thorsten; Haag-Kerwer, Angela; Maetz, Mischa; Niecke, Manfred; Povh, Bogdan; Rausch, Thomas; Schüßler, Arthur

1999-10-01

Brassica juncea L. is a high biomass producing crop plant, being able to accumulate Cd and other heavy metals in their roots and shoots. It is a good candidate for efficient phytoextraction of heavy metals - such as Cd - from polluted soils. PIXE and STIM analyses were applied to investigate Cd-uptake in roots and the resulting effects on the elemental distribution of Cd stressed plants. The axial distribution of trace elements as a function of distance from the root tip as well as the radial distribution within cross-sections were analysed. The results are compared with the elemental distribution in control plants.

Elemental and structural studies at the bone-cartilage interface

NASA Astrophysics Data System (ADS)

Bradley, D. A.; Kaabar, W.; Gundogdu, O.

2012-02-01

The techniques μProton-Induced X-and γ-ray Emission, μ-PIXE and μ-PIGE, were used to investigate trace and essential element distributions in sections of normal and osteoarthritic (OA) human femoral head. μ-PIGE yielded 2-D mappings of Na and F while Ca, Z, P and S were mapped by μ-PIXE. The concentration of chondroitin sulphate supporting functionality in healthy cartilage is significantly reduced in OA samples. Localised Zn points to osteoblastic/osteoclastic activity at the bone-cartilage interface. Small-angle X-ray scattering applied to decalcified OA-affected tissue showed spatial alterations of collagen fibres of decreased axial periodicity compared to normal collagen type I.

VizieR Online Data Catalog: Variables in Centaurus field F170 (Pietrukowicz+, 2012)

NASA Astrophysics Data System (ADS)

Pietrukowicz, P.; Minniti, D.; Alonso-Garcia; J.; Hempel, M.

2011-10-01

VJHKs photometry of stars in two VIMOS disc fields: F167 and F170. Data table with 333 variables detected in the field F170 in Centaurus. The optical observations were taken with the 8.2-m Unit Telescope 3 + VIMOS imager with a scale of 0.205"/pix at ESO Very Large Telescope at Paranal Observatory. Date of the observations: Apr 11-12, 2005. The infrared observations were obtained with the 4.1-m VISTA telescope + VIRCAM with a scale of 0.34"/pix also at Paranal Observatory. Date of the observations: Mar-Apr 2010. (4 data files).

Simultaneous quantification of amoxicillin and potassium clavulanate in different commercial drugs using PIXE technique

NASA Astrophysics Data System (ADS)

Bejjani, A.; Roumié, M.; Akkad, S.; El-Yazbi, F.; Nsouli, B.

2016-03-01

We have demonstrated, in previous studies that Particle Induced X-ray Emission (PIXE) is one of the most rapid and accurate choices for quantification of an active ingredient, in a solid drug, from the reactions induced on its specific heteroatom using pellets made from original tablets. In this work, PIXE is used, for the first time, for simultaneous quantification of two active ingredients, amoxicillin trihydrate and potassium clavulanate, in six different commercial antibiotic type of drugs. Since the quality control process of a drug covers a large number of samples, the scope of this study was also to found the most rapid and low cost sample preparation needed to analyze these drugs with a good precision. The chosen drugs were analyzed in their tablets' "as received" form, in pellets made from the powder of the tablets and also in pellets made from the powder of the tablets after being heated up to 70 °C to avoid any molecular destruction until constant weight and removal of humidity. The quantification validity related to the aspects of each sample preparation (homogeneity of the drug components and humidity) are presented and discussed.

Non-invasive quantitative micro-PIXE-RBS/EBS/EBS imaging reveals the lost polychromy and gilding of the Neo-Assyrian ivories from the Louvre collection.

