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.

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.

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.

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.

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.

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.

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.

Functional group diversity is key to Southern Ocean benthic carbon pathways

PubMed Central

Sands, Chester J.

2017-01-01

High latitude benthos are globally important in terms of accumulation and storage of ocean carbon, and the feedback this is likely to have on regional warming. Understanding this ecosystem service is important but difficult because of complex taxonomic diversity, history and geography of benthic biomass. Using South Georgia as a model location (where the history and geography of benthic biology is relatively well studied) we investigated whether the composition of functional groups were critical to benthic accumulation, immobilization and burial pathway to sequestration–and also aid their study through simplification of identification. We reclassified [1], [2]) morphotype and carbon mass data to 13 functional groups, for each sample of 32 sites around the South Georgia continental shelf. We investigated the influence on carbon accumulation, immobilization and sequestration estimate by multiple factors including the compositions of functional groups. Functional groups showed high diversity within and between sites, and within and between habitat types. Carbon storage was not linked to a functional group in particular but accumulation and immobilization increased with the number of functional groups present and the presence of hard substrata. Functional groups were also important to carbon burial rate, which increased with the presence of mixed (hard and soft substrata). Functional groups showed high surrogacy for taxonomic composition and were useful for examining contrasting habitat categorization. Functional groups not only aid marine carbon storage investigation by reducing time and the need for team size and speciality, but also important to benthic carbon pathways per se. There is a distinct geography to seabed carbon storage; seabed boulder-fields are hotspots of carbon accumulation and immobilization, whilst the interface between such boulder-fields and sediments are key places for burial and sequestration. PMID:28654664

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

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.

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.

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.

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.

Development of a novel remote‐controlled and self‐contained audiovisual‐aided interactive system for immobilizing claustrophobic patients

PubMed Central

Ju, Harang; Kim, Siyong; Read, Paul; Trifiletti, Daniel; Harrell, Andrew; Libby, Bruce

2015-01-01

In radiotherapy, only a few immobilization systems, such as open‐face mask and head mold with a bite plate, are available for claustrophobic patients with a certain degree of discomfort. The purpose of this study was to develop a remote‐controlled and self‐contained audiovisual (AV)‐aided interactive system with the iPad mini with Retina display for intrafractional motion management in brain/H&N (head and neck) radiotherapy for claustrophobic patients. The self‐contained, AV‐aided interactive system utilized two tablet computers: one for AV‐aided interactive guidance for the subject and the other for remote control by an operator. The tablet for audiovisual guidance traced the motion of a colored marker using the built‐in front‐facing camera, and the remote control tablet at the control room used infrastructure Wi‐Fi networks for real‐time communication with the other tablet. In the evaluation, a programmed QUASAR motion phantom was used to test the temporal and positional accuracy and resolution. Position data were also obtained from ten healthy volunteers with and without guidance to evaluate the reduction of intrafractional head motion in simulations of a claustrophobic brain or H&N case. In the phantom study, the temporal and positional resolution was 24 Hz and 0.2 mm. In the volunteer study, the average superior–inferior and right–left displacement was reduced from 1.9 mm to 0.3 mm and from 2.2 mm to 0.2 mm with AV‐aided interactive guidance, respectively. The superior–inferior and right–left positional drift was reduced from 0.5 mm/min to 0.1 mm/min and from 0.4 mm/min to 0.04 mm/min with audiovisual‐aided interactive guidance. This study demonstrated a reduction in intrafractional head motion using a remote‐controlled and self‐contained AV‐aided interactive system of iPad minis with Retina display, easily obtainable and cost‐effective tablet computers. This approach can potentially streamline clinical flow for claustrophobic patients without a head mask and also allows patients to practice self‐motion management before radiation treatment delivery. PACS number: 87.55.Gh

Enzyme nanoparticle fabrication: magnetic nanoparticle synthesis and enzyme immobilization.

PubMed

Johnson, Patrick A; Park, Hee Joon; Driscoll, Ashley J

2011-01-01

Immobilized enzymes are drawing significant attention for potential commercial applications as biocatalysts by reducing operational expenses and by increasing process utilization of the enzymes. Typically, immobilized enzymes have greater thermal and operational stability at various pH values, ionic strengths and are more resistant to denaturation that the soluble native form of the enzyme. Also, immobilized enzymes can be recycled by utilizing the physical or chemical properties of the supporting material. Magnetic nanoparticles provide advantages as the supporting material for immobilized enzymes over competing materials such as: higher surface area that allows for greater enzyme loading, lower mass transfer resistance, less fouling effect, and selective, nonchemical separation from the reaction mixture by an applied a magnetic field. Various surface modifications of magnetic nanoparticles, such as silanization, carbodiimide activation, and PEG or PVA spacing, aid in the binding of single or multienzyme systems to the particles, while cross-linking using glutaraldehyde can also stabilize the attached enzymes.

Titanium Immobilized with an Antimicrobial Peptide Derived from Histatin Accelerates the Differentiation of Osteoblastic Cell Line, MC3T3-E1

PubMed Central

Makihira, Seicho; Shuto, Takahiro; Nikawa, Hiroki; Okamoto, Keishi; Mine, Yuichi; Takamoto, Yuko; Ohara, Masaru; Tsuji, Koichiro

2010-01-01

The objective of this study was to evaluate the effect of titanium immobilized with a cationic antimicrobial peptide (JH8194) derived from histatin on the biofilm formation of Porphyromonas gingivalis and differentiation of osteoblastic cells (MC3T3-E1). The titanium specimens (Ti) were immobilized with JH8194, according to the method previously described. The colonization of P. gingivalis on JH8194-Ti was significantly lower than that on control- and blocking-Ti. JH8194-Ti enhanced the mRNA expressions of Runx2 and OPN, and ALPase activity in the MC3T3-E1, as compared with those of control- and blocking-Ti. These results, taken together, suggested the possibility that JH8194-Ti may be a potential aid to shorten the period of acquiring osseointegration. PMID:20480030

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).

Acetylcholinesterase immobilization and characterization, and comparison of the activity of the porous silicon-immobilized enzyme with its free counterpart.

PubMed

Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

2016-02-02

A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4-9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness. © 2016 Authors.

Acetylcholinesterase immobilization and characterization, and comparison of the activity of the porous silicon-immobilized enzyme with its free counterpart

PubMed Central

Saleem, Muhammad; Rafiq, Muhammad; Seo, Sung-Yum; Lee, Ki Hwan

2016-01-01

A successful prescription is presented for acetylcholinesterase physically adsorbed on to a mesoporous silicon surface, with a promising hydrolytic response towards acetylthiocholine iodide. The catalytic behaviour of the immobilized enzyme was assessed by spectrophotometric bioassay using neostigmine methyl sulfate as a standard acetycholinesterase inhibitor. The surface modification was studied through field emission SEM, Fourier transform IR spectroscopy, energy-dispersive X-ray spectroscopy, cathode luminescence and X-ray photoelectron spectroscopy analysis, photoluminescence measurement and spectrophotometric bioassay. The porous silicon-immobilized enzyme not only yielded greater enzyme stability, but also significantly improved the native photoluminescence at room temperature of the bare porous silicon architecture. The results indicated the promising catalytic behaviour of immobilized enzyme compared with that of its free counterpart, with a greater stability, and that it aided reusability and easy separation from the reaction mixture. The porous silicon-immobilized enzyme was found to retain 50% of its activity, promising thermal stability up to 90°C, reusability for up to three cycles, pH stability over a broad pH of 4–9 and a shelf-life of 44 days, with an optimal hydrolytic response towards acetylthiocholine iodide at variable drug concentrations. On the basis of these findings, it was believed that the porous silicon-immobilized enzyme could be exploited as a reusable biocatalyst and for screening of acetylcholinesterase inhibitors from crude plant extracts and synthesized organic compounds. Moreover, the immobilized enzyme could offer a great deal as a viable biocatalyst in bioprocessing for the chemical and pharmaceutical industries, and bioremediation to enhance productivity and robustness. PMID:26839417

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.

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.

Usewear studies of flint tools with microPIXE and microRBS

NASA Astrophysics Data System (ADS)

Christensen, Marianne; Grime, Geoff; Menu, Michel; Walter, Philippe

1993-05-01

The use of ancient stone tools leaves a polish (usewear) on the cutting edge which can be studied to determine the material the tool had worked during its use. The film is formed by high pressure intrusion of the worked material into the microcavities of the chipped flint surface and so the film can also be analysed directly to determine the nature of the worked material. This paper describes the analysis of experimental flint tools which had worked bone and ivory using microbeam PIXE and RBS. It is found that PIXE used simultaneously with RBS allows the thickness and composition of the film to be determined and ivory distinguished from bone while RBS mapping allows the three-dimensional structure of the film to be determined.

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.

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.

Light transfer in agar immobilized microalgae cell cultures

NASA Astrophysics Data System (ADS)

Kandilian, Razmig; Jesus, Bruno; Legrand, Jack; Pilon, Laurent; Pruvost, Jérémy

2017-09-01

This paper experimentally and theoretically investigates light transfer in agar-immobilized cell cultures. Certain biotechnological applications such as production of metabolites secreted by photosynthetic microorganisms require cells to be immobilized in biopolymers to minimize contamination and to facilitate metabolite recovery. In such applications, light absorption by cells is one of the most important parameters affecting cell growth or metabolite productivity. Modeling light transfer therein can aid design and optimize immobilized-cell reactors. In this study, Parachlorella kessleri cells with areal biomass concentrations ranging from 0.36 to 16.9 g/m2 were immobilized in 2.6 mm thick agar gels. The average absorption and scattering cross-sections as well as the scattering phase function of P. kessleri cells were measured. Then, the absorption and transport scattering coefficients of the agar gel were determined using an inverse method based on the modified two-flux approximation. The forward model was used to predict the normal-hemispherical transmittance and reflectance of the immobilized-cell films accounting for absorption and scattering by both microalgae and the agar gel. Good agreement was found between the measured and predicted normal-hemispherical transmittance and reflectance provided absorption and scattering by agar were taken into account. Moreover, good agreement was found between experimentally measured and predicted mean rate of photon absorption. Finally, optimal areal biomass concentration was determined to achieve complete absorption of the incident radiation.

Effects of two educational method of lecturing and role playing on knowledge and performance of high school students in first aid at emergency scene

PubMed Central

Hassanzadeh, Akbar; Vasili, Arezu; Zare, Zahra

2010-01-01

BACKGROUND: This study aimed to investigate the effects of two educational methods on students' knowledge and performance regarding first aid at emergency scenes. METHODS: In this semi-experimental study, the sample was selected randomly among male and female public high school students of Isfahan. Each group included 60 students. At first the knowledge and performance of students in first aid at emergency scene was assessed using a researcher-made questionnaire. Then necessary education was provided to the students within 10 sessions of two hours by lecturing and role playing. The students' knowledge and performance was as-sessed again and the results were compared. RESULTS: It was no significant relationship between the frequency distribution of students' age, major and knowledge and performance before the educational course in the two groups. The score of knowledge in performing CPR, using proper way to bandage, immobilizing the injured area, and proper ways of carrying injured person after the education was significantly increased in both groups. Moreover, the performance in proper way to bandage, immobilizing injured area and proper ways of carrying injured person after educational course was significantly higher in playing role group compared to lecturing group after education. CONCLUSIONS: Iran is a developing country with a young generation and it is a country with high risk of natural disasters; so, providing necessary education with more effective methods can be effective in reducing mortality and morbidity due to lack of first aid care in crucial moments. Training with playing role is suggested for this purpose. PMID:21589743

Effects of two educational method of lecturing and role playing on knowledge and performance of high school students in first aid at emergency scene.

PubMed

Hassanzadeh, Akbar; Vasili, Arezu; Zare, Zahra

2010-01-01

This study aimed to investigate the effects of two educational methods on students' knowledge and performance regarding first aid at emergency scenes. In this semi-experimental study, the sample was selected randomly among male and female public high school students of Isfahan. Each group included 60 students. At first the knowledge and performance of students in first aid at emergency scene was assessed using a researcher-made questionnaire. Then necessary education was provided to the students within 10 sessions of two hours by lecturing and role playing. The students' knowledge and performance was as-sessed again and the results were compared. It was no significant relationship between the frequency distribution of students' age, major and knowledge and performance before the educational course in the two groups. The score of knowledge in performing CPR, using proper way to bandage, immobilizing the injured area, and proper ways of carrying injured person after the education was significantly increased in both groups. Moreover, the performance in proper way to bandage, immobilizing injured area and proper ways of carrying injured person after educational course was significantly higher in playing role group compared to lecturing group after education. Iran is a developing country with a young generation and it is a country with high risk of natural disasters; so, providing necessary education with more effective methods can be effective in reducing mortality and morbidity due to lack of first aid care in crucial moments. Training with playing role is suggested for this purpose.

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.

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.

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.

Fish gelatin thin film standards for biological application of PIXE

NASA Astrophysics Data System (ADS)

Manuel, Jack E.; Rout, Bibhudutta; Szilasi, Szabolcs Z.; Bohara, Gyanendra; Deaton, James; Luyombya, Henry; Briski, Karen P.; Glass, Gary A.

2014-08-01

There exists a critical need to understand the flow and accumulation of metallic ions, both naturally occurring and those introduced to biological systems. In this paper the results of fabricating thin film elemental biological standards containing nearly any combination of trace elements in a protein matrix are presented. Because it is capable of high elemental sensitivity, particle induced X-ray emission spectrometry (PIXE) is an excellent candidate for in situ analysis of biological tissues. Additionally, the utilization of microbeam PIXE allows the determination of elemental concentrations in and around biological cells. However, obtaining elemental reference standards with the same matrix constituents as brain tissue is difficult. An excellent choice for simulating brain-like tissue is Norland® photoengraving glue which is derived from fish skin. Fish glue is water soluble, liquid at room temperature, and resistant to dilute acid. It can also be formed into a thin membrane which dries into a durable, self-supporting film. Elements of interest are introduced to the fish glue in precise volumetric additions of well quantified atomic absorption standard solutions. In this study GeoPIXE analysis package is used to quantify elements intrinsic to the fish glue as well as trace amounts of manganese added to the sample. Elastic (non-Rutherford) backscattered spectroscopy (EBS) and the 1.734 MeV proton-on-carbon 12C(p,p)12C resonance is used for a normalization scheme of the PIXE spectra to account for any discrepancies in X-ray production arising from thickness variation of the prepared standards. It is demonstrated that greater additions of the atomic absorption standard cause a viscosity reduction of the liquid fish glue resulting in thinner films but the film thickness can be monitored by using simultaneous PIXE and EBS proton data acquisition.

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.

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.

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.

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.

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.

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.

Coprinus comatus Damages Nematode Cuticles Mechanically with Spiny Balls and Produces Potent Toxins To Immobilize Nematodes▿

PubMed Central

Luo, Hong; Liu, Yajun; Fang, Lin; Li, Xuan; Tang, Ninghua; Zhang, Keqin

2007-01-01

We reported recently a unique fungal structure, called the spiny ball, on the vegetative hyphae of Coprinus comatus (O. F. Müll.:Fr.) Pers. Although some observations regarding the role of this structure were presented, its function remained largely unknown. In this study, we showed that purified (isolated and washed) spiny balls could immobilize and kill the free-living nematode Panagrellus redivivus Goodey highly efficiently. Scanning electron microscopy studies illustrated that the spiny structure damaged the nematode cuticle, suggesting the presence of a mechanical force during the process of nematode immobilization. Severe injuries on nematode cuticles caused the leakage of inner materials of the nematodes. When these structures were ground in liquid nitrogen, their killing efficacy against nematodes was lost, indicating that the shape and the complete structure of the spiny balls are indispensable for their function. However, extraction with organic solvents never lowered their activity against P. redivivus, and the extracts showed no obvious effect on the nematode. We also investigated whether C. comatus was able to produce toxins which would aid in the immobilization of nematodes. In total, we identified seven toxins from C. comatus that showed activity to immobilize the nematodes P. redivivus and Meloidogyne incognita (Kofoid et White) Chitwood. The chemical structures of these toxins were identified with nuclear magnetic resonance, mass spectrometry, infrared, and UV spectrum analysis. Two compounds were found to be novel. The toxins found in C. comatus are O-containing heterocyclic compounds. PMID:17449690

Coprinus comatus damages nematode cuticles mechanically with spiny balls and produces potent toxins to immobilize nematodes.

PubMed

Luo, Hong; Liu, Yajun; Fang, Lin; Li, Xuan; Tang, Ninghua; Zhang, Keqin

2007-06-01

We reported recently a unique fungal structure, called the spiny ball, on the vegetative hyphae of Coprinus comatus (O. F. Müll.:Fr.) Pers. Although some observations regarding the role of this structure were presented, its function remained largely unknown. In this study, we showed that purified (isolated and washed) spiny balls could immobilize and kill the free-living nematode Panagrellus redivivus Goodey highly efficiently. Scanning electron microscopy studies illustrated that the spiny structure damaged the nematode cuticle, suggesting the presence of a mechanical force during the process of nematode immobilization. Severe injuries on nematode cuticles caused the leakage of inner materials of the nematodes. When these structures were ground in liquid nitrogen, their killing efficacy against nematodes was lost, indicating that the shape and the complete structure of the spiny balls are indispensable for their function. However, extraction with organic solvents never lowered their activity against P. redivivus, and the extracts showed no obvious effect on the nematode. We also investigated whether C. comatus was able to produce toxins which would aid in the immobilization of nematodes. In total, we identified seven toxins from C. comatus that showed activity to immobilize the nematodes P. redivivus and Meloidogyne incognita (Kofoid et White) Chitwood. The chemical structures of these toxins were identified with nuclear magnetic resonance, mass spectrometry, infrared, and UV spectrum analysis. Two compounds were found to be novel. The toxins found in C. comatus are O-containing heterocyclic compounds.

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.

Micro-PIXE and micro-RBS characterization of micropores in porous silicon prepared using microwave-assisted hydrofluoric acid etching.

PubMed

Ahmad, Muthanna; Grime, Geoffrey W

2013-04-01

Porous silicon (PS) has been prepared using a microwave-assisted hydrofluoric acid (HF) etching method from a silicon wafer pre-implanted with 5 MeV Cu ions. The use of microbeam proton-induced X-ray emission (micro-PIXE) and microbeam Rutherford backscattering techniques reveals for the first time the capability of these techniques for studying the formation of micropores. The porous structures observed from micro-PIXE imaging results are compared to scanning electron microscope images. It was observed that the implanted copper accumulates in the same location as the pores and that at high implanted dose the pores form large-scale patterns of lines and concentric circles. This is the first work demonstrating the use of microwave-assisted HF etching in the formation of PS.

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.

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

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.

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

A novel first aid stretcher for immobilization and transportation of spine injured patients.

PubMed

Liu, Yan-Sheng; Feng, Ya-Ping; Xie, Jia-Xin; Luo, Zhuo-Jing; Shen, Cai-Hong; Niu, Fang; Zou, Jian; Tang, Shao-Feng; Hao, Jiang; Xu, Jia-Xiang; Xiao, Li-Ping; Xu, Xiao-Ming; Zhu, Hui

2012-01-01

Effective immobilization and transportation are vital to the life-saving acute medical care needed when treating critically injured people. However, the most common types of stretchers used today are wrought with problems that can lead to further medical complications, difficulty in employment and rescue, and ineffective transitions to hospital treatment. Here we report a novel first aid stretcher called the "emergency carpet", which solves these problems with a unique design for spine injured patients. Polyurethane composite material, obtained by a novel process of manually mixing isocyanate and additives, can be poured into a specially designed fabric bag and allowed to harden to form a rigid human-shaped stretcher. The effectiveness of the emergency carpet was examined in the pre-hospital management of victims with spinal fractures. Additionally, it was tested on flat ground and complex terrain as well as in the sea and air. We demonstrated that the emergency carpet can be assembled and solidified on the scene in 5 minutes, providing effective immobilization to the entire injured body. With the protection of the emergency carpet, none of the 20 patients, who were finally confirmed to have spinal column fracture or dislocation, had any neurological deterioration during transportation. Furthermore, the carpet can be handled and transported by multiple means under differing conditions, without compromising immobilization. Finally, the emergency carpet allows the critically injured patient to receive multiple examinations such as X-ray, CT, and MRI without being removed from the carpet. Our results demonstrate that the emergency carpet has ideal capabilities for immobilization, extrication, and transportation of the spine injured patients. Compared with other stretchers, it allows for better mobility, effective immobilization, remarkable conformity to the body, and various means for transportation. The emergency carpet is promising for its intrinsic advantages in the pre-hospital management of accident victims.

The Influence of Ambulatory Aid on Lower-Extremity Muscle Activation During Gait.

PubMed

Sanders, Michael; Bowden, Anton E; Baker, Spencer; Jensen, Ryan; Nichols, McKenzie; Seeley, Matthew K

2018-05-10

Foot and ankle injuries are common and often require a nonweight-bearing period of immobilization for the involved leg. This nonweight-bearing period usually results in muscle atrophy for the involved leg. There is a dearth of objective data describing muscle activation for different ambulatory aids that are used during the aforementioned nonweight-bearing period. To compare activation amplitudes for 4 leg muscles during (1) able-bodied gait and (2) ambulation involving 3 different ambulatory aids that can be used during the acute phase of foot and ankle injury care. Within-subject, repeated measures. University biomechanics laboratory. Sixteen able-bodied individuals (7 females and 9 males). Each participant performed able-bodied gait and ambulation using 3 different ambulatory aids (traditional axillary crutches, knee scooter, and a novel lower-leg prosthesis). Muscle activation amplitude quantified via mean surface electromyography amplitude throughout the stance phase of ambulation. Numerous statistical differences (P < .05) existed for muscle activation amplitude between the 4 observed muscles, 3 ambulatory aids, and able-bodied gait. For the involved leg, comparing the 3 ambulatory aids: (1) knee scooter ambulation resulted in the greatest vastus lateralis activation, (2) ambulation using the novel prosthesis and traditional crutches resulted in greater biceps femoris activation than knee scooter ambulation, and (3) ambulation using the novel prosthesis resulted in the greatest gastrocnemius activation (P < .05). Generally speaking, muscle activation amplitudes were most similar to able-bodied gait when subjects were ambulating using the knee scooter or novel prosthesis. Type of ambulatory aid influences muscle activation amplitude. Traditional axillary crutches appear to be less likely to mitigate muscle atrophy during the nonweighting, immobilization period that often follows foot or ankle injuries. Researchers and clinicians should consider these results when recommending ambulatory aids for foot or ankle injuries.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Solution-derived sodalite made with Si- and Ge-ethoxide precursors for immobilizing electrorefiner salt

NASA Astrophysics Data System (ADS)

Riley, Brian J.; Lepry, William C.; Crum, Jarrod V.

2016-01-01

Chlorosodalite has the general form of Na8(AlSiO4)6Cl2 and this paper describes experiments conducted to synthesize sodalite with a solution-based approach to immobilize a simulated spent electrorefiner salt solution containing a mixture of alkali, alkaline earth, and lanthanide chlorides. The reactants used were the salt solution, NaAlO2, and either Si(OC2H5)4 or Ge(OC2H5)4. Additionally, seven different glass sintering aids (at loadings of 5 mass%) were evaluated as sintering aids for consolidating the as-made powders using a cold-press-and-sinter technique. This process of using alkoxide additives for the Group IV component can be used to produce large quantities of sodalite at near-room temperature as compared to a method where colloidal silica was used as the silica source. However, the small particle sizes inhibited densification during heat treatments.

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)".

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.

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

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.

An acetylcholinesterase biosensor based on graphene-gold nanocomposite and calcined layered double hydroxide.

PubMed

Zhai, Chen; Guo, Yemin; Sun, Xia; Zheng, Yuhe; Wang, Xiangyou

2014-05-10

In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu-Mg-Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene-gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene-gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150μg/L. The detection limit for chlorpyrifos was 0.05μg/L. Copyright © 2014 Elsevier Inc. All rights reserved.

Nattokinase: an updated critical review on challenges and perspectives.

PubMed

Selvarajan, Ethiraj; Bhatnagar, Niharika

2017-12-07

Natto, a fermented soybean food, has been consumed by oriental people for more than 1000 years. Nattokinase, formerly called subtilisin NAT is a well studied protease of microbial origin that possesses fibrinolytic (anti-clotting) activities. Due to its strong fibrinolytic and thrombolytic activity, Nattokinase is regarded as a precious dietary supplement or nutraceutical for the oral thrombolytic therapy. Nattokinase is witnessed to be a useful enzyme for the com-plete removal of the vitreous and associated proliferative tissues in proliferative vitreo retinal disorders. This review focuses on the native and recombinant Nattokinase from bacteria and other sources, their production, purification, immobilization and nano-immobilization studies, which aid in ameliorating their properties to suit the targeted industrial applications. Recent development in these fields are presented and discussed, and prospective developments are suggested. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Simultaneous immobilization of metals and arsenic in acidic polluted soils near a copper smelter in central Chile.

PubMed

Cárcamo, Valeska; Bustamante, Elena; Trangolao, Elizabeth; de la Fuente, Luz María; Mench, Michel; Neaman, Alexander; Ginocchio, Rosanna

2012-05-01

Acidic and metal(oid)-rich topsoils resulted after 34 years of continuous operations of a copper smelter in the Puchuncaví valley, central Chile. Currently, large-scale remediation actions for simultaneous in situ immobilization of metals and As are needed to reduce environmental risks of polluted soils. Aided phytostabilization is a cost-effective alternative, but adequate local available soil amendments have to be identified and management options have to be defined. Efficacy of seashell grit (SG), biosolids (B), natural zeolite (Z), and iron-activated zeolite (AZ), either alone or in mixtures, was evaluated for reducing metal (Cu and Zn) and As solubilization in polluted soils under laboratory conditions. Perennial ryegrass was used to test phytotoxicity of experimental substrates. Soil neutralization to a pH of 6.5 with SG, with or without incorporation of AZ, significantly reduces metal (Cu and Zn) solubilization without affecting As solubilization in soil pore water; furthermore, it eliminates phytotoxicity and excessive metal(oid) accumulation in aerial plant tissues. Addition of B or Z to SG-amended soil does not further reduce metal solubilization into soil pore water, but increase As solubilization due to excessive soil neutralization (pH > 6.5); however, no significant As increase occurs in aerial plant tissues. Simultaneous in situ immobilization of metal(oid) in acidic topsoils is possible through aided phytostabilization.

Knowledge levels of pre-school teachers related with basic first-aid practices, Isparta sample.

PubMed

Sönmez, Yonca; Uskun, Ersin; Pehlivan, Azize

2014-09-01

The aim of this study was to evaluate the levels of knowledge of pre-school teachers working in the province center of Isparta related with basic first-aid practices and some factors which affected these levels of knowledge. In this cross-sectional, analytic study, 110 pre-school teachers working in the province center of Isparta constituted the population. A questionnaire questioning sociodemographic properties and the level of knowledge related with first-aid practices was applied under supervision. The level of knowledge was evaluated on a 20-point scale. In the analyses, Kruskal-Wallis and Mann-Whitney U tests and Spearman's rank correlation were used. The study was approved by the Ethical Committee for Clinical Studies of Süleyman Demirel University School of Medicine (registration number: 105). The mean score of first-aid knowledge of the pre-school teachers was found to be 11.9±2.9. The least known issues included washing the wound by soap and water after a dog bite, information related with the necessity of immobilization of a child who has fallen from a high level and the phone number of National Poison Information Center (16.4%, 20.9% and 22.7%, respectively). The scores of the subjects whose knowledge of first-aid was evaluated to be well were higher compared to the subjects whose knowledge of first-aid was evaluated to be moderate (p=0.009) and poor (p=0.001). It was found that first-aid scores did not show significant difference in terms of age, working period, having received first-aid training and having faced with a condition requiring first-aid previously (p>0.05, for all comparisons). It was found that pre-school teachers had insufficient first-aid knowledge. Since the first-aid knowledge scores of the subjects who reported that they received first-aid training before did not show significant difference, it was thought that the quality of training was as important as receiving training.

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.

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 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.

Study of atmospheric aerosols by IBA techniques: The LABEC experience

NASA Astrophysics Data System (ADS)

Lucarelli, F.; Calzolai, G.; Chiari, M.; Nava, S.; Carraresi, L.

2018-02-01

At the 3 MV Tandetron accelerator of the LABEC laboratory of INFN (Florence, Italy) an external beam facility is fully dedicated to PIXE-PIGE measurements of the elemental composition of atmospheric aerosols. All the elements with Z > 10 are simultaneously detected by PIXE typically in one minute. This setup allows us an easy automatic positioning, changing and scanning of samples collected by different kinds of devices: long series of daily PM (Particulate Matter) samples can be analysed in short times, as well as size-segregated and high time-resolution aerosol samples. Thanks to the capability of detecting all the crustal elements, PIXE-PIGE analyses are unrivalled in the study of mineral dust: consequently, they are very effective in the study of natural aerosols, like, for example, Saharan dust intrusions. Among the detectable elements there are also important markers of anthropogenic sources, which allow effective source apportionment studies in polluted urban environments using a multivariate method like Positive Matrix Factorization (PMF). Examples regarding recent monitoring campaigns, performed in urban and remote areas, both daily and with high time resolution (hourly samples), as well as with size selection, are presented. The importance of the combined use of the Particle Induced Gamma Ray emission technique (PIGE) and of other complementary (non-nuclear) techniques is highlighted.

From functional structure to packaging: full-printing fabrication of a microfluidic chip.

PubMed

Zheng, Fengyi; Pu, Zhihua; He, Enqi; Huang, Jiasheng; Yu, Bocheng; Li, Dachao; Li, Zhihong

2018-05-24

This paper presents a concept of a full-printing methodology aiming at convenient and fast fabrication of microfluidic devices. For the first time, we achieved a microfluidic biochemical sensor with all functional structures fabricated by inkjet printing, including electrodes, immobilized enzymes, microfluidic components and packaging. With the cost-effective and rapid process, this method provides the possibility of quick model validation of a novel lab-on-chip system. In this study, a three-electrode electrochemical system was integrated successfully with glucose oxidase immobilization gel and sealed in an ice channel, forming a disposable microfluidic sensor for glucose detection. This fully-printed chip was characterized and showed good sensitivity and a linear section at a low-level concentration of glucose (0-10 mM). With the aid of automatic equipment, the fully-printed sensor can be massively produced with low cost.

Immobilization of LiCl-Li2O pyroprocessing salt wastes in chlorosodalite using glass-bonded hydrothermal and salt-occlusion methods

NASA Astrophysics Data System (ADS)

Riley, Brian J.; Peterson, Jacob A.; Kroll, Jared O.; Frank, Steven M.

2018-04-01

In this study, hydrothermal and salt-occlusion processes were used to make chlorosodalite through reactions with a high-LiCl salt simulating a waste stream generated from pyrochemical treatment of oxide-based used nuclear fuel. Some products were reacted with glass binders to increase chlorosodalite yield through alkali ion exchange and to aid in densification. Hydrothermal processes included reaction of the salt simulant in an autoclave with either zeolite 4A or sodium aluminate and colloidal silica. Chlorosodalite yields in the crystalline products were nearly complete in the glass-bonded materials at values of 100 mass% for the salt-occlusion method, up to 99.0 mass% for the hydrothermal synthesis with zeolite 4A, and up to 96 mass% for the hydrothermal synthesis with sodium aluminate and colloidal silica. These results show promise for using chemically stable chlorosodalite to immobilize oxide reduction salt wastes.

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 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.

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

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...

Direct Electrochemical Addressing of Immobilized Alcohol Dehydrogenase for the Heterogeneous Bioelectrocatalytic Reduction of Butyraldehyde to Butanol.

PubMed

Schlager, S; Neugebauer, H; Haberbauer, M; Hinterberger, G; Sariciftci, N S

2015-03-01

Modified electrodes using immobilized alcohol dehydrogenase enzymes for the efficient electroreduction of butyraldehyde to butanol are presented as an important step for the utilization of CO 2 -reduction products. Alcohol dehydrogenase was immobilized, embedded in an alginate-silicate hybrid gel, on a carbon felt (CF) electrode. The application of this enzyme to the reduction of an aldehyde to an alcohol with the aid of the coenzyme nicotinamide adenine dinucleotide (NADH), in analogy to the final step in the natural reduction cascade of CO 2 to alcohol, has been already reported. However, the use of such enzymatic reductions is limited because of the necessity of providing expensive NADH as a sacrificial electron and proton donor. Immobilization of such dehydrogenase enzymes on electrodes and direct pumping of electrons into the biocatalysts offers an easy and efficient way for the biochemical recycling of CO 2 to valuable chemicals or alternative synthetic fuels. We report the direct electrochemical addressing of immobilized alcohol dehydrogenase for the reduction of butyraldehyde to butanol without consumption of NADH. The selective reduction of butyraldehyde to butanol occurs at room temperature, ambient pressure and neutral pH. Production of butanol was detected by using liquid-injection gas chromatography and was estimated to occur with Faradaic efficiencies of around 40 %.

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.

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.

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.

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.

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.

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.

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";…

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.

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.

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.

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.

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.

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.

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.

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.

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.

Paintings on copper by the Flemish artist Frans Francken II: PIXE characterization by external microbeam

NASA Astrophysics Data System (ADS)

Corregidor, V.; Oliveira, A. R.; Rodrigues, P. A.; Alves, L. C.

2015-04-01

Resorting to an external proton microbeam, PIXE analyses of three oil paintings on copper support dated from the XVII century and attributed to the Flemish artist Frans Francken II, were undertaken. The present work aims to contribute to the compositional study of the painting materials employed by XVII century artists that exploited copper as a support for oil painting, and specifically the materials used by Francken's workshop, particularly copper plates. Because of the low thickness of the pictorial layers of this type of paintings and its non-destructive character, PIXE is the ideal technique to study the elemental composition of the paintings. Several spots in each painting were chosen for analysis in order to cover almost all the pigments used in the colour palette. Lead and calcium were detected in practically every analysed regions, probably related to the presence of lead white and chalk, usually used as ground layer on copper paintings. Small quantities of gold were also detected, which is present in many of this artist's works to embellish some details of the representations. Also this work reports the first application of the external proton microbeam set-up available at CTN/IST in Portugal for the characterization of oil paintings.

Main atmospheric heavy metal sources in Portugal by biomonitor analysis

NASA Astrophysics Data System (ADS)

Reis, M. A.; Alves, L. C.; Wolterbeek, H. Th.; Verburg, T.; Freitas, M. C.; Gouveia, A.

1996-04-01

During the months of July and August of 1993 a lichen collection campaign was held in Portugal where about 250 samples were collected and analysed by thick target PIXE and INAA. Results for 43 different elements were obtained and a data base was built and subjected to Monte Carlo aided target transform factor analysis (MCATTFA), method developed at IRI TU Delft. 10 × 10 km coast and 50 × 50 km far from coast sampling grids were used for collection, concentration data as well as factor patterns were extrapolated to the whole country making use of an extinction rule of 1/r 3. In this work we present the results that were obtained based on a reduced data set of 22 elements measured by TTPIXE. The results for INAA data subset and the total data set are presented elsewhere.

Design and characterization of a prototype enzyme microreactor: quantification of immobilized transketolase kinetics.

PubMed

Matosevic, S; Lye, G J; Baganz, F

2010-01-01

In this work, we describe the design of an immobilized enzyme microreactor (IEMR) for use in transketolase (TK) bioconversion process characterization. The prototype microreactor is based on a 200-microm ID fused silica capillary for quantitative kinetic analysis. The concept is based on the reversible immobilization of His(6)-tagged enzymes via Ni-NTA linkage to surface derivatized silica. For the initial microreactor design, the mode of operation is a stop-flow analysis which promotes higher degrees of conversion. Kinetics for the immobilized TK-catalysed synthesis of L-erythrulose from substrates glycolaldehyde (GA) and hydroxypyruvate (HPA) were evaluated based on a Michaelis-Menten model. Results show that the TK kinetic parameters in the IEMR (V(max(app)) = 0.1 +/- 0.02 mmol min(-1), K(m(app)) = 26 +/- 4 mM) are comparable with those measured in free solution. Furthermore, the k(cat) for the microreactor of 4.1 x 10(5) s(-1) was close to the value for the bioconversion in free solution. This is attributed to the controlled orientation and monolayer surface coverage of the His(6)-immobilized TK. Furthermore, we show quantitative elution of the immobilized TK and the regeneration and reuse of the derivatized capillary over five cycles. The ability to quantify kinetic parameters of engineered enzymes at this scale has benefits for the rapid and parallel evaluation of evolved enzyme libraries for synthetic biology applications and for the generation of kinetic models to aid bioconversion process design and bioreactor selection as a more efficient alternative to previously established microwell-based systems for TK bioprocess characterization.

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.

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.).

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

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.

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.

Estimation of the failure risk of a maxillary premolar with different crack depths with endodontic treatment by computer-aided design/computer-aided manufacturing ceramic restorations.

PubMed

Lin, Chun-Li; Chang, Yen-Hsiang; Hsieh, Shih-Kai; Chang, Wen-Jen

2013-03-01

This study evaluated the risk of failure for an endodontically treated premolar with different crack depths, which was shearing toward the pulp chamber and was restored by using 3 different computer-aided design/computer-aided manufacturing ceramic restoration configurations. Three 3-dimensional finite element models designed with computer-aided design/computer-aided manufacturing ceramic onlay, endocrown, and conventional crown restorations were constructed to perform simulations. The Weibull function was incorporated with finite element analysis to calculate the long-term failure probability relative to different load conditions. The results indicated that the stress values on the enamel, dentin, and luting cement for endocrown restorations exhibited the lowest values relative to the other 2 restoration methods. Weibull analysis revealed that the overall failure probabilities in a shallow cracked premolar were 27%, 2%, and 1% for the onlay, endocrown, and conventional crown restorations, respectively, in the normal occlusal condition. The corresponding values were 70%, 10%, and 2% for the depth cracked premolar. This numeric investigation suggests that the endocrown provides sufficient fracture resistance only in a shallow cracked premolar with endodontic treatment. The conventional crown treatment can immobilize the premolar for different cracked depths with lower failure risk. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

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

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.

Roman onyx glass: A study of production recipes and colorants, using PIXE spectrometry

NASA Astrophysics Data System (ADS)

Fleming, S. J.; Swann, C. P.

1994-03-01

The most attractive Roman glass produced during the latter half of the 1st century B.C. was mosaic ware — vessels and dishes molded from arrays of composite, multi-colored canes which create abstract floral and geometric designs. We have studied a range of such vessels, all of them colored amber and white in a way which was intended to imitate elite vessels that were carved from onyx stone. We have differentiated three ways in which onyx patterns were achieved in this glass. Taking advantage of the spatial resolution and detection sensitivity of PIXE spectrometry, we have studied the "recipes" for colorants used in these onyx patterns, thus raising the notion that each one may have been fashionable in just certain regions of the Roman World, and/or in vogue only during a certain time period.

Deep coverage of the beer proteome.

PubMed

Grochalová, Martina; Konečná, Hana; Stejskal, Karel; Potěšil, David; Fridrichová, Danuše; Srbová, Eva; Ornerová, Kateřina; Zdráhal, Zbyněk

2017-06-06

We adopted an approach based on peptide immobilized pH gradient-isoelectric focusing (IPG-IEF) separation, coupled with LC-MS/MS, in order to maximize coverage of the beer proteome. A lager beer brewed using traditional Czech technology was degassed, desalted and digested. Tryptic peptides were separated by isoelectric focusing on an immobilized pH gradient strip and, after separation, the gel strip was divided into seven equally sized parts. Peptides extracted from gel fractions were analyzed by LC-MS/MS. This approach resulted in a three-fold increase in the number of proteins identified (over 1700) when compared to analysis of unfractionated beer processed by a filter-aided sample preparation (FASP). Over 1900 protein groups (PGs) in total were identified by both approaches. The study significantly extends knowledge about the beer proteome and demonstrates its complexity. Detailed knowledge of the protein content, especially gluten proteins, will enhance the evaluation of potential health risks related to beer consumption (coeliac disease) and will contribute to improving beer quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Immobilization of LiCl-Li 2 O pyroprocessing salt wastes in chlorosodalite using glass-bonded hydrothermal and salt-occlusion methods

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

Riley, Brian J.; Peterson, Jacob A.; Kroll, Jared O.

In this study, salt occlusion and hydrothermal processes were used to make chlorosodalite through reaction with a high-LiCl salt simulating a waste stream following pyrochemical treatment of oxide-based used nuclear fuel. Some products were reacted with glass binders to increase chlorosodalite yield through alkali ion exchange and aide in densification. Hydrothermal processes included reaction of the salt simulant in an acid digestion vessel with either zeolite 4A or sodium aluminate and colloidal silica. Chlorosodalite yields in the crystalline products were nearly complete in the glass-bonded materials at values of 100 mass% for the salt-occlusion method, up to 99.0 mass% formore » the hydrothermal synthesis with zeolite 4A, and up to 96 mass% for the hydrothermal synthesis with sodium aluminate and colloidal silica. These results show promise for using chemically stable chlorosodalite to immobilize oxide reduction salt wastes.« less

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).

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.

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…

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.

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.

Biosensor studies of collagen and laminin binding with immobilized Escherichia coli O157:H7 and inhibition with naturally occurring food additives

NASA Astrophysics Data System (ADS)

Medina, Marjorie B.

1999-01-01

Escherichia coli O157:H7 outbreaks were mostly due to consumption of undercooked contaminated beef which resulted in severe illness and several fatalities. Recalls of contaminated meat are costly for the meat industry. Our research attempts to understand the mechanisms of bacterial adhesion on animal carcass in order to eliminate or reduce pathogens in foods. We have reported the interactions of immobilized E. coli O157:H7 cells with extracellular matrix (ECM) components using a surface plasmon resonance biosensor (BIAcore). These studies showed that immobilized bacterial cells allowed the study of real-time binding interactions of bacterial surface with the ECM compounds, collagen I, laminin and fibronectin. Collagen I and laminin bound to the E. coli sensor surface with dissociation and association rates ranging from 106 to 109. Binding of collagen I and laminin mixture resulted in synergistic binding signals. An inhibition model was derived using collagen-laminin as the ligand which binds with E. coli sensor. A select group of naturally occurring food additives was evaluated by determining their effectivity in inhibiting the collagen-laminin binding to the bacterial sensor. Bound collagen-laminin was detached from the E. coli sensor surface with the aid of an organic acid. The biosensor results were verified with cell aggregation assays which were observed with optical and electron microscopes. These biosensor studies provided understanding of bacterial adhesion to connective tissue macromolecules. It also provided a model system for the rapid assessment of potential inhibitors that can be used in carcass treatment to inhibit or reduce bacterial contamination.

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.

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.

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.

PixEye Virtual Reality Training has the Potential of Enhancing Proficiency of Laser Trabeculoplasty Performed by Medical Students: A Pilot Study.

PubMed

Alwadani, Fahad; Morsi, Mohammed Saad

2012-01-01

To compare the surgical proficiency of medical students who underwent traditional training or virtual reality training for argon laser trabeculoplasty with the PixEye simulator. The cohort comprised of 47 fifth year male medical students from the College of Medicine, King Faisal University, Saudi Arabia. The cohort was divided into two groups: students (n = 24), who received virtual reality training (VR Group) and students (n = 23), who underwent traditional training (Control Group). After training, the students performed the trabeculoplasty procedure. All trainings were included concurrent power point presentations describing the details of the procedure. Evaluation of surgical performance was based on the following variables: missing the exact location with the laser, overtreatment, undertreatment and inadvertent laser shots to iris and cornea. The target was missed by 8% of the VR Group compared to 55% in the Control Group. Overtreatment and undertreatment was observed in 7% of the VR Group compared to 46% of the Control Group. Inadvertent laser application to the cornea or iris was performed by 4.5% of the VR Group compared to 34% of the Control Group. Virtual reality training on PixEye simulator may enhance the proficiency of medical students and limit possible surgical errors during laser trabeculoplasty. The authors have no financial interest in the material mentioned in this study.

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

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.

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.

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.

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.

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).

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

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).

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.

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.

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.

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.

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.

Pre-Hispanic ceramics analyzed using PIXE and radiographic techniques

NASA Astrophysics Data System (ADS)

Lima, S. C.; Rizzutto, M. A.; Added, N.; Barbosa, M. D. L.; Trindade, G. F.; Fleming, M. I. D. A.

2011-12-01

Ceramics objects are the most common artifacts found during excavation of archaeological sites and often depicts cultural habits and manufacturing technologies of the culture. The determination of macroscopic and microscopic characteristics of the ceramic objects such as the ceramic porosity, addition of tempers in the clay, main chemical components and the trace elements present in the ceramic can reveal many aspects about the manufacturing processes used by the culture, its degree of development, the provenance of the raw materials and the exchange networks. Also the radiography can help to investigate the manufactured processes, the size of the tempers used and the conservation status of the artifacts. In this present work two non-destructive techniques, radiography and PIXE (Particle Induced X-ray Emission) were used to characterize one set of thirty-six pre-Hispanic ceramic pieces from the Chimu Culture conserved in the Museu de Arqueologia e Etnologia (MAE/USP). The PIXE analyses performed in the external beam setup at LAMFI (Laboratório de Análise de Materiais por Feixes Iônicos) allowed measure the principal chemical elements such as Al, Si, K, Ti, Fe and Ca, present in this group of pieces. X-ray imagings allowed identify the manufacture processes, the granularity of the tempers used, as well as the similarity and the differences between the pieces studied.

Penicillin binding protein 3 of Staphylococcus aureus NCTC 8325-4 binds and activates human plasminogen.

PubMed

Kylväjä, Riikka; Ojalehto, Tuomas; Kainulainen, Veera; Virkola, Ritva; Westerlund-Wikström, Benita

2016-08-04

Staphylococcus aureus is a versatile pathogen expressing a number of virulence-associated adhesive molecules. In a previous study, we generated in a secretion-competent Escherichia coli strain a library of random FLAG-tag positive (FTP) polypeptides of S. aureus. To identify adhesive proteins and gain additional knowledge on putative virulence factors of S. aureus, we here screened the FTP library against human serum proteins. Staphylococcus aureus NCTC 8325-4, origin of the FTP library, adhered to immobilized plasminogen in vitro. In an enzyme-linked immunoassay a C-terminal part of penicillin binding protein 3 (PBP3), included in the FTP library, bound to immobilized plasminogen. We expressed and purified full-length PBP3 and its C-terminal fragments as recombinant proteins. In a time-resolved fluorometry-based assay the PBP3 polypeptides bound to immobilized plasminogen. The polypeptides enhanced formation of plasmin from plasminogen as analyzed by cleavage of a chromogenic plasmin substrate. The present findings, although preliminary, demonstrate reliably that S. aureus NCTC 8325-4 adheres to immobilized plasminogen in vitro and that the adhesion may be mediated by a C-terminal fragment of the PBP3 protein. The full length PBP3 and the penicillin binding C-terminal domain of PBP3 expressed as recombinant proteins bound plasminogen and activated plasminogen to plasmin. These phenomena were inhibited by the lysine analogue ε-aminocaproic acid suggesting that the binding is mediated by lysine residues. A detailed molecular description of surface molecules enhancing the virulence of S. aureus will aid in understanding of its pathogenicity and help in design of antibacterial drugs in the future.