PubMed

Albéric, Marie; Müller, Katharina; Pichon, Laurent; Lemasson, Quentin; Moignard, Brice; Pacheco, Claire; Fontan, Elisabeth; Reiche, Ina

2015-05-01

Antique objects are known to have been brightly colored. However, the appearance of these objects has changed over time and paint traces are rarely preserved. The surface of ivory objects (8th century B.C., Syria) from the Louvre museum collection (Paris) have been non-invasively studied by simultaneous particle-induced X-ray emission (PIXE) and Rutherford and elastic backscattering spectrometry (RBS/EBS) micro-imaging at the AGLAE facility (C2RMF, Paris). Qualitative 2D chemical images of elements ranging from Na to Pb on the surface of the ancient ivory carvings provide evidence of lost polychromy and gilding. Quantitative PIXE data of specific areas allow discrimination between traces of sediments and former polychromy. Different shades of blue can be differentiated from particular Pb/Cu ratios. The characterization of gilding based on RBS data demonstrates the exceptional technological skills of the Phoenician craftsmen supposed to have carved the Arslan Tash ivories. More precise reconstructions of the original polychromy compared to previous studies and a criterion for the authentication of ancient gilded ivory object are proposed. Copyright © 2015 Elsevier B.V. All rights reserved.

Next generation phage display by use of pVII and pIX as display scaffolds.

PubMed

Løset, Geir Åge; Sandlie, Inger

2012-09-01

Phage display technology has evolved to become an extremely versatile and powerful platform for protein engineering. The robustness of the phage particle, its ease of handling and its ability to tolerate a range of different capsid fusions are key features that explain the dominance of phage display in combinatorial engineering. Implementation of new technology is likely to ensure the continuation of its success, but has also revealed important short comings inherent to current phage display systems. This is in particular related to the biology of the two most popular display capsids, namely pIII and pVIII. Recent findings using two alternative capsids, pVII and pIX, located to the phage tip opposite that of pIII, suggest how they may be exploited to alleviate or circumvent many of these short comings. This review addresses important aspects of the current phage display standard and then discusses the use of pVII and pIX. These may both complement current systems and be used as alternative scaffolds for display and selection to further improve phage display as the ultimate combinatorial engineering platform. Copyright © 2012 Elsevier Inc. All rights reserved.

Characterisation of zinc in slags originated from a contaminated sediment by coupling /μ-PIXE, /μ-RBS, /μ-EXAFS and powder EXAFS spectroscopy

NASA Astrophysics Data System (ADS)

Isaure, M. P.; Laboudigue, A.; Manceau, A.; Sarret, G.; Tiffreau, C.; Trocellier, P.

2001-07-01

Depositing dredged sediments on soils is usual but it is a hazardous practice for the local environment when these sediments are polluted by heavy metals. This chemical hazard can be assessed by determining the speciation of metals. In this study, slags highly polluted with Zn and originated from a contaminated dredged sediment were investigated. Zn speciation was studied by laterally resolved techniques such as μ-particle induced X-ray emission (μ-PIXE), μ-Rutherford backscattering spectrometry (μ-RBS), μ-extended X-ray absorption fine structure (μ-EXAFS), and bulk analyses such as powder EXAFS spectroscopy. μ-PIXE and μ-RBS results showed that high concentrations of Zn were associated with S in localised areas at the surface of the slags while moderate amounts of Zn were mainly associated with Fe in the matrix. EXAFS results allowed to identify ZnS and Zn sorbed on ferrihydrite (5Fe 2O 3·9H 2O), proxy for iron oxy-hydroxides, as the main Zn-bearing phases. The occurrence of this Zn-iron oxy-hydroxide is interpreted as a mobilisation of Zn released from ZnS oxidation.

Particle Induced X-Ray Emission experiment using the K150 3.6 MeV proton beam at TAMU Cyclotron Institute

NASA Astrophysics Data System (ADS)

Pajouhafsar, Yasmin; Alis Manso Rodriguez Team; Sherry Yennello Team

2017-09-01

Particle Induced X-Ray Emission (PIXE) is a non-destructive analytical technique that is used for various tasks, such as elemental composition. The x-rays are emitted when electrons transition from higher to lower energy levels, causing vacancies in the atom's electron configuration. The overall goals of this research are to successfully set up a PIXE experiment and to obtain elemental concentrations for various samples, using the K150 proton beam in the Cyclotron Institute at Texas A&M University. The x-rays produced are unique to each element and analyzed with reference to their known energies. The setup consists of 3 different detectors, providing a wide range of energies: XR-100T CdTe γ/X-Ray, XR-100T/CR Si and XR-100SDD. Accelerating 3.6 MeV protons from the K150 and using PIXE, we determine concentrations from the NaCl samples provided by the Chemical Engineering Department. The concentrations for each element found in the NaCl thin films are obtained and analyzed through the software, GUPIXWIN. DOE Grant (DE-FG02-93ER40773) and Welch Foundation (A-1266).

Lasers in the in-vitro fertilization laboratory

NASA Astrophysics Data System (ADS)

Tadir, Yona; Neev, Joseph; Berns, Michael W.

1993-05-01

Laser beams are routinely used in the clinical practice of assisted reproduction. The main applications are in laparoscopic and hysteroscopic surgery. The potential applications of laser microbeams as a tool for gamete manipulations are studied and basic concepts are discussed.

WE-EF-BRA-09: Microbeam Radiation Therapy Enhances Tumor Drug Uptake of PEGylated Liposomal Doxorubicin (PLD) in a Triple Negative Breast Cancer GEM Model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chang, SX; Madden, AJ; Rivera, JN

Purpose: Overcoming low anti-cancer drug uptake in tumors is a key challenge limiting its clinical use. We propose to enhance the drug delivery using upfront Microbeam Radiation Therapy (MRT). MRT is a preclinical cancer therapy that utilizes microplanar beams to deliver spatially oscillating planes of high and low doses. Animal studies have demonstrated that ultrahigh dose (100s Gy) MRT eradicates tumors without damaging the function of normal tissue exposed to the same radiation. Our previous study indicated that MRT induces intense angiogenesis in tumor rim and surrounding normal tissue 1–2 days post radiation. We hypothesize that the tumor microenvironment modulationmore » induced by MRT may enhance carrier-mediated agent drug delivery to tumors with inherent poor drug uptake. We thus investigated MRT-induced pharmacokinetics (PK) of PEGylated liposomal doxorubicin (PLD), a nano-scale doxorubicin, in T11 genetically engineered mouse model of triple negative breast cancer. Methods: A research irradiator (160kVp, RadSource Technologies) with a customized collimator was used to produce the MRT microbeam of in average 390µm width and 1190µm peak-to-peak distance. The peak dose rate of 1–2Gy/min. Dosimetry is by EBT3 film cross-calibrated with ion chamber at large fields. All mice were administered PLD at 6mg/kg IV x1 at 16h post MRT and sacrificed at 5min, 6h, 24h, and 96h post PLD administration (n=3 or 4 per group). Results: The MRT(28Gy)+PLD group mice had a total doxorubicin tumor concentration (area-under-the concentration-curve, AUC) of 206,040ng/mL•h, 3.71 times the concentration of the PLD-alone group. The MRT(34Gy)+PLD group had a higher mean total doxorubicin concentration in tumor (20,779ng/ml) than the MRT(28Gy)+PLD group (10,665ng/ml). Conclusion: Our preliminary results indicate that microbeam radiation therapy (MRT) can enhance nano-scale anti-cancer drug delivery to tumors approximately 4-fold. The exact working mechanism, the comparison with broad beam irradiation, and optimization of MRT for drug delivery enhancement are under investigation.« less

Neurocognitive sparing of desktop microbeam irradiation.