Application of PIXE to the study of Renaissance style enamelled gold jewelry

NASA Astrophysics Data System (ADS)

Weldon, M.; Carlson, J.; Reedy, S.; Swann, C. P.

1996-04-01

This study examines and compares three pieces of Renaissance style gold and enamelled jewelry owned by the Walters Art Gallery, Baltimore, MD, USA. These are a 16th century Hat Badge of Adam and Eve, a 19th century Fortitude Pendant and a Diana Pendant presumed to be of the 16th century (The Walters Art Gallery, Jewelry, Ancient to Modern (Viking, New York, 1979)), Ref. [1]. PIXE spectroscopy was applied to examine the elemental composition of the gold and of the enamels. Compositional differences, including the use of post-Renaissance colorants, were found between the enamels in separate regions of each of the three pieces. The modern colorant, chromium, was, in fact, found in all of the pieces and uranium was found in only the Diana Pendant. There are some differences in the gold purity of the three objects; there are significant differences in the solders used even within one object, the Fortitude Pendant.

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.

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 selective conversion of glutamic acid in amino acid mixtures using glutamate decarboxylase--a means of separating amino acids for synthesizing biobased chemicals.

PubMed

Teng, Yinglai; Scott, Elinor L; Sanders, Johan P M

2014-01-01

Amino acids (AAs) derived from hydrolysis of protein rest streams are interesting feedstocks for the chemical industry due to their functionality. However, separation of AAs is required before they can be used for further applications. Electrodialysis may be applied to separate AAs, but its efficiency is limited when separating AAs with similar isoelectric points. To aid the separation, specific conversion of an AA to a useful product with different charge behavior to the remaining compounds is desired. Here the separation of L-aspartic acid (Asp) and L-glutamic acid (Glu) was studied. L-Glutamate α-decarboxylase (GAD, Type I, EC 4.1.1.15) was applied to specifically convert Glu into γ-aminobutyric acid (GABA). GABA has a different charge behavior from Asp therefore allowing a potential separation by electrodialysis. Competitive inhibition and reduced operational stability caused by Asp could be eliminated by maintaining a sufficiently high concentration of Glu. Immobilization of GAD does not reduce the enzyme's initial activity. However, the operational stability was slightly reduced. An initial study on the reaction operating in a continuous mode was performed using a column reactor packed with immobilized GAD. As the reaction mixture was only passed once through the reactor, the conversion of Glu was lower than expected. To complete the conversion of Glu, the stream containing Asp and unreacted Glu might be recirculated back to the reactor after GABA has been removed. Overall, the reaction by GAD is specific to Glu and can be applied to aid the electrodialysis separation of Asp and Glu. © 2014 American Institute of Chemical Engineers.

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.

8-Prenylnaringenin promotes recovery from immobilization-induced disuse muscle atrophy through activation of the Akt phosphorylation pathway in mice.

PubMed

Mukai, Rie; Horikawa, Hitomi; Lin, Pei-Yi; Tsukumo, Nao; Nikawa, Takeshi; Kawamura, Tomoyuki; Nemoto, Hisao; Terao, Junji

2016-12-01

8-Prenylnaringenin (8-PN) is a prenylflavonoid that originates from hop extracts and is thought to help prevent disuse muscle atrophy. We hypothesized that 8-PN affects muscle plasticity by promoting muscle recovery under disuse muscle atrophy. To test the promoting effect of 8-PN on muscle recovery, we administered an 8-PN mixed diet to mice that had been immobilized with a cast to one leg for 14 days. Intake of the 8-PN mixed diet accelerated recovery from muscle atrophy, and prevented reductions in Akt phosphorylation. Studies on cell cultures of mouse myotubes in vitro demonstrated that 8-PN activated the PI3K/Akt/P70S6K1 pathway at physiological concentrations. A cell-culture study using an inhibitor of estrogen receptors and an in vivo experiment with ovariectomized mice suggested that the estrogenic activity of 8-PN contributed to recovery from disuse muscle atrophy through activation of an Akt phosphorylation pathway. These data strongly suggest that 8-PN is a naturally occurring compound that could be used as a nutritional supplement to aid recovery from disuse muscle atrophy. Copyright © 2016 the American Physiological Society.

Research on Remote Sensing recognition features of Yuan Yang Terraces in Yunnan Province (China)

NASA Astrophysics Data System (ADS)

Xiang, Jie; Chen, Jianping; Lai, ZiLi; Yang, Wei

2016-04-01

Yuan Yang terraces is one of the most famous terraces in China, and it was successfully listed in the world heritage list at the 37th world heritage convention. On the one hand, Yuan Yang terraces retain more soil and water, to reduce both hydrological connectivity and erosion, and to support irrigation. On the other hand, It has the important tourism value, bring the huge revenue to local residents. In order to protect and make use of Yuan Yang terraces better, This study analyzed the spatial distribution and spectral characteristics of terraces:(1) Through visual interpretation, the study recognized the terraces based on the spatial adjusted remote sensing image (2010 Geoeye-1 with resolution of 1m/pix), and extracted topographic feature (elevation, slope, aspect, etc.) based on the digital elevation model with resolution of 20m/pix. The terraces cover a total area of about 11.58Km2, accounted for 24.4% of the whole study area. The terraces appear at range from 1400m to 1800m in elevation, 10°to 20°in slope, northwest to northeast in aspect; (2) Using the method of weight of evidence, this study assessed the importance of different topographic feature. The results show that the sort of importance: elevation>slope>aspect; (3) The study counted the Normalized Difference Vegetation Index (NDVI) changes of terraces throughout the year, based on the landsat-5 image with resolution of 30m/pix. The results show that the changes of terraces' NDVI are bigger than other stuff (e.g. forest, road, house, etc.). Those work made a good preparations for establishing the dynamic remote sensing monitoring system of Yuan Yang terraces.

Stability studies of immobilized lipase on rice husk and eggshell membrane

NASA Astrophysics Data System (ADS)

Abdulla, R.; Sanny, S. A.; Derman, E.

2017-06-01

Lipase immobilization for biodiesel production is gaining importance day by day. In this study, lipase from Burkholderia cepacia was immobilized on activated support materials namely rice husk and egg shell membrane. Both rice husk and eggshell membrane are natural wastes that holds a lot of potential as immobilization matrix. Rice husk and eggshell membrane were activated with glutaraldehyde. Lipase was immobilized on the glutaraldehyde-activated support material through adsorption. Immobilization efficiency together with enzyme activity was observed to choose the highest enzyme loading for further stability studies. Immobilization efficiency of lipase on rice husk was 81 as compared to an immobilization efficiency of 87 on eggshell membrane. Immobilized lipase on eggshell membrane exhibited higher enzyme activity as compared to immobilized lipase on rice husk. Eggshell membrane also reported higher stability than rice husk as immobilization matrix. Both types of immobilized lipase retatined its activity after ten cycles of reuse. In short, eggshell membrane showed to be a better immobilization platform for lipase as compared to rice husk. However, with further improvement in technique of immobilization, the stability of both types of immobilized lipase can be improved to a greater extent.

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.

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.

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.

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.

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.

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.

Biotechnology in Food Production and Processing

NASA Astrophysics Data System (ADS)

Knorr, Dietrich; Sinskey, Anthony J.

1985-09-01

The food processing industry is the oldest and largest industry using biotechnological processes. Further development of food products and processes based on biotechnology depends upon the improvement of existing processes, such as fermentation, immobilized biocatalyst technology, and production of additives and processing aids, as well as the development of new opportunities for food biotechnology. Improvements are needed in the characterization, safety, and quality control of food materials, in processing methods, in waste conversion and utilization processes, and in currently used food microorganism and tissue culture systems. Also needed are fundamental studies of the structure-function relationship of food materials and of the cell physiology and biochemistry of raw materials.

Trapping, Deformation, and Rotation of Giant Unilamellar Vesicles in Octode Dielectrophoretic Field Cages

PubMed Central

Korlach, J.; Reichle, C.; Müller, T.; Schnelle, T.; Webb, W. W.

2005-01-01

The behavior of freestanding lipid bilayer membranes under the influence of dielectric force potentials was studied by trapping, holding, and rotating individual giant unilamellar vesicles (GUVs) inside dielectrophoretic microfield cages. Using laser scanning confocal microscopy and three-dimensional image reconstructions of GUVs labeled with fluorescent membrane probes, field strength and frequency-dependent vesicle deformations were observed which are explained by calculations of the dielectric force potentials inside the cage. Dynamical membrane properties under the influence of the field cage were studied by fluorescence correlation spectroscopy, circumventing potential artifacts associated with measurements involving GUV immobilization on support surfaces. Lipid transport could be accelerated markedly by the applied fields, aided by hydrodynamic fluid streaming which was also studied by fluorescence correlation spectroscopy. PMID:15863477

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.

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.

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.

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.

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.

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.

Aroma Release in Wine Using Co-Immobilized Enzyme Aggregates.

PubMed

Ahumada, Katherine; Martínez-Gil, Ana; Moreno-Simunovic, Yerko; Illanes, Andrés; Wilson, Lorena

2016-11-08

Aroma is a remarkable factor of quality and consumer preference in wine, representing a distinctive feature of the product. Most aromatic compounds in varietals are in the form of glycosidic precursors, which are constituted by a volatile aglycone moiety linked to a glucose residue by an O -glycosidic bond; glucose is often linked to another sugar (arabinose, rhamnose or apiose). The use of soluble β-glycosidases for aroma liberation implies the addition of a precipitating agent to remove it from the product and precludes its reuse after one batch. An attractive option from a technological perspective that will aid in removing such constraints is the use of immobilized glycosidases. Immobilization by aggregation and crosslinking is a simple strategy producing enzyme catalysts of very high specific activity, being an attractive option to conventional immobilization to solid inert supports. The purpose of this work was the evaluation of co-immobilized β-glycosidases crosslinked aggregates produced from the commercial preparation AR2000, which contains the enzymes involved in the release of aromatic terpenes in Muscat wine (α-l-arabinofuranosidase and β-d-glucopyranosidase). To do so, experiments were conducted with co-immobilized crosslinked enzyme aggregates (combi-CLEAs), and with the soluble enzymes, using an experiment without enzyme addition as control. Stability of the enzymes at the conditions of winemaking was assessed and the volatiles composition of wine was determined by SPE-GC-MS. Stability of enzymes in combi-CLEAs was much higher than in soluble form, 80% of the initial activity remaining after 60 days in contact with the wine; at the same conditions, the soluble enzymes had lost 80% of their initial activities after 20 days. Such higher stabilities will allow prolonged use of the enzyme catalyst reducing its impact in the cost of winemaking. Wine treated with combi-CLEAs was the one exhibiting the highest concentration of total terpenes (18% higher than the control) and the highest concentrations of linalool (20% higher), nerol (20% higher) and geraniol (100% higher), which are the most important terpenes in determining Muscat typicity. Co-immobilized enzymes were highly stable at winemaking conditions, so their reutilization is possible and technologically attractive by reducing the impact of enzyme cost on winemaking cost.

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.

Quantitative mapping of intracellular cations in the human amniotic membrane

NASA Astrophysics Data System (ADS)

Moretto, Ph.; Llabador, Y.; Simonoff, M.; Razafindrabe, L.; Bara, M.; Guiet-Bara, A.

1993-05-01

The effect of magnesium and taurine on the permeability of cell membranes to monovalent cations has been investigated using the Bordeaux nuclear microprobe. PIXE and RBS techniques have been used to provide quantitative measurements and ion distributions in the isolated amniotic membrane. This physiological model for cellular exchanges allowed us to reveal the distribution of most elements involved in cellular pathways and the modifications under different experimental conditions of incubation in physiological fluids. The PIXE microanalysis provided an original viewpoint on these mechanisms. Following this first study, the amnion compact lamina was found to play a role which was not, up to now, taken into account in the interpretation of electrophysiological experimentations. The release of some ionic species, such as K +, from the epithelial cells, during immersion in isotonic fluids, could have been hitherto underestimated.

Tang dynasty (618-907) bowl measured with PIXE

NASA Astrophysics Data System (ADS)

Laitinen, M.; Käyhkö, M.; Hahn, G.; von Uexküll-Güldenband, N.; Sajavaara, T.

2017-09-01

Brownish bowl originating from an underwater shipwreck located near Belitung island in the Java Sea, some 600 km south-east from Singapore, has been measured with particle induced X-ray emission. This study was a pilot project for the - now a spin-off company - Recenart research team where one target was to evaluate the authenticity of the different type of art objects. PIXE measurements were done from three different material positions from a single bowl received from a customer. These locations were categorized as a bluish/greenish pigment (under glaze), thick glaze and the body clay. When the obtained data was compared to the other references from different dynasties and kiln sites, the closest match was indeed the Tang dynasty, Tongguan/Ghangsha kiln-site potsherds - from where the bowl in question was also suspected to originate.

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.

Immobilization of BSA, enzymes and cells of Bacillus stearothermophilus onto cellulose polygalacturonic acid and starch based graft copolymers containing maleic arhydride

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

Beddows, C.G.; Gil, M.H.; Guthrie, J.T.

1986-01-01

Poly(maleic anhydride styrene) graft copolymers of cellulose, pectin polygalacturonic acid salt, calcium polygalacturonate, and starch were prepared and used to immobilize proteins. The cellulose grafts coupled quite appreciable quantities of acid phosphatase, glucose oxidase, and trypsin. However, the general retention of activity was somewhat disappointing. Further investigation with acid phosphatase showed that the amount of enzyme immobilized increased as the amount of anhydride in the graft copolymer increased but no such relationship existed for the enzymic activity. The cellulose graft copolymers were hydrolyzed and it appeared that the carboxyl group aided adsorption of the enzyme. Attempts to couple acid phosphatasemore » using CMC through the free carboxyl groups, created by hydrolysis, gave only a small increase in the extent of protein coupling. However, the unhydrolyzed system gave a useful degree of immobilization of cells of Bacillus stearothermophilus, as did a poly(maleic anhydride/styrene)-cocellulose system. Attempts to improve the activity by using grafts based on other polysaccharide supports met with mixed success. Pectin products were soluble. Polygalacturonic acid products were partially soluble and extremely high levels of enzymic activity were obtained. This was probably due in part to the hydrophilic nature of the system, which also encouraged absorption of the enzyme. Attempts were made to reduce the solubility by using the calcium pectinate salt. Immobilization of acid phosphatase and trypsin resulted in increased protein coupling but relatively poor activities were attained. Calcium polygalacturonate was used to prepare an insoluble graft copolymeric system containing acrylonitrile-comaleic anhydride. The resulting gels gave excellent coupling with acid phosphatase which had a very good retention of activity.« less

Nickel toxicity in the hepatopancreas of an isopod Porcellio scaber ( Oniscidea)

NASA Astrophysics Data System (ADS)

Tarnawska, M.; Migula, P.; Przybyłowicz, W.; Mesjasz-Przybyłowicz, J.; Augustyniak, M.

2007-07-01

This study is focused on recognizing how the functional role of hepatopancreas, the main metal storage organ in woodlice, is affected by the excess of nickel, a toxic element to soil invertebrates. Chronic Ni toxicity (24 weeks) was studied on four groups of woodlice kept on dry shredded maple leaves contaminated with Ni at average concentrations of 0.1 μg g -1 (control), 8.0 μg g -1 (Ni1), 75 μg g -1 (Ni2) and 270 μg g -1(Ni3) dry weight. Micro-PIXE mapping of elemental distribution in the hepatopancreas of the Porcellio scaber woodlice was used to study relations between nickel and other elements in individuals exposed to different metal concentrations in the diet. Data were processed using GeoPIXE II software. Transmission electron microscopy (TEM) was used to check the relations between ultrastructural changes in hepatopancreatic cells and nickel tissue burden. Elemental mapping showed a dose-related nickel bioaccumulation in the hepatopancreas at concentrations from 3 μg g -1 (uncontaminated control animals) to nearly 840 μg g -1 (Ni3). Generally, nickel was distributed uniformly in small aggregations. A combined evaluation of elemental maps and electronograms showed that aggregations of nickel in arbitrarily selected micro-areas in PIXE maps could be the granular structures observed in TEM electronograms. The mechanism of Ni sequestration in the hepatopancreas could be similar to this used for cadmium or lead. The sequences of ultrastructural changes, which follow the increased burdens of Ni in the hepatopancreatic cells, were: the increase of intracellular electron-dense granules, increase in the number of myelin-like structures, intensified mitochondrial swelling and appearance of concentrically arranged, rough endoplasmic reticulum.

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 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.

Modeling the effectiveness of U(VI) biomineralization in dual-porosity porous media

NASA Astrophysics Data System (ADS)

Rotter, B. E.; Barry, D. A.; Gerhard, J. I.; Small, J. S.

2011-05-01

SummaryUranium contamination is a serious environmental concern worldwide. Recent attention has focused on the in situ immobilization of uranium by stimulation of dissimilatory metal-reducing bacteria (DMRB). The objective of this work was to investigate the effectiveness of this approach in heterogeneous and structured porous media, since such media may significantly affect the geochemical and microbial processes taking place in contaminated sites, impacting remediation efficiency during biostimulation. A biogeochemical reactive transport model was developed for uranium remediation by immobile-region-resident DMRB in two-region porous media. Simulations were used to investigate the parameter sensitivities of the system over wide-ranging geochemical, microbial and groundwater transport conditions. The results suggest that optimal biomineralization is generally likely to occur when the regional mass transfer timescale is less than one-thirtieth the value of the volumetric flux timescale, and/or the organic carbon fermentation timescale is less than one-thirtieth the value of the advective timescale, and/or the mobile region porosity ranges between equal to and four times the immobile region porosity. Simulations including U(VI) surface complexation to Fe oxides additionally suggest that, while systems exhibiting U(VI) surface complexation may be successfully remediated, they are likely to display different degrees of remediation efficiency over varying microbial efficiency, mobile-immobile mass transfer, and porosity ratios. Such information may aid experimental and field designs, allowing for optimized remediation in dual-porosity (two-region) biostimulated DMRB U(VI) remediation schemes.

Solution-derived sodalite made with Si- and Ge-ethoxide precursors for immobilizing electrorefiner salt

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

Riley, Brian J.; Lepry, William C.; Crum, Jarrod V.

Chlorosodalite has the general form of Na8(AlSiO4)6Cl2 and this paper describes experiments conducted to synthesize sodalite to immobilize a mixed chloride salt using solution-based techniques. Sodalites were made using different Group IV contributions from either Si(OC2H5)4 or Ge(OC2H5)4, NaAlO2, and a simulated spent electrorefiner salt solution containing a mixture of alkali, alkaline earth, and lanthanide chlorides. Additionally, 6 glass binders at low loadings of 5 mass% were evaluated as sintering aids for the consolidation process. The approach of using the organic Group IV additives can be used to produce large quantities of sodalite at room temperature and shows promise overmore » a method where colloidal silica is used as the silica source. However, the small particle sizes inhibited densification during pressure-less sintering.« less

Comperative study of catalase immobilization on chitosan, magnetic chitosan and chitosan-clay composite beads.

PubMed

Başak, Esra; Aydemir, Tülin; Dinçer, Ayşe; Becerik, Seda Çınar

2013-12-01

Catalase was immobilized on chitosan and modified chitosan. Studies were carried out on free-immobilized catalase concerning the determination of optimum temperature, pH, thermal, storage stability, reusability, and kinetic parameters. Optimum temperature and pH for free catalase and catalase immobilized were found as 35°C and 7.0, respectively. After 100 times of repeated tests, the immobilized catalases on chitosan-clay and magnetic chitosan maintain over 50% and 60% of the original activity, respectively. The ease of catalase immobilization on low-cost matrices and good stability upon immobilization in the present study make it a suitable product for further use in the food industry.

Study of the atmospheric aerosol composition in equatorial Africa using PIXE as analytical technique

NASA Astrophysics Data System (ADS)

Maenhaut, W.; Akilimali, K.

1987-03-01

Small Nuclepore total filter holders and a single orifice 8-stage cascade impactor were used to collect atmospheric aerosol samples in Kinshasa, Zaire, and Butare, Rwanda. The samples were analyzed for about 20 elements by means of the PIXE technique. The results obtained for parallel samples, taken with two total filter holders and one cascade impactor, were generally in excellent agreement, suggesting that the different samplers collected very similar aerosol particle populations. Most elements were associated with a crustal dust dispersion source, which may include road dust dispersal. The Butare samples, particularly those collected during the night, were significantly influenced by biomass burning, as was deduced from enhanced filter blackness and noncrustal K levels. The pyrogenic component also contained P, S, Mn and Rb. Br and Pb were highly enriched at both locations, indicating that automotive sources had a strong influence on the aerosol composition.

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.

Studies on bronze pre-monetary signs found in Dobroudja using XRF and micro-PIXE

NASA Astrophysics Data System (ADS)

Constantinescu, B.; Cristea-Stan, D.; Talmatchi, G.; Ceccato, D.

2016-03-01

We performed compositional analyses on 180 Scythian-type arrowheads and pre-monetary signs using XRF method and on 60 small fragments of such items (approx. 100 microns diameter), sampling being performed on previously corrosion-cleaned areas on their surface, using micro-PIXE. The items are found in Dobroudja, Istros-Histria region. The most relevant for numismatists result is that for each finding place the same type of alloy was used both for fighting arrowheads and for pre-monetary signs. Our analyses revealed three types of alloys: Cu-Sn-Pb ("normal" bronze), Cu-Sn-Mn-Pb and Cu-Sn-Sb-Pb. The presence of antimony suggests the use of fahlore-type poly-metals deposits, most probably from Caucasus Mountains. The problem of ancient bronze containing manganese is more complicated; an explanation could be the use of manganese oxides as flux necessary to smelt oxidized ores.

An ion accelerator for undergraduate research and teaching

NASA Astrophysics Data System (ADS)

Monce, Michael

1997-04-01

We have recently upgraded our 400kV, single beam line ion accelerator to a 1MV, multiple beam line machine. This upgrade has greatly expanded the opportunities for student involvement in the laboratory. We will describe four areas of work in which students now participate. The first is the continuing research being conducted in excitations produced in ion-molecule collisions, which recently involved the use of digital imaging. The second area of research now opened up by the new accelerator involves PIXE. We are currently beginning a cross disciplinary study of archaeological specimens using PIXE and involving students from both anthropology and physics. Finally, two beam lines from the accelerator will be used for basic work in nuclear physics: Rutherford scattering and nuclear resonances. These two nuclear physics experiments will be integrated into our sophomore-junior level, year-long course in experimental physics.

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.

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).

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.

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.

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.

Immobilization of Energetics on Live Fire Ranges (CU-1229). Revision 1.0

DTIC Science & Technology

2004-07-31

Its cost ultimately may be prohibitive for large scale application in some areas, but its humic composition should aid adsorption of energetics and/or...acetonitrile) to sterile glass bottles, evaporating the solvent under a stream of nitrogen, adding a known volume of CaCl2, and sonicating/mixing until all...filtration)- Same as (a) above, except that the cleared supernatant was passed through a 0.45 µm glass fiber syringe filter prior to scintillation counting

Thrombin immobilization to methacrylic acid grafted poly(3-hydroxybutyrate) and its in vitro application.

PubMed

Akkaya, Alper; Pazarlioglu, Nurdan

2013-01-01

Poly(3-hydroxybutyrate) is nontoxic and biodegradable, with good biocompatibility and potential support for long-term implants. For this reason, it is a good support for enzyme immobilization. Enzyme immobilization could not be done directly because poly(3-hydroxybutyrate) has no functional groups. Therefore, modification should be done for enzyme immobilization. In this study, methacrylic acid was graft polymerized to poly(3-hydroxybutyrate) and thrombin was immobilized to polymethacrylic acid grafted poly(3-hydroxybutyrate). In fact, graft polymerization of methacrylic acid to poly(3-hydroxybutyrate) and thrombin immobilization was a model study. Biomolecule immobilized poly(3-hydroxybutyrate) could be used as an implant. Thrombin was selected as a biomolecule for this model study and it was immobilized to methacrylic acid grafted poly(3-hydroxybutyrate). Then the developed product was used to stop bleeding.

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 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

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.

Retargeting of adenovirus vectors through genetic fusion of a single-chain or single-domain antibody to capsid protein IX.

PubMed

Poulin, Kathy L; Lanthier, Robert M; Smith, Adam C; Christou, Carin; Risco Quiroz, Milagros; Powell, Karen L; O'Meara, Ryan W; Kothary, Rashmi; Lorimer, Ian A; Parks, Robin J

2010-10-01

Adenovirus (Ad) vectors are the most commonly used system for gene therapy applications, due in part to their ability to infect a wide array of cell types and tissues. However, many therapies would benefit from the ability to target the Ad vector only to specific cells, such as tumor cells for cancer gene therapy. In this study, we investigated the utility of capsid protein IX (pIX) as a platform for the presentation of single-chain variable-fragment antibodies (scFv) and single-domain antibodies (sdAb) for virus retargeting. We show that scFv can be displayed on the capsid through genetic fusion to native pIX but that these molecules fail to retarget the virus, due to improper folding of the scFv. Redirecting expression of the fusion protein to the endoplasmic reticulum (ER) results in correct folding of the scFv and allows it to recognize its epitope; however, ER-targeted pIX-scFv was incorporated into the Ad capsid at a very low level which was not sufficient to retarget virus infection. In contrast, a pIX-sdAb construct was efficiently incorporated into the Ad capsid and enhanced virus infection of cells expressing the targeted receptor. Taken together, our data indicate that pIX is an effective platform for presentation of large targeting polypeptides on the surface of the virus capsid, but the nature of the ligand can significantly affect its association with virions.

Paralytic activity of lysophosphatidylcholine from saliva of the waterbug Belostoma anurum.

PubMed

Silva-Cardoso, Lívia; Caccin, Paola; Magnabosco, Anna; Patrón, Maria; Targino, Mariane; Fuly, André; Oliveira, Giselle A; Pereira, Marcos H; do Carmo, Maria das Graças T; Souza, Amanda S; Silva-Neto, Mário A C; Montecucco, Cesare; Atella, Georgia C

2010-10-01

Lysophosphatidylcholine (LPC) is a major bioactive lipid that is enzymatically generated by phospholipase A(2) (PLA(2)). Previously, we showed that LPC is present in the saliva of the blood-sucking hemipteran Rhodnius prolixus and modulates cell-signaling pathways involved in vascular biology, which aids blood feeding. Here, we show that the saliva of the predator insect Belostoma anurum contains a large number of lipids with LPC accounting for 25% of the total phospholipids. A PLA(2) enzyme likely to be involved in LPC generation was characterized. The activity of this enzyme is 5-fold higher in Belostoma saliva than in other studied hemipterans, suggesting a close association with the predator feeding habits of this insect. Belostoma employs extra-oral digestion, which allows for ingestion of larger prey than itself, including small vertebrates such as amphibians and fish. Therefore, prey immobilization during digestion is essential, and we show here that Belostoma saliva and B. anurum saliva purified LPC have paralytic activity in zebrafish. This is the first evidence that lysophospholipids might play an important role in prey immobilization, in addition to contributing to blood feeding, and might have been an evolutionary acquisition that occurred long before the appearance of hematophagy in this animal group.

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.

Beyond Iron: Iridium-Containing P450 Enzymes for Selective Cyclopropanations of Structurally Diverse Alkenes

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

Key, Hanna M.; Dydio, Paweł; Liu, Zhennan

Enzymes catalyze organic transformations with exquisite levels of selectivity, including chemoselectivity, stereoselectivity, and substrate selectivity, but the types of reactions catalyzed by enzymes are more limited than those of chemical catalysts. Thus, the convergence of chemical catalysis and biocatalysis can enable enzymatic systems to catalyze abiological reactions with high selectivity. Recently, we disclosed artificial enzymes constructed from the apo form of heme proteins and iridium porphyrins that catalyze the insertion of carbenes into a C-H bond. Here, we postulated that the same type of Ir(Me)-PIX enzymes could catalyze the cyclopropanation of a broad range of alkenes with control of multiplemore » modes of selectivity. Here, we report the evolution of artificial enzymes that are highly active and highly stereoselective for the addition of carbenes to a wide range of alkenes. These enzymes catalyze the cyclopropanation of terminal and internal, activated and unactivated, electron-rich and electron-deficient, conjugated and nonconjugated alkenes. In particular, Ir(Me)-PIX enzymes derived from CYP119 catalyze highly enantio- and diastereoselective cyclopropanations of styrene with ±98% ee, > 70:1 dr, > 75% yield, and ~10,000 turnovers (TON), as well as 1,2-disubstituted styrenes with up to 99% ee, 35:1 dr, and 54% yield. Moreover, Ir(Me)-PIX enzymes catalyze cyclopropanation of internal, unactivated alkenes with up to 99% stereoselectivity, 76% yield, and 1300 TON. They also catalyze cyclopropanation of natural products with diastereoselectivities that are complementary to those attained with standard transition metal catalysts. Finally, Ir(Me)-PIX P450 variants react with substrate selectivity that is reminiscent of natural enzymes; they react preferentially with less reactive internal alkenes in the presence of more reactive terminal alkenes. Altogether, the studies reveal the suitability of Ir-containing P450s to combine the broad reactivity and substrate scope of transition metal catalysts with the exquisite selectivity of enzymes, generating catalysts that enable reactions to occur with levels and modes of activity and selectivity previously unattainable with natural enzymes or transition metal complexes alone.« less

Beyond Iron: Iridium-Containing P450 Enzymes for Selective Cyclopropanations of Structurally Diverse Alkenes

DOE PAGES

Key, Hanna M.; Dydio, Paweł; Liu, Zhennan; ...

2017-04-01

Enzymes catalyze organic transformations with exquisite levels of selectivity, including chemoselectivity, stereoselectivity, and substrate selectivity, but the types of reactions catalyzed by enzymes are more limited than those of chemical catalysts. Thus, the convergence of chemical catalysis and biocatalysis can enable enzymatic systems to catalyze abiological reactions with high selectivity. Recently, we disclosed artificial enzymes constructed from the apo form of heme proteins and iridium porphyrins that catalyze the insertion of carbenes into a C-H bond. Here, we postulated that the same type of Ir(Me)-PIX enzymes could catalyze the cyclopropanation of a broad range of alkenes with control of multiplemore » modes of selectivity. Here, we report the evolution of artificial enzymes that are highly active and highly stereoselective for the addition of carbenes to a wide range of alkenes. These enzymes catalyze the cyclopropanation of terminal and internal, activated and unactivated, electron-rich and electron-deficient, conjugated and nonconjugated alkenes. In particular, Ir(Me)-PIX enzymes derived from CYP119 catalyze highly enantio- and diastereoselective cyclopropanations of styrene with ±98% ee, > 70:1 dr, > 75% yield, and ~10,000 turnovers (TON), as well as 1,2-disubstituted styrenes with up to 99% ee, 35:1 dr, and 54% yield. Moreover, Ir(Me)-PIX enzymes catalyze cyclopropanation of internal, unactivated alkenes with up to 99% stereoselectivity, 76% yield, and 1300 TON. They also catalyze cyclopropanation of natural products with diastereoselectivities that are complementary to those attained with standard transition metal catalysts. Finally, Ir(Me)-PIX P450 variants react with substrate selectivity that is reminiscent of natural enzymes; they react preferentially with less reactive internal alkenes in the presence of more reactive terminal alkenes. Altogether, the studies reveal the suitability of Ir-containing P450s to combine the broad reactivity and substrate scope of transition metal catalysts with the exquisite selectivity of enzymes, generating catalysts that enable reactions to occur with levels and modes of activity and selectivity previously unattainable with natural enzymes or transition metal complexes alone.« less

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.

Assessing the accuracy and repeatability of automated photogrammetrically generated digital surface models from unmanned aerial system imagery

NASA Astrophysics Data System (ADS)

Chavis, Christopher

Using commercial digital cameras in conjunction with Unmanned Aerial Systems (UAS) to generate 3-D Digital Surface Models (DSMs) and orthomosaics is emerging as a cost-effective alternative to Light Detection and Ranging (LiDAR). Powerful software applications such as Pix4D and APS can automate the generation of DSM and orthomosaic products from a handful of inputs. However, the accuracy of these models is relatively untested. The objectives of this study were to generate multiple DSM and orthomosaic pairs of the same area using Pix4D and APS from flights of imagery collected with a lightweight UAS. The accuracy of each individual DSM was assessed in addition to the consistency of the method to model one location over a period of time. Finally, this study determined if the DSMs automatically generated using lightweight UAS and commercial digital cameras could be used for detecting changes in elevation and at what scale. Accuracy was determined by comparing DSMs to a series of reference points collected with survey grade GPS. Other GPS points were also used as control points to georeference the products within Pix4D and APS. The effectiveness of the products for change detection was assessed through image differencing and observance of artificially induced, known elevation changes. The vertical accuracy with the optimal data and model is ≈ 25 cm and the highest consistency over repeat flights is a standard deviation of ≈ 5 cm. Elevation change detection based on such UAS imagery and DSM models should be viable for detecting infrastructure change in urban or suburban environments with little dense canopy vegetation.

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.

Anti-fouling properties of Fab' fragments immobilized on silane-based adlayers

NASA Astrophysics Data System (ADS)

Crivianu-Gaita, Victor; Romaschin, Alexander; Thompson, Michael

2015-12-01

Biosensors require surfaces that are highly specific towards the target analyte and that are minimally fouling. However, surface tuning to minimize fouling is a difficult task. The last decade has seen an increase in the use of immobilized antigen-binding antibody fragments (Fab') in biosensors. One Fab' linker compound S-(11-trichlorosilyl-undecanyl)-benzothiosulfonate (TUBTS) and three spacers were used to create the silane-based adlayers. The ultra-high frequency electromagnetic piezoelectric acoustic sensor (EMPAS) was used to gauge the fouling properties of the various surfaces using bovine serum albumin (BSA), goat IgG, and mouse serum. X-ray photoelectron spectroscopy (XPS), contact angle, and atomic force microscopy (AFM) were employed to characterize the surfaces. It was discovered that immobilized oriented Fab' fragments reduced the fouling levels of surfaces up to 80% compared to the surfaces without fragments. An explanation for this phenomenon is that the antibody fragments increase the hydration of the surfaces and aid in the formation of an anti-fouling water barrier. The anti-fouling effect of the Fab' fragments is at its maximum when there is an even distribution of fragments across the surfaces. Finally, using Fab'-covered surfaces, a cancer biomarker was detected from serum, showing the applicability of this work to the field of biodetection.

Modeling and simulation of tumor-influenced high resolution real-time physics-based breast models for model-guided robotic interventions

NASA Astrophysics Data System (ADS)

Neylon, John; Hasse, Katelyn; Sheng, Ke; Santhanam, Anand P.

2016-03-01

Breast radiation therapy is typically delivered to the patient in either supine or prone position. Each of these positioning systems has its limitations in terms of tumor localization, dose to the surrounding normal structures, and patient comfort. We envision developing a pneumatically controlled breast immobilization device that will enable the benefits of both supine and prone positioning. In this paper, we present a physics-based breast deformable model that aids in both the design of the breast immobilization device as well as a control module for the device during every day positioning. The model geometry is generated from a subject's CT scan acquired during the treatment planning stage. A GPU based deformable model is then generated for the breast. A mass-spring-damper approach is then employed for the deformable model, with the spring modeled to represent a hyperelastic tissue behavior. Each voxel of the CT scan is then associated with a mass element, which gives the model its high resolution nature. The subject specific elasticity is then estimated from a CT scan in prone position. Our results show that the model can deform at >60 deformations per second, which satisfies the real-time requirement for robotic positioning. The model interacts with a computer designed immobilization device to position the breast and tumor anatomy in a reproducible location. The design of the immobilization device was also systematically varied based on the breast geometry, tumor location, elasticity distribution and the reproducibility of the desired tumor location.

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.

A new model of skeletal muscle atrophy induced by immobilization using a hook-and-loop fastener in mice

PubMed Central

Aihara, Masahiro; Hirose, Noboru; Katsuta, Wakana; Saito, Fumiaki; Maruyama, Hitoshi; Hagiwara, Hiroki

2017-01-01

[Purpose] To study muscle atrophy, the muscle atrophy model mice have been used frequently. In particular, cast immobilization is the most common method to induce muscle atrophy. However, it is time consuming and often causes adverse events including skin injury, edema, and necrosis. The present study, we developed a hook-and-loop fastener (Velcro) immobilization method as a new, simple, and less invasive approach to induce muscle atrophy. [Subjects and Methods] Mice were bandaged in the knee joint extension and ankle plantar extension position. Muscle atrophy was induced by either winding a cast or Velcro around the limb. [Results] According to weight and fiber size, Velcro immobilization induced equivalent muscle atrophy to cast immobilization. Velcro immobilization reduced significantly the time for the procedure and the frequency of adverse events. [Conclusion] Velcro immobilization can induce muscle atrophy comparable to cast immobilization, but in a shorter time and with less complications. Velcro immobilization may contribute to the study of disuse muscle atrophy in clinical practice of physical therapy using a mouse model. PMID:29184288

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.

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.

[First aid for multiple trauma patients: investigative survey in the Firenze-Bologna area].

PubMed

Crescioli, G L; Donati, D; Federici, A; Rasero, L

1999-01-01

Overall mortality ascribable to multiple traumas, that in Italy is responsible for about 8,000 death/year, is strictly dependent on the function of the so called Trauma Care System. This study reports on an epidemiological survey conducted in the urban area of Florence along a 23-month period (from Jan 97 to Nov 99), with the aim to identify the typology of traumas and the first aid care delivered to the person until hospital admission. These data were compared to those collected in the urban area of Bologna because the composition of the first-aid team is different, being nurses, in Bologna, an integral component of the first aid system. On a total of 118 multiple traumas, 17% was represented by isolated head trauma, while in 72% involvement of other organs was present in addition to the head; 11% of cases were abdominal or thoracic traumas, 1% of lower extremities. In 46% the cause of trauma was a car accident. The complexity of care delivered to the person with trauma was less in the Florence survey, as indicated by the immobilization of patients, performed in only 11% of cases as compared to 47% in Bologna, by the application of the cervical collar, applied in 12% versus 62% of traumas. Although the two samples are not strictly comparable, these data suggest that the presence of nurses in the Trauma Care System can be one of the elements of improvement of the quality of delivered care.

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.

Stability improvement of immobilized lactoperoxidase using polyaniline polymer.

PubMed

Jafary, Fariba; Kashanian, Soheila; Sharieat, Ziadin Samsam; Jafary, Farzaneh; Omidfar, Kobra; Paknejad, Maliheh

2012-12-01

Enzyme engineering via immobilization techniques is perfectly compatible against the other chemical or biological approximate to improve enzyme functions and stability. In this study lactoperoxidase was immobilized onto polyaniline polymer activated with glutaraldehyde as a bifunctional agent, to improve enzyme properties. Polyaniline polymer was used due its unique physical and chemical properties to immobilize lactoperoxidase (LPO). The optimum activity of immobilized LPO was observed at pH 6 and 55 °C, which has been increased about 10 °C for the immobilized enzyme. The immobilized enzyme maintained absolutely active for 60 days whereas the native enzyme lost 80 % of its initial activity within this period of time. Moreover, the immobilized enzyme can be reused for several times without loss of activity. The kinetic parameter studies showed slight differences between free and immobilized enzymes. The K(m) and K(m.app) were calculated to be 0.6 and 0.4; also V(max) and V(max.app) were 1.3 and 0.9 respectively.

Characteristics of pectinase treated with ultrasound both during and after the immobilization process.

PubMed

Ma, Xiaobin; Wang, Danli; Yin, Michelle; Lucente, Juliet; Wang, Wenjun; Ding, Tian; Ye, Xingqian; Liu, Donghong

2017-05-01

In this study, ultrasound was applied both during and after the immobilization process and characteristics of different immobilized pectinase samples were studied. When introduced during the immobilization process, ultrasound at an intensity of 9WmL -1 for 20min increased the immobilization yield 92.28% more than the control. When introduced to the already immobilized pectinase, ultrasound at an intensity of 4.5WmL -1 for 10min increased the pectinase activity by 30.05%. Results of scanning electron microscope demonstrated that ultrasound increased surface area and loosened structures of immobilized enzymes. Higher V max and lower K m were obtained after ultrasound treatment, indicating the increased catalytic efficiency and enhanced affinity of immobilized pectinase. Furthermore, the optimum temperature and pH for free and immobilized pectinase remained unchanged at 50°C and pH 4. Thermostability, reaction stability and reusability of two ultrasound-treated pectinase enzymes slightly decreased due to structural matrix changes. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

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.

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.

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).

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.

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.

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).

Ceramic membrane microfilter as an immobilized enzyme reactor.

PubMed

Harrington, T J; Gainer, J L; Kirwan, D J

1992-10-01

This study investigated the use of a ceramic microfilter as an immobilized enzyme reactor. In this type of reactor, the substrate solution permeates the ceramic membrane and reacts with an enzyme that has been immobilized within its porous interior. The objective of this study was to examine the effect of permeation rate on the observed kinetic parameters for the immobilized enzyme in order to assess possible mass transfer influences or shear effects. Kinetic parameters were found to be independent of flow rate for immobilized penicillinase and lactate dehydrogenase. Therefore, neither mass transfer nor shear effects were observed for enzymes immobilized within the ceramic membrane. Both the residence time and the conversion in the microfilter reactor could be controlled simply by regulating the transmembrane pressure drop. This study suggests that a ceramic microfilter reactor can be a desirable alternative to a packed bed of porous particles, especially when an immobilized enzyme has high activity and a low Michaelis constant.

Using Computers for Intervention and Remediation of Severely Reading-Impaired Children in a University Literacy Clinic.

ERIC Educational Resources Information Center

Balajthy, Ernest; Reuber, Kristin; Damon, Corrine J.

A study investigated software choices of graduate-level clinicians in a university reading clinic to determine computer use and effectiveness in literacy instruction. The clinic involved students of varying ability, ages 7-12, using 24 Power Macintosh computers equipped with "ClarisWorks,""Kid Pix,""Student Writing…

Preliminary application of tapered glass capillary microbeam in MeV-PIXE mapping of longan leaf for elemental concentration distribution analysis

NASA Astrophysics Data System (ADS)

Natyanun, S.; Unai, S.; Yu, L. D.; Tippawan, U.; Pussadee, N.

2017-09-01

This study was aimed at understanding elemental concentration distribution in local longan leaf for how the plant was affected by the environment or agricultural operation. The analysis applied the MeV-microbeam particle induced X-ray emission (PIXE) mapping technique using a home-developed tapered glass capillary microbeam system at Chiang Mai University. The microbeam was 2-MeV proton beam in 130 µm in diameter. The studying interest was in the difference in the elemental concentrations distributed between the leaf midrib and lamina areas. The micro proton beam analyzed the leaf sample across the leaf midrib edge to the leaf lamina area for total 9 data requisition spots. The resulting data were colored to form a 1D-map of the elemental concentration distribution. Seven dominant elements, Al, S, Cl, K, Ca, Sc and Fe, were identified, the first six of which were found having higher concentrations in the midrib area than in the lamina area, while the Fe concentration was in an opposite trend to that of the others.

Böttger stoneware from North America and Europe; are they authentic

NASA Astrophysics Data System (ADS)

Swann, Charles P.; Nelson, Christina H.

2000-03-01

In the early 18th century, Johann Friedrich Böttger, an alchemist recently arrived in Dresden, was assigned to ceramic experimentation under the orders of Augustus the Strong, Elector of Saxony and King of Poland. The Elector and his advisors hoped to discover the secret of making hard paste porcelain like the wares imported into Europe from China and Japan. In 1706-1707, Böttger produced his first ceramic body, a red stoneware similar to the wares produced in Yixing, China. The first objects were made following the forms of chinese prototypes or European metalwork of the period. Recently, the authenticity of a number of `Böttger' objects in various museums and private collections in North America and Europe has been questioned. To aide in resolving these questions several non-destructive analytical techniques have been employed, the most important being PIXE. This report is on an initial study of 25 objects with 16 elements from Al to Zr and Pb being analysed. The results strongly suggest three different groupings, one of objects from the Meissen factory during the 20th century, one from the work of Böttger himself early in the 18th century and one from an as yet unknown time period and site. The first two groups were previously identified by one of the authors (C.N.).

A sensitive label–free amperometric immunosensor for alpha-fetoprotein based on gold nanorods with different aspect ratio

PubMed Central

Zhou, Chunyang; Liu, Dali; Xu, Lin; Li, Qingling; Song, Jian; Xu, Sai; Xing, Ruiqing; Song, Hongwei

2015-01-01

A simple and accurate label–free amperometric immunosensor for α–fetoprotein (AFP) detection is developed based on gold nanorods (GNRs) with different aspect ratio and compared with gold particles (GNPs). The positively charged GNRs and GNPs due to the surface immobilized cetyltrimethyl ammonium bromide (CTAB) can adsorb the negatively charged AFP antibody (Ab) directly. The presence of the GNRs not only enhanced the immobilized amount of biomolecules, but also improved the electrochemical properties of the immunosensor. With the aid of GNRs, the electrochemical signal was greatly enhanced in comparison with GNPs. Under optimal conditions, the proposed immunosensor could detect AFP in a linear range from 0.1 to 200 ng/mL with a detection limit of 0.04 ng/mL (signal–to–noise ratio = 3), and it also possessed good reproducibility and storage stability. Moreover, the detection of AFP in five human serum samples also showed satisfactory accuracy. The proposed methodology was potentially attractive for clinical immunoassay. PMID:25909588

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.

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.

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.