PubMed

Bazyar, Soha; Inscoe, Christina R; Benefield, Thad; Zhang, Lei; Lu, Jianping; Zhou, Otto; Lee, Yueh Z

2017-08-11

Normal tissue toxicity is the dose-limiting side effect of radiotherapy. Spatial fractionation irradiation techniques, like microbeam radiotherapy (MRT), have shown promising results in sparing the normal brain tissue. Most MRT studies have been conducted at synchrotron facilities. With the aim to make this promising treatment more available, we have built the first desktop image-guided MRT device based on carbon nanotube x-ray technology. In the current study, our purpose was to evaluate the effects of MRT on the rodent normal brain tissue using our device and compare it with the effect of the integrated equivalent homogenous dose. Twenty-four, 8-week-old male C57BL/6 J mice were randomly assigned to three groups: MRT, broad-beam (BB) and sham. The hippocampal region was irradiated with two parallel microbeams in the MRT group (beam width = 300 μm, center-to-center = 900 μm, 160 kVp). The BB group received the equivalent integral dose in the same area of their brain. Rotarod, marble burying and open-field activity tests were done pre- and every month post-irradiation up until 8 months to evaluate the cognitive changes and potential irradiation side effects on normal brain tissue. The open-field activity test was substituted by Barnes maze test at 8th month. A multilevel model, random coefficients approach was used to evaluate the longitudinal and temporal differences among treatment groups. We found significant differences between BB group as compared to the microbeam-treated and sham mice in the number of buried marble and duration of the locomotion around the open-field arena than shams. Barnes maze revealed that BB mice had a lower capacity for spatial learning than MRT and shams. Mice in the BB group tend to gain weight at the slower pace than shams. No meaningful differences were found between MRT and sham up until 8-month follow-up using our measurements. Applying MRT with our newly developed prototype compact CNT-based image-guided MRT system utilizing the current irradiation protocol can better preserve the integrity of normal brain tissue. Consequently, it enables applying higher irradiation dose that promises better tumor control. Further studies are required to evaluate the full extent effects of this novel modality.

In-air RBS measurements at the LAMFI external beam setup

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, T. F.; Added, N.; Moro, M. V.

2014-11-11

This work describes new developments in the external beam setup of the Laboratory of Material Analysis with Ion Beams of the University of São Paulo (LAMFI-USP). This setup was designed to be a versatile analytical station to analyze a broad range of samples. In recent developments, we seek the external beam Rutherford Backscattering Spectroscopy (RBS) analysis to complement the Particle Induced X-ray Emission (PIXE) measurements. This work presents the initial results of the external beam RBS analysis as well as recent developments to improve the energy resolution RBS measurements, in particular tests to seek for sources of resolution degradation. Thesemore » aspects are discussed and preliminary results of in-air RBS analysis of some test samples are presented.« less

Bystander signaling in C. elegans: proton microbeam studies

PubMed Central

Nelson, Gregory; Jones, Tamako; Ortloff, Leticia; Ford, John; Nuñez, Delia; Braby, Leslie