SU-E-J-231: Comparison of Delineation Variability of Soft Tissue Volume and Position in Head-And-Neck Between Two T1-Weighted Pulse Sequences Using An MR-Simulator with Immobilization

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

Wong, O; Lo, G; Yuan, J

Purpose: There is growing interests in applying MR-simulator(MR-sim) in radiotherapy but MR images subject to hardware, patient and pulse sequence dependent geometric distortion that may potentially influence target definition. This study aimed to evaluate the influence on head-and-neck tissue delineation, in terms of positional and volumetric variability, of two T1-weighted(T1w) MR sequences on a 1.5T MR-sim Methods: Four healthy volunteers were scanned (4 scans for each on different days) using both spin-echo (3DCUBE, TR/TE=500/14ms, TA=183s) and gradient-echo sequences (3DFSPGR, TE/TR=7/4ms, TA=173s) with identical coverage, voxel-size(0.8×0.8×1.0mm3), receiver-bandwidth(62.5kHz/pix) and geometric correction on a 1.5T MR-sim immobilized with personalized thermoplastic cast and head-rest.more » Under this setting, similar T1w contrast and signal-to-noise ratio were obtained, and factors other than sequence that might bias image distortion and tissue delineation were minimized. VOIs of parotid gland(PGR, PGL), pituitary gland(PIT) and eyeballs(EyeL, EyeR) were carefully drawn, and inter-scan coefficient-of-variation(CV) of VOI centroid position and volume were calculated for each subject. Mean and standard deviation(SD) of the CVs for four subjects were compared between sequences using Wilcoxon ranksum test. Results: The mean positional(<4%) and volumetric(<7%) CVs varied between tissues, majorly dependent on tissue inherent properties like volume, location, mobility and deformability. Smaller mean volumetric CV was found in 3DCUBE, probably due to its less proneness to tissue susceptibility, but only PGL showed significant difference(P<0.05). Positional CVs had no significant differences for all VOIs(P>0.05) between sequences, suggesting volumetric variation might be more sensitive to sequence-dependent delineation difference. Conclusion: Although 3DCUBE is considered less prone to tissue susceptibility-induced artifact and distortion, our preliminary data showed that both sequences had insignificant differences on positional and volumetric CV in most head-and-neck tissues except for PGL. This study is majorly limited in its small sample size. Influences of image contrasts(T1w v.s. T2w) and inter-observer difference have to be further investigated.« less

Determination of conformation and orientation of immobilized peptides and proteins at buried interfaces

NASA Astrophysics Data System (ADS)

Shen, Lei; Ulrich, Nathan W.; Mello, Charlene M.; Chen, Zhan

2015-01-01

Surface immobilized peptides/proteins have important applications such as antimicrobial coating and biosensing. We report a study of such peptides/proteins using sum frequency generation vibrational spectroscopy and ATR-FTIR. Immobilization on surfaces via physical adsorption and chemical coupling revealed that structures of chemically immobilized peptides are determined by immobilization sites, chemical environments, and substrate surfaces. In addition, controlling enzyme orientation by engineering the surface immobilization site demonstrated that structures can be well-correlated to measured chemical activity. This research facilitates the development of immobilized peptides/proteins with improved activities by optimizing their surface orientation and structure.

Immobilization in External Rotation Versus Internal Rotation After Primary Anterior Shoulder Dislocation: A Meta-analysis of Randomized Controlled Trials.

PubMed

Whelan, Daniel B; Kletke, Stephanie N; Schemitsch, Geoffrey; Chahal, Jaskarndip

2016-02-01

The recurrence rate after primary anterior shoulder dislocation is high, especially in young, active individuals. Recent studies have suggested external rotation immobilization as a method to reduce the rate of recurrent shoulder dislocation in comparison to traditional sling immobilization. To assess and summarize evidence from randomized controlled trials on the effect of internal rotation versus external rotation immobilization on the rate of recurrence after primary anterior shoulder dislocation. Meta-analysis. PubMed, MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, and abstracts from recent proceedings were searched for eligible studies. Two reviewers selected studies for inclusion, assessed methodological quality, and extracted data. Six randomized controlled trials (632 patients) were included in this review. Demographic and prognostic variables measured at baseline were similar in the pooled groups. The average age was 30.1 years in the pooled external rotation group and 30.3 years in the pooled internal rotation group. Two studies found that external rotation immobilization reduced the rate of recurrence after initial anterior shoulder dislocation compared with conventional internal rotation immobilization, whereas 4 studies failed to find a significant difference between the 2 groups. This meta-analysis suggested no overall significant difference in the rate of recurrence among patients treated with internal rotation versus external rotation immobilization (risk ratio, 0.69; 95% CI, 0.42-1.14; P = .15). There was no significant difference in the rate of compliance between internal and external rotation immobilization (P = .43). The Western Ontario Shoulder Instability Index scores were pooled across 3 studies, and there was no significant difference between the 2 groups (P = .54). Immobilization in external rotation is not significantly more effective in reducing the recurrence rate after primary anterior shoulder dislocation than immobilization in internal rotation. Additionally, this review suggests that there is minimal difference in patients' perceptions of their health-related quality of life after immobilization in internal versus external rotation. © 2015 The Author(s).

Trace elements in human alveolar macrophages studied by PIXE

NASA Astrophysics Data System (ADS)

Weber, G.; Roelandts, I.; Corhay, J. L.; Radermecker, M.; Delavignette, J. P.

1990-04-01

The purpose of this study is to determine the metal content of alveolar macrophages by PIXE from 94 subjects divided into two groups as follows: group (1) — subjects with non-occupational exposure to industrial dust: 30 healthy volunteers (controls), 16 patients suffering from lung cancer; group (2) — 48 healthy steel workers from the Liège area (blast-furnace [ n=29] and coke oven [ n=19]). We hope to define more precisely the influence of carcinoma, smoking habit, pathology and occupational exposure in the steel industry on the macrophage metal content. This study has shown: (a) an Fe and Sr increase and a Br decrease in the macrophages of smokers (especially in heavy smokers): (b) a significant Fe, Ti, Br and Cu increase and a trend to Pb, Cr, As and Sr increase in macrophages of healthy steel workers (especially blast-furnace workers) in comparison with non-exposed controls; (c) a significant Fe, Br, Cu and Zn increase and a trend to Pb, As and Ni increase in macrophages of non-exposed patients with lung cancer by comparison with non-exposed controls. The mechanism of metal change could be explained by professional exposure and endogenous changes (protein synthesis, inflammation, bronchial bleeding, …)

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.

Immobilization of an L-aminoacylase-producing strain of Aspergillus oryzae into gelatin pellets and its application in the resolution of D,L-methionine.

PubMed

Yuan Yj, Ying-jin; Wang Sh, Shu-hao; Song Zx, Zheng-xiao; Gao Rc, Rui-chang

2002-04-01

The conditions for immobilization of an l-aminoacylase-producing strain of Aspergillus oryzae in gelatin and the enzymic characteristics of the immobilized pellets were studied. The optimal concentrations of gelatin, glutaraldehyde and ethyldiamine and time of immobilization were determined. Scanning electron micrographs reveal the cross-linked structure differences between the native and immobilized pellets. Optimum pH and temperature of the native and immobilized pellets were determined. Effects of ionic strength and substrate concentration on relative activity of the native and immobilized pellets were investigated in detail. The immobilized pellets were more stable over broader temperature and pH ranges. In addition, the immobilized pellets showed stable activity under operational and storage conditions. The immobilized pellets lost about 20% of their initial activity after five cycles of reuse. The results reported in this paper show the potential for using the immobilized A. oryzae pellets to resolve d,l-methionine.

Puncture mechanics of cnidarian cnidocysts: a natural actuator

PubMed Central

Oppegard, Shawn C; Anderson, Peter A; Eddington, David T

2009-01-01

Background Cnidocysts isolated from cnidarian organisms are attractive as a drug-delivery platform due to their fast, efficient delivery of toxins. The cnidocyst could be utilized as the means to deliver therapeutics in a wearable drug-delivery patch. Cnidocysts have been previously shown to discharge upon stimulation via electrical, mechanical, and chemical pathways. Cnidocysts isolated from the Portuguese Man O' War jellyfish (Physalia physalis) are attractive for this purpose because they possess relatively long threads, are capable of puncturing through hard fish scales, and are stable for years. Results As a first step in using cnidocysts as a functional component of a drug delivery system, the puncture mechanics of the thread were characterized. Tentacle-contained cnidocysts were used as a best-case scenario due to physical immobilization of the cnidocysts within the tentacle. Ex vivo tentacle-contained cnidocysts from Physalia possessed an elastic modulus puncture threshold of approximately 1-2 MPa, based on puncture tests of materials with a gamut of hardness. Also, a method for inducing discharge of isolated cnidocysts was found, utilizing water as the stimulant. Preliminary lectin-binding experiments were performed using fluorophore-conjugated lectins as a possible means to immobilize the isolated cnidocyst capsule, and prevent reorientation upon triggering. Lectins bound homogeneously to the surface of the capsule, suggesting the lectins could be used for cnidocyst immobilization but not orientation. Conclusion Cnidocysts were found to puncture materials up to 1 MPa in hardness, can be discharged in a dry state using water as a stimulant, and bind homogeneously to lectins, a potential means of immobilization. The information gained from this preliminary work will aid in determining the materials and design of the patch that could be used for drug delivery. PMID:19785761

The Capodimonte Deep Field

NASA Astrophysics Data System (ADS)

2001-04-01

A Window towards the Distant Universe Summary The Osservatorio Astronomico Capodimonte Deep Field (OACDF) is a multi-colour imaging survey project that is opening a new window towards the distant universe. It is conducted with the ESO Wide Field Imager (WFI) , a 67-million pixel advanced camera attached to the MPG/ESO 2.2-m telescope at the La Silla Observatory (Chile). As a pilot project at the Osservatorio Astronomico di Capodimonte (OAC) [1], the OACDF aims at providing a large photometric database for deep extragalactic studies, with important by-products for galactic and planetary research. Moreover, it also serves to gather experience in the proper and efficient handling of very large data sets, preparing for the arrival of the VLT Survey Telescope (VST) with the 1 x 1 degree 2 OmegaCam facility. PR Photo 15a/01 : Colour composite of the OACDF2 field . PR Photo 15b/01 : Interacting galaxies in the OACDF2 field. PR Photo 15c/01 : Spiral galaxy and nebulous object in the OACDF2 field. PR Photo 15d/01 : A galaxy cluster in the OACDF2 field. PR Photo 15e/01 : Another galaxy cluster in the OACDF2 field. PR Photo 15f/01 : An elliptical galaxy in the OACDF2 field. The Capodimonte Deep Field ESO PR Photo 15a/01 ESO PR Photo 15a/01 [Preview - JPEG: 400 x 426 pix - 73k] [Normal - JPEG: 800 x 851 pix - 736k] [Hi-Res - JPEG: 3000 x 3190 pix - 7.3M] Caption : This three-colour image of about 1/4 of the Capodimonte Deep Field (OACDF) was obtained with the Wide-Field Imager (WFI) on the MPG/ESO 2.2-m telescope at the la Silla Observatory. It covers "OACDF Subfield no. 2 (OACDF2)" with an area of about 35 x 32 arcmin 2 (about the size of the full moon), and it is one of the "deepest" wide-field images ever obtained. Technical information about this photo is available below. With the comparatively few large telescopes available in the world, it is not possible to study the Universe to its outmost limits in all directions. Instead, astronomers try to obtain the most detailed information possible in selected viewing directions, assuming that what they find there is representative for the Universe as a whole. This is the philosophy behind the so-called "deep-field" projects that subject small areas of the sky to intensive observations with different telescopes and methods. The astronomers determine the properties of the objects seen, as well as their distances and are then able to obtain a map of the space within the corresponding cone-of-view (the "pencil beam"). Recent, successful examples of this technique are the "Hubble Deep Field" (cf. ESO PR Photo 26/98 ) and the "Chandra Deep Field" ( ESO PR 05/01 ). In this context, the Capodimonte Deep Field (OACDF) is a pilot research project, now underway at the Osservatorio Astronomico di Capodimonte (OAC) in Napoli (Italy). It is a multi-colour imaging survey performed with the Wide Field Imager (WFI) , a 67-million pixel (8k x 8k) digital camera that is installed at the 2.2-m MPG/ESO Telescope at ESO's La Silla Observatory in Chile. The scientific goal of the OACDF is to provide an important database for subsequent extragalactic, galactic and planetary studies. It will allow the astronomers at OAC - who are involved in the VLT Survey Telescope (VST) project - to gain insight into the processing (and use) of the large data flow from a camera similar to, but four times smaller than the OmegaCam wide-field camera that will be installed at the VST. The field selection for the OACDF was based on the following criteria: * There must be no stars brighter than about 9th magnitude in the field, in order to avoid saturation of the CCD detector and effects from straylight in the telescope and camera. No Solar System planets should be near the field during the observations; * It must be located far from the Milky Way plane (at high galactic latitude) in order to reduce the number of galactic stars seen in this direction; * It must be located in the southern sky in order to optimize observing conditions (in particular, the altitude of the field above the horizon), as seen from the La Silla and Paranal sites; * There should be little interstellar material in this direction that may obscure the view towards the distant Universe; * Observations in this field should have been made with the Hubble Space Telescope (HST) that may serve for comparison and calibration purposes. Based on these criteria, the astronomers selected a field measuring about 1 x 1 deg 2 in the southern constellation of Corvus (The Raven). This is now known as the Capodimonte Deep Field (OACDF) . The above photo ( PR Photo 15a/01 ) covers one-quarter of the full field (Subfield No. 2 - OACDF2) - some of the objects seen in this area are shown below in more detail. More than 35,000 objects have been found in this area; the faintest are nearly 100 million fainter than what can be perceived with the unaided eye in the dark sky. Selected objects in the Capodimonte Deep Field ESO PR Photo 15b/01 ESO PR Photo 15b/01 [Preview - JPEG: 400 x 435 pix - 60k] [Normal - JPEG: 800 x 870 pix - 738k] [Hi-Res - JPEG: 3000 x 3261 pix - 5.1M] Caption : Enlargement of the interacting galaxies that are seen in the upper left corner of the OACDF2 field shown in PR Photo 15a/01 . The enlargement covers 1250 x 1130 WFI pixels (1 pixel = 0.24 arcsec), or about 5.0 x 4.5 arcmin 2 in the sky. The lower spiral is itself an interactive double. ESO PR Photo 15c/01 ESO PR Photo 15c/01 [Preview - JPEG: 557 x 400 pix - 93k] [Normal - JPEG: 1113 x 800 pix - 937k] [Hi-Res - JPEG: 3000 x 2156 pix - 4.0M] Caption : Enlargement of a spiral galaxy and a nebulous object in this area. The field shown covers 1250 x 750 pixels, or about 5 x 3 arcmin 2 in the sky. Note the very red objects next to the two bright stars in the lower-right corner. The colours of these objects are consistent with those of spheroidal galaxies at intermediate distances (redshifts). ESO PR Photo 15d/01 ESO PR Photo 15d/01 [Preview - JPEG: 400 x 530 pix - 68k] [Normal - JPEG: 800 x 1060 pix - 870k] [Hi-Res - JPEG: 2768 x 3668 pix - 6.2M] Caption : A further enlargement of a galaxy cluster of which most members are located in the north-east quadrant (upper left) and have a reddish colour. The nebulous object to the upper left is a dwarf galaxy of spheroidal shape. The red object, located near the centre of the field and resembling a double star, is very likely a gravitational lens [2]. Some of the very red, point-like objects in the field may be distant quasars, very-low mass stars or, possibly, relatively nearby brown dwarf stars. The field shown covers 1380 x 1630 pixels, or 5.5 x 6.5 arcmin 2. ESO PR Photo 15e/01 ESO PR Photo 15e/01 [Preview - JPEG: 400 x 418 pix - 56k] [Normal - JPEG: 800 x 835 pix - 700k] [Hi-Res - JPEG: 3000 x 3131 pix - 5.0M] Caption : Enlargement of a moderately distant galaxy cluster in the south-east quadrant (lower left) of the OACDF2 field. The field measures 1380 x 1260 pixels, or about 5.5 x 5.0 arcmin 2 in the sky. ESO PR Photo 15f/01 ESO PR Photo 15f/01 [Preview - JPEG: 449 x 400 pix - 68k] [Normal - JPEG: 897 x 800 pix - 799k] [Hi-Res - JPEG: 3000 x 2675 pix - 5.6M] Caption : Enlargement of the elliptical galaxy that is located to the west (right) in the OACDF2 field. The numerous tiny objects surrounding the galaxy may be globular clusters. The fuzzy object on the right edge of the field may be a dwarf spheroidal galaxy. The size of the field is about 6 x 5 arcmin 2. Technical Information about the OACDF Survey The observations for the OACDF project were performed in three different ESO periods (18-22 April 1999, 7-12 March 2000 and 26-30 April 2000). Some 100 Gbyte of raw data were collected during each of the three observing runs. The first OACDF run was done just after the commissioning of the ESO-WFI. The observational strategy was to perform a 1 x 1 deg 2 short-exposure ("shallow") survey and then a 0.5 x 1 deg 2 "deep" survey. The shallow survey was performed in the B, V, R and I broad-band filters. Four adjacent 30 x 30 arcmin 2 fields, together covering a 1 x 1 deg 2 field in the sky, were observed for the shallow survey. Two of these fields were chosen for the 0.5 x 1 deg 2 deep survey; OACDF2 shown above is one of these. The deep survey was performed in the B, V, R broad-bands and in other intermediate-band filters. The OACDF data are fully reduced and the catalogue extraction has started. A two-processor (500 Mhz each) DS20 machine with 100 Gbyte of hard disk, specifically acquired at the OAC for WFI data reduction, was used. The detailed guidelines of the data reduction, as well as the catalogue extraction, are reported in a research paper that will appear in the European research journal Astronomy & Astrophysics . Notes [1]: The team members are: Massimo Capaccioli, Juan M. Alcala', Roberto Silvotti, Magda Arnaboldi, Vincenzo Ripepi, Emanuella Puddu, Massimo Dall'Ora, Giuseppe Longo and Roberto Scaramella . [2]: This is a preliminary result by Juan Alcala', Massimo Capaccioli, Giuseppe Longo, Mikhail Sazhin, Roberto Silvotti and Vincenzo Testa , based on recent observations with the Telescopio Nazionale Galileo (TNG) which show that the spectra of the two objects are identical. Technical information about the photos PR Photo 15a/01 has been obtained by the combination of the B, V, and R stacked images of the OACDF2 field. The total exposure times in the three bands are 2 hours in B and V (12 ditherings of 10 min each were stacked to produce the B and V images) and 3 hours in R (13 ditherings of 15 min each). The mosaic images in the B and V bands were aligned relative to the R-band image and adjusted to a logarithmic intensity scale prior to the combination. The typical seeing was of the order of 1 arcsec in each of the three bands. Preliminary estimates of the three-sigma limiting magnitudes in B, V and R indicate 25.5, 25.0 and 25.0, respectively. More than 35,000 objects are detected above the three-sigma level. PR Photos 15b-f/01 display selected areas of the field shown in PR Photo 15a/01 at the original WFI scale, hereby also demonstrating the enormous amount of information contained in these wide-field images. In all photos, North is up and East is left.

Potential negative consequences of adding phosphorus-based fertilizers to immobilize lead in soil

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

Kilgour, Douglas W.; Moseley, Rebecca A.; Savage, Kaye S

2008-09-01

A study of the potential negative consequences of adding phosphate (P)-based fertilizers as amendments to immobilize lead (Pb) in contaminated soils was conducted. Lead-contaminated firing range soils also contained elevated concentrations of antimony (Sb), a common Pb hardening agent, and some arsenic (As) of unknown (possibly background) origin. After amending the soils with triple superphosphate, a relatively soluble P source, column leaching experiments revealed elevated concentrations of Sb, As, and Pb in the leachate, reflecting an initial spike in soluble Pb and a particularly dramatic increase in Sb and As mobility. Minimal As, Sb, and Pb leaching was observed duringmore » column tests performed on non-amended control soils. In vitro extractions tests were performed to assess changes in Pb, As, and Sb bioaccessibility on P amendment. Lead bioaccessibility was systematically lowered with increasing P dosage, but there was much less of an effect on As and Sb bioaccessibility than on mobility. Our results indicate that although P amendments may aid in lowering the bioaccessibility of soil-bound Pb, it may also produce an initial increase in Pb mobility and a significant release of Sb and As from the soil, dramatically increasing their mobility and to a lesser extent their bioavailability.« less

Kinetic study of Candida antarctica lipase B immobilization using poly(methyl methacrylate) nanoparticles obtained by miniemulsion polymerization as support.

PubMed

Valério, Alexsandra; Nicoletti, Gabrieli; Cipolatti, Eliane P; Ninow, Jorge L; Araújo, Pedro H H; Sayer, Cláudia; de Oliveira, Débora

2015-03-01

With the objective to obtain immobilized Candida antarctica lipase B (CalB) with good activity and improved utilization rate, this study evaluated the influence of enzyme and crodamol concentrations and initiator type on the CalB enzyme immobilization in nanoparticles consisting of poly(methyl methacrylate) (PMMA) obtained by miniemulsion polymerization. The kinetic study of immobilized CalB enzyme in PMMA nanoparticles was evaluated in terms of monomer conversion, particle size, zeta potential, and relative activity. The optimum immobilization condition for CalB was compared with free enzyme in the p-NPL hydrolysis activity measurement. Results showed a higher CalB enzyme stability after 20 hydrolysis cycles compared with free CalB enzyme; in particular, the relative immobilized enzyme activity was maintained up to 40%. In conclusion, PMMA nanoparticles proved to be a good support for the CalB enzyme immobilization and may be used as a feasible alternative catalyst in industrial processes.

Quantitative mapping of elemental distribution in leaves of the metallophytes Helichrysum candolleanum, Blepharis aspera, and Blepharis diversispina from Selkirk Cu-Ni mine, Botswana

NASA Astrophysics Data System (ADS)

Koosaletse-Mswela, Pulane; Przybyłowicz, Wojciech J.; Cloete, Karen J.; Barnabas, Alban D.; Torto, Nelson; Mesjasz-Przybyłowicz, Jolanta

2015-11-01

Multi-element profiling is essential in understanding the metal-tolerant behavior of metallophytes. Although previous reports using multi-elemental analyses show that the metallophytes Blepharis aspera, Blepharis diversispina (Acanthaceae) and Helichrysum candolleanum (Asteraceae) take up metals, no information exists on elemental spatial distribution and concentrations in specific tissues of these plants. The aim of this study therefore was to assess the spatial distribution and concentration of copper, nickel and other elements in leaf tissues of these plants using micro-PIXE. Whole plants were collected with soil in pots from an operational copper and nickel mine (i.e., a copper and nickel mineralized area), Selkirk, about 40 km north-east of Francistown, Botswana. On the same day the samples were transported by air to iThemba LABS in South Africa. Leaf specimens were cryofixed in liquid propane cooled by LN2. Parallel samples were embedded in resin for anatomical studies to facilitate interpretation of elemental maps. The distribution and concentration of copper, nickel, and other elements in leaf tissues were determined using micro-PIXE and proton backscattering spectrometry. Data evaluation was performed using GeoPIXE II software. Micro-PIXE showed that H. candolleanum had the highest whole leaf content of copper (70 ± 3 μg g-1 DW) and nickel (168 ± 5 μg g-1 DW), followed by B. aspera (Cu: 25 ± 1 μg g-1 DW; Ni: 166 ± 4 μg g-1 DW) and B. diversispina (Cu: 3 ± 1 μg g-1 DW; Ni, below detection limit). For specific leaf tissues, the highest levels of copper were found in the vascular bundle for H. candolleanum (167 ± 7 μg g-1 DW) and the lower epidermis for B. aspera (70 ± 9 μg g-1 DW). The highest levels of nickel were present in the vascular bundle of B. aspera (479 ± 10 μg g-1 DW) and H. candolleanum (90 ± 5 μg g-1 DW). Elemental maps showed a similar distribution pattern for copper and nickel in B. aspera and B diversispina, with these elements concentrated in the upper and lower epidermal regions. However, for H. candolleanum, both copper and nickel were concentrated in the mesophyll. The difference in concentration and accumulation patterns between B. aspera, B. diversispina and H. candolleanum suggests that the metal-tolerant adaptation of these metallophytes may differ.

Amperometric immunosensor for α-fetoprotein antigen in human serum based on co-immobilizing dinuclear copper complex and gold nanoparticle doped chitosan film

NASA Astrophysics Data System (ADS)

Gan, Ning; Meng, Ling Hua; Wang, Feng

2009-09-01

A sensitive amperometric immunosensor for α-fetoprotein (AFP), a tumor marker for the diagnosis of hepatocellular carcinoma (HCC), was constructed, The immunosensor is prepared by co-immobilizing [Cu2(phen)2Cl2] (μ-Cl)2 (CuL), nano-Au/Chitosan(Chit) composite, horseradish peroxidase (HRP) and AFP antibody(anti-AFP) on a glassy carbon electrode (GCE). Firstly, CuL was irreversibly absorb on GCE electrode through π-π stacking interaction; then nano-Au/Chit composite was immobilized onto the electrode because of its excellent membrane-forming ability, finally HRP and anti-AFP was adsorbed onto the surface of the gold nanoparticles to construct GCE | CuL/nanoAu-chit/HRP/anti-AFP immunosensor. The preparation procedure of the electrode was characterized by electrochemical and spectroscopy method. The results showed that this immunosensor exhibited an excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2) without the aid of an electron mediator, offers a high-sensitivity (1710 nA · ng-1 · ml-1) for the detection of AFP and has good correlation for detection of AFP in the range of 0.2 to 120.0 ng/ml with a detection limit of 0.05 ng/ml. The biosensor showed high selectivity as well as good stability and reproductivity.

Study of Italian Renaissance sculptures using an external beam nuclear microprobe

NASA Astrophysics Data System (ADS)

Zucchiatti, A.; Bouquillon, A.; Moignard, B.; Salomon, J.; Gaborit, J. R.

2000-03-01

The use of an extracted proton micro-beam for the PIXE analysis of glazes is discussed in the context of the growing interest in the creation of an analytical database on Italian Renaissance glazed terracotta sculptures. Some results concerning the frieze of an altarpiece of the Louvre museum, featuring white angels and cherubs heads, are presented.

Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase from Aspergillus niger on β-Cyclodextrin-Fe3O4 Nanoparticles and Ionic Liquid

PubMed Central

Huang, Po-Jung; Chang, Ken-Lin; Chen, Shui-Tein

2015-01-01

Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1 at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase. PMID:25874210

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).

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.

Nuclear and atomic analytical techniques in environmental studies in South America.

PubMed

Paschoa, A S

1990-01-01

The use of nuclear analytical techniques for environmental studies in South America is selectively reviewed since the time of earlier works of Lattes with cosmic rays until the recent applications of the PIXE (particle-induced X-ray emission) technique to study air pollution problems in large cities, such as São Paulo and Rio de Janeiro. The studies on natural radioactivity and fallout from nuclear weapons in South America are briefly examined.

Potential immobilized Saccharomyces cerevisiae as heavy metal removal

NASA Astrophysics Data System (ADS)

Raffar, Nur Izzati Abdul; Rahman, Nadhratul Nur Ain Abdul; Alrozi, Rasyidah; Senusi, Faraziehan; Chang, Siu Hua

2015-05-01

Biosorption of copper ion using treated and untreated immobilized Saccharomyces cerevisiae from aqueous solution was investigate in this study. S.cerevisiae has been choosing as biosorbent due to low cost, easy and continuously available from various industries. In this study, the ability of treated and untreated immobilized S.cerevisiae in removing copper ion influence by the effect of pH solution, and initial concentration of copper ion with contact time. Besides, adsorption isotherm and kinetic model also studied. The result indicated that the copper ion uptake on treated and untreated immobilized S.cerevisiae was increased with increasing of contact time and initial concentration of copper ion. The optimum pH for copper ion uptake on untreated and treated immobilized S.cerevisiae at 4 and 6. From the data obtained of copper ion uptake, the adsorption isotherm was fitted well by Freundlich model for treated immobilized S.cerevisiae and Langmuir model for untreated immobilized S.cerevisiae according to high correlation coefficient. Meanwhile, the pseudo second order was described as suitable model present according to high correlation coefficient. Since the application of biosorption process has been received more attention from numerous researchers as a potential process to be applied in the industry, future study will be conducted to investigate the potential of immobilized S.cerevisiae in continuous process.

Reconstruction of a Severely Atrophied Alveolar Ridge by Computer-Aided Gingival Simulation and 3D-Printed Surgical Guide: A Case Report.

PubMed

Song, In-Seok; Lee, Mi-Ran; Ryu, Jae-Jun; Lee, Ui-Lyong

Dental implants positioned in severely atrophied anterior maxillae require esthetic or functional compromises. This case report describes the rehabilitation of a severely atrophied alveolar ridge with a three-dimensional (3D) computer-aided design/computer-aided manufacture (CAD/CAM) surgical guide. A 50-year-old woman had a severely atrophied anterior maxilla with unfavorably positioned dental implants. Functional and esthetic prosthodontic restoration was difficult to achieve. An anterior segmental osteotomy was planned to reposition the dental implants. A 3D surgical guide was designed for precise relocation of the segment. The surgical guide firmly grasped the impression copings of the dental implants, minimizing surgical errors. Three-dimensional gingival simulation was used preoperatively to estimate the appropriate position of the gingiva. Rigid fixation to the surrounding bone allowed immobilization of the implant-bone segment. Satisfactory esthetic and functional outcomes were attained 6 months after surgery. Finally, a severely atrophied alveolar ridge with unfavorably positioned dental implants was recovered with minimal esthetic and functional deterioration using gingival simulation and a 3D CAD/CAM surgical guide.

Immobilization of Cr (VI) in stainless steel slag and Cd, As, and Pb in wastewater using blast furnace slag via a hydrothermal treatment

NASA Astrophysics Data System (ADS)

Tae, Soon-Jae; Morita, Kazuki

2017-05-01

The immobilization of hexavalent chromium in stainless steel slag using blast furnace slag as the immobilizing agent and by performing a hydrothermal treatment was investigated. The results showed that there was no immobilization in the absence of the blast furnace slag. On the other hand, the hexavalent chromium in stainless steel slag could be immobilized through the hydrothermal reaction when blast furnace slag was used at 250 °C for 24 h. A leaching test was performed to evaluate the degree of immobilization of hexavalent chromium in the products formed by the hydrothermal reaction. It was found that the degree of immobilization was very high. Based on the results obtained, the immobilization mechanism of hexavalent chromium in stainless steel slag, resulting from the hydrothermal treatment of blast furnace slag, could be elucidated. Finally, the immobilization of cadmium, lead, and arsenic using blast furnace slag as the immobilization agent was also studied while focusing on the effects of the hydrothermal treatment.

Complementary microanalysis of Zn, Mn and Fe in the chelicera of spiders and scorpions using scanning MeV-ion and electron microprobes

NASA Astrophysics Data System (ADS)

Schofield, Robert; Lefevre, Harlan; Shaffer, Michael

1989-04-01

Energy-loss scanning transmission ion microscopy (ELSTIM or just STIM), PIXE and electron microprobe techniques are used to investigate certain minor element accumulations in a few spiders and scorpions. STIM and PIXE are used to survey the unsectioned specimens, while electron microprobe techniques are used for higher resolution investigations of several sections of the specimens. Concentration values measured using STIM and PIXE are found to be in satisfactory agreement with those measured using electron probe microanalysis. A garden spider Araneus diadematus is found to contain high concentrations of zinc in a thin layer near the surface of its fangs (reaching 23% of dry weight), and manganese in its marginal teeth (about 5% of dry weight). A wolf spider Alopecosa kochi is found to have similar concentrations of zinc in a layer near the surface of it's fang, and concentrations of manganese reaching 1.5% in a layer beneath the zinc containing layer. A scorpion Centruroides sp. is found to contain high concentrations of iron (reaching 8%) and zinc (reaching 24%) in the tips of teeth on the cheliceral fingers, and manganese (about 5%) in the stinger. The hypothesis that these elements simply harden the cuticle does not appear to explain their segregation patterns.

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.

PFM2: a 32 × 32 processor for X-ray diffraction imaging at FELs

NASA Astrophysics Data System (ADS)

Manghisoni, M.; Fabris, L.; Re, V.; Traversi, G.; Ratti, L.; Grassi, M.; Lodola, L.; Malcovati, P.; Vacchi, C.; Pancheri, L.; Benkechcache, M. E. A.; Dalla Betta, G.-F.; Xu, H.; Verzellesi, G.; Ronchin, S.; Boscardin, M.; Batignani, G.; Bettarini, S.; Casarosa, G.; Forti, F.; Giorgi, M.; Paladino, A.; Paoloni, E.; Rizzo, G.; Morsani, F.

2016-11-01

This work is concerned with the design of a readout chip for application to experiments at the next generation X-ray Free Electron Lasers (FEL). The ASIC, named PixFEL Matrix (PFM2), has been designed in a 65 nm CMOS technology and consists of 32 × 32 pixels. Each cell covers an area of 110 × 110 μm2 and includes a low-noise charge sensitive amplifier (CSA) with dynamic signal compression, a time-variant shaper used to process the preamplifier output signal, a 10-bit successive approximation register (SAR) analog-to-digital converter (ADC) and digital circuitry for channel control and data readout. Two different solutions for the readout channel, based on different versions of the time-variant filter, have been integrated in the chip. Both solutions can be operated in such a way to cope with the high frame rate (exceeding 1 MHz) foreseen for future X-ray FEL machines. The ASIC will be bump bonded to a slim/active edge pixel sensor to form the first demonstrator for the PixFEL X-ray imager. This work has been carried out in the frame of the PixFEL project funded by Istituto Nazionale di Fisica Nucleare (INFN), Italy.

Effect of kinesthetic illusion induced by visual stimulation on muscular output function after short-term immobilization.

PubMed

Inada, Toru; Kaneko, Fuminari; Hayami, Tatsuya

2016-04-01

Kinesthetic illusions by visual stimulation (KiNVIS) enhances corticomotor excitability and activates motor association areas. The purpose of this study was to investigate the effect of KiNVIS induction on muscular output function after short-term immobilization. Thirty subjects were assigned to 3 groups: an immobilization group, with the left hand immobilized for 12h (immobilization period); an illusion group, with the left hand immobilized and additionally subjected to KiNVIS of the immobilized part during the immobilization period; and a control group with no manipulation. The maximum voluntary contraction (MVC), fluctuation of force (force fluctuation) during a force modulation task, and twitch force were measured both before (pre-test) and after (post-test) the immobilization period. Data were analyzed by performing two-way (TIME×GROUP) repeated measures ANOVA. The MVC decreased in the immobilization group only (pre-test; 37.8±6.1N, post-test; 32.8±6.9N, p<0.0005) after the immobilization period. The force fluctuation increased only in the immobilization group (pre-test; 2.19±0.54%, post-test; 2.78±0.87%, p=0.007) after the immobilization period. These results demonstrate that induction of KiNVIS prevents negative effect on MVC and force fluctuation after 12h of immobilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Short-Term Upper Limb Immobilization Affects Action-Word Understanding

ERIC Educational Resources Information Center

Bidet-Ildei, Christel; Meugnot, Aurore; Beauprez, Sophie-Anne; Gimenes, Manuel; Toussaint, Lucette

2017-01-01

The present study aimed to investigate whether well-established associations between action and language can be altered by short-term upper limb immobilization. The dominant arm of right-handed participants was immobilized for 24 hours with a rigid splint fixed on the hand and an immobilization vest restraining the shoulder, arm, and forearm. The…

Enzyme Immobilization: An Overview on Methods, Support Material, and Applications of Immobilized Enzymes.

PubMed

Sirisha, V L; Jain, Ankita; Jain, Amita

Immobilized enzymes can be used in a wide range of processes. In recent years, a variety of new approaches have emerged for the immobilization of enzymes that have greater efficiency and wider usage. During the course of the last two decades, this area has rapidly expanded into a multidisciplinary field. This current study is a comprehensive review of a variety of literature produced on the different enzymes that have been immobilized on various supporting materials. These immobilized enzymes have a wide range of applications. These include applications in the sugar, fish, and wine industries, where they are used for removing organic compounds from waste water. This study also reviews their use in sophisticated biosensors for metabolite control and in situ measurements of environmental pollutants. Immobilized enzymes also find significant application in drug metabolism, biodiesel and antibiotic production, bioremediation, and the food industry. The widespread usage of immobilized enzymes is largely due to the fact that they are cheaper, environment friendly, and much easier to use when compared to equivalent technologies. © 2016 Elsevier Inc. All rights reserved.

Effect of sulfonylureas administered centrally on the blood glucose level in immobilization stress model.

PubMed

Sharma, Naveen; Sim, Yun-Beom; Park, Soo-Hyun; Lim, Su-Min; Kim, Sung-Su; Jung, Jun-Sub; Hong, Jae-Seung; Suh, Hong-Won

2015-05-01

Sulfonylureas are widely used as an antidiabetic drug. In the present study, the effects of sulfonylurea administered supraspinally on immobilization stress-induced blood glucose level were studied in ICR mice. Mice were once enforced into immobilization stress for 30 min and returned to the cage. The blood glucose level was measured 30, 60, and 120 min after immobilization stress initiation. We found that intracerebroventricular (i.c.v.) injection with 30 µg of glyburide, glipizide, glimepiride or tolazamide attenuated the increased blood glucose level induced by immobilization stress. Immobilization stress causes an elevation of the blood corticosterone and insulin levels. Sulfonylureas pretreated i.c.v. caused a further elevation of the blood corticosterone level when mice were forced into the stress. In addition, sulfonylureas pretreated i.c.v. alone caused an elevation of the plasma insulin level. Furthermore, immobilization stress-induced insulin level was reduced by i.c.v. pretreated sulfonylureas. Our results suggest that lowering effect of sulfonylureas administered supraspinally against immobilization stress-induced increase of the blood glucose level appears to be primarily mediated via elevation of the plasma insulin level.

Bostrycin, a novel coupling agent for protein immobilization and prevention of biomaterial-centered infection produced by Nigrospora sp. No. 407.

PubMed

Yang, Wen-Jen; Yang, Chih-Sheng; Huang, Chen-Ji; Chen, Ko-Shao; Lin, Shuen-Fuh

2012-05-10

Bostrycin, a red antibacterial agent with tetrahydroanthraquinone structure, has been isolated from Nigrospora sp. No. 407. This study investigated the potential antibacterial and multifunctional properties of matrixes through immobilization of bostrycin on their surface for immobilization of protein and prevention of bacterial growth. Bostrycin was immobilized on nonwoven polypropylene (PP) fabric by a technique using glutaraldehyde and polyethyleneimine for the activation of the surface. Glucose oxidase immobilized on bostrycin-treated nonwoven PP fabric showed high activity. The immobilization process improved thermal stability of the enzymes. During repeated assay for 30 cycles, the enzyme activity dropped to only 70% of the initial activity. Both bostrycin-treated nonwoven PP fabric sample and subsequently immobilized glucose oxidase sample on the surface also still exhibited a bacteriostatic effect. This is the first study to show that bostrycin is a promising coupling agent for surface modification on matrix and its potential applications in protein immobilization and biomaterial-centered infection. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

A preliminary study of continuous milk coagulation using Cynara cardunculus flower extract and calf rennet immobilized on magnetic particles.

PubMed

Liburdi, Katia; Emiliani Spinelli, Sara; Benucci, Ilaria; Lombardelli, Claudio; Esti, Marco

2018-01-15

The aim of this study was to develop a bioreactor design for continuous milk coagulation using a biocatalyst composed of immobilized animal and vegetable rennet on aminated magnetic particles, which has been proven to be an appropriate carrier for enzyme immobilization. Calf and vegetable (Cynara cardunculus) rennets were covalently immobilized on CLEA® magnetic supports and the immobilization procedure was optimized in batch mode, by evaluating protein loading, caseinolytic activity and the coagulation properties of skim milk powder and cow's milk. Subsequently the optimal temperature of immobilized coagulant was defined and a technically-friendly enzyme bioreactor was developed in order to carry out a continuous milk coagulation process with the aim of producing soft cheese. Copyright © 2017 Elsevier Ltd. All rights reserved.

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 study of the kinetics of biomaterials ossification

NASA Astrophysics Data System (ADS)

Weber, G.; Robaye, G.; Braye, F.; Oudadesse, H.; Irigaray, J. L.

1994-05-01

Biomaterials are frequently implanted in bones. This implantation is followed by a phenomenon of ossification. The purpose of this work was to study the time evolution of the gradient of characteristic atomic element's concentrations in the bone, the implant and the bone-implant interface. We have studied two types of neutral biomaterials: pure synthetic hydroxyapatite and porite's asteroid coral. The animal implantations have been made on sheep of the same age and sex having received the same basic diet. The implantations have been made in the cortical femur. On both sides of the implant, at the same distance, two screws were placed to allow further determination of the position of the implant. The PIXE method is particularly suitable here because of the possibility to analyze directly the samples without any preparation and to choose easily the dimensions of beam used for the gradient study. The X-rays have been detected with an ultra LEGe instead of the usual Si(Li) device to avoid the Si escape peak associated with the K α X-ray of calcium, the major constituent of bone. This peak is particularly disturbing here because its energy corresponds to the K α line of phosphorus, an important constituent of bone. The results of these determinations are presented and discussed.

Enhancement of Peroxidase Stability Against Oxidative Self-Inactivation by Co-immobilization with a Redox-Active Protein in Mesoporous Silicon and Silica Microparticles

NASA Astrophysics Data System (ADS)

Sahare, P.; Ayala, M.; Vazquez-Duhalt, R.; Pal, U.; Loni, A.; Canham, L. T.; Osorio, I.; Agarwal, V.

2016-09-01

The study of the stability enhancement of a peroxidase immobilized onto mesoporous silicon/silica microparticles is presented. Peroxidases tend to get inactivated in the presence of hydrogen peroxide, their essential co-substrate, following an auto-inactivation mechanism. In order to minimize this inactivation, a second protein was co-immobilized to act as an electron acceptor and thus increase the stability against self-oxidation of peroxidase. Two heme proteins were immobilized into the microparticles: a fungal commercial peroxidase and cytochrome c from equine heart. Two types of biocatalysts were prepared: one with only covalently immobilized peroxidase (one-protein system) and another based on covalent co-immobilization of peroxidase and cytochrome c (two-protein system), both immobilized by using carbodiimide chemistry. The amount of immobilized protein was estimated spectrophotometrically, and the characterization of the biocatalyst support matrix was performed using Brunauer-Emmett-Teller (BET), scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX), and Fourier transform infrared (FTIR) analyses. Stability studies show that co-immobilization with the two-protein system enhances the oxidative stability of peroxidase almost four times with respect to the one-protein system. Thermal stability analysis shows that the immobilization of peroxidase in derivatized porous silicon microparticles does not protect the protein from thermal denaturation, whereas biogenic silica microparticles confer significant thermal stabilization.

Kinetics of radiation-induced precipitation at the alloy surface

NASA Astrophysics Data System (ADS)

Lam, N. Q.; Nguyen, T.; Leaf, G. K.; Yip, S.

1988-05-01

Radiation-induced precipitation of a new phase at the surface of an alloy during irradiation at elevated temperatures was studied with the aid of a kinetic model of segregation. The preferential coupling of solute atoms with the defect fluxes gives rise to a strong solute enrichment at the surface, which, if surpassing the solute solubility limit, leads to the formation of a precipitate layer. The moving precipitate/matrix interface was accommodated by means of a mathematical scheme that transforms spatial coordinates into a reference frame in which the boundaries are immobile. Sample calculations were performed for precipitation of the γ'-Ni 3Si layer on Ni-Si alloys undergoing electron irradiation. The dependences of the precipitation kinetics on the defect-production rate, irradiation temperature, internal defect sink concentration and alloy composition were investigated systematically.

Follow-up of ankle stiffness and electromechanical delay in immobilized children: three cases studies.

PubMed

Grosset, Jean-François; Lapole, Thomas; Mora, Isabelle; Verhaeghe, Martine; Doutrellot, Pierre-Louis; Pérot, Chantal

2010-08-01

Clinical manual tests refer to increased ankle stiffness in children immobilized due to hip osteochondritis. The aim of the present study was to investigate musculo-articular stiffness via different techniques in immobilized children to confirm or not and quantify these observations. Ankle stiffness was quantified monthly during the long immobilization period in three diseased children and compared to healthy age-matched children. Sinusoidal perturbations were used to evaluate musculo-articular (MA) stiffness of the ankle plantar-flexors. The stiffness index (SI(MA-EMG)) was the slope of the linear relationship between angular stiffness and plantar-flexion torque normalized with electromyographic activity of the triceps surae (TS). The stiffness of the ankle plantar-flexors was also indirectly evaluated using the TS electromechanical delay (EMD). SI(MA-EMG) was greater for diseased children, and this higher stiffness was confirmed by the higher EMD values found in these immobilized children. Furthermore, both parameters indicated that ankle stiffness continues to increase through immobilization period. This study gives a quantitative evaluation of ankle stiffness changes through the immobilization period imposed to children treated for hip osteochondritis. The use of EMD measurement to indirectly evaluate these stiffness changes is also validated. This study shed for the first time some light into the patterns of muscle modifications following immobilization in children. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Rac1/RhoA antagonism defines cell-to-cell heterogeneity during epidermal morphogenesis in nematodes

PubMed Central

Ouellette, Marie-Hélène

2016-01-01

The antagonism between the GTPases Rac1 and RhoA controls cell-to-cell heterogeneity in isogenic populations of cells in vitro and epithelial morphogenesis in vivo. Its involvement in the regulation of cell-to-cell heterogeneity during epidermal morphogenesis has, however, never been addressed. We used a quantitative cell imaging approach to characterize epidermal morphogenesis at a single-cell level during early elongation of Caenorhabditis elegans embryos. This study reveals that a Rac1-like pathway, involving the Rac/Cdc42 guanine-exchange factor β-PIX/PIX-1 and effector PAK1/PAK-1, and a RhoA-like pathway, involving ROCK/LET-502, control the remodeling of apical junctions and the formation of basolateral protrusions in distinct subsets of hypodermal cells. In these contexts, protrusions adopt lamellipodia or an amoeboid morphology. We propose that lamella formation may reduce tension building at cell–cell junctions during morphogenesis. Cell-autonomous antagonism between these pathways enables cells to switch between Rac1- and RhoA-like morphogenetic programs. This study identifies the first case of cell-to-cell heterogeneity controlled by Rac1/RhoA antagonism during epidermal morphogenesis. PMID:27821782

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.