2014-01-01

Biological model: In this project, we investigated the control of radiation-induced genotoxic damage expression in somatic cells of the nematode Caenorhabditis elegans. We measured genotoxic damage in the C. elegans intestine by irradiating young larvae with 20 intestinal cells. Fourteen of these cells undergo exactly one nuclear division without cytoplasmic division leading to 14 binucleate cells. This nuclear division is synchronized and occurs at the first larval molt. Irradiation induces chromosome aberrations including dicentrics which we can quantify as stable anaphase bridges in the binucleate cells of young adult intestines. The endpoint is dose- and LET-dependent and we have demonstrated that individual intestinal cells have unique radiosensitivities. Results: The project has two components, a genetic screen for genes that control cell sensitivity and a microbeam component to directly probe individual cells. The genetic screen has identified several genes in NHEJ repair and telomere metabolism that modulate overall bridge frequency. Knockout mutants of cku-70, cku-80 and lig-4 greatly sensitize animals for anaphase bridge induction. A statistical method was used to determine whether induction of bridges was strictly random and cell autonomous and we determined that expression of bridges in pairs of cells was, in fact, non-random which suggested that signaling between cells affected the pattern of bridge expression. This allowed us to conduct an RNAi and mutation screen for genes that control the signaling (block non-random distributions) and several candidates have been identified. To directly test the notion that signaling of genotoxic damage occurs, we conducted experiments with alpha particles collimated through slits in metal foils and showed that genotoxic damage could be expressed many cell diameters away from a partial body exposure site. Thus, an in vivo bystander effect was demonstrated. Dose targeting was then improved to small regional exposures and eventually to individual cell targeting using 2 MeV protons from the microbeam facility at Texas A&M University. We now employ a green fluorescent protein (GFP)-expressing transgenic worm (rrIs1[elt-2::GFP]) to target GFP-positive gut cells via the gut-specific transcription factor elt-2. This allows alignment of the cell of interest over the microbeam aperture under appropriate fluorescence illumination. Microbeam irradiation experiments for many pairwise combinations of cell signal transmission and reception (observed as expression of anaphase bridges) have been conducted and several interesting patterns emerge. (i) The signaling pattern is cell-specific and does not simply reflect cell–cell distance or require direct contact between cell pairs. (ii) The signal range can be as far as from cell pair 2 to cell pair 8 (>100 µm). (iii) There appears to be a functional compartment boundary at the pharynx/intestine valve as even high-dose exposures to the posterior pharyngeal bulb fail to induce bridges in nearby intestinal cells. (iv) The frequency of signal transmission and reception corresponds broadly to the overall frequency of bridges observed during whole-body irradiations which suggests that direct irradiation and ‘out-of-field’ effects may be additive. These patterns have been analyzed in terms of a cellular logic circuit map for signal transmission and reception. A dose–response for a subset of microbeam-targeted cells was measured over the range of 5–20 Gy. Controlled cell pair targeting was used to test the potential additivity of signals and we found that effects were supra-additive. Finally, preliminary measurements were conducted on GFP-expressing transgenic strains that bore cku-70(tm1524) III and smk-1(mn156) V mutations which confer enhanced radiosensitivity. Cku-70 is a Ku-70 ortholog while smk-1 is orthologous to the mammalian and Dictyostelium discoideum SMEK (suppressor of MEK null) protein. In the cku-70(0/0) strain, the severity of the bridges in bystander cells was enhanced, suggesting that signal recipient cells employ NHEJ repair pathways in the expression of anaphase bridges. Clinical trial registration number: Not applicable.

Time resolved aerosol monitoring in the urban centre of Soweto

NASA Astrophysics Data System (ADS)

Formenti, P.; Annegarn, H. J.; Piketh, S. J.

1998-03-01

A programme of aerosol sampling was conducted from 1982 to 1984 in the urban area of Soweto, Johannesburg, South Africa. The particulate matter (aerodynamic diameter <15 μm) was collected using a two hours time resolution single stage streaker sampler and elemental concentrations were resolved via Particle Induced X-ray Emission (PIXE) analysis. Samples have been selected for analysis from an aerosol sample archive to establish base-line atmospheric conditions that existed in Soweto prior to large scale electrification, and to establish source apportionment of crustal elements between coal smoke and traffic induced road dust, based on chemical elemental measurements. A novel technique is demonstrated for processing PIXE-derived time sequence elemental concentration vectors. Slowly varying background components have been extracted from sulphur and crustal aerosol components, using alternatively two digital filters: a moving minimum, and a moving average. The residuals of the crustal elements, assigned to locally generated aerosol components, were modelled using surrogate tracers: sulphur as a surrogate for coal smoke; and Pb as a surrogate for traffic activity. Results from this source apportionment revealed coal emissions contributed between 40% and 50% of the aerosol mineral matter, while 18-22% originated from road dust. Background aerosol, characteristic of the regional winter aerosol burden over the South African Highveld, was between 12% and 21%. Minor contributors identified included a manganese smelter, located 30 km from the sampling site, and informal trash burning, as the source of intermittent heavy metals (Cu, Zn). Elemental source profiles derived for these various sources are presented.

Identification and quantitive analysis of calcium phosphate microparticles in intestinal tissue by nuclear microscopy

NASA Astrophysics Data System (ADS)

Gomez-Morilla, Inmaculada; Thoree, Vinay; Powell, Jonathan J.; Kirkby, Karen J.; Grime, Geoffrey W.

2006-08-01

Microscopic particles (0.5-2 μm diameter), rich in calcium and phosphorus, are found in the lumen of the mid-distal gut of all mammals investigated, including humans, and these may play a role in immuno-surveillance and immune regulation of antigens from food and symbiotic bacteria that are contained in the gut. Whether these particles can cross in to tissue of the intestinal mucosa is unclear. If so, characterising their morphology and chemical composition is an important task in elucidating their function. The analysis of calcium phosphate in biological tissues has been approached in several ways including optical microscopy, scanning electron microscopy and, most recently in this work, with nuclear microscopy. In this paper, we describe the use of microPIXE and microRBS to locate these particles and to determine, accurately, the ratio of phosphorus to calcium using the information on sample thickness obtained from RBS to allow the PIXE ratios to be corrected. A commercial sample of hydroxy apatite was used to demonstrate accuracy and precision of the technique. Then, in a pilot study on intestinal tissue of mice, we demonstrated the presence of calcium phosphate microparticles, consistent with confocal microscopy observations, and we identified the average molar P:Ca molar ratio as 1.0. Further work will confirm the exact chemical speciation of these particles and will examine the influence of differing calcium containing diets on the formation of these microparticles.

Characterization of inertial confinement fusion (ICF) targets using PIXE, RBS, and STIM analysis.

PubMed

Li, Yongqiang; Liu, Xue; Li, Xinyi; Liu, Yiyang; Zheng, Yi; Wang, Min; Shen, Hao

2013-08-01

Quality control of the inertial confinement fusion (ICF) target in the laser fusion program is vital to ensure that energy deposition from the lasers results in uniform compression and minimization of Rayleigh-Taylor instabilities. The technique of nuclear microscopy with ion beam analysis is a powerful method to provide characterization of ICF targets. Distribution of elements, depth profile, and density image of ICF targets can be identified by particle-induced X-ray emission, Rutherford backscattering spectrometry, and scanning transmission ion microscopy. We present examples of ICF target characterization by nuclear microscopy at Fudan University in order to demonstrate their potential impact in assessing target fabrication processes.

Checking collagen preservation in archaeological bone by non-destructive studies (Micro-CT and IBA)

NASA Astrophysics Data System (ADS)

Beck, L.; Cuif, J.-P.; Pichon, L.; Vaubaillon, S.; Dambricourt Malassé, A.; Abel, R. L.

2012-02-01

The material to be studied is a piece of human skull discovered (1999) in Pleistocene sediments from the Orsang river (Gujarat state, India). From anatomical view point, this skull is highly composite: modern Homo sapiens characters are associated to undoubtedly more ancient features. Absolute dating by 14C is critical to understand this discovery. Prior to dating measurements, non-destructive studies have been carried out. Micro-CT reconstruction (X-ray microtomography) and Ion Beam Analysis (IBA) have been undertaken to check the structural preservation of the fossil and the collagen preservation. PIXE elemental map was used to select well-preserved bone area. RBS/EBS and NRA were used for light element quantification, in particular C, N and O contents. We also demonstrate that the PIXE-RBS/EBS combination is a effective tool for the whole characterization of archaeological and recent bones by analysing in one experiment both mineral and organic fractions. We have shown that the archaeological bone, a fragment of the potentially oldest modern Indian, is enough preserved for radiocarbon dating. We propose that Elastic Backscattering Spectrometry (EBS) using 3 MeV protons could be a good non destructive alternative to conventional CHN method using Carbon-Hydrogen-Nitrogen analyzer for measuring C and N before 14C dating.