ESO and NSF Sign Agreement on ALMA

NASA Astrophysics Data System (ADS)

2003-02-01

Green Light for World's Most Powerful Radio Observatory On February 25, 2003, the European Southern Observatory (ESO) and the US National Science Foundation (NSF) are signing a historic agreement to construct and operate the world's largest and most powerful radio telescope, operating at millimeter and sub-millimeter wavelength. The Director General of ESO, Dr. Catherine Cesarsky, and the Director of the NSF, Dr. Rita Colwell, act for their respective organizations. Known as the Atacama Large Millimeter Array (ALMA), the future facility will encompass sixty-four interconnected 12-meter antennae at a unique, high-altitude site at Chajnantor in the Atacama region of northern Chile. ALMA is a joint project between Europe and North America. In Europe, ESO is leading on behalf of its ten member countries and Spain. In North America, the NSF also acts for the National Research Council of Canada and executes the project through the National Radio Astronomy Observatory (NRAO) operated by Associated Universities, Inc. (AUI). The conclusion of the ESO-NSF Agreement now gives the final green light for the ALMA project. The total cost of approximately 650 million Euro (or US Dollars) is shared equally between the two partners. Dr. Cesarsky is excited: "This agreement signifies the start of a great project of contemporary astronomy and astrophysics. Representing Europe, and in collaboration with many laboratories and institutes on this continent, we together look forward towards wonderful research projects. With ALMA we may learn how the earliest galaxies in the Universe really looked like, to mention but one of the many eagerly awaited opportunities with this marvellous facility". "With this agreement, we usher in a new age of research in astronomy" says Dr. Colwell. "By working together in this truly global partnership, the international astronomy community will be able to ensure the research capabilities needed to meet the long-term demands of our scientific enterprise, and that we will be able to study and understand our universe in ways that have previously been beyond our vision". The recent Presidential decree from Chile for AUI and the agreement signed in late 2002 between ESO and the Government of the Republic of Chile (cf. ESO PR 18/02) recognize the interest that the ALMA Project has for Chile, as it will deepen and strengthen the cooperation in scientific and technological matters between the parties. A joint ALMA Board has been established which oversees the realisation of the ALMA project via the management structure. This Board meets for the first time on February 24-25, 2003, at NSF in Washington and will witness this historic event. ALMA: Imaging the Light from Cosmic Dawn ESO PR Photo 06a/03 ESO PR Photo 06a/03 [Preview - JPEG: 588 x 400 pix - 52k [Normal - JPEG: 1176 x 800 pix - 192k] [Hi-Res - JPEG: 3300 x 2244 pix - 2.0M] ESO PR Photo 06b/03 ESO PR Photo 06b/03 [Preview - JPEG: 502 x 400 pix - 82k [Normal - JPEG: 1003 x 800 pix - 392k] [Hi-Res - JPEG: 2222 x 1773 pix - 3.0M] ESO PR Photo 06c/03 ESO PR Photo 06c/03 [Preview - JPEG: 474 x 400 pix - 84k [Normal - JPEG: 947 x 800 pix - 344k] [Hi-Res - JPEG: 2272 x 1920 pix - 2.0M] ESO PR Photo 06d/03 ESO PR Photo 06d/03 [Preview - JPEG: 414 x 400 pix - 69k [Normal - JPEG: 828 x 800 pix - 336k] [HiRes - JPEG: 2935 x 2835 pix - 7.4k] Captions: PR Photo 06a/03 shows an artist's view of the Atacama Large Millimeter Array (ALMA), with 64 12-m antennae. PR Photo 06b/03 is another such view, with the array arranged in a compact configuration at the high-altitude Chajnantor site. The ALMA VertexRSI prototype antennae is shown in PR Photo 06c/03 on the Antenna Test Facility (ATF) site at the NRAO Very Large Array (VLA) site near Socorro (New Mexico, USA). The future ALMA site at Llano de Chajnantor at 5000 metre altitude, some 40 km East of the village of San Pedro de Atacama (Chile) is seen in PR Photo 06d/03 - this view was obtained at 11 hrs in the morning on a crisp and clear autumn day (more views of this site are available at the Chajnantor Photo Gallery). The Atacama Large Millimeter Array (ALMA) will be one of astronomy's most powerful telescopes - providing unprecedented imaging capabilities and sensitivity in the corresponding wavelength range, many orders of magnitude greater than anything of its kind today. ALMA will be an array of 64 antennae that will work together as one telescope to study millimeter and sub-millimeter wavelength radiation from space. This radiation crosses the critical boundary between infrared and microwave radiation and holds the key to understanding such processes as planet and star formation, the formation of early galaxies and galaxy clusters, and the formation of organic and other molecules in space. "ALMA will be one of astronomy's premier tools for studying the universe" says Nobel Laureate Riccardo Giacconi, President of AUI (and former ESO Director General (1993-1999)). "The entire astronomical community is anxious to have the unprecedented power and resolution that ALMA will provide". The President of the ESO Council, Professor Piet van der Kruit, agrees: "ALMA heralds a break-through in sub-millimeter and millimeter astronomy, allowing some of the most penetrating studies the Universe ever made. It is safe to predict that there will be exciting scientific surprises when ALMA enters into operation". What is millimeter and sub-millimeter wavelength astronomy? Astronomers learn about objects in space by studying the energy emitted by those objects. Our Sun and the other stars throughout the Universe emit visible light. But these objects also emit other kinds of light waves, such as X-rays, infrared radiation, and radio waves. Some objects emit very little or no visible light, yet are strong sources at other wavelengths in the electromagnetic spectrum. Much of the energy in the Universe is present in the sub-millimeter and millimeter portion of the spectrum. This energy comes from the cold dust mixed with gas in interstellar space. It also comes from distant galaxies that formed many billions of years ago at the edges of the known universe. With ALMA, astronomers will have a uniquely powerful facility with access to this remarkable portion of the spectrum and hence, new and wonderful opportunities to learn more about those objects. Current observatories simply do not have anywhere near the necessary sensitivity and resolution to unlock the secrets that abundant sub-millimeter and millimeter wavelength radiation can reveal. It will take the unparalleled power of ALMA to fully study the cosmic emission at this wavelength and better understand the nature of the universe. Scientists from all over the world will use ALMA. They will compete for observing time by submitting proposals, which will be judged by a group of their peers on the basis of scientific merit. ALMA's unique capabilities ALMA's ability to detect remarkably faint sub-millimeter and millimeter wavelength emission and to create high-resolution images of the source of that emission gives it capabilities not found in any other astronomical instruments. ALMA will therefore be able to study phenomena previously out of reach to astronomers and astrophysicists, such as: * Very young galaxies forming stars at the earliest times in cosmic history; * New planets forming around young stars in our galaxy, the Milky Way; * The birth of new stars in spinning clouds of gas and dust; and * Interstellar clouds of gas and dust that are the nurseries of complex molecules and even organic chemicals that form the building blocks of life. How will ALMA work? All of ALMA's 64 antennae will work in concert, taking quick "snapshots" or long-term exposures of astronomical objects. Cosmic radiation from these objects will be reflected from the surface of each antenna and focussed onto highly sensitive receivers cooled to just a few degrees above absolute zero in order to suppress undesired "noise" from the surroundings. There the signals will be amplified many times, digitized, and then sent along underground fiber-optic cables to a large signal processor in the central control building. This specialized computer, called a correlator - running at 16,000 million-million operations per second - will combine all of the data from the 64 antennae to make images of remarkable quality. The extraordinary ALMA site Since atmospheric water vapor absorbs millimeter and (especially) sub-millimeter waves, ALMA must be constructed at a very high altitude in a very dry region of the earth. Extensive tests showed that the sky above the Atacama Desert of Chile has the excellent clarity and stability essential for ALMA. That is why ALMA will be built there, on Llano de Chajnantor at an altitude of 5,000 metres in the Chilean Andes. A series of views of this site, also in high-resolution suitable for reproduction, is available at the Chajnantor Photo Gallery. Timeline for ALMA June 1998: Phase 1 (Research and Development) June 1999: European/American Memorandum of Understanding February 2003: Signature of the bilateral Agreement 2004: Tests of the Prototype System 2007: Initial scientific operation of a partially completed array 2011: End of construction of the array

Histomorphometric analysis of the response of rat skeletal muscle to swimming, immobilization and rehabilitation.

PubMed

Nascimento, C C F; Padula, N; Milani, J G P O; Shimano, A C; Martinez, E Z; Mattiello-Sverzut, A C

2008-09-01

The objective of the present study was to determine to what extent, if any, swimming training applied before immobilization in a cast interferes with the rehabilitation process in rat muscles. Female Wistar rats, mean weight 260.52 +/- 16.26 g, were divided into 4 groups of 6 rats each: control, 6 weeks under baseline conditions; trained, swimming training for 6 weeks; trained-immobilized, swimming training for 6 weeks and then immobilized for 1 week; trained-immobilized-rehabilitated, swimming training for 6 weeks, immobilized for 1 week and then remobilized with swimming for 2 weeks. The animals were then sacrificed and the soleus and tibialis anterior muscles were dissected, frozen in liquid nitrogen and processed histochemically (H&E and mATPase). Data were analyzed statistically by the mixed effects linear model (P < 0.05). Cytoarchitectural changes such as degenerative characteristics in the immobilized group and regenerative characteristics such as centralized nucleus, fiber size variation and cell fragmentation in the groups submitted to swimming were more significant in the soleus muscle. The diameters of the lesser soleus type 1 and type 2A fibers were significantly reduced in the trained-immobilized group compared to the trained group (P < 0.001). In the tibialis anterior, there was an increase in the number of type 2B fibers and a reduction in type 2A fibers when trained-immobilized rats were compared to trained rats (P < 0.001). In trained-immobilized-rehabilitated rats, there was a reduction in type 2B fibers and an increase in type 2A fibers compared to trained-immobilized rats (P < 0.009). We concluded that swimming training did not minimize the deleterious effects of immobilization on the muscles studied and that remobilization did not favor tissue re-adaptation.

Sustainable biodegradation of phenol by immobilized Bacillus sp. SAS19 with porous carbonaceous gels as carriers.

PubMed

Ke, Qian; Zhang, Yunge; Wu, Xilin; Su, Xiaomei; Wang, Yuyang; Lin, Hongjun; Mei, Rongwu; Zhang, Yu; Hashmi, Muhammad Zaffar; Chen, Chongjun; Chen, Jianrong

2018-09-15

In this study, high-efficient phenol-degrading bacterium Bacillus sp. SAS19 which was isolated from activated sludge by resuscitation-promoting factor (Rpf) addition, were immobilized on porous carbonaceous gels (CGs) for phenol degradation. The phenol-degrading capabilities of free and immobilized Bacillus sp. SAS19 were evaluated under various initial phenol concentrations. The obtained results showed that phenol could be removed effectively by both free and immobilized Bacillus sp. SAS19. Furthermore, for degradation of phenol at high concentrations, long-term utilization and recycling were more readily achieved for immobilized bacteria as compared to free bacteria. Immobilized bacteria exhibited significant increase in phenol-degrading capabilities in the third cycle of recycling and reuse, which demonstrated 87.2% and 100% of phenol (1600 mg/L) degradation efficiency at 12 and 24 h, respectively. The present study revealed that immobilized Bacillus sp. SAS19 can be potentially used for enhanced treatment of synthetic phenol-laden wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

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.

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.

Preparation, characterization and catalytic behavior of pectinase covalently immobilized onto sodium alginate/graphene oxide composite beads.

PubMed

Dai, Xiao-Yan; Kong, Li-Min; Wang, Xiao-Ling; Zhu, Qing; Chen, Kai; Zhou, Tao

2018-07-01

Pectinase was immobilized onto sodium alginate/graphene oxide beads via amide bonds by using N,N'-dicyclohexylcarbodiimide/N-hydroxysuccinimide as the activating agent. The immobilized pectinase was characterized by Fourier transform infrared spectra and scanning electron microscopy analyses. Immobilization conditions were optimized by Box-Behnken design and the response surface method. The activity of the immobilized pectinase prepared under optimal conditions reached 1236.86 ± 40.21 U/g, with an enzyme activity recovery of 83.5%. The optimal pH of free pectinase was 4.5, while that of immobilized pectinase was shifted to 4.0. The optimal temperature of immobilized pectinase was increased to 60 °C, which was 10 °C higher than that of free form. Furthermore, the immobilized pectinase possessed a superior thermal stability and storage stability to those of free pectinase. Reusability studies indicated that the immobilized pectinase retained 73% of initial activity after six times cycles. Due to these good properties, such immobilized pectinase may find application in food industry. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhancement stability and catalytic activity of immobilized α-amylase using bioactive phospho-silicate glass as a novel inorganic support.

PubMed

Ahmed, Samia A; Mostafa, Faten A; Ouis, Mona A

2018-06-01

α-Amylase enzyme was immobilized on bioactive phospho-silicate glass (PS-glass) as a novel inorganic support by physical adsorption and covalent binding methods using glutaraldehyde and poly glutaraldehyde as a spacer. Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) studies confirmed the glass-enzyme linkage. Dissolution of PS-glass in acidic and neutral pH is higher than that of alkaline pH. Some immobilization variables were optimized using statistical factorial design (Central Composite Design). Optimized immobilization variables enhanced the immobilization yield (IY) from 27.9 to 79.9% (2.9-fold). It was found that the immobilized enzyme had higher optimum temperature, higher half-life time (t 1/2 ), lower activation energy (E a ), lower deactivation constant rate (k d ) and higher decimal reduction time (D-values) within the temperature range of 40-60°C. Differential scanning calorimetry analysis (DSC) confirmed the thermalstability of the immobilized enzyme. The immobilized enzyme was stable at a wide pH range (5.0-8.0). Kinetic studies of starch hydrolysis demonstrated that immobilized enzyme had lower Michaelis constant (K m ), maximum velocity (V max ) and catalytic efficiency (V max /K m ) values. The storage stability and reusability of the immobilized enzyme were found to be about 74.7 and 62.5% of its initial activity after 28days and 11cycles, respectively. Enhanced α-amylase stabilities upon immobilization make it suitable for industrial application. Copyright © 2018 Elsevier B.V. All rights reserved.

Covalent immobilization of invertase on PAMAM-dendrimer modified superparamagnetic iron oxide nanoparticles

NASA Astrophysics Data System (ADS)

Uzun, K.; Çevik, E.; Şenel, M.; Sözeri, H.; Baykal, A.; Abasıyanık, M. F.; Toprak, M. S.

2010-10-01

In this study, polyamidoamine (PAMAM) dendrimer was synthesized on the surface of superparamagnetite nanoparticles to enhance invertase immobilization. The amount of immobilized enzyme on the surface-hyperbranched magnetite nanoparticle was up to 2.5 times (i.e., 250%) as much as that of magnetite nanoparticle modified with only amino silane. Maximum reaction rate ( V max) and Michaelis-Menten constant ( K m) were determined for the free and immobilized enzymes. Various characteristics of immobilized invertase such as; the temperature activity, thermal stability, operational stability, and storage stability were evaluated and results revealed that stability of the enzyme is improved upon immobilization.

Immobilization of Aspergillus niger xylanase on magnetic latex beads.

PubMed

Tyagi, R; Gupta, M N

1995-04-01

Xylanase from Pectinex 3XL was purified 70-fold by precipitation with an enteric polymer, Eudragit S-100. The purified xylanase was immobilized on magnetic latex beads via carbodi-imide coupling. The immobilized preparation showed 80% of the total activity bound to the beads. The pH optimum remained unchanged at 6.0 and the Km increased from 0.25 g/100 ml (free enzyme) to 0.39 g/100 ml on immobilization. Immobilization resulted in significant thermal stability at 60 degrees C. The time course of hydrolysis of xylan at 60 degrees C by free enzyme as well as immobilized enzyme was also studied.

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.

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.

Biotechnological potential of Azolla filiculoides for biosorption of Cs and Sr: Application of micro-PIXE for measurement of biosorption.

PubMed

Ghorbanzadeh Mashkani, Saeid; Tajer Mohammad Ghazvini, Parisa

2009-03-01

The presence of Cs and Sr in culture medium of Azolla filiculoides caused about 27.4% and 46.3% inhibition of biomass growth, respectively, in comparison to A. filiculoides control weight which had not metals. Biosorption batch experiments were conducted to determine the Cs and Sr binding ability of native biomass and chemically modified biosorbents derived from Azolla namely ferrocyanide Azolla sorbents type 1 and type 2 (FAS1 and FAS2) and hydrogen peroxide Azolla sorbent (HAS). The best Cs and Sr removal results were obtained when A. filiculoides was treated by 2M MgCl(2) and 30ml H(2)O(2) 8mM at pH 7 for 12h and it was then washed by NaOH solution at pH 10.5 for 6h. Pretreatment of Azolla have been suggested to modify the surface characteristics which could improve biosorption process. The binding of Cs and Sr on the cell wall of Azolla was studied with micro-PIXE and FT-IR.

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.

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

Solvent Stability Study with Thermodynamic Analysis and Superior Biocatalytic Activity of Burkholderia cepacia Lipase Immobilized on Biocompatible Hybrid Matrix of Poly(vinyl alcohol) and Hypromellose.

PubMed

Badgujar, Kirtikumar C; Bhanage, Bhalchandra M

2014-12-26

In the present study, we have synthesized a biocompatible hybrid carrier of hypromellose (HY) and poly(vinyl alcohol) (PVA) for immobilization of Burkholderia cepacia lipase (BCL). The immobilized biocatalyst HY:PVA:BCL was subjected to determination of half-life time (τ) and deactivation rate constant (K(D)) in various organic solvents. Biocatalyst showed higher τ-value in a nonpolar solvent like cyclohexane (822 h) as compared to that of a polar solvent such as acetone (347 h), which signifies better compatibility of biocatalyst in the nonpolar solvents. Furthermore, the K(D)-value was found to be less in cyclohexane (0.843 × 10(-3)) as compared to acetone (1.997 × 10(-3)), indicating better stability in the nonpolar solvents. Immobilized-BCL (35 mg) was sufficient to achieve 99% conversion of phenethyl butyrate (natural constituent of essential oils and has wide industrial applications) using phenethyl alcohol (2 mmol) and vinyl butyrate (6 mmol) at 44 °C in 3 h. The activation energy (E(a)) was found to be lower for immobilized-BCL than crude-BCL, indicating better catalytic efficiency of immobilized lipase BCL. The immobilized-BCL reported 6-fold superior biocatalytic activity and 8 times recyclability as compared to crude-BCL. Improved catalytic activity of immobilized enzyme in nonpolar media was also supported by thermodynamic activation parameters such as enthalpy (ΔH(⧧)), entropy (ΔS(⧧)) and Gibb's free energy (ΔG(⧧)) study, which showed that phenethyl butyrate synthesis catalyzed by immobilized-BCL was feasible as compared to crude-BCL. The present work explains a thermodynamic investigation and superior biocatalytic activity for phenethyl butyrate synthesis using biocompatible immobilized HY:PVA:BCL in nonaqueous media for the first time.

Aided Phytostabilization of Copper Contaminated Soils with L. Perenne and Mineral Sorbents as Soil Amendments

NASA Astrophysics Data System (ADS)

Radziemska, Maja

2017-09-01

The present study was designed to assess phytostabilization strategies for the treatment of soil co-contaminated by increasing levels of copper with the application mineral amendments (chalcedonite, zeolite, dolomite). From the results it will be possible to further elucidate the benefits or potential risks derived from the application of different types of mineral amendments in the remediation of a copper contaminated soil. A glasshouse pot experiment was designed to evaluate the potential use of different amendments as immobilizing agents in the aided phytostabilization of Cu-contaminated soil using ryegrass (Lolium perenne L.). The content of trace elements in plants and total in soil, were determined using the method of spectrophotometry. All of the investigated element contents in the tested parts of L. perenne were significantly different in the case of applying mineral amendments to the soil, as well as increasing concentrations of copper. The greatest average above-ground biomass was observed for soil amended with chalcedonite. In this experiment, all analyzed metals accumulated predominantly in the roots of the tested plant. In general, applying mineral amendments to soil contributed to decreased levels of copper concentrations.

Optimization of Enzyme Co-Immobilization with Sodium Alginate and Glutaraldehyde-Activated Chitosan Beads.

PubMed

Gür, Sinem Diken; İdil, Neslihan; Aksöz, Nilüfer

2018-02-01

In this study, two different materials-alginate and glutaraldehyde-activated chitosan beads-were used for the co-immobilization of α-amylase, protease, and pectinase. Firstly, optimization of multienzyme immobilization with Na alginate beads was carried out. Optimum Na alginate and CaCl 2 concentration were found to be 2.5% and 0.1 M, respectively, and optimal enzyme loading ratio was determined as 2:1:0.02 for pectinase, protease, and α-amylase, respectively. Next, the immobilization of multiple enzymes on glutaraldehyde-activated chitosan beads was optimized (3% chitosan concentration, 0.25% glutaraldehyde with 3 h of activation and 3 h of coupling time). While co-immobilization was successfully performed with both materials, the specific activities of enzymes were found to be higher for the enzymes co-immobilized with glutaraldehyde-activated chitosan beads. In this process, glutaraldehyde was acting as a spacer arm. SEM and FTIR were used for the characterization of activated chitosan beads. Moreover, pectinase and α-amylase enzymes immobilized with chitosan beads were also found to have higher activity than their free forms. Three different enzymes were co-immobilized with these two materials for the first time in this study.

Advances in ethanol production using immobilized cell systems

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

Margaritis, A.; Merchant, F.J.A.

The application of immobilized cell systems for the production of ethanol has resulted in substantial improvements in the efficiency of the process when compared to the traditional free cell system. In this review, the various methods of cell immobilization employed in ethanol production systems have been described in detail. Their salient features, performance characteristics, advantages and limitations have been critically assessed. More recently, these immobilized cell systems have also been employed for the production of ethanol from non-conventional feedstocks such as Jerusalem artichoke extracts, cheese whey, cellulose, cellobiose and xylose. Ethanol production by immobilized yeast and bacterial cells has beenmore » attempted in various bioreactor types. Although most of these studies have been carried out using laboratory scale prototype bioreactors, it appears that only fluidized bed, horizontally packed bed bioreactors and tower fermenters may find application on scale-up. Several studies have indicated that upon immobilization, yeast cells performing ethanol fermentation exhibit more favourable physiological and metabolic properties. This, in addition to substantial improvements in ethanol productivities by immobilized cell systems, is indicative of the fact that future developments in the production of ethanol and alcoholic beverages will be directed towards the use of immobilized cell systems. 291 references.« less

Preliminary studies on immobilization of lipase using chicken eggshell

NASA Astrophysics Data System (ADS)

Salleh, S.; Serri, N. A.; Hena, S.; Tajarudin, H. A.

2016-06-01

A few advantages of enzyme immobilization are reusability of expensive enzyme, improvement of stability and activity compared to crude enzyme. Various organic components can be used as carrier for enzyme immobilization such as chicken eggshell. It can be used as a carrier for immobilization as its mineral component mostly contains of calcium carbonate. In the present study, Tributyrin method was used to test enzyme activity of Rhizomucour Miehei, Candida Antarctica and Candida Rugosa. Rhizomucour Miehei shows the highest enzyme activity (360.8 mol/min/mL lipase) and was used in further experiment. Experiment was continued to study incubation time for lipase immobilization on eggshell (1-4 hours) and reaction time of esterification of sugar ester (0-72 hours). Two hours incubation time for lipase immobilization was observed and gives the highest yield of sugar ester (78.13%). Fructose and stearic acid as substrate was used for the production of sugar ester. The highest percentage of sugar ester production was shown at 36 hours of reaction time.

Covalent attachment of microbial lipase onto microporous styrene-divinylbenzene copolymer by means of polyglutaraldehyde.

PubMed

Dizge, Nadir; Keskinler, Bülent; Tanriseven, Aziz

2008-10-01

A novel method for immobilization of Thermomyces lanuginosus lipase onto polyglutaraldehyde-activated poly(styrene-divinylbenzene) (STY-DVB), which is a hydrophobic microporous support has been successfully developed. The copolymer was prepared by the polymerization of the continuous phase of a high internal phase emulsion (polyHIPE). The concentrated emulsion consists of a mixture of styrene and divinylbenzene containing a suitable surfactant and an initiator as the continuous phase and water as the dispersed phase. Lipase from T. lanuginosus was immobilized covalently with 85% yield on the internal surface of the hydrophobic microporous poly(styrene-divinylbenzene) copolymer and used as a biocatalyst for the transesterification reaction. The immobilized enzyme has been fully active 30 days in storage and retained the activity during the 15 repeated batch reactions. The properties of free and immobilized lipase were studied. The effects of protein concentration, pH, temperature, and time on the immobilization, activity, and stability of the immobilized lipase were also studied. The newly synthesized microporous poly(styrene-divinylbenzene) copolymer constitutes excellent support for lipase. It given rise to high immobilization yield, retains enzymatic activity for 30 days, stable in structure and allows for the immobilization of large amount of protein (11.4mg/g support). Since immobilization is simple yet effective, the newly immobilized lipase could be used in several application including oil hydrolysis, production of modified oils, biodiesel synthesis, and removal of fatty acids from oils.

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.

Investigation of soils affected by burnt hospital wastes in Nigeria using PIXE.

PubMed

Ephraim P, Inyang; Ita, Akpan; Eusebius I, Obiajunwa

2013-12-01

Improper management of hospital waste has been reported to be responsible for several acute outbreaks like the severe acute respiratory syndrome (SARS). In spite of these challenges, hospital wastes are sometimes not properly handled in Nigeria. To date, there has not been an adequate study on the effect and fate of burnt hospital waste on agricultural soil. The effect of burnt hospital wastes on the agricultural soil was conducted on soils sampled around farm settlement near Obafemi Awolowo University Teaching Hospital Complex, Ile-Ife, South West Nigeria. PIXE technique was employed with a 1.7 MV 5SDH Tandem Pelletron accelerator available at Centre for Energy Research and Development O.A.U Ile-Ife, Nigeria. Eleven elements- Si, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Zr and Pb were detected and their concentrations and enrichment factors determined. The presence of Pb and Cl at the elevated concentrations range of (77.8 ± 3.5 - 279.6 ± 97.6 and 102.2 ± 37.4 -167.2±17.43) ppm respectively in this study, is of serious health concern because of the agricultural practices in the neighborhoods of the study sites. There is a need for proper handling of hospital and other related hazardous wastes because of the possibility of such posing serious environmental pollution problems.

Chemical stabilization of metals and arsenic in contaminated soils using oxides--a review.

PubMed

Komárek, Michael; Vaněk, Aleš; Ettler, Vojtěch

2013-01-01

Oxides and their precursors have been extensively studied, either singly or in combination with other amendments promoting sorption, for in situ stabilization of metals and As in contaminated soils. This remediation option aims at reducing the available fraction of metal(loid)s, notably in the root zone, and thus lowering the risks associated with their leaching, ecotoxicity, plant uptake and human exposure. This review summarizes literature data on mechanisms involved in the immobilization process and presents results from laboratory and field experiments, including the subsequent influence on higher plants and aided phytostabilization. Despite the partial successes in the field, recent knowledge highlights the importance of long-term and large-scale field studies evaluating the stability of the oxide-based amendments in the treated soils and their efficiency in the long-term. Copyright © 2012 Elsevier Ltd. All rights reserved.

Carbodiimide for Covalent α-Amylase Immobilization onto Magnetic Nanoparticles

NASA Astrophysics Data System (ADS)

Milani, Zeinab Mortazavi; Jalal, Razieh; Goharshadi, Elaheh K.

Covalent cross-linking of enzymes to magnetite (Fe3O4) nanoparticles (MNPs) is one of the useful enzyme immobilization methods which provides repeated use of the catalyst, facilitates enzyme separation from the reaction mixture, and sometimes improves biocatalysts stability. The aim of this study was to immobilize α-amylase onto MNPs via covalent attachment using carbodiimide (CDI) molecules. MNPs were synthesized by the co-precipitation method. The size and the structure of the particles were characterized by X-ray diffraction and transmission electron microscopy. The effects of different operational conditions of direct α-amylase binding on MNPs in the presence of CDI were investigated by using the shaking method. Fourier transform infrared spectroscopy was used to confirm the success of immobilization. The optimum conditions and catalytic properties of immobilized α-amylase were also evaluated. The efficiency of immobilization and the residual activity of the immobilized α-amylase were dependent on the mass ratio of MNPs: CDI: α-amylase and the immobilization temperature. The optimum pH for the free and immobilized amylase was 6. The free and immobilized α-amylase showed maximum activity at 20∘C and 35∘C, respectively. The immobilized α-amylase was more thermostable than the free one. The retained activity for free α-amylase after 19 storage days was 57.7% whereas it was 100% for the immobilized α-amylase. In repeated batch experiments, the immobilized α-amylase retained a residual activity of 45% after 11 repeated uses. The Km and Vmax values for the immobilized enzyme were larger than those of the free enzyme. The immobilization of α-amylase on MNPs using CDI improves its stability and reusability.

Removal of acetaminophen in water by laccase immobilized in barium alginate.

PubMed

Ratanapongleka, Karnika; Punbut, Supot

2018-02-01

This research has focused on the optimization of immobilized laccase condition and utilization in degradation of acetaminophen contaminated in aqueous solution. Laccase from Lentinus polychrous was immobilized in barium alginate. The effects of laccase immobilization such as sodium alginate concentration, barium chloride concentration and gelation time were studied. The optimal conditions for immobilization were sodium alginate 5% (w/v), barium chloride 5% (w/v) and gelation time of 60 min. Immobilized laccase was then used for acetaminophen removal. Acetaminophen was removed quickly in the first 50 min. The degradation rate and percentage of removal increased when the enzyme concentration increased. Immobilized laccase at 0.57 U/g-alginate showed the maximum removal at 94% in 240 min. The removal efficiency decreased with increasing initial acetaminophen concentration. The K m value for immobilized laccase (98.86 µM) was lower than that of free laccase (203.56 µM), indicating that substrate affinity was probably enhanced by immobilization. The immobilized enzyme exhibited high activity and good acetaminophen removal at pH 7 and temperature of 35°C. The activation energies of free and immobilized laccase for degradation of acetaminophen were 8.08 and 17.70 kJ/mol, respectively. It was also found that laccase stability to pH and temperature increased after immobilization. Furthermore, immobilized laccase could be reused for five cycles. The capability of removal and enzyme activity were retained above 70%.

Protein immobilization techniques for microfluidic assays

PubMed Central

Kim, Dohyun; Herr, Amy E.

2013-01-01

Microfluidic systems have shown unequivocal performance improvements over conventional bench-top assays across a range of performance metrics. For example, specific advances have been made in reagent consumption, throughput, integration of multiple assay steps, assay automation, and multiplexing capability. For heterogeneous systems, controlled immobilization of reactants is essential for reliable, sensitive detection of analytes. In most cases, protein immobilization densities are maximized, while native activity and conformation are maintained. Immobilization methods and chemistries vary significantly depending on immobilization surface, protein properties, and specific assay goals. In this review, we present trade-offs considerations for common immobilization surface materials. We overview immobilization methods and chemistries, and discuss studies exemplar of key approaches—here with a specific emphasis on immunoassays and enzymatic reactors. Recent “smart immobilization” methods including the use of light, electrochemical, thermal, and chemical stimuli to attach and detach proteins on demand with precise spatial control are highlighted. Spatially encoded protein immobilization using DNA hybridization for multiplexed assays and reversible protein immobilization surfaces for repeatable assay are introduced as immobilization methods. We also describe multifunctional surface coatings that can perform tasks that were, until recently, relegated to multiple functional coatings. We consider the microfluidics literature from 1997 to present and close with a perspective on future approaches to protein immobilization. PMID:24003344

Solid-support immobilization of a "swing" fusion protein for enhanced glucose oxidase catalytic activity.

PubMed

Takatsuji, Yoshiyuki; Yamasaki, Ryota; Iwanaga, Atsushi; Lienemann, Michael; Linder, Markus B; Haruyama, Tetsuya

2013-12-01

The strategic surface immobilization of a protein can add new functionality to a solid substrate; however, protein activity, e.g., enzymatic activity, can be drastically decreased on immobilization onto a solid surface. The concept of a designed and optimized "molecular interface" is herein introduced in order to address this problem. In this study, molecular interface was designed and constructed with the aim of attaining high enzymatic activity of a solid-surface-immobilized a using the hydrophobin HFBI protein in conjunction with a fusion protein of HFBI attached to glucose oxidase (GOx). The ability of HFBI to form a self-organized membrane on a solid surface in addition to its adhesion properties makes it an ideal candidate for immobilization. The developed fusion protein was also able to form an organized membrane, and its structure and immobilized state on a solid surface were investigated using QCM-D measurements. This method of immobilization showed retention of high enzymatic activity and the ability to control the density of the immobilized enzyme. In this study, we demonstrated the importance of the design and construction of molecular interface for numerous purposes. This method of protein immobilization could be utilized for preparation of high throughput products requiring structurally ordered molecular interfaces, in addition to many other applications. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Immobilization of α-amylase onto a calix[4]arene derivative: Evaluation of its enzymatic activity.

PubMed

Veesar, Irshad Ali; Solangi, Imam Bakhsh; Memon, Shahabuddin

2015-06-01

In order to enhance the cost-effectiveness practicability of enzymes in many industries such as pharmaceutical, food, medical and some other technological processes, there is great need to immobilize them onto a solid supports. In this study, a new and efficient immobilization of α-amylase from Saccharomyces cerevisiae has been developed by using the surface functionalization of calix[4]arene as support. A glutaraldehyde-containing amino group functionalized calix[4]arene was used to immobilize α-amylase covalently. In this procedure, imide bonds are formed between amino groups on the protein and aldehyde groups on the calix[4]arene surface. The surface modified support was characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM). The effect of various preparation conditions on the immobilized α-amylase process such as immobilization time, enzyme concentration, temperature and pH were investigated. The influence of pH and temperature on the activity of free and immobilized α-amylase was also studied using starch as substrate. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized α-amylase were 25°C and 7, respectively. Compared to the free enzyme, the immobilized α-amylase retained 85% of its original activity and exhibited significant thermal stability than the free one and excellent durability. Copyright © 2015 Elsevier Inc. All rights reserved.

The LHCb VELO upgrade

NASA Astrophysics Data System (ADS)

Dosil Suárez, Álvaro; LHCb VELO Upgrade Group

2016-07-01

The upgrade of the LHCb experiment, planned for 2019, will transform the experiment to a trigger-less system reading out the full detector at 40 MHz event rate. All data reduction algorithms will be executed in a high-level software farm. The upgraded detector will run at luminosities of 2×1033 cm-2 s-1 and probe physics beyond the Standard Model in the heavy flavour sector with unprecedented precision. The Vertex Locator (VELO) is the silicon vertex detector surrounding the interaction region. The current detector will be replaced with a hybrid pixel system equipped with electronics capable of reading out at 40 MHz. The detector comprises silicon pixel sensors with 55×55 μm2 pitch, read out by the VeloPix ASIC, based on the TimePix/MediPix family. The hottest region will have pixel hit rates of 900 Mhits/s yielding a total data rate more than 3 Tbit/s for the upgraded VELO. The detector modules are located in a separate vacuum, separated from the beam vacuum by a thin custom made foil. The detector halves are retracted when the beams are injected and closed at stable beams, positioning the first sensitive pixel at 5.1 mm from the beams. The material budget will be minimised by the use of evaporative CO2 coolant circulating in microchannels within 400 μm thick silicon substrates.

Is prolonged immobilization a risk factor for symptomatic venous thromboembolism in elderly bedridden patients? Results of a historical-cohort study.

PubMed

Gatt, Moshe E; Paltiel, Ora; Bursztyn, Michael

2004-03-01

Prolonged immobilization and advanced age are considered to be important risk factors for venous thromboembolism (VTE). Nevertheless, the need for VTE prophylaxis in long-term bedridden patients is not known. To assess whether very prolonged immobilization (i.e. over three months) carries an increased risk for clinically apparent VTE, we performed a historical-cohort study of nursing home residents during a ten-year period. Data concerning patient's mobility and incidence of overt deep vein thrombosis or pulmonary embolism were registered. The mean resident age was 85+/-8.4 years. Eighteen mobile and eight immobile patients were diagnosed with clinically significant thromboembolic events, during 1137 and 573 patient-years of follow up, respectively. The incidence of venous thromboembolic events was similar in both chronically immobilized and mobile patient groups, 13.9 and 15.8 per thousand patient years, respectively (p=0.77). The rate ratio for having a VTE event in the immobilized patient group as compared with the mobile group was 0.88 (95% Confidence Interval (CI) 0.33 to 2.13). When taking into account baseline characteristics, risk factors and death rates by various causes, no differences were found between the two groups. In conclusion, chronically immobile bedridden patients are no more prone to clinically overt venous thromboembolic events than institutionalized mobile patients. Until further studies are performed concerning the impact of very prolonged immobilization on the risk of VTE, there is no evidence to support primary prevention after the first three months of immobilization. Evidence for efficacy or cost effectiveness beyond this early period is not available.

Protein immobilization onto various surfaces using a polymer-bound isocyanate

NASA Astrophysics Data System (ADS)

Kang, Hyun-Jin; Cha, Eun Ji; Park, Hee-Deung

2015-01-01

Silane coupling agents have been widely used for immobilizing proteins onto inorganic surfaces. However, the immobilization method using silane coupling agents requires several treatment steps, and its application is limited to only surfaces containing hydroxyl groups. The aim of this study was to develop a novel method to overcome the limitations of the silane-based immobilization method using a polymer-bound isocyanate. Initially, polymer-bound isocyanate was dissolved in organic solvent and then was used to dip-coat inorganic surfaces. Proteins were then immobilized onto the dip-coated surfaces by the formation of urea bonds between the isocyanate groups of the polymer and the amine groups of the protein. The reaction was verified by FT-IR in which NCO stretching peaks disappeared, and CO and NH stretching peaks appeared after immobilization. The immobilization efficiency of the newly developed method was insensitive to reaction temperatures (4-50 °C), but the efficiency increased with reaction time and reached a maximum after 4 h. Furthermore, the method showed comparable immobilization efficiency to the silane-based immobilization method and was applicable to surfaces that cannot form hydroxyl groups. Taken together, the newly developed method provides a simple and efficient platform for immobilizing proteins onto surfaces.

Lipase immobilized on the hydrophobic polytetrafluoroethene membrane with nonwoven fabric and its application in intensifying synthesis of butyl oleate.

PubMed

Wang, Shu-Guang; Zhang, Wei-Dong; Li, Zheng; Ren, Zhong-Qi; Liu, Hong-Xia

2010-11-01

The synthesis of butyl oleate was studied in this paper with immobilized lipase. Five types of membrane were used as support to immobilize Rhizopus arrhizus lipase by following a procedure combining filtration and protein cross-linking. Results showed that hydrophobic polytetrafluoroethene membrane with nonwoven fabric (HO-PTFE-NF) was the favorite choice in terms of higher protein loading, activity, and specific activity of immobilized lipase. The factors including solvent polarity, lipase dosage, concentration, and molar ratio of substrate and temperature were found to have significant influence on conversion. Results showed that hexane (logP = 3.53) was a favorable solvent for the biosynthesis of butyl oleate in our studies. The optimal conditions were experimentally determined of 50 U immobilized lipase, molar ratio of oleic acid to butanol of 1.0, substrate concentration of 0.12 mol/L, temperature of 37 °C, and reaction time of 2 h. The conversion was beyond 91% and decreased slightly after 18 cycles. Lipase immobilization can improve the conversion and the repeated use of immobilized lipase relative to free lipase.

Study on immobilization of marine oil-degrading bacteria by carrier of algae materials.

PubMed

Zhang, Yiran; Gao, Wei; Lin, Faxiang; Han, Bin; He, Changfei; Li, Qian; Gao, Xiangxing; Cui, Zhisong; Sun, Chengjun; Zheng, Li

2018-05-18

This study investigated the immobilizations with of bacteria two kinds of algal materials, Enteromorpha residue and kelp residue. The lipophilicity of them were compared by diesel absorption rates. The immobilization efficiency of Bacillus sp. E3 was measured to evaluate whether these carriers would satisfy the requirement for biodegradation of oil spills. The bacteria were immobilized through adsorption with the sterilized and non-sterilized carriers to compare the differences between the two treatments. Oil degradation rates were determined using gravimetric and GC-MS methods. Results showed the absorption rates of Enteromorpha residue and kelp residue for diesel were 411 and 273% respectively and remained approximately 105 and 120% after 2 h of erosion in simulated seawater system. After immobilized of Bacillus sp. E3, the oil degradation rates of them were higher than 65% after 21 days biodegradations. GC-MS analysis showed that two immobilizations degraded higher than 70% of the total alkane and the total PAHs, whereas the free bacteria degraded 63% of the total alkane and 66% the total PAHs. And the bacteria immobilized with the carriers degraded more HMW-alkanes and HMW-PAHs than the free bacteria. The bacteria immobilized by non-sterilized kelp residue showed a considerably higher degradation rate than that using sterilized kelp residue. A considerably higher cells absorption rate of immobilization was obtained when using kelp residue, and the preparation of immobilization was low cost and highly efficient. The experiments show the two algae materials, especially the kelp residue, present potential application in bioremediation of marine oil spills.

Tests of commercial colour CMOS cameras for astronomical applications

NASA Astrophysics Data System (ADS)

Pokhvala, S. M.; Reshetnyk, V. M.; Zhilyaev, B. E.

2013-12-01

We present some results of testing commercial colour CMOS cameras for astronomical applications. Colour CMOS sensors allow to perform photometry in three filters simultaneously that gives a great advantage compared with monochrome CCD detectors. The Bayer BGR colour system realized in colour CMOS sensors is close to the astronomical Johnson BVR system. The basic camera characteristics: read noise (e^{-}/pix), thermal noise (e^{-}/pix/sec) and electronic gain (e^{-}/ADU) for the commercial digital camera Canon 5D MarkIII are presented. We give the same characteristics for the scientific high performance cooled CCD camera system ALTA E47. Comparing results for tests of Canon 5D MarkIII and CCD ALTA E47 show that present-day commercial colour CMOS cameras can seriously compete with the scientific CCD cameras in deep astronomical imaging.

The Zeeman effect in the (0,0) band of the A 7Pi-X 7Sigma(+) transition of manganese monohydride, MnH.

PubMed

Steimle, Timothy C; Wang, Hailing; Gengler, Jamie J; Stoll, Michael; Meijer, Gerard

2008-10-28

The Zeeman tuning of the P(1)(0) line (nu=17 568.35 cm(-1)) of the A (7)Pi-X (7)Sigma(+) (0,0) band of manganese monohydride, MnH, has been investigated. The laser induced fluorescence spectrum of a supersonic molecular beam sample was recorded at a resolution of approximately 40 MHz and with field strengths of up to 362.0 mT. The observed spectrum was successfully fitted using a traditional effective Zeeman Hamiltonian to determine an effective magnetic g-factor for the J=2 level of the F(1)-spin component of the A (7)Pi(v=0) state. Spectral predictions of the P(1)(0) line at field strengths used in magnetic trapping experiments are presented.

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.

Development of a new in-air micro-PIXE set-up with in-vacuum charge measurements in Atomki

NASA Astrophysics Data System (ADS)

Török, Zs.; Huszánk, R.; Csedreki, L.; Dani, J.; Szoboszlai, Z.; Kertész, Zs.

2015-11-01

A new external microbeam set-up has recently been installed as the extension of the existing microprobe system at the Laboratory of Ion Beam Applications of Atomki, Debrecen, Hungary. The external beam set-up, based on the system of Oxford Microbeams (OM), is equipped with two X-ray detectors for PIXE analysis, a digital microscope, two alignment lasers and a precision XYZ stage for easy and reproducible positioning of the sample. Exit windows with different thicknesses and of different materials can be used according to the actual demands, currently silicon-nitride (Si3N4) film with 200 nm thickness is employed in our laboratory. The first application was demonstrated in the field of archaeometry, on Bronze Age hoards from Hungary.

ALMA On the Move - ESO Awards Important Contract for the ALMA Project

NASA Astrophysics Data System (ADS)

2005-12-01

Only two weeks after awarding its largest-ever contract for the procurement of antennas for the Atacama Large Millimeter Array project (ALMA), ESO has signed a contract with Scheuerle Fahrzeugfabrik GmbH, a world-leader in the design and production of custom-built heavy-duty transporters, for the provision of two antenna transporting vehicles. These vehicles are of crucial importance for ALMA. ESO PR Photo 41a/05 ESO PR Photo 41a/05 The ALMA Transporter (Artist's Impression) [Preview - JPEG: 400 x 756 pix - 234k] [Normal - JPEG: 800 x 1512 pix - 700k] [Full Res - JPEG: 1768 x 3265 pix - 2.3M] Caption: Each of the ALMA transporters will be 10 m wide, 4.5 m high and 16 m long. "The timely awarding of this contract is most important to ensure that science operations can commence as planned," said ESO Director General Catherine Cesarsky. "This contract thus marks a further step towards the realization of the ALMA project." "These vehicles will operate in a most unusual environment and must live up to very strict demands regarding performance, reliability and safety. Meeting these requirements is a challenge for us, and we are proud to have been selected by ESO for this task," commented Hans-Jörg Habernegg, President of Scheuerle GmbH. ESO PR Photo 41b/05 ESO PR Photo 41b/05 Signing the Contract [Preview - JPEG: 400 x 572 pix - 234k] [Normal - JPEG: 800 x 1143 pix - 700k] [HiRes - JPEG: 4368 x 3056 pix - 2.3M] Caption: (left to right) Mr Thomas Riek, Vice-President of Scheuerle GmbH, Dr Catherine Cesarsky, ESO Director General and Mr Hans-Jörg Habernegg, President of Scheuerle GmbH. When completed on the high-altitude Chajnantor site in Chile, ALMA is expected to comprise more than 60 antennas, which can be placed in different locations on the plateau but which work together as one giant telescope. Changing the relative positions of the antennas and thus also the configuration of the array allows for different observing modes, comparable to using a zoom lens, offering different degrees of resolution and sky coverage as needed by the astronomers. The ALMA Antenna Transporters allow for moving the antennas between the different pre-defined antenna positions. They will also be used for transporting antennas between the maintenance area at 2900 m elevation and the "high site" at 5000 m above sea level, where the observations are carried out. Given their important functions, both for the scientific work and in transporting high-tech antennas with the required care, the vehicles must live up to very demanding operational requirements. Each transporter has a mass of 150 tonnes and is able to lift and transport antennas of 110 tonnes. They must be able to place the antennas on the docking pads with millimetric precision. At the same time, they must be powerful enough to climb 2000 m reliably and safely with their heavy and valuable load, putting extraordinary demands on the 500 kW diesel engines. This means negotiating a 28 km long high-altitude road with an average slope of 7 %. Finally, as they will be operated at an altitude with significantly reduced oxygen levels, a range of redundant safety devices protect both personnel and equipment from possible mishaps or accidents. The first transporter is scheduled to be delivered in the summer of 2007 to match the delivery of the first antennas to Chajnantor. The ESO contract has a value of approx. 5.5 m Euros.