Evaluation and mapping of PM2.5 atmospheric aerosols in Arasia region using PIXE and gravimetric measurements

NASA Astrophysics Data System (ADS)

Roumie, M.; Chiari, M.; Srour, A.; Sa'adeh, H.; Reslan, A.; Sultan, M.; Ahmad, M.; Calzolai, G.; Nava, S.; Zubaidi, Th.; Rihawy, M. S.; Hussein, T.; Arafah, D.-E.; Karydas, A. G.; Simon, A.; Nsouli, B.

2016-03-01

The present work is a part of a scientific study conducted among several Arab countries in west Asia, under an International Atomic Energy Agency (IAEA) regional technical cooperation project for Arasia region. The project aims at producing for the first time a database of particulate matter (PM) elemental concentrations in the region that will help in future air quality studies in order to identify commonalities and differences in the presence and contribution of fingerprint pollution sources among the Arasia Member States. The first regional campaign was launched simultaneously in Lebanon, Iraq, Jordan, Syria and United Arab Emirates, using a harmonized sampling and analysis protocol of PM10 and PM2.5 samples. Different samples, collected between October 2014 and February 2015, from the participating countries, were analyzed by PIXE technique and gravimetric measurements were also carried out. The first results of the study will be discussed in a regional perspective. Our study shows that concentrations of fine aerosol fractions are often exceeding the WHO standard values as well as showing some disparities in the obtained values between the different sampling sites. However, some trend similarities of variations with time could also be observed, suggesting a common influence by trans-boundary or external sources of air pollution.

PIXE Analysis of Metal Hull Bolts From HMB DeBraak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Correll, Francis D.; Cole, Lord K.; Slater, Charles J.

2009-03-10

HMB DeBraak was a 16-gun British brig-sloop that sank in a squall on May 25, 1798 off Cape Henlopen, Delaware. Silt covered the wooden hull shortly after it sank, preserving it until DeBraak was raised in 1986. The items recovered from the ship include metal bolts that held the hull together. We used PIXE to measure the compositions of 45 of the bolts and found that they are nearly pure copper (98.3% on average), with most also containing small amounts of iron (0.87%), nickel (0.039%), arsenic (0.43%), silver (0.089%), lead (0.18%), and bismuth (0.12%). A few contain a little indium,more » tin, or antimony, but none contain zinc above the quantization level. The compositions are similar to those reported for 18th-century English copper, but different from several copper alloys also used to make hull bolts. We conclude that, when DeBraak was last fitted out in 1795-1797, the Royal Navy was still using bolts similar to William Forbes's mechanically hardened pure copper bolts. Forbes's process represents the successful innovation and application of new technology in Royal Navy ships during the wars of the late 18th century.« less

In-pixel conversion with a 10 bit SAR ADC for next generation X-ray FELs

NASA Astrophysics Data System (ADS)

Lodola, L.; Batignani, G.; Benkechkache, M. A.; Bettarini, S.; Casarosa, G.; Comotti, D.; Dalla Betta, G. F.; Fabris, L.; Forti, F.; Grassi, M.; Latreche, S.; Malcovati, P.; Manghisoni, M.; Mendicino, R.; Morsani, F.; Paladino, A.; Pancheri, L.; Paoloni, E.; Ratti, L.; Re, V.; Rizzo, G.; Traversi, G.; Vacchi, C.; Verzellesi, G.; Xu, H.