VIMOS - a Cosmology Machine for the VLT

NASA Astrophysics Data System (ADS)

2002-03-01

Successful Test Observations With Powerful New Instrument at Paranal [1] Summary One of the most fundamental tasks of modern astrophysics is the study of the evolution of the Universe . This is a daunting undertaking that requires extensive observations of large samples of objects in order to produce reasonably detailed maps of the distribution of galaxies in the Universe and to perform statistical analysis. Much effort is now being put into mapping the relatively nearby space and thereby to learn how the Universe looks today . But to study its evolution, we must compare this with how it looked when it still was young . This is possible, because astronomers can "look back in time" by studying remote objects - the larger their distance, the longer the light we now observe has been underway to us, and the longer is thus the corresponding "look-back time". This may sound easy, but it is not. Very distant objects are very dim and can only be observed with large telescopes. Looking at one object at a time would make such a study extremely time-consuming and, in practical terms, impossible. To do it anyhow, we need the largest possible telescope with a highly specialised, exceedingly sensitive instrument that is able to observe a very large number of (faint) objects in the remote universe simultaneously . The VLT VIsible Multi-Object Spectrograph (VIMOS) is such an instrument. It can obtain many hundreds of spectra of individual galaxies in the shortest possible time; in fact, in one special observing mode, up to 6400 spectra of the galaxies in a remote cluster during a single exposure, augmenting the data gathering power of the telescope by the same proportion. This marvellous science machine has just been installed at the 8.2-m MELIPAL telescope, the third unit of the Very Large Telescope (VLT) at the ESO Paranal Observatory. A main task will be to carry out 3-dimensional mapping of the distant Universe from which we can learn its large-scale structure . "First light" was achieved on February 26, 2002, and a first series of test observations has successfully demonstrated the huge potential of this amazing facility. Much work on VIMOS is still ahead during the coming months in order to put into full operation and fine-tune the most efficient "galaxy cruncher" in the world. VIMOS is the outcome of a fruitful collaboration between ESO and several research institutes in France and Italy, under the responsibility of the Laboratoire d'Astrophysique de Marseille (CNRS, France). The other partners in the "VIRMOS Consortium" are the Laboratoire d'Astrophysique de Toulouse, Observatoire Midi-Pyrénées, and Observatoire de Haute-Provence in France, and Istituto di Radioastronomia (Bologna), Istituto di Fisica Cosmica e Tecnologie Relative (Milano), Osservatorio Astronomico di Bologna, Osservatorio Astronomico di Brera (Milano) and Osservatorio Astronomico di Capodimonte (Naples) in Italy. PR Photo 09a/02 : VIMOS image of the Antennae Galaxies (centre). PR Photo 09b/02 : First VIMOS Multi-Object Spectrum (full field) PR Photo 09c/02 : The VIMOS instrument on VLT MELIPAL PR Photo 09d/02 : The VIMOS team at "First Light". PR Photo 09e/02 : "First Light" image of NGC 5364 PR Photo 09f/02 : Image of the Crab Nebula PR Photo 09g/02 : Image of spiral galaxy NGC 2613 PR Photo 09h/02 : Image of spiral galaxy Messier 100 PR Photo 09i/02 : Image of cluster of galaxies ACO 3341 PR Photo 09j/02 : Image of cluster of galaxies MS 1008.1-1224 PR Photo 09k/02 : Mask design for MOS exposure PR Photo 09l/02 : First VIMOS Multi-Object Spectrum (detail) PR Photo 09m/02 : Integrated Field Spectroscopy of central area of the "Antennae Galaxies" PR Photo 09n/02 : Integrated Field Spectroscopy of central area of the "Antennae Galaxies" (detail) Science with VIMOS ESO PR Photo 09a/02 ESO PR Photo 09a/02 [Preview - JPEG: 400 x 469 pix - 152k] [Normal - JPEG: 800 x 938 pix - 408k] ESO PR Photo 09b/02 ESO PR Photo 09b/02 [Preview - JPEG: 400 x 511 pix - 304k] [Normal - JPEG: 800 x 1022 pix - 728k] Caption : PR Photo 09a/02 : One of the first images from the new VIMOS facility, obtained right after the moment of "first light" on Ferbruary 26, 2002. It shows the famous "Antennae Galaxies" (NGC 4038/39), the result of a recent collision between two galaxies. As an immediate outcome of this dramatic event, stars are born within massive complexes that appear blue in this composite photo, based on exposures through green, orange and red optical filtres. PR Photo 09b/02 : Some of the first spectra of distant galaxies obtained with VIMOS in Multi-Object-Spectroscopy (MOS) mode. More than 220 galaxies were observed simultaneously, an unprecedented efficiency for such a "deep" exposure, reaching so far out in space. These spectra allow to obtain the redshift, a measure of distance, as well as to assess the physical status of the gas and stars in each of these galaxies. A part of this photo is enlarged as PR Photo 09l/02. Technical information about these photos is available below. Other "First Light" images from VIMOS are shown in the photo gallery below. The next in the long series of front-line instruments to be installed on the ESO Very Large Telescope (VLT), VIMOS (and its complementary, infrared-sensitive counterpart NIRMOS, now in the design stage) will allow mapping of the distribution of galaxies, clusters, and quasars during a time interval spanning more than 90% of the age of the universe. It will let us look back in time to a moment only ~1.5 billion years after the Big Bang (corresponding to a redshift of about 5). Like archaeologists, astronomers can then dig deep into those early ages when the first building blocks of galaxies were still in the process of formation. They will be able to determine when most of the star formation occurred in the universe and how it evolved with time. They will analyse how the galaxies cluster in space, and how this distribution varies with time. Such observations will put important constraints on evolution models, in particular on the average density of matter in the Universe. Mapping the distant universe requires to determine the distances of the enormous numbers of remote galaxies seen in deep pictures of the sky, adding depth - the third, indispensible dimension - to the photo. VIMOS offers this capability, and very efficiently. Multi-object spectroscopy is a technique by which many objects are observed simultaneously. VIMOS can observe the spectra of about 1000 galaxies in one exposure, from which redshifts, hence distances, can be measured [2]. The possibility to observe two galaxies at once would be equivalent to having a telescope twice the size of a VLT Unit Telescope. VIMOS thus effectively "increases" the size of the VLT hundreds of times. From these spectra, the stellar and gaseous content and internal velocities of galaxies can be infered, forming the base for detailed physical studies. At present the distances of only a few thousand galaxies and quasars have been measured in the distant universe. VIMOS aims at observing 100 times more, over one hundred thousand of those remote objects. This will form a solid base for unprecedented and detailed statistical studies of the population of galaxies and quasars in the very early universe. The international VIRMOS Consortium VIMOS is one of two major astronomical instruments to be delivered by the VIRMOS Consortium of French and Italian institutes under a contract signed in the summer of 1997 between the European Southern Observatory (ESO) and the French Centre National de la Recherche Scientifique (CNRS). The participating institutes are: in France: * Laboratoire d'Astrophysique de Marseille (LAM), Observatoire Marseille-Provence (project responsible) * Laboratoire d'Astrophysique de Toulouse, Observatoire Midi-Pyrénées * Observatoire de Haute-Provence (OHP) in Italy: * Istituto di Radioastronomia (IRA-CNR) (Bologna) * Istituto di Fisica Cosmica e Tecnologie Relative (IFCTR) (Milano) * Osservatorio Astronomico di Capodimonte (OAC) (Naples) * Osservatorio Astronomico di Bologna (OABo) * Osservatorio Astronomico di Brera (OABr) (Milano) VIMOS at the VLT: a unique and powerful combination ESO PR Photo 09c/02 ESO PR Photo 09c/02 [Preview - JPEG: 501 x 400 pix - 312k] [Normal - JPEG: 1002 x 800 pix - 840k] Caption : PR Photo 09c/02 shows the new VIMOS instrument on one of the Nasmyth platforms of the 8.2-m VLT MELIPAL telescope at Paranal. VIMOS is installed on the Nasmyth "Focus B" platform of the 8.2-m VLT MELIPAL telescope, cf. PR Photo 09c/02 . It may be compared to four multi-mode instruments of the FORS-type (cf. ESO PR 14/98 ), joined in one stiff structure. The construction of VIMOS has involved the production of large and complex optical elements and their integration in more than 30 remotely controlled, finely moving functions in the instrument. In the configuration employed for the "first light", VIMOS made use of two of its four channels. The two others will be put into operation in the next commissioning period during the coming months. However, VIMOS is already now the most efficient multi-object spectrograph in the world , with an equivalent (accumulated) slit length of up to 70 arcmin on the sky. VIMOS has a field-of-view as large as half of the full moon (14 x 16 arcmin 2 for the four quadrants), the largest sky field to be imaged so far by the VLT. It has excellent sensitivity in the blue region of the spectrum (about 60% more efficient than any other similar instruments in the ultraviolet band), and it is also very sensitive in all other visible spectral regions, all the way to the red limit. But the absolutely unique feature of VIMOS is its capability to take large numbers of spectra simultaneously , leading to exceedingly efficient use of the observing time. Up to about 1000 objects can be observed in a single exposure in multi-slit mode. And no less than 6400 spectra can be recorded with the Integral Field Unit , in which a closely packed fibre optics bundle can simultaneously observe a continuous sky area measuring no less than 56 x 56 arcsec 2. A dedicated machine, the Mask Manufacturing Unit (MMU) , cuts the slits for the entrance apertures of the spectrograph. The laser is capable of cutting 200 slits in less than 15 minutes. This facility was put into operation at Paranal by the VIRMOS Consortium already in August 2000 and has since been extensively used for observations with the FORS2 instrument; more details are available in ESO PR 19/99. Fast start-up of VIMOS at Paranal ESO PR Photo 09d/02 ESO PR Photo 09d/02 [Preview - JPEG: 473 x 400 pix - 280k] [Normal - JPEG: 946 x 1209 pix - 728k] ESO PR Photo 09e/02 ESO PR Photo 09e/02 [Preview - JPEG: 400 x 438 pix - 176k] [Normal - JPEG: 800 x 876 pix - 664k] Caption : PR Photo 09d/02 : The VIRMOS team in the MELIPAL control room, moments after "First Light" on February 26, 2002. From left to right: Oreste Caputi, Marco Scodeggio, Giovanni Sciarretta , Olivier Le Fevre, Sylvie Brau-Nogue, Christian Lucuix, Bianca Garilli, Markus Kissler-Patig (in front), Xavier Reyes, Michel Saisse, Luc Arnold and Guido Mancini . PR Photo 09e/02 : The spiral galaxy NGC 5364 was the first object to be observed by VIMOS. This false-colour near-infrared, raw "First Light" photo shows the extensive spiral arms. Technical information about this photo is available below. VIMOS was shipped from Observatoire de Haute-Provence (France) at the end of 2001, and reassembled at Paranal during a first period in January 2002. From mid-February, the instrument was made ready for installation on the VLT MELIPAL telescope; this happened on February 24, 2002. VIMOS saw "First Light" just two days later, on February 26, 2000, cf. PR Photo 09e/02 . During the same night, a number of excellent images were obtained of various objects, demonstrating the fine capabilities of the instrument in the "direct imaging"-mode. The first spectra were successfully taken during the night of March 2 - 3, 2002 . The slit masks that were used on this occasion were prepared with dedicated software that also optimizes the object selection, cf. PR Photo 09k/02 , and were then cut with the laser machine. From the first try on, the masks have been well aligned on the sky objects. The first observations with large numbers of spectra were obtained shortly thereafter. First accomplishments Images of nearby galaxies, clusters of galaxies, and distant galaxy fields were among the first to be obtained, using the VIMOS imaging mode and demonstrating the excellent efficiency of the instrument, various examples are shown below. The first observations of multi-spectra were performed in a selected sky field in which many faint galaxies are present; it is known as the "VIRMOS-VLT Deep Survey Field at 1000+02". Thanks to the excellent sensitivity of VIMOS, the spectra of galaxies as faint as (red) magnitude R = 23 (i.e. over 6 million times fainter than what can be perceived with the unaided eye) are visible on exposures lasting only 15 minutes. Some of the first observations with the Integral Field Unit were made of the core of the famous Antennae Galaxies (NGC 4038/39) . They will form the basis for a detailed map of the strong emission produced by the current, dramatic collision of the two galaxies. First Images and Spectra from VIMOS - a Gallery The following photos are from a collection of the first images and spectra obtained with VIMOS . See also PR Photos 09a/02 , 09b/02 and 09e/02 , reproduced above. Technical information about all of them is available below. ESO PR Photo 09f/02 ESO PR Photo 09f/02 [Preview - JPEG: 400 x 469 pix - 224k] [Normal - JPEG: 800 x 937 pix - 544k] [HiRes - JPEG: 2001 x 2343 pix - 3.6M] Caption : PR Photo 09f/02 : The Crab Nebula (Messier 1) , as observed by VIMOS. This well-known object is the remnant of a stellar explosion in the year 1054. ESO PR Photo 09g/02 ESO PR Photo 09g/02 [Preview - JPEG: 478 x 400 pix - 184k] [Normal - JPEG: 956 x 1209 pix - 416k] [HiRes - JPEG: 1801 x 1507 pix - 1.4M] Caption : PR Photo 09g/02 : VIMOS photo of NGC 2613 , a spiral galaxy that ressembles our own Milky Way. ESO PR Photo 09h/02 ESO PR Photo 09h/02 [Preview - JPEG: 400 x 469 pix - 152k] [Normal - JPEG: 800 x 938 pix - 440k] [HiRes - JPEG: 1800 x 2100 pix - 2.0M] Caption : PR Photo 09h/02 : Messier 100 is one of the largest and brightest spiral galaxies in the sky. ESO PR Photo 09i/02 ESO PR Photo 09i/02 [Preview - JPEG: 400 x 405 pix - 144k] [Normal - JPEG: 800 x 810 pix - 312k] Caption : PR Photo 09i/02 : The cluster of galaxies ACO 3341 is located at a distance of about 300 million light-years (redshift z = 0.037), i.e., comparatively nearby in cosmological terms. It contains a large number of galaxies of different size and brightness that are bound together by gravity. ESO PR Photo 09j/02 ESO PR Photo 09j/02 [Preview - JPEG: 447 x 400 pix - 200k] [Normal - JPEG: 893 x 800 pix - 472k] [HiRes - JPEG: 1562 x 1399 pix - 1.1M] Caption : PR Photo 09j/02 : The distant cluster of galaxies MS 1008.1-1224 is some 3 billion light-years distant (redshift z = 0.301). The galaxies in this cluster - that we observe as they were 3 billion years ago - are different from galaxies in our neighborhood; their stellar populations, on the average, are younger. ESO PR Photo 09k/02 ESO PR Photo 09k/02 [Preview - JPEG: 400 x 455 pix - 280k] [Normal - JPEG: 800 x 909 pix - 696k] Caption : PR Photo 09k/02 : Design of a Mask for Multi-Object Spectroscopy (MOS) observations with VIMOS. The mask serves to block, as far as possible, unwanted background light from the "night sky" (radiation from atoms and molecules in the Earth's upper atmosphere). During the set-up process for multi-object observations, the VIMOS software optimizes the position of the individual slits in the mask (one for each object for which a spectrum will be obtained) before these are cut. The photo shows an example of this fitting process, with the slit contours superposed on a short pre-exposure of the sky field to be observed. ESO PR Photo 09l/02 ESO PR Photo 09l/02 [Preview - JPEG: 470 x 400 pix - 200k] [Normal - JPEG: 939 x 800 pix - 464k] Caption : PR Photo 09l/02 : First Multi-Object Spectroscopy (MOS) observations with VIMOS; enlargement of a small part of the field shown in PR Photo 09b/02. The light from each galaxy passes through the dedicated slit in the mask (see PR Photo 09k/02 ) and produces a spectrum on the detector. Each vertical rectangle contains the spectrum of one galaxy that is located several billion light-years away. The horizontal lines are the strong emission from the "night sky" (radiation from atoms and molecules in the Earth's upper atmosphere), while the vertical traces are the spectral signatures of the galaxies. The full field contains the spectra of over 220 galaxies that were observed simultaneously, illustrating the great efficiency of this technique. Later, about 1000 spectra will be obtained in one exposure. ESO PR Photo 09m/02 ESO PR Photo 09m/02 [Preview - JPEG: 470 x 400 pix - 264k] [Normal - JPEG: 939 x 800 pix - 720k] Caption : PR Photo 09m/02 : was obtained with the Integral Field Spectroscopy mode of VIMOS. In one single exposure, more than 3000 spectra were taken of the central area of the Antennae Galaxies ( PR Photo 09a/02 ). ESO PR Photo 09n/02 ESO PR Photo 09n/02 [Preview - JPEG: 532 x 400 pix - 320k] [Normal - JPEG: 1063 x 800 pix - 864k] Caption : PR Photo 09n/02 : An enlargement of a small area in PR Photo 09m/02. This observation allows mapping of the distribution of elements like hydrogen (H) and sulphur (S II), for which the signatures are clearly identified in these spectra. The wavelength increases towards the top (arrow). Notes [1]: This is a joint Press Release of ESO , Centre National de la Recherche Scientifique (CNRS) in France, and Consiglio Nazionale delle Ricerche (CNR) and Istituto Nazionale di Astrofisica (INAF) in Italy. [2]: In astronomy, the redshift denotes the fraction by which the lines in the spectrum of an object are shifted towards longer wavelengths. The observed redshift of a distant galaxy gives a direct estimate of the apparent recession velocity as caused by the universal expansion. Since the expansion rate increases with distance, the velocity is itself a function (the Hubble relation) of the distance to the object. Technical information about the photos PR Photo 09a/01 : Composite VRI image of NGC 4038/39, obtained on 26 February 2002, in a bright sky (full moon). Individual exposures of 60 sec each; image quality 0.6 arcsec FWHM; the field measures 3.5 x 3.5 arcmin 2. North is up and East is left. PR Photo 09b/02 : MOS-spectra obtained with two quadrants totalling 221 slits + 6 reference objects (stars placed in square holes to ensure a correct alignment). Exposure time 15 min; LR(red) grism. This is the raw (unprocessed) image of the spectra. PR Photo 09e/02 : A 60 sec i exposure of NGC 5364 on February 26, 2002; image quality 0.6 arcsec FWHM; full moon; 3.5 x 3.5 arcmin 2 ; North is up and East is left. PR Photo 09f/02 : Composite VRI image of Messier 1, obtained on March 4, 2002. The individual exposures lasted 180 sec; image quality 0.7 arcsec FWHM; field 7 x 7 arcmin 2 ; North is up and East is left. PR Photo 09g/02 : Composite VRI image of NGC 2613, obtained on February 28, 2002. The individual exposures lasted 180 sec; image quality 0.7 arcsec FWHM; field 7 x 7 arcmin 2 ; North is up and East is left. PR Photo 09h/02 : Composite VRI image of Messier 100, obtained on March 3, 2002. The individual exposures lasted 180 sec, image quality 0.7 arcsec FWHM; field 7 x 7 arcmin 2 ; North is up and East is left. PR Photo 09i/02 : R-band image of galaxy cluster ACO 3341, obtained on March 4, 2002. Exposure 300 sec, image quality 0.5 arcsec FWHM;. field 7 x 7 arcmin 2 ; North is up and East is left. PR Photo 09j/02 : Composite VRI image of the distant cluster of galaxies MS 1008.1-1224. The individual exposures lasted 300 sec; image quality 0.8 arcsec FWHM; field 5 x 3 arcmin 2 ; North is to the right and East is up. PR Photo 09k/02 : Mask design made with the VMMPS tool, overlaying a pre-image. The selected objects are seen at the centre of the yellow squares, where a 1 arcsec slit is cut along the spatial X-axis. The rectangles in white represent the dispersion in wavelength of the spectra along the Y-axis. Masks are cut with the Mask Manufacturing Unit (MMU) built by the Virmos Consortium. PR Photo 09l/02 : Enlargement of a small area of PR Photo 09b/02. PR Photo 09m/02 : Spectra of the central area of NGC 4038/39, obtained with the Integral Field Unit on February 26, 2002. The exposure lasted 5 min and was made with the low resolution red grating. PR Photo 09m/02 : Zoom-in on small area of PR Photo 09m/02. The strong emission lines of hydrogen (H-alpha) and ionized sulphur (S II) are seen.

Combined of ultrasound irradiation with high hydrostatic pressure (US/HHP) as a new method to improve immobilization of dextranase onto alginate gel.

PubMed

Bashari, Mohanad; Abbas, Shabbar; Xu, Xueming; Jin, Zhengyu

2014-07-01

In this research work, dextranase was immobilized onto calcium alginate beads by the combination of ultrasonic irradiation and high hydrostatic pressure (US/HHP) treatments. Effects of US/HHP treatments on loading efficiency and immobilization yield of dextranase enzyme onto calcium alginate beads were investigated. Furthermore, the activities of immobilized enzymes prepared with and without US/HHP treatments and that prepared with ultrasonic irradiation (US) and high hydrostatic pressure (HHP), as a function of pH, temperature, recyclability and enzyme kinetic parameters, were compared with that for free enzyme. The maximum loading efficiency and the immobilization yield were observed when the immobilized dextranase was prepared with US (40 W at 25 kHz for 15 min) combined with HHP (400 MPa for 15 min), under which the loading efficiency and the immobilization yield increased by 88.92% and 80.86%, respectively, compared to immobilized enzymes prepared without US/HHP treatment. On the other hand, immobilized enzyme prepared with US/HHP treatment showed Vmax, KM, catalytic and specificity constants values higher than that for the immobilized enzyme prepared with HHP treatment, indicated that, this new US/HHP method improved the catalytic kinetics activity of immobilized dextranase at all the reaction conditions studied. Compared to immobilized enzyme prepared either with US or HHP, the immobilized enzymes prepared with US/HHP method exhibited a higher: pH optimum, optimal reaction temperature, thermal stability and recyclability, and lower activation energy, which, illustrating the effectiveness of the US/HHP method. These results indicated that, the combination of US and HHP treatments could be an effective method for improving the immobilization of enzymes in polymers. Copyright © 2014 Elsevier B.V. All rights reserved.

Visible and UV-curable chitosan derivatives for immobilization of biomolecules.

PubMed

Kim, Eun-Hye; Han, Ga-Dug; Kim, Jae-Won; Noh, Seung-Hyun; Lee, Jae-Gwan; Ito, Yoshihiro; Son, Tae-Il

2017-11-01

Chitosan, which has many biocompatible properties, is used widely in medical field like wound healing, drug delivery and so on. Chitosan could be used as a biomaterial to immobilize protein-drug. There are many methods to immobilize protein-drug, but they have some drawbacks such as low efficiency and denaturation of protein. Therefore, photo-immobilization method is suggested to immobilize protein-drug. Photo-immobilization method is simple-reaction and also needs no additional crosslinking reagent. There has been some effort to modify chitosan to have an ability of photo-immobilization. Generally, visible and UV light reactive chitosan derivatives were prepared. Various types of photo-curable chitosan derivatives showed possibility for application to medical field. For example, they showed ability for protein-immobilization and some of them showed wound-healing effect, anti-adhesive effect, or property to interact directly with titanium surface. In this study, we introduce many types of photo-curable chitosan derivative and their possibility of medical application. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of free and immobilized Aspergillus niger NRC1ami pectinase applicable in industrial processes.

PubMed

Esawy, Mona A; Gamal, Amira A; Kamel, Zeinat; Ismail, Abdel-Mohsen S; Abdel-Fattah, Ahmed F

2013-02-15

The Aspergillus niger NRC1ami pectinase was evaluated according to its hydrolysis efficiency of dry untreated orange peels (UOP), HCl-treated orange peels and NaOH-treated orange peels (HOP and NOP). Pectinase was entrapped in polyvinyl alcohol (PVA) sponge and the optimum pH and temperature of the free and immobilized enzymes were shifted from 4, 40 °C to 6, 50 °C respectively. The study of pH stability of free and immobilized pectinase showed that the immobilization process protected the enzyme strongly from severe alkaline pHs. The immobilization process improved the enzyme thermal stability to great instant. The unique feature of the immobilization process is its ability to solve the orange juice haze problem completely. Immobilized enzyme was reused 12 times in orange juice clarification with 9% activity loss from the original activity. Maximum reaction rate (V(max)) and Michaelis-Menten constant (K(m)) of the partially purified form were significantly changed after immobilization. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis of cubic Ia-3d mesoporous silica in anionic surfactant templating system with the aid of acetate.

PubMed

Deng, Shao-Xin; Xu, Xue-Yan; He, Wen-Chao; Wang, Jin-Gui; Chen, Tie-Hong

2014-08-01

Mesoporous silica with three-dimensional (3D) bicontinuous cubic Ia-3d structure and fascinating caterpillar-like morphology was synthesized by using anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as the template and 3-amionpropyltrimethoxysilane (APS) as the co-structure-directing agent (CSDA) with the aid of acetate. A phase transformation from high interfacial curvature 2D hexagonal to low interfacial curvature 3D cubic Ia-3d occurred in the presence of a proper amount of acetate. Other species of salts (excluding acetate) had the ability to induce the caterpillar-like morphology, but failed to induce the cubic Ia-3d mesostructure. Furthermore, [3-(2-aminoethyl)-aminopropyl]trimethoxysilane (DAPS) was also used as the CSDA to synthesize Ia-3d mesostructured silica under the aid of sodium acetate. After extraction of the anionic surfactants, amino and di-amine functionalized 3D bicontinuous cubic Ia-3d mesoporous silicas were obtained and used as supports to immobilize Pd nanoparticles for supported catalysts. The catalytic activity of the catalysts was tested by catalytic hydrogenation of allyl alcohol. Copyright © 2013 Elsevier Inc. All rights reserved.

Effects of immobilization on articular cartilage: Autohistoradiographic findings with S35

NASA Technical Reports Server (NTRS)

Digiovanni, C.; Desantis, E.

1980-01-01

The effect of immobilization on the articular cartilage of rabbits was studied by light microscope. The knee joint of each rabbit was immobilized in a plaster in a position midway between flexion and extension for a 10 to 120 days period. Degenerative changes in the articular cartilage of increasing severity were observed. The fixation of the labeled SO4 by cartilage cells was decreased in advanced immobilization.

Degradation of Carbazole by Microbial Cells Immobilized in Magnetic Gellan Gum Gel Beads▿

PubMed Central

Wang, Xia; Gai, Zhonghui; Yu, Bo; Feng, Jinhui; Xu, Changyong; Yuan, Yong; Lin, Zhixin; Xu, Ping

2007-01-01

Polycyclic aromatic heterocycles, such as carbazole, are environmental contaminants suspected of posing human health risks. In this study, we investigated the degradation of carbazole by immobilized Sphingomonas sp. strain XLDN2-5 cells. Four kinds of polymers were evaluated as immobilization supports for Sphingomonas sp. strain XLDN2-5. After comparison with agar, alginate, and κ-carrageenan, gellan gum was selected as the optimal immobilization support. Furthermore, Fe3O4 nanoparticles were prepared by a coprecipitation method, and the average particle size was about 20 nm with 49.65-electromagnetic-unit (emu) g−1 saturation magnetization. When the mixture of gellan gel and the Fe3O4 nanoparticles served as an immobilization support, the magnetically immobilized cells were prepared by an ionotropic method. The biodegradation experiments were carried out by employing free cells, nonmagnetically immobilized cells, and magnetically immobilized cells in aqueous phase. The results showed that the magnetically immobilized cells presented higher carbazole biodegradation activity than nonmagnetically immobilized cells and free cells. The highest biodegradation activity was obtained when the concentration of Fe3O4 nanoparticles was 9 mg ml−1 and the saturation magnetization of magnetically immobilized cells was 11.08 emu g−1. Additionally, the recycling experiments demonstrated that the degradation activity of magnetically immobilized cells increased gradually during the eight recycles. These results support developing efficient biocatalysts using magnetically immobilized cells and provide a promising technique for improving biocatalysts used in the biodegradation of not only carbazole, but also other hazardous organic compounds. PMID:17827304

Preventive Effects of the Dietary Intake of Medium-chain Triacylglycerols on Immobilization-induced Muscle Atrophy in Rats.

PubMed

Nishimura, Shuhei; Inai, Makoto; Takagi, Tetsuo; Nonaka, Yudai; Urashima, Shogo; Honda, Kazumitsu; Aoyama, Toshiaki; Terada, Shin

2017-08-01

Previous studies have shown that medium-chain triacylglycerols (MCTs) exert favorable effects on protein metabolism. This study evaluated the effects of the dietary intake of MCTs on rat skeletal muscle mass and total protein content during casting-induced hindlimb immobilization, which causes substantial protein degradation and muscle atrophy. Rats were fed a standard diet containing long-chain triacylglycerols (LCTs) or MCTs for 3 days and then a unilateral hindlimb was immobilized while they received the same diet. After immobilization for 3, 7, and 14 days, muscle mass and total protein content in immobilized soleus muscle in the LCT-fed rats had markedly decreased compared to the contralateral muscle; however, these losses were partially suppressed in MCT-fed rats. Autophagosomal membrane proteins (LC-I and -II), which are biomarkers of autophagy-lysosome activity, did not differ significantly between the LCT- and MCT-fed rats. In contrast, the immobilization-induced increase in muscle-specific E3 ubiquitin ligase MuRF-1 protein expression in immobilized soleus muscle relative to contralateral muscle was completely blocked in the MCT-fed rats and was significantly lower than that observed in the LCT-fed rats. Collectively, these results indicate that the dietary intake of MCTs at least partly alleviates immobilization-induced muscle atrophy by inhibiting the ubiquitin-proteasome pathway.

Enhancement of algicidal properties of immobilized Bacillus methylotrophicus ZJU by coating with magnetic Fe₃O₄ nanoparticles and wheat bran.

PubMed

Sun, Pengfei; Hui, Cai; Wang, Sheng; Khan, Rashid Azim; Zhang, Qichun; Zhao, Yu-Hua

2016-01-15

Algicidal bacteria offer a promising option for killing cyanobacteria. In this study, a newly isolated strain of Bacillus methylotrophicus, ZJU, was used to control Microcystis aeruginosa. Analyses of relative reactive oxygen level, malondialdehyde content, superoxide dismutase activity, and fluorescence staining indicated that oxidative damage caused by the algicidal supernatant of strain ZJU mainly affected the cell membrane and consequently the membrane permeability and membrane potential of M. aeruginosa cells. Furthermore, an embedded immobilization technique was employed to improve the practical application of strain ZJU as an algicidal agent. On this basis, we proposed a novel concept of enhancing the algicidal properties of immobilized ZJU by adding Fe3O4 nanoparticles and wheat bran in the process of immobilization. Our studies showed that Fe3O4 nanoparticles conferred the immobilized bacteria with a magnetization of 30.87 emu/g, and this magnetization enabled efficient re-collection of the immobilized bacteria by magnetic means. Moreover, wheat bran endowed the immobilized bacteria with 10.34% higher algicidal activity than immobilized bacteria without wheat bran. The results indicate a novel concept of enhancing the algicidal property of bacteria against M. aeruginosa by adding Fe3O4 nanoparticles and wheat bran. Copyright © 2015 Elsevier B.V. All rights reserved.

Degradation of complex carbohydrate: immobilization of pectinase from Bacillus licheniformis KIBGE-IB21 using calcium alginate as a support.

PubMed

Rehman, Haneef Ur; Aman, Afsheen; Silipo, Alba; Qader, Shah Ali Ul; Molinaro, Antonio; Ansari, Asma

2013-08-15

Pectinases are heterogeneous group of enzymes that catalyse the hydrolysis of pectin substances which is responsible for the turbidity and undesirable cloudiness in fruits juices. In current study, partially purified pectinase from Bacillus licheniformis KIBGE-IB21 was immobilized in calcium alginate beads. The effect of sodium alginate and calcium chloride concentration on immobilization was studied and it was found that the optimal sodium alginate and calcium chloride concentration was 3.0% and 0.2 M, respectively. It was found that immobilization increases the optimal reaction time for pectin degradation from 5 to 10 min and temperature from 45 to 55°C, whereas, the optimal pH remained same with reference to free enzyme. Thermal stability of enzyme increased after immobilization and immobilized pectinase retained more than 80% of its initial activity after 5 days at 30°C as compared with free enzyme which showed only 30% of residual activity. The immobilized enzyme also exhibited good operational stability and 65% of its initial activity was observed during third cycle. In term of pectinase immobilization efficiency and stability, this calcium alginate beads approach seemed to permit good results and can be used to make a bioreactor for various applications in food industries. Copyright © 2013 Elsevier Ltd. All rights reserved.

Prehospital spine immobilization/spinal motion restriction in penetrating trauma: A practice management guideline from the Eastern Association for the Surgery of Trauma (EAST).

PubMed

Velopulos, Catherine G; Shihab, Hasan M; Lottenberg, Lawrence; Feinman, Marcie; Raja, Ali; Salomone, Jeffrey; Haut, Elliott R

2018-05-01

Spine immobilization in trauma has remained an integral part of most emergency medical services protocols despite a lack of evidence for efficacy and concern for associated complications, especially in penetrating trauma patients. We reviewed the published evidence on the topic of prehospital spine immobilization or spinal motion restriction in adult patients with penetrating trauma to structure a practice management guideline. We conducted a Cochrane style systematic review and meta-analysis and applied Grading of Recommendations, Assessment, Development, and Evaluation methodology to construct recommendations. Qualitative and quantitative analyses were used to evaluate the literature on the critical outcomes of mortality, neurologic deficit, and potentially reversible neurologic deficit. A total of 24 studies met inclusion criteria, with qualitative review conducted for all studies. We used five studies for the quantitative review (meta-analysis). No study showed benefit to spine immobilization with regard to mortality and neurologic injury, even for patients with direct neck injury. Increased mortality was associated with spine immobilization, with risk ratio [RR], 2.4 (confidence interval [CI], 1.07-5.41). The rate of neurologic injury or potentially reversible injury was very low, ranging from 0.002 to 0.076 and 0.00034 to 0.055, with no statistically significant difference for neurologic deficit or potentially reversible deficit, RR, 4.16 (CI, 0.56-30.89), and RR, 1.19 (CI, 0.83-1.70), although the point estimates favored no immobilization. Spine immobilization in penetrating trauma is associated with increased mortality and has not been shown to have a beneficial effect on mitigating neurologic deficits, even potentially reversible neurologic deficits. We recommend that spine immobilization not be used routinely for adult patients with penetrating trauma. Systematic review with meta-analysis study, level III.

A Cosmic Baby-Boom

NASA Astrophysics Data System (ADS)

2005-09-01

Large Population of Galaxies Found in the Young Universe with ESO's VLT The Universe was a more fertile place soon after it was formed than has previously been suspected. A team of French and Italian astronomers [1] made indeed the surprising discovery of a large and unknown population of distant galaxies observed when the Universe was only 10 to 30% its present age. ESO PR Photo 29a/05 ESO PR Photo 29a/05 New Population of Distant Galaxies [Preview - JPEG: 400 x 424 pix - 191k] [Normal - JPEG: 800 x 847 pix - 449k] [HiRes - JPEG: 2269 x 2402 pix - 2.0M] ESO PR Photo 29b/05 ESO PR Photo 29b/05 Average Spectra of Distant Galaxies [Preview - JPEG: 400 x 506 pix - 141k] [Normal - JPEG: 800 x 1012 pix - 320k] This breakthrough is based on observations made with the Visible Multi-Object Spectrograph (VIMOS) as part of the VIMOS VLT Deep Survey (VVDS). The VVDS started early 2002 on Melipal, one of the 8.2-m telescopes of ESO's Very Large Telescope Array [2]. In a total sample of about 8,000 galaxies selected only on the basis of their observed brightness in red light, almost 1,000 bright and vigorously star forming galaxies were discovered that were formed between 9 and 12 billion years ago (i.e. about 1,500 to 4,500 million years after the Big Bang). "To our surprise, says Olivier Le Fèvre, from the Laboratoire d'Astrophysique de Marseille (France) and co-leader of the VVDS project, "this is two to six times higher than had been found previously. These galaxies had been missed because previous surveys had selected objects in a much more restrictive manner than we did. And they did so to accommodate the much lower efficiency of the previous generation of instruments." While observations and models have consistently indicated that the Universe had not yet formed many stars in the first billion years of cosmic time, the discovery announced today by scientists calls for a significant change in this picture. The astronomers indeed find that stars formed two to three times faster than previously estimated. "These observations will demand a profound reassessment of our theories of the formation and evolution of galaxies in a changing Universe", says Gianpaolo Vettolani, the other co-leader of the VVDS project, working at INAF-IRA in Bologna (Italy). These results are reported in the September 22 issue of the journal Nature (Le Fèvre et al., "A large population of galaxies 9 to 12 billion years back in the life of the Universe").

Influence of Immobilized Biomolecules on Magnetic Bead Plug Formation and Retention in Capillary Electrophoresis

PubMed Central

Henken, Rachel L.; Chantiwas, Rattikan; Gilman, S. Douglass

2012-01-01

Significant changes in the formation and retention of magnetic bead plugs in a capillary during electrophoresis were studied, and it was demonstrated that these effects were due to the type of biological molecule immobilized on the surface of these beads. Three biological molecules, an antibody, an oligonucleotide and alkaline phosphatase, were attached to otherwise identical streptavidin-coated magnetic beads through biotin-avidin binding in order to isolate differences in bead immobilization in a magnetic field resulting from the type of biological molecule immobilized on the bead surface. Alkaline phosphatase also was attached to the magnetic beads using epoxy groups on the bead surfaces (instead of avidin-biotin binding) to study the impact of immobilization chemistry. The formation and retention of magnetic bead plugs were studied quantitatively using light scattering detection of magnetic particles eluting from the bead plugs and qualitatively using microscopy. Both the type of biomolecule immobilized on the magnetic bead surface and the chemistry used to link the biomolecule to the magnetic bead impacted the formation and retention of the bead plugs. PMID:22437880

[On the use of FTA technology for collection, archieving, and molecular analysis of microsporidia dna from clinical stool samples].

PubMed

Sokolova, O I; Dem'ianov, A V; Bovers, L S; Did'e, E S; Sokolova, Iu Ia

2011-01-01

The FTA technology was applied for sampling, archiving, and molecular analysis of the DNA isolated from stool samples to diagnose and identify microsporidia, the intracellular opportunistic parasites which induce malabsortion syndrome in immunosuppressed humans, particularly in patients with AIDS. Microsporidia DNA was successfully amplified in 6 of 50 stool samples of HIV-positive patients of the S. P. Botkin Memorial Infectious Disease Hospital (St. Petersburg) applied to FTA cards (FTA-Cars, Whatman Inc. Florham Park, NJ, USA). Amplicons (the fragments of rDNA) were directly sequenced, and microsporidia species--Encephalitozoon intestinalis, E. cuniculi, E. hellem, and Enterocytozoon bieneusi--were identified in Genbank by NCBI BLAST program. The FTA method of DNA immobilization is especially promising for epidemiological and field population studies which involve genotyping of microsporidia species and isolates.

Effect of temperature and mixing speed on immobilization of crude enzyme from Aspergillus niger on chitosan for hydrolyzing cellulose

NASA Astrophysics Data System (ADS)

Hamzah, Afan; Gek Ela Kumala, P.; Ramadhani, Dwi; Maziyah, Nurul; Rahmah, Laila Nur; Soeprijanto, Widjaja, Arief

2017-05-01

Conversion of cellulose into reducing sugar through enzymatic hydrolysis has advantageous because it produces greater product yield, higher selectivity, require less energy, more moderate operating conditions and environment friendly. However, the nature of the enzyme that is difficult to separate and its expensive price become an obstacle. These obstacles can be overcome by immobilizing the enzyme on chitosan material so that the enzyme can be reused. Chitosan is chosen because it is cheap, inert, hydrophilic, and biocompatible. In this research, we use covalent attachment and combination between covalent attachment and cross-linking method for immobilizing crude enzyme. This research was focusing in study of Effect of temperature and mixing speed on Immobilization Enzyme From Aspergillus Niger on Chitosan For Hydrolyzing both soluble (Carboxymethylcellulose) and insoluble Cellulose (coconut husk). This Research was carried out by three main step. First, coconut husk was pre-treated mechanically and chemically, Second, Crude enzyme from Aspergillus niger strain was immobilized on chitosan in various immobilization condition. At last, the pre-treated coconut husk and Carboxymetylcellulose (CMC) were hydrolyzed by immobilized cellulose on chitosan for reducing sugar production. The result revealed that the most reducing sugar produced by immobilized enzyme on chitosan+GDA with immobilization condition at 30 °C and 125 rpm. Enzyme immobilized on chitosan cross-linked with GDA produced more reducing sugar from preteated coconut husk than enzyme immobilized on chitosan.

Preparation, characterization, and luminescence of (SBA-15) immobilized pepsin

NASA Astrophysics Data System (ADS)

Zhai, Qing-Zhou; Sun, Si-Jia

2014-12-01

SBA-15 mesoporous silica was synthesized by hydrothermal method and its surface was methylated by treatment with methyltrimethoxysilane. Pepsin was immobilized on the obtained materials giving host-guest composite materials (SBA-15)-pepsin and (methylated SBA-15)-pepsin. The optimum conditions for preparation of these materials were established. Methylated SBA-15 (M-SBA-15) has improved immobilization efficiency of enzyme compared to initial SBA-15 silica. It was shown that with the gradual increase of NaCl solution ionic strength the immobilized amount of enzyme was reduced. Powder X-ray diffraction and Fourier transform infrared spectroscopy showed that the host frameworks in the prepared host-guest composite materials are intact and the ordered structure was retained. Scanning electron microscopic studies revealed fibrous morphologic characteristics of the SBA-15 and the immobilized pepsin composite materials. The average particle diameter of (SBA-15)-pepsin composite was 338 ± 10 and 343 ± 10 nm for (M-SBA-15)-pepsin. The low temperature N2 adsorption-desorption study at 77 K showed that the pore sizes and specific surface areas of the host-guest composite materials were smaller than those before the introduction of the enzyme, suggesting that the immobilized enzyme occupied a definite position in the host material pore channels. The UV-vis solid diffuse reflectance and luminescence studies showed that the enzyme was successfully immobilized on to the host material and that after the immobilization of enzyme on SBA-15 the conformation of pepsin macromolecule has not been changed.

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.

Metabolic alkalosis during immobilization in monkeys (M. nemestrina)

NASA Technical Reports Server (NTRS)

Young, D. R.; Yeh, I.; Swenson, R. S.

1983-01-01

The systemic and renal acid-base response of monkeys during ten weeks of immobilization was studied. By three weeks of immobilization, arterial pH and bicarbonate concentrations were elevated (chronic metabolic alkalosis). Net urinary acid excretion increased in immobilized animals. Urinary bicarbonate excretion decreased during the first three weeks of immobilization, and then returned to control levels. Sustained increases in urinary ammonium excretion were seen throughout the time duration of immobilization. Neither potassium depletion nor hypokalemia was observed. Most parameters returned promptly to the normal range during the first week of recovery. Factors tentatively associated with changes in acid-base status of monkeys include contraction of extracellular fluid volume, retention of bicarbonate, increased acid excretion, and possible participation of extrarenal buffers.

Immobilization of bacterial proteases on water-solved polymer by means of electron beam

NASA Astrophysics Data System (ADS)

Gonchar, A. M.; Auslender, V. L.

1996-12-01

Possibility of electron beam usage for proteases' immobilization on 1,4-polyalkylene oxide (1,4-PAO) was studied to obtain biologically active complex for multi-purpose usage. It is shown that immobilization of Bacillus Subtilis protease takes place due to free-radical linking of enzyme and carrier with formation of mycellium-like structures. Immobilization improves heat resistance of enzyme up to 60°C without substrate and up to 80°C in presence of substrate, widens range of pH activity in comparison with non-immobilized forms. Immobilized proteases do not contain peroxides or long-live radicals. Our results permitted to create technologies for production of medical and veterinary preparations, active components for wool washing agents and leather fabrication technology.

Pineapple stem bromelain immobilized on different supports: catalytic properties in model wine.

PubMed

Ilaria, Benucci; Marco, Esti; Katia, Liburdi; Maria Vittoria, Garzillo Anna

2012-01-01

Bromelain from pineapple stem has been covalently immobilized on different supports to select the more efficient biocatalyst that should be applied toward unstable proteins in real white wine. In this preliminary study, catalytic properties of different immobilized bromelain forms were compared under wine-like conditions, against a synthetic substrate (Bz-Phe-Val-Arg-pNA).Covalent immobilization affected protease kinetic properties, even if all immobilized forms presented both a better substrate affinity and higher half-life (with the exception of a few procedures) with respect to the free enzyme. Stem bromelain was successfully immobilized on chitosan beads without glutaraldehyde thus yielding a food-safe and promising biocatalyst for unstable real wine future application. Copyright © 2012 American Institute of Chemical Engineers (AIChE).

Effect of linoleic-acid modified carboxymethyl chitosan on bromelain immobilization onto self-assembled nanoparticles

NASA Astrophysics Data System (ADS)

Tan, Yu-long; Liu, Chen-guang; Yu, Le-jun; Chen, Xi-guang

2008-06-01

Hydrogel nanoparticles could be prepared by using linoleic acid (LA) modified carboxymethyl chitosan (CMCS) after sonication. Bromelain could be loaded onto nanoparticles of LA-CMCS. Factors affecting the activity of the immobilized enzyme, including temperature, storage etc., were investigated in this study. The results showed that the stability of bromelain for heat and storage was improved after immobilization on nanoparticles. The Michaelis constant ( K m) of the immobilized enzyme was smaller than that of free enzyme, indicating that the immobilization could promote the stability of the enzyme and strengthen the affinity of the enzyme for the substrate.

Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: II. Heterotrophic conditions.

PubMed

Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

2012-10-10

The effect of the bacterium Azospirillum brasilense jointly immobilized with Chlorella vulgaris or C. sorokiniana in alginate beads on total carbohydrates and starch was studied under dark and heterotrophic conditions for 144 h in synthetic growth medium supplemented with either d-glucose or Na-acetate as carbon sources. In all treatments, enhanced total carbohydrates and starch content per culture and per cell was obtained after 24h; only jointly immobilized C. vulgaris growing on d-glucose significantly increased total carbohydrates and starch content after 96 h. Enhanced accumulation of carbohydrate and starch under jointly immobilized conditions was variable with time of sampling and substrate used. Similar results occurred when the microalgae was immobilized alone. In both microalgae growing on either carbon sources, the bacterium promoted accumulation of carbohydrates and starch; when the microalgae were immobilized alone, they used the carbon sources for cell multiplication. In jointly immobilized conditions with Chlorella spp., affinity to carbon source and volumetric productivity and yield were higher than when Chlorella spp. were immobilized alone; however, the growth rate was higher in microalgae immobilized alone. This study demonstrates that under heterotrophic conditions, A. brasilense promotes the accumulation of carbohydrates in two strains Chlorella spp. under certain time-substrate combinations, producing mainly starch. As such, this bacterium is a biological factor that can change the composition of compounds in microalgae in dark, heterotrophic conditions. Copyright © 2012. Published by Elsevier Inc.

pH-dependent immobilization of urease on glutathione-capped gold nanoparticles.

PubMed

Garg, Seema; De, Arnab; Mozumdar, Subho

2015-05-01

Urease is a nickel-dependent metalloenzyme that catalyzes the hydrolysis of urea to form ammonia and carbon dioxide. Although the enzyme serves a significant role in several detoxification and analytical processes, its usability is restricted due to high cost, availability in small amounts, instability, and a limited possibility of economic recovery from a reaction mixture. Hence, there is a need to develop an efficient, simple, and reliable immobilization strategy for the enzyme. In this study, the carboxyl terminated surface of glutathione-capped gold nanoparticles have been utilized as a solid support for the covalent attachment of urease. The immobilization has been carried out at different pH conditions so as to elucidate its effect on the immobilization efficiency and enzyme bioactivity. The binding of the enzyme has been quantitatively and qualitatively analyzed through techniques like ultraviolet-visible spectroscopy, intrinsic steady state fluorescence, and circular dichorism. The bioactivity of the immobilized enzyme was investigated with respect to the native enzyme under different thermal conditions. Recyclability and shelf life studies of the immobilized enzyme have also been carried out. Results reveal that the immobilization is most effective at pH of 7.4 followed by that in an acidic medium and is least in alkaline environment. The immobilized enzyme also exhibits enhance activity in comparison to the native form at physiological temperature. The immobilized urease (on gold glutathione nanoconjugates surface) can be effectively employed for biosensor fabrication, immunoassays and as an in vivo diagnostic tool in the future. © 2014 Wiley Periodicals, Inc.

Optimizing immobilized enzyme performance in cell-free environments to produce liquid fuels.

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

Kumar, Sanat

The overall goal of this project was to optimize enzyme performance for the production of bio-diesel fuel. Enzyme immobilization has attracted much attention as a means to increase productivity. Mesorporous silica materials have been known to be best suited for immobilizing enzymes. A major challenge is to ensure that the enzymatic activity is retained after immobilization. Two major factors which drive enzymatic deactivation are protein-surface and inter-protein interactions. Previously, we studied protein stability inside pores and how to optimize protein-surface interactions to minimize protein denaturation. In this work we studied eh effect of surface curvature and chemistry on inter-protein interactions.more » Our goal was to find suitable immobilization supports which minimize these inter-protein interactions. Our studies carried out in the frame work of Hydrophobic-Polar (HP) model showed that enzymes immobilized inside hydrophobic pores of optimal sizes are best suited to minimize these inter-protein interactions. Besides, this study is also of biological importance to understand the role of chaperonins in protein disaggregation. Both of these aspects profited immensely with collaborations with our experimental colleague, Prof. Georges Belfort (RPI), who performed the experimental analog of our theoretical works.« less

Heavy metal removal by caustic-treated yeast immobilized in alginate

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

Lu, Y.; Wilkins, E.

1995-12-31

Saccharomyces cerevisiae yeast biomass was treated with hot alkali to increase its biosorption capacity for heavy metals and then was immobilized in alginate gel. Biosorption capacities for Cu{sup 2+}, Cd{sup 2+}, and Zn{sup 2+} on alginate gel, native yeast, native yeast immobilized in alginate gel, and caustic-treated yeast immobilized in alginate gel were all compared. Immobilized yeasts could be reactivated and reused in a manner similar to the ion exchange resins. Immobilized caustic-treated yeast has high heavy metal biosorption capacity and high metal removal efficiency in a rather wide acidic pH region. The biosorption isotherm of immobilized caustic-treated yeast wasmore » studied, and empirical equations were obtained. The initial pH of polluted water affected the metal removal efficiency significantly, and the equilibrium biosorption capacity seemed to be temperature independent at lower initial metal concentrations.« less

Recovery time course in contractile function of fast and slow skeletal muscle after hindlimb immobilization

NASA Technical Reports Server (NTRS)

Witzmann, F. A.; Kim, D. H.; Fitts, R. H.

1982-01-01

The present study was undertaken to characterize the time course and extent of recovery in the isometric and isotonic contractile properties of fast and slow skeletal muscle following 6 wk of hindlimb immobilization. Female Sprague-Dawley rats were randomly assigned to an immobilized group or a control group. The results of the study show that fast and slow skeletal muscles possess the ability to completely recover normal contractile function following 6 wk of hindlimb immobilization. The rate of recovery is dependent on the fiber type composition of the affected muscle.

Effect of heparin and alendronate coating on titanium surfaces on inhibition of osteoclast and enhancement of osteoblast function

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

Moon, Ho-Jin; Yun, Young-Pil; Han, Choong-Wan

2011-09-23

Highlights: {yields} We examine bone metabolism of engineered alendronate attached to Ti surfaces. {yields} Alendronate-immobilized Ti enhances activation of osteoblast differentiation. {yields} Alendronate-immobilized Ti inhibits osteoclast differentiation. {yields} Alendronate-immobilized Ti may be a bioactive implant with dual functions. -- Abstract: The failure of orthopedic and dental implants has been attributed mainly to loosening of the implant from host bone, which may be due to weak bonding of the implant material to bone tissue. Titanium (Ti) is used in the field of orthopedic and dental implants because of its excellent biocompatibility and outstanding mechanical properties. Therefore, in the field of materialsmore » science and tissue engineering, there has been extensive research to immobilize bioactive molecules on the surface of implant materials in order to provide the implants with improved adhesion to the host bone tissue. In this study, chemically active functional groups were introduced on the surface of Ti by a grafting reaction with heparin and then the Ti was functionalized by immobilizing alendronate onto the heparin-grafted surface. In the MC3T3-E1 cell osteogenic differentiation study, the alendronate-immobilized Ti substrates significantly enhanced alkaline phosphatase activity (ALP) and calcium content. Additionally, nuclear factor kappa B ligand (RANKL)-induced osteoclast differentiation of RAW264.7 cells was inhibited with the alendronate-immobilized Ti as confirmed by TRAP analysis. Real time PCR analysis showed that mRNA expressions of osteocalcin and osteopontin, which are markers for osteogenesis, were upregulated in MC3T3-E1 cells cultured on alendronate-immobilized Ti. The mRNA expressions of TRAP and Cathepsin K, markers for osteoclastogenesis, in RAW264.7 cells cultured on alendronate-immobilized Ti were down-regulated. Our study suggests that alendronate-immobilized Ti may be a bioactive implant with dual functions to enhance osteoblast differentiation and to inhibit osteoclast differentiation simultaneously.« less

Improvement of the stability and activity of immobilized glucose oxidase on modified iron oxide magnetic nanoparticles

NASA Astrophysics Data System (ADS)

Abbasi, Mahboube; Amiri, Razieh; Bordbar, Abdol-Kalegh; Ranjbakhsh, Elnaz; Khosropour, Ahmad-Reza

2016-02-01

Immobilized proteins and enzymes are widely investigated in the medical field as well as the food and environmental fields. In this study, glucose oxidase (GOX) was covalently immobilized on the surface of modified iron oxide magnetic nanoparticles (MIMNs) to produce a bioconjugate complex. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) were used to the size, shape and structure characterization of the MIMNs. Binding of GOX to these MIMNs was confirmed by using FT-IR spectroscopy. The stability of the immobilized and free enzyme at different temperature and pH values was investigated by measuring the enzymatic activity. These studies reveal that the enzyme's stability is enhanced by immobilization. Further experiments showed that the storage stability of the enzyme is improved upon binding to the MIMNs. The results of kinetic measurements suggest that the effect of the immobilization process on substrate and product diffusion is small. Such bioconjugates can be considered as a catalytic nanodevice for accelerating the glucose oxidation reaction for biotechnological purposes.

Protein Immobilization Capabilities of Sucrose and Trehalose Glasses: The Effect of Protein/Sugar Concentration Unraveled by High-Field EPR.

PubMed

Malferrari, Marco; Savitsky, Anton; Lubitz, Wolfgang; Möbius, Klaus; Venturoli, Giovanni

2016-12-01

Disaccharide glasses are increasingly used to immobilize proteins at room temperature for structural/functional studies and long-term preservation. To unravel the molecular basis of protein immobilization, we studied the effect of sugar/protein concentration ratios in trehalose or sucrose matrixes, in which the bacterial photosynthetic reaction center (RC) was embedded as a model protein. The structural, dynamical, and H-bonding characteristics of the sugar-protein systems were probed by high-field W-band EPR of a matrix-dissolved nitroxide radical. We discovered that RC immobilization and thermal stabilization, being independent of the protein concentration in trehalose, occur in sucrose only at sufficiently low sugar/protein ratios. EPR reveals that only under such conditions does sucrose form a microscopically homogeneous matrix that immobilizes, via H-bonds, the nitroxide probe. We conclude that the protein immobilization capability depends critically on the propensity of the glass-forming sugar to create intermolecular H-bond networks, thus establishing long-range, homogeneous connectivity within the matrix.

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.

Immobilization of Pseudomonas sp. DG17 onto sodium alginate–attapulgite–calcium carbonate

PubMed Central

Wang, Hong Qi; Hua, Fei; Zhao, Yi Cun; Li, Yi; Wang, Xuan

2014-01-01

A strain of Pseudomonas sp. DG17, capable of degrading crude oil, was immobilized in sodium alginate–attapulgite–calcium carbonate for biodegradation of crude oil contaminated soil. In this work, proportion of independent variables, the laboratory immobilization parameters, the micromorphology and internal structure of the immobilized granule, as well as the crude oil biodegradation by sodium alginate–attapulgite–calcium carbonate immobilized cells and sodium alginate–attapulgite immobilized cells were studied to build the optimal immobilization carrier and granule-forming method. The results showed that the optimal concentrations of sodium alginate–attapulgite–calcium carbonate and calcium chloride were 2.5%–3.5%, 0.5%–1%, 3%–7% and 2%–4%, respectively. Meanwhile, the optimal bath temperature, embedding cell amount, reaction time and multiplication time were 50–60 °C, 2%, 18 h and 48 h, respectively. Moreover, biodegradation was enhanced by immobilized cells with a total petroleum hydrocarbon removal ranging from 33.56% ± 3.84% to 56.82% ± 3.26% after 20 days. The SEM results indicated that adding calcium carbonate was helpful to form internal honeycomb-like pores in the immobilized granules. PMID:26019567

Immobilization patterns and dynamics of acetate-utilizing methanogens immobilized in sterile granular sludge in upflow anaerobic sludge blanket reactors.

PubMed

Schmidt, J E; Ahring, B K

1999-03-01

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fed upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing M. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only M. mazeii S-6 immobilized, while the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (Ks and mumax) of immobilized M. concilii GP-6 or M. mazeii S-6 compared with suspended cultures, indicating that immobilization does not affect the growth kinetics of these methanogens. An enzyme-linked immunosorbent assay using polyclonal antibodies against either M. concilii GP-6 or M. mazeii S-6 showed significant variations in the two methanogenic populations in the different reactors. Polyclonal antibodies were further used to study the spatial distribution of the two methanogens. M. concilii GP-6 was immobilized only on existing support material without any specific pattern. M. mazeii S-6, however, showed a different immobilization pattern: large clumps were formed when the concentration of acetate was high, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps. The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor.

Immobilization of Thermomyces lanuginosus lipase on multi-walled carbon nanotubes and its application in the hydrolysis of fish oil

NASA Astrophysics Data System (ADS)

Matuoog, Naeema; Li, Kai; Yan, Yunjun

2017-12-01

In this study, lipase from Thermomyces lanuginosus (TLL) was immobilized on carbon nanotubes (MWCNTs) by physical adsorption, and the immobilizing conditions were optimized for maximum activity. The effects of enzyme loading, pH, temperature and time on the immobilization efficiency and specific activity were evaluated. The highest enzyme activity and immobilization efficiency of 90.66% and 110.5%, respectively, were achieved when the immobilized pH was 8, and a high rate of recovery activity of 111.3% occurred at 45 °C with 30-60 min providing a good result. When the immobilization efficiency was 95.8%, the recovery activity was 112.4%. The immobilization time had little effect on the immobilization efficiency, and 6 mg g-1 of lipase provided the highest immobilization efficiency of 97.78% and recovery activity of 112.8%. When the immobilized lipase was utilized to enrich docosahexaenoic acid (DHA) from fish oil, the DHA content increased with increasing amount of lipase up to 9 mg g-1. The water content had a clear effect when of 50% water was used at 45 °C and at a pH of 7 after 10 h. The DHA contents were 4.2-fold and 2.5-fold greater than the initial content of DHA fish oil for TLL-MWCNTs and free lipase, respectively. The degrees of hydrolysis after 6 cycles of successive use were over 80% and 62% for the immobilized TLL and free TLL, respectively, indicating the system recyclability and the ease of use of the immobilized TLL in industrial applications, especially in the fields of food and medicine.

Immobilization Patterns and Dynamics of Acetate-Utilizing Methanogens Immobilized in Sterile Granular Sludge in Upflow Anaerobic Sludge Blanket Reactors

PubMed Central

Schmidt, Jens Ejbye; Ahring, Birgitte Kjær

1999-01-01

Sterile granular sludge was inoculated with either Methanosarcina mazeii S-6, Methanosaeta concilii GP-6, or both species in acetate-fed upflow anaerobic sludge blanket (UASB) reactors to investigate the immobilization patterns and dynamics of aceticlastic methanogens in granular sludge. After several months of reactor operation, the methanogens were immobilized, either separately or together. The fastest immobilization was observed in the reactor containing M. mazeii S-6. The highest effluent concentration of acetate was observed in the reactor with only M. mazeii S-6 immobilized, while the lowest effluent concentration of acetate was observed in the reactor where both types of methanogens were immobilized together. No changes were observed in the kinetic parameters (Ks and μmax) of immobilized M. concilii GP-6 or M. mazeii S-6 compared with suspended cultures, indicating that immobilization does not affect the growth kinetics of these methanogens. An enzyme-linked immunosorbent assay using polyclonal antibodies against either M. concilii GP-6 or M. mazeii S-6 showed significant variations in the two methanogenic populations in the different reactors. Polyclonal antibodies were further used to study the spatial distribution of the two methanogens. M. concilii GP-6 was immobilized only on existing support material without any specific pattern. M. mazeii S-6, however, showed a different immobilization pattern: large clumps were formed when the concentration of acetate was high, but where the acetate concentration was low this strain was immobilized on support material as single cells or small clumps. The data clearly show that the two aceticlastic methanogens immobilize differently in UASB systems, depending on the conditions found throughout the UASB reactor. PMID:10049862

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.

Study of the effect of common infusions on glass ionomers using the PIXE and RBS techniques

NASA Astrophysics Data System (ADS)

Verón, María Gisela; Pérez, Pablo Daniel; Suárez, Sergio Gabriel; Prado, Miguel Oscar

2017-12-01

The effect of four commonly consumed beverages as mineral water, coffee, tea and mate tea on the elemental composition of a commercial glass ionomer was studied using Particle Induced X-ray Emission (PIXE) and Rutherford backscattering (RBS) techniques. We found that after immersion in acidic media, some elements as Al, Si and Na are lost from the glass-ionomer whereas others heavier, as K, Ca and La, increase their concentration at the surface. Although the concentration profiles of Al and Si are different in different media, in all of them the Al:Si ratio was close to unity and remained constant for different periods of immersion in all media. The incorporation of K, Mg and Fe to the surface is found for common infusions while for mineral water the glass-ionomer mainly loses F and Na.The RBS technique showed that immersion in different media produced a modification of the density of the glass ionomer surface layer due to the increment of the concentration of heavier elements at the surface. The thickness of the modified surface layer extends up to 3 μm when the immersion time is seven days and more than 6 μm after 33 days of immersion.

Utilization of spent coffee grounds for isolation and stabilization of Paenibacillus chitinolyticus CKS1 cellulase by immobilization.

PubMed

Buntić, Aneta V; Pavlović, Marija D; Antonović, Dušan G; Šiler-Marinković, Slavica S; Dimitrijević-Branković, Suzana I

2016-08-01

This study has explored the feasibility of using spent coffee grounds as a good supporting material for the Paenibacillus chitinolyticus CKS1 cellulase immobilization. An optimal operational conditions in a batch-adsorption system were found to be: carrier mass of 12 g/L, under the temperature of 45 °C and no pH adjustments. The immobilization yield reached about 71%. An equilibrium establishment between the cellulase and the carrier surface occurred within 45 min, whereas the process kinetics may be predicted by the pseudo-second-order model. An immobilized cellulase preparation expressed very good avicelase activity, this reached up to 2.67 U/g, and revealed an improved storage stability property, compared to free enzyme sample counterpart. The addition of metal ions, such as K(+) and Mg(2+) did not affect positively immobilization yield results, but on the contrary, contributed to an improved bio-activities of the immobilized cellulase, thus may be employed before each enzyme application. The method developed in this study offers a cheap and effective alternative for immediate enzyme isolation from the production medium and its stabilization, compared to other carriers used for the immobilization.

Cortical Reorganization after Hand Immobilization: The beta qEEG Spectral Coherence Evidences

PubMed Central

Fortuna, Marina; Teixeira, Silmar; Machado, Sérgio; Velasques, Bruna; Bittencourt, Juliana; Peressutti, Caroline; Budde, Henning; Cagy, Mauricio; Nardi, Antonio E.; Piedade, Roberto; Ribeiro, Pedro; Arias-Carrión, Oscar

2013-01-01

There is increasing evidence that hand immobilization is associated with various changes in the brain. Indeed, beta band coherence is strongly related to motor act and sensitive stimuli. In this study we investigate the electrophysiological and cortical changes that occur when subjects are submitted to hand immobilization. We hypothesized that beta coherence oscillations act as a mechanism underlying inter- and intra-hemispheric changes. As a methodology for our study fifteen healthy individuals between the ages of 20 and 30 years were subjected to a right index finger task before and after hand immobilization while their brain activity pattern was recorded using quantitative electroencephalography. This analysis revealed that hand immobilization caused changes in frontal, central and parietal areas of the brain. The main findings showed a lower beta-2 band in frontal regions and greater cortical activity in central and parietal areas. In summary, the coherence increased in the frontal, central and parietal cortex, due to hand immobilization and it adjusted the brains functioning, which had been disrupted by the procedure. Moreover, the brain adaptation upon hand immobilization of the subjects involved inter- and intra-hemispheric changes. PMID:24278213

Optimization of pectinase immobilization on grafted alginate-agar gel beads by 24 full factorial CCD and thermodynamic profiling for evaluating of operational covalent immobilization.

PubMed

Abdel Wahab, Walaa A; Karam, Eman A; Hassan, Mohamed E; Kansoh, Amany L; Esawy, Mona A; Awad, Ghada E A

2018-07-01

Pectinase produced by a honey derived from the fungus Aspergillus awamori KX943614 was covalently immobilized onto gel beads made of alginate and agar. Polyethyleneimine, glutaraldehyde, loading time and enzyme's units were optimized by 2 4 full factorial central composite design (CCD). The immobilization process increased the optimal working pH for the free pectinase from 5 to a broader range of pH4.5-5.5 and the optimum operational temperature from 55°C to a higher temperature, of 60°C, which is favored to reduce the enzyme's microbial contamination. The thermodynamics studies showed a thermal stability enhancement against high temperature for the immobilized formula. Moreover, an increase in half-lives and D-values was achieved. The thermodynamic studies proved that immobilization of pectinase made a remarkable increase in enthalpy and free energy because of enzyme stability enhancement. The reusability test revealed that 60% of pectinase's original activity was retained after 8 successive cycles. This gel formula may be convenient for immobilization of other industrial enzymes. Copyright © 2018 Elsevier B.V. All rights reserved.

Biodegradation and kinetic study of benzene in bioreactor packed with PUF and alginate beads and immobilized with Bacillus sp. M3.

PubMed

Kureel, M K; Geed, S R; Giri, B S; Rai, B N; Singh, R S

2017-10-01

Benzene removal in free and immobilized cells on polyurethane foam (PUF) and polyvinyl alcohol (PVA)-alginate beads was studied using an indigenous soil bacterium Bacillus sp. M3 isolated from petroleum-contaminated soil. The important process parameters (pH, temperature and inoculums size) were optimized and found to be 7, 37°C and 6.0×10 8 CFU/mL, respectively. Benzene removals were observed to be 70, 84 and 90% within 9days in a free cell, immobilized PVA-alginate beads and PUF, respectively under optimum operating conditions. FT-IR and GC-MS analysis confirm the presence of phenol, 1,2-benzenediol, hydroquinone and benzoate as metabolites. The important kinetic parameter ratios (µ max /K s ; L/mg·day ) calculated using Monod model was found to be 0.00123 for free cell, 0.00159 for immobilized alginate beads and 0.002016 for immobilized PUF. Similarly inhibition constants (K i ; mg/L) calculated using Andrew-Haldane model was found to be 435.84 for free cell, 664.25 for immobilized alginate beads and 724.93 for immobilized PUF. Copyright © 2017 Elsevier Ltd. All rights reserved.

Useful oriented immobilization of antibodies on chimeric magnetic particles: direct correlation of biomacromolecule orientation with biological activity by AFM studies.

PubMed

Marciello, Marzia; Filice, Marco; Olea, David; Velez, Marisela; Guisan, José M; Mateo, Cesar

2014-12-16

The preparation and performance of a suitable chimeric biosensor based on antibodies (Abs) immobilized on lipase-coated magnetic particles by means of a standing orienting strategy are presented. This novel system is based on hydrophobic magnetic particles coated with modified lipase molecules able to orient and further immobilize different Abs in a covalent way without any previous site-selective chemical modification of biomacromolecules. Different key parameters attending the process were studied and optimized. The optimal preparation was performed using a controlled loading (1 nmol Ab g(-1) chimeric support) at pH 9 and a short reaction time to recover a biological activity of about 80%. AFM microscopy was used to study and confirm the Abs-oriented immobilization on lipase-coated magnetic particles and the final achievement of a highly active and recyclable chimeric immune sensor. This direct technique was demonstrated to be a powerful alternative to the indirect immunoactivity assay methods for the study of biomacromolecule-oriented immobilizations.

A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer

PubMed Central

Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

2015-01-01

Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10−4 to 102 ng/mL). PMID:26007739

A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer.

PubMed

Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

2015-05-22

Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10(-4) to 10(2) ng/mL).

Fabrication of anticoagulation layer on titanium surface by sequential immobilization of poly (ethylene glycol) and albumin.

PubMed

Pan, Chang-Jiang; Hou, Yan-Hua; Zhang, Bin-Bin; Zhang, Lin-Cai

2014-01-01

This paper presents a simple method to sequentially immobilize poly (ethylene glycol) (PEG) and albumin on titanium surface to enhance the blood compatibility. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) analysis indicated that PEG and albumin were successfully immobilized on the titanium surface. Water contact angle results showed a better hydrophilic surface after the immobilization. The immobilized PEG or albumin can not only obviously prevent platelet adhesion and activation but also prolong activated partial thromboplastin time (APTT), leading to the improved anticoagulation. Moreover, immobilization of albumin on PEG-modified surface can further improve the anticoagulation. The approach in the present study provides an effective and efficient method to improve the anticoagulation of blood-contact biomedical devices such as coronary stents.

Immobilization of Streptomyces thermotolerans 11432 on polyurethane foam to improve production of acetylisovaleryltylosin.

PubMed

Zhu, Hongji; Wang, Weihua; Liu, Jiaheng; Caiyin, Qinggele; Qiao, Jianjun

2015-01-01

In this study, polyurethane foam (PUF) was chemically treated to immobilize Streptomyces thermotolerans 11432 for semi-continuous production of acetylisovaleryltylosin (AIV). Based on experimental results, positive cross-linked PUF (PCPUF) was selected as the most effective carrier according to immobilized cell mass. The effect of adsorption time on immobilized mass was investigated. AIV concentration (33.54 mg/l) in batch fermentations with immobilized cells was higher than with free cells (20.34 mg/l). In repeated batch fermentations with immobilized S. thermotolerans 11432 using PCPUF cubes, high AIV concentrations and conversion rates were attained, ranging from 25.56 to 34.37 mg/l and 79.93 to 86.31 %, respectively. Significantly, this method provides a feasible strategy for efficient AIV production and offers the potential for large-scale production.

Exercise following a short immobilization period is detrimental to tendon properties and joint mechanics in a rat rotator cuff injury model.

PubMed

Peltz, Cathryn D; Sarver, Joseph J; Dourte, Leann M; Würgler-Hauri, Carola C; Williams, Gerald R; Soslowsky, Louis J

2010-07-01

Rotator cuff tears are a common clinical problem that can result in pain and disability. Previous studies in a rat model showed enhanced tendon to bone healing with postoperative immobilization. The objective of this study was to determine the effect of postimmobilization activity level on insertion site properties and joint mechanics in a rat model. Our hypothesis was that exercise following a short period of immobilization will cause detrimental changes in insertion site properties compared to cage activity following the same period of immobilization, but that passive shoulder mechanics will not be affected. We detached and repaired the supraspinatus tendon of 22 Sprague-Dawley rats, and the injured shoulder was immobilized postoperatively for 2 weeks. Following immobilization, rats were prescribed cage activity or exercise for 12 weeks. Passive shoulder mechanics were determined, and following euthanasia, tendon cross-sectional area and mechanical properties were measured. Exercise following immobilization resulted in significant decreases compared to cage activity in range of motion, tendon stiffness, modulus, percent relaxation, and several parameters from both a structurally based elastic model and a quasi-linear viscoelastic model. Therefore, we conclude that after a short period of immobilization, increased activity is detrimental to both tendon mechanical properties and shoulder joint mechanics, presumably due to increased scar production. (c) 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc

Effect of hydrogel elasticity and ephrinB2-immobilized manner on Runx2 expression of human mesenchymal stem cells.

PubMed

Toda, Hiroyuki; Yamamoto, Masaya; Uyama, Hiroshi; Tabata, Yasuhiko

2017-08-01

The objective of this study is to design the manner of ephrinB2 immobilized onto polyacrylamide (PAAm) hydrogels with varied elasticity and evaluate the effect of hydrogels elasticity and the immobilized manner of ephrinB2 on the Runx2 expression of human mesenchymal stem cells (hMSC). The PAAm hydrogels were prepared by the radical polymerization of acrylamide (AAm), and N,N'-methylenebisacrylamide (BIS). By changing the BIS concentration, the elasticity of PAAm hydrogels changed from 1 to 70kPa. For the bio-specific immobilization of ephrinB2, a chimeric protein of ephrinB2 and Fc domain was immobilized onto protein A-conjugated PAAm hydrogels by making use of the bio-specific interaction between the Fc domain and protein A. When hMSC were cultured on the ephrinB2-immobilized PAAm hydrogels with varied elasticity, the morphology of hMSC was of cuboidal shape on the PAAm hydrogels immobilized with ephrinB2 compared with non-conjugated ones, irrespective of the hydrogels elasticity. The bio-specific immobilization of ephrinB2 enhanced the level of Runx2 expression. The expression level was significantly high for the hydrogels of 3.6 and 5.9kPa elasticity with bio-specific immobilization of ephrinB2 compared with other hydrogels with the same elasticity. The hydrogels showed a significantly down-regulated RhoA activity. It is concluded that the Runx2 expression of hMSC is synergistically influenced by the hydrogels elasticity and their immobilized manner of ephrinB2 immobilized. Differentiation fate of mesenchymal stem cells (MSC) is modified by biochemical and biophysical factors, such as elasticity and signal proteins. However, there are few experiments about combinations of them. In this study, to evaluate the synergistic effect of them on cell properties of MSC, we established to design the manner of Eph signal ligand, ephrinB2, immobilized onto polyacrylamide hydrogels with varied elasticity. The gene expression level of an osteogenic maker, Runx2, was enhanced by the immobilized manner, and significantly enhanced for the hydrogels of around 4kPa elasticity with bio-specific immobilization of ephrinB2. This is the novel report describing to demonstrate that the Runx2 expression of MSC is synergistically influenced by the hydrogels elasticity and their manner of ephrinB2 immobilized. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Cascade catalysis in membranes with enzyme immobilization for multi-enzymatic conversion of CO2 to methanol.

PubMed

Luo, Jianquan; Meyer, Anne S; Mateiu, R V; Pinelo, Manuel

2015-05-25

Facile co-immobilization of enzymes is highly desirable for bioconversion methods involving multi-enzymatic cascade reactions. Here we show for the first time that three enzymes can be immobilized in flat-sheet polymeric membranes simultaneously or separately by simple pressure-driven filtration (i.e. by directing membrane fouling formation), without any addition of organic solvent. Such co-immobilization and sequential immobilization systems were examined for the production of methanol from CO2 with formate dehydrogenase (FDH), formaldehyde dehydrogenase (FaldDH) and alcohol dehydrogenase (ADH). Enzyme activity was fully retained by this non-covalent immobilization strategy. The two immobilization systems had similar catalytic efficiencies because the second reaction (formic acid→formaldehyde) catalyzed by FaldDH was found to be the cascade bottleneck (a threshold substrate concentration was required). Moreover, the trade-off between the mitigation of product inhibition and low substrate concentration for the adjacent enzymes probably made the co-immobilization meaningless. Thus, sequential immobilization could be used for multi-enzymatic cascade reactions, as it allowed the operational conditions for each single step to be optimized, not only during the enzyme immobilization but also during the reaction process, and the pressure-driven mass transfer (flow-through mode) could overcome the diffusion resistance between enzymes. This study not only offers a green and facile immobilization method for multi-enzymatic cascade systems, but also reveals the reaction bottleneck and provides possible solutions for the bioconversion of CO2 to methanol. Copyright © 2015 Elsevier B.V. All rights reserved.

Surface functionalization of chitosan-coated magnetic nanoparticles for covalent immobilization of yeast alcohol dehydrogenase from Saccharomyces cerevisiae

NASA Astrophysics Data System (ADS)

Li, Gui-yin; Zhou, Zhi-de; Li, Yuan-jian; Huang, Ke-long; Zhong, Ming

2010-12-01

A novel and efficient immobilization of yeast alcohol dehydrogenase (YADH, EC1.1.1.1) from Saccharomyces cerevisiae has been developed by using the surface functionalization of chitosan-coated magnetic nanoparticles (Fe 3O 4/KCTS) as support. The magnetic Fe 3O 4/KCTS nanoparticles were prepared by binding chitosan alpha-ketoglutaric acid (KCTS) onto the surface of magnetic Fe 3O 4 nanoparticles. Later, covalent immobilization of YADH was attempted onto the Fe 3O 4/KCTS nanoparticles. The effect of various preparation conditions on the immobilized YADH process such as immobilization time, enzyme concentration and pH was investigated. The influence of pH and temperature on the activity of the free and immobilized YADH using phenylglyoxylic acid as substrate has also been studied. The optimum reaction temperature and pH value for the enzymatic conversion catalyzed by the immobilized YADH were 30 °C and 7.4, respectively. Compared to the free enzyme, the immobilized YADH retained 65% of its original activity and exhibited significant thermal stability and good durability.

Immobilization of microbial cell and yeast cell and its application to biomass conversion using radiation techniques

NASA Astrophysics Data System (ADS)

Kaetsu, Isao; Kumakura, Minoru; Fujimura, Takashi; Kasai, Noboru; Tamada, Masao

The recent results of immobilization of cellulase-producing cells and ethanol-fermentation yeast by radiation were reported. The enzyme of cellulase produced by immobilized cells was used for saccharification of lignocellulosic wastes and immobilized yeast cells were used for fermentation reaction from glucose to ethanol. The wastes such as chaff and bagasse were treated by γ-ray or electron-beam irradiation in the presence of alkali and subsequent mechanical crushing, to form a fine powder less than 50 μm in diameter. On the other hand, Trichoderma reesei as a cellulase-producing microbial cell was immobilized on a fibrous carrier having a specific porous structure and cultured to produce cellulase. The enzymatic saccharification of the pretreated waste was carried out using the produced cellulase. The enhanced fermentation process to produce ethanol from glucose with the immobilized yeast by radiation was also studied. The ethanol productivity of immobilized growing yeast cells thus obtained was thirteen times that of free yeast cells in a 1:1 volume of liquid medium to immobilized yeast cells.

Production of tannase by the immobilized cells of Bacillus licheniformis KBR6 in Ca-alginate beads.

PubMed

Mohapatra, P K D; Mondal, K C; Pati, B R

2007-06-01

The present study was aimed at finding the optimal conditions for immobilization of Bacillus licheniformis KBR6 cells in calcium-alginate (Ca-alginate) beads and determining the operational stability during the production of tannin-acyl-hydrolase (tannase) under semicontinous cultivation. The active cells of B. licheniformis KBR6 were immobilized in Ca-alginate and used for the production of tannase. The influence of alginate concentration (5, 10, 20 and 30 g l(-1)) and initial cell loading on enzyme production were studied. The production of tannase increased significantly with increasing alginate concentration and reached a maximum enzyme yield of 0.56 +/- 0.03 U ml(-1) at 20 g l(-1). This was about 1.70-fold higher than that obtained by free cells. The immobilized cells produced tannase consistently over 13 repeated cycles and reached a maximum level at the third cycle. Scanning electron microscope study indicated that the cells in Ca-alginate beads remain in normal shape. The Ca-alginate entrapment is a promising immobilization method of B. licheniformis KBR6 for repeated tannase production. Tannase production by immobilized cells is superior to that of free cells because it leads to higher volumetric activities within the same period of fermentation. This is the first report of tannase production from immobilized bacterial cells. The bacterium under study can produce higher amounts of tannase with respect to other fungal strains within a short cultivation period.

Does immobilization after arthroscopic rotator cuff repair increase tendon healing? A systematic review and meta-analysis.

PubMed

Shen, Chong; Tang, Zhi-Hong; Hu, Jun-Zu; Zou, Guo-Yao; Xiao, Rong-Chi; Yan, Dong-Xue

2014-09-01

To determine whether immobilization after arthroscopic rotator cuff repair improved tendon healing compared with early passive motion. A systematic electronic literature search was conducted to identify randomized controlled trials (RCTs) comparing early passive motion with immobilization after arthroscopic rotator cuff repair. The primary outcome assessed was tendon healing in the repaired cuff. Secondary outcome measures were range of motion (ROM) and American Shoulder and Elbow Surgeons (ASES) shoulder scale, Simple Shoulder Test (SST), Constant, and visual analog scale (VAS) for pain scores. Pooled analyses were performed using a random effects model to obtain summary estimates of treatment effect with 95% confidence intervals. Heterogeneity among included studies was quantified. Three RCTs examining 265 patients were included. Meta-analysis revealed no significant difference in tendon healing in the repaired cuff between the early-motion and immobilization groups. A significant difference in external rotation at 6 months postoperatively favored early motion over immobilization, but no significant difference was observed at 1 year postoperatively. In one study, Constant scores were slightly higher in the early-motion group than in the immobilization group. Two studies found no significant difference in ASES, SST, or VAS score between groups. We found no evidence that immobilization after arthroscopic rotator cuff repair was superior to early-motion rehabilitation in terms of tendon healing or clinical outcome. Patients in the early-motion group may recover ROM more rapidly. Level II; systematic review of levels I and II studies.

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.

The HRSC Experiment on Mars Express: First Imaging Results from the Commissioning Phase

NASA Astrophysics Data System (ADS)

Oberst, J.; Neukum, G.; Hoffmann, H.; Jaumann, R.; Hauber, E.; Albertz, J.; McCord, T. B.; Markiewicz, W. J.

2004-12-01

The ESA Mars Express spacecraft was launched from Baikonur on June 2, 2003, entered Mars orbit on December 25, 2003, and reached the nominal mapping orbit on January 28, 2004. Observing conditions were favorable early on for the HRSC (High Resolution Stereo Camera), designed for the mapping of the Martian surface in 3-D. The HRSC is a pushbroom scanner with 9 CCD line detectors mounted in parallel and perpendicular to the direction of flight on the focal plane. The camera can obtain images at high resolution (10 m/pix), in triple stereo (20 m/pix), in four colors, and at five different phase angles near-simultaneously. An additional Super-Resolution Channel (SRC) yields nested-in images at 2.3 m/pix for detailed photogeologic studies. Even for nominal spacecraft trajectory and camera pointing data from the commissioning phase, solid stereo image reconstructions are feasible. More yet, the three-line stereo data allow us to identify and correct errors in navigation data. We find that > 99% of the stereo rays intersect within a sphere of radius < 20m after orbit and pointing data correction. From the HRSC images we have produced Digital Terrain Models (DTMs) with pixel sizes of 200 m, some of them better. HRSC stereo models and data obtained by the MOLA (Mars Orbiting Laser Altimeter) show good qualitative agreement. Differences in absolute elevations are within 50 m, but may reach several 100 m in lateral positioning (mostly in the spacecraft along-track direction). After correction of these offsets, the HRSC topographic data conveniently fill the gaps between the MOLA tracks and reveal hitherto unrecognized morphologic detail. At the time of writing, the HRSC has covered approx. 22.5 million square kilometers of the Martian surface. In addition, data from 5 Phobos flybys from May through August 2004 were obtained. The HRSC is beginning to make major contributions to geoscience, atmospheric science, photogrammetry, and cartography of Mars (papers submitted to Nature).

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.).

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.

Combined Non-invasive PIXE/PIGE Analyses of Mammoth Ivory from Aurignacian Archaeological Sites.

PubMed

Reiche, Ina; Heckel, Claire; Müller, Katharina; Jöris, Olaf; Matthies, Tim; Conard, Nicholas J; Floss, Harald; White, Randall

2018-06-18

Among the earliest Homo sapiens societies in Eurasia, the Aurignacian phase of the Early Upper Paleolithic, approximately 40 000-30 000 years ago, mammoth ivory assumed great social and economic significance, and was used to create hundreds of personal ornaments as well as the earliest known works of three-dimensional figurative art in the world. This paper reports on the results of micro-PIXE/PIGE analyses of mammoth-ivory artifacts and debris from five major sites of Aurignacian ivory use. Patterns of variable fluorine content indicate regionally distinctive strategies of ivory procurement that correspond to apparent differences in human-mammoth interactions. Preserved trace elements (Br, Sr, Zn) indicate that differences at the regional level are applicable to sourcing Paleolithic ivory at the regional scale. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Scanning-PIXE analysis of gold lace embroideries in a relic of St. Francis

NASA Astrophysics Data System (ADS)

Migliori, A.; Grassi, N.; Mandò, P. A.

2008-05-01

In this work, we describe the compositional analysis performed by scanning-mode PIXE on the metal threads of a XIII century embroidery. The precious work analysed is the pillow-case used to cover the pillow, on which - according to tradition - St. Francis of Assisi was resting his head when he died. Measurements were performed in order to characterise the embroideries of the two sides and the passementerie in the lateral hems. Several areas, each of the order of two square millimetres, were scanned with a 3 MeV proton external beam of 20 μm size on target, using the external micro-beam facility of our laboratory, with list-mode acquisition. Analysis of elemental maps and spectra from selected homogeneous sub-areas allowed us to extract the quantitative composition of the gilded tape and estimates of its thickness.

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.

An Apparatus For Student Projects Using External-Beam PIXE And PIGE

NASA Astrophysics Data System (ADS)

Correll, Francis D.; Edsall, Douglas W.; DePooter, Katherine A.; Maskell, Nicholas D.; Vanhoy, Jeffrey R.

2011-06-01

We recently installed a simple endstation at the Naval Academy Tandem Accelerator Laboratory to support student projects using external-beam PIXE and PIGE. It consists of a short, graphite-lined beamline extension with a thin window, an interlocked box that surrounds the target, detectors for x- and gamma rays, provision for flooding the target with helium gas, easily changed x-ray absorbers, and a compact video camera for monitoring the position of the beam spot. We used this system to measure the elemental composition of colonial-era architectural materials, principally bricks and mortar, from James Madison's Montpelier, the reconstructed Virginia estate of the fourth President of the United States. We describe the design and construction of the system, relate some of our experiences using it, and present some preliminary data from our investigations.

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.

SymPix: A Spherical Grid for Efficient Sampling of Rotationally Invariant Operators

NASA Astrophysics Data System (ADS)

Seljebotn, D. S.; Eriksen, H. K.

2016-02-01

We present SymPix, a special-purpose spherical grid optimized for efficiently sampling rotationally invariant linear operators. This grid is conceptually similar to the Gauss-Legendre (GL) grid, aligning sample points with iso-latitude rings located on Legendre polynomial zeros. Unlike the GL grid, however, the number of grid points per ring varies as a function of latitude, avoiding expensive oversampling near the poles and ensuring nearly equal sky area per grid point. The ratio between the number of grid points in two neighboring rings is required to be a low-order rational number (3, 2, 1, 4/3, 5/4, or 6/5) to maintain a high degree of symmetries. Our main motivation for this grid is to solve linear systems using multi-grid methods, and to construct efficient preconditioners through pixel-space sampling of the linear operator in question. As a benchmark and representative example, we compute a preconditioner for a linear system that involves the operator \\widehat{{\\boldsymbol{D}}}+{\\widehat{{\\boldsymbol{B}}}}T{{\\boldsymbol{N}}}-1\\widehat{{\\boldsymbol{B}}}, where \\widehat{{\\boldsymbol{B}}} and \\widehat{{\\boldsymbol{D}}} may be described as both local and rotationally invariant operators, and {\\boldsymbol{N}} is diagonal in the pixel domain. For a bandwidth limit of {{\\ell }}{max} = 3000, we find that our new SymPix implementation yields average speed-ups of 360 and 23 for {\\widehat{{\\boldsymbol{B}}}}T{{\\boldsymbol{N}}}-1\\widehat{{\\boldsymbol{B}}} and \\widehat{{\\boldsymbol{D}}}, respectively, compared with the previous state-of-the-art implementation.

Ultrasound-aided formation of gold nanoparticles on multi-walled carbon nanotubes functionalized with mercaptobenzene moieties.

PubMed

Park, Gle; Lee, Kyung G; Lee, Seok Jae; Park, Tae Jung; Wi, Ringbok; Wang, Kye Won; Kim, Do Hyun

2011-07-01

A hybrid of multi-walled carbon nanotube (MWCNT) and gold nanoparticle (Au NP) was prepared under ultrasound irradiation. The approach starts with the functionalization of the walls of MWCNTs with mercaptobenzene moieties for the subsequent immobilization of Au NPs. From the Raman spectra, mercaptobenzene was proven to exist on the MWCNTs. Gold ions were added to the aqueous dispersion of functionalized MWCNTs (f-MWCNTs), and were reduced with the aid of ultrasound and ammonium hydroxide. The reduced gold nanoparticles were examined from the TEM images. Au NPs adhered specifically on the thiol groups of mercaptobenzene to be deposited uniformly on the outer walls of the f-MWCNTs. The application of ultrasound led to a high yield of MWCNT-Au nanocomposites and to the dense distribution of the Au NPs. Moreover, the synthesis reaction rate of the hybrid was considerably enhanced relative to synthesis with mechanical agitation. Through an adsorption test using gold-binding-peptide-(GBP)-modified biomolecules, the hybrid's potential for biological diagnosis was verified.

An approach for liposome immobilization using sterically stabilized micelles (SSMs) as a precursor for bio-layer interferometry-based interaction studies.

PubMed

Wallner, Jakob; Lhota, Gabriele; Schosserer, Markus; Vorauer-Uhl, Karola

2017-06-01

Non-fluidic bio-layer interferometry (BLI) has rapidly become a standard tool for monitoring almost all biomolecular interactions in a label-free, real-time and high-throughput manner. High-efficiency screening methods which measure the kinetics of liposomes with a variety of compounds require the immobilization of liposomes. In this work, a method is described for immobilizing liposomes for interaction studies, based on the biophysical principles of this biosensor platform. The immobilization approach includes the loading of DSPE-PEG (2000) -biotin containing sterically stabilized micelles (SSMs) which are restructured in a buffer change step, resulting in an accessible substrate for liposome immobilization. Liposomes in a concentration of 5mM of varying composition and fluidity were immobilized on the sensor surface by inserting the hydrophobic residues of the former loaded SSMs. This proof of principle was carried out using Cytochrome C as a membrane-interacting model protein. The binding of Cytochrome C to the immobilized liposomes was demonstrated, and the derived kinetic and affinity constants were similar to values given in the literature. In order to obtain a detailed understanding of this surface, and to show the integrity of the liposomes, confocal fluorescence microscopy was used. Images of immobilized liposomes containing calcein in the aqueous core indicated intact vesicles. A combination of this simple liposome immobilization approach, the possibility of automation on BLI systems with high throughput within an acceptable timescale and excellent reproducibility makes this assay suitable for basic research as well as for industrial and regulatory applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of membranes with various hydrophobic/hydrophilic properties on lipase immobilized activity and stability.

PubMed

Chen, Guan-Jie; Kuo, Chia-Hung; Chen, Chih-I; Yu, Chung-Cheng; Shieh, Chwen-Jen; Liu, Yung-Chuan

2012-02-01

In this study, three membranes: regenerated cellulose (RC), glass fiber (GF) and polyvinylidene fluoride (PVDF), were grafted with 1,4-diaminobutane (DA) and activated with glutaraldehyde (GA) for lipase covalent immobilization. The efficiencies of lipases immobilized on these membranes with different hydrophobic/hydrophilic properties were compared. The lipase immobilized on hydrophobic PVDF-DA-GA membrane exhibited more than an 11-fold increase in activity compared to its immobilization on a hydrophilic RC-DA-GA membrane. The relationship between surface hydrophobicity and immobilized efficiencies was investigated using hydrophobic/hydrophilic GF membranes which were prepared by grafting a different ratio of n-butylamine/1,4-diaminobutane (BA/DA). The immobilized lipase activity on the GF membrane increased with the increased BA/DA ratio. This means that lipase activity was exhibited more on the hydrophobic surface. Moreover, the modified PVDF-DA membrane was grafted with GA, epichlorohydrin (EPI) and cyanuric chloride (CC), respectively. The lipase immobilized on the PVDF-DA-EPI membrane displayed the highest specific activity compared to other membranes. This immobilized lipase exhibited more significant stability on pH, thermal, reuse, and storage than did the free enzyme. The results exhibited that the EPI modified PVDF is a promising support for lipase immobilization. Copyright © 2011 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Covalent immobilization of Candida rugosa lipase on aldehyde functionalized hydrophobic support and the application for synthesis of oleic acid ester.