2016-07-01

This work presents the design of an interleaved Successive Approximation Register (SAR) ADC, part of the readout channel for the PixFEL detector. The PixFEL project aims at substantially advancing the state-of-the-art in the field of 2D X-ray imaging for applications at the next generation Free Electron Laser (FEL) facilities. For this purpose, the collaboration is developing the fundamental microelectronic building blocks for the readout channel. This work focuses on the design of the ADC carried out in a 65 nm CMOS technology. To obtain a good tradeoff between power consumption, conversion speed and area occupation, an interleaved SAR ADC architecture was adopted.

VizieR Online Data Catalog: New companions to nearby low-mass stars (Jodar+, 2013)

NASA Astrophysics Data System (ADS)

Jodar, E.; Perez-Garrido, A.; Diaz-Sanchez, A.; Villo, I.; Rebolo, R.; Perez-Prieto, J. A.

2016-04-01

we present the results of a high-resolution imaging survey of 451 late K and M dwarfs selected from the Gliese catalogue (Gliese 1969; Gliese & Jahreiss 1979, 1991, Cat. V/70). The observations were carried out during 2008 using Astralux at the 2.2m telescope at the Centro Astronomico Hispano Aleman (CAHA, Almeria, Spain) and FastCam at the 1.5m Carlos Sanchez Telescope at Teide Observatory (OT, Tenerife, Spain). The observations were done in the Sloan Digital Sky Survey (SDSS) i band at CAHA with pixel scales of ~47mas/pix and the Johnson-Cousin I band at OT with ~43mas/pix. (3 data files).

Heavy metals concentrations in scalp hairs of ASGM miners and inhabitants of the Gorontalo Utara regency

NASA Astrophysics Data System (ADS)

Indriati Arifin, Yayu; Sakakibara, Masayuki; Sera, Koichiro

2017-06-01

We performed the Particle Induced X-ray Emission (PIXE) analysis on scalp hair samples of 115 ASGM miners and inhabitants of Gorontalo Utara regency. Along with mercury (Hg), we presented other trace elements such as Copper (Cu) and Manganese (Mn). Concentrations of Cu, Mn and Hg in the scalp hairs of ASGM miners are higher non miners. Significant and positive correlations coefficients between Cu and Hg concentration with Mn concentration may indicate that there are still unknown metabolism process related with ASGM activities.

Synchrotron X-ray microbeam dosimetry with a 20 micrometre resolution scintillator fibre-optic dosimeter.

PubMed

Archer, James; Li, Enbang; Petasecca, Marco; Stevenson, Andrew; Livingstone, Jayde; Dipuglia, Andrew; Davis, Jeremy; Rosenfeld, Anatoly; Lerch, Michael

2018-05-01

Cancer is one of the leading causes of death worldwide. External beam radiation therapy is one of the most important modalities for the treatment of cancers. Synchrotron microbeam radiation therapy (MRT) is a novel pre-clinical therapy that uses highly spatially fractionated X-ray beams to target tumours, allowing doses much higher than conventional radiotherapies to be delivered. A dosimeter with a high spatial resolution is required to provide the appropriate quality assurance for MRT. This work presents a plastic scintillator fibre optic dosimeter with a one-dimensional spatial resolution of 20 µm, an improvement on the dosimeter with a resolution of 50 µm that was demonstrated in previous work. The ability of this probe to resolve microbeams of width 50 µm has been demonstrated. The major limitations of this method were identified, most notably the low-light signal resulting from the small sensitive volume, which made valley dose measurements very challenging. A titanium-based reflective paint was used as a coating on the probe to improve the light collection, but a possible effect of the high-Z material on the probes water-equivalence has been identified. The effect of the reflective paint was a 28.5 ± 4.6% increase in the total light collected; it did not affect the shape of the depth-dose profile, nor did it explain an over-response observed when used to probe at low depths, when compared with an ionization chamber. With improvements to the data acquisition, this probe design has the potential to provide a water-equivalent, inexpensive dosimetry tool for MRT.