PubMed

Temoçin, Zülfikar

2013-01-01

This study focuses on Candida rugosa lipase (CRL) immobilization by covalent attachment on poly(ethylene terephthalate)-grafted glycidyl methacrylate (PET-g-GMA) fiber. The immobilization yielded a protein loading of 2.38 mg g(-1) of PET-g-GMA fiber. The performances of the immobilized and free CRLs were evaluated with regard to hydrolysis of olive oil and esterification of oleic acid. The optimum activity pH of the CRL was changed by immobilization to neutral range. The maximum activity of the free and immobilized CRLs occurred at 40 and 45 °C respectively. The immobilized lipase retained 65% of its original activity at 50 °C for 2 h. It was found that the immobilized lipase stored at 4 °C retained 90% of its original activity after 35 days, whereas the free lipase stored at 4 °C retained 69% of its original activity after the same period. In the esterification experiments, the immobilized CRL could maintain a high activity at a water content range from 1.5 to 6% (v/v), while the activity of free CRL showed a clear dependence on water content and decreased rapidly at above 3% (v/v) water content. In addition, after five reuses, the esterification percent yield of the immobilized CRL slightly decreased from 29 to 27%.

Trypsin inhibitor screening in traditional Chinese medicine by using an immobilized enzyme microreactor in capillary and molecular docking study.

PubMed

Cheng, Mengxia; Chen, Zilin

2017-08-01

A trypsin immobilized enzyme microreactor was successfully prepared in capillary for studying enzyme kinetics of trypsin and online screening of trypsin inhibitors from traditional Chinese medicine through capillary electrophoresis. Trypsin was immobilized on the inner wall at the inlet of the capillary treated with polydopamine. The rest of the capillary was used as a separation channel. The parameters including the separation efficiency and the activity of immobilized trypsin were comprehensively evaluated. Under the optimal conditions, online screening of trypsin inhibitors each time can be carried out within 6 min. The Michaelis-Menten constant of immobilized trypsin was calculated to be 0.50 mM, which indicated high affinity of the immobilized trypsin for the substrate. The half-maximal inhibitory concentration of known inhibitor of benzamidine hydrochloride hydrate as a model inhibitor was 13.32 mM. The proposed method was successfully applied to screen trypsin inhibitors from 15 compounds of traditional Chinese medicine. It has been found that baicalin showed inhibitory potency. Molecular docking study well supported the experimental result by exhibiting molecular interaction between enzyme and inhibitors. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Quantitative investigation of physical factors contributing to gold nanoparticle-mediated proton dose enhancement.

PubMed

Cho, Jongmin; Gonzalez-Lepera, Carlos; Manohar, Nivedh; Kerr, Matthew; Krishnan, Sunil; Cho, Sang Hyun

2016-03-21

Some investigators have shown tumor cell killing enhancement in vitro and tumor regression in mice associated with the loading of gold nanoparticles (GNPs) before proton treatments. Several Monte Carlo (MC) investigations have also demonstrated GNP-mediated proton dose enhancement. However, further studies need to be done to quantify the individual physical factors that contribute to the dose enhancement or cell-kill enhancement (or radiosensitization). Thus, the current study investigated the contributions of particle-induced x-ray emission (PIXE), particle-induced gamma-ray emission (PIGE), Auger and secondary electrons, and activation products towards the total dose enhancement. Specifically, GNP-mediated dose enhancement was measured using strips of radiochromic film that were inserted into vials of cylindrical GNPs, i.e. gold nanorods (GNRs), dispersed in a saline solution (0.3 mg of GNRs/g or 0.03% of GNRs by weight), as well as vials containing water only, before proton irradiation. MC simulations were also performed with the tool for particle simulation code using the film measurement setup. Additionally, a high-purity germanium detector system was used to measure the photon spectrum originating from activation products created from the interaction of protons and spherical GNPs present in a saline solution (20 mg of GNPs/g or 2% of GNPs by weight). The dose enhancement due to PIXE/PIGE recorded on the films in the GNR-loaded saline solution was less than the experimental uncertainty of the film dosimetry (<2%). MC simulations showed highly localized dose enhancement (up to a factor 17) in the immediate vicinity (<100 nm) of GNRs, compared with hypothetical water nanorods (WNRs), mostly due to GNR-originated Auger/secondary electrons; however, the average dose enhancement over the entire GNR-loaded vial was found to be minimal (0.1%). The dose enhancement due to the activation products from GNPs was minimal (<0.1%) as well. In conclusion, under the currently investigated conditions that are considered clinically relevant, PIXE, PIGE, and activation products contribute minimally to GNP/GNR-mediated proton dose enhancement, whereas Auger/secondary electrons contribute significantly but only at short distances (<100 nm) from GNPs/GNRs.

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.

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.

Application of PIXE to study ancient Iranian silver coins

NASA Astrophysics Data System (ADS)

Hajivaliei, M.; Mohammadifar, Y.; Ghiyasi, K.; Jaleh, B.; Lamehi-Rachti, M.; Oliaiy, P.

2008-04-01

A number of ancient Iranian silver coins belonging to Khosrau II (592-626 A.D.) minted during Sasanians dynasty were analyzed using proton induced X-ray emission (PIXE) technique. The 2 MeV proton beam with a current of 2-3 nA from AEOI, Van de Graaff accelerator was used to bombard the coins. The characteristic X-rays emitted from the samples, were detected by a Si(Li) detector from ORTEC with an energy resolution of 170 eV at 5.9 keV. The detector was placed in the beam direction at 135°. The elements Cl, Ca, Ti, Mn, Fe, Cu, Au and Pb were observed in the coins along with the major component silver. The percentage of silver varied between 85.87 and 93.39%. The possible correlation between the composition of coins and the minting time or the minting location of coins was the prime goal. There was a negative correlation between copper and silver. The weight of coins varied between 4.02 and 4.30 g. Going through the results, it seems that the local mines were used to die-strike the coins. The obtained results are in good agreement with archaeological records.

Fibrinogen, Riboflavin, and UVA to Immobilize a Corneal Flap—Conditions for Tissue Adhesion

PubMed Central

Littlechild, Stacy L.; Brummer, Gage; Zhang, Yuntao; Conrad, Gary W.

2012-01-01

Purpose. Laser-assisted in situ keratomileus (LASIK) creates a permanent flap that remains non-attached to the underlying laser-modified stroma. This lack of permanent adhesion is a liability. To immobilize a corneal flap, a protocol using fibrinogen (FIB), riboflavin (RF), and ultraviolet (UVA) light (FIB+RF+UVA) was devised to re-adhere the flap to the stroma. Methods. A model flap was created using rabbit (Oryctolagus cuniculus) and shark (Squalus acanthias) corneas. Solutions containing FIB and RF were applied between corneal strips as glue. Experimental corneas were irradiated with long wavelength (365 nm) UVA. To quantify adhesive strength between corneal strips, the glue-tissue interface was subjected to a constant force while a digital force gauge recorded peak tension. Results. In the presence of FIB, substantive non-covalent interactions occurred between rabbit corneal strips. Adhesiveness was augmented if RF and UVA also were applied, suggesting formation of covalent bonds. Additionally, exposing both sides of rabbit corneas to UVA generated more adhesion than exposure from one side, suggesting that RF in the FIB solution catalyzes formation of covalent bonds at only the interface between stromal molecules and FIB closest to the UVA. In contrast, in the presence of FIB, shark corneal strips interacted non-covalently more substantively than those of rabbits, and adhesion was not augmented by applying RF+UVA, from either or both sides. Residual RF could be rinsed away within 1 hour. Conclusions. Glue solution containing FIB and RF, together with UVA treatment, may aid immobilization of a corneal flap, potentially reducing risk of flap dislodgement. PMID:22589434

[Are there guidelines for treatment of metacarpal fractures? Personal results and literature analysis of the last 12 years].

PubMed

Prokop, A; Kulus, S; Helling, H J; Burger, C; Rehm, K E

1999-01-01

As the treatment of metacarpal fractures is today still a controversial subject, we conducted an analysis of the literature in order to present the different therapy guidelines, indications, and their results. The data from the follow-up of 1602 patients was taken from literature which dated from 1 January 1984 to 31 March 1996. A total of 522 patients who underwent surgery received K-wires, screws or external minifixateur. The conservative approaches ranged from immobilization to various methods of mobilization with different aids or without fixation of the fracture. The mobilization in a brace provided good to excellent results in 95% of the cases; however, the failure rate of therapy was 23% because of local bruises and skin necrosis (3%). The mobilization with handcast, tape etc. attained good to excellent results in 94% of the cases. Here, no complications occurred. Both the immobilization treatment and the surgery provided good to excellent results in 85% of the cases. The reposition of fractures of the fifth metacarpal was successful in only 15% of the cases. Fractures with dislocations below 30 degrees, a shortening of less than 5 mm, no rotational displacement or that below 10 degrees, no articular incongruency, and no relevant soft tissue trauma do not need surgery according to our results and should be treated with early mobilization as suggested by the survey. Beyond these limits a primary surgical therapy is justified. The immobilization of metacarpal fractures over a period of more than 3-4 weeks is not necessary.

Acquisition of a Circular Dichroism Spectrometer to Study Biological Molecules at Interfaces

DTIC Science & Technology

2016-02-10

H133C double mutant) was immobilized by itself and co-immobilized with poly- sorbitol methacrylate on maleimide SAM surfaces. The purpose of this...work is to see whether the hydromimetic poly- sorbitol methacrylate can protect protein secondary structure when the co-immobilized protein-polymer...partially lost its secondary structure after the sample was exposed to air for 1 day. The co-immobilized NsfB-H360C-H133C double mutant and poly- sorbitol

Prevent and cure disuse bone loss

NASA Technical Reports Server (NTRS)

Jee, Webster S. S.

1994-01-01

Anabolic agents like parathyroid hormone and postagladin E-like substances were studied in dogs and rats to determine their effectiveness in the prevention and cure of bone loss due to immobilization. It was determined that postagladin E2 administration prevented immobilization while at the same time it added extra bone in a dose responsive manner. Although bone mass returns, poor trabecular architecture remains after normal ambulation recovery from immobilization. Disuse related bone loss and poor trabecular architecture were cured by post-immobilization postagladin E2 treatment.

Recovery of skeletal muscle after 3 mo of hindlimb immobilization in rats

NASA Technical Reports Server (NTRS)

Booth, F. W.; Seider, M. J.

1979-01-01

During immobilization, skeletal muscle undergoes decreases in size and strength with concomitant atrophic and degenerative changes in slow-twitch muscle fibers. Currently there are no objective data in slow-twitch muscle demonstrating recovery of biochemical or physiological indices following termination of immobilization. The purpose of this study was to determine whether the soleus, a slow-twitch muscle, could recover normal biochemical or physiological levels following termination of immobilization. Adenosine triphosphate, glycogen, and protein concentration (mg/g wet wt) all significantly decreased following 90 days of hindlimb immobilization, but these three values returned to control levels by the 60th recovery day. Similarly, soleus muscle wet weight and protein content (mg protein/muscle) returned to control levels by the 14th recovery day. In contrast, maximal isometric tension did not return to normal until the 120th day. These results indicate that following muscular atrophy, which was achieved through 90 days of hindlimb immobilization, several biochemical and physiological values in skeletal muscle are recovered at various times after the end of immobilization.

Enhancement of simultaneous algicidal and denitrification of immobilized Acinetobacter sp. J25 with magnetic Fe3O4 nanoparticles.

PubMed

Su, Jun Feng; Liang, Dong Hui; Huang, Ting Lin; Wei, Li; Ma, Min; Lu, Jinsuo

2017-07-01

In this study, immobilization technique was employed to improve simultaneous algicidal and denitrification of immobilized Acinetobacter sp. J25 with magnetic Fe 3 O 4 in eutrophic landscape water. After 7 days of operation, the maximum superoxide dismutase (SOD) activity (54.43 U mg -1 ), nitrate removal efficiency (100% (0.2127 mg L -1  h -1 )), and chlorophyll-a removal efficiency (89.71%) were obtained from the immobilized J25 with magnetic Fe 3 O 4 . The results suggest that immobilized J25 with magnetic Fe 3 O 4 had better nitrogen removal efficiency and algicidal activity in eutrophic landscape water. High-throughput sequencing data profiled the strain J25 that was immobilized with magnetic Fe 3 O 4 which changed the composition of the microbial community. The results indicated a novel concept of enhancing the algicidal and denitrification property of immobilized bacteria with magnetic Fe 3 O 4 in eutrophic landscape water.

Immobilization effects on the photocatalytic activity of CdS quantum Dots-Horseradish peroxidase hybrid nanomaterials.

PubMed

Iñarritu, Iker; Torres, Eduardo; Topete, Antonio; Campos-Terán, José

2017-11-15

The potential use of hybrid nanomaterials based on inorganic optically active nanoparticles known as quantum dots (QDs) and horseradish peroxidase (HRP) has been proposed by several authors as light-controllable nanocatalyzers, moreover, the immobilization within or over silica based supports represents an advantage over bulk-dispersed systems. However, the implications of the immobilization of such hybrid photoactivatable catalyzing systems have not been clarified with detail. Here, we present a thorough study of the functional photoactive efficiency and recycling of immobilized CdS QDs and HRP systems with different configurations, immobilized over silanized silica quartz crystal microbalance (QCM) sensors, allowing an accurate measure of the immobilized mass of each component and its correlation with the initial reaction rate of conversion of Amplex Red (AR) to resorufin. As well, the conversion efficiency is compared between the different systems and also to non-immobilized QD-HRP complexed systems. Copyright © 2017 Elsevier Inc. All rights reserved.

Immobilized acclimated biomass-powdered activated carbon for the bioregeneration of granular activated carbon loaded with phenol and o-cresol.

PubMed

Toh, Run-Hong; Lim, Poh-Eng; Seng, Chye-Eng; Adnan, Rohana

2013-09-01

The objectives of the study are to use immobilized acclimated biomass and immobilized biomass-powdered activated carbon (PAC) as a novel approach in the bioregeneration of granular activated carbon (GAC) loaded with phenol and o-cresol, respectively, and to compare the efficiency and rate of the bioregeneration of the phenolic compound-loaded GAC using immobilized and suspended biomasses under varying GAC dosages. Bioregeneration of GAC loaded with phenol and o-cresol, respectively, was conducted in batch system using the sequential adsorption and biodegradation approach. The results showed that the bioregeneration efficiency of GAC loaded with phenol or o-cresol was basically the same irrespective of whether the immobilized or suspended biomass was used. Nonetheless, the duration for bioregeneration was longer under immobilized biomass. The beneficial effect of immobilized PAC-biomass for bioregeneration is the enhancement of the removal rate of the phenolic compounds via adsorption and the shortening of the bioregeneration duration. Copyright © 2013 Elsevier Ltd. All rights reserved.

Modification of Immobead 150 support for protein immobilization: effects on the properties of immobilized Aspergillus oryzae β-galactosidase.

PubMed

Gennari, Adriano; Herrmann Mobayed, Francielle; da Silva Rafael, Ruan; Rodrigues, Rafael C; Sperotto, Raul Antonio; Volpato, Giandra; Volken de Souza, Claucia Fernanda

2018-05-01

We studied the modification of Immobead 150 support by either introducing aldehyde groups using glutaraldehyde (Immobead-Glu) or carboxyl groups through acid solution (Immobead-Ac) for enzyme immobilization by covalent attachment or ion exchange, respectively. These two types of immobilization were compared with the use of epoxy groups that are now provided on a commercial support. We used Aspergillus oryzae β-galactosidase (Gal) as a model protein, immobilizing it on unmodified (epoxy groups, Immobead-Epx) and modified supports. Immobilization yield and efficiency were tested as a function of protein loading (10 to 500 mg.g -1 support). Gal was efficiently immobilized on the Immobeads with an immobilization efficiency higher than 75% for almost all supports and protein loads. Immobilization yields significantly decreased when protein loadings were higher than 100 mg.g -1 support. Gal immobilized on Immobead-Glu and Immobead-Ac retained approximately 60% of its initial activity after 90 days of storage at 4°C. The three immobilized Gal derivatives presented higher half-lifes than the soluble enzyme, where the half-lifes were twice higher than the free Gal at 73°C. All the preparations were moderately operationally stable when tested in lactose solution, whey permeate, cheese whey, and skim milk, and retained approximately 50% of their initial activity after 20 cycles of hydrolyzing lactose solution. The modification of the support with glutaraldehyde provided the most stable derivative during cycling in cheese whey hydrolysis. Our results suggest that the Immobead 150 is a promising support for Gal immobilization. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

The vacuum splint: an aid in emergency splinting of fractures

PubMed Central

Letts, R. M.; Hobson, D. A.

1973-01-01

The vacuum splint has been shown to be a simple, safe and effective method of emergency splinting of fractured extremities. The splint is simply constructed from clear vinyl sheeting and contains 2-mm. expanded polystyrene balls. Evacuation of air causes the splint to become rigid, thereby providing stability and immobilization of the limb. The splint is radiolucent, containing no obstructive metal components that would interfere with the radiographic appearance of the injured limb. The ease of application of this splint makes it especially effective for the emergency splinting of fractures in children. ImagesFIG. 1FIG. 2AFIG. 2BFIG. 3FIG. 4 PMID:4742489

An overview of technologies for immobilization of enzymes and surface analysis techniques for immobilized enzymes

PubMed Central

Mohamad, Nur Royhaila; Marzuki, Nur Haziqah Che; Buang, Nor Aziah; Huyop, Fahrul; Wahab, Roswanira Abdul

2015-01-01

The current demands of sustainable green methodologies have increased the use of enzymatic technology in industrial processes. Employment of enzyme as biocatalysts offers the benefits of mild reaction conditions, biodegradability and catalytic efficiency. The harsh conditions of industrial processes, however, increase propensity of enzyme destabilization, shortening their industrial lifespan. Consequently, the technology of enzyme immobilization provides an effective means to circumvent these concerns by enhancing enzyme catalytic properties and also simplify downstream processing and improve operational stability. There are several techniques used to immobilize the enzymes onto supports which range from reversible physical adsorption and ionic linkages, to the irreversible stable covalent bonds. Such techniques produce immobilized enzymes of varying stability due to changes in the surface microenvironment and degree of multipoint attachment. Hence, it is mandatory to obtain information about the structure of the enzyme protein following interaction with the support surface as well as interactions of the enzymes with other proteins. Characterization technologies at the nanoscale level to study enzymes immobilized on surfaces are crucial to obtain valuable qualitative and quantitative information, including morphological visualization of the immobilized enzymes. These technologies are pertinent to assess efficacy of an immobilization technique and development of future enzyme immobilization strategies. PMID:26019635

[Immobilization of introduced bacteria and degradation of pyrene and benzo(alpha) pyrene in soil by immobilized bacteria].

PubMed

Wang, Xin; Li, Peijun; Song, Shouzhi; Zhong, Yong; Zhang, Hui; Verkhozina, E V

2006-11-01

In this study, introduced bacteria were applied in the bioremediation of pyrene and benzo (alpha) pyrene in organic pollutants-contaminated soils, aimed to test whether it was feasible to introduce bacteria to environmental engineering. Three introduced bacteria were immobilized separately or together to degrade the pyrene and benzo (alpha) pyrene in soil, taking dissociated bacteria as the control, and comparing with three indigenous bacteria. The results showed that immobilized introduced bacteria, either single or mixed, had higher degradation efficiency than dissociated bacteria. Compared with indigenous bacteria, some introduced bacteria had predominance to some degree. The introduced bacteria-mixture had better degradation efficiency after being immobilized. The degradation rate of pyrene and benzo(alpha) pyrene after treated with immobilized bacteria-( B61-B67)-mixture for 96 hours was 43.49% and 38.55%, respectively.

The Effect of Soft and Rigid Cervical Collars on Head and Neck Immobilization in Healthy Subjects.

PubMed

Barati, Kourosh; Arazpour, Mokhtar; Vameghi, Roshanak; Abdoli, Ali; Farmani, Farzad

2017-06-01

Whiplash injury is a prevalent and often destructive injury of the cervical column, which can lead to serious neck pain. Many approaches have been suggested for the treatment of whiplash injury, including anti-inflammatory drugs, manipulation, supervised exercise, and cervical collars. Cervical collars are generally divided into two groups: soft and rigid collars. The present study aimed to compare the effect of soft and rigid cervical collars on immobilizing head and neck motion. Many studies have investigated the effect of collars on neck motion. Rigid collars have been shown to provide more immobilization in the sagittal and transverse planes compared with soft collars. However, according to some studies, soft and rigid collars provide the same range of motion in the frontal plane. Twenty-nine healthy subjects aged 18-26 participated in this study. Data were collected using a three-dimensional motion analysis system and six infrared cameras. Eight markers, weighing 4.4 g and thickened 2 cm 2 were used to record kinematic data. According to the normality of the data, a paired t -test was used for statistical analyses. The level of significance was set at α=0.01. All motion significantly decreased when subjects used soft collars ( p <0.01). According to the obtained data, flexion and lateral rotation experienced the maximum (39%) and minimum (11%) immobilization in all six motions using soft collars. Rigid collars caused maximum immobilization in flexion (59%) and minimum immobilization in the lateral rotation (18%) and limited all motion much more than the soft collar. This study showed that different cervical collars have different effects on neck motion. Rigid and soft cervical collars used in the present study limited the neck motion in both directions. Rigid collars contributed to significantly more immobilization in all directions.

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

Cozzi, Alex D.; McCabe, Daniel J.

The Hanford Waste Treatment and Immobilization Plant (WTP) Low Activity Waste (LAW) vitrification facility will generate an aqueous condensate recycle stream (LAW Melter Off-Gas Condensate) from the off-gas system. The baseline plan for disposition of this stream during full WTP operations is to send it to the WTP Pretreatment Facility, where it will be blended with LAW, concentrated by evaporation and recycled to the LAW vitrification facility. However, during the Direct Feed LAW (DFLAW) scenario, planned disposition of this stream is to evaporate it in a new evaporator in the Effluent Management Facility (EMF) and then return it to themore » LAW melter. It is important to understand the composition of the effluents from the melter and new evaporator so that the disposition of these streams can be accurately planned and accommodated. Furthermore, alternate disposition of this stream would eliminate recycling of problematic components, and would enable less integrated operation of the LAW melter and the Pretreatment Facilities. Alternate disposition would also eliminate this stream from recycling within WTP when it begins operations and would decrease the LAW vitrification mission duration and quantity of glass waste. This LAW Melter Off-Gas Condensate stream will contain components that are volatile at melter temperatures and are problematic for the glass waste form, such as halides and sulfate, along with entrained, volatile, and semi-volatile metals, such as Hg, As, and Se. Because this stream will recycle within WTP, these components accumulate in the Melter Condensate stream, exacerbating their impact on the number of LAW glass containers that must be produced. Diverting the stream reduces the halides and sulfate that get recycled to the melter, and is a key objective of this work. This overall program examines the potential treatment and immobilization of this stream to enable alternative disposal. The objective of earlier tasks was to formulate and prepare a simulant of the LAW Melter Off-gas Condensate expected during DFLAW operations and use it in evaporator testing to predict the composition of the effluents from the Effluent Management Facility (EMF) evaporator to aid in planning for their disposition. The objective of this task was to test immobilization options for this evaporator bottoms aqueous stream. This document describes the method used to formulate a simulant of this EMF evaporator bottoms stream, immobilize it, and determine if the immobilized waste forms meet disposal criteria.« less

Lignin from bamboo shoot shells as an activator and novel immobilizing support for α-amylase.

PubMed

Gong, Weihua; Ran, Zhanxiang; Ye, Fayin; Zhao, Guohua

2017-08-01

This study examined the feasibility of α-amylase activation and immobilization, using lignin from bamboo shoot shells (BSS). Our results demonstrated that BSS lignin is an excellent α-amylase activator and it elevated α-amylase activity more than two-fold at a concentration of 5mg/ml. For immobilization of α-amylase via adsorption, BSS lignin was incubated in an α-amylase solution (5mg/ml) for 20min, and the maximum specific activity, amount of loaded protein and activity recovery were 92.4U/mg, 19.0mg/g and 111%, respectively. In contrast to its free counterpart, immobilized α-amylase improved the catalytic efficiency and storage stability, under comparable working conditions (temperature and pH). Regarding its convenient usage, immobilized enzyme can be suspended in advance, but a suspension incubated at 60°C should be used within 30min. The residual activity after 14 re-uses remained at a reasonable level (53.2%). In conclusion, this study reveals a novel support for enzyme immobilization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Immobilization of peroxidase enzyme onto the porous silicon structure for enhancing its activity and stability

NASA Astrophysics Data System (ADS)

Sahare, Padmavati; Ayala, Marcela; Vazquez-Duhalt, Rafael; Agrawal, Vivechana

2014-08-01

In this work, a commercial peroxidase was immobilized onto porous silicon (PS) support functionalized with 3-aminopropyldiethoxysilane (APDES) and the performance of the obtained catalytic microreactor was studied. The immobilization steps were monitored and the activity of the immobilized enzyme in the PS pores was spectrophotometrically determined. The enzyme immobilization in porous silicon has demonstrated its potential as highly efficient enzymatic reactor. The effect of a polar organic solvent (acetonitrile) and the temperature (up to 50°C) on the activity and stability of the biocatalytic microreactor were studied. After 2-h incubation in organic solvent, the microreactor retained 80% of its initial activity in contrast to the system with free soluble peroxidase that lost 95% of its activity in the same period of time. Peroxidase immobilized into the spaces of the porous silicon support would be perspective for applications in treatments for environmental security such as removal of leached dye in textile industry or in treatment of different industrial effluents. The system can be also applied in the field of biomedicine.

Laccase production by free and immobilized mycelia of Peniophora cinerea and Trametes versicolor: a comparative study.

PubMed

Silvério, Sara C; Moreira, Sérgio; Milagres, Adriane M F; Macedo, Eugénia A; Teixeira, José A; Mussatto, Solange I

2013-03-01

The production of laccase by immobilized mycelia of Peniophora cinerea and Trametes versicolor was studied. In an initial stage, experimental assays were performed in Erlenmeyer flasks using free and immobilized mycelium, and the performance of the fungal strains to produce the enzyme was compared. Both fungi adhered into the support material (a synthetic fiber), growing not only on the surface but also in the interspaces of the fibers. Immobilization of P. cinerea provided a 35-fold increase in laccase production when compared to the production obtained by using free mycelium. On the other hand, immobilization of T. versicolor caused a decrease in laccase activity. A comparison between the strains revealed that immobilized P. cinerea (3,500 U/L) surpassed the enzyme production by free T. versicolor (800 U/L). When the conditions that gave the best laccase production to each fungus were employed in a stirred tank bioreactor, very low laccase production was observed for both the cases, suggesting that shear stress and mycelia damage caused by the agitation impellers negatively affected the enzyme production.

An orientation analysis method for protein immobilized on quantum dot particles

NASA Astrophysics Data System (ADS)

Aoyagi, Satoka; Inoue, Masae

2009-11-01

The evaluation of orientation of biomolecules immobilized on nanodevices is crucial for the development of high performance devices. Such analysis requires ultra high sensitivity so as to be able to detect less than one molecular layer on a device. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has sufficient sensitivity to evaluate the uppermost surface structure of a single molecular layer. The objective of this study is to develop an orientation analysis method for proteins immobilized on nanomaterials such as quantum dot particles, and to evaluate the orientation of streptavidin immobilized on quantum dot particles by means of TOF-SIMS. In order to detect fragment ions specific to the protein surface, a monoatomic primary ion source (Ga +) and a cluster ion source (Au 3+) were employed. Streptavidin-immobilized quantum dot particles were immobilized on aminosilanized ITO glass plates at amino groups by covalent bonding. The reference samples streptavidin directly immobilized on ITO plates were also prepared. All samples were dried with a freeze dryer before TOF-SIMS measurement. The positive secondary ion spectra of each sample were obtained using TOF-SIMS with Ga + and Au 3+, respectively, and then they were compared so as to characterize each sample and detect the surface structure of the streptavidin immobilized with the biotin-immobilized quantum dots. The chemical structures of the upper surface of the streptavidin molecules immobilized on the quantum dot particles were evaluated with TOF-SIMS spectra analysis. The indicated surface side of the streptavidin molecules immobilized on the quantum dots includes the biotin binding site.

Effects of immobilization and whole-body vibration on rat serum Type I collagen turnover.

PubMed

Dönmez, Gürhan; Doral, Mahmut Nedim; Suljevic, Şenay; Sargon, Mustafa Fevzi; Bilgili, Hasan; Demirel, Haydar Ali

2016-08-01

The aim of this study was to investigate the effects of short-term, high-magnitude whole-body vibration (WBV) on serum type I collagen turnover in immobilized rats. Thirty Wistar albino rats were randomly divided into the following 5 groups: immobilization (IS), immobilization + remobilization (IR), immobilization + WBV (IV), control (C), and WBV control (CV). Immobilization was achieved by casting from the crista iliaca anterior superior to the lower part of the foot for 2 weeks. The applied WBV protocol involved a frequency of 45 Hz and amplitude of 3 mm for 7 days starting a day after the end of the immobilization period. Serum type I collagen turnover markers were measured by using ELISA kits. Serum NH2-terminal propeptide of type I collagen (PINP) levels were significantly lower in the immobilization groups (p < 0.02) compared with the control groups. Although WBV improved PINP levels in the control groups, there were no differences in PINP levels among the immobilization groups. Similarly, serum COOH-terminal telopeptide of type I collagen (CTX) levels were higher in the WBV controls than their own controls (p < 0,05). Immobilization led to deterioration of tendon tissue, as observed by histopathological analysis with a transmission electron microscope. Although 1 week of WBV had a positive effect on type I collagen turnover in controls, it is not an efficient method for repairing tissue damage in the early stage following immobilization. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

Soluble Milk Proteins Improve Muscle Mass Recovery after Immobilization-Induced Muscle Atrophy in Old Rats but Do not Improve Muscle Functional Property Restoration.

PubMed

Verney, J; Martin, V; Ratel, S; Chavanelle, V; Bargetto, M; Etienne, M; Chaplais, E; Le Ruyet, P; Bonhomme, C; Combaret, L; Guillet, C; Boisseau, N; Sirvent, P; Dardevet, D

2017-01-01

Effect of 3 different dairy protein sources on the recovery of muscle function after limb immobilization in old rats. Longitudinal animal study. Institut National de la Recherche Agronomique (INRA). The study took part in a laboratory setting. Old rats were subjected to unilateral hindlimb immobilization for 8 days and then allowed to recover with 3 different dietary proteins: casein, soluble milk proteins or whey proteins for 49 days. Body weight, muscle mass, muscle fibre size, isometric, isokinetic torque, muscle fatigability and muscle oxidative status were measured before and at the end of the immobilization period and during the recovery period i.e 7, 21, 35 and 49 days post immobilization. In contrast to the casein diet, soluble milk proteins and whey proteins were efficient to favor muscle mass recovery after cast immobilization during aging. By contrast, none of the 3 diary proteins was able to improve muscle strength, power and fatigability showing a discrepancy between the recovery of muscle mass and function. However, the soluble milk proteins allowed a better oxidative capacity in skeletal muscle during the rehabilitation period. Whey proteins and soluble milk proteins improve muscle mass recovery after immobilization-induced muscle atrophy in old rats but do not allow muscle functional property restoration.

Long-term C. elegans immobilization enables high resolution developmental studies in vivo.

PubMed

Berger, Simon; Lattmann, Evelyn; Aegerter-Wilmsen, Tinri; Hengartner, Michael; Hajnal, Alex; deMello, Andrew; Casadevall I Solvas, Xavier

2018-05-01

Live-imaging of C. elegans is essential for the study of conserved cellular pathways (e.g. EGFR/Wnt signaling) and morphogenesis in vivo. However, the usefulness of live imaging as a research tool has been severely limited by the need to immobilize worms prior to and during imaging. Conventionally, immobilization is achieved by employing both physical and chemical interventions. These are known to significantly affect many physiological processes, and thus limit our understanding of dynamic developmental processes. Herein we present a novel, easy-to-use microfluidic platform for the long-term immobilization of viable, normally developing C. elegans, compatible with image acquisition at high resolution, thereby overcoming the limitations associated with conventional worm immobilization. The capabilities of the platform are demonstrated through the continuous assessment of anchor cell (AC) invasion and distal tip cell (DTC) migration in larval C. elegans and germ cell apoptosis in adult C. elegans in vivo for the first time.

Immobilized lysozyme for the continuous lysis of lactic bacteria in wine: Bench-scale fluidized-bed reactor study.

PubMed

Cappannella, Elena; Benucci, Ilaria; Lombardelli, Claudio; Liburdi, Katia; Bavaro, Teodora; Esti, Marco

2016-11-01

Lysozyme from hen egg white (HEWL) was covalently immobilized on spherical supports based on microbial chitosan in order to develop a system for the continuous, efficient and food-grade enzymatic lysis of lactic bacteria (Oenococcus oeni) in white and red wine. The objective is to limit the sulfur dioxide dosage required to control malolactic fermentation, via a cell concentration typical during this process. The immobilization procedure was optimized in batch mode, evaluating the enzyme loading, the specific activity, and the kinetic parameters in model wine. Subsequently, a bench-scale fluidized-bed reactor was developed, applying the optimized process conditions. HEWL appeared more effective in the immobilized form than in the free one, when the reactor was applied in real white and red wine. This preliminary study suggests that covalent immobilization renders the enzyme less sensitive to the inhibitory effect of wine flavans. Copyright © 2016 Elsevier Ltd. All rights reserved.

Functionalized Graphene Sheets As Immobilization Matrix for Fenugreek β-Amylase: Enzyme Kinetics and Stability Studies

PubMed Central

Srivastava, Garima; Singh, Kritika; Talat, Mahe; Srivastava, Onkar Nath; Kayastha, Arvind M.

2014-01-01

β-Amylase finds application in food and pharmaceutical industries. Functionalized graphene sheets were customised as a matrix for covalent immobilization of Fenugreek β-amylase using glutaraldehyde as a cross-linker. The factors affecting the process were optimized using Response Surface Methodology based Box-Behnken design of experiment which resulted in 84% immobilization efficiency. Scanning and Transmission Electron Microscopy (SEM, TEM) and Fourier Tansform Infrared (FTIR) spectroscopy were employed for the purpose of characterization of attachment of enzyme on the graphene. The enzyme kinetic studies were carried out for obtaining best catalytic performance and enhanced reusability. Optimum temperature remained unchanged, whereas optimum pH showed shift towards acidic range for immobilized enzyme. Increase in thermal stability of immobilized enzyme and non-toxic nature of functionalized graphene can be exploited for production of maltose in food and pharmaceutical industries. PMID:25412079

Cellulase immobilization on magnetic nanoparticles encapsulated in polymer nanospheres.

PubMed

Lima, Janaina S; Araújo, Pedro H H; Sayer, Claudia; Souza, Antonio A U; Viegas, Alexandre C; de Oliveira, Débora

2017-04-01

Immobilization of cellulases on magnetic nanoparticles, especially magnetite nanoparticles, has been the main approach studied to make this enzyme, economically and industrially, more attractive. However, magnetite nanoparticles tend to agglomerate, are very reactive and easily oxidized in air, which has strong impact on their useful life. Thus, it is very important to provide proper surface coating to avoid the mentioned problems. This study aimed to investigate the immobilization of cellulase on magnetic nanoparticles encapsulated in polymeric nanospheres. The support was characterized in terms of morphology, average diameter, magnetic behavior and thermal decomposition analyses. The polymer nanospheres containing encapsulated magnetic nanoparticles showed superparamagnetic behavior and intensity average diameter about 150 nm. Immobilized cellulase exhibited broader temperature stability than in the free form and great reusability capacity, 69% of the initial enzyme activity was maintained after eight cycles of use. The magnetic support showed potential for cellulase immobilization and allowed fast and easy biocatalyst recovery through a single magnet.

Histological and compositional responses of bone to immobilization and other experimental conditions

NASA Technical Reports Server (NTRS)

Brown, R. J.; Niklowitz, W. J.

1985-01-01

Histological techniques were utilized for evaluating progressive changes in tibial compact bone in adult male monkeys during chronic studies of immobilization-associated osteopenia. The animals were restrained in a semirecumbent position which reduces normally occurring stresses in the lower extremities and results in bone mass loss. The longest immobilization studies were of seven months duration. Losses of haversian bone tended to occur predominatly in the proximal tibia and were characterized by increased activation with excessive depth of penetration of osteoclastic activity. There was no apparent regulation of the size and orientation of resorption cavities. Rapid bone loss seen during 10 weeks of immobilization appeared to be due to unrestrained osteoclastic activity without controls and regulation which are characteristic of adaptive systems. The general pattern of loss persisted throughout 7 months of immobilization. Clear cut evidence of a formation phase in haversian bone was seen only after two months of reambulation.

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".

Assessment on the decolourization of textile dye (Reactive Yellow) using Pseudomonas sp. immobilized on fly ash: Response surface methodology optimization and toxicity evaluation.

PubMed

Roy, Uttariya; Sengupta, Shubhalakshmi; Banerjee, Priya; Das, Papita; Bhowal, Avijit; Datta, Siddhartha

2018-06-18

This study focuses on the investigation of removal of textile dye (Reactive Yellow) by a combined approach of sorption integrated with biodegradation using low cost adsorbent fly ash immobilized with Pseudomonas sp. To ensure immobilization of bacterial species on treated fly ash, fly ash with immobilized bacterial cells was characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and fluorescence microscopy. Comparative batch studies were carried out using Pseudomonas sp, fly ash and immobilized Pseudomonas sp on flyash and were observed that immobilized Pseudomonas sp on flyash acted as better decolourizing agent. The optimized pH, temperature, and immobilized adsorbent dosage for highest percentage of dye removal were observed to be pH 6, 303 K, 1.2 g/L in all the cases. At optimum condition, the highest percentage of dye removal was found to be 88.51%, 92.62% and 98.72% for sorption (flyash), biodegradation (Pseudomonas sp) and integral approach (Pseudomonas sp on flyash) respectively. Optimization of operating parameters of textile dye decolourization was done by response surface methodology (RSM) using Design Expert 7 software. Phytotoxicity evaluation with Cicer arietinum revealed that seeds exposed to untreated dye effluents showed considerably lower growth, inhibited biochemical, and enzyme parameters with compared to those exposed to treated textile effluents. Thus this immobilized inexpensive technique could be used for removal of synthetic dyes present in textile wastewater. Copyright © 2018 Elsevier Ltd. All rights reserved.

Neutralization of acidic drainage by Cryptococcus sp. T1 immobilized in alginate beads.

PubMed

Okai, Masahiko; Suwa, Chisato; Nagaoka, Shintaro; Obara, Nobuo; Mitsuya, Daisuke; Kurihara, Ayako; Ishida, Masami; Urano, Naoto

2017-11-01

We isolated Cryptococcus sp. T1 from Lake Tazawa's acidic water in Japan. Cryptococcus sp. T1 neutralized an acidic casamino acid solution (pH 3.0) and released ammonia from the casamino acids to aid the neutralization. The neutralization volume was estimated to be approximately 0.4 mL/h. The casamino acids' amino acids decreased (1.24→0.15 mM); ammonia increased (0.22→0.99 mM). We neutralized acidic drainage water (1 L) from a Tamagawa River neutralization plant, which was run through the column with the T1-immobilized alginate beads at a flow rate of 0.5 mL/min, and observed that the viscosity, particle size and amounts of the alginate beads affected the acidic drainage neutralization with an increase of the pH value from 5.26 to 6.61 in the last fraction. An increase in the Al concentration decreased Cryptococcus sp. T1's neutralization ability. After 48 h, the pH of acidic water with 50 mg/L Al was apparently lower than that without Al. Almost no pH increase was observed at 75 mg/L.

Incidence of and risk factors for complications associated with halo-vest immobilization: a prospective, descriptive cohort study of 239 patients.

PubMed

van Middendorp, Joost J; Slooff, Willem-Bart M; Nellestein, W Ronald; Oner, F Cumhur

2009-01-01

Since high rates of serious complications, such as death and pneumonia, during halo-vest immobilization have been reported, there has been a tendency of restraint with regard to the use of the halo vest. However, the rate of complications in a high-volume center with sufficient experience is unknown. Our objective was to determine the incidence of and risk factors associated with complications during halo-vest immobilization. During a five-year period, a prospective cohort study was performed in a single, level-I trauma center that was also a tertiary referral center for spinal disorders. Data from all patients undergoing halo-vest immobilization were collected prospectively, and every complication was recorded. The primary outcome was the presence or absence of complications. Univariate regression analysis and regression modeling were used to analyze the results. In 239 patients treated with halo-vest immobilization, twenty-six major, seventy-two intermediate, and 121 minor complications were observed. Fourteen patients (6%) died during the treatment, although only one death was related directly to the immobilization and three were possibly related directly to the immobilization. Twelve patients (5%) acquired pneumonia during halo-vest immobilization. Patients older than sixty-five years did not have an increased risk of pneumonia (p = 0.543) or halo vest-related mortality (p = 0.467). Halo vest-related complications ranged from three patients (1%) with incorrect initial placement of the halo vest to twenty-nine patients (12%) with a pin-site infection. Pin-site infection was significantly related to pin penetration through the outer table of the skull (odds ratio, 4.34; 95% confidence interval, 1.22 to 15.51; p = 0.024). In 164 trauma patients treated only with halo-vest immobilization, cervical fractures with facet joint involvement or dislocations were significantly related to radiographic loss of alignment during follow-up (odds ratio, 2.81; 95% confidence interval, 1.06 to 7.44; p = 0.031). There are relatively low rates of mortality and pneumonia during halo-vest immobilization, and elderly patients do not have an increased risk of pneumonia or death related to halo-vest immobilization. Nevertheless, the total number of minor complications is substantial. This study confirms that awareness of and responsiveness to minor complications can prevent subsequent development of serious morbidities and perhaps reduce mortality.

Study of bone mineral metabolism. [during body immobilization, bed rest, and space flight

NASA Technical Reports Server (NTRS)

Palmer, H. E.

1975-01-01

The use of Sr-85 as an indicator of the skeletal location and relative amount of bone demineralization which occurs during immobilization of the body or body parts, bed-rest or space flight was studied. The bone mineral replacement which occurs after immobilization was measured rather than the bone loss which occurs during immobilization. In a study with two adult beagle dogs, the Sr-85 uptake in a leg which had been immobilized for two months was 400 percent higher than the uptake in the legs in regular use. This increased uptake probably resulted from only a few percent loss in bone mineral and indicates that losses less than one percent can be easily detected and located. The sensitivity, simplicity, and low radiation dose associated with the use of this method indicates that it should receive consideration for use on humans in bed-rest and space flight studies. Methods for measuring changes in total body nitrogen and in assisting the Johnson Space Center in calibrating a whole body counter for total body potassium measurements were also investigated.

An efficient TiO2 coated immobilized system for the degradation studies of herbicide isoproturon: durability studies.

PubMed

Verma, A; Prakash, N T; Toor, A P

2014-08-01

The investigation presents the observations on the use of cement beads for the immobilization of TiO2 for the degradation of herbicide isoproturon. The immobilized system was effective in degrading and mineralizing the herbicide for continuous thirty cycles without losing its durability. Catalyst was characterized by SEM-EDAX for checking the durability of the catalyst. The degradation rate followed first order kinetics as measured by change in absorption intensity in UV range as well as HPLC analysis. Two rounds of TiO2 coating on inert cement beads with average diameter 1.5cm at UV Intensity 25Wm(-2) calcined at 400°C were the optimized conditions for the degradation of herbicide isoproturon. More than 90% TOC and COD reduction along with ammonium ions generation (80%) confirmed the mineralization of isoproturon. Fixed bed baffled reactor studies under solar irradiations using the TiO2 immobilized beads confirmed 85% degradation after 6h. LC-MS studies confirmed the intermediates formation and their subsequent degradation using immobilized system. Copyright © 2014 Elsevier Ltd. All rights reserved.

A selective molecularly imprinted polymer for immobilization of acetylcholinesterase (AChE): an active enzyme targeted and efficient method.

PubMed

Demirci, Gökhan; Doğaç, Yasemin İspirli; Teke, Mustafa

2015-11-01

In the present study, we immobilized acetylcholinesterase (AChE) enzyme onto acetylcholine removed imprinted polymer and acetylcholine containing polymer. First, the polymers were produced with acetylcholine, substrate of AChE, by dispersion polymerization. Then, the enzyme was immobilized onto the polymers by using two different methods: In the first method (method A), acetylcholine was removed from the polymer, and then AChE was immobilized onto this polymer (acetylcholine removed imprinted polymer). In the second method (method B), AChE was immobilized onto acetylcholine containing polymer by affinity. In method A, enzyme-specific species (binding sites) occurred by removing acetylcholine from the polymer. The immobilized AChE reached 240% relative specific activity comparison with free AChE because the active enzyme molecules bounded onto the polymer. Transmission electron microscopy results were taken before and after immobilization of AChE for the assessment of morphological structure of polymer. Also, the experiments, which include optimum temperature (25-65 °C), optimum pH (3-10), thermal stability (4-70 °C), kinetic parameters, operational stability and reusability, were performed to determine the characteristic of the immobilized AChE. Copyright © 2015 John Wiley & Sons, Ltd.

Bioremediation of Petrochemical Wastewater Containing BTEX Compounds by a New Immobilized Bacterium Comamonas sp. JB in Magnetic Gellan Gum.

PubMed

Jiang, Bei; Zhou, Zunchun; Dong, Ying; Wang, Bai; Jiang, Jingwei; Guan, Xiaoyan; Gao, Shan; Yang, Aifu; Chen, Zhong; Sun, Hongjuan

2015-05-01

In this study, we investigated the bioremediation of petrochemical wastewater containing BTEX compounds by immobilized Comamonas sp. JB cells. Three kinds of magnetic nanoparticles were evaluated as immobilization supports for strain JB. After comparison with Fe3O4 and a-Fe2O3 nanoparticles, r-Fe2O3 nanoparticle was selected as the optimal immobilization support. The highest biodegradation activity of r-Fe2O3-magnetically immobilized cells was obtained when the concentration of r-Fe2O3 nanoparticle was 120 mg L(-1). Additionally, the recycling experiments demonstrated that the degradation activity of r-Fe2O3-magnetically immobilized cells was still high and led to less toxicity than untreated wastewater during the eight recycles. qPCR suggested the concentration of strain JB in r-Fe2O3-magnetically immobilized cells was evidently increased after eight cycles of degradation experiments. These results supported developing efficient biocatalysts using r-Fe2O3-magnetically immobilized cells and provided a promising technique for improving biocatalysts used in the bioremediation of not only petrochemical wastewater but also other hazardous wastewater.

Fe3O4/SiO2-g-PSStNa polymer nanocomposite microspheres (PNCMs) from a surface-initiated atom transfer radical polymerization (SI-ATRP) approach for pectinase immobilization.

PubMed

Lei, Zhongli; Ren, Na; Li, Yanli; Li, Na; Mu, Bo

2009-02-25

Polymer nanocomposite microspheres (PNCMs) as solid supports can improve the efficiency of immobilized enzymes by reducing diffusional limitation as well as by increasing the surface area per mass unit. In this work, pectinase was immobilized on Fe(3)O(4)/SiO2-g-poly(PSStNa) nanocomposite microspheres by covalent attachment. Biochemical studies showed an improved storage stability of the immobilized pectinase as well as enhanced performance at higher temperatures and over a wider pH range. The immobilized enzyme retained >50% of its initial activity over 30 days, and the optimum temperature and pH also increased to the ranges of 50-60 degrees C and 3.0-4.7, respectively. The kinetics of a model reaction catalyzed by the immobilized pectinase was finally investigated by the Michaelis-Menten equation. The PSStNa support presents a very simple, mild, and time-saving process for enzyme immobilization, and this strategy of immobilizing pectinase also makes use of expensive enzymes economically viable, strengthening repeated use of them as catalysts following their rapid and easy separation with a magnet.

Effects of the immobilization supports on the catalytic properties of immobilized mushroom tyrosinase: a comparative study using several substrates.

PubMed

Marín-Zamora, María Elisa; Rojas-Melgarejo, Francisco; García-Cánovas, Francisco; García-Ruiz, Pedro Antonio

2007-09-30

Mushroom tyrosinase was immobilized from an extract onto glass beads covered with one of the following compounds: the crosslinked totally cinnamoylated derivatives of glycerine, D-sorbitol, D-manitol, 1,2-O-isopropylidene-alpha-D-glucofuranose, D-glucuronic acid, D-gulonic acid, sucrose, D-glucosone, D-arabinose, D-fructose, D-glucose, ethyl-D-glucopyranoside, inuline, dextrine, dextrane or starch, or the partially cinnamoylated derivative 3,5,6-tricinnamoyl-D-glucofuranose which was obtained by the acid hydrolysis of 1,2-O-isopropylidene-alpha-d-glucofuranose. The enzyme was immobilized by direct adsorption onto the support and the quantity of tyrosinase immobilized was found to increase with the hydrophobicity of the supports. The kinetic constants of immobilized tyrosinase acting on the substrates, 4-tert-butylcatechol, dopamine and DL-dopa, were studied. When immobilized tyrosinase acted on 4-tert-butylcatechol, the values of K(m)(app) were lower than these obtained for tyrosinase in solution while, when dopamine and DL-dopa were used, the K(m)(app) were higher. The order of the substrates as regards their ionizable groups, DL-dopa (two ionizable groups)>dopamine (one ionizable group)>4-tert-butylcatechol (no ionizable group) coincided with the order of the K(m)(app) values shown by tyrosinase immobilized on the hydrophobic supports, and was the inverse of that observed for tyrosinase in solution. The K(m)(app) values of immobilized tyrosinase were in all cases higher than those of soluble tyrosinase and depended on the nature of the support and the hydrophobicity of the substrate, meaning that it is possible to design supports with different degrees of selectivity towards a mixture of enzyme substrates in the reaction medium.

Yeast Immobilization Systems for Alcoholic Wine Fermentations: Actual Trends and Future Perspectives

PubMed Central

Moreno-García, Jaime; García-Martínez, Teresa; Mauricio, Juan C.; Moreno, Juan

2018-01-01

Yeast immobilization is defined as the physical confinement of intact cells to a region of space with conservation of biological activity. The use of these methodologies for alcoholic fermentation (AF) offers many advantages over the use of the conventional free yeast cell method and different immobilization systems have been proposed so far for different applications, like winemaking. The most studied methods for yeast immobilization include the use of natural supports (e.g., fruit pieces), organic supports (e.g., alginate), inorganic (e.g., porous ceramics), membrane systems, and multi-functional agents. Some advantages of the yeast-immobilization systems include: high cell densities, product yield improvement, lowered risk of microbial contamination, better control and reproducibility of the processes, as well as reuse of the immobilization system for batch fermentations and continuous fermentation technologies. However, these methods have some consequences on the behavior of the yeasts, affecting the final products of the fermentative metabolism. This review compiles current information about cell immobilizer requirements for winemaking purposes, the immobilization methods applied to the production of fermented beverages to date, and yeast physiological consequences of immobilization strategies. Finally, a recent inter-species immobilization methodology has been revised, where yeast cells are attached to the hyphae of a Generally Recognized As Safe fungus and remain adhered following loss of viability of the fungus. The bio-capsules formed with this method open new and promising strategies for alcoholic beverage production (wine and low ethanol content beverages). PMID:29497415

Comparative cardiopulmonary effects of carfentanil-xylazine and medetomidine-ketamine used for immobilization of mule deer and mule deer/white-tailed deer hybrids.

PubMed Central

Caulkett, N A; Cribb, P H; Haigh, J C

2000-01-01

Three mule deer and 4 mule deer/white-tailed deer hybrids were immobilized in a crossover study with carfentanil (10 microg/kg) + xylazine (0.3 mg/kg) (CX), and medetomidine (100 microg/kg) + ketamine (2.5 mg/kg) (MK). The deer were maintained in left lateral recumbency for 1 h with each combination. Deer were immobilized with MK in 230+/-68 s (mean +/- SD) and with CX in 282+/-83 seconds. Systolic, mean and diastolic arterial pressure were significantly higher with MK. Heart rate, PaO2, PaCO2, pH, and base excess were not significantly different between treatments. Base excess and pH increased significantly over time with both treatments. Both treatments produced hypoventilation (PaCO2 > 50 mm Hg) and hypoxemia (PaO2 < 60 mm Hg). PaO2 increased significantly over time with CX. Body temperature was significantly (P<0.05) higher with CX compared to MK. Ventricular premature contractions, atrial premature contractions, and a junctional escape rhythm were noted during CX immobilization. No arrhythmias were noted during MK immobilization. Quality of immobilization was superior with MK, with no observed movement present for the 60 min of immobilization. Movement of the head and limbs occurred in 4 animals immobilized with CX. The major complication observed with both of these treatments was hypoxemia, and supplemental inspired oxygen is recommended during immobilization. Hyperthermia can further complicate immobilization with CX, reinforcing the need for supplemental oxygen. PMID:10680659

Morphodynamics of semi-alluvial streams in northern Fennoscandia: a flume experiment to determine bedform self-organization

NASA Astrophysics Data System (ADS)

Polvi, Lina

2017-04-01

Streams in northern Fennoscandia have two characteristics that complicate a process-based understanding of sediment transport affecting channel form: (1) they are typically semi-alluvial, in that they contain coarse glacial legacy sediment, and (2) numerous mainstem lakes buffer sediment and water fluxes. Systematic studies of these streams are complicated because natural reference sites are lacking due to over a century of widespread channel simplification to aid timber-floating. This research is part of a larger project to determine controls on channel geometry and sediment transport at: (1) the catchment scale, examining downstream hydraulic geometry, (2) the reach scale, examining sediment transport, and (3) the bedform scale, examining the potential for predictable bedform formation. The objective of the current study, targeting the bedform scale, was to use a flume experiment to determine whether sediment self-organizes and creates bedforms in semi-alluvial channels. The prototype channels, tributaries to the unregulated Vindel River in northern Sweden that are being restored after timber-floating, contain coarse sediment (D16: 55 mm, D50:250 mm, D84:620 mm) with moderately steep slopes (2-5%) and typically experience snowmelt-flooding and flooding due to ice jams. Using a scaling factor of 8 for Froude number similitude, an 8-m long, 1.1 m wide fixed-bed flume was set up at the Colorado State University Engineering Research Center with a scaled-down sediment distribution analogous to the prototype channels. For two flume setups, with bed slopes of 2% and 5%, four runs were conducted with flows analogous to QBF, Q2, Q10 and Q50 flows in the prototype channels until equilibrium conditions were reached. Digital elevation models (DEMs) of bed topography were constructed before and after each run using structure-from-motion photogrammetry. To examine self-organization of sediment, DEMs of difference between pre-flow conditions and after each flow were created; scour and deposition in relation to large immobile clasts were examined. Preliminary results show that at high flows at the lower slope (2%), fine sediment was deposited above immobile clasts and scour was common below. High flows at the higher slope (5%) caused scour above and occasionally directly below immobile clasts, with fine sediment deposited nearby scour zones above immobile clasts. These results indicate that these channels experience a shielding effect by large immobile clasts, inhibiting bedload transport and creating pockets of fine sediment upstream of large boulders. Additionally, pools downstream of immobile boulders may experience velocity reversals, causing scour instead of deposition in low-velocity zones. In addition, the combined aggradation and degradation between the Q50 and Q10 flows was less than between the Q10 and Q2 flows. This is most likely because the snowmelt-dominated flow regime of northern Sweden with buffering capacity of lakes precludes extremely high flows, causing a small difference in intermediate- and high-recurrence interval flow magnitudes. Therefore, flows with an intermediate recurrence interval likely do the most geomorphic work, but major sediment self-organization as seen in alluvial mountain streams is unlikely barring an extreme event. In conclusion, classical slope-dependent bedform relationships found in alluvial gravel-bed streams may not be applicable in semi-alluvial channels in northern Fennoscandia.

Analysis of agalacto-IgG in rheumatoid arthritis using surface plasmon resonance.

PubMed

Liljeblad, M; Lundblad, A; Påhlsson, P

2000-05-01

It is well established that IgG from rheumatoid arthritis (RA) patients are less galactosylated than IgG from normal individuals. Determination of agalacto-IgG may therefore aid in diagnosis and treatment of RA. The decrease in galactosylation of IgG leads to an increase in terminal N-acetylglucosamine residues, which can be detected using a specific lectin from Psathyrella velutina. In the present study IgG from RA and control serum was purified using affinity chromatography. The samples were then, after reduction, analyzed on a BIOCORE 2000 system with immobilized Psathyrella velutina lectin. Using this technique it was possible to discriminate between IgG from RA patients and IgG from control individuals with respect to its content of IgG with terminal N-acetylglucosamine. The affinity biosensor technique makes it possible to detect binding without labeling or using secondary antibodies.

Ergonomics intervention on an alternative design of a spinal board.

PubMed

Zadry, Hilma Raimona; Susanti, Lusi; Rahmayanti, Dina

2017-09-01

A spinal board is the evacuation tool of first aid to help the injured spinal cord. The existing spinal board has several weaknesses, both in terms of user comfort and the effectiveness and efficiency of the evacuation process. This study designs an ergonomic spinal board using the quality function deployment approach. A preliminary survey was conducted through direct observation and interviews with volunteers from the Indonesian Red Cross. Data gathered were translated into a questionnaire and answered by 47 participants in West Sumatra. The results indicate that the selection of materials, the application of strap systems as well as the addition of features are very important in designing an ergonomic spinal board. The data were used in designing an ergonomic spinal board. The use of anthropometric data ensures that this product can accommodate safety and comfort when immobilized, as well as the flexibility and speed of the rescue evacuation process.

Silurian K-bentonites of the Dnestr Basin, Podolia, Ukraine

USGS Publications Warehouse

Huff, W.D.; Bergstrom, Stig M.; Kolata, Dennis R.

2000-01-01

The Dnestr Basin of Podolia, Ukraine, is an epicratonic basin consisting of neritic carbonate and calcareous mudstone facies including a nearly complete Silurian sequence ranging from late Llandovery to late Pridoli in age. The Silurian section has served as a standard for regional and interregional studies as a consequence of its well-documented macro- and microfaunal assemblages. Approximately 24 mid- to Late Silurian K-bentonites are present in this succession, and their lateral persistence has aided in establishing regional correlations. The K-bentonites range from 1 to 40 cm in thickness and occur in the Bagovitsa (late Wenlock), Malinovtsy (Ludlow) and Skala (Pridoli) Formations. Discrimination diagrams based on immobile trace elements together with rare earth element data suggest the K-bentonites had a volcanic origin in a collision margin setting related to subduction. Thickness and stratigraphic distribution considerations are consistent with a source area in the Rheic Ocean.

Self-powered enzyme micropumps

NASA Astrophysics Data System (ADS)

Sengupta, Samudra; Patra, Debabrata; Ortiz-Rivera, Isamar; Agrawal, Arjun; Shklyaev, Sergey; Dey, Krishna K.; Córdova-Figueroa, Ubaldo; Mallouk, Thomas E.; Sen, Ayusman

2014-05-01

Non-mechanical nano- and microscale pumps that function without the aid of an external power source and provide precise control over the flow rate in response to specific signals are needed for the development of new autonomous nano- and microscale systems. Here we show that surface-immobilized enzymes that are independent of adenosine triphosphate function as self-powered micropumps in the presence of their respective substrates. In the four cases studied (catalase, lipase, urease and glucose oxidase), the flow is driven by a gradient in fluid density generated by the enzymatic reaction. The pumping velocity increases with increasing substrate concentration and reaction rate. These rechargeable pumps can be triggered by the presence of specific analytes, which enables the design of enzyme-based devices that act both as sensor and pump. Finally, we show proof-of-concept enzyme-powered devices that autonomously deliver small molecules and proteins in response to specific chemical stimuli, including the release of insulin in response to glucose.

Bioremediation of uranium-contaminated groundwater: a systems approach to subsurface biogeochemistry.

PubMed

Williams, Kenneth H; Bargar, John R; Lloyd, Jonathan R; Lovley, Derek R

2013-06-01

Adding organic electron donors to stimulate microbial reduction of highly soluble U(VI) to less soluble U(IV) is a promising strategy for immobilizing uranium in contaminated subsurface environments. Studies suggest that diagnosing the in situ physiological status of the subsurface community during uranium bioremediation with environmental transcriptomic and proteomic techniques can identify factors potentially limiting U(VI) reduction activity. Models which couple genome-scale in silico representations of the metabolism of key microbial populations with geochemical and hydrological models may be able to predict the outcome of bioremediation strategies and aid in the development of new approaches. Concerns remain about the long-term stability of sequestered U(IV) minerals and the release of co-contaminants associated with Fe(III) oxides, which might be overcome through targeted delivery of electrons to select microorganisms using in situ electrodes. Copyright © 2012 Elsevier Ltd. All rights reserved.

MICP and Advances towards Eco-Friendly and Economical Applications

NASA Astrophysics Data System (ADS)

Rajasekar, Adharsh; Moy, Charles K. S.; Wilkinson, Stephen

2017-07-01

Biomineralization is a natural process aided by living organisms. Due to its applicability in ground improvement and bioremediation, Microbially Induced Calcite Precipitation (MICP) is an interdisciplinary field of study combining engineering, chemistry and microbiology. Bioremediation has been applied widely for contamination containment or removal, in this case it will be containment. MICP can also be applied to improve the efficiency of insitu bioremediation. Urease is an enzyme which can facilitate increased calcite precipitation. However the production of urease by bacteria and thus the resulting carbonate precipitation are inhibited by environmental factors including calcium concentration, bacterial concentration, pH and temperature. Under good conditions MICP can be used for heavy metal and radionuclide immobilization. However technologies such as bioconsolidation and biocementation require improvement such as time and cost. This paper highlights the application of MICP in addition to suggested improvements to make it more eco-friendly and sustainable.

Nature and nurture: environmental influences on a genetic rat model of depression.

PubMed

Mehta-Raghavan, N S; Wert, S L; Morley, C; Graf, E N; Redei, E E

2016-03-29

In this study, we sought to learn whether adverse events such as chronic restraint stress (CRS), or 'nurture' in the form of environmental enrichment (EE), could modify depression-like behavior and blood biomarker transcript levels in a genetic rat model of depression. The Wistar Kyoto More Immobile (WMI) is a genetic model of depression that aided in the identification of blood transcriptomic markers, which successfully distinguished adolescent and adult subjects with major depressive disorders from their matched no-disorder controls. Here, we followed the effects of CRS and EE in adult male WMIs and their genetically similar control strain, the Wistar Kyoto Less Immobile (WLI), that does not show depression-like behavior, by measuring the levels of these transcripts in the blood and hippocampus. In WLIs, increased depression-like behavior and transcriptomic changes were present in response to CRS, but in WMIs no behavioral or additive transcriptomic changes occurred. Environmental enrichment decreased both the inherent depression-like behavior in the WMIs and the behavioral difference between WMIs and WLIs, but did not reverse basal transcript level differences between the strains. The inverse behavioral change induced by CRS and EE in the WLIs did not result in parallel inverse expression changes of the transcriptomic markers, suggesting that these behavioral responses to the environment work via separate molecular pathways. In contrast, 'trait' transcriptomic markers with expression differences inherent and unchanging between the strains regardless of the environment suggest that in our model, environmental and genetic etiologies of depression work through independent molecular mechanisms.

Stability of immobilization remediation of several amendments on cadmium contaminated soils as affected by simulated soil acidification.

PubMed

Guo, Fuyu; Ding, Changfeng; Zhou, Zhigao; Huang, Gaoxiang; Wang, Xingxiang

2018-06-04

Chemical immobilization is a practical approach to remediate heavy metal contamination in agricultural soils. However, the potential remobilization risks of immobilized metals are a major environmental concern, especially in acid rain zones. In the present study, changes in the immobilization efficiency of several amendments as affected by simulated soil acidification were investigated to evaluate the immobilization remediation stability of several amendments on two cadmium (Cd) contaminated soils. Amendments (hydrated lime, hydroxyapatite and biochar) effectively immobilized Cd, except for organic fertilizer, and their immobilizations were strongly decreased by the simulated soil acidification. The ratio of changes in CaCl 2 -extractable Cd: pH (△CaCl 2 -Cd/△pH) can represent the Cd remobilization risk of different amended soils. Hydroxyapatite and biochar had a stronger durable immobilizing effect than did hydrated lime, particularly in soil with a lower pH buffering capacity, which was further confirmed by the Cd concentration and accumulation in lettuce. These results can be attributed to that hydroxyapatite and biochar transformed greater proportions of exchangeable Cd to other more stable fractions than lime. After 48 weeks of incubation, in soil with a lower pH buffering capacity, the immobilization efficiencies of lime, hydroxyapatite, biochar and organic fertilizer in the deionized water group (pH 6.5) were 71.7%, 52.7%, 38.6% and 23.9%, respectively, and changed to 19.1%, 33.6%, 26.5% and 5.0%, respectively, in the simulated acid rain group (pH 2.5). The present study provides a simple method to preliminarily estimate the immobilization efficiency of amendments and predict their stability in acid rain regions before large-scale field application. In addition, hydrated lime is recommended to be combined with other acid-stable amendments (such as hydroxyapatite or biochar) to remediate heavy metal-contaminated agricultural soils in acid precipitation zones. Copyright © 2018 Elsevier Inc. All rights reserved.

Immobilization of alkaline phosphatase on solid surface through self-assembled monolayer and by active-site protection.

PubMed

Gao, En-Feng; Kang, Kyung Lhi; Kim, Jeong Hee

2014-06-01

Retaining biological activity of a protein after immobilization is an important issue and many studies reported to enhance the activity of proteins after immobilization. We recently developed a new immobilization method of enzyme using active-site protection and minimization of the cross-links between enzyme and surface with a DNA polymerase as a model system. In this study, we extended the new method to an enzyme with a small mono-substrate using alkaline phosphatase (AP) as another model system. A condition to apply the new method is that masking agents, in this case its own substrate needs to stay at the active-site of the enzyme to be immobilized in order to protect the active-site during the harsh immobilization process. This could be achieved by removal of essential divalent ion, Zn2+ that is required for full enzyme activity of AP from the masking solution while active-site of AP was protected with p-nitrophenyl phosphate (pNPP). Approximately 40% of the solution-phase activity was acquired with active-site protected immobilized AP. In addition to protection active-site of AP, the number of immobilization links was kinetically controlled. When the mole fraction of the activated carboxyl group of the linker molecule in self-assembled monolayer (SAM) of 12-mercaptododecanoic acid and 6-mercapto-1-ethanol was varied, 10% of 12-mercaptododecanoic acid gave the maximum enzyme activity. Approximately 51% increase in enzyme activity of the active-site protected AP was observed compared to that of the unprotected group. It was shown that the concept of active-site protection and kinetic control of the number of covalent immobilization bonds can be extended to enzymes with small mono-substrates. It opens the possibility of further extension of the new methods of active-site protection and kinetic control of immobilization bond to important enzymes used in research and industrial fields.

Stabilization of α-amylase by using anionic surfactant during the immobilization process

NASA Astrophysics Data System (ADS)

El-Batal, A. I.; Atia, K. S.; Eid, M.

2005-10-01

This work describes the entrapment of α-amylase into butylacrylate-acrylic acid copolymer (BuA/AAc) using γ irradiation. The effect of an anionic surfactant (AOT), the reuse efficiency, and kinetic behavior of immobilized α-amylase were studied. Covering of α-amylase with bis-(2-ethylhexyl)sulfosuccinate sodium salt (AOT) made the enzyme more stable than the uncovered form. The hydrolytic activity of the pre-coated immobilized α-amylase was increased below the critical micelle concentration (cmc) (10 mmol/L). The results showed an increase in the relative activity with increase in the degree of hydration. The pre-coated immobilized α-amylase showed a higher k/K and lower activation energy compared to the free and uncoated-immobilized preparation, respectively. The results suggest that the immobilization of α-amylase is a potentially useful approach for commercial starch hydrolysis in two-phase systems.

Covalent immobilization of penicillin G acylase on aminopropyl-functionalized mesostructured cellular foams.

PubMed

Zhao, Junqi; Wang, Yujun; Luo, Guangsheng; Zhu, Shenlin

2010-10-01

Mesostructured cellular foams (MCFs) are suitable for biomolecular immobilization because of their relatively large-pore diameter and pore volume. Penicillin G acylase (PGA) was immobilized on aminopropyl-functionalized MCFs through Schiff base reaction. It is shown that PGA could be fixed more firmly through the covalent immobilization on aminopropyl-functionalized MCFs support than through the adsorption immobilization on blank MCFs. The PGA loading amount on the aminopropyl-functionalized MCFs could reach 443 mg/g (dry support), and the apparent activity could achieve up to 4138 U/g (dry support). The influence of the amount of grafted aminopropyl group was studied, and it is found that the optimal molar ratio of MCFs to APTS was 15/1; in addition, the suitable enzyme distribution density for the specific activity of the immobilized PGA was 0.7 mg enzyme per m(2) of specific area of MCFs. Copyright 2010 Elsevier Ltd. All rights reserved.

Characterization of a new stationary phase based on microwave immobilized polybutadiene on titanium oxide-modified silica.

PubMed

Morais, Lais S R; Jardim, Isabel C S F

2005-05-06

Titanium oxide-modified silica was prepared by reaction of silica with titanium tetrabutoxide and then was used as support in the preparation of stationary phases with self-immobilized polybutadiene (PBD) and PBD immobilized through microwave radiation. Chromatographic performance of the stationary phases was evaluated in terms of the efficiency (plates/m), asymmetry (A(s)), retention factor (k) and resolution (R(s)) of two standard sample mixtures, one of then containing the basic compound N,N-dimethylaniline. A microwave irradiation of 30 min at 520 W gave the best efficiency (86,500 N m(-1)), greater than that of a 6-day self immobilized phase (69,500 N m(-1)). Self-immobilized stationary phases prepared with bare silica were also studied for comparison. These resulted in lower chromatographic performance, 43,800 N m(-1), when compared to the self-immobilized phase prepared with titanized silica.

Astaxanthin supplementation attenuates immobilization-induced skeletal muscle fibrosis via suppression of oxidative stress.

PubMed

Maezawa, Toshiyuki; Tanaka, Masayuki; Kanazashi, Miho; Maeshige, Noriaki; Kondo, Hiroyo; Ishihara, Akihiko; Fujino, Hidemi

2017-09-01

Immobilization induces skeletal muscle fibrosis characterized by increasing collagen synthesis in the perimysium and endomysium. Transforming growth factor-β1 (TGF-β1) is associated with this lesion via promoting differentiation of fibroblasts into myofibroblasts. In addition, reactive oxygen species (ROS) are shown to mediate TGF-β1-induced fibrosis in tissues. These reports suggest the importance of ROS reduction for attenuating skeletal muscle fibrosis. Astaxanthin, a powerful antioxidant, has been shown to reduce ROS production in disused muscle. Therefore, we investigated the effects of astaxanthin supplementation on muscle fibrosis under immobilization. In the present study, immobilization increased the collagen fiber area, the expression levels of TGF-β1, α-smooth muscle actin, and superoxide dismutase-1 protein and ROS production. However, these changes induced by immobilization were attenuated by astaxanthin supplementation. These results indicate the effectiveness of astaxanthin supplementation on skeletal muscle fibrosis induced by ankle joint immobilization.

Effect of consecutive cooling and immobilization on catecholamine metabolism in rat tissues

NASA Technical Reports Server (NTRS)

Matlina, E. S.; Waysman, S. M.; Zaydner, I. G.; Kogan, B. M.; Nozdracheva, L. V.

1979-01-01

The combined effect of two stressor stimuli--cooling and immobilization--acting successively on the sympathetic-adrenaline system was studied experimentally in rats that were cooled for 8 hours at 7 C on the first day and immobilized for 6 hours on the next day. The biochemical and histochemical methods used and the experimental technique involved are described in detail. The following conclusions were formulated: (1) the successive action of cooling and immobilization results in a stronger decrease in the adrenaline and noradrenaline content in the adrenal gland than that which could be due to a simple summation of the cooling and immobilization effects; (2) successive cooling and immobilization are followed by activation of catecholamine synthesis in the adrenal gland; and (3) 1-DOPA administration (45 mg/kg 3 times in 2 days) intraabdominally activated catecholamine synthesis in the adrenal glands in both the control and test animals.

Evaluation of the safety of C-spine clearance by paramedics: design and methodology

PubMed Central

2011-01-01

Background Canadian Emergency Medical Services annually transport 1.3 million patients with potential neck injuries to local emergency departments. Less than 1% of those patients have a c-spine fracture and even less (0.5%) have a spinal cord injury. Most injuries occur before the arrival of paramedics, not during transport to the hospital, yet most patients are transported in ambulances immobilized. They stay fully immobilized until a bed is available, or until physician assessment and/or X-rays are complete. The prolonged immobilization is often unnecessary and adds to the burden of already overtaxed emergency medical services systems and crowded emergency departments. Methods/Design The goal of this study is to evaluate the safety and potential impact of an active strategy that allows paramedics to assess very low-risk trauma patients using a validated clinical decision rule, the Canadian C-Spine Rule, in order to determine the need for immobilization during transport to the emergency department. This cohort study will be conducted in Ottawa, Canada with one emergency medical service. Paramedics with this service participated in an earlier validation study of the Canadian C-Spine Rule. Three thousand consecutive, alert, stable adult trauma patients with a potential c-spine injury will be enrolled in the study and evaluated using the Canadian C-Spine Rule to determine the need for immobilization. The outcomes that will be assessed include measures of safety (numbers of missed fractures and serious adverse outcomes), measures of clinical impact (proportion of patients transported without immobilization, key time intervals) and performance of the Rule. Discussion Approximately 40% of all very low-risk trauma patients could be transported safely, without c-spine immobilization, if paramedics were empowered to make clinical decisions using the Canadian C-Spine Rule. This safety study is an essential step before allowing all paramedics across Canada to selectively immobilize trauma victims before transport. Once safety and potential impact are established, we intend to implement a multi-centre study to study actual impact. Trial Registration ClinicalTrials.gov NCT01188447 PMID:21284880

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-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 mapping of elemental distribution in arbuscular mycorrhizal roots of the grass, Cynodon dactylon, from gold and uranium mine tailings

NASA Astrophysics Data System (ADS)

Weiersbye, I. M.; Straker, C. J.; Przybylowicz, W. J.

1999-10-01

A combination of PIXE, proton back-scattering (BS) spectrometry and confocal laser scanning microscopy (CLSM) was used to determine in situ elemental concentrations in arbuscular mycorrhizal (AM) grass roots and AM fungal spores from gold and uranium mine tailings in South Africa. AM regions of roots were characterised by locally elevated P and vesicles were defined by distinctive transition metal and radionuclide distributions. Vesicles (AM structures responsible for nutrient storage), accumulated Mn, Cu, Ni and U, whereas Fe and Zn were present at lower levels than in host tissue. AM spores from mine tailings accumulated Ca, Cr, Fe, Ni, Cu, Br, Y, Th and U, but were deficient in P and K. The sequestration of excess metals and radionuclides in vesicles may limit metal availability, and thus toxicity, to the host.

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.

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.

Application of micron X-ray CT based on micro-PIXE to investigate the distribution of Cs in silt particles for environmental remediation in Fukushima Prefecture

NASA Astrophysics Data System (ADS)

Ishii, Keizo; Hatakeyama, Taisuke; Itoh, Shin; Sata, Daichi; Ohnuma, Tohru; Yamaguchi, Toshiro; Arai, Hiromu; Arai, Hirotsugu; Matsuyama, Shigeo; Terakawa, Atsuki; Kim, Seong-Yun

2016-03-01

We used X-ray computed tomography (CT) using characteristic X-rays produced in micro-particle-induced X-ray emission (PIXE) to investigate the internal structure of silt particles and develop new methods to decontaminate soil containing radioactive cesium. We obtained 3D attenuation coefficient images of silt particles with a diameter of approximately 100 μm for V K and Cr K X-rays. Owing to the absorption edges of the Cs L-shell, the differences between the V K and Cr K X-ray images revealed the spatial distribution of Cs atoms in the silt particles. Cs atoms were distributed over the surfaces of the silt particles to a thickness of approximately 10 μm. This information is useful for the decontamination of silt contaminated by radiation from the Fukushima Daiichi nuclear disaster.

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.

Volatility in the lunar crust: Trace element analyses of lunar minerals by PIXE proton microprobe

NASA Technical Reports Server (NTRS)

Norman, M. D.; Griffin, W. L.; Ryan, C. G.

1993-01-01

In situ determination of mineral compositions using microbeam techniques can characterize magma compositions through mineral-melt partitioning, and be used to investigate fine-grained or rare phases which cannot be extracted for analysis. Abundances of Fe, Mn, Sr, Ga, Zr, Y, Nb, Zn, Cu, Ni, Se, and Sb were determined for various mineral phases in a small number of lunar highlands rocks using the PIXE proton microprobe. Sr/Ga ratios of plagioclase and Mn/Zn ratios of mafic silicates show that the ferroan anorthosites and Mg-suite cumulates are depleted in volatile lithophile elements to about the same degree compared with chondrites and the Earth. This links the entire lunar crust to common processes or source compositions. In contrast, secondary sulfides in Descartes breccia clasts are enriched in chalcophile elements such as Cu, Zn, Ni, Se, and Sb, and represent a potential resource in the lunar highlands.

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.

Investigation of strontium accumulation on ovariectomized Sprague-Dawley rat tibia by micro-PIXE

NASA Astrophysics Data System (ADS)

Li, X.; Li, Y.; Jin, W.; Zheng, Y.; Rong, C.; Lyu, H.; Shen, H.

2014-08-01

Strontium ranelate is a newly developed drug effective in osteoporosis treatment by depressing bone resorption and maintaining bone formation. Strontium accumulation and distribution are determined in bones of rat after strontium ranelate administration by using micro-PIXE. The investigated rats are divided into four groups: (A) control, (B) ovariectomized, (C) ovariectomized followed with strontium chloride, (D) ovariectomized followed with strontium ranelate. It was found that strontium ranelate would result in increasing trabecular volume and decreasing bone resorption to treat osteoporosis. There are similar contours of calcium and strontium in two-dimensional images, while the strontium is not evenly distributed in the bone. It supports the conclusion that strontium has an affinity for bone and it is capable of replacing calcium atoms as a part of the strontium mechanism in the osteoporosis treatment. The results related to biochemistry are also discussed.

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.

Recent developments of ion beam induced luminescence at the external scanning microbeam facility of the LABEC laboratory in Florence

NASA Astrophysics Data System (ADS)

Colombo, E.; Calusi, S.; Cossio, R.; Giuntini, L.; Giudice, A. Lo; Mandò, P. A.; Manfredotti, C.; Massi, M.; Mirto, F. A.; Vittone, E.

2008-04-01

A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps. The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage.

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).

Bio-functionalization of electro-synthesized polypyrrole surface by heme enzyme using a mixture of Nafion and glutaraldehyde as synergetic immobilization matrix: Conformational characterization and electrocatalytic studies

NASA Astrophysics Data System (ADS)

ElKaoutit, Mohammed; Naranjo-Rodriguez, Ignacio; Domínguez, Manuel; Hidalgo-Hidalgo-de-Cisneros, José Luis

2011-10-01

Use of a mixture of Nafion and glutaraldehyde as new immobilization matrix was described. The percentage of Nafion was optimized to prevent denaturation of horseradish peroxidase enzyme after its crosslinkage with glutaraldehyde on electro-synthesized polypyrrole surface. Topographic study by Atomic Force Microscopy (AFM) shows that the enzyme seems to have been introduced inside the ionic cluster of Nafion. The characterization of the resulting bio-interfaces by UV-vis and FT-IR shows that the intra-crosslinkage phenomena caused by the use of glutaraldehyde can be eliminated by the optimization of the concentration of Nafion additive. The secondary structure contents of native and immobilized enzyme were analyzed by a Gaussian curve fitting of the respective FT-IR spectra in the amide I region. Immobilized enzyme presented notable increasing percentages of globular and short helical structure compared with native enzyme. This indicates that immobilized enzyme was folded which is in accordance with AFM studies and supports the enzyme entrance inside ionic clutter of Nafion. Thanks to synergic effects of the polypyrrole conducting polymer and the perfluorosulfonic acid polymer Nafion, HRP enzyme was immobilized in its "native" state, the resulting biosensor was able to sense peroxide without any chemical mediator and can be categorized as third generation.

[Oligonucleotide derivatives in the nucleic acid hybridization analysis. I. Covalent immobilization of oligonucleotide probes onto the nylon].

PubMed

Dmitrienko, E V; Pyshnaia, I A; Pyshnyĭ, D V

2010-01-01

The features of UV-induced immobilization of oligonucleotides on a nylon membranes and the effectiveness of enzymatic labeling of immobilized probes at heterophase detection of nucleic acids are studied. Short terminal oligothymidilate (up to 10 nt) sequences are suggested to attach to the probe via a flexible ethylene glycol based linker. The presence of such fragment enhances the intensity of immobilization and reduces UV-dependent degradation of the targeted (sequence-specific) part of the probe by reducing the dose needed for the immobilization of DNA. The optimum dose of UV-irradiation is determined to be ~0.4 J/cm(2) at the wavelength 254 nm. This dose provides high level of hybridization signal for immobilized probes with various nucleotide composition of the sequence specific moiety. The amide groups of the polyamide are shown to play the key role in the photoinduced immobilization of nucleic acids, whereas the primary amino groups in the structure of PA is not the center responsible for the covalent binding of DNA by UV-irradiation, as previously believed. Various additives in the soaking solution during the membrane of UV-dependent immobilization of probes are shown to influence its effectiveness. The use of alternative to UV-irradiation system of radical generation are shown to provide the immobilization of oligonucleotides onto the nylon membrane.

Novel characteristics of horseradish peroxidase immobilized onto the polyvinyl alcohol-alginate beads and its methyl orange degradation potential.

PubMed

Bilal, Muhammad; Rasheed, Tahir; Iqbal, Hafiz M N; Hu, Hongbo; Wang, Wei; Zhang, Xuehong

2017-12-01

Herein, we report the immobilization of in-house isolated horseradish peroxidase (HRP) from Armoracia rusticana with novel characteristics. The HRP was immobilized onto the self-fabricated polyvinyl alcohol-alginate (PVA-alginate) beads using sodium nitrate as a cross-linker. The PVA-alginate beads (2.0mm size) developed using 10% PVA and 1.5% sodium alginate showed maximal immobilization yield. The surface morphologies of the PVA-alginate (control) and immobilized-HRP were characterized by scanning electron microscopy (SEM). The immobilized-HRP retained 64.14% of its initial activity after 10 consecutive substrate-oxidation cycles as compared to the free counterpart. Simultaneously, the thermal stability of the immobilized-HRP was significantly enhanced as compared to the free HRP. The enzyme leakage (E L ) assay was performed by storing the immobilized-HRP in phosphate buffer solution for 30days. Evidently, the leakage of immobilized-HRP was recorded to be 6.98% and 14.82% after 15 and 30days of incubation, respectively. Finally, the immobilized-HRP was used for methyl orange (MO) dye degradation in a batch mode. A noticeable decline in spectral shift accompanied by no appearance of a new peak demonstrated the complete degradation of MO. The degraded fragments of MO were scrutinized by ultra-performance liquid chromatography coupled with mass spectrometry (UPLC-MS). A plausible degradation pathway for MO was proposed based on the identified intermediates. In conclusion, the study portrays the PVA-alginate-immobilized-HRP as a cost-effective and industrially desirable green catalyst, for biotechnological at large and industrial in particular, especially for the treatment of textile dyes or dye-containing industrial waste effluents. Copyright © 2017 Elsevier B.V. All rights reserved.

A systematic review of postoperative hand therapy management of basal joint arthritis.

PubMed

Wolfe, Terri; Chu, Jennifer Y; Woods, Tammy; Lubahn, John D

2014-04-01

There are a variety of postoperative immobilization and therapy options for patients with basal joint arthritis. Although prior systematic reviews have compared surgical procedures used to treat basal joint arthritis, none to our knowledge compares therapy protocols for this condition, which are considered an important part of the treatment. (1) We sought to determine whether differences in the length and type of postoperative immobilization affect clinical results after basal joint arthritis surgery. (2) We also compared specific therapy protocols that were prescribed. (3) Finally, we evaluated published protocols to determine when patients were released to full activity to see whether these appeared to affect clinical results. A systematic review of English-language studies in the PubMed and Cochrane databases was performed. Studies were then reviewed to determine what postoperative immobilization and therapy protocols the authors used and when patients were released to full activities. A total of 19 studies were identified using the search criteria. All but one of the studies included a postoperative period of immobilization in either a cast or splint. Immobilization time varied depending on whether Kirschner wires were used for the surgery and whether an implant was placed. Postoperative therapy protocols also varied but followed three general patterns. Some therapy protocols involved teaching patients a home exercise program only, whereas some authors described routine referral to a therapist. The third group consisted of studies in which patients were only referred for therapy if the physicians determined it was necessary during followup. Many studies did not give a specific time for full return to activity and instead described a gradual transition to full activity after immobilization was discontinued. Because of the variability and small numbers, no conclusive recommendations could be made on any of the three study questions. Comparative, multicenter studies comparing different immobilization and therapy protocols after the surgical treatment of basal joint arthritis would be helpful for both surgeons and therapists looking to refine their treatment protocols.

Enhancement of algicidal activity by immobilization of algicidal bacteria antagonistic to Stephanodiscus hantzschii (Bacillariophyceae).

PubMed

Kang, Y-H; Kim, B-R; Choi, H J; Seo, J G; Kim, B-H; Han, M-S

2007-11-01

Enhancement of algicidal activity by immobilization of algicidal bacteria antagonistic to Stephanodiscus hantzschii. In laboratory studies, A diatom-lysing bacterium, Pseudomonas fluorescens HYK0210-SK09 showed strong algicidal activity against S. hantzschii, but a natural mesocosm study revealed that this bacterium failed to fully control natural blooms of Stephanodiscus at the low water temperatures that favour these blooms. Here, we sought to develop an effective immobilization strategy for enhancing the algicidal activity of HYK0210-SK09 in the natural setting. Bacterium HYK0210-SK09 was immobilized with various carriers including agar, alginate, polyurethane and cellulose sponge. The bacterial cells immobilized with cellulose sponge (CIS) induced more rapid and complete lysis of S. hantzschii than other carriers, and had a higher packing ability than polyurethane. Furthermore, CIS-immobilized cells showed higher lysis of S. hantzschii at the same concentrations as that of free cells (< or =1 x 10(7) cells ml(-1)), and had especially strong algicidal activity at the low temperatures (<10 degrees C). Based on these laboratory studies, we assessed the possible application of HYK0210-SK09 cells in the field by performing a mesocosm study during the winter season. The CIS-immobilized cells with species-specific activity towards the genera Stephanodiscus showed extremely high algicidal activity (up to 95%) against a bloom of Stephanodiscus hantzschii even at low water temperatures, because of high cell packing and subsequent cell protection against low temperatures and predators, whereas free cells showed negligible algicidal activities under these conditions. Immobilizing cells of HYK0210-SK09 in CIS foam, rather than in the other matrices tested, could achieve more efficient control of Stephanodiscus blooms and showed a significant algicidal activity on in vitro and in vivo blooms, even at low water temperature. Collectively, these results indicate that CIS of algicidal bacteria may form an important strategy for effective management of Stephanodiscus blooms at low water temperatures.

Probing Dynamic Cell-Substrate Interactions using Photochemically Generated Surface-Immobilized Gradients: Application to Selectin-Mediated Leukocyte Rolling

PubMed Central

Herman, Christine T.; Potts, Gregory K.; Michael, Madeline C.; Tolan, Nicole V.

2014-01-01

Model substrates presenting biochemical cues immobilized in a controlled and well-defined manner are of great interest for their applications in biointerface studies that elucidate the molecular basis of cell receptor-ligand interactions. Herein, we describe a direct, photochemical method to generate one-component surface-immobilized biomolecular gradients that are applied to the study of selectin-mediated leukocyte rolling. The technique employs benzophenone-modified glass substrates, which upon controlled exposure to UV light (350 – 365 nm) in the presence of protein-containing solutions facilitate the generation of covalently immobilized protein gradients. Conditions were optimized to generate gradient substrates presenting P-selectin and PSGL-1 (P-selectin Glycoprotein Ligand-1) immobilized at site densities over a 5- to 10-fold range (from as low as ~200 molecules/μm2 to as high as 6000 molecules/μm2). The resulting substrates were quantitatively characterized via fluorescence analysis and radioimmunoassays before their use in the leukocyte rolling assays. HL-60 promyelocytes and Jurkat T lymphocytes were assessed for their ability to tether to and roll on substrates presenting immobilized P-selectin and PSGL-1 under conditions of physiologically relevant shear stress. The results of these flow assays reveal the combined effect of immobilized protein site density and applied wall shear stress on cell rolling behavior. Two-component substrates presenting P-selectin and ICAM-1 (intercellular adhesion molecule-1) were also generated to assess the interplay between these two proteins and their effect on cell rolling and adhesion. These proof-of-principle studies verify that the described gradient generation approach yields well-defined gradient substrates that present immobilized proteins over a large range of site densities that are applicable for investigation of cell-materials interactions, including multi-parameter leukocyte flow studies. Future applications of this enabling methodology may lead to new insights into the biophysical phenomena and molecular mechanism underlying complex biological processes such as leukocyte recruitment and the inflammatory response. PMID:21614364

Production of laccase by Coriolus versicolor and its application in decolorization of dyestuffs: (II). Decolorization of dyes by laccase containing fermentation broth with or without self-immobilized mycelia.

PubMed

Lin, Jian-Ping; Lian, Wei; Xia, Li-Ming; Cen, Pei-Lin

2003-01-01

The capability of decolorization for commercial dyes by Coriolus versicolor fermentation broth containing laccase with or without immobilized mycelium was evaluated. With cell-free fermentation broth containing laccase, high decolorization ratio was achieved foracid orange 7, but not for the other dyes concerned. The immobilized mycelium was proved to be more efficient than the cell-free system. All the four dyestuffs studied were found being decolourized with certain extent by immobilized mycelium. The repeated-batch decolorization was carried out with satisfactory results. The experimental data showed that the continuous decolorization of wastewater from a printing and dyeing industry was possible by using the self-immobilized C. versicolor.

Efficient magnetic recycling of covalently attached enzymes on carbon-coated metallic nanomagnets.

PubMed

Zlateski, Vladimir; Fuhrer, Roland; Koehler, Fabian M; Wharry, Scott; Zeltner, Martin; Stark, Wendelin J; Moody, Thomas S; Grass, Robert N

2014-04-16

In the pursuit of robust and reusable biocatalysts for industrial synthetic chemistry, nanobiotechnology is currently taking a significant part. Recently, enzymes have been immobilized on different nanoscaffold supports. Carbon coated metallic nanoparticles were found to be a practically useful support for enzyme immobilization due to their large surface area, high magnetic saturation, and manipulatable surface chemistry. In this study carbon coated cobalt nanoparticles were chemically functionalized (diazonium chemistry), activated for bioconjugation (N,N-disuccinimidyl carbonate), and subsequently used in enzyme immobilization. Three enzymes, β-glucosidase, α-chymotrypsin, and lipase B were successfully covalently immobilized on the magnetic nonsupport. The enzyme-particle conjugates formed retained their activity and stability after immobilization and were efficiently recycled from milliliter to liter scales in short recycle times.

Bio-functionalization of conductive textile materials with redox enzymes

NASA Astrophysics Data System (ADS)

Kahoush, M.; Behary, N.; Cayla, A.; Nierstrasz, V.

2017-10-01

In recent years, immobilization of oxidoreductase enzymes on electrically conductive materials has played an important role in the development of sustainable bio-technologies. Immobilization process allows the re-use of these bio-catalysts in their final applications. In this study, different methods of immobilizing redox enzymes on conductive textile materials were used to produce bio-functionalized electrodes. These electrodes can be used for bio-processes and bio-sensing in eco-designed applications in domains such as medicine and pollution control. However, the main challenge facing the stability and durability of these electrodes is the maintenance of the enzymatic activity after the immobilization. Hence, preventing the enzyme’s denaturation and leaching is a critical factor for the success of the immobilization processes